This study involves the determination of the hydrochemistry of groundwater and its suitability for drinking, domestic and other purposes in the area. Results show that Hardness range between 2.53mg/l -5.06mg/l with a mean value of 3.69mg/l, indicating that the water from the area is soft. Electrical conductivity (EC) level ranges from 6.23µS/cm -13.74µS/cm with a mean of 9.80µS/cm. pH range from 6.50 -6.86 with a mean value of 6.66, indicating slightly acidic water. TDS range from 5.77mg/l -18.30mg/l with a mean value of 11.4.1mg/l. Temp ranges from 26°C -27°C with a mean value of 26.6°C. Calcium (Ca The dominant cation and anion in the groundwater from the study area are Ca 2+ and HCO 3 -respectively. The ions owe their origin to rainfall and dissolution of minerals from the Benin Formation where the wells tap from. It is recommended that seasonal variation of groundwater chemistry studies be carried out regularly to detect any future degradation in the area and the results would be used for decision and policy making.

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

A study of groundwater potential of Pompo Village in the neighborhood of Gidan Kwano campus of Federal University of Technology, Minna, was carried out using Vertical Electrical Resistivity Sounding. A total of 12 Vertical Electrical Soundings (VES) were carried out across the area using the Schlumberger electrode array configuration. The sounding data was processed and interpreted using ZODDY and WINRESIST interpretation software. The underlying geo-electric section comprising topsoil, weathered basement, fractured basement and fresh basement was established. The Vertical Electrical Sounding curves revealed that the area is generally characterized by five geo-electric layers. The top soil layer is a highly resistive layer with thickness ranging from 0.3m to 1.6m. The second geo-electric layer is a resistive dry layer with thickness ranging from 0.9m to 4.3m. The weathered basement layer thickness varies from 0.9m to 9.1m. The fractured basement ranges from 2.1m to 16.4m in thickness, while the depth to basement varies between 4.9m and 25.3m. Out of the 12 VES carried out, 5 VES stations have been chosen as the most viable locations for the development of groundwater resources. Two types of aquifers, which are the weathered basement and fractured basement aquifer, have been delineated in this study. These aquifer units may have significant groundwater potential.

Groundwater has been recognized as playing a very important role in the development of Abuja, Nigeria's Capital as many households, private and government establishments depends solely on hand-dug wells and boreholes for their daily water needs. Exploitation of groundwater is rather delicate because of its potency to contamination and difficulty to remediate when compared to surface water. The purpose of this paper is to present the occurrence of nitrate in groundwater of Abuja and discuss the implication and sources of the nitrate. High nitrate level in drinking water leads to infant methaemoglobinaemia (blue-baby syndrome), gastric cancer, metabolic disorder and livestock poisoning. A simplified map of nitrate occurrences in Abuja indicates that some areas have nitrate concentration above the WHO and NSDWQ guide limit of 50 mg/l and it is dominant in the rainy season than dry season. The number of people drinking water with nitrate concentration above the permissible level cannot be quantified presently. The sources of nitrate in the groundwater were attributed to bedrock dissolution in the course of groundwater migration and more importantly anthropogenic activities such as on-site sanitation, waste dumpsites and agricultural chemicals. Water treatment by bio-denitrification and nitrate pollution control programs should be introduced at local, state and federal levels in order to educate people on the need to protect groundwater from nitrate pollution caused by agricultural activity and indiscriminate disposal of wastes.Keywords: anthropogenic activity, nitrate pollution, groundwater, Abuja IntroductionThe problem of nitrate pollution in groundwater is a common global phenomenon and has been reported by various authors in many parts of Nigeria (Egboka & Ezeonu, 1990;Uma, 1993;Edet, 2000;Adelana & Olasehinde, 2003;Amadi, 2010). The presence of nitrate in groundwater can be derived from natural and/or anthropogenic sources. The soil/rock-water interactions can result to weathering and enrichment of the groundwater with ammonium ions, since groundwater quality is a function of the chemical composition of the soil/rock through which it passes (Amadi, 2010). The chemistry of groundwater is generally conditioned by the nature of the rock formation through which it flows. The sources and distribution of nitrate in groundwater have been studied in some details in Botswana (Staudt, 2003;Vogel et al., 2004;Schiwiede et al., 2005;Stadler, 2005), Namibia (Heaton, 1984;Wrabel, 2005) and South Africa (Tredoux, 2004;Tredoux et al., 2005). These studies have shown that pollution by anthropogenic activities is the main source of high and variable levels in groundwater. Such activities includes inappropriate on-site sanitation and wastewater treatment, improper sewage sludge drying and disposal, livestock concentration at watering points near boreholes and farming activities by application of nitrogenous fertilizers.

In this study, metal pollution index (MPI) and principal component analysis (PCA) techniques were applied to water quality data sets obtained from River Chanchaga, Minna, North-central Nigeria, to obtain the spatial and temporal changes in the river quality. Results show that the indices which changed the quality of the river water consist of natural (weathering and bedrock dissolution) and anthropogenic activities such as mining, agriculture, domestic and industrial wastes within its catchment. The result of the MPI indicates that the river is slightly affected with respect to heavy metal pollution, which can be attributed the gold mineralization and mining along the river course. Five principal factors were generated when the data was subjected to PCA and they correspond to five possible point source of pollution to the river. Factors 1 and 2 are naturally induced while factors 3, 4 and 5 are due to anthropogenic interference in the hydrological cycle. Although, the river quality does not pose any serious threat to human health presently, the various anthropogenic activities domiciled at the downstream should discontinue, in order restore the river water quality. The people living close to the river should adopt a good sanitary habit by not dumping waste into the river henceforth. Boiling of the water before consumption is advocated.