A geo-electrical resistivity survey was carried out around Shendam and its environs to determine the geo-electric sequences and its groundwater potential. A total of twenty eight (28) VES were carried out with current electrode or AB/2 spread ranging from 1.5 to 215 m and potential electrode (MN/2) ranging from 0.5 to 14 m. The interpretation was carried out using the WinResist computer software. The geo-electric sounding interpretation revealed three major geo-electric sequences, which consist of Topsoil, from 0 to 2.9 m, weathered basement (clay/clayey sands/sandy clays) from 2.9 to 50m and bedrock with varying thicknesses from 7 to 33 m and is characterised by resistivity value range categories of 14 to 1497 ohm-m, 10 to 50 ohm-m, and ≥ 1500 ohm-m. The geo-electric parameters from the geo-electric sounding interpretations enabled the preparation of geo-electric sections, isopach of weathered overburden and bedrock relief maps, which assisted in the production of groundwater potential map of the area. This study is expected to form a baseline guide for groundwater exploration and development for Shendam Town and its immediate environs. Keywords: Shendam town, Hydrogeoelectric investigation, Geoelectric sequence, Groundwater potential.

The paper describes an effort to identify the sources and assess the potability of water consumed by pupils in Nursery and Primary schools in Obio/Akpor Local Government Area of Rivers State, Nigeria. The study became necessary since infants are 70% - 80% water and hence the quality of water ingested by pupils plays significant role in their health and wellbeing. Moreover, establishing and running private Nursery and Secondary schools have become a big business not only in Rivers state but throughout Nigeria due mainly to high rate of return on investments in schools. The study showed that water supply for all the schools come from shallow boreholes haphazardly located anywhere on the school premises. Some are located only a few meters away from the septic tanks. Water samples were collected from 17 boreholes in 17 schools located strategically in the 17 wards of Obio-Akpor L.G.A, and analysed for physico-chemical and microbiological characteristics as well as heavy metal concentration using standard methods. The results were compared with the Standard Organisation of Nigeria (SON) and World Health Organisation (WHO) standards for drinking water supply. The study showed that 81% of the parameters studied per sample occurred in acceptable concentration on both WHO and NSO standards for safe drinking water. However, 19% of the parameters namely: pH, alkalinity, iron, magnesium and Total Heterotrophic Bacteria (THB) occur in objectionable concentrations in most of the samples. Magnesium (Mg2+) occurred in excessive concentration (0.4mg/l – 1.8mg/l) in 65% of the samples. This value is 2 -9 times higher than SON (2007) limit of 0.2mg/l. However, Mg2+ was not detected in 35% of the samples. Fe occurred in excessive concentration in 17.6% of the samples and within limits of acceptability in 82.4% of the water samples. Total Heterotrophic Bacteria was high in 41.2% of boreholes while 58.8% of the boreholes had THB within the guideline maximum limit of 10cfu/ml. pH is within acceptable limit in only 6% of the borehole water samples while 94% of the samples showed mild to highly acidic water. The low value of alkalinity (0 -6 mg/l) tend to agree with the acidic nature of the water. This result shows how detrimental the available drinking water is to the health of pupils in the study area. It is concluded that groundwater which forms the only source of water supply to schools in the study area is not, in its untreated form potable. The high acidity and high THB counts renders it unfit for drinking unless treated. Until a treatment system is installed and commissioned, it is strongly recommended that parents equip their wards with larger water containers to take potable water from homes to schools. Schools management should also put up bold inscription by the water taps discouraging innocent pupils from ingesting dilute to strong acid in the name of water.

Investigation of the proposed sites for sanitary landfill within Minna, North-Central Nigeria was carried out using electrical resistivity method. The MacOhms resistivity meter was used to obtain the field data for both 2-dimensional profiling (2D) and 1-dimensional vertical electrical sounding (VES). The investigation was used in the subsurface characterisation of the investigated site in orderto determine its suitability as potential site for sanitary landfill. 2D electrical subsurface imaging was used to determine the lateral and horizontal subsurface lithologic variation at the site. The vertical electrical sounding (VES) curve generated from the study area shows two curve types, which are H and HA with HA showing dominance. Geoelectric sections generated from the VES indicate four lithological layers: top/lateritic layer, clayey soil, the weathered/fractured zone and fresh basement rock. The results indicate the clay layer thickness ranged between2.0m to 5m while the depth to clay layer varied from 5.8m to 9m from the datum point. The findings indicate that the clay soil from the investigated site meets the geotechnical and hydrogeological conditions as barriers for impeding possible leachate migration from sanitary landfill.

In the semiarid Lake Chad Basin (LCB), the transboundary quaternary sedimentary aquifer is the main source of drinking water. Climate variability and the increase in population around the Lake raise concern on the issues of water supply and water management. The knowledge about the availability of groundwater resources in LCB is limited due to the scarcity of information about hydrodynamic parameters of the aquifers. To fill this gap, geophysical surveys based on Magnetic Resonance Sounding (MRS) method were performed in the Yaere aquifer (Northern Cameroon) and in the Kadzell aquifer (Southeastern Niger). The MRS method is a non-invasive technic which has the advantages to be directly sensitive to groundwater, and to allow estimating hydrodynamic parameters. Six representative sites were investigated by MRS (three per aquifer) and are presented in this paper. MRS results are compared to measured piezometric level and to geological description when available. Despite naturally challenging field conditions (high natural electromagnetic noise, and low geomagnetic field), MRS data of good quality were obtained. The piezometric levels estimated with MRS are close to the water level measured in neighboring wells or boreholes. The results also show contrasts in MRS water content and transmissivity in good agreement with expected behavior of aquifers: high values of water content (16%-32%) and transmissivity (2 10-4 m2/s– 4 10-2 m2/s)were recorded near the Lake and the rivers (e.g. near the Komadugu Yobe and the El beid River), and lower values were obtained at distance or in flat clayey areas. These encouraging results promote the use of MRS at the basin scale, to better estimate the available volume of fresh groundwater resources.