The study area, Daura and its environs, is located in Katsina State, northwestern Nigeria. It is defined by longitudes 008° 12' to 008° 26.30'E and latitudes 12° 55' to 13° 09'N with total area of 625km2.\r\n\r\nThe area is underlain by both Crystalline Basement rocks and sedimentary rocks and it lies at the eastern periphery of the Iullemmeden (Sokoto) Basin.\r\n\r\nThe water type in the project area is predominantly alkaline (sodium and potassium) and predominantly chloride (Cl-) and (SO42-) water species.\r\n\r\nGeophysical investigation of Daura town and environs was able to map the groundwater distribution and the extent of infiltration of contaminant plumes from Kwargwam dumpsite, some 250m east of the famous Kusugu well. Geophysical investigation using the electrical method was able to map the groundwater distribution and the extent of infiltration of contaminant plumes from Kwargwam dumpsite, some 250m east of the famous Kusugu well and these conductive plumes have ability to contaminate wells around the dumpsite and even the Kusugu well since contaminant plumes have been reported to infiltrate the subsurface to a depth of 15m into the saturated zones below the water table and could be traceable for over 760m away from dumpsite.\r\n\r\nThe investigations revealed that Daura is endowed with huge industrial and metallic mineral potentials, which can be categorized into four broad groups: aggregate materials (construction); glass sand (silica sand); clays/kaolin and Iron ore. However, it is recommended that the appropriate technology should be employed to effectively harness these mineral potentials so as to enhance the socio-economic well-being of the inhabitants of Daura and its environs.\r\nThe physical and chemical parameters of the water samples conformed to international standards of potable water except for a few water samples having concentrations of certain constituents exceeding the WHO and NSDWQ maximum permissible limits in drinking water, which rendered the water in those localities unfit for human consumption. \r\n\r\nSummary of the recommendations are:\r\n(a) To carry out detailed geotechnical investigation to determine the strength of the clay potential.\r\n(b) Kwagwan dumpsite should be covered up with bentonitic clay or locally sourced clay to prevent further contamination of the groundwater.\r\n(c) The drinking water should be treated with water softening materials in order to reduce its hardness.\r\n\r\n

The project area, Enugu and environs, is defined by Latitudes 60 14' 15" to 60 31' 20" North of the Equator and Longitudes 70 22' to 70 35' 20" East of the Greenwich Meridian. It covers towns and villages such as Ngwo - Enugu, Ukana, Oriemba and Ninth Mile Corner with Enugu urban at the Centre.\r\nThe cuesta is the dominant physiographic feature that trends North-South west of Enugu town. It acts as water divide for groundwater and surface water between the Anambra Basin to the west and the Cross River Basin to the east. The project area falls within the Anambra Basin and is geologically underlain by Agbani Sandstone, Enugu Shales, Mamu, Ajali and Nsukka .Physico-chemical interpretation of groundwater in Enugu

The study area, Abeokuta and its environs, is located in Ogun State, south western Nigeria. It is defined by latitudes 07° 3.0´ to 7° 17.0'N and longitudes 003° 14.0' to 003° 28.0'E and falls within 1:100,000 Sheet 260 Abeokuta and covers an area of 625km2.\r\n\r\nThe objective of the project is to study the hydrogeological characteristics of the area and the impact of waste dumps on the water quality. \r\n\r\nThe area is predominantly underlain by rocks of the Basement Complex and partly by the Cretaceous Sedimentary rocks of the Dahomey Basin. The rocks encountered in order of abundance are migmatized biotite-garnet gneiss, red sand, biotite schist, biotite-garnet-gneiss, coarse porphyritic granite, porphyroblastic gneiss, biotite granite, pegmatite and quartz vein. \r\n\r\nThe physical, chemical and microbial analyses of water samples (surface and groundwater) showed high conductivity, high concentration of trace elements and the presence of pathogens (Esherichia coli) in nearly all the water samples that is within a range of 14 - 180 CFU/ml indicating anthropogenic influence on the groundwater quality. The water samples are all beyond the W.H.O. and S.O.N accepted drinking water standards for human consumption.\r\n\r\nRemediating measures such as provision of pipe-borne water, construction of central sewer system, enactment and enforcement of sanitary bye-laws and location of waste dumpsites are recommended to ameliorate the problems of groundwater pollution in the area. \r\n

Hydrogeology, geology and geophysics were used to study the groundwater potentials of Ibadan and its environs. These potentials include quantity, quality and availability of groundwater to the masses of the people. Due to the factor of affordability, hand dug wells are more in use than deep bore holes which are exclusively for the rich. \r\n\r\nRecords from 690 sample points such as wells, bore holes, streams and the results from ninety-three (93) analyzed water samples form the basis of conclusion and recommendations in this report.\r\n\r\nChemical analysis shows HCO3+CO3 dominated water with low to medium salinity hazard. Nitrate is too low there by allaying the fear of present level of contamination. \r\n\r\nIncident of groundwater contamination by leachates could be a problem in the immediate future because of indiscriminate dumping of solid wastes in unauthorized locations and river system. Lowering of groundwater level due to over extraction should be prevented with appropriate laws. The quality of water is fair as more than half of respondents claim they only use the water for domestic chores except drinking. Microbial contamination is average as most wells lack proper hygiene. \r\n\r\nContinuous monitoring and education is necessary to safe guard the groundwater resources of Ibadan and environs.\r\n

Determination of in-situ soil conditions

Thirty-seven (37) bulk samples taken from a depth of 1.5 meters were analyzed for the determination of Atterberg Limits, Linear Shrinkage, Grain Size Distribution, compaction, and California Bearing Ratio (CBR).\r\n\r\nSixteen (16) borings were made to a depth of 10 meters or to refusal. Standard Penetration Test (SPT) was carried out at every 1.5 meter depth interval and undisturbed samples were collected at the same depth or change of material for Triaxial Compression Test, Grain Size Distribution analysis, and Consolidation. All boreholes stopped at between 1.1m and 5.3 m except borehole 16, cell 056 at NYSC Zonal Office, which went to a maximum depth of 10 meters. \r\n\r\nTen (10) Dynamic Cone Penetrometer (DCP) tests were carried out using a 25mm thin walled pipe with 600 cone. Due to the fine grained nature of the dominantly clayey material, particle size distribution analysis by hydrometer method was employed.\r\n\r\nResults of field and laboratory tests reveal that the entire area on the average is overlain by a 2.5m thick sand, silt, and clay, with spot clay deposits notably at cells 056 (NYSC Zonal office) and 047 (Railway quarters). Soils of Gombe can be classified into nine groups, A-3, A-4, A-5, A-6, A-7, A-1-b, A-2-4, A-2-6, and A-2-7. Of the 37 samples analyzed, 18 are sands and hence non-plastic, 2 are silts and plotted below the A-line on the plasticity chart, while17 others are clays and plotted above the A-line.\r\nResults of SPT tests at cell 001 to 060 gave blow count (N) values of between 2 and 100 with calculated corrected N-values (N?) of between 2 and 58, at 0.5m, 1.5m, 3.0m, with maximum depth of 10m at NYSC Zonal Office. Apart from the boring at NYSC Zonal office, all borings terminated at between 1.1m to 5.3m.\r\nFrom the bulk samples recovered at 1.5m depth, bearing capacity computations based on Triaxial Compression test gave values between 277kN/m2 and 2545 kN/m2. \r\nConsolidation test results show that the materials are of medium to high compressibility. About 90% consolidation occurred within 40-120 metres, indicating secondary settlement upon application of load. The 24-hour soaked California Bearing Ratio (CBR) values between 5.1% and 11.2% shows the materials are good to be used for road subgrade. Values of maximum Dry Density (MDD) ranging between 1.09Mg/m3 and 2.17Mg/m3 with optimum moisture content (OMC) ranging from 9.5% to 19.8% were recorded. Linear shrinkage test shows low shrinkage for the sandy material, and shrinkage of up to 14% for the dominantly clayey materials. \r\n\r\nCivil constructions in Gombe require strict adherence to building standards and the findings of this work in the light of the thick clay that underlies most part of the state capital. This can go a long way in reducing incidence of multiple cracked buildings that are scattered all over the area. \r\n

Determination of in-situ soil conditions

Determination of in-situ soil conditions

Determination of in-situ soil conditions

The project area covers Benin City and its environs in Edo State , South-South Nigeria. The area lies from Latitudes 60 15' to 60 27' N, and from Longitude 5030' to 5 045'; and covers an area of 610Km2. The area falls within 1:100,000 Sheet 298 (Benin City).\r\n\r\nThe purpose of the project is to study the effects of waste dumps on the quality of surface and groundwater in Benin City and environs. The methods adopted were geological mapping, hydrogeological mapping, soil sampling, geophysical studies and laboratory analysis of water samples. \r\n\r\nThe area is underlain by the Benin Formation. The formation is recognized by upper horizon of reddish brown to yellowish brown sand, and at the base by yellowish to white loose gravely to pebbly sand with discontinuous beds of clay. Its maximum thickness is about 1829m, and about 800m in Benin City. The formation has a single aquifer system and it is highly permeable, porous and prolific in water yield. \r\n\r\nA total of one hundred and two (102) samples were collected and analyzed for the study. Results for physiochemical parameters showed that the pH ranges from 5.79 to 7.26 with the highest value recorded in the rain-water and the lowest in the borehole water. This indicates that the waters in the area are moderately acidic to neutral. Conductivity ranges from 5µS/cm to 663 µS/cm. TDS values range from 2mg/l to 330mg/l. The values for conductivity corresponded to the values for TDS. The colour of the river waters were pale yellow, while those of the rain, borehole and well waters were colourless. The pale yellow colour of the river waters indicates impurities which could be from waste dumps. Chemically, all the values of the major cations and anions fell within the World Health Organization (WHO) permissible limits for potable water. \r\n\r\nThe dominant cation is calcium while the dominant anion is chloride. Concentration of Nitrate was observed in the waters with relative high values in the well waters. This is because effluent easily attenuates before reaching the deep aquifers. Similarly, coliforms were detected in the water samples except in rain-water. The presence of nitrate and coliform in water indicates some measure of contamination. Concentrations of some trace elements were above the WHO (2006) permissible limits. The trace elements include Fe, AS, Cd, Mn, and Pb. The high values of these trace elements in the waters indicate some measure of contamination. This contamination could be as a result of leachate from waste dumps in the area. The leachate from the waste dumps infiltrates into the groundwater as a result of the porous and permeable nature of the sandstone underlying the area.\r\n\r\nIt was however recommended that surface and groundwater monitoring should be done regularly in the area and that the dumpsites should be converted to concrete landfills for easy control of leachate infiltration into the surface and ground waters in the area.\r\n