Determination of in-situ soil conditions

Physico-chemical interpretation of groundwater in Onitsha

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

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

Effect of rock-water interactions in Calabar area

The study area is between Latitudes 080 46' - 090 00'E and Longitudes 090 48' - 10 02'N and covers an area of about 635km2. The area covers about 5 local governments: Jos North, Jos South, Jos East, Bassa and some parts of Toro Local Government in Bauchi state. \r\n\r\nThe topography of the area is virtually undulating. The undulations are due to the rocky nature of the terrain and several water paths that follow the basement structure. The area is covered with high relief older granite plutons and younger granite ring complexes.\r\n\r\nThe geology of this area can be divided into six major lithological groups: (i) the precambrian migmatites and granite gneisses of the basement complex covering an area of about 97km2 (i.e. 15%) in the Central and Northern parts of the map; (ii) the pan-African older granites comprising of coarse porphyritic biotite and biotite hornblende granite and fine grained biotite granite occupying an area of about 83km2 (i.e. 13%) in the Western margin and Central part of the map; (iii) the Jurassic younger granite series comprising of granite and porphyries occupying an area of about 349km2 (i.e. 55%) in the Central, South East, North West and North Eastern parts of the map; (iv) the late cretaceous older basalts occupying an area of about 25km2 (i.e. 4%) in the South-Western and North Western parts of the map (v) the late tertiary/quartenary newer basalts occupying an area of about 36km2 (i.e. 10%) in the Central part of the map; and (vi) the Neogene sediments (Alluvium) occupying an area of about 25km2 (i.e. 4%) along the rivers in the entire area.\r\n\r\nStreams, rivers, springs and mining ponds provide the surface water resources of the area. The major Rivers in the area are River Bauna, River Dilimi, River Tilden Fulani, River Rukuba, River Gell and Shen River. The drainage pattern of all the rivers and streams in the area is controlled by chains of mountains and hills of high relief on the Jos Plateau. \r\n \r\nGroundwater in this area occurs in 4 different aquifer types: (i) the weathered or overburden or regolith aquifer (ii) the fractured basement rock aquifer (iii) the alluvium aquifer and (iv) the fluvio-volcanic aquifer. The overburden or regolith aquifer is the main aquifer in the study area which provides water to about 95% of the population via hand-dug wells. The aquifer is unconfined. It is discontinuous due to the rocky nature of the area. It is generally clayey. It is porous but not very permeable. The water table ranges from less than 3m in the rainy season to a maximum of 10m in the dry season. The younger granite in the study area is characterized by a pronounced set of open joints which show a persistent northerly trend and contain a lot of water. As a result shallow ground water occurs almost every where in the decomposed zone (regolith aquifer) overlying the fresh rock. This is extremely developed for domestic purposes by means of numerous hand-dug wells.\r\n\r\nThe electrical resistivity survey carried out at 16 locations in the area shows that the basement rocks of Jos appear to be highly weathered and fractured hence, the area has high water potential. The survey also shows that the depth to the probable aquiferous layer varies between 9.4m and 42. 5m. Since the basement in the study area is shallow and in most cases fractured, contaminants/leachates could easily find their way to pollute the ground water. \r\n\r\nThe waters in the wells and streams of Jos town and its surroundings villages are dominantly calcium bicarbonate (Ca-HCO3) and sodium chloride bicarbonate (Na-Cl-HCO3) waters. This is because of the dominance of Ca++, Cl-, Na+ and HCO3- ions in the waters. \r\n\r\nThe regolith aquifers in the surrounding villages and some parts of Jos town (like the G. R. A and millionaires quarters) show relatively low mineral content (TDS of 4.83 to 169 ppm) while concentrations in excess of 958 ppm occur within the congested parts of Jos town where land surface derived wastes contribute to the excess. \r\n\r\n94% of the water samples are slightly acidic with the pH range of 5.1 - 6.9 while 6% of samples are slightly alkaline with the pH range of 7.1 - 8.8. The moderately low pH values (i.e. 5.1 - 6.9) or the slightly acidic nature of the samples may be due to the clay rich nature of the overburden weathered sediments of the basement rocks. The pH values of water samples in the study area (i.e. 5.1 - 7.88) have nearly fallen within the permissible range for drinking water recommended by WHO, NAFDAC and NPDWR (USA) which are 7.0 - 8.5, 6.5 - 8.5 and 6.5 - 8.5 respectively. Therefore, in terms of pH, the waters in the regolith aquifers in the study area are good for drinking, washing and cooking. \r\n\r\nThe amount of all the cations and anions present in the waters of all the hand-dug wells and streams studied cannot pose any problem, as regards drinking washing, bathing and other domestic uses when compared with the WHO, NAFDAC and NPDWR (USA) standards for drinking water. The waters are also free from deleterious metals like copper and arsenic. The waters that contain high total dissolved solids in the study area were found to contain a lot chloride and nitrate. The chloride is in excess of 172 mg/liter at location 282 (Dodo Street) and the Nitrate is in excess of 43 mg/liter at location 289 (Abba Na Shehu Street). This is due to the leachates from the numerous waste dumps around as confirmed by the medium permeability of the 4 soil samples collected from the bottoms of 4 refuse dumps in this area. The presence of nitrates in all the samples is a sign of pollution from inorganic wastes and fertilizers used in the farms.\r\n\r\nGenerally, the levels of faecal pollution in the well waters of Jos town and the surrounding villages are high. This could be connected to the (i) siting of wells near pit latrines or septic tanks or refuse damps; (ii) using contaminated containers to fetch water; (iii) throwing of containers used for fetching water on the ground near the wells when not in use; (iv) washing dishes near the wells (v) leaving the wells open when not in use; (v) presence of animals and chickens near the well.\r\nThe study area is between Latitudes 080 46' - 090 00'E and Longitudes 090 48' - 10 02'N and covers an area of about 635km2. The area covers about 5 local governments: Jos North, Jos South, Jos East, Bassa and some parts of Toro Local Government in Bauchi state. \r\n\r\nThe topography of the area is virtually undulating. The undulations are due to the rocky nature of the terrain and several water paths that follow the basement structure. The area is covered with high relief older granite plutons and younger granite ring complexes.\r\n\r\nThe geology of this area can be divided into six major lithological groups: (i) the precambrian migmatites and granite gneisses of the basement complex covering an area of about 97km2 (i.e. 15%) in the Central and Northern parts of the map; (ii) the pan-African older granites comprising of coarse porphyritic biotite and biotite hornblende granite and fine grained biotite granite occupying an area of about 83km2 (i.e. 13%) in the Western margin and Central part of the map; (iii) the Jurassic younger granite series comprising of granite and porphyries occupying an area of about 349km2 (i.e. 55%) in the Central, South East, North West and North Eastern parts of the map; (iv) the late cretaceous older basalts occupying an area of about 25km2 (i.e. 4%) in the South-Western and North Western parts of the map (v) the late tertiary/quartenary newer basalts occupying an area of about 36km2 (i.e. 10%) in the Central part of the map; and (vi) the Neogene sediments (Alluvium) occupying an area of about 25km2 (i.e. 4%) along the rivers in the entire area.\r\n\r\nStreams, rivers, springs and mining ponds provide the surface water resources of the area. The major Rivers in the area are River Bauna, River Dilimi, River Tilden Fulani, River Rukuba, River Gell and Shen River. The drainage pattern of all the rivers and streams in the area is controlled by chains of mountains and hills of high relief on the Jos Plateau. \r\n \r\nGroundwater in this area occurs in 4 different aquifer types: (i) the weathered or overburden or regolith aquifer (ii) the fractured basement rock aquifer (iii) the alluvium aquifer and (iv) the fluvio-volcanic aquifer. The overburden or regolith aquifer is the main aquifer in the study area which provides water to about 95% of the population via hand-dug wells. The aquifer is unconfined. It is discontinuous due to the rocky nature of the area. It is generally clayey. It is porous but not very permeable. The water table ranges from less than 3m in the rainy season to a maximum of 10m in the dry season. The younger granite in the study area is characterized by a pronounced set of open joints which show a persistent northerly trend and contain a lot of water. As a result shallow ground water occurs almost every where in the decomposed zone (regolith aquifer) overlying the fresh rock. This is extremely developed for domestic purposes by means of numerous hand-dug wells.\r\n\r\nThe electrical resistivity survey carried out at 16 locations in the area shows that the basement rocks of Jos appear to be highly weathered and fractured hence, the area has high water potential. The survey also shows that the depth to the probable aquiferous layer varies between 9.4m and 42. 5m. Since the basement in the study area is shallow and in most cases fractured, contaminants/leachates could easily find their way to pollute the ground water. \r\n\r\nThe waters in the wells and streams of Jos town and its surroundings villages are dominantly calcium bicarbonate (Ca-HCO3) and sodium chloride bicarbonate (Na-Cl-HCO3) waters. This is because of the dominance of Ca++, Cl-, Na+ and HCO3- ions in the waters. \r\n\r\nThe regolith aquifers in the surrounding villages and some parts of Jos town (like the G. R. A and millionaires quarters) show relatively low mineral content (TDS of 4.83 to 169 ppm) while concentrations in excess of 958 ppm occur within the congested parts of Jos town where land surface derived wastes contribute to the excess. \r\n\r\n94% of the water samples are slightly acidic with the pH range of 5.1 - 6.9 while 6% of samples are slightly alkaline with the pH range of 7.1 - 8.8. The moderately low pH values (i.e. 5.1 - 6.9) or the slightly acidic nature of the samples may be due to the clay rich nature of the overburden weathered sediments of the basement rocks. The pH values of water samples in the study area (i.e. 5.1 - 7.88) have nearly fallen within the permissible range for drinking water recommended by WHO, NAFDAC and NPDWR (USA) which are 7.0 - 8.5, 6.5 - 8.5 and 6.5 - 8.5 respectively. Therefore, in terms of pH, the waters in the regolith aquifers in the study area are good for drinking, washing and cooking. \r\n\r\nThe amount of all the cations and anions present in the waters of all the hand-dug wells and streams studied cannot pose any problem, as regards drinking washing, bathing and other domestic uses when compared with the WHO, NAFDAC and NPDWR (USA) standards for drinking water. The waters are also free from deleterious metals like copper and arsenic. The waters that contain high total dissolved solids in the study area were found to contain a lot chloride and nitrate. The chloride is in excess of 172 mg/liter at location 282 (Dodo Street) and the Nitrate is in excess of 43 mg/liter at location 289 (Abba Na Shehu Street). This is due to the leachates from the numerous waste dumps around as confirmed by the medium permeability of the 4 soil samples collected from the bottoms of 4 refuse dumps in this area. The presence of nitrates in all the samples is a sign of pollution from inorganic wastes and fertilizers used in the farms.\r\n\r\nGenerally, the levels of faecal pollution in the well waters of Jos town and the surrounding villages are high. This could be connected to the (i) siting of wells near pit latrines or septic tanks or refuse damps; (ii) using contaminated containers to fetch water; (iii) throwing of containers used for fetching water on the ground near the wells when not in use; (iv) washing dishes near the wells (v) leaving the wells open when not in use; (v) presence of animals and chickens near the well.\r\nThe study area is between Latitudes 080 46' - 090 00'E and Longitudes 090 48' - 10 02'N and covers an area of about 635km2. The area covers about 5 local governments: Jos North, Jos South, Jos East, Bassa and some parts of Toro Local Government in Bauchi state. \r\n\r\nThe topography of the area is virtually undulating. The undulations are due to the rocky nature of the terrain and several water paths that follow the basement structure. The area is covered with high relief older granite plutons and younger granite ring complexes.\r\n\r\nThe geology of this area can be divided into six major lithological groups: (i) the precambrian migmatites and granite gneisses of the basement complex covering an area of about 97km2 (i.e. 15%) in the Central and Northern parts of the map; (ii) the pan-African older granites comprising of coarse porphyritic biotite and biotite hornblende granite and fine grained biotite granite occupying an area of about 83km2 (i.e. 13%) in the Western margin and Central part of the map; (iii) the Jurassic younger granite series comprising of granite and porphyries occupying an area of about 349km2 (i.e. 55%) in the Central, South East, North West and North Eastern parts of the map; (iv) the late cretaceous older basalts occupying an area of about 25km2 (i.e. 4%) in the South-Western and North Western parts of the map (v) the late tertiary/quartenary newer basalts occupying an area of about 36km2 (i.e. 10%) in the Central part of the map; and (vi) the Neogene sediments (Alluvium) occupying an area of about 25km2 (i.e. 4%) along the rivers in the entire area.The Federal Government of Nigeria should formulate a stringent regulation to force the states Governments to always design, construct and monitor landfills in their states and also to force their people to take the refuse collected to the designated landfills.\r\n\r\nStreams, rivers, springs and mining ponds provide the surface water resources of the area. The major Rivers in the area are River Bauna, River Dilimi, River Tilden Fulani, River Rukuba, River Gell and Shen River. The drainage pattern of all the rivers and streams in the area is controlled by chains of mountains and hills of high relief on the Jos Plateau. \r\n \r\nGroundwater in this area occurs in 4 different aquifer types: (i) the weathered or overburden or regolith aquifer (ii) the fractured basement rock aquifer (iii) the alluvium aquifer and (iv) the fluvio-volcanic aquifer. The overburden or regolith aquifer is the main aquifer in the study area which provides water to about 95% of the population via hand-dug wells. The aquifer is unconfined. It is discontinuous due to the rocky nature of the area. It is generally clayey. It is porous but not very permeable. The water table ranges from less than 3m in the rainy season to a maximum of 10m in the dry season. The younger granite in the study area is characterized by a pronounced set of open joints which show a persistent northerly trend and contain a lot of water. As a result shallow ground water occurs almost every where in the decomposed zone (regolith aquifer) overlying the fresh rock. This is extremely developed for domestic purposes by means of numerous hand-dug wells.\r\n\r\nThe electrical resistivity survey carried out at 16 locations in the area shows that the basement rocks of Jos appear to be highly weathered and fractured hence, the area has high water potential. The survey also shows that the depth to the probable aquiferous layer varies between 9.4m and 42. 5m. Since the basement in the study area is shallow and in most cases fractured, contaminants/leachates could easily find their way to pollute the ground water. \r\n\r\nThe waters in the wells and streams of Jos town and its surroundings villages are dominantly calcium bicarbonate (Ca-HCO3) and sodium chloride bicarbonate (Na-Cl-HCO3) waters. This is because of the dominance of Ca++, Cl-, Na+ and HCO3- ions in the waters. \r\n\r\nThe regolith aquifers in the surrounding villages and some parts of Jos town (like the G. R. A and millionaires quarters) show relatively low mineral content (TDS of 4.83 to 169 ppm) while concentrations in excess of 958 ppm occur within the congested parts of Jos town where land surface derived wastes contribute to the excess. \r\n\r\n94% of the water samples are slightly acidic with the pH range of 5.1 - 6.9 while 6% of samples are slightly alkaline with the pH range of 7.1 - 8.8. The moderately low pH values (i.e. 5.1 - 6.9) or the slightly acidic nature of the samples may be due to the clay rich nature of the overburden weathered sediments of the basement rocks. The pH values of water samples in the study area (i.e. 5.1 - 7.88) have nearly fallen within the permissible range for drinking water recommended by WHO, NAFDAC and NPDWR (USA) which are 7.0 - 8.5, 6.5 - 8.5 and 6.5 - 8.5 respectively. Therefore, in terms of pH, the waters in the regolith aquifers in the study area are good for drinking, washing and cooking. \r\n\r\nThe amount of all the cations and anions present in the waters of all the hand-dug wells and streams studied cannot pose any problem, as regards drinking washing, bathing and other domestic uses when compared with the WHO, NAFDAC and NPDWR (USA) standards for drinking water. The waters are also free from deleterious metals like copper and arsenic. The waters that contain high total dissolved solids in the study area were found to contain a lot chloride and nitrate. The chloride is in excess of 172 mg/liter at location 282 (Dodo Street) and the Nitrate is in excess of 43 mg/liter at location 289 (Abba Na Shehu Street). This is due to the leachates from the numerous waste dumps around as confirmed by the medium permeability of the 4 soil samples collected from the bottoms of 4 refuse dumps in this area. The presence of nitrates in all the samples is a sign of pollution from inorganic wastes and fertilizers used in the farms.\r\n\r\nGenerally, the levels of faecal pollution in the well waters of Jos town and the surrounding villages are high. This could be connected to the (i) siting of wells near pit latrines or septic tanks or refuse damps; (ii) using contaminated containers to fetch water; (iii) throwing of containers used for fetching water on the ground near the wells when not in use; (iv) washing dishes near the wells (v) leaving the wells open when not in use; (v) presence of animals and chickens near the well.\r\nThe study area is between Latitudes 080 46' - 090 00'E and Longitudes 090 48' - 10 02'N and covers an area of about 635km2. The area covers about 5 local governments: Jos North, Jos South, Jos East, Bassa and some parts of Toro Local Government in Bauchi state. \r\n\r\nThe topography of the area is virtually undulating. The undulations are due to the rocky nature of the terrain and several water paths that follow the basement structure. The area is covered with high relief older granite plutons and younger granite ring complexes.\r\n\r\nThe geology of this area can be divided into six major lithological groups: (i) the precambrian migmatites and granite gneisses of the basement complex covering an area of about 97km2 (i.e. 15%) in the Central and Northern parts of the map; (ii) the pan-African older granites comprising of coarse porphyritic biotite and biotite hornblende granite and fine grained biotite granite occupying an area of about 83km2 (i.e. 13%) in the Western margin and Central part of the map; (iii) the Jurassic younger granite series comprising of granite and porphyries occupying an area of about 349km2 (i.e. 55%) in the Central, South East, North West and North Eastern parts of the map; (iv) the late cretaceous older basalts occupying an area of about 25km2 (i.e. 4%) in the South-Western and North Western parts of the map (v) the late tertiary/quartenary newer basalts occupying an area of about 36km2 (i.e. 10%) in the Central part of the map; and (vi) the Neogene sediments (Alluvium) occupying an area of about 25km2 (i.e. 4%) along the rivers in the entire area.\r\n\r\nStreams, rivers, springs and mining ponds provide the surface water resources of the area. The major Rivers in the area are River Bauna, River Dilimi, River Tilden Fulani, River Rukuba, River Gell and Shen River. The drainage pattern of all the rivers and streams in the area is controlled by chains of mountains and hills of high relief on the Jos Plateau. \r\n \r\nGroundwater in this area occurs in 4 different aquifer types: (i) the weathered or overburden or regolith aquifer (ii) the fractured basement rock aquifer (iii) the alluvium aquifer and (iv) the fluvio-volcanic aquifer. The overburden or regolith aquifer is the main aquifer in the study area which provides water to about 95% of the population via hand-dug wells. The aquifer is unconfined. It is discontinuous due to the rocky nature of the area. It is generally clayey. It is porous but not very permeable. The water table ranges from less than 3m in the rainy season to a maximum of 10m in the dry season. The younger granite in the study area is characterized by a pronounced set of open joints which show a persistent northerly trend and contain a lot of water. As a result shallow ground water occurs almost every where in the decomposed zone (regolith aquifer) overlying the fresh rock. This is extremely developed for domestic purposes by means of numerous hand-dug wells.\r\n\r\nThe electrical resistivity survey carried out at 16 locations in the area shows that the basement rocks of Jos appear to be highly weathered and fractured hence, the area has high water potential. The survey also shows that the depth to the probable aquiferous layer varies between 9.4m and 42. 5m. Since the basement in the study area is shallow and in most cases fractured, contaminants/leachates could easily find their way to pollute the ground water. \r\n\r\nThe waters in the wells and streams of Jos town and its surroundings villages are dominantly calcium bicarbonate (Ca-HCO3) and sodium chloride bicarbonate (Na-Cl-HCO3) waters. This is because of the dominance of Ca++, Cl-, Na+ and HCO3- ions in the waters. \r\n\r\nThe regolith aquifers in the surrounding villages and some parts of Jos town (like the G. R. A and millionaires quarters) show relatively low mineral content (TDS of 4.83 to 169 ppm) while concentrations in excess of 958 ppm occur within the congested parts of Jos town where land surface derived wastes contribute to the excess. \r\n\r\n94% of the water samples are slightly acidic with the pH range of 5.1 - 6.9 while 6% of samples are slightly alkaline with the pH range of 7.1 - 8.8. The moderately low pH values (i.e. 5.1 - 6.9) or the slightly acidic nature of the samples may be due to the clay rich nature of the overburden weathered sediments of the basement rocks. The pH values of water samples in the study area (i.e. 5.1 - 7.88) have nearly fallen within the permissible range for drinking water recommended by WHO, NAFDAC and NPDWR (USA) which are 7.0 - 8.5, 6.5 - 8.5 and 6.5 - 8.5 respectively. Therefore, in terms of pH, the waters in the regolith aquifers in the study area are good for drinking, washing and cooking. \r\n\r\nThe amount of all the cations and anions present in the waters of all the hand-dug wells and streams studied cannot pose any problem, as regards drinking washing, bathing and other domestic uses when compared with the WHO, NAFDAC and NPDWR (USA) standards for drinking water. The waters are also free from deleterious metals like copper and arsenic. The waters that contain high total dissolved solids in the study area were found to contain a lot chloride and nitrate. The chloride is in excess of 172 mg/liter at location 282 (Dodo Street) and the Nitrate is in excess of 43 mg/liter at location 289 (Abba Na Shehu Street). This is due to the leachates from the numerous waste dumps around as confirmed by the medium permeability of the 4 soil samples collected from the bottoms of 4 refuse dumps in this area. The presence of nitrates in all the samples is a sign of pollution from inorganic wastes and fertilizers used in the farms.\r\n\r\nGenerally, the levels of faecal pollution in the well waters of Jos town and the surrounding villages are high. This could be connected to the (i) siting of wells near pit latrines or septic tanks or refuse damps; (ii) using contaminated containers to fetch water; (iii) throwing of containers used for fetching water on the ground near the wells when not in use; (iv) washing dishes near the wells (v) leaving the wells open when not in use; (v) presence of animals and chickens near the well.\r\n

Determination of in-situ soil conditions

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

The study area, Katsina town and its environs, is located in Katsina State, northwestern Nigeria. It is defined by longitudes 7° 30'E to 7° 45'E and latitudes 12° 52' 10"N to 13° 07' 10"N with a total area of 625km2.\r\n\r\nThe objective of the project was to study the hydrogeochemical characteristics of water in the area and the impact of waste dumps on the water quality. The methods adopted for the project were geological mapping, geophysical studies, hydrogeological mapping and waste management assessment coupled with laboratory analyses of water and soil samples.\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. The conglomeratic sandstone of Gundumi formation constitute the aquifer in the sedimentary area while the weathered overburden, fractured and jointed zones constitute the aquifers in the basement underlain areas as revealed by geophysical studies.\r\n\r\nThe water type in the project area is earth-alkaline (calcium and magnesium) and predominantly chloride (Cl-) and bicarbonate (HCO3-) water species.\r\n\r\nThere is no officially-designated waste dumpsite(s) in the project area, which resulted in indiscriminate dumping of wastes in unapproved sites such as road sides, drains, streams and river channels. Handdug wells, hand pump boreholes and deep boreholes are located indiscriminately close to dumpsites, latrines, septic tanks and drains.\r\n\r\nThe physical and chemical parameters of the water samples particularly those of the groundwater conformed with international standards of potable water except groundwater in the vicinity of dumpsites, that had electrical conductivity, total dissolved solids, nitrate, chloride and Coliform Counts exceeding the WHO and SON maximum permissible limits in drinking water, which rendered the water unfit for human consumption, unless treated.\r\n\r\n\r\n