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 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

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

Physico-chemical interpretation of groundwater in Onitsha

The study area lies between latitudes 100 26' to 100 40'N and longitudes 70 19' to 70 33'E with a total surface area of 630km2. The major town in the study area is Kaduna, which is the capital of Kaduna State.\r\n\r\nThe area is underlain by the Nigerian Basement Complex. The dominant rock types are the migmatite-gneiss complex and the Older Granites, which intruded the host gneissic rocks. Prolonged in-situ weathering of the crystalline Basement Complex rocks under tropical conditions has produced a sequence of unconsolidated material (laterites) whose thickness and lateral extent vary extensively. \r\n\r\nThere are three major aquifers in the study area namely weathered overburden aquifer, fractured bedrock aquifer and the stream alluvial deposits aquifer. The three aquifers are interconnected and form one hydraulic system with unconfined water table. \r\n\r\nEighty-eight (88) hand-dug wells, with depths ranging from 0.2 to 11.6m, were studied and thirty-four (34) representative water samples were analyzed in the laboratory. The results were compared with WHO (2006) and NAFDAC standards for drinking water. \r\n\r\nResults of physical parameters showed pH ranged from 4.83 to 7.80, electrical conductivity from 20-980µS/cm and TDS from 10-490mg/l. Results of the cations showed Na+ varied from 1.66-221.20mg/l, Ca2+ from 0.23-92.00mg/l, Mg2+ from 0.12-154.00mg/l, K+ from 0.72-71.48mg/l, Fe2+ from 0.02mg/-0.22mg/l and Pb2+ from 0.18-0.95 mg/l. Results of the anions showed Cl- ranged from 2.67-176.94 mg/l, SO42- from 1.00-250 mg/l, NO3-from 0.05-55.00mg/l ,CO32- from 4.80-50.40mg/l and HCO3- from 2.40-62.00mg/l. Result of the microbial analysis showed Cfu/ml varied from 80-240. The concentration values of the cations and anions (except Fe2+ and SO42-) exceeded the WHO (2006) and NAFDAC recommended limits for drinking water in some places. The dominant cation and anion in the groundwater are magnesium and chloride respectively. The water types are Mg-Cl, Ca-Mg-SO4 and Na- K waters. \r\nThe high concentration of sodium and chloride in the water samples from some places in the study area could be from contamination by saline effluents or leachates from waste dumps. The relative high concentration of nitrate in the study area could be as a result of pollution from septic tanks. \r\nWaste dumps of serious environmental concern were observed at Fire Brigade, Tudun Nupewa, Tudun Wada, Hayin Banki, Ungwan Dossa, and Kawo. Kaduna River around the factories at Kakuri and downstream of River Kaduna are polluted with industrial waste. \r\nIt is recommended that the factories located in Kaduna South should process their industrial wastes before discharging them into the river. In addition, the water from hand-dug wells in the area should be treated before drinking.\r\n

The effects of waste dumps on the groundwater supply in Kano and the environs are being investigated. Water samples were collected from the ubiquitous hand-dug wells which form the major source of water supply to the Kano populace, as 96 of the samples were analyzed for their cation and anion contents. \r\n\r\nThe chemical analyses revealed the presence of Ca2+, Mg2+, Na+, K+, Fe2+ , etc. as cations while anions include: HCO3-, Cl-, SO42-, NO3-. The chemical analyses also showed that the groundwater is polluted by leachates from the waste dumps because the values of total dissolved solids, conductivity and salinity were very high in wells near the dumpsites. For instance, at the Court Road dumpsite in Kano metropolis, the total dissolved solids in the wells near it were 983mg/l, conductivity 2000 microsiemens and pH 7.8, while at Yanlemu dumpsite, the total dissolved solids was 1240mg/l conductivity 2520 microsiemens and a high chlorine content of 16.2mg/l. The pH ranged from 5.57 to 7.60 though with most values between 6.0-7.0.\r\n\r\nMicrobial analyses showed that the wells are polluted by micro-organisms like Escherichia coli that could cause epidemic of cholera and such gastrointestinal diseases.\r\n\r\nThe Vertical Electrical Sounding (VES) was used to complement the hydrogeological mapping. A total of 24 VES points were chosen based on different lithologies. It was deduced by the VES that the depths of the topsoil (mainly laterites) to the weathered basement, which is the aquifer, varied from 0.4 - 13.1metres. \r\n\r\n\r\nSieve analysis was performed to further complement the study of the groundwater infiltration. The silty, medium and coarse gravels permit passage of rainwater into the vadose zones and thence to the water-table.\r\n\r\nThe state government could reduce reliance on wells especially for domestic use by providing adequate tap water to the populace. Such will increase the quality of life and improve the economy of the area.\r\n

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

Effect of rock-water interactions in Calabar area

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