The selection of environmentally secure landfill sites in geologically complex crystalline basement terrains remains a critical challenge in developing nations, where inadequate siting leads to pervasive groundwater contamination. This study presents a rigorous hydrogeophysical assessment framework to evaluate landfill suitability in Ede, Southwestern Nigeria, an area underlain by Precambrian Basement Complex rocks. Sixty-two (62) Vertical Electrical Sounding (VES) stations were deployed to characterize the subsurface, deriving key parameters including overburden thickness, weathered layer resistivity, longitudinal conductance, transmissivity and hydraulic conductivity. These parameters were spatially interpolated using GIS to generate thematic maps and a composite suitability model. Results from the study delineated a multi-layered subsurface architecture, identifying zones where a combination of thick overburden (>20 m), low weathered layer resistivity (<150 Ωm, indicating clay-rich content), high longitudinal conductance (>0.7 mhos), low transmissivity (< 0.3 m2/day) and low hydraulic conductivity (<0.02 m/day) provides optimal natural containment against leachate migration. The integrative analysis reveals that only 9.5% of the study area is classified as 'Most Suitable,' while 36.5% and 54% are deemed 'Moderately Suitable' and 'Least Suitable,' respectively. This finding highlights the significant hydrogeological constraints within the basement complex and the risk of relying solely on surface observations. This research demonstrates the critical efficacy of integrating geophysical methods with spatial analysis for sustainable environmental planning. It provides a framework that may be adapted for landfill siting in similar crystalline basement terrains, offering a basis for safeguarding groundwater resources. The approach contributes to environmental science, urban development, and aligns with multiple Sustainable Development Goals (SDGs), particularly SDGs 6, 11, 14 and 15.

This research utilized various data types, including remote sensing (RS), aeromagnetic (AM), vertical electrical sounding (VES), and hydrogeological (HG) information, to create a groundwater potential map (GPM) of the Ogbomoso region in southwestern Nigeria. The lineaments obtained from the RS and AM results were merged to produce the lineament density (LD) map of the Ogbomoso area. One hundred and sixty-five VES data were collected for this study. The Ogbomoso area has a distinct geoelectric sequence that consists of various layers. These include the topsoil, weathered/saprolite, saprock, fractured basement, and fresh basement rock. Eight groundwater conditioning factors (GwCFs) were considered to ensure an accurate assessment of the groundwater potential (GP) in the Ogbomoso area. Stepwise weight assessment ratio analysis (SWARA), a multicriteria decision analysis (MCDA) technique, was used to assign weights to each GwCFs. The given weight was normalized, and a coefficient of coherence was established. SWARA helped characterize GP in the Ogbomoso area into different categories. It was discovered that there is a 0.63-degree correlation between well locations and GPM produced for the Ogbomoso area. This confirms that the SWARA modeling technique is reliable for predicting groundwater potential in any typical basement complex terrain worldwide.

Mineral exploration involves the acquisition of economic extractive mineral deposits, in which the relevance of geophysical methods cannot be overemphasized for its fast, cost effective and non-destructive ways of understanding the subsurface conditions. In this work, signature reference from electromagnetic, electrical resistivity, and induced polarization geophysical methods assisted in unraveling the presence of a polymineralic deposit, as well as determining the economic potential of the deposit within investigated hydrothermally altered zones in Ilesha Schist Belt, Southwestern Nigeria,. The electromagnetic method delineated anomalies related to mineralized zones of weathering, fracturing, and dyke-like structures. Electrical resistivity (ER) and induced polarization (IP) methods highlighted areas with fractures/faults, mineralized weathered layer, and disseminated sulfide deposits between the depth of 5 and 60 m. Resistivity and chargeability variations (33.8-529 omega m and 3.88-12.2 msec respectively) of the mineralized structures and formations assisted in delineating probable presence of galena, pyrite and chalcopyrite sulfide ores. A validation study using borehole data revealed mineralized host rock at the depth of 25.3 m, with the presence of disseminated metallic sulfide in quartz veins within the depth of 27.8 to 40.8 m. Similarly, validation studies using geochemical analysis shows pathfinder elements of sulfide minerals; iron (Fe), sulphur (S), copper (Cu), lead (Pb), and antimony (Sb); confirming the presence of galena, pyrite, and chalcopyrite deposits. Both validation methods confirmed the reliability of geophysical signature in identifying polymineralic deposits within the investigated area. This research has however revealed more areas, identified as exploitable polymineralic deposits, to enhance mining operations in the study area.

This study modeled geophysical derived parameters and multi-critically synthesized their themes based on geospatial and analytical hierarchy processes (AHP) approaches for groundwater potentiality prediction mapping. These methodologies were investigated in a typical hard rock geologic terrain, southwestern, Nigeria. Considering the spatially acquired 96 vertical electrical sounding (VES) data in the area, geoelectric sections revealing five subsurface layers including the topsoil, laterite, weathered layer, fractured basement and fresh basement rock were produced mindful of the 2-D resistivity structure subsurface imaging data interpreted results. The correlative results of the 2-D resistivity structure images and VES data interpretation results delineated major low resistivity vertical discontinuity typical of fractured zones characterized with width range of 25–40 m, while the depth vary from about 40 to > 60 m. Themes of groundwater potential conditioning factors (GPCFs), namely: regolith, bedrock relief, hydraulic head, coefficient of anisotropy, aquifer resistivity and aquifer thickness were prepared from the re-analyzed hydrogeological and geophysical data. The produced themes were appropriately weighted in the context of AHP data mining technique. The groundwater potential prediction index (GPPI) mathematical modeling equation for the area was established via applying the weight linear average algorithm involving the AHP weightage results. The synthesized results of the applied GPPI model equation on the GPCFs’ hydrogeologic themes give GPPI values in the range 1.59–3.65 for the study area. The geospatial modeling of the GPPI estimated values result produced groundwater potential prediction index map for the area. The produced GPPI model map zoned the area into low (1.59–2.30), medium (2.30–2.61), medium–high (2.61–3.02) and high (3.02–3.65) groundwater potential classes. The area analysis of the GPPI map indicates that more than 70% of the study area has ‘low to medium groundwater potential. The GPPI map result verification using reacting operating characteristics technique results gave 86% and 81% success and prediction rates, respectively. The findings of this study are useful to water managers and decision-makers for locating appropriate positions of new productive wells in the study area and other areas with similar geologic settings.

Gold occurrences have been reported in Alagbede, southwestern Nigeria, but a mineral potential map (MPM) to guide academics and investors in the area is still needed. As a result, geophysical methods (aeromagnetics and aero-radiometry) have been used to assess the potential for gold minerals in the area. Several enhancement filters, such as reduction to the equator, upward continuation, analytical signal, second vertical derivative, and power spectrum analysis, were applied to the aeromagnetic data to understand the subsurface geology better. The enhancement filters applied to airborne radiometry data are K/eTh, ternary color composite, F parameter, and deviation from the ideal K values (Kd). Geophysical data analysis was used for structural mapping and geological reconstruction, while aero-radiometric data was used for hydrothermal alteration mapping. The primary trend observed in the area’s magnetically inferred structural framework map is NE-SW, while a few are in the NW–SE and E-W trends. These observed trends show that the study area suffered at least three deformation episodes. Geological evidence of gold mineralization, such as favorable lithology, geological structure, and hydrothermal alterations, has been fused to produce a reliable MPM of the area. The geographical location of the existing mineral sites in the investigated area agrees with the geological structures and the MPM produced there. Thus, the systematic approach adopted in this study can be extended to other supracrustal belts of a typical Precambrian basement complex worldwide to ensure the reliability of orogenic gold mapping and resource management.

Airborne magnetic and radiometry data sets over potential gold mineralisation associated with mesothermal alteration zones in the western Ilesha schist belt, Southwestern Nigeria, were interpreted. This was done to provide information on possible extent of geologic transformations that accompanied gold mineralisation in the area. Interpreted gamma spectrometric data were successfully used in delineating zones of hydrothermal alteration associated with potassium K enrichment as the target for gold deposits. The geological structural features that host the ore deposits were identified as lineament represented by lithological contacts and faults/fractures that were successfully exacted from the airborne magnetic data. The potassium deviation (KD) map was computed to enhance the potassium signature of rocks in the area of study. Thus, the KD map represents real potassium distribution across the study area emanated from hydrothermal alteration where hydrothermalised zones were displayed by high KD values. First vertical derivative (FVD) and total horizontal gradient (THG) maps were used to delineate lineaments. These lineaments were connected using the frequency rose diagram with two main lineament set,; major and minor lineaments observed. The 3D Euler deconvolution (EUD) method was also applied on the THG map to locate and evaluate depths to subsurface structures. The best 3D EUD solution for dykes and contacts modelled using the Structural Index of zero (S.I = 0) was used to estimate the depth to these anomaly sources at 300 to 700 m in the study area. The EUD results also revealed several subsurface structures which were hidden in the existing geological map of the study area. A prospective mineralisation map was produced from the synthesis of both magnetic lineaments and alteration zones maps derived for the study area, showing the areas of probable high mineral resources. Strong relationships were observed between the mapped hydrothermal altered zoneseologic structures and superimpose known gold mining pits.

An Integrated geophysical and geotechnical subsoil characterization of parts of the new stadium complex, Akure, southwestern Nigeria had been carried out with a view to characterize the subsoil materials for stability of proposed engineering foundation. Five (5) magnetic and three (3) dipole-dipole profiling were carried out at station separation of 10 m along the traverses. Twenty one (21) Vertical Electrical Sounding (VES) measurements were made at selected locations along the traverses. A total of five (5) soil samples were collected from a dug pit at a depth of 1.0 m for laboratory analysis. The magnetic profiles delineated characteristic one to two negative peak amplitude anomalies that are typical of thin dipping dyke models (suspected to be fractures, shear zones, faults or geological contacts) along Traverses 1-5. The 2-D geomagnetic section delineated overburden thicknesses ranging from 5 – 15 m along the Traverses. The subsurface geologic units delineated by the geoelectric sections and the 2-D resistivity images consisting of the topsoil, weathered layer, partly weathered/fractured basement and fresh bedrock. Part of the topsoil and the weathered layer are characterized by low resistivity values suggestive of the presence of clay and or weak geomaterials at a depth range of 1 – 4 m within which civil engineering foundation are usually placed. These zones and the fractured/fault zones delineated by the magnetic methods constitute weak geomaterials that are considered to be inimical to civil engineering structures within the study area. Results of geotechnical analysis of soil samples adjudged plasticity indices of samples A, C and D to be of high index and were characterized by high plasticity/compressibility and consequently of low engineering competence. Samples B and E were classified as low-medium plasticity/compressibility, and are rated moderate–high engineering competence. However, it was observed that soil with higher liquid limits or plasticity index have lower electrical resistivity values and hence were adjudged low in engineering foundation competence. Based on the analysis of the results obtained from this study, the engineering foundation suitability of the soil were generally classified as good (B and E), fair (D) and poor (A and C). It can therefore be concluded that the subsoil in the investigated area are generally of low to high civil engineering competence. Keywords: Geophysical; Geotechnical; Subsoil; Competence; Characterization; Foundation, Stability. DOI: 10.7176/JEES/10-6-08 Publication date: June 30 th 2020

The salineation of freshwater aquifer units with the view of assessing groundwater quality in parts of Lagos State areas has been investigated in this study. The objectives task was achieved via exploring the potential of borehole geophysical method. The obtained suites of geophysical well logs covering the west – east and south – northeast directions were subjected to lithostratigraphic correlation analysis using the Petrel software. Based on the analysed results, five aquifer units characterized the study area with thickness ranging from > 5 m to 205 m were delineated. Further analysis established that saline water aquifer, brackish water sand, fresh water sand with resistivity values in the range of 0 – 60 ohm-m, 60 – 80 ohm-m and > 80 ohm-m, respectively at the depths of 10 – 165 m were delineated using the resistivity well log tool along the lithostratigraphic sequence. It was evidenced from the analysis that saline water often occurred greatly at depth of 10 – 160 m and the depth at which fresh water can occur in the area is greater than 200 m along the east – west and 0 – 200 m in the southwest – northeast sections. This study concludes that borehole geophysical wireline logs can be effectively relied upon in the delineation of aquifer units and assessment of groundwater quality in the investigated area. Keywords: Geophysical, Well Log Analysis, Aquifer, Salt-water Intrusion, Lagos State.

A geoelectric investigation, involving 1-D Vertical Electrical Sounding (VES) with the Schlumberger array and 2- D Electrical Imaging with the dipole-dipole array, was carried out at a site proposed for an airport in Ebonyi State. This was with a view to generating near and subsurface images required for the assessment of the suitability of the site for civil engineering construction works. Fifty six (56) VES stations were occupied along eight (8) traverses while the dipole-dipole profiling was carried out along segments of three of the traverses. The VES curves were quantitatively interpreted and the results were used for the generation of geoelectric sections and isopach map of the lateritic layer. Four subsurface layers were delineated. These include the topsoil (lateritic in most places), lateritic shale, shale/clay and siltstone. The topsoil resistivity values varied from 24-5898 Ωm while the thicknesses ranged from 0.7 - 4.6 m. The lateritic shale second layer resistivities and thicknesses were 101-473 Ωm and 1.6 - 8.3 m respectively. The clay/shale third layer showed thicknesses and resistivity values of 3.6 – 108.3 m and 1 – 98 Ωm respectively. The fourth layer was siltstone with resistivity values ranging from 53 -3170 Ωm. The 2-D resistivity structures delineated two subsurface layers: a merged topsoil/lateritic shale top layer and the underlying clay/shale layer. No subsurface geologic structure was delineated. The high resistivity lateritic topsoil/lateritic shale and the basal siltstone constituted the two competent layers while the low resistivity shale/clay, the incompetent horizon. The upper competent lateritic layer could host light-medium weight civil engineering structures while heavy structures would need to be anchored on friction piles. Keywords : Geoelectric Investigation, Subsurface Sequence, Subsoil Competence, Structure Foundation.

Erosion index map of Akure Metropolis was developed using an integrated remotely sensed, geological and soil data. This was with a view to classifying the metropolis into different erosion risk zones. Administrative and topographic maps, geologic and soil maps, Landsat ETM+, Aster DEM and thirty two (32) erosion types data were acquired. Landsat ETM+ was pre-processed for geometric correction, haze reduction and re-sampling. Optimum index factor and covariance analysis were carried out in order to determine the least correlated bands and these bands were subjected to convolution filters, texture analysis at 3X3 window size, histogram equalization, de-correlation stretch, principal component analysis (PCA) and the Aster DEM to topographic analysis such as sink fill and shielded relief to generate slope map and lineament map. All the derived maps including the soil map were reclassified and given risk values according to their order of degree of contribution to either accelerate or decelerate soil erosion. Using weighted index overlay raster tool in ArcGIS software, all thematic maps were captured in GIS environment to produce a composite erosion index map of the study area. Existing erosion type data were used to establish the reliability of the erosion index map. The erosion index map classified the Akure Metropolis into three zones – very low risk (57.5%); low risk (33.9%) and moderate risk (8.6%). Most parts (91.4%) of the metropolis fell within the very low to low risk zones with tendency for sheet/reel erosional features. Areas with moderate risk with tendency for gully erosion were majorly located on the high slope region.

Geophysical and hydrochemical investigations have been used to map pollution in the area around a dumpsite in Ilara-Mokin, southwestern Nigeria. Three (3) Very Low Frequency Electromagnetic (VLF-EM) profiling, dipoledipole 2-D electrical imaging and fourteen (14) Vertical Electrical Soundings (VES) were carried out in the study area. Four (4) water samples from hand dug wells and two (2) surface water samples were collected around the dumpsite for physical and chemical analyses. The inverted 2-D resistivity structures and the geoelectric sections delineated four subsurface geoelectric units. These are the topsoil, weathered layer, partly weathered/fractured basement and the fresh basement bedrock. Within the premises of the dumpsite, the topsoil, the weathered layer, and the partly weathered/fractured basement are characterized by relatively low layer resistivity values of 6 – 50 ohm-m suspected to be due to conductive leachate from the dumpsite. The conductive zones were also identified by the VLF-EM 2-D subsurface image. The physical and chemical characteristics of the sampled waters include: electrical conductivity of 850 – 1000 µmho/m; pH value of 6.2 – 7.3; total hardness values of 29 – 47 mg/l; sulphate concentration of 80 – 90 mg/l and nitrate concentration of non detectable – 10 mg/l. The relatively high electrical conductivity may be indicative of surface and groundwater pollution. The polluted zone has a depth extent of about 2.5 – > 15 m and lateral extent of about 140 m west and up to 50 m south of the dumpsite.

Hydrochemical analysis was carried out on surface and groundwater samples collected from Akure metropolis with a view to determining their quality. Hydrochemical data on groundwater samples from fifty six (56) boreholes were sourced from the Ondo State Water Corporation. Twenty five (25) surface water samples from streams and rivers in the study area were collected and analyzed using standard analytical techniques. The analyzed physical parameters include colour, odour, turbidity, conductivity and chemical properties such as pH, dissolved solid, hardness, cations, anions and heavy metals. All the groundwater samples were colourless, odourless and tasteless. Some surface water samples were coloured and turbid in appearance while some had objectionable odour. Although the NO 3 - concentration levels in both surface and groundwater samples were generally below the WHO threshold value of 10 mgl -1 , relatively high concentration range (2.5-6.0 mgl -1 ) was recorded within the city centre indicating some level of pollution from cumulative anthropogenetic activities. Only few surface water samples contain Pb while Mn was identified in some surface and groundwater samples. The elevated Pb concentration levels (0.41-3.41 mgl -1 ) and relatively high Mn concentration levels (up to 2.18 mgl -1 ) (both much higher than the WHO and NIS thresholds) in some surface water samples was an indication of heavy metal pollution. Conductivity values of the groundwater samples generally ranged from 42.0 – 1400.0 µScm -1 . Only surface water sample 17 was moderately saline while other surface water samples were of freshwater type. Based on TDS values, all the groundwater and surface water samples were of freshwater type (TDS < 1000 mgl -1 ). Keywords: Physico - chemical Analysis, Surface/Groundwater, Quality, Akure Metropolis.

An integration of remote sensing, soil type, geological, geoelectrical, hydrogeological and geotechnical data was carried out in a GIS environment with a view to developing a constraint map for the location of landfill (waste disposal) site(s) in Akure, Metropolis.. Geomorphological features identified from satellite images include o residual hills, pediments, pediplain and etchplain . The slope (gradient) map displays surface gradients of 0 - 2.5 o along river channels while areas with moderate and high relief have surface gradients of 2.5 - 6.35 and 6.35 - o 29.53 o respectively. Satellite-imagery-delineated lineaments predominantly trend NNW-SSE, ENE-WSW and NNE-SSW with subsidiary NW-SE and W-E trends that are typical of the Basement Complex region of Nigeria. The engineering geotechnical results show that charnockite-derived soils are very clayey and silty in nature (with % clay content > 18%) with low permeability, and are therefore more suitable for waste disposal (landfill) site than the sandy and gravely (with low % clay content < 7%) granite and migmatite gneiss-derived soils. VESderived topsoil and weathered layer are characterized by relatively low layer resistivity values (< 100 ohm-m) over basic charnockitic rocks. The synthesis of the above results enables the classification of the Akure metropolis into three landfill suitability zones – unsuitable (28.6%); moderately suitable (40.4%), and suitable (13%) for waste disposal (landfill) sitting. Keywords : GIS, Remote Sensing, Geoelectric, Geotechnical, Constrain Map, Landfill Site.

Hydro-geophysical investigation for deep fractured columns involving the Very Low Frequency Electromagnetic (VLF-EM) and the electrical resistivity methods has been carried out within the Federal Housing Estate Akure, Southwestern Nigeria. This was with a view to assessing the groundwater potential of the Estate. Four (4) VLF-EM and Horizontal Profiling (HP) traverses were established. Eighteen (18) Vertical Electrical Soundings (VES) were conducted at the investigated site. The VLF-EM data were presented as profiles and 2-D images. Horizontal Profiling (HP) data were also presented as profiles while the VES data were presented as geoelectric sections. The VLF-EM profiles and 2-D images identified conductive zones (suspected to be basement structures) which were confirmed by the subsurface geoelectric sections developed from the interpretation results of the Vertical Electrical Sounding (VES). The geoelectric sections delineated five subsurface geologic layers. These include the top soil, weathered layer, fresh basement, fractured basement and the fresh basement bedrock. The fractured basement constitutes the main aquifer unit within the study area. The weathered layer is generally thin and clayey. The confined fractured basement columns (Olorunfemi and Fasuyi, 1993) are characterized by relatively low resistivity values (82 - 602 ohm-m) and moderate to significant thickness (20.4 - 65.6 m). The relatively low fractured basement resistivity could indicate enhanced permeability due to significantly fractured density and tendency for moderate groundwater potential and yield. This study demonstrates the effectiveness of integrated geophysical investigation in groundwater potential assessment in a typical basement complex environment.

Data from dc resistivity depth sounding and hydrogeologic measurements from Odigbo, Nigeria, were incorporated to delineate the groundwater prospect zones in the area. The area is underlain by the basement complex rocks of southwestern Nigeria, and characterised by biotite-gneiss and quartzite lithologies. The hydrogeologic data acquisition involved determination of depths (of wells) and static water levels which enabled determination of thickness of vadose and phreatic zones in 45 existing wells. The dc resistivity measurements involved Schlumberger depth soundings in 61 locations. The interpretation of the sounding data enabled the delineation of geoelectric sequence across the area. Depth to water table (groundwater head) ranges from 2.3 to 9.6 m while the thickness of the phreatic zone, an approximation of water column thickness, varies from 0.1 to 3.0 m, with the thickness in the range of 2.1 to 3 m constituting about 9%, and occurring in the central segment of the study area. The regolith overlying the basement rock constitutes the main water-bearing layer, since the resistivity parameters of the bedrock across the area do not suggest significant fractures or faults. The northwest – southeast and north – south trend of the aquifer unit within the regolith, with resistivity below 210 Ω-m, and constituting about 62% of the area, are considered the groundwater prospect zones. Based on aquifer thickness parameters, the groundwater prospect zones have been classified into low ( 40 m) respectively. 46% falls within the medium/high groundwater prospect rating while 54% falls within the low rating. The maps derived from the above are considered reliable prospect guides for groundwater developers in the area.

Department of Applied Geophysics, Federal University of Technology, Akure (FUTA) Corresponding Author: S. Bayode ___________________________________________________________________________ Abstract An integrated geophysical investigation involving the Electromagnetic (EM) profiling, Dipole-Dipole profiling and the geoelectric depth sounding have been conducted as post-foundation study at the premises of the 2500 capacity auditorium building, Federal University of Technology, Akure, Nigeria. The area is underlain by the Precambrian basement complex rocks. Three VLF-EM and Dipole Dipole profiles plus fifteen Vertical Electrical Sounding (VES) stations were established in the study area. Measurements were taken at 5 m intervals along the three Traverses. The depth soundings (three-five) conducted along each of the profiles was subsequently correlated with the EM and Dipole Dipole data interpretation. An interpretation of the EM anomalies identified conductive zones, suspected to be fractures/faults along three traverses. The geoelectric sections and the inverted 2-D resistivity structures delineated four subsurface geoelectric layers which include the topsoil, weathered layer, weathered/fractured basement and the resistive basement bedrock. The fractured/fresh basement constitutes the basement bedrock in the 2-D resistivity structure. This study revealed that the subsurface geologic materials underlying the investigated building is characterized by the presence of heterogeneous near surface geomaterials, and an uneven basement topography at shallow depths of < 1 – 4 m were foundations are usually placed. These, coupled with the mapped vertical discontinuity within the basement bedrock, designated as F1 (50 – 60 m wide), F2 and F3 (30 – 35 m wide) are classified as weak zones (Fractures/faults). These features constitute zone of geotechnical weakness which may precipitate subsidencerelated failure and eventual collapse of the foundation of the building. This study advocates pre-construction engineering survey at any civil engineering site since it can reliably evaluate the geotechnical competence of the subsurface geomaterials and compliment routine pre-construction engineering geotechnical investigation. __________________________________________________________________________________________

Geophysical, hydrogeological, and hydrochemical investigations have been used to assess the impact on soil and groundwater of some ancient dumpsites in Akure Metropolis. One hundred and seventy one (171) Vertical Electrical Sounding (VES) and dipole – dipole profiling along six (6) profiles were carried out. Seventy (70) water samples were collected from hand dug wells for chemical analysis within a radius of about 600 m from the centre of the ancient dumpsites. The geoelectric sections and the inverted 2-D resistivity structures delineate three subsurface geological units consisting of the topsoil, weathered layer and the fractured/fresh basement rock. The weathered layer constitutes the main aquifer unit. The 2-D resistivity structures show that within the premises of the dumpsites, the topsoil and the weathered basement aquifer unit are characterized by relatively low layer resistivity values of 250 mg/l and nitrate concentration of > 10 mg/l which confirm groundwater pollution. It can be concluded that the soils and the groundwater in the areas around the investigated dumpsites have been polluted. The polluted zone has a depth extent of about 2.5 – >7.5 m and lateral extent of about 250 m north and up to 500 m south of the dumpsites.