Hydrogeochemical Assessment of Groundwater in Epe (Nigeria) for Drinking and Irrigation Purposes
Main Article Content
Abstract
Groundwater sustainability demands routine quality monitoring. This study assessed the hydrogeochemistry of groundwater in Epe, Lagos State, to evaluate its suitability for drinking and irrigation. Fifty well-water samples from eight communities were analyzed for pH and major ions. Results showed that parameters complied with regulatory standards in most locations except magnesium (65.70±23.50 - 96.00±19.68 mg/L) which consistently exceeded the Nigerian Standard for Drinking Water Quality of 20 mg/L. Dietary intake of essential elements was generally negligible, though magnesium levels in Poka exceeded recommended daily allowance for infants (0-6 months). The Water Quality Index (40.41 - 128.49) classified the water as 8% “excellent,” 76% "good," and 16% "poor" while the Pollution Index of Groundwater (0.39 - 0.85) ranked all samples as having insignificant pollution. Though, majority of the irrigation indices indicated suitability for irrigation; Permeability Index (<25% in 88% of samples), Magnesium Adsorption Ratio (>50% in 86% samples) and Corrosivity Ratio (>1 in 50% samples) presented risks to long-term soil permeability and metallic water transport pipes. The ionic dominance was Mg²⁺>Ca²⁺>Na⁺>K⁺ and HCO₃⁻>SO₄²⁻>Cl⁻. Geochemical diagrams (Piper, Chadha and Schoeller diagrams) revealed a Ca-Mg-HCO₃ facies, attributed to mixed carbonate-silicate weathering (Gaillardet diagram), rock-water interaction (Gibb’s diagram) and ion exchange (CAI, CAII), with the Hydrochemical Facies Evolution Diagram indicating mixed facies. Principal Component Analysis identified bicarbonate (PC1: 57.33%), calcium (PC2: 17.35%), sulphate (PC3: 15.94%) and magnesium (PC4: 8.38%) as the primary factors controlling water quality. The study recommends water treatment, the use of corrosion-resistant pipes, and sustained monitoring to safeguard this resource.
Article Details
Copyright (c) 2026 Benjamin Onozeyi Dimowo, Adewole Michael Gbadebo, Kudirat Akorede Otubu, Oluwajumilo Oluwadara Gbadebo (Author)
This work is licensed under a Creative Commons Attribution 4.0 International License.
Adewole Michael Gbadebo, Department of Bioscience, University of East London, London, United Kingdom.
Professor of Environmental Geology/Geochemistry, Department of Geology
Abdu-Raheem, Y. A., Talabi, A. O., Afolagboye, L. O., & Oyebamiji, A. O. (2024). Hydrogeochemical and bacteriological assessments of groundwater quality in Iworoko, Southwestern Nigeria. Arabian Journal of Geosciences, 17(3), 78. DOI: https://doi.org/10.1007/s12517-024-11875-x
Adamu, A. Y., Nigussie, A. B., & Amognehegn, A. E. (2024). Hydrogeochemical Study and Geospatial Analysis of Water Quality Using GIS based Water Index and Multivariate Statistics in Kombolcha City, Ethiopia. Water, Air, & Soil Pollution, 235(10), 637. DOI: https://doi.org/10.1007/s11270-024-07438-1
Adimalla, N. (2021). Application of the entropy weighted water quality index (EWQI) and the pollution index of groundwater (PIG) to assess groundwater quality for drinking purposes: A case study in a rural area of Telangana State, India. Archives of Environmental Contamination and Toxicology, 80: 31–40. https://doi.org/10.1007/s00244-020-00800-4 DOI: https://doi.org/10.1007/s00244-020-00800-4
Agidi, B. M., Akakuru O. C., Aigbadon, G. O. Schoeneich, K., Isreal, H., Ofoh, I. Joy, N. and Esomonu, I. (2022). Water quality index, hydrogeochemical facies and pollution indexof groundwater around Middle Benue Trough, Nigeria. International Journal of Energy and Water Resources, 8 (1): 1-20 DOI: https://doi.org/10.1007/s42108-022-00187-z
Agunbiade, M., Rajabifard, A., & Bennett, R. (2013). Modes of housing production in developing countries: The contemporary role of land, labour, and capital in Lagos, Nigeria. Journal of Housing and the Built Environment, 28(2), 363–379. DOI: https://doi.org/10.1007/s10901-012-9303-8
Akakuru, O. C., Eze, C. U., Okeke, O. C., Opara, A. I., Usman, A. O., Iheme, O., Ibeneme, S. I. & Iwuoha, P. O. (2022). Hydrogeochemical evolution, water quality indices, irrigation suitability and pollution index of groundwater (PIG) around Eastern Niger Delta, Nigeria. International Journal of Energy and Water Resources, 6(3): 389-411. DOI: https://doi.org/10.1007/s42108-021-00162-0
Akinmoyeje, T. (2025). Pupils Learn Under Trees 4 Years After Lagos Spent N280m on Epe School. Retrieved 11th October 2025 from https://fij.ng/article/pupils-learn-under-trees-4-years-after-lagos-spent-n280m-on-epe-school/
Akintude, O. A. (2025). Delineation Effect of Subsurface Leachate Plume Contamination on the Groundwater using Geo-Electrical and Geo-Chemical Techniques: Case Study of Epe Dumpsite, Temu-Orisha, Epe, Lagos State, Nigeria. The Transactions of the Nigerian Association of Mathematical Physics, 21, 93-109.
Al-Aizari, H. S., Aslaou, F., Al-Aizari, A. R., Al-Odayni, A. B., & Al-Aizari, A. J. M. (2023). Evaluation of groundwater quality and contamination using the groundwater pollution index (GPI), nitrate pollution index (NPI), and GIS. Water, 15(20), 3701. DOI: https://doi.org/10.3390/w15203701
Al-Mashreki, M. H., Eid, M. H., Saeed, O., Székács, A., Szűcs, P., Gad, M., Abukhadra M. R., AlHammadi, A. A., Alrakhami, M. S., Alshabibi, M. A., Elsayed, S., Khadr, M., Farouk, M. & Ramadan, H. S. (2023). Integration of geochemical modeling, multivariate analysis, and irrigation indices for assessing groundwater quality in the Al-Jawf Basin, Yemen. Water, 15(8), 1496. DOI: https://doi.org/10.3390/w15081496
Ali, S., Verma, S., Agarwal, M. B., Islam, R., Mehrotra, M., Deolia, R. K., Kumar, J., Singh, S., Mohammadi, A. A., Raj, D. & Fattahi, M. (2024). Groundwater quality assessment using water quality index and principal component analysis in the Achnera block, Agra district, Uttar Pradesh, Northern India. Scientific Reports, 14(1), 5381. DOI: https://doi.org/10.1038/s41598-024-56056-8
Alogayell, H. M., El-Bana, E. M. M., & Abdelfattah, M. (2023). Groundwater quality and suitability assessment for irrigation using hydrogeochemical characteristics and pollution indices: A case study of North Al-Quwayiyah Governorate, Central Saudi Arabia. Water, 15(18), 3321. DOI: https://doi.org/10.3390/w15183321
Amadi, A. N., Umoru, T. A., Umeugochukwu, O. P., Nwankwoala, H. O., Sule, T. U. N., Oguntade, A. S., Ibrahim, H. A. and Hussaini, S. U. (2020). Suitability of Groundwater in Auchi and Its Environs for Irrigation Purposes. The Pacific Journal of Science and Technology, 21 (2): 379 - 387.
American Public Health Association, American Water Works Association, Water Environment Federation (APHA - AWWA - WEF), (2023). Standard Methods for Examination of Water and Wastewater. In: Lipps WC, Braun-Howland EB, Baxter TF eds., 24th Edition, Washington DC: APHA Press
Anaga, S.O., Noble-Okereke, H., Unaeze, C.H., Yusuf, H.O. (2023). Modeling of Groundwater Quality Near a Dumpsite Using Principal Component Analysis of Physico-Chemical Parameters. Environmental Studies Journal, 2 (1): 73-89. DOI: 10.36108/esj/3202.20.0160 DOI: https://doi.org/10.36108/esj/3202.20.0160
Awad, E.S., Imran, N.S., Albayati, M.M., Snegirev, V., Sabirova, T.M., Tretyakova, N.A., Alsalhy, Q.F., Al-Furaiji, M.H., Salih, I.K., Majdi, H.S. (2022) Groundwater Hydrogeochemical and Quality Appraisal for Agriculture Irrigation in Greenbelt Area, Iraq. Environments, 9: 43 DOI: https://doi.org/10.3390/environments9040043
Awomeso, J. A., Ahmad, S. M., & Taiwo, A. M. (2020). Multivariate assessment of groundwater quality in the basement rocks of Osun State, Southwest, Nigeria. Environmental Earth Sciences, 79(5), 108. DOI: https://doi.org/10.1007/s12665-020-8858-z
Badmus, G. O., Akinyemi, O. D., Gbadebo, A. M., & Oyedepo, J. A. (2020). Hydrochemical analysis of groundwater quality along the coastal aquifers in part of Ogun Waterside, Ogun State, southwestern Nigeria. Heliyon, 6(12). DOI: https://doi.org/10.1016/j.heliyon.2020.e05661
Balogun, I. I., Akoteyon, I. S., & Soneye, A. S. O. (2019). Season-Induced Variation in Water Table Depth and Selected Chemical Parameters of Groundwater in Lagos Coastal Plain Sand Aquifer, Nigeria. Journal of Applied Sciences & Environmental Management, 23(8). DOI: https://doi.org/10.4314/jasem.v23i8.9
Benamina, B., Bentabet, A., Azzaz, H., Dahmani, A., & Hamimed, A. (2025). Groundwater quality assessment using groundwater pollution index (PIG) and non-carcinogenic human health risk assessment of fluoride and nitrate (HHR) in a semi-arid region of Mascara (northwestern of Algeria). Journal of Degraded and Mining Lands Management, 12(3): 7705-7721. DOI: https://doi.org/10.15243/jdmlm.2025.123.7705
Davis, S. N. and Wiest, D. (1996). Hydrogeology. New York, John Wiley & Sons. 463 pp.
Dheeraj, V. P., Singh, C. S., Alam, A., & Sonkar, A. K. (2025). Hydrogeochemical quality investigation of groundwater resource using multivariate statistical methods, water quality indices (WQIs), and health risk assessment in Korba Coalfield Region, India. Stochastic Environmental Research and Risk Assessment, 39(3), 937-958. DOI: https://doi.org/10.1007/s00477-024-02895-w
Doneen, L. D. (1964). Notes on water Quality in Agriculture. Department of Water Science and Engineering, University of California: Davis, CA, USA
Duc, H. D., Dan, N. H., Binh, N. C., & Oanh, N. T. (2025). Evaluation of Groundwater Quality and Effects of Exploitation on Static Groundwater Levels in Dong Thap Province, Viet Nam. Water Resources, 52(5), 1061-1082. DOI: https://doi.org/10.1134/S0097807824606721
Eaton, F. M. (1950). Signifcance of carbonate in irrigation water. Soil Science, 69 (2): 123–133 DOI: https://doi.org/10.1097/00010694-195002000-00004
Edet, A. (2017). Hydrogeology and groundwater evaluation of a shallow coastal aquifer, southern Akwa Ibom State (Nigeria). Applied Water Science, 7: 2397–2412 DOI: https://doi.org/10.1007/s13201-016-0432-1
Egbueri, J. C., Unigwe, C. O., Omeka, M. E., & Ayejoto, D. A. (2021). Urban groundwater quality assessment using pollution indicators and multivariate statistical tools: a case study in southeast Nigeria. International Journal of Environmental Analytical Chemistry, 103(14), 3324–3350. https://doi.org/10.1080/03067319.2021.1907359 DOI: https://doi.org/10.1080/03067319.2021.1907359
Eyankware, M. O., Akakuru, O. C., Ulakpa, R. O. E. and Eyankware, O. E. (2021). Sustainable management and characterization of groundwater resource in coastal aquifer of Niger delta basin Nigeria. Sustainable Water Resources Management, 7 (58): 1-17. DOI: https://doi.org/10.1007/s40899-021-00537-5
Falowo, O. O., Akindureni, Y., & Ojo, O. (2017). Irrigation and drinking water quality index determination for groundwater quality evaluation in Akoko Northwest and Northeast Areas of Ondo State, Southwestern Nigeria. American Journal of Water Science and Engineering, 3(5), 50-60. DOI: https://doi.org/10.11648/j.ajwse.20170305.11
Falowo, O. O., Amodu, M. B., Oluwasegunfunmi, V., Aliu, A., & Otuaga, M. P. (2019b). Groundwater evolution, hydrochemical facies and quality evaluation for irrigation use in Akure, Ondo State, Nigeria. Journal of Geoscience and Environment Protection, 7(08), 118. DOI: https://doi.org/10.4236/gep.2019.78009
Falowo, O., Oluwasegunfunmi, V., Akindureni, Y., Olabisi, W., & Aliu, A. (2019a). Groundwater physicochemical characteristics and water quality index determination from selected water wells in Akure, Ondo State, Nigeria. American Journal of Water Resources, 7(2), 76-88.
Gbadebo, A. M., Dimowo, B. O., Taiwo, A. M., Sojinu, O. S. & Olajide, E. S. (2026a). Hydrogeochemical Assessment of Water from Selected Communities in the Niger Delta Region. Discover Water, 6 (20). https://doi.org/10.1007/s43832-025-00335-6 DOI: https://doi.org/10.1007/s43832-025-00335-6
Gbadebo, A. M., Adesanya, A. D., Gbadebo, O. O. & Dimowo, B. O. (2026b). Hydrogeochemical Evaluation of Groundwater Quality in Nigeria’s Federal Capital Territory: Suitability for Drinking and Irrigation Purposes. Physics and Chemistry of the Earth, 144 (104558): 1-16. https://doi.org/10.1016/j.pce.2026.104558 DOI: https://doi.org/10.1016/j.pce.2026.104558
Gbadebo, A. M., Egbedara, T. A., Gbadebo, O. O. & Dimowo, B. O. (2026c). Geochemical Evaluation of Groundwater Quality in Yewa for Drinking and Irrigation Purposes. Water Science, 40 (54): 1 - 19. https://doi.org/10.1007/s44533-026-00055-3 DOI: https://doi.org/10.1007/s44533-026-00055-3
Gbadebo, A. M., Ofili, E. Duru, C. M., Makanjuola, O. O., Gbadebo, O. O., Igwe, D. O., Osianor, E. O., Otubu, K. K., Adegbanke, G. T., Owoola, I. M., Bello, A. A., Egbedara, T. A., Ola-Iya, I. E., Adesanya, A. D., Omolafe, O. F., Samuel, C. E., Francis, V. J., Michael, T. K. & Dimowo, B. O. (2026d). Health Risk Assessment of Nitrate and Fluoride in Groundwater Across 10 Nigerian States. Environmental Geochemistry and Health, 48 (221): 1-36. https://doi.org/10.1007/s10653-026-03064-4 DOI: https://doi.org/10.1007/s10653-026-03064-4
Gbadebo, A. M., Momoh, A. O., Omolafe, O. F., Adesanya, A. D., Gbadebo, O. O., Ola-Iya, I. E., Egbedara, T. A., Bello, A. A., Owoola, I. M., Adegbanke, G. T., Otubu, K. A., Osianor, E. O., Igwe, D. O., & Dimowo, B. O. (2026e). Evaluating Microbial and Physicochemical Contamination of Groundwater in Southwestern Nigeria and the Federal Capital Territory: A Regulatory Compliance Assessment. International Journal of Environmental Research and Earth Science, 12 (4): 64-89. https://doi.org/10.70382/caijeres.v12i4.074 DOI: https://doi.org/10.70382/caijeres.v12i4.074
Hammer, Ø., Harper, D. A. T., & Ryan, P. D. (2001). PAST: Paleontological Statistics Software Package for Education and Data Analysis. Palaeontologia Electronica, 4(1), 1–9. https://palaeo-electronica.org/2001_1/past/issue1_01.htm (Software version 4.03).
IBM Corporation (2021). IBM SPSS Statistics for Windows, Version 28.0. Armonk, NY: IBM Corp.
Ige, O. O., Owolabi, A. T., Olabode, O. F., & Obasaju, D. O. (2022). Groundwater quality evaluation: a case study of Igando waste dumpsite, southwestern Nigeria. Applied water science, 12(4), 79. DOI: https://doi.org/10.1007/s13201-022-01601-x
Igwe, O., & Omeka, M. E. (2022). Hydrogeochemical and pollution assessment of water resources within a mining area, SE Nigeria, using an integrated approach. International Journal of Energy and Water Resources, 6(2), 161-182. DOI: https://doi.org/10.1007/s42108-021-00128-2
Institute of Medicine (IOM) (2011) Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Total Water and Macronutrients. In A. C. Ross, C. L. Taylor, A. L. Yaktine, & H. B. Del Valle (Eds.), Dietary Reference Intakes for Vitamin D and Calcium. US Committee to Review Dietary Reference Intakes for Vitamin D and Calcium. Washington (DC). National Academies Press. Retrieved 3rd October, 2025 from https://www.ncbi.nlm.nih.gov/books/NBK56068/table/summarytables.t4/
Institute of Medicine (IOM) (2005) Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: National Academies Press. 618pp. Available at https://nap.nationalacademies.org/cart/download.cgi?record_id=10925
Iwugo, K. O., D’Arcy, B., & Andoh, R. (2003). Aspects of land-based pollution of an African coastal megacity of Lagos. Proceedings of the International Specialized IWA Conference, Dublin, Ireland.
Jibrin, N. A., Mairami, F. M., & Husseini, H. U. (2015). Assessment of groundwater quality in some rural areas of the federal capital territory, Abuja, Nigeria. International Journal of Scientific Research and Education, 3, 3363-3376.
Jones, H. A., & Hockey, R. D. (1964). The geology of part of south-western Nigeria. Geological Survey of Nigeria Bulletin, 31.
Kacmaz, H., and Nakoman, M. E. (2010). Evaluation of shallow ground-water 557 quality for irrigation purposes in the Koprubasi Ura-nium Area (Manisa, Turkey). Balkan Water Observation and Information System (BALWOIS), 25: 1–9.
Kayode, M. O., Tomori, W. B., Okoronkwo, E. A., & Adiat, K. A. N. (2024). Seasonal variation of groundwater quality in a basement complex geology of Ado Ekiti Nigeria using water quality index model. Journal of Umm Al-Qura University for Applied Sciences, 1-26. DOI: https://doi.org/10.1007/s43994-024-00195-1
Kelly, W.P. (1940). Permissible Composition and Concentration of Irrigated Waters. Proceedings of the American Society of Civil Engineers, 66: 607-613pp
Kumar, S. K., Babu, S. H., Rao, P. E., Selvakumar, S., Thivya, C., Muralidharan, S. and Jeyabal, G. (2017). Evaluation of water quality and hydrogeochemistry of surface and groundwater, Tiruvallur District, Tamil Nadu, India. Applied Water Science, 7(5). 2533-2544. DOI: https://doi.org/10.1007/s13201-016-0447-7
Lehmann, N., Lantuit, H., Böttcher, M. E., Hartmann, J., Eulenburg, A., & Thomas, H. (2023). Alkalinity generation from carbonate weathering in a silicate-dominated headwater catchment at Iskorasfjellet, northern Norway. Biogeosciences, 20(16), 3459-3479. DOI: https://doi.org/10.5194/bg-20-3459-2023
Li, P., Wu, J., Qian, H., Zhang, Y., Yang, N., Jing, L. and Yu, P. (2016). Hydrogeochemical characterization of groundwater in and around a wastewater irrigated forest in the southeastern edge of the Tengger Desert, Northwest China. Exposure and Health. 8(3):331-348. DOI: 10.1007/s12403-016-0193-y DOI: https://doi.org/10.1007/s12403-016-0193-y
Longe, E. O. (2011). Groundwater resources potential in the coastal plain sands aquifers, Lagos, Nigeria. Research Journal of Environmental and Earth Sciences, 3(1), 1–7.
Longe, E. O., Malomo, S., & Olorunniwo, M. A. (1987). Hydrogeology of Lagos metropolis. Journal of African Earth Sciences, 6(2), 163–174. DOI: https://doi.org/10.1016/0899-5362(87)90058-3
Mafimisebi, P. (2024). Assessment of Groundwater Suitability for Irrigation Purposes: A Case Study in Malajoye, Epe Area, Lagos, Nigeria. International Journal of Trendy Research in Engineering and Technology, 8 (3): 47 - 55. DOI: https://doi.org/10.54473/IJTRET.2024.8308
Martins, G. and Mafimisebi, P. (2024a). Assessment of Groundwater Quality and Saltwater Intrusions in Coastal Aquifers in Ayetoro Community, Ondo State Nigeria. International Journal of Trendy Research in Engineering and Technology, 8 (5): 11 - 17. DOI: https://doi.org/10.54473/IJTRET.2024.8503
Microsoft Corporation. (2021) Microsoft Excel, Version 2021. Redmond, WA: Microsoft Corporation.
Martins, G., & Mafimisebi, P. (2024b). Impacts of Sewage Wastewater on Groundwater Quality and Health Risk in Makoko, Lagos, Nigeria. Asian Journal of Basic Science & Research, 6(3), 100-110. DOI: https://doi.org/10.38177/AJBSR.2024.6312
Mussa, K. R., & Mjemah, I. C. (2023). Using hydrogeochemical facies and signatures for groundwater characterization and evolution assessment in aquifers with contrasting climate and geology in Tanzania. Applied Water Science, 13(10), 201. DOI: https://doi.org/10.1007/s13201-023-01977-4
Nagarju, A., Suresh, S., Killaham, K. and Hudson-Edwards, K. A. (2006). Hydrogeochemistry of waters of manampeta barite mining area Cuddapah Basin, Andhra Pradesh India. Turkish Journal Engineering Environmental Science, 30: 203–219.
National Academies of Sciences, Engineering, and Medicine (NASEM) (2019a) Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes. In Oria M, Harrison M, Stallings VA, editors. Dietary Reference Intakes for Sodium and Potassium. Health and Medicine Division; Food and Nutrition Board; US Committee to Review the Dietary Reference Intakes for Sodium and Potassium, Washington (DC): National Academies Press. Retrieved 3rd October 2025 from: https://www.ncbi.nlm.nih.gov/books/NBK545442/table/appJ_tab3/
National Academies of Sciences, Engineering, and Medicine (NASEM) (2019b) Dietary Reference Intakes (DRIs): Tolerable Upper Intake Levels, Elements. In Oria M, Harrison M, Stallings VA, editors. Dietary Reference Intakes for Sodium and Potassium. Health and Medicine Division; Food and Nutrition Board; US Committee to Review the Dietary Reference Intakes for Sodium and Potassium, Washington (DC): National Academies Press. Retrieved 3rd October 2025 from: https://www.ncbi.nlm.nih.gov/books/NBK545442/table/appJ_tab9/
National Environmental Standards and Regulations Enforcement Agency (NESREA), (2011). National Environmental (Surface and Groundwater Quality Control) Regulations. The Federal Republic of Nigeria Official Gazette, 98 (49): B 693-727. Retrieved 13th May 2025 from https://faolex.fao.org/docs/pdf/nig145947.pdf
Nkpoidet, M. M., Udosen, N. I., & Thomas, J. E. (2025). Hydrochemical assessment of groundwater quality using water quality index, irrigation indices, and corrosivity models in a hydrocarbon-impacted coastal aquifer. Discover Geoscience, 3(1), 111. DOI: https://doi.org/10.1007/s44288-025-00220-8
Ojeh, V., Balogun, A., & Okhimamhe, A. (2016). Urban-rural temperature differences in Lagos. Climate, 4(29), 1–18. DOI: https://doi.org/10.3390/cli4020029
Okafor, V.N., Omokpariola, D.O., Obumselu, O.F. and Eze, C.G. (2023). Exposure risk to heavy metals through surface and groundwater used for drinking and household activities in Ifite Ogwari, Southeastern Nigeria. Applied Water Science, 13 (105): 1-20. DOI: https://doi.org/10.1007/s13201-023-01908-3
Okoroh, D. O. and Ibuot, J. C. (2022). Hydrogeochemical assessment of groundwater quality: a case study of Federal College of Education (Technical), Omoku, Rivers State. Water Practice & Technology, 17 (7): 1458 - 1469. DOI: https://doi.org/10.2166/wpt.2022.077
Olatunji, J. A., Odediran, O. A., Obaro, R. I., & Olasehinde, P. I. (2015). Assessment of groundwater quality of Ilorin metropolis using water quality index approach. Nigerian journal of technological development, 12(1), 18-21. DOI: https://doi.org/10.4314/njtd.v12i1.4
Omali, A. (2024). Evaluation of Hydrochemical Facies of Groundwater in Ajaokuta, North-Central, Nigeria. In: Ksibi, M., et al. Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions (4th Edition). EMCEI 2022. Advances in Science, Technology & Innovation. Springer, Cham. https://doi.org/10.1007/978-3-031-51904-8_96 DOI: https://doi.org/10.1007/978-3-031-51904-8_96
Omatsola, M. E., & Adegoke, O. S. (1981). Tectonic evolution and Cretaceous stratigraphy of the Dahomey Basin. Nigeria Journal of Mining and Geology, 18(1), 130–137.
Omeru, T., Olabaniyi, S. B., Adegie, A. T., Avwenagha, E. O. and Ajao, O. A. (2018). Assessment of Physicochemical Properties of Epe Lagoon Water, Southwest Nigeria. Nigeria Journal of Science and Environment, 16 (1): 133 - 148.
Oyedele, K. F., & Oladele, S. (2011). Geoelectrical assessment of groundwater potential in the coastal aquifer of Lagos, Nigeria. Advanced Research in Aquatic Environment, 2, 29–36. https://doi.org/10.1007/978-3-642-24076-8_4 DOI: https://doi.org/10.1007/978-3-642-24076-8_4
Panjaitan, D., Tarigan, J., Rauf, A. and Nababan, E. S. M. (2018). Determining sea water intrusion in shallow aquifer using Chloride Bicarbonate Ratio Method. IOP Conference Series: Earth and Environmental Science, 205: 012029 DOI: https://doi.org/10.1088/1755-1315/205/1/012029
Ragunath, H. M. (1987). Groundwater. Wiley Eastern Ltd, New Delhi. 563p
Raheja, H., Goel, A., & Pal, M. (2024). Assessment of groundwater quality and its vulnerability for safe drinking purpose. Journal of Hydroinformatics, 26(9), 2302-2324. DOI: https://doi.org/10.2166/hydro.2024.122
Raju, N. J., Shukla, U. K., & Prahlad Ram, P. R. (2011). Hydrogeochemistry for the assessment of groundwater quality in Varanasi: a fast-urbanizing center in Uttar Pradesh, India. Environmental monitoring and assessment, 173: 279-300. DOI: https://doi.org/10.1007/s10661-010-1387-6
Ratri, D., Putra, D. P. E. and Wilopo, W. (2021). Groundwater geochemistry and hydrogeochemical processes assessment in Bantul, Yogyakarta, Indonesia. In IOP Conference Series: Earth and Environmental Science (Vol. 958, No. 1, p. 012013). IOP Publishing DOI: https://doi.org/10.1088/1755-1315/958/1/012013
Rawat, K. S., Singh, S. K. and Gautam, S.K. (2018). Assessment of groundwater quality for irrigation use: a peninsular case study. Applied Water Science, 8: 233. DOI: https://doi.org/10.1007/s13201-018-0866-8
Revelle, R. (1941). Criteria for Recognition of Sea Water in Groundwater. Eos, Transactions American Geophysical Union, 22: 595-659 DOI: https://doi.org/10.1029/TR022i003p00593
Richard, L. A. (1954). Diagnosis and improvement of saline alkali soils. US Department of Agriculture, Hand book no. 60, p 160 DOI: https://doi.org/10.1097/00010694-195408000-00012
Rutharvel, M. K., Kumaraswamy, K., Dhanakumar, S., Balachandar, D. and Periyasamy, M. (2010). Assessment of Groundwater Quality for Irrigation Purpose in Vellore District, Tamil Nadu, India: A Spatial Approach Using GIS. The Indian Geographical Journal, 85 (1): 1-28.
Salami, L. and Ayinde, B. A. (2025). A comprehensive investigation of groundwater quality in Lagos State University, Epe, Lagos State, Nigeria. Global Journal of Engineering and Technology Advances, 22(03): 123-130. DOI: https://doi.org/10.30574/gjeta.2025.22.3.0051
Samal, P., Mohanty, A. K., Khaoash, S., & Mishra, P. (2022). Hydrogeochemical evaluation, groundwater quality appraisal, and potential health risk assessment in a coal mining region of Eastern India. Water, Air, & Soil Pollution, 233(8), 324. DOI: https://doi.org/10.1007/s11270-022-05811-6
Samanta, P., Mukherjee, A. K., Pal, S., Senapati, T., Mondal, S. and Ghosh, A. R. (2013). Major ion chemistry and water quality assessment of waterbodies at Golapbag area under Barddhaman Municipality of Burdwan District, West Bengal, India. International Journal of Environmental Sciences, 3(6), 1938-1956.
Sanad, H., Mouhir, L., Zouahri, A., Moussadek, R., El Azhari, H., Yachou, H., Ghanimi, A., Oueld Lhaj, M. & Dakak, H. (2024). Assessment of groundwater quality using the pollution index of groundwater (PIG), nitrate pollution index (NPI), water quality index (WQI), multivariate statistical analysis (MSA), and GIS approaches: A case study of the Mnasra Region, Gharb Plain, Morocco. Water, 16(9): 1263.. https://doi.org/10.3390/w16091263 DOI: https://doi.org/10.3390/w16091263
Schoeller, H. (1965). Qualitative Evaluation of Ground Water Resources. In Methods and Techniques of Groundwater Investigation and Development; Schoeller, H., Ed.; The United Nations Educational, Scientific and Cultural Organization: Paris, France, pp. 44–52.
Sehlaoui, H., Hassikou, R., Moussadek, R., Zouahri, A., Douaik, A., Iiach, H., Ghanimi, A. & Dakak, H. (2020). Evaluation of water quality for agricultural suitability in the Benslimane region, Morocco. Environmental Monitoring and Assessment, 192(9), 587. DOI: https://doi.org/10.1007/s10661-020-08530-9
Serge Gaëtan, S. É., Marie Michelle, C. H., Ouindinboudé Jacques, K., Poulouma Louis, Y., & Idriss, S. (2022). Hydrogeochemistry of shallow groundwater and suitability to irrigation: the case of the Karfiguéla paddy field in Burkina Faso. Water, 14(16), 2574. DOI: https://doi.org/10.3390/w14162574
Shuaibu, A., Kalin, R. M., Phoenix, V., Banda, L. C., & Lawal, I. M. (2024). Hydrogeochemistry and water quality index for groundwater sustainability in the Komadugu-Yobe Basin, Sahel Region. Water, 16(4), 601. DOI: https://doi.org/10.3390/w16040601
Singh, K. K., Tewari, G. and Kumar, S. (2020). Evaluation of groundwater quality for suitability of irrigation purposes: a case study in the Udham Singh Nagar, Uttarakhand. Hindawi Journal of Chemistry, 2020 (1), 6924026. DOI: https://doi.org/10.1155/2020/6924026
Soltani-Gerdefaramarzi, S., & Rahmani-Samani, Z. (2025). Investigating temporal and spatial changes in groundwater pollution in the Yazd-Ardakan plain using the Pollution Index of Groundwater (PIG). Journal of Geography and Environmental Hazards.
Standard Organization of Nigeria (SON), (2015). Nigerian Standard for Drinking Water Quality. Nigerian Industrial Standard - NIS-554-2015. Retrieved 13th May 2025 from https://africacheck.org/sites/default/files/Nigerian-Standard-for-Drinking-Water-Quality-NIS-554-2015.pdf
Subba-Rao, N. (2012). PIG: A numerical index for dissemination of groundwater contamination zones. Hydrological Processes, 26: 3344–3350. DOI: https://doi.org/10.1002/hyp.8456
Sulaiman, M. B., Umar, A. M., Yusuf, A., Adamu, I. M., Rafi, A. B., Akinlotan, O. O., & Bello, A. M. (2025). Hydrogeochemical characteristics and groundwater quality assessment for drinking and irrigation purposes in the rural areas of Gombe, Nigeria. Discover Water, 5(1), 81. DOI: https://doi.org/10.1007/s43832-025-00289-9
Szobolces, I. and Darab, K. (1968). In Irrigation, Drainage and Salinity, Int. Source Book, Hutchinson & Co., London, 510p.
The Editors of Encyclopaedia Britannica (2024, January 5). Epe. Encyclopedia Britannica. https://www.britannica.com/place/Epe
Todd, D. K. (1980). Groundwater Hydrology, 2nd edn. Wiley, New York, 535pp
Ugbor, C. C., Nwali, O. I., & Ugwuoke, C. I. (2022). Physicochemical evaluation and irrigation quality assessments of water resources: a case study of Okigwe and its environs Southeastern Nigeria. International Journal of Energy and Water Resources, 8(2), 255-268. DOI: https://doi.org/10.1007/s42108-022-00200-5
Whiteman, A. (1982). Nigeria: Its petroleum geology, resources and potential. Graham Trotman. DOI: https://doi.org/10.1007/978-94-009-7361-9
Wilson, R. C. C., & Willians, C. A. (1979). Oceanic transform structures and the development of Atlantic continental margin sedimentary basin: A review. Journal of the Geological Society of London, 136, 311–320. DOI: https://doi.org/10.1144/gsjgs.136.3.0311
World Health Organization (WHO), (2022). Guidelines for drinking-water quality: fourth edition incorporating the first and second addenda. Geneva. Licence: CC BY-NC-SA 3.0 IGO. 583pp. Retrieved 6th March, 2024 from https://iris.who.int/bitstream/handle/10665/352532/97892400 45064-eng.pdf
Yahaya, T., Oladele, E., Salisu, T. F., Izuafa, A., Afolayan, F., Abdulgafar, I. B., & Omotayo, B. A. (2022). Quality Assessment of Groundwater in Mowe, Ogun State, Nigeria. Tropical Journal of Natural Product Research, 6(5). DOI: https://doi.org/10.26538/tjnpr/v6i5.25
Yang, J., Liu, H., Tang, Z., Peeters, L. and Ye, M. (2022). Visualization of aqueous geochemical data using Python and WQChartPy. Groundwater, 60(4): 555-564. DOI: https://doi.org/10.1111/gwat.13185
Yusuf, M. A., & Abiye, T. A. (2019). Risks of groundwater pollution in the coastal areas of Lagos, southwestern Nigeria. Groundwater for Sustainable Development, 9, 100222. DOI: https://doi.org/10.1016/j.gsd.2019.100222
Article Sidebar
