Hydrochemical characterization of groundwater in the Accra plains of Ghana
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Abstract
Chemical and isotopic analyses are used to characterize and identify the relevant water-rock interactions, which are responsible for the poor groundwater quality in the Accra Plains. Four main water types are identified. Processes that singly or in combination influence the chemical composition of each water type include halite dissolution carbonate dissolution and precipitation, seawater intrusion, cation exchange, evaporative concentration of solutes and aluminosilicates dissolution. These processes contribute considerably to the concentration of major ions in the groundwater. Stable isotope contents of the groundwater suggest mainly direct integrative recharge. A few samples plot along the meteoric-seawater mix line which is coincidentally the evaporative line. The Cl−/Br− ratios of some of these are close to 300 confirming marine origin, others probably concentrated by evaporation have their Cl−/Br− ratios significantly lower than 300. Groundwater is qualitatively good for drinking purposes only along the foothills of the Akwapim Togoland ranges.
Keywords
Accra Plains Dissolution Ghana Groundwater quality PrecipitationNotes
Acknowledgements
I wish to thank Professor Niels O. Jorgensen for arranging for the isotope analysis at the Geological institute at the University of Copenhagen Denmark. This project was partly supported by the Water Research Institute (CSIR, Ghana).
References
- Akiti TT (1980) Etude geochimique et isotopique de quelques aquifere du Ghana. Ph.D. thesis, Universite’ de Paris-SudGoogle Scholar
- Akiti TT (1986) Environmental isotope study of groundwater in crystalline rocks of the Accra Plains. 4th Working Meeting Isotopes in Nature. Proceedings of an advisory group meeting. IAEA, Vienna, September 1986Google Scholar
- Amuzu AT (1978) The quality of groundwater in the Accra Plains of Ghana. Unpublished Technical Report, Water Resources Research Institute (CSIR), AccraGoogle Scholar
- Appelo CAJ, Postma D (1999) Chemical analysis of groundwater. geochemistry, groundwater and pollution. Balkema, RotterdamGoogle Scholar
- Barcelona M, Gibb JP, Helfrich JA, Garske EE (1985) Practical guide for groundwater sampling. Illinois State Water Survey ISWS Contract Report 374Google Scholar
- Brady NC (1974) Th nature and properties of soils, 8th edn. Macmillan, New YorkGoogle Scholar
- Brady PV, Walther JV (1989) Control of silica dissolution rates in neutral and basic solutions at 250C. Geochim Cosmochim Acta 53:2823–30CrossRefGoogle Scholar
- Brammer H (1967) Soils of the accra plains, Soil Research Institute. CSIR Memoir No. 3. GhanaGoogle Scholar
- Claasen HC (1982) Guidelines and techniques for obtaining water samples that accurately represent the water quality for an aquifer. US geological survey open file report 82–1024 pp 49Google Scholar
- Craig H (1961) Isotopic variations in meteoric water. Science 133:1702–1703CrossRefGoogle Scholar
- Davis SN, DeWiest RJM (1966) Hydrogeology. Wiley, New York, 463 ppGoogle Scholar
- Dickson KB, Benneh G (1980) A new geography of Ghana. Longman, LondonGoogle Scholar
- Durov SA (1948) Natural waters and graphic representation of their compositions. Dokl Akad Nauk SSSR 59:87–90Google Scholar
- Freeze AR, Cherry JAQ (1979) Groundwater. Prentice-Hall, Englewood Ciffs, New Jersey 07632Google Scholar
- Hounslow AW (1995) Water Quality Data Analysis and interpretation, Lewis, Boca RatonGoogle Scholar
- Jankowski J, Acworth RI, Shekarforoush S (1998) Reverse ion exchange in a deeply weathered porphyritic dacite fractured aquifer system, Yass, New South Wales, Australia. In: Arehart GB, Hulston JR (eds) Proceedings of the 9th International Symposium. Water-rock interaction, Taupo, New Zealand, 30 March-3, Balkema, Rotterdam, April 1998:243–246Google Scholar
- Junner NR, Bates DA (1945) Reports on the geology and hydrology of the coastal areas east of the Akwapim ranges. Ghana Geological Survey Memoir No. 7Google Scholar
- Kess GO (1985) The mineral and rock resources of Ghana. Balkema, RottendamGoogle Scholar
- Kortatsi BK, Jørgensen NO (2001) The origin of high salinity waters in the Accra plains groundwater. In: First international conference on saltwater intrusion and coastal aquifers. Monitoring, modeling, and management. Essaouira, Morocco, April 23–25Google Scholar
- Langmuir D (1971c) The geochemistry of some carbonate groundwaters in central Pennsylvania. Geochim Cosmochim Acta 35:1023–45CrossRefGoogle Scholar
- Langmuir D (1997) Aqueous Environmental Geochemistry. Prentice-Hall, New JerseyGoogle Scholar
- Lloyd JW (1965) The hydrochemistry of the aquifers of north-eastern Jordan. J Hydrol 3:319–330CrossRefGoogle Scholar
- Lloyd JW, Heathcote JA (1985) Natural inorganic hydrochemistry in relation to groundwater. An introduction. Clarendon, OxfordGoogle Scholar
- Mazor E (1976) Interpretation of environmental isotope and hydrochemical data in groundwater hydrology. Proceedings of an advisory group meeting, Vienna 27–31 January 1975. International Atomic Energy Agency, Vienna, 1976Google Scholar
- Nii Consult (1998) Information building block. Ghana water management study. Unpublished Consultancy Report for the Ministry of Works and Housing, Ghana, DANIDA, World BankGoogle Scholar
- Nilsen R, Grammeltvedt G (1993) Chemical weathering of ore and host rock in six Norwegian sulphide mines. Norges geologiske undersokelse report 93.037, Ngu, Trondheim, NorwayGoogle Scholar
- Parkhurst DL, Appelo CAJ (1999) Phreeqc for windows version 1.4.07. A hydrogeochemical transport model. US Geological Survey SoftwareGoogle Scholar
- Quist L G (1976) A preliminary report on the groundwater assessment of the Accra Plains. Unpublished Technical Report, Water Resources Research Institute. CSIR, AccraGoogle Scholar
- Sen Z, Al-Dakheel A (1986) Hydrochemical facies evaluation in Umm Er Radhuma limestone, Eastern Saudi Arabia. Groundwater 21:626–636Google Scholar
- Tardy Y (1971) Characterization of the principal weathering types by the geochemistry of waters from European and African crystalline massifs. Chem Geol 7:253–271CrossRefGoogle Scholar
- World Health Organisation (WHO) (1993) Guidelines for drinking water quality. Revision of the 1984 guidelines. Final task group meeting. Geneva 21–25 September 1992Google Scholar
- WRRI (1996) Groundwater assessment report on the Accra Plains. Unpublished Technical Report, Water Resources Research Institute (CSIR) AccraGoogle Scholar