African Journal of Water Conservation and Sustainability

ISSN 2375-0936

African Journal of Water Conservation and Sustainability ISSN 2375-0936 Vol. 14 (5), pp. 001-020, May, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Groundwater Chemistry and Quality Assessment of the Coastal Paleocene Aquifer in Togo 

Gnazou M. D. T.1*, Bawa L. M1, Banton O.2 and Djanéyé-Boundjou G.1

1Laboratoire de Chimie de l’Eau, Faculté Des Sciences, Université de Lomé, B.P 1515, Lomé, Togo.
2Laboratoire d’Hydrogéologie, Université d’Avignon et des Pays du Vaucluse, France.

Accepted 7 January, 2026

This paper presents a hydrogeochemical characterization of the Paleocene aquifer in the coastal basin of Togo. During the dry season (March, 2005), piezometric measurements were made on inventoried water wells. Fifty nine (59) water samples were taken for chemical analysis and the results subjected to statistical study. The quantitative variables considered for this purpose were temperature, pH, electrical conductivity, the major and some minor elements. The results showed that the water samples were weakly mineralized. The electrical conductivity did not exceed 1000 µS/cm, but it increased considerably in the sulphate rich samples. Hydrochemistry was dominated by calcium and bicarbonate except where important values of sulphate (967 mg/L) were obtained. The results of chemical analysis allowed the definition of four different hydrochemical facies. The calcic and magnesian bicarbonated facies was the most important. A sodic and potassic bicarbonated facies identified was mainly due to the residence time of water in the reservoir. Principal component analysis showed one pole of mineralization with strong correlations between sulphate, carbonate, magnesium and calcium.

Key words: Hydrochemistry, aquifer, chemical facies, residence time, Paleocene, Togo.