Hydrochemical framework of groundwater in the Ankobra Basin, Ghana

Author: Kortatsi, Benony

Source: Aquatic Geochemistry, Volume 13, Number 1, March 2007 , pp. 41-74(34)

Publisher: Springer

Buy & download fulltext article:

Price: $47.00 plus tax (Refund Policy)

Abstract:

Hydrochemical and stable isotope (¹⁸O and ²H) analyses of groundwater samples were used to establish the hydrochemistry of groundwater in the Ankobra Basin. The groundwater was generally mildly acidic, low in conductivity and undersaturated with respect to carbonate phases. Major ions except bicarbonate were low and dissolved silica was moderately high. Silicate minerals weathering is probably the main process through which major ions enter the groundwater. Groundwater samples clustered tightly along the Global Meteoric Water Line suggesting integrative, smooth and rapid recharge from meteoric origin. The majority of the boreholes and a few hand dug wells cluster towards the Ca-Mg-HCO₃ dominant section of the phase diagram, in conformity with the active recharge and short residence time shown by the isotope data. Aluminium, arsenic, manganese, iron and mercury were the only trace metals analysed with concentrations significantly above their respective detection limits. Approximately 20%, 5%, 40% and 25% respectively of boreholes had aluminium, arsenic, iron and manganese concentrations exceeding the respective WHO maximum acceptable limits for drinking water. The relatively large percentage of boreholes with high concentration of aluminium reflects the acidic nature of the groundwater.

Keywords: Ghana; Groundwater quality; Hydrochemistry; Maximum acceptable limit; Silicate weathering

Document Type: Research article

DOI: http://dx.doi.org/10.1007/s10498-006-9006-4

Affiliations: 1: Email: kortatsi@hotmail.com

Publication date: 2007-03-01