Abstract

Groundwater quality of the Obuasi municipality was assessed to understand the contamination processes due to the presence of various contaminant sources and complicated geochemical processes and the suitability of groundwater for irrigation and drinking purpose for a sustainable agriculture and basic human needs. Water samples were collected during the raining season when a rise in water table was expected and during the dry season. They were analyzed for major cations and anions. Parameters like sodium adsorption ratio, % sodium, electrical conductivity, total hardness, total dissolve solutes and stoechiometric relations were calculated on the basis of chemical data. A questionnaire was also used to investigate perception of consumers on taste and odour. Comparison of the concentration of the chemical constituents with World Health Organization (WHO) drinking water standards of 2004 and various classifications show that present status of groundwater in Obuasi is good for drinking and irrigation purposes. Concentrations of major cations and anions in the groundwater systems vary spatially and temporally. Abundance of these anions is in the following order: $Ca^{2+}\>>\>Na^+\>>\>Mg^{2+}\>>\>K^+ = HCO_3^-\>>\>Cl^-\>>\> SO_4^{2-}\>>\>H_2SiO_4\>>\>Br^-\>>\>PO_4^{2-}\>>\>F^-$. In terms of rainy season impact, Obuasi groundwater shows dilution and flushing, however, samples show excessive leaching of different chemical components into the groundwater system leading to the enrichment of different anions and cations and this indicate pollution from extraneous sources. No clear correlation between the quality parameters and perceived quality in terms of satisfactory taste response were obtained at electrical conductivity values lower than the threshold minimum acceptable value.

Keywords:

Drinking and irrigation water quality, Ghana, groundwater, Obuasi,

References

Competing interests

The authors have no competing interests.

Open Access Policy

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Copyright

The authors have no competing interests.