Hydrochemical peculiarities and groundwater quality assessment of the Birimian and Tarkwaian aquifer systems in Bosome Freho District and Bekwai Municipality of the Ashanti Region, Ghana

Abstract

The Birimian and Tarkwaian aquifer systems are the main sources of water supply for the Bosome Freho District and Bekwai Municipality inhabitants in the Ashanti region of Ghana. A hydrogeochemical assessment was carried out to ascertain the natural baseline chemistry of the groundwaters and the factors influencing groundwater chemistry in these two areas. A multivariate statistical tool consisting of principal component analysis (PCA) and hierarchical cluster analysis (HCA) together with hydrochemical graphical plots was applied on 64 groundwater samples. The Q–mode HCA results were used to explain the changes in groundwater chemistry along the flow paths where three spatial groundwater zones and water types were delineated. The first type consists of Ca–Mg–HCO3 freshwater (recharge zone), which transitions into Ca–Na–HCO3 or Na–Ca–HCO3 mixed waters (intermediate zone) and finally evolves to the third type of Na–Ca–Mg–HCO3–Cl water (discharge zone). The study also reveals that the natural process influencing water chemistry is groundwater–rock interaction from carbonate and silicate weathering/dissolution, aided by carbonic acid from precipitation and releases concentration of Na+, Ca2+, Mg2+, and HCO3− into the groundwaters significantly. The chloro-alkaline indices also reveal cation exchange as the principal natural factor that controls groundwater chemistry in the area. Inverse geochemical modelling shows the dissolution of primary minerals such as dolomite, plagioclase, halite, gypsum, and precipitation of calcite and chlorite along the groundwater flow path. Anthropogenic activities have little influence on groundwater chemistry. The quality of groundwater in the Bosome Freho District and Bekwai Municipality is suitable for irrigational use and drinking water consumption. The results obtained so far will contribute to research paucity in the study area and serve as a guide for decision-makers for improved water resources management.

Water–Rock Interactions Driving Groundwater Composition in the Pra Basin (Ghana) Identified by Combinatorial Inverse Geochemical Modelling

“…Although calcite is present in the terrain, based on our petrographic analysis, it rarely occurred in our simulated results, thus suggesting that it is a secondary mineral in the groundwater system. Our results are consistent with previous studies [1,9,11,41,42] and provide a strong conclusion that the weathering of silicate minerals is the primary factor driving groundwater chemistry in the Pra Basin.…”

Hydrochemical Characterization of Surface Water and Groundwater in the Crystalline Basement Aquifer System in the Pra Basin (Ghana)

“…Several researchers have used various conventional approaches to assess the quality of water resources for drinking [22][23][24] and irrigation [21,25] purposes. The Water Quality Index (WQI) has been used extensively in various geological terrains to study surface water and groundwater quality for drinking [26,27]. Others have been employed to study irrigation water quality, including the USSL, %Na and Wilcox diagram [21,25,28].…”

“…Table 2 shows the results of selected correlation coefficients between the hydrochemical parameters in the groundwater and highlights relationships between them. They were tested at a significance level of p < 0.05 with r > 0.7 and r < 0.5 indicating strong and weak correlations [27,45], respectively. In the northern zone groundwater samples, there is a strong positive correlation between pH and HCO − 3 , EC and Ca 2+ , EC and HCO − 3 , Ca 2+ and HCO − 3 and Na + and Cl − .…”

“…Correlation coefficients between the hydrochemical parameters in the groundwater, highlighting the relationships between them. They were tested at a significance level of p < 0.05 with r > 0.7 and r < 0.5 indicating stronger and weaker correlations [27,45], respectively. Only the correlations with r-values > 0.7 are considered significant and presented here.…”

Characterization of groundwater in the 'Tamnean' Plutonic Suite aquifers using hydrogeochemical and multivariate statistical evidence: a study in the Garu-Tempane District, Upper East Region of Ghana

“…In addition, the steady rise in excessive agricultural irrigation practices coupled with the abstraction of groundwater for industrial purposes has exacerbated the negative impacts of groundwater quantity and quality (Ounvichit 2011). While the challenge of ensuring sustainable management of groundwater resources has become a universal goal for most countries, the idiosyncrasies of groundwater use warrant holistic diagnosis and approaches (Okofo et al 2021).…”