Hydrogeochemical characterization and spatial analysis of groundwater quality in the Bono East Region, Ghana

Reliance on groundwater for municipal, agricultural, and industrial water supplies is steadily growing in the Bono East Region of Ghana. However, much of the region lacks adequate groundwater characterization, which is essential for its sustainable management and equitable distribution. This study was, therefore, undertaken to analyze groundwater quality for drinking and irrigation as well as identify the factors influencing its chemistry in the Bono East Region of Ghana. A total of 26 groundwater samples were collected and analysed using hydrogeochemical, geostatistical, and GIS-based methods. The results indicate that the abundance of major cations and anions in groundwater follows the order: Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ and Cl⁻ > HCO₃⁻ > SO₄²⁻, respectively. Five hydrochemical facies, namely Ca–HCO₃, Na–HCO₃, Ca–Na–HCO₃, Na–Cl, and Ca–Cl were identified in the study area. These facies are influenced by natural processes such as rock weathering, ion exchange, precipitation, and evaporation, along with human activities like fertilizer application and domestic wastewater discharge. In the southern and central parts of the study area, the groundwater is generally soft (total hardness < 75 mg/L), fresh (total dissolved solids < 1000 mg/L), and suitable for drinking (water quality index < 50) and irrigation. However, in the northern part, especially in the Kintampo North Municipality, the levels of EC, TDS, SO₄²⁻, Ca²⁺, TH, Cl⁻, K⁺, and Na⁺ in the groundwater are high, making it unsuitable for drinking and irrigation. Measures to safeguard public health and sustain agricultural productivity in these areas are proposed.