Sustainability assessment of groundwater in south-eastern parts of the western region of Ghana for water supply

Abstract

The study assessed the physicochemical and biological properties of selected groundwater sources in the Southeastern part of the Western Region, to assess the impact on water quality and health risk. The Piper Trilinear plot was used to categorize the water samples into water types based on the dominant anion and cation concentrations. Statistical analysis (One way ANOVA and two sample t-test) was used to determine the sources of variation in the data at 95% confidence interval. The Water Quality Index (WQI) and Hazard Quotient (HQ) were used to estimate the water quality and health risk respectively. TDS and turbidity were above the acceptable WHO guidelines in 16.7% of the samples with a mildly acidic pH in 83.3% of the water samples. Also, 91.7% of the water samples were contaminated with total coliform (TC) and 25% with e-coli. Generally, the groundwater samples were dominated by Ca²⁺ and HCO^3- ion water types. The variations between parameters were found not significant for all the parameters (p>0.05). Water samples in the North are of good quality with a mean WQI of 96, but of poor quality in the South with a mean WQI of 144.6. HQ values for all the samples were less than 0.1, suggesting less harmful impacts of the heavy metal concentrations on human health. Overall, the results showed the presence of heavy metals in the groundwater sources sampled, however in quantities with low health risks either through oral or dermal channels. Groundwater within the communities is good for domestic purposes but needs treatment for drinking. To improve upon the study, it is recommended that further studies consider a higher number of samples and include other accessible groundwater stations where possible.