Presence of arsenic, iron and manganese in groundwater within the gold-belt zone of Ghana

About 45% of the total drinking water in Ghana is produced from groundwater. The presence of arsenic and manganese in groundwater above the recommended WHO drinking- water guidelines pose a threat to consumers' health. To provide additional information on groundwater quality in the gold-belt zone of Ghana, nearly 290 well water samples from three regions namely Ashanti, Western and Brong-Ahafo, were analyzed for the presence of arsenic, iron and manganese. It was found that 5–12% of sampled wells had arsenic levels exceeding the 10 μg l −1 —WHO provisional guideline value. Communities within the studied area with high arsenic presence in their groundwater are located within the Birimian and Tarkwaian geological formations. Most of these arsenic contaminated wells (70%) have been in use for more than 15 years. Brong-Ahafo, Ashanti and Western regions had 5%, 25% and 50% of wells, respectively with iron levels above 0.3 mg l −1 , the drinking-water guideline value commonly accepted for iron. Thirteen percent of wells in Ashanti and 29% in the Western region exceeded 0.4 mg l −1 —the WHO health-based guideline value for manganese.