Appraisal of groundwater quality and hydrochemistry in three regions of Ghana: Implications for drinking purposes

Abstract

Groundwater is the most relied upon source of water for rural areas and small communities with no access to national water systems. The Community Water and Sanitation Agency (CWSA) in Ghana is an institution that facilitates the provision of water and sanitation services to small towns and communities, hence it has engineered several boreholes all over the country. However, some of these boreholes have quality challenges. Hence this study was carried out to assess the quality and hydrochemical controls of such boreholes in the Ashanti, Upper East and Central Regions of Ghana. A total of 45 boreholes were sampled across these areas and subjected to physicochemical, microbial, and heavy metal analysis. Analysis of the groundwater in the Ashanti Region indicates that its quality is negatively impacted by its iron, manganese, and arsenic content. Same was observed for the Central Region. While in the Upper East Region, total hardness, fluoride, nitrate, and arsenic are the parameters that impact the groundwater quality greatly. Water quality index was used to assess the suitability of the groundwater for domestic purposes and based on this index, 80 % of the water samples were classified as either having an excellent or good quality, while about 7 % were classified as unsuitable for domestic purposes, across all regions. The suitability of the groundwater for irrigational purposes was assessed using sodium adsorption ratio (SAR), percentage sodium (% Na), and Kelly's index (KI). Based on SAR and % Na, all the water samples were suitable for irrigation, while 9 % were unsuitable based on KI. This study provides a comprehensive information on some of the CWSA boreholes with quality challenges. This kind of information is critical and useful when considering what options and treatment technologies would be suitable to address the challenges that these boreholes have.