Assessment of Groundwater Quality and Governance in Four Coastal Communities of Ghana

Abstract

This study presents the findings of the assessment of groundwater quality, associated health risks, and groundwater governance in four coastal communities (Essiama, Winneba, Accra, and Keta) in Ghana. Membrane filtration method, Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI), and Nemerow’s Pollution Index (NPI) were used to assess groundwater quality while Quantitative Microbial Risk Assessment (QMRA), incremental life cancer risk, and hazard quotient were employed to assess the health risks associated with groundwater use. In addition, policy document review, focused group discussions, and expert-based assessment were employed to assess groundwater governance status. The results showed that mean total coliforms and Escherichia coli ranged respectively from 123.40 to 501.30 and 30.98 to 141.90 CFU/100 ml, respectively, in the selected communities. Mean NO3 concentrations exceeded the World Health Organization’s standards in Winneba and Accra for both the rainy and the dry seasons. Arsenic was higher than the acceptable level in Accra and Keta during the dry season, while Fe was higher than the acceptable levels in Accra in both seasons. CCME-WQI indicated that groundwater quality ranged from poor to marginal and NPI revealed that NO3, As, and Fe contributed to the deterioration of the groundwater sources. QMRA showed that exposure to E. coli O157:H7 through drinking groundwater ranged from 5 to 23 cells per day and the annual risk of infection and illness from E. coli O157:H7 for all communities was 1 for drinking. Arsenic showed non-cancer risks in Accra and Keta. Assessment of groundwater governance capacity showed that overall groundwater governance capacity in Ghana was incipient. To protect groundwater resources in Ghana, there is a need to regulate activities that degrade groundwater sources, and also build groundwater governance capacity, and promote public participation in the process.