Assessment of groundwater quality using the National Sanitation Foundation Water Quality Index within Benin City, Nigeria

Abstract

This study assessed groundwater quality by utilising the National Sanitation Foundation Water Quality Index (NSFWQI) protocol to ascertain the suitability of the water for drinking. Ten (10) groundwater samples were collected within the Benin municipality area located in the South-South region of Nigeria. The analysed physicochemical and biological parameters were pH, temperature, total dissolved solids (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD), phosphates, nitrates, turbidity, and total coliforms. All parameters were analysed using standard methods. The overall WQI values obtained for the samples were in the range of 55.3 – 68.44, indicating that all of the samples had a moderate or medium water quality and could be suitable for drinking only after proper treatment. The non-conforming physicochemical parameters as compared to the World Health Organisation (WHO) and Standard Organisation of Nigeria (SON) set guidelines were pH (4.51 - 6.65), PO43- (0.29 - 0.82 mg/L), BOD (1.52 - 7.2 mg/L) coupled with the presence of total coliform (20 -160 MPN/100 mL). Hence, water from these locations requires minimal treatment before consumption and domestic use.