Water Quality Index for Evaluating the Quality Status of Ikpoba River in Benin City, Nigeria

Abstract

The dependence on river water for domestic and drinking purposes is a result of scarcity of potable water. River water is easily polluted through the discharge of effluent and the disposal of solid waste. Evaluation of river water quality status is crucial for public health and environmental sustainability. The study used the National Sanitation Foundation Water Quality Index (NSFWQI) model to assess the quality status of the Ikpoba River in Benin City, Nigeria. Nine physicochemical and microbial parameters were analysed for NSFWQI evaluation following standard procedures. These include dissolved oxygen (DO), biochemical oxygen demand (BOD), total dissolved solids (TDS), phosphate, nitrate, turbidity, temperature, pH, and total coliforms. The NSFWQI values for the samples were within the range of 35.97 to 50.59, which falls within the bad and medium ratings; the mean quality status of the river water is bad. The parameters that did not conform to the limits stipulated by national and international regulatory agencies were majorly BOD, TDS, turbidity, and total coliform. The pollution of the river occurs mainly from anthropogenic activities. The water from the Ikpoba River is unfit for drinking and domestic use; it requires prior treatment before use. Effluents released into the river should be treated to minimum standards set by government regulatory agencies, and disposal of solid wastes and open defecation should be curbed.