Assessment of River Water Quality in the Benue River Basin Upstream and Downstream of Makurdi, Benue State

This study assesses the water quality of the Benue River at sampling stations upstream and downstream of Makurdi in Benue State, North Central Nigeria, examining the impact of urban activities including municipal wastewater discharge, market waste disposal, and abattoir runoff on river quality parameters. The Benue River is a critical water resource providing drinking water, irrigation, and fisheries livelihoods to millions of people, yet systematic water quality monitoring along the urban reach of the river is infrequent. Water samples were collected from ten stations monthly over six months spanning wet and dry season conditions. Parameters analysed include temperature, pH, dissolved oxygen, biochemical oxygen demand, turbidity, nitrate, phosphate, total coliform, faecal coliform, and concentrations of chromium and lead. Results reveal a consistent pattern of quality degradation at stations immediately downstream of Makurdi urban settlements compared to upstream reference stations, with dissolved oxygen declining from 7.2 to 3.8 milligrams per litre between the upstream and most impacted downstream stations. Biochemical oxygen demand at downstream stations averages 28 milligrams per litre, far exceeding the WHO guideline of five milligrams per litre for safe surface water. Faecal coliform counts downstream of the main abattoir discharge point reach 12,000 colony forming units per 100 millilitres. Seasonal analysis shows greater contamination severity during the dry season when dilution capacity is reduced. The study recommends construction of a functional municipal wastewater treatment plant and improved abattoir waste management. Keywords: river water quality, Benue River, urban pollution, wastewater, Makurdi.