An Appraisal of Indices of Eutrophication of Surface Water of Some Parts of River Benue in Makurdi Metropolis, North-Central, Nigeria

Physical, chemical and biological parameters of surface water (river Benue) Makurdi, were evaluated to determine the eutrophication potential and make logical inference on the fate of surface water system. Sampling was from five (5) strategic sites along river Benue and standard methods were used for the measurement of nitrate, phosphate, biological oxygen demand, chemical oxygen demand, pH, conductivity, total dissolved oxygen (TDS), potassium and algae count as indices of eutrophication. The results showed low levels of nutrients and microbial activities. The values of some eutrophication parameters in the sites were as follows: BOD mg/L (Coca-Cola 0.30±0.00, Kyabis hotel 0.43±0.03, Wadata 0.88±0.03, Abattoir 0.90±0.10, BSU 0.62±0.03). Nitrate mg/L (Coca-Cola 1.86±0.13, Kyabis hotel 0.73±0.03, Wadata 0.68±0.05, Abattoir 0.40±0.03, BSU 0.89±0.04). Phosphate mg/L (Coca-Cola 0.04±0.00, Kyabis hotel 0.05±0.00, Wadata 0.05±0.00, Abattoir 0.08±0.00, BSU 0.05±0.00). Findings revealed that many of the eutrophication parameters studied were within threshold levels, as they were within permissible limits of the World Health Organization and Standard Organization of Nigeria, and therefore the river is not under immediate threat of accumulation of phytoplankton and nutrients. However, traditional practice of dumping of wastes into water bodies must be reversed to ensure the river does not become eutrophicated in the nearest future.