Assessment of Surface Water Quality in Opuoko Town, Khana LGA, Rivers State, Nigeria

Abstract

The general aim of this study was to assess the quality of surface water in a selected location in Opuoku, Khana Local Government Area of Rivers State. The study determined the extent to which human activities affected the quality of surface water. Water quality analysis was performed for 13 parameters ranging from physicochemical properties and heavy metals at up-stream depth, mid-stream depth, and down-stream depth – The dissolved oxygen levels were assessed using the streeter-Phelps equation to evaluate the water quality and to ascertain whether the water is within the acceptable standard set by World Health Organization (WHO). The result from the present study indicated that all the parameters were within the permissible limits, with the exception of Total Suspended Solids (TSS), Cadmium(Cd), and Lead (Pb). This necessitates the need to address the pollution sources, ensure regulatory compliance, assess the environmental impact, and provide a water treatment plant. The results from this physicochemical analysis showed variations in the parameters at different intervals along the watercourse signifying potential anthropogenic and natural influences. The range of results from downstream to upstream are as follows; Total Suspended Solid (100mg/L to 300mg/L), Total Dissolved Solid (4.0mg/L to 13.0mg/L),  Electrical Conductivity (9mS/cm to 52mS/cm), Iron (-0.189mg/L to -0.006mg/L), Lead  (Nil to 0.146mg/L), Cadmium (0.149mg/L to 0.037mg/L), Chloride ion (2.42mg/L to 7.37mg/L), Alkalinity(0.15ml to 0.5ml), Dissolved oxygen (5.8mg/L to 5.4mg/L), Biochemical Oxygen Demand (1.3mg/L to 0.4mg/L), and Chemical Oxygen Demand (122.8mg/L to 152.3mg/L). Dissolved oxygen levels/deficit evaluated using the streeter-Phelps model over 8meters of the watercourse from upstream to downstream is approximately -0.308 mg/L. This indicates a decrease in dissolved oxygen concentration as you move from upstream to downstream, which is typical in water bodies with organic matter degradation. This research endeavours to offer significant insights into the water quality at Opuoko, shedding light on its implications for community access to safe water and the preservation of the local aquatic environment. Emphasizing the critical need for ongoing monitoring and effective water management, it underscores the importance of safeguarding clean and secure water resources in the region.