THE EFFECTS OF SEWAGE EFFLUENT DISCHARGES ON THE WATER QUALITY OF WUPA RIVER IN ABUJA, NIGERIA

Abstract

The effect of sewage effluents discharge on water quality of the receiving river in the Wupa area of Abuja was studied to determine the assimilative capacity of the receiving river in event of shock load due to treatment plant failure. The river passes through Idu industrial area of Abuja from where effluent from Wupa sewage treatment plant is discharged. Water samples were taken from six stations along the river reach of 16 kilometres within the vicinity of the treatment plant. Both the effluents and the water samples at six selected points along the river were analysed for pH, electrical conductivity (EC), turbidity, biochemical oxygen demand (BOD) and dissolved oxygen (DO). The results were compared with the standards set by National Environmental Standards and Regulations Enforcement Agency (NESREA) for waste water. The result indicates that the BOD load on the river was within the stipulated limit and there exist a moderate degree of self-purification in the river. The study concluded that the river can withstand BOD shock loadings of up to 44.3 mg/L from the treatment plant without injuring the assimilative capacity of the river. INTRODUCTION Water quality monitoring forms an important component of managing the water quality of a river in terms of assessing the health conditions of that river in order to ensure a healthy aquatic environment. Certain water quality indicators such as dissolved oxygen (DO), temperature, biochemical oxygen demand (BOD) etc, need to be determined and compared with specified