Abstract
Water treatment processes involved in any surface water treatment plant has a direct effect on the quality of final treated water produced from the plant. This study is a comparative assessment of the overall efficiency of the New Ahmadu Bello University Water Treatment Plant (NABUWTP) and Old Ahmadu Bello University Water Treatment Plant (OABUWTP) treatment processes. Water quality parameters for water fit for drinking were evaluated with respect to World Health Organization (WHO) and Nigeria drinking water standards. The NABUWTP average Turbidity (1.4 NTU), pH (7), Electrical Conductivity (206.9 µS/cm) and Temperature (25.50C) as compared to the OABUWTP average Turbidity (2.4 NTU), pH (6.5), Electrical Conductivity (105.9 µS/cm) and Temperature (26.60C) are satisfactory for final treated water qualities except Residual Chlorine: 0.02 mg/l and 0.04 mg/l for NABUWTP and OABUWTP respectively which are below acceptable standard. The NABUWTP presently produces 1000 m3 of potable water in 18 hours (0.015 m3/s) and the OABUWTP produces 3876 m3 per day (0.045 m3/s). Bacteriological analysis of the final treated water in both plants revealed 0-0-0- cfu/100 ml sample coliform count which satisfies the requirement for ensuring a pathogen free water. The OABUWTP was found
inconsistent in it operations resulting from Performance Limiting Factors such as: Inordinate quantity of Alum, Lime and Chlorine used, Insufficient water certified staffs, Unavailable flow measuring devices, Flash mixer at the flocculation chamber and Lack of chemical feed equipment. A Comprehensive Technical Assistance (CTA)/ Optimization exercise is needed at the OABUWTP due to it inconsistencies in performance. The NABUWTP (33.3%) has an overall average better performance compared to the OABUWTP (31.3%).

Key words: Treatment process, water standards, water plant, pathogen