Physicochemical and Bacteriological Assessment of Treated and Untreated Water from Ahmadu Bello University Zaria Water Treatment Plant

Background and Objective: Water sources, whether surface or groundwater, are increasingly exposed to contaminants due to anthropogenic activities. Assessing the quality of water from the Ahmadu Bello University (ABU) Zaria Water Treatment Plant is essential to ensure its safety for drinking and recreational purposes. This study aimed to evaluate the physicochemical and bacteriological properties of treated and untreated water from the plant, assessing the efficacy of the treatment process in meeting international water quality standards. Materials and Methods: Water samples were collected from both treated and untreated sources at the ABU Zaria Water Treatment Plant. Physicochemical parameters analyzed included pH, temperature, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), alkalinity, chloride, nitrate, and phosphate. Bacteriological analysis focused on total coliform counts and the presence of specific pathogens such as E. coli, Klebsiella sp., and Proteus sp. The data were analyzed using descriptive statistics, and significance was tested (p>0.05). Results: Both treated and untreated water samples met the WHO pH standards (8.07-8.12). Temperature remained within ambient levels. Treated water exhibited higher EC (228.33 μS/cm) and TDS (114.17 mg/L) compared to untreated water (168.67 μS/cm and 84.17 mg/L, respectively). DO levels were significantly higher in treated water (2.28 mg/L) than in untreated water (0.93 mg/L). The BOD was lower in treated water (1.18 mg/L) compared to untreated samples (0.47 mg/L), indicating effective reduction of organic matter. Alkalinity, chloride, nitrate, and phosphate levels showed minimal variation between treated and untreated samples. Total coliform counts were substantially reduced in treated water (0-7) compared to untreated water (31-65). Despite treatment, E. coli, Klebsiella sp., and Proteus sp. were still detected in some samples. Conclusion: The treatment process at ABU Zaria Water Treatment Plant effectively improves most physicochemical and bacteriological parameters, aligning with WHO standards. However, the detection of pathogenic bacteria in treated water highlights the need for further enhancement of treatment protocols to ensure complete safety for human consumption.