Access to safe drinking water due to microbial and chemical contamination remains a major public health challenge in many developing countries. This study assessed the microbiological and physicochemical quality of tap and borehole water sources within Umaru Sanda Ahmadu College of Education, Minna, Nigeria. A total of 25 water samples were collected from five sampling locations and analyzed using standard microbiological and physicochemical procedures. The results revealed substantial microbial contamination across all sites, with total coliform counts ranging from 28.3 to 40.0 CFU/100 mL, exceeding the recommended drinking water standards. Pathogenic organisms, including Escherichia coli, Salmonella typhi, and Klebsiella pneumoniae, indicating fecal contamination and potential health risks were identified. Physicochemical analyses showed variations in dissolved solids, conductivity, nutrients, and heavy metals across sampling sites. Bio-augmentation using beneficial microbial strains significantly reduced microbial loads, nutrient concentrations, and selected heavy metals, including iron, copper, and lead. Probiotic isolates, particularly Lactobacillus acidophilus and Lactobacillus bulgaricus, exhibited strong antagonistic activity against the identified pathogens. The findings indicate that water sources within the institution require urgent attention and highlight bio-augmentation as an environmentally friendly and sustainable remediation strategy for improving water quality.