Water Quality Assessment of a College Stream: Implications of Microbial Diversity on Ecosystem Health

This research presents a comprehensive assessment of water quality and microbial
diversity in a college stream impacted by anthropogenic pollution. Five sites were sampled (including an upstream control site and four downstream sites having different levels of pollution exposure) to gather the required water samples. Physicochemical parameters (pH, dissolved oxygen, turbidity, bio-chemical oxygen demand, nutrient levels), microbial indicators (total coliforms, fecal coliforms, Escherichia coli, heterotrophic plate counts and fungal diversity) were measured on the basis of the standard EPA and APHA methods. Results demonstrated significant deterioration in water quality at polluted sites compared to the control: fecal coliform concentrations reached 180 CFU/100 mL (Site 3: garbage accumulation), compared to 0 CFU/100 mL at the control site. Dissolved oxygen levels declined from 8.3 mg/L (control) to 2.1 mg/L (most impacted site). Algal cells increased from 8.5 × 10³ cells/mL (control) to 72.8 × 10³ cells/mL (most impacted site), indicating nutrient enrichment. The microbial test revealed the presence of the species of Euglena and Aspergillus species as the dominant organism in contaminated areas, and a high concentration of fecal indicator bacteria. It was partially recovered at the downstream site indicating that it had some ability to self-purify. Such results highlight the urgency to manage sources of pollution and introduce programs of integrated monitoring of water quality and restoration of an ecosystem.