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.