Longitudinal Assessment of Physicochemical and Microbial Water Quality along the Ganga River Continuum: Linking Anthropogenic Activities to Pollution Gradients

What is it about?

The research article, “Longitudinal Assessment of Physicochemical and Microbial Water Quality along the Ganga River Continuum: Linking Anthropogenic Activities to Pollution Gradients,” investigates how human activities influence water quality from the glacier-fed source at Gaumukh to the estuary at Gangasagar. The study collected 18 surface water samples between November 2024 and January 2025 and evaluated physicochemical parameters (pH, turbidity, total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD)) along with microbiological indicators, including Total Coliform (TC), Faecal Coliform (FC), and Faecal Streptococci (FS). The results revealed a clear longitudinal deterioration in water quality from the upper Himalayan region to the densely populated middle and lower stretches of the river. The upper stretch, particularly Gaumukh and Gangotri, exhibited excellent water quality with low turbidity, low organic pollution, and no detectable faecal contamination. In contrast, the middle stretch, especially Kanpur, Prayagraj, and Varanasi, showed the highest pollution levels because of untreated municipal sewage, industrial effluents, agricultural runoff, and religious activities. Increased TSS, BOD, and COD values reflected rising organic and industrial pollution, while elevated microbial counts indicated serious faecal contamination and potential public health risks. Phenotypic characterization demonstrated a shift from predominantly Gram-positive bacteria in the pristine upper reaches to Gram-negative, sewage-associated bacteria downstream, confirming the influence of anthropogenic activities on microbial community composition. Overall, the study identifies the middle Ganga as the principal pollution hotspot and recommends strengthening wastewater treatment, regulating industrial discharges, and implementing continuous basin-wide monitoring to restore river health and protect ecosystem integrity and human well-being.

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Photo by Rishabh Gagneja on Unsplash

Photo by Rishabh Gagneja on Unsplash