India: Nagaland University urges action against pollution of Dhansiri River

Nagaland University researchers have completed a comprehensive seasonal assessment of water quality in the Dhansiri River, one of the major waterways in Northeast India. The study, conducted at three points along the river (upstream, midstream, and downstream), measured 16 physicochemical indicators and calculated the Water Quality Index (WQI) using the Weighted Arithmetic Index method. It found that water quality sharply deteriorates in summer, with total dissolved solids (TDS), biochemical oxygen demand (BOD), and total alkalinity levels exceeding national and WHO standards. Winter eases pollution levels, although contamination remains an all-year issue. According to Dr M Romeo Singh from the Department of Botany, who led the research, river pollution is caused by unchecked urban and agricultural discharge, improper waste dumping, and poor drainage, especially in downstream areas.
To revive the Dhansiri River, researchers suggested relocating dumping zones away from the waterway, banning direct trash discharge, and upgrading wastewater treatment and drainage infrastructure. They also recommended to conduct regular water monitoring and community awareness campaigns. Dr Sing said the study sets a model for restoring the Dhansiri and other neglected waterways, helping to develop evidence-based restoration strategies. He also urged further research into biological indicators, heavy metal contamination, and emerging chemical pollutants.