Toxic black waste from industries, factories and nearby residential areas in Chattogram is entering the Halda River through the Katakhali and Bamanshahi canals, according to the report published on July 26, 2026. Monsoon and floodwater are mixing with the waste, turning the river’s clear water dark and black. The pollution is described as a serious threat to brood fish, dolphins, the aquatic environment and biodiversity in the river, identified in the report as Asia’s only natural fish breeding ground.

Residents said foul odours from the black water have made movement difficult in Shikarpur and the Madunaghat Kuwaish College area, while people are suffering from various illnesses. The pollution is occurring during the April to June-July spawning season for brood fish. Egg collectors along the riverbank warned that the Halda could face conditions similar to the Buriganga if the situation continues.

Local residents said industrial and household waste from Bahir Signal, Oxygen and Kulgaon reaches canals through drains before flowing into the river. Professor Dr Manjurul Kibria called for protecting the Halda from toxic waste. The report also cited unplanned sluice gates and embankments across 36 tributary canals, rivers and streams as obstructing natural flow.