THE relocation of tannery units from Hazaribagh in Dhaka to the capital鈥檚 outskirts of Savar appears to have been little more than a relocation of pollution. The move was largely prompted by criticism of the unabated contamination of the River Buriganga. But, the pollution burden is now borne by the River Dhaleshwari. In the absence of a proper, adequate waste management at the BSISC Tannery Industrial Estate, much of the waste is haphazardly dumped directly into the river or on the riverbank, which has degraded the river鈥檚 water quality, destroyed its aquatic life and biodiversity, and posed health risks to communities and tannery workers. A University of Dhaka study, published in the Bangladesh Academy of Science journal, shows alarming levels of heavy metals and microbial contamination in the river. The study found pathogenic organisms, including Escherichia coli, at 150 colony-forming units per millilitre, far above the World Health Organisation standard of zero CFU. It also detected lead concentration of up to 0.07mg per litre, nearly five times higher than the WHO limit of 0.015mg while chromium was found at 0.1mg per litre, the upper threshold of safety.
The study observes that what now happens to the Dhaleshwari marks the early stage of a contamination cycle that could haunt communities for generations. At the centre of the crisis lies the central effluent treatment plant, which is not capable of treating the volume of waste produced by the estate. The facility was designed to process 25,000 cubic metres of effluent daily, but its effective capacity is only 14,000 cubic metres while tannery output exceeds 30,000 cubic metres during peak seasons. The plant lacks crucial features such as reverse osmosis technology for salt removal, an integrated grease system and a sedimentation tank. It also does not have the capacity to process the daily output of chromium waste. Its three chrome recovery units can process only 1,050 cubic metres of chromium waste whereas the daily output is about 5,000 cubic metres. Moreover, local storage depots outside the estate and the haphazard dumping of solid tannery waste, including chromium-contaminated sludge, on the riverbank, continue to aggravate the situation. It is feared that toxic leachate could seep into the groundwater. Beyond the Dhaleshwari, other rivers and water bodies at Savar are also choked with the unplanned and chaotic disposal of industrial and municipal wastes.
The tannery estate authorities should, therefore, immediately and earnestly attend to waste management so that the estate does not become a curse for the river, water bodies and the people. The government should, meanwhile, address the growing pollution crisis that Savar, a key industrial belt, continues to suffer from.
