Dhaka City has been suffering from significant challenges related to river pollution. The rivers encircling Dhaka—namely the Buriganga, Turag, Shitalakkhya, Balu, Tongi Canal, and Dhaleswari—are experiencing severe pollution, which has escalated alarmingly in recent years.
Industrial waste is one of the primary contributors to this pollution. The degradation of these rivers' water quality has reached a point where it poses significant challenges to water treatment facilities. The Sayedabad Water Treatment Plant, which relies on the Shitalakkhya River, faces difficulties in treating water due to excessive pollution, especially during the dry season. Approximately 1.5 million cubic meters of waste are dumped into Dhaka's surrounding rivers daily, with industrial sources accounting for about 80% of this pollution.
Climate-resilient green industries present a promising pathway to combat the river pollution issue. By integrating sustainable practices and technologies, these industries can reduce water pollution and promote the efficient use of resources.
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How Industries Cause River Pollution in Dhaka City
Industries are one of the biggest contributors to river pollution in Dhaka. The pollution primarily comes from textile, dyeing, tanneries, pharmaceuticals, and chemical industries that discharge untreated or poorly treated wastewater into rivers. Here’s how industries are causing severe pollution in Dhaka’s rivers:
Direct Discharge of Industrial Wastewater
Many industries in Dhaka, especially in areas like Savar, Gazipur, Narayanganj, and Keraniganj, discharge toxic chemicals, heavy metals, and untreated wastewater directly into rivers. These wastes include dyes, acids, alkalis, and heavy metals (lead, chromium, arsenic, and cadmium) that degrade water quality and harm aquatic life.
Textile and Dyeing Industry Pollution
The textile and dyeing industries in Dhaka (particularly in Narayanganj and Gazipur) use large amounts of water and produce chemical-laden effluents. These wastes contain synthetic dyes, bleaching agents, and salts, making river water toxic and depleting oxygen levels.
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Tanneries in Hazaribagh and Savar
The leather industry, previously concentrated in Hazaribagh, was relocated to Savar Tannery Estate to reduce pollution. However, the central effluent treatment plant (CETP) in Savar is not fully functional. As a result, untreated tannery waste containing chromium, sulfides, and acids still pollutes the Dhaleshwari River, turning it black and lifeless.
Pharmaceutical and Chemical Industry Waste
Factories producing medicines, pesticides, and plastics release toxic organic compounds into rivers like the Turag and Shitalakkhya. These chemicals can cause long-term health hazards for people using river water.
Lack of Proper Wastewater Treatment
Many industries do not have Effluent Treatment Plants (ETPs), or they bypass them to save costs. Even when ETPs are installed, they often operate below capacity or remain inactive due to poor enforcement of environmental laws.
Contribution to Heavy Metal Contamination
Heavy metal contamination is another critical concern. A comprehensive study published in July 2024 highlighted alarming levels of heavy metals—such as arsenic, lead, cadmium, chromium, iron, and manganese—in Bangladesh's rivers over the past two decades.
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The Buriganga River was identified as the most polluted, with contamination levels exceeding acceptable limits during all three seasons, posing severe threats to aquatic life and public health.
Impact on Aquatic Life and Public Health
Industrial pollution has drastically reduced fish populations in Dhaka’s rivers. Contaminated river water enters the food chain, affecting humans through the consumption of fish and polluted water. People living near polluted rivers suffer from skin diseases, respiratory issues, and gastrointestinal disorders.