A study conducted by Wasa claims that the water quality of six rivers around Dhaka has been polluted to the extent that they are unusable for humans, aquatic lives and industry.
The study, titled “An Analytical Study of the Pollution Profile of the Major Rivers around Dhaka City” was conducted by Plasma Plus Application and Research Laboratory on behalf of Dhaka Wasa and financed by the World Bank.
Amir H Khan, leader of the study team, said: “The current state of water quality of the surrounding rivers of Dhaka is the ultimate result of extreme pollution.
“The government should take appropriate measures to check the pollution urgently, otherwise it will be tough to meet the growing demand of capital's rising population."
Pollution is so severe in the Buriganga, Shitalakkhya, Dhaleshwari, Turag Bongshi and Balu rivers that it is almost impossible to treat the water and make it suitable for humans, the study says.
Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD) are the majors among the 12 parameters of water quality measurement of any surface water. Both of these parameters in the six rivers are far away from the acceptable level.
For instance, Department of Environment (DoE) sets the standard level of DO in the water as 6 mg/litre but none of the six river's water ever came close to the standard during the entire study period.
In case of BOD, all of the rivers’ water shows the level above 2mg/litre, the maximum level for potable water.
The findings of the study were presented at a seminar at CIRDAP auditorium on Sunday.
Dhaka Wasa is responsible for supplying safe drinking water for the capital’s 17m residents. Against the daily demand of 250-300 crore liters of water in Dhaka city, 78% is supplied by extracting groundwater while the remaining 22% is supplied after treating the water of the surrounding rivers.
The study was conducted after collecting water samples from 10 separate points of each river with 2km distance between the closest points, from April to December in 2015.
Syeda Rizwana Hasan, chief executive of Bangladesh Environmentalist Lawyers Association (Bela) blamed indiscriminate discharge from industries including tannery effluents for the horrible conditions of the rivers, and condemned the government for siding with the errant industries instead of trying to save the environment and the ecology.
Citing the example of Hazaribagh tannery, she said: “The tannery industry destroyed the river Buriganga but the government has been trying to compensate them for relocation, instead of penalising them.”