The dumping of untreated industrial waste into the Turag in Tongi goes unabated. Inset, the dark purple water shows how heavily the river has been contaminated with chemical waste. Photo: Anisur Rahman

Pollution taking its hefty toll

Environment dept drives could do little as untreated industrial, human wastes continue to flow in to rivers of poison

Pinaki Roy

A large swathe of the Buriganga river, the lifeline of the capital, has turned pitch-black with toxic waste flowing into it from industrial units. Oblivious of health hazards, a few children dive into the stinky water.

"Look at the colour of the water. Our children bathe in it. We have no option but to use this water," said Kamal Mia, a slum dweller at Posta in Kamrangirchar.

Untreated liquid waste from Hazaribagh tanneries continues to stream into the river. Dhaka Water Supply Authority (Wasa) collects this stinky pitch-black water, then treats and supplies it to city residents.

However, specialists and scientists have long been warning that surface water in Dhaka has become untreatable for drinking.

A French expert at Sayedabad treatment plant said Buriganga water is too polluted to be treated for drinking round the year, except for a couple of months during the rainy season.

"We are supposed to run a water treatment plant, not a waste management plant," he told The Daily Star at a recent programme.

Industrial pollution continues unabated despite commitments from political parties and High Court directives to save rivers from contamination.

Moreover, Wasa never took any effective steps to stop dumping of human waste into the river.

City residents are compelled to use stinky and unsafe pipe water since rivers around the capital continue to be used as dumping sites for liquid waste from residential and industrial areas.

In December last year, the Department of Environment collected samples from five different points of the Buriganga to find out the quality of its water.

Laboratory analysis of the samples shows presence of dissolved oxygen between 0.5 and 0.84 mgs per litre against the standard 5 mg/L for maintaining aquatic life in surface water in Bangladesh.

Besides, pH, a measure of acidity, was between 7 and 7.5 while the standard is 6.5.

In 2007, researchers of Bangladesh University of Engineering and Technology found that oxygen level was at 0.25 mgs/L in river water at Chadnighat point, 0.27 mgs/L at Norai near Trimohini, and 0.27 mgs/L in the Turag in Tongi before the monsoon.

But oxygen level rose to 0.7 mgs/L at Chadnighat point, 0.63 mgs/L at Norai, 0.63 mgs/L in the Turag after the monsoon.

A three-year research found that some invertebrates and small organisms come to life in these rivers when water flow increases in the rainy season. But these life forms disappear in the dry season.

The Institute of Water Modelling and the World Bank conducted a study on pollution in Dhaka rivers in 2007. It showed more than 300 effluent discharge outlets in the capital and Narayanganj.

DoE officials said more than 300 major industrial units are still dumping liquid waste into rivers.

Most industries do not have treatment plants, and even the ones with such plants often refrain from using them to save operational costs.

This correspondent found many industries discharging untreated liquid waste directly into rivers in June.

Dyeing and printing industries including Hossain Dyeing and Printing Manufacturer Pvt Ltd, Everyway Yearn and Dyeing, and Merchant Plastic on the bank of Tongi canal were found discharging untreated liquid waste into the river.

The water was pitch-black and stinky from Trimohini up to Munshiganj and from Basila up to Fatullah, Narayanganj. Many people, particularly those in slums on river banks, were using the river water for household purposes.

Unabated river pollution forced Wasa to depend more on underground water to maintain supply to city residents, causing depletion of underground water at an alarming rate. Of over 210 crore litre water supplied by Wasa, nearly 87 percent comes from underground and the rest from surface water.

Wasa officials at a recent seminar said they need about Tk 10,500 crore to set up five more water treatment plants to treat and supply drinking water.

Wasa plans to increase collection of surface water from present 13 percent to 70 percent by the next 10 years.

For over 13 million people in the capital, only one sewage treatment plant is there in Pagla for treating household waste. The plant treats sewage of only 20 percent of the city population.

Effluents of Hazaribagh tanneries, dyeing and other factories along with human waste flow into rivers through Wasa storm sewers.

On assumption of office, the present government implemented a Tk 21 crore Buriganga-Turag River Cleaning Project. But the rivers remain polluted as the sources of contamination could not be plugged.

A wide outlet empties household and industrial waste onto the Shitalakkhya about a kilometre south of Kanchpur Bridge in Narayanganj. Photo: Anisur Rahman