Dhaka, a mega city that home to about 14 million people, may face acute safe water shortage in the days to come due to unchecked water pollution in the rivers around the capital. The Dhaka Water Supply and Sewerage Authority (Dhaka Wasa) has undertaken to supply 70% of its water from surface water sources to the city by 2020. This may not be possible if the destruction of the Dhaka watershed continues at its current pace.
Six rivers – the Buriganga, Sitalakhya, Bangshi, Turag, Balu and Dhaleshawri – flow around the city, and form the Dhaka watershed. But the highly contaminated water of these rivers is no longer suitable for human consummation.
A new study by the Dhaka-based think tank Plasma Plus Application and Research Laboratory, funded by the World Bank, found that the highly contaminated water of the six rivers surrounding the city cannot be treated using the traditional approach that the Wasa has used – particularly during the dry season. Persistent organic micro-pollutants and heavy metals are emerging in surface water while the excess use of nitrogenous and phosphate-based fertilisers and agricultural runoff is also heavily polluting surface water sources. “In this situation, the water quality testing laboratories are under increasing pressure to improve their analytical capacity because of the diversified of emerging pollutants in surface water,” the study added.
The presence of organic micro-pollutants and non-degradable heavy metals is particularly worrisome, because it makes the water untreatable by conventional means, the chief investigator of the study, Amir Hossain Khan, told thethirdpole.net.
Abu Saleh Khan, deputy executive director of the Institute of Water Modelling (IWM), said water of the city’s surrounding rivers could not be used unless industrial pollution is checked.
Rising dependence on transboundary rivers
According to official sources, Dhaka Wasa currently draws about 78% of its water through groundwater extraction to meet city dwellers’ water demand while the remaining 22% comes from surface water sources. At present, Dhaka Wasa has a capacity of producing 2,420 million litres of water daily against the current demand of about 2,350 million litres. And the demand of water will go up in the future.
Against the backdrop of the rapid decline of the groundwater level in the capital, Dhaka Wasa has taken steps to increase dependence on surface water sources by bringing water from transboundary rivers – the Padma (known as the Ganga in India) and the Meghna – since the water in the rivers surrounding the cities is not suitable to drink even after treatment.
Chief engineer of Dhaka Wasa, M Shahid Uddin, said that the Padma (Jashaldia) Water Treatment Plant is currently being constructed at a cost of BDT 35 billion (USD 442 million) with financial support from the Chinese government. Once the project is implemented, it will produce 450 million litres of water daily that will be supplied to city dwellers.
Dhaka Wasa has also received financial support from the Asian Development Bank (ADB) to set up infrastructure to bring water from the Meghna River that will be treated at a water treatment plant to be set up in the city’s Khilkhet area. The plant will be capable to produce 500 million litres of water daily.
“As the government has failed to control water pollution of Dhaka surrounding rivers, the authorities concerned have no alternative options to bringing water from further away,” said Abu Saleh Khan.
Amir Hossain Khan said bringing water from the Meghna River to ensure drinking water supply to the capital may not be sustainable solution in long-run unless pollution in the upstream rivers around the city is checked.
Poor urban water governance
Amid growing water challenges, the country’s industrial growth has continued since independence in 1971. Most of the country’s factories and industries are set up on the banks of rivers so that their chemical waste and contaminated water is dumped straight into the water. Similarly, a huge number of industries built on the banks of the six rivers around Dhaka city are polluting the rivers in the absence of proper monitoring of the authorities concerned.
“There are around 7,500 industries on the banks of Dhaka surrounding rivers. And these industries are indiscriminately releasing chemical wastes into water-bodies and rivers,” said MA Matin, the general secretary of Bangladesh Paribesh Andolan (Bapa).
Saleh Khan said these industries are supposed to install effluent treatment plants (ETPs) to check water pollution, but the owners of these industries skip this to minimise their production costs and thus release untreated water to rivers.
He said there are many good laws in the country to protect environment, but there is no proper implementation, allowing pollutors to contaminate water of the country’s rivers.
Matin said if the authorities concerned want to restore the water quality of the rivers that surround Dhaka, they must ensure navigability of these rivers by evicting encroachers, dredging and checking pollution of industries. Unfortunately there seems to be little hope in this regard. Recently at a seminar the Water Resources Minister, Anisul Islam Mahmud, told the audience that he was “helpless”, and they needed to raise a united voice against the people who are polluting rivers.
Quazi Sarwar Imtiaz Hashmi, additional director general of the Department of Environment (DoE), said the department is trying its best to check water pollution through strengthening enforcement and monitoring. “The Prime Minister (Sheikh Hasina) is committed to protect environment… but the people who pollute water are so powerful and influential,” he added, suggesting that even the Prime Minister was helpless before the polluters of the city.