Being the capital of a riverine country Dhaka is blessed with rivers around it. Actually, the city was built and became paramount due to these rivers. Ironically, these rivers have not only lost their glory but are also becoming a heavy liability upon the city.
Dying rivers
The sources of most refreshing water has become bodies of toxic sludge. 110 square kilometre area of the Shitalakkha, the Turag, the Balu and the Dhaleshwari – the surrounding rivers of Dhaka – is being continuously polluted by the contamination of tannery situated in Hazaribag.
A decade earlier, the government took initiatives to relocate tanneries and apporved a “tannery town” in Hemayetpur of Savar at a meeting of Executive Committee of Economic Council on August 16, 2003. It was supposed to be completed by 2005 but the time was extended for five more years and then another two more upto 2012.
Despite extension of the schedule thrice, the work is yet to be finished. According to the Department of Environment (DoE), 20,000 tonnes of tannery waste, including some highly toxic materials, are released into the river every day.
Apart from tannery there are many more big and small industriues in the bank of these rivers. Most of them do not have proper ETP (effluent treatment plant) and they do not follow even the basic laws regarding the protection of rivers.
Experts identified nine industrial areas in and around the capital city as the primary sources of river pollution: Tongi, Tejgaon, Hazaribagh, Tarabo, Narayanganj, Savar, Gazipur, Dhaka Export Processing Zone and Ghorashal. Most of the industrial units of these areas have no sewage treatment or ETP plants of their own.
Although the Water Act 2013, River Protection Act 2013, the Environment Conservation Rules 1997 have provision of punishment, they are evaded by corruption, political muscle and the lackluster role of River Commission and other authorities.
Back in 2009 the High Court directed the government to demarcate river banks, but that is not yet implemented. That is related to another huge problem – the encroachment of rivers. The problem is severe for these rivers and the pollution is optimum for encroachment.
Dumping grounds
One of the most crucial issue is the sewerage management of the city. A city of 344 square kilometres with more than 15 million inhabitant the function is humongous; amazingly there is no proprer sewerage management system.
In the capital, everyday 9000 tons of waste is produced; 49% of them are from households and the rest from commercial, industrial and medical. Only about 5-6% of the waste is recycled despite the presence of technology and manpower. Hasin Jahan, program director of Wateraid, Bangladesh said less than one-fourth of Dhaka city area is currently under the coverage of sewerage network.
In Dhaka, where there is no sewerage network, more than half of the buildings do not have any septic tank and the sewer pipelines of these buildings are directly connected either to the open drain or to the storm drainage system polluting the surface water and the environment.
Apart from that, the solid waste produced here daily is disposed directly into the rivers without treatment. A recent Asian Development Bank (ADB) research published that, by 2015, the city dwellers will generate 8000 tons solid waste that needs a 292-hectare land for management, which is not possible.
Possible solutions
Recycling the waste would be a possible way for management, said Hasin Jahan. Bangladesh uses around 3.5 million tons of fertiliser every year, of which about 2.6 million tons are imported. Government provides subsidy of around Tk18 per kg of fertilisers to the farmers.
Hypothetically, if we could convert the entire amount of sludge produced in the country into proper fertiliser, we would get upto 3 million tons. Bangladesh can save an estimated amount of Tk5,000 crore per year. Even if we could utilise a certain percentage of this potential, it could be a huge gain for the country.
This should not be considered from monetary perspective only; use of this manure will improve soil texture and environment. It will save the treatment cost for turning polluted water into standard drinking water at water treatment plants by not polluting surface water. This is one of the propositions to managing the sludge.
At the same time, environment specialist Engineer Nasir Uddin Khan, based on UK, commented about the present scenario of water pollution due to the sewage waste in Dhaka city. He said any kind of action taken for human waste management would help in the rivers getting back their life.
Back in the days, river water or any other source of surface water was used for drinking and cooking purposes. But, nowadays, the odor of the Buriganga river water makes one think it is a waste dumping zone rather than a river. It cannot be cleaned by penalising industries situated on the bank of rivers. That is not the permanent solution.
Those industries have the ETP, but they don’t use it all the time. If they are bound to construct CETP (common ETP), then individuals cannot make the decision of not using ETP. And that way, industrial waste-water can be treated. At the same time, the waste collection process would develop, and then the generated human waste can be recycled to energy.
He also blamed RAJUK for developing an unplanned sewage system in this city. If authorities can take action to separate the solid waste by improving the design of the sewage lines, the rivers can be saved. That way, the condition of surface water would improve for use.
Time to act
All know that water supply of Dhaka city is heavily dependent on groundwater extraction; more than 87% of the supplied water is being extracted from this source and the rest amount from rivers. Such extensive dependency enhances a very high depletion rate of groundwater table.
A research from Unnyan Onneshan published that Dhaka city has been experiencing a sharp decline in groundwater table with more than 20-meter fall during the last seven years at a rate of 2.81 meter per year (m/y). Considering the existing depletion rate, the study predicts that the groundwater table will go down to 120 meters by 2050.
To solve this problem of water crisis and at the same time to protect the surrounding rivers, now is high time to take action for improving the sewerage system and redo the urban planning. Though the master plan of Dhaka Water and Sewerage Authority (DWASA) proposed construction of sewerage network and treatment plants, the divisional towns and municipalities have no plan on how they would manage fecal sludge.
Master plans for few small towns are in development process; but these do not have any specific proposition for fecal sludge management, said Hasin Jahan. However, implementation of any master plan in terms of its investment, timeline and other factors are pretty uncertain.
There must be proper work distribution among DWASA, RAJUK and Dhaka City Corporation. Right now more than 5 million people are directly facing the danger of water pollution in Dhaka. This number will virally increase if quick steps are not taken