Bangladesh has about 230 small and large rivers and its 140 million people depend on them for a living and transportation. But many of them are drying up or are choked due to pollution and encroachment. The Buriganga River is one of them which flow past the southwest outskirts of Dhaka city, a capital of Bangladesh with 12 million people, which largely depends on the Buriganga River’s water for drinking, fishing, carrying merchandise and transportation. The untreated wastes, domestic and industrial, clinical, pathological being released into the Buriganga River and this tendency is increasing day by day. The reality is that, the river, now, has become a dumping ground of kinds of solid, liquid and chemical waste. These activities have caused narrowing of the Buriganga and disruption of its normal flow of water.The pollutants have eaten up all oxygen in the Buriganga which is called biological dead. There is no fish or aquatic life in Buriganga apart from zero oxygen survival kind of organisms. In this study we want to discuss about history, causes, states, impacts of Buriganga pollution and finally the way to mitigate or minimize the pollution of Buriganga River.
History of Buriganga River
In the distinct past, the river Buriganga knew as “Old Gange” was famous during the Mugals period when they made Dhaka as capital in 1610, the banks of the Buriganga were already a prime location for trade.In a couple past, a course of the Ganges river used to reach the Bay of Bengal through the Dhaleshwari river. When this course gradually shifted and ultimately lost its link with the main channel of the Ganges it was renamed the Buriganga. It is said that the water levels during high and very high tides in this river astonished the Mughals. In the 20th century the water table and river became polluted by polythenes and other hazardous substances from demolished buildings near the river banks. The course of the Padma, as the main course of the Ganges is known in Bangladesh, changed considerably during the period 1600 to 2000 AD. It is difficult to trace accurately the various channels through which it flowed, but the probability is that it flowed past Rampur Boalia, through ChalanBeel, the Dhaleshwari and Buriganga rivers, past Dhaka into the Meghna estuary. In the 18th century, the lower course of the river flowed further south. About the middle of the 19th century the main volume of the channel flowed through this southern channel, which came to be known as Kirtinasa. Gradually the Padma adopted its present course.
Causes of Buriganga River Pollution
The City of Dhaka discharge about 4,500 tons of solid waste every day and most of it is released into the Buriganga.There are various causes of water pollution of Buriganga River.These causes are dividedbroadly in two divisions, namelya. Natural Causesb. Man-made Causes.
a. Natural causes: It is one of main causes of Buriganga river pollution.The biodegraded portions of plants and animals mix with water and pollute it. Erosion of river banks caused siltation and this silt sometimes hamper aquatic lives. Many kinds of natural salts and other substances mix with rain water and finally fall in the rivers and ponds.
b. Man-made causes: The major portion of water pollution of Buriganga river occurred by man-made causes. Industrial wastes, agricultural wastes, domestic wastes, excess use of fertilizer, pesticides etc. are notable man-made pollutants.
About more than 6,000 large, medium and small industries are operating in Dhaka.Among these industries, maximum industry discharge effluents directly to this river or nearby canal or waterbed without any regard to environment. 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 effluent treatment plants (ETPs) of their own. More than 60,000 cubic meters (2,100,000 cu ft) of toxic waste, including textile dying, printing, washing and pharmaceuticals, are released into the main water bodies of Dhaka every day.
According to the Dhaka Water and Sewerage Authority (WASA), about 12,000 cubic meters (420,000 cu ft) of untreated waste are released into the lake from Tejgaon, Badda and Mohakhali industrial areas every day. The waste mostly comes from garment washing and dyeing plants. Textile industries annually discharge as much as 56 million tons of waste and 0.5 million tons of sludge. Sewage is also released into the Buriganga. A newspaper article from 2004 indicated that up to 80% of Dhaka’s sewage was untreated.
One of the biggest pollutants of Buriganga is Hazaribaghtannery industry.Up to 40,000 tons of tannery waste flows into the river daily along with sewage. According to the Department of the Environment (DoE), 22,000 liters (5,800 US gal) of toxic waste are released into the river by the tanneries every day. About 12 sq. km area of Hazaribag and adjacent area are full of offensive odors of various toxic Chemicals: hydrogen Sulphide (H2S), ammonia, poisonous chlorine and several nitrogen based gases. According to an experiment, ”an average of 1 m3 water containing more than 300 different chemical compounds is being discharged daily from tannery industries.” The acidity, alkalinity and traces of chemical of this liquid waste change the pH level in water. Long term chromium contamination may cause cancer.
Agricultural Waste : These types of wastes are polluted the Buriganga indirectly. Because of Dhaka’s heavy reliance on river transport for goods, including food, the Buriganga receives especially high amounts of food waste since unusable or rotting portions of fruits, vegetables, and fish are thrown into the river.
Domestic Waste: The second biggest input of pollutant is Wastes form households which arise from the settlement of peoples along the river bank, using it as a disposal in their day to day activities. And the commercial waste is also one of the inputs of pollutants in to the river.According to World Bank study, about 0.5 million cubic meters domestic wastes(including medical, other solid wastes without industrial wastes) are released into the four major rivers near Dhaka- the Buriganga, Shitalakhya, Turag and Balu.
States of Water pollution of BurigangaRiver
A cruise on Bangladesh’s historic Burigqnga River used to be a must for visiting dignitaries, but now they are confronted with foul smell and rotting different wastes resulting from the massive pollution. Buriganga is connected with the Balu, the Dhalewswari, the Kaliganga and the Turag. Upstream of the Buriganga ends at 11km down from the MirpurBridge and downstream ends at Hariharpara. Total length of this river about 17 Km & average width about 0.6 Km. Its average depth is 7.6 meters(25ft) and its maximum depth is 18 meters(58ft). Average flow during wet season (May to Oct) is about 700 comic& during dry season (Nov to April) is about 140 comic.
Professor Abdullah Abu Sayeed, an eminent campaigner for “SaveBuriganga, Save Lives”said,“The World Bank study said four major rivers near Dhaka – the Buriganga, Shitalakhya, Turag and Balu — receive 1.5 million cubic meters of waste water every day from 7,000 industrial units in surrounding areas and another 0.5 million cubic meters from other sources. Unabated encroachment that prevents the free flow of water, dumping of medicinal waste and waste of river passengers have compounded the problem, making the water unusable for humans and livestock.“Unfortunately, all these bad things- encroachment, dumping of industrial waste and other abuses- occur in full knowledge of the authorities”.
In 1995, Bangladesh Govt. enacted a law making it compulsory for all industrial units to use effluent treatment plants in a bid to save river waters from pollution, but industry owners often flout the rule.“Many of them have this plant. But they don’t use it as it is expensive.” “We want the rivers fully dredged, their illegal occupation ended and the laws strictly enforced to prevent abuse of waterways, “Environmentalists say they are hopeful.“Not many days ago Singapore River was also like our Buriganga. But they cleaned it up and now turned it into a great resource,”
Among the top polluters are dozens of tanneries on the banks of the Buriganga. The government recently initiated a move to relocate the tanneries outside the capital, and also asked illegal encroachers to vacate the river.But environmental groups say they defy such orders by using their political links or by bribing people.The wastes of tanneries contain hexavallentchromium which is very harmful. The permeable concentration of chromium is 0.1 mg/L but it is found 2.6 to 28.0 mg/L in the water of Buriganga which is shown by the following Table,
Impacts of Buriganga
The people who are living by the BurigangaRiverwhich is polluted different types of wastes are suffering from various fatal diseases. Because, the main source of drinking water of people of Dhaka is Buriganga River. Some people bath here specially the habitant of slaves and evacuees of Dhaka.
The water of this river is now so polluted that all fish have died, and increasing filth and human waste have turned it like a black gel. Even rowing across the river is now difficult for it smells so badly.The pollutants have eaten up all oxygen in the Buriganga and we call it biologically dead. It is like a septic tank “There is no fish or aquatic life in this river apart from zero oxygen survival kind of organisms”.
About 12 sq. km area of Hazaribag and adjacent area are full of offensive odors of various toxic Chemicals: hydrogen Sulphide (H2S), ammonia, poisonous chlorine and several nitrogen based gases. According to an experiment, ”an average of 1 m3 water containing more than 300 different chemical compounds is being discharged daily from tannery industries.” The acidity, alkalinity and traces of chemical of this liquid waste change the pH level in water. Long term chromium contamination may cause cancer.
Exceeding limit of trace elements or ions may mix with water directly may be produced from the pollutants caused various harm for human and other living beings.
Toxic wastes or substances of Tannery and other industries directly affect living being through drinking water. Some toxic substances accumulate in the body and then express its contamination and create various diseases like Cholera, Diarrhea, and Dysentery etc.
Recommendation to Minimize theBurigangaPollution
Buriganga has enormous significance for the survival and economic growth of Dhaka City. Failure to protect Buriganga River from pollution means that a failure to policy makers who underestimating the benefits of environmental protection, restoration programs and economic growth. Public sector investment in developing countries such as Bangladesh needs redirection to respond to emerging environmental problems such as water and air pollution and global warming. It argues a better environmental protection and an improved river management can be achieved which overall will provide for a more sustainable development.
Early implementation of efficient management practices will save the Buriganga River. It has been seen that this river has considerable pollution assimilation capacity which provides considerable opportunity for improving water quality. For this some steps are necessary. Some of them are:
n Industries should be located in separate area and act of establishing industries must follow properly. And effluent of industries must be treated and monitored sincerely before throwing it to water body.
n The government of Bangladesh recently initiated a move to relocate the tanneries outside the capital and also asked illegal encroachers to vacate the Buriganga River.These steps should be effective within short time.
n A huge quantity of polythene is used in Bangladesh which is a non-degradable pollution is dumped into this river should be removed.
n Sir Salimullah Medical College & Hospital authority to stop dumping of hospital waste into this river.
n The people who built illegal structure on the river banks would have to pay demolition charge.
n Bangladesh government enacted a law in 1995 making it compulsory for all industrial units to use effluent treatment plants in a bid to save river waters from pollution, but industry owners often flout the rule. They defy such orders by using their political links or by bribing people. Govt. should take necessary steps against the illegal owners and law Breakers.
The writer is student of Economics at Jagannath University, Dhaka.