Time to save the Turag from pollution
A plastic industry on the Turag bank at Dhaur: Potential source of disposing toxic liquid chemical waste directly into the river.
River pollution has been one of the main talked about topics in the environmental issue of urban Dhaka. Since the birth of Bangladesh due to rapid and unplanned urbanization and industrialization the rivers surrounding the capital city, including the Turag have been steadily experiencing complicated problems like pollution and encroachment that have almost suffocated these valuable lifelines of the city. The writer has roughly appraised the pollution of the Turag River especially from the Buriganga Third Bridge to the Tongi Bridge and found two points with extreme pollution. This write-up discusses these two pollution points of the river homing in on the sources and causes of pollution, its impacts on the surrounding environment and possible sustainable remedies. Pollution points and impactsThe highest pollution points of the Turag River include the Buriganga Third Bridge area at Bashila and the Tongi Bridge area. At these two points, the river water is pitch-black with the worst of smell and can be used for hardly any purpose as at both points DO (Dissolved Oxygen) level is 0, almost all the year round except during the rainy season when the river becomes full to the brim; whereas DO level necessitates 6 mg/l for drinking, 4-5 mg/l for recreation, 4-6 for fish and livestock, 5 for industry and irrigation according to the Environmental Quality Standard (EQS) complied in Bangladesh. The tolerable level of Biological Oxygen Demand (BOD) is 0.2 mg per liter for drinking, 3 mg/l for recreation, 6 mg/l for fish and 10 for irrigation. But the present BOD level at these two points is absolutely ignorable for any use. Similarly, other parameters of water quality like TDS, TSS, TS, Turbidity, Conductivity, COD, pH, Cadmium, Copper, Zinc, and Lead are gradually obtaining such figures that have already surpassed the tolerability. Due to over spilling of pollutants during the rainy season, the agricultural lands of Washpur and Shalmasi of Keraniganj and Bashila and Katasur of Mohammadpur have been so contaminated that they have lost their crop growing capacity and hence remain unused all the year round. Of course, some of the lands are now experiencing other uses like housing project and brickfield development. These land uses eventually cause illegal occupation of river banks and increase pollution concentration in the river. Sometimes the pollutants enter food chain eventually killing birds, fish, and mammals. Pollution concentration here increases abruptly at the advent of the lean period as the water level of the river recedes a lot at this time but the rate of pollutant released into the river remains identical. At this period, pollution is so acute that hardly any hydro-organisms can tolerate it and eventually, fish of many species are found floating dead in the river water. These dead fishes gradually get rotten and highly add to the further pollution of the river water. Sources and causes of pollution
The pollution spot near the Buriganga Third Bridge experiences huge toxic chemical liquid waste from the Hazaribagh Tannery area through Bashila Khal. There are about 149 tanneries in Hazaribagh which daily generate about 18,000 liters liquid and about 115 metric tones solid waste almost all of which get released into the river Turag through Bashila and Katasur khals. Examples of such pollutants include cyanide, zinc, lead, copper, cadmium, and mercury. There are many slum type houses on both sides of Rayer Bazar Embankment and also on the Katasur Khal. The slum dwellers use unhygienic open latrines. All the domestic and human waste they generate gets discharged in the Turag River through khals. All these contribute to the pollution of a portion of the Turag River close to the Buriganga Third Bridge. The pollutants diffuse up to the Iztema field area at Tongi Pourosova from this downstream point of the Turag. The other extreme pollution spot is near the Tongi Bridge that derives massive pollutant loading from the Tongi Industrial Area. This industrial area possesses about 29 heavy industries. This cluster of industries of the capital city generates 7,159 kg effluents daily (IWM, 2008). A study was conducted by H. M. Zakir, Sharmin Shila and Shikazono Naotatsu in 2006 to investigate the heavy metal contamination of water and sediments of Turag River at Tongi area. Untreated urban sewerage and industrial wastewater from Tongi area affect water chemistry of this part of the Turag River. Fourteen samples of water and sediments were collected from both sides of the river. The results showed heavy metal concentrations in the water greatly exceeding the standard values for the surface water quality. The mean concentrations of Mn, Zn, Cr, Cu and Pb in the sediment samples (896, 111, 97, 49 and 24 ìg g?1, respectively) were higher than the standard. The enhanced metal concentrations are related to the direct discharge of the industrial and municipal wastes into the river. Major limitations and suggested remedial actions
To ensure rapid development of the nation, obviously there is no alternative to massive industrialization. But ironically the scenario in Bangladesh is that we always try to ignore and bypass the issue of sustainably managing the waste that the industries generate essentially in the production process. The present ETPs (Effluent Treatment Plants) status in Bangladesh makes the situation blatantly obvious to us. According to an industrial survey conducted by Bangladesh Center for Advanced Studies (BCAS) in 2009, only about 40% industries have ETPs. In 10% industries, ETPs are under construction and about 50% industries have no ETP establishment. That is, more than 50% of waste generated by the industries eventually goes to the rivers untreated. At this state things, there is no time like the present for the government to put pressure on the industry-owners to establish ETP on their respective industry premises. Moreover, the government also should scrutinize whether the ETPs are operated properly or not because all the industries having ETPs don't keep them operational all the time. At times it may be beyond the economic strength of many industries to brace the establishment and operation cost of an ETP single-handedly. In these cases, the government can provide technical help and subsidy to those industries. In addition, a cluster of industries can jointly bear the expenses and treat their generated waste establishing a common ETP. It is a ray of hope that recently the industry owners of Tongi Industrial Area have unanimously decided for establishing and operating a central ETP with their concerted effort with a view to tackling the Turag River pollution (Prothom-Alo, August 31, 2010). This welcoming manoeuvre the government should seriously adjudge and exploit the conscious feelings of the industry owners for other areas. If this system fails for some reason, the government may think to introduce Polluters Pay Principle (PPP). The government can establish and run ETP at the premises of each industry levying its expenses on the respective industry authority. It is praiseworthy that the monitoring and enforcement wing of the Department of Environment has been launching anti-pollution drive. The anti-pollution drive body has fined eight industries polluting the Turag River and directed them to establish and run ETP. The government has already taken a decision to shift the tannery industry from Hazaribagh to Savar. But only shifting will not sustainably solve the pollution problem caused by the tannery industry. Rather sufficient number of ETPs and other waste treating devices must be ensured at the new site. Concluding remarks
If the sources of these two major waste disposal outlets into the Turag River can be taken care of, it is firmly expected that the river can get relieve from pollution to a great extent and now is the time for sealing these waste dumping outlets as the pollution level of the Turag has not yet gone beyond treatability like that of the Buriganga and the Shitalakhya. So, the government and other stakeholders should seriously consider taking effective actions before it is late.
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