World Student Community for Sustainable Development

by Faisal Ibney Hai, Department of Urban Engineering, University of Tokyo, Tokyo, Japan

Until recently, the environment was not an issue in a developing country like Bangladesh, and solid waste management was definitely not the prime concern of environmentalists and the government when the awakening to the issue finally did occur. It has only been in very recent times, when certain NGOs started working and highlighting the pathetic state of municipal waste services provision in the country, that the decision-makers realized the importance of this particular aspect of environmental management. [1] This short communication is intended to encapsulate an evaluation of the existing solid waste management system of Dhaka City Corporation and an assessment of the impacts associated with the current practice of final disposal of solid waste, with a special focus on the effect of composting on land requirements and landfill gas generation, and the effect of landfill location on transportation costs.

Solid waste disposal poses a greater problem because it leads to land pollution if openly dumped, water pollution if dumped in low lands, and air pollution if burnt. Dhaka, the capital city of Bangladesh and home to an estimated 10 million people, is facing serious environmental degradation and public-health risk due to uncollected disposal of waste on streets and other public areas, drainage congestion by indiscriminately dumped wastes, and contamination of water resources near uncontrolled dumping sites. Dhaka City Corporation (DCC), the responsible authority for solid waste management in the city, is falling short in providing a satisfactory service to the city dwellers with its limited resources and a poor management plan. An inadequate information base on the quantity, type, and characteristics of wastes; poor operation and maintenance of service facilities; and, above all, a lack of civic awareness on the part of a section of the population are together leading to the deteriorating environmental situation.

A DCC estimate [2] shows that, of the total daily generation of 3500 tons of solid waste, 1800 tons are collected and dumped by the DCC, 900 tons end up in backyards and informal landfills, 400 tons end up on roadsides or open space, 300 tons are recycled by the Tokais (destitute slum children acting as scavengers), and 100 tons go through informal recycling at the point of generation. Household, commercial, and industrial wastes are deposited in collection bins on the streets. DCC vehicles, which vary in size, age, and design, collect the waste from the bins and transport it to dumping sites. The ill-planned distribution of DCC vehicles results in poor collection efficiency while imposing considerable cost. In fact, fuel costs account for about 18 percent of DCCâ€^TMs total expenditures. [3] The collected waste is disposed with a crude, open-dumping method, which triggers further environmental hazards and health risks.

According to DCC, six dumping sites have already been abandoned after filling to their capacities. [4] It is estimated that existing sites will fill up shortly and DCC will have to arrange for new dumping sites for waste disposal. Dumping of wastes at sites increasingly far from the city center without any provision for transfer stations could become a major financial burden for the DCC in the coming years. Indeed, it has been estimated that the imminent selection of dumping sites far from the city center due to unavailability of land and/or higher land price would triple the present daily waste transportation costs. [5] Furthermore, projections of future waste generation rates indicate that by the year 2020, DCC may face 30,000 tons of waste per day (nearly 9 times the amount currently generated), which will require 206 acres of landfill per year.

In this context it is interesting to note that the mixed waste dumped at DCC dumping sites is high in organic content (about 80 percent by weight) and high in moisture content (50 to 70 percent by weight), however with low calorific value (1386-2600 Btu/lb). [6] Therefore, to minimize the increasing land area used for disposal of solid waste, an effective option would be to reduce the volume of solid waste prior to disposal by composting organic wastes and recycling inorganic wastes. Experts have suggested that composting projects can be made financially and technically viable if they are decentralized, located close to the source of waste generation, and — most importantly — low-cost manual technologies, taking into consideration the local socio-economic conditions, are adopted. [7]

If organic waste is composted, analyses show that land requirements drop dramatically. In 2020, the composting of 40 percent of organic waste would require 167 acres per year and the compost of 80 percent of organic waste would require just 97 acres per year — compared to 206 acres per year without any composting. Furthermore, with composting, the peak rate of generation of the greenhouse gas methane would be as low as half of that for no composting. [8]

It should be emphasized that a community-based solid waste management system involving recycling and composting, in conjunction with sanitary land-filling, and possibly provision for transfer stations if the landfill is far away, may be the way out of the current inefficient system. If the undesirable adverse impacts from overflowing waste bins and accumulated wastes on roadsides are to be avoided, strict rules will need to be applied and enforced, and public awareness must be increased.

Footnotes

[1] Sarmin, T. 2000. “Study of Present Status of Solid Waste Management Practices of Dhaka City†, B.Sc. Engineering Thesis in Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka, June.

[2] Dhaka City Corporation. 1999. “Solid Waste Management by Dhaka City Corporation†[booklet collected through personal communication].

[3] Kazi, M.N. 1999. “Capacity Building for Primary Collection in Solid Waste.†Citizens Guide for Dhaka, Environmental and Development Associates (EDA), Dhaka, Bangladesh, in association with Water, Engineering and Development Centers (WEDC), Loughborough University, UK.

[4] Dhaka City Corporation. 1999. “Solid Waste Management by Dhaka City Corporation†[booklet collected through personal communication].

[5] Hai, F.I., and M.A. Ali. 2004. “A Study on Solid Waste Management System of Dhaka City Corporation: Effect of Composting and Landfill Location.†Technical Journal of the Department of Civil and Environmental Engineering of the University of Asia Pacific, Bangladesh, April.

[6] IFRD. 1998. “Refuse Quality Assessment of Dhaka City Corporation for Waste to Electrical Energy Project†[project funded by the World Bank and Power Cell, Ministry of Energy and Mineral Resources, Government of the Peopleâ€^TMs Republic of Bangladesh, performed by the BCSIR, Dhaka, July.

[7] Enayetullah, I., and A.H.M.M. Sinha. 2002. “Decentralized Composting: Experience of Waste Concern in Dhaka, Bangladesh.†Training Workshop on Incorporation of the Informal Sector Waste Pickers and Community-Based Decentralized Composting in Formal Solid Waste Management System, United Nations Economic and Social Commission for Asia and the Pacific, Dhaka, December.

[8] Hai, F.I., and M.A. Ali. 2004. “A Study on Solid Waste Management System of Dhaka City Corporation: Effect of Composting and Landfill Location.†Technical Journal of the Department of Civil and Environmental Engineering of the University of Asia Pacific, Bangladesh, April.