Study on solid waste management system of Dhaka Metropolitan City

Abstract

Municipal solid waste management is a growing environmental and financial problem in developing countries. Despite significant efforts in the last decades, the majority of municipalities in developing countries face difficulties in managing the growing quantity of waste in their cities. Dhaka, the Capital City of Bangladesh, is one of the fastest growing metropolises of the world with an annual average growth rate of 6.6 %. Due to high density of population (about 200 persons per acre) and continued inward migration of more people, managing solid waste has become a challenging task. The study revealed that, Dhaka City Corporation (DCC), responsible for management of solid waste of Dhaka, is inefficient and unsatisfactory. The total amount of municipal solid waste generated every day is about 3,000 tons from 5.38 million residents. Inspite of uncontrolled recycling, mostly by scavengers, DCC can handle only 42% of the generated solid wastes. With limited resources in terms of money, skilled manpower and logistics, managing such bulk volume of solid waste is difficult for DCC. Only 30% of the population use roadside bins and the rest throwaway their waste on the drains, low-lying areas, streets and open spaces. 9% of the slums in DCC area have any form of solid waste collection service and as a result the remaining 91% slums dump their waste on open land, roadside and khals. Transportation of solid waste through open truck (43%) results public nuisances due to irregular cleaning of open bin and removal of demountable containers. All these wastes, uncollected and untreated in open spaces, are left to rot, which pose a threat to the public health, environment as well as the ecology. It is observed that, faced with such unsatisfactory and inadequate management system of DCC community people are now coming forward to deal with the solid waste problem themselves. About 130 Community Based Voluntary Organizations have started working in Dhaka City, providing door-to-door waste collection services and disposing off their collected waste into the nearest DCC communal solid waste collection bins/drop boxes (containers). This study gives two examples - one is an NGO (Waste Concern) and the other is a CBO (RECP), which is acting independently, without any kind of involvement or help from DCC. They are managing their waste themselves from collection to disposal. The study shows that they are very successful with highly satisfied clients and have created significant employment. It is found from this study that domestic waste generation rate from medium-income residential area (0.32-0.37 kg/capita/day) is higher than that from slum area (0.23- 0.25 kg/capita/day). A graphical representation of variation of waste generation rate with respect to income generation demonstrates that the waste generation rate vary with respect to income level of people and the type of area. It is apparent from the physical composition of waste that major portion (80-90% )of domestic solid waste in Dhaka City is organic. Presence of high organic matter in the waste suggests that composting could be a viable option of waste disposal as there is good market .for compost, for majority of the land use in greater Dhaka and adjoining areas is agricultural. Composting can either be done by constructing a composting plant or by placing composting barrels in backyards of households. Financial feasibility analysis for a 3- ton capacity composting plant and alternatively for using 200-liter composting barrels (where land is constraint), for Study Area-I at Rayer Bazar (ward no. 47) shows that the return on investment (considering 5 year project) is viable. The study reveals that integration of primary collection and composting is necessary for projects to be socially and commercially viable and sustainable. All what can be conclusively said is that, decrease in the amount of solid waste to be disposed off in landfill site through resource recovery and recycling, could be the right solution, since municipal solid waste is composed of high organic matter, which can be converted into compost by less capital intensive community-based composting plants. However, the application of these technologies requires further detail study and long-term experimental verification for other wider application and commercial use in Bangladesh.