Tariq Bin Yousuf
SOLID WASTE AND ITS MANAGEMENT are the key areas of environment and health concern that the cities are currently facing. The rapidly swelling population, increasing urbanisation and intensifying economic activities have all contributed to generation of wastes. Municipalities are increasingly overburdened and unable to cope with the ever-increasing magnitude of urban wastes. Waste management costs are escalating and this trend is putting more and more pressure on municipalities' budgets. Waste is an unwanted and useless by-product of our daily consumption, affluence and comfort. We produce waste daily but we are not aware of managing it properly, put burden on the nature's assimilating capacity. The industries are polluting the water bodies through untreated discharge; the liquid wastes are discharging directly into the river; solid waste finds its way into the city streets and low lands. The picture is very disappointing and dismal. When waste is disposed in land, it causes land pollution; when burnt, causes air pollution; and when dumped in landfills, causes surface and groundwater pollution. In addition, it has aesthetic and health implication. The municipalities spend 20-40 per cent of their municipal revenues, employing 1-2 workers per 1000 person on solid waste management. The present practice of waste handling and transportation permits only about half of the wastes to be collected and disposed. The rest are left on the streets or find the way into drains or low-lying areas, causing pollution of water resources, water logging and proliferation of flies, mosquitoes and rats.
As the cities are expanding and population increases, the existing capacity and trend of waste management does not perform the desired level of service. The existing service of waste management is primitive in nature and follows the collection-transportation-disposal hierarchy. The present system of waste management has drawn much criticism. The city streets are littered with garbage; the communal bins are spilled over by the wastes creating a messy scenario. Dumpsites in the city are more and more difficult to obtain and trucking of wastes out of the city is more and more expensive. Local community-based waste collection schemes are a shining light but the secondary collection points are again gloomy. The disposal sites are havoc, uncontrolled dumping threads to surface and groundwater pollution.
Proper handling and managing of waste has value if we follow the 4 R principles reduce, reuse, recovery and recycling. Large numbers of people are supported by waste picking and recycling activities, which may be unsanitary but important in terms of economics and reducing the quantities of waste requiring disposal. The waste recycling activities are still the businesses of the informal sector but if the government supports the businesses they will be gold mines as predicted by the UNEP executive director.
Public participation is a vital tool for managing the waste in an efficient way. By sorting out household garbage in a proper way and offering waste at the right place at the right time for collection contributes to local level of waste management. Avoiding indiscriminate littering of garbage contributes to community level and avoid burning of wastes is a small act but a big contribution to the global arena of waste management.
The community-based waste collection is active in the neighbourhood. The interface of the community collection and the secondary storage points are critical. Wastes are found scattered around the communal bins, occupying significant parts of the roads. Neither the public sector nor the community effort can alone achieve the improvement; co-management is the way to go on the basis of sharing the responsibilities.
Public health and environmental consequences of waste
Solid waste management is directly related to residents' health and hygiene as well as overall environment of the city. Inadequate and improper solid waste management causes spillage of wastes around the bins, discharges obnoxious odour, creates nuisance and hazards in the surrounding area. The disposal grounds are the breeding places of vectors, insects and rats, which transmit deadly diseases like plague, dengue etc. Indiscriminate dumping of wastes and polythene causes clogging of drainage and sewerage systems. Dumping of untreated solid and hazardous wastes from industries destroy the flora and fauna and the ecosystem of the adjoining areas, contaminating surface and groundwater. The present land filling practice is an environmental disaster, causing health risks from different vectors and contributes to air, surface and groundwater pollution from leachate and landfill gases. Uncontrolled disposal of hospital wastes containing pathogenic bacteria spread harmful diseases like Hepatitis B, AIDS, etc.
Constraints in waste management system
Waste management is a complex task. It has multidimensional focus to attend - social, environmental, financial and technical. Limited finances and inadequate services handicap the municipalities for delivering the desired service to the city dwellers. Low level of institutional capacity and financial management, transparency and accountability of the system, public attitude and awareness, strong political will and commitment all contribute to the inefficiency and inability of the waste management system. The attention and improvement of the identified problems by the municipalities can resolve the waste crisis to a satisfied level.
Waste management hierarchy and sustainable way of management
Traditionally, people rely solely on municipalities to deliver services to solve the solid waste problem. Municipalities also do it on its own tax-based resources, using top-down approach with hardly any consultation with the people. The waste management hierarchies and stages are the key solution for a better management. Waste avoidance, minimisation, separation and recycling are ranked as the most preferred and dumping, open burning are least preferred options of a good hierarchy. The desirable steps optimise the conservation of natural resources, create employment and income, reduce the burden of waste collection and disposal, extension of service life of landfills.
The sustainable waste management system can be defined by the system which removes wastes economically with low investment costs, is socially and politically acceptable and finances its own operation. The principles of sustainable waste management are to minimise waste generation; maximise waste recycling and reuse; make efficient and economic waste transportation; and ensure safe and environmentally sound disposal of waste. The community has a great role to play in solving waste-related problems and contributes to sustainability. The communities themselves identify the need and the problem, and share their experiences to solve the problem. Effectiveness and sustainability of waste management system depends on the public attitude and practice towards waste handling and takes ownership of the system. In the Agenda 21 of the UNCED 1992 conference, a global consensus has been emerged that implementation of sustainable development should be based on local-level solutions and community participation. The success and sustainability of a programme affirms participation by consensus and ownership building through the process of consultation, collaboration and co-ordination assessing its reliability, affordability and replicability.
Policy regulation and development strategy
The policy and strategy should be designed as best suit to society, economy and environment with a long term vision, dedication, commitment and strong political determination. The policy needs to be well supported by regulation and enforcement. The Environmental Policy'92, Municipal Ordinance, Bangladesh Environmental Conservation Act'95 and Rules'97, National Policy for Safe Water Supply & Sanitation '98 all are supporting guidelines and legal framework for a good waste management system in Bangladesh.
The development strategy of the government (Fifth Five Year Plan) ensures environmental protection and promotion of sustainable environmental management through participatory and community based environmental resource management and prioritises environmentally sound and sustainable technology. The Government response towards the environmental issues and concerns is positive and its development strategy is proactive towards the environmental protection. The mass awareness of environmental ethics such as public education and knowledge about the rules and regulations and then stricter monitoring and enforcement can contribute to the behavioural changes of the people. If everyone practices the ethics in his personal life, that may lead to change in the society.
Solid waste management activities
Street sweeping, drain cleaning, waste collection, transportation and disposal are mandatory functions of the municipality. Now the municipality does the functions involving his workforce, vehicles and other logistics in an inappropriate and unhygienic way that indirectly offsets the city's image and economy. The way of waste storage, handling, transportation and final disposal are much criticised by people, as the present practice is detrimental to their health and wellbeing. The street sweeping is virtually confined in the main roads, does not bring any impact in the locality. Occasionally, the surface drains are cleaned but the heaps of silts are left to dry for a period of time. The wastes from the household are carried by wheelbarrows or vans and dumped near the containers where scattered garbage blocking the significant portion of the roads.
A fleet of open, closed and de-mountable container carrying trucks is engaged for waste transportation. The way the open truck is working is disappointing as it stands still for 75 per cent of the time for loading, blowing of garbage, and discharging bad odour on the way of transportation. The covered truck with roller shutter is a sanitary way of transportation but the loading and unloading mechanism of waste for a man to stand straight inside is inhuman and unhygienic. The de-mountable container system is suitable and efficient for mechanisation of waste handling and transportation. The system needs manoeuvring space at the pick-up point to place one container on the ground before picking up the full one. The main intention of introducing de-mountable container system was to containerise the waste with a view of reducing the number of manual handling. But in practice, it is seen that waste is spilling outside the container, requires manual loading and accounts for costly, as the main concept of handling of containers cannot be applied due to limited space on the roadside.
Municipal solid wastes are dumped in low-lying marshy areas, which is unsafe, unhealthy and environmentally unsound. Risk of contamination of water resources, potential health risks to local communities and high risk of collapse and explosion may occur if the landfill sites are operated in a crude manner. The experimental results of the Environmental Engineering Department of the BUET on some of the former and present landfill sites show alarming indication of ground and surface water pollution along with traces of heavy metal concentration.
Good practices in waste management
In addition to the traditional practices of waste management in Dhaka and some other cities, some good practices are taking place, which compliment and supplement the efforts of the municipal authorities.
Opportunities for improvement
It is encouraging to say that lot of initiatives and efforts towards clean environment are taking place. If the initiatives are tapped into the mainstream of the city waste management and good collaborative support are given to the private enterprises, then the waste scenario of the cities might be changed. Several options can be piloted for judging the best one to be replicated. Many community initiatives are working, the urgent need is to prepare a database to make their activities well integrated and accounted with the municipal secondary collection. The commonly followed rickshaw vans for carrying wastes need to be modified with the provision of placing several small containers in the platform which can be emptied directly into the secondary container. This perhaps will improve the scenario of scattered garbage around the container.
If places are available, mini transfer station can be set up, where the containers can be loaded from a raised platform and at the same time recycling plant can be established which will help to reduce the wastes to be transported.
Area-wise integrated programme - street sweeping, drain cleaning, waste collection and transportation - can be privatised to a company and analyse the suitability, performance and cost-effectiveness on a trial basis.
Municipalities have to strengthen the institutional capacity and financial management. The de-mountable container system is apparently good but costly due to misleading with the actual concept. The strong monitoring and incentive mechanism along with the possibility of installation of weigh-bridge at the dumpsite can make the system efficient.
The crude way of waste disposal should be avoided as surface and groundwater is being polluted. The best option is the controlled management of dumpsite with compacted clay liner for the protection of ground intrusion and re-circulation back of the leachate to the landfill allowing faster decomposition and reduction. Landfill gas can be controlled by installing vent pipes for releasing gas to the atmosphere or contracting out to any private company for generation of energy.
Finally, it can be recommended that individual level capacity and awareness towards cleanliness should be grown first. Then promotion of appropriate technology and replication of good practices, establishment of legislative and enforcement mechanism, development of linkage and partnership program should be adopted and implemented for a better waste management system. If we can change our habit and manage our waste properly we can keep a healthy and liveable environment for our next generation.
Tariq Bin Yousuf, an engineer, works for the Dhaka City Corporation.
Source : The Daily Star, Dhaka, July 20, 2001