All activities that seek to minimise the health, environmental and aesthetic impacts of solid wastes are included in solid waste management. Generally the term solid waste includes human or animal excreta and such materials. But material which is not in liquid form, and has no value to the person who is responsible for it is actually solid waste. “Garbage”, “trash”, “refuse” and “rubbish are the terms which are the synonyms of solid waste. Solid wastes from houses, streets and public places, shops, offices, and hospitals, which are very often the responsibility of municipal or other governmental authorities is referred to as municipal solid waste. Solid waste from industrial processes cannot be considered "municipal" waste. But they need to be dealt with solid waste stream as they often end up in the municipal solid waste stream.
Waste is created through human activities. The way in which these wastes are handled, stored, collected and disposed of can pose risks to the environment and to public health. Problems and issues of Municipal Solid Waste Management (MSWM) are of immediate importance in urban areas, especially in the rapid urbanizing cities of the developing world. Most governments have acknowledged it. However rapidly the population growth over-whelms, the capacity of most municipal authorities is restructured to provide even the most basic services. Typically much part of the solid waste generated is not collected. Thus the uncollected waste gets mixed with human and animal excreta, which is then dumped indiscriminately in the streets and in drains, so contributing to flooding, breeding of insect and rodent vectors and the spread of diseases. Even the collected waste is often disposed of in uncontrolled dumpsites or burnt, polluting water resources and air.
Though urbanisation in developing countries has contributed to wealth accumulation, it has also been accompanied by an alarming growth in the incidence of poverty. Today many people in cities lives in absolute poverty and some in relative poverty. Life threatening conditions deriving from deficient MSWM is mostly suffered by the urban poor who live in peri-urban areas. Municipal authorities allocate their limited financial resources to the richer areas of higher tax yields where citizens with more political pressure reside. Usually as income of the residents' in-creases, part of the wealth is used to avoid exposure to the environmental problems close to home, but as waste generation also increases with increasing wealth, the problems are simply shifted to some other places. The preparation and management of a high-quality solid waste management system needs contributions from a range of disciplines, and cautious concern of local conditions.
Challenges faced by Solid waste management
There are a number of problems faced by the Municipal Solid Waste Management (MSWM) of developing countries. Some of them are described below.
Service coverage
Generally only a limited part of the urban population is served by the Municipal solid waste collection schemes of cities in the developing world. Waste collection services are not usually available for the low-income population. Inefficient institutional structures, inefficient organizational procedures, or deficient management capacity of the institutions involved can also be the reason that affects the availability or sustainability of a waste collection service.
In many countries there is presently great interest in linking private companies in solid waste management. Sometimes this is driven by the failures of municipal systems to supply adequate services, and sometimes by pressure from national governments and international agencies. Arrangements with private companies have not all been successful, and as a result some opposition to private sector participation is now in evidence. A recurring problem with collection schemes that operate at the community level is that these systems generally collect and transport the waste a relatively short distance up to a transfer point, from where the waste should be collected by another organisation often a municipality. Problems of coordination and payment often result in the waste being left at transfer points for a long time creating a hygienic unsatisfactory situation. Another move towards waste management is to recycle as much of the waste locally so that there is very little need for on going transport of collected waste.
Resource recovery and recycling
Recycling inorganic materials from municipal solid waste is often well developed by the activities of the informal sector. But such activities are rarely accepted, supported, or promoted by the municipal authorities. The cost of the separated material, its purity, its quantity and its location are some factors that the potential for resource recovery. The economic potential for resource recovery is decided by the major factors like costs of storage and transport.
Reuse of organic waste material that contributes to more than 50% of the total waste amount is still quite limited but often has enormous recovery potential. It reduces costs of the disposal services, prolongs the sites life span, and also reduces the environmental impact of disposal sites as the organics are largely to blame for the polluting leachate and methane problems. This is one of the reasons why solid waste managers in many parts of the world are now exploring ways to reduce the flow of biodegradable materials to landfills. For the success of composting activities to manage organic waste is, a clear legislation, policy and municipal strategy.
DisposalMost of the municipal solid waste (MSW) in developing countries is dumped on land in an uncontrolled manner. These dumps make very uneconomical use of the available space, allowing free access to waste pickers, animals and flies and often produce unpleasant and hazardous smoke from slow-burning fires. Financial and institutional restrictions are the main reasons for insufficient disposal of waste particularly where local governments are weak or underfinanced and rapid population growth continues.
Financing of safe disposal of solid waste poses a difficult problem. This is because most people are willing to pay for the removal of the refuse from their immediate environment. But no one is generally concerned with its ultimate disposal. The present disposal situation is expected to deteriorate even more as with rapid urbanization settlements and housing estates now increasingly encircle the existing dumps and the environmental degradation associated with these dumps directly affect the population. Waste disposal sites are therefore also subjected to growing opposition and it is becoming increasingly difficult to find new sites which find public approval and which are located at a reasonable distance from the collection area. Finding landfills at greater distances to the central collection areas implies higher transfer costs as well as additional investments in the infrastructure of roads hence intensifying the financial problems of the responsible authorities. In addition to all this, an increase in service coverage will even aggravate the disposal problem if the amount of waste cannot be reduced by waste recovery.
Other reasons for inadequate disposal are the mostly inappropriate guidelines for finding sites for landfills, design and operation of new landfills. Many of the municipal officials think that uncontrolled waste disposal is the best that is possible. Often the only guidelines for landfills available are those from high-income countries. These are based on technological standards and practices suited to the conditions and regulations of high-income countries and do not take into account for the different technical, economical, social and institutional aspects of developing countries.
There are many factors that influence the Solid Waste Management and vary from place to place. Typically, domestic waste from industrialised countries has a high content of packaging made of paper, plastic, glass and metal, and so the waste has a low density. In many developing countries wastes contain large amounts of inert such as sand, ash, dust and stones and high moisture levels because of the high usage of fresh fruit and vegetables. These factors make the waste very dense.
Public awareness and attitudes to waste can affect the whole solid waste management sys-tem. All steps in solid waste management starting from household waste storage, to waste segregation, recycling, collection frequency, the amount of littering, the willingness to pay for waste management services, the opposition to the siting of waste treatment and disposal facilities, all depend on public awareness and participation. Thus this is also a crucial issue which determines the success or failure of a solid waste management system.
