Solid waste is any material which comes from domestic, industrial and commercial sources arising from human activities which have no value to people who possess it and is discarded as useless. Before, waste disposal did not pose difficulty as habitations were sparse and there was plenty of land. It became problematic with the rise of towns and cities where large numbers of people started to congregate in relatively small areas in pursuit of livelihoods (Shafiul and Mansoor, 2003). While the population densities in urbanized areas and per capita waste generation increased, the available land for waste disposal decreased proportionately. Through this solid waste management emerged as an essential, specialized sector for keeping cities healthy.
Solid waste management refers to source separation, storage, collection, transportation and disposal of waste in an environmentally sustainable manner. According to World Bank (2007), the overall goal of solid waste management is to treat and dispose of solid wastes generated by all urban population groups in an environmentally and socially satisfying manner, using the most economical means available. According to Zerbock (2003) developing countries spend about 20-40 percent of their revenues on waste management but are still an unable to keep pace with the scope of the problem. When the governments of African countries were required by the World Health Organisation (WHO) to prioritize their environmental health concerns, the result revealed that solid waste was identified as the second most important problem after water quality (Senkoro, 2003 cited by Zerbock, 2003).
The United Nation estimates that the world will be 51.3% urban by 2010, meaning the majority of people will be in the cities. Consequently, due to the rapid rate of urbanization a growing strain has been placed on urban governments, which lack capacity, infrastructure and resources to cope with existing population and migrants. One key result is that uncollected waste, which is often mixed with human and animal excreta, and hazardous and medical waste is burned or left dumped in streets and open fields, contributing to serious environmental contamination that gravely affects the health of communities (Markel et al, 2000).
Poorest neighbours in the urban area suffer life-threatening consequences derived from neglected solid waste disposal. When pressed; local governments tend to limit their financial resources to richer areas that hold more political clout. Thus, direct exposure to environmental contamination and its effects are often left the urban and peri-urban populations living in low income neighbourhoods. Consequently, without clear global and local strategies for solid waste management, rapid urbanization will continue to exacerbate environmental health and socio-economic problems (Ferrara, 2007).
Solid waste management is one of the most challenging issues in urban cities, which are facing a serious pollution problem due to the generation of huge quantities of solid waste (Sunil Kumar et al, 2008). Solid waste is considered any material that arises from human and animal activities that are discarded as useless or unwanted (Tchobanoglous et al., 1993). It does not mean that the solid waste have no value; it simply means that it has no value to the current owner. If the solid wastes have value for a new owner, these materials are no longer solid wastes but rather raw materials for further use with renewed value until the new owner decides to discard them as solid waste (EPA, 2002).
Types and components of solid waste
Table: Typical waste generation facilities, activities, and locations associated with various sources of solid waste
|Source||Type location||Types of Solid Waste|
|Residential||Single-family and multifamily dwellings, low-medium, and high-rise management||Food wastes, rubbish, ashes, special waste|
|Stores, restaurants, markets, office buildings, hotels, motels, print shops, auto repair shops, medical facilities and institutions.||Food wastes, rubbish, ashes, demolition and construction wastes, special wastes, occasionally hazardous wastes.|
|Industrial||Construction, fabrication, light and heavy manufacturing, refineries, chemical plants ,lumbering, mining demolition||Food wastes, rubbish, ashes, demolition and construction wastes, special wastes, occasionally hazardous waste.|
|Open areas||Streets, alleys, parks, vacant plots, playgrounds, beaches, highway and recreational areas.||Special wastes, rubbish|
|Treatment plant sites||Water, waste water, and industrial treatment processes||Treatment plant wastes, principally composed of residual sludge.|
|Agricultural||Field and row crops, orchards, vineyards, dairies, feedlots and farms.||Spoiled food wastes, agricultural wastes, rubbish, hazardous wastes|
Source: Tchobanoglouset al 1993 p.52-53
Tchobanoglouset al (1993), classified types of solid waste in relation to the sources and generation facilities, activities, or locations associated with each type which is presented in the table above.
Tchobanoglouset al (1993) has further explained the types of solid waste which include food waste, rubbish, ashes and residues and special waste. These are explained below:
Food waste: Food wastes are all the animal, plant or vegetable residues resulting from handling, preparation, cooking and eating of foods (also called garbage).The most important characteristics of these wastes is that they are highly putrescible and will decompose rapidly, especially in warm weather. Often decomposition will lead to the development of offensive odours. In many locations, the putrescible nature of these wastes will significantly influence the design and operation of solid waste collection.
Rubbish: Consists of combustible and non-combustible solid wastes of households, institutions and commercial activities. This excludes food wastes or other highly putrescible materials. Typically, combustible rubbish consists of materials such as paper, cardboard, plastics, textiles, rubber, leather, wood, furniture and garden trimmings. On-combustible rubbish consists of glass, tin cans, aluminium cans, ferrous and other non-ferrous metals and dirt.
Special waste: Special waste includes street sweepings, roadside litter, and litter from municipal containers, catch-basin debris, dead animals and abandoned vehicles.
Ashes and Residues: These are materials remaining from the burning of wood, coal, coke and other combustible wastes in homes , stores, institutions , and industrial and municipal facilities for purposes of heating, cooking and disposing of combustible waste. These are referred to ashes and residues.
Solid waste collection
The element of collection includes not only gathering of solid waste, but also the hauling of waste after collection to the location where the collection vehicle is emptied (Kreith 1994). In the city of Thimphu in Bhutan the collection of solid waste from households, commercial set-ups were done in concrete receptacles placed at strategic points and conveyed by trucks. Accordingly, there were concrete bins and containers provided at various locations from where the waste was lifted for disposal. Individual bins/containers were also placed alongside the shops in certain areas, which were emptied directly into the trucks/tippers. This prevents people from dumping waste indiscriminately. However, the building of these concrete bins and containers may be expensive to do in Kenya and for this matter Kisauni.
It is the ultimate fate of all solid wastes whether they are residential waste collected and transported directly to the landfill site.
Solid waste management is a crucial practice in the maintenance of environmental health and beauty of an area. Sustainable solid waste management practices should be adopted in the area to ensure that, indiscriminate dumping and littering is curbed in the area. Informal sector should be recognized as plays an important role in the management of solid waste in the division. „Scavengers‟ and other informal solid waste collectors should be provide with the right and adequate equipment to make them more effective and efficient in performance of their duties.
- Adequate Resourcing of Waste Management Institutions: The waste management institutions should be adequately resourced by the CCM to ensure efficient and effective waste management in the area. The City Council of Mombasa should liaise with other corporate bodies like the United Nations Development Program (UNDP). With the support, adequate dustbin, and core waste management equipment such as compaction truck. People particularly in the low class residential areas should be made to pay for disposing their waste. This is because they are the very people who generate the waste. That is the „pay as you throw principle‟ should be introduced. All these should be done through education by letting residents know the importance of environmental cleanliness and how they can contribute to it. This will go to support the financial base of the waste management institutions.
- Putting in place an ideal waste management system that embraces a technical approach including collection and transportation plans, waste reduction, recycling and disposal plans. It should be improved by management and regulatory systems that embraces an institutional and financial approach including legal, private sector and public education and awareness plans.
- Encourage greater public involvement through intolerance to waste mismanagement. This will exert pressure on the authorities and waste management agencies to better their services to the division.
- NEMA should be active as close to 90% had no idea that NEMA offices are around the county and operate
- Waste collection efficiency by both private and public operators should be improved.
- Proper management of landfill. The landfill site should be properly managed to avoid heaping of waste and burning. Waste dumped in the landfill should be spread, compacted and covered with soil. This will prevent heaping of waste in the landfill. Furthermore, the landfill management should ensure that waste that is carried to the landfill does not contain fire.
- Support the formation of „scavenger‟ micro-enterprises, scavenger co-operatives to facilitate a strong financial support network for the scavengers to carry out their activities.
- Recognize the role of the informal sector in solid waste management.
- Legalize scavenging so that they do not have to perform their activities in a manner shrouded with secrecy and suspicion from the residents.
- Provision of dustbins and other means of collecting solid waste in the area.
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