CONCEPTUAL FRAMEWORK ON SOLID WASTE MANAGEMENT IN URBAN AREAS
2.1.2 Solid Waste
Another concept that calls for attention in as far as this study concern is the term solid waste. The term solid waste as used in this context may be construed by tracing the meaning of the word ‘solid’ independently and then construe the general meaning when it is qualified by the term ‘waste’. Macmillan English Dictionary for Advanced Learners42 defines ‘solid’ simply to mean a substance that is not a liquid.
Myneni43 defined solid waste to mean any garbage, refuse, sludge from a waste treatment plant, water supply treatment plant or air pollution control facility and other discarded material including solid, liquid, semi- solid or contaminated gaseous material resulting from industrial , commercial , mining and agricultural operations and from community activities , but does not include solid or dissolved material in domestic sewage. The solid waste includes garbage, paper, wood, cloth, plastic, iron scrap, food residue, and glass
39 JICA Study, Op. Cit. pg.17
40 Ibid
41 Ibid
42Shovel M (2007), Macmillan English Dictionary for Advanced Learners, 2nd Edition, A&C Black Publishers Ltd, London, pg. 1421
43 Myneni, Op. Cit. pg. 150
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containers as bottle, crockeries and other discarded materials from industrial operations, such as boiler slag and fly- ash.
Another author who attempted to define solid waste is Schubeler44who defined solid waste to include refuse from households, non-hazardous solid waste from industrial, commercial and institutional establishments (including hospitals), market waste, yard waste and street sweepings.
In Tanzanian context the meaning of solid waste is provided for under Section 345 which defines solid waste to mean non-liquid materials arising from Domestic Street, commercial, industrial and agricultural activities and includes refuse or garbage, non-liquid materials arising from construction and demolition activities, garden trimmings and mining operations m dead animals and abandoned cars scraps. This statutory definition of the term solid waste is exhaustive as it covers a wide range to reflect the concept.
2.1.3.0 Effects of Solid Waste
Billions of tons of solid waste are generated globally; cities in the developed countries produce more solid waste per capita than the cities that are located in the developing countries.46For instance, a typical American generates an average of 2Kgs of solid waste each day, 47whereas in Africa is approximately 0.5Kgs per person.48
Solid wastes released by cities are referred to as municipal solid waste (MSW). Solid waste affect environment in various ways especially when not properly managed, the following are the impact of solid waste on environment;-
2.1.3.1 Effect of Solid Waste on Terrestrial and Aquatic Life
The terrestrial organisms such as plants and animals are always exposed to risks of health and life due to pollution related to solid waste accumulation. For instance; - animals such
44Schubeler P (1996) , Conceptual Frame work for municipal solid waste management in Low income Countries ,UNDP/UNHCHS(Habitat)/ WORLD BANK/ SDC Collaborative Programme on Municipal Solid waste management in Low income countries.(Working Paper No.9), pg.18
45 Environmental Management Act [Act No. 20 of 2004]
46 Myneni, Op. Cit. pg. 150
47 Ibid
48www.encapafrica.org/EGSSAA/solidwaste pdf accessed on 28 November 2012 at 1350Hrs
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as cows and goats die of eating plastic wastes.49On the other hand solid and liquid wastes that accumulate in water bodies affect the physical, chemical and biological characteristics of the aquatic ecosystem.
The life form in the aquatic ecosystem is adversely affected by the solid waste accumulation and the impact can range from less reproduction and also reduction in total population of various plants and animals to the extinction of a few species which cannot survive in the changed environment.50
2.1.3.2 Effect of Solid Waste on Health
Domestic and Industrial solid wastes are dumped in residential areas, which causes unhygienic conditions and ultimately results in outbreak of diseases such as cholera and malaria51 For example;- coloured plastics are harmful as their pigment contains heavy metals that are highly toxic, some of the harmful metals found in plastics are copper, lead, chromium, cobalt, selenium, and cadmium.52
The effect of solid waste on health in Tanzania was given weight in the landmark case of Festo Balegele v. Dar-es-salaam City Council53 in which the court held that the City Council decision to locate the garbage dump near residential areas violated plaintiffs’
Constitutional rights to healthy environment. In his own words Lugakingira J (as then was) had this to say;-
“I have never heard it anywhere before a public authority or even an individual to go to court and confidently seek for permission to pollute the environment and endanger peoples’ lives, regardless of their number. Such wonder appears to be peculiarly in Tanzania but I regret to say that it is not any court to grant such a prayer. Article 14 of our Constitution provides that every person has a right to life and to protection of his life by the society. It is therefore a contradiction in terms
49 http://www.shareyouressays.com/110866/what-is-the-impact-of-waste-accumulation-on-terrestrial-aquatic-lifeaccessed on 28th November 2013 at 1405Hrs
50 Ibid, accessed on 28th November 2013 at 1410Hrs
51Myneni, Op. Cit. pg. 155
52http://edugreen.teri.res.in/explore/solwaste/health.htm accessed on 28 November 2013
53 Misc. Civil Case No. 90 of 1991 [High Court] (Unreported)
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and a denial of this basic right deliberately to expose anybody’s life to danger or what is eminently monstrous to enlist the assistance of the court in this infringement.”
2.1.3.3 Effect of Solid Waste on Landscape
Improper disposal of the solid waste in the highways and other places spoil the landscape to a great extent, this in turn affect the whole community.54Solid waste is one of the major causal factors for filthiness in most of the cities in the world. For instance; - cities like Mwanza, Arusha, Dar-es-salaam are adversely affected by solid waste pollution.
2.1.4.0 Solid Waste Management (SWM)
Solid waste management (SWM) is also defined under section 355 to mean an essential service that is provided to protect the environment and public health, promote hygiene, recover materials, avoid waste, reduce waste quantities, decrease emission and residuals and prevent spread of diseases.
Solid Waste Management also, refers to the collection, transfer, treatment, recycling, resource recovery and disposal of solid waste.56In its broad sense solid waste management may be considered as a cyclical process of setting objectives, establishing long- term plans, programming, budgeting, implementation, operation and maintenance, monitoring and evaluation, cost control, revision of objectives and plans.57Solid waste management can be attained vide adopting some strategies such as;-
2.1.4.1 Source Reduction
Source reduction is one of the fundamental ways to reduce solid waste. Source reduction involves using less material when making a product, reusing production on site designing products or packaging to reduce their quantity of waste thrown away.58Source reduction is the highest goal in the solid waste management hierarchy as the practice of source
54 Myneni, Op. Cit. , pg.155
55 Of the Environmental Management Act
56 Schubeler, Op. Cit. pg.3
57 Ibid
58 Myneni, Op. Cit. Pg. 155
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reduction benefits the environment through reduced energy consumption and pollution, conservation of natural resources, and extension of valuable landfill space. It can also have economic benefits by reducing costs associated with transportation, disposal or recycling of waste. Plus, source reduction can save money every day.59
Source reduction can be a successful method of reducing waste generation for instance at the individual level we can reduce the use of unnecessary items while shopping , buy items with minimum packaging , avoid buying disposable items and also avoid asking for plastic carry bags.60
2.1.4.2 Recycling
The term “recycling” means reusing some components of the waste that may have some economic value. Recycling diverts items such as paper, glass, plastic and metals from the waste stream. These materials are sorted, collected and processed and then manufactured, sold and bought as the new products.61
Recycling prevents the emission of many greenhouse gases and water pollutants, saves energy, supplies valuable raw materials to industry, creates job, stimulates the development of greener technologies, conserves resources for the future and reduces the need for new landfills and incinerators.62However, recycling is associated with technical and economic problems for example; - plastics are difficult to recycle because of the different types of polymer resins used in their production.
2.1.5.0 Solid Waste Disposal
Solid waste disposal is defined under The Environmental Management Act 63to mean the final stage in solid waste management system. The disposal of solid waste can be carried
59http://www.mde.state.md.us/programs/Land/RecyclingandOperationsprogram/SourceReduction/Pages/pr ograms/landprograms/recycling/source_reduction/index.aspx accessed on 28 November 2013 at 1523Hrs
60 Ibid
61 Myneni, Op. Cit. pg. 154-155
62 Ibid
63 Act No. 20 of 2004, Section 3
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out by several methods such as composting, vermicomposting, land filling and incineration;-
2.1.5.1 Composting
Composting is the biological decomposition of organic waste such as food or plant material by bacteria, fungi, worms and other organisms under controlled aerobic (occurring in the presence of oxygen) conditions.
The end result of composting is an accumulation of partially decayed organic matter called humus.64Composting involves degradation of organic wastes by micro- organisms in the presence of oxygen and provide a number of attractive features.65
The prepared compost is supplied to nurseries, kitchen gardens and horticulture department. The urban solid waste can be disposed of through a biotechnology-based
‘anaerobic digestion process’ which produce valuable organic manure and methane that can be used as fuel to generate power.66
2.1.5.2 Vermicomposting
Vermicomposting is a simple way of turning organic household waste into a useful soil conditioner and fertilizer for houseplants, gardens and lawns.67This technique is popularly known as ‘earthworm forming’.
It is an important bio technique for concerting solid wastes such as sewage sludge and domestic wastes into compost with the help of earthworm overtime. It requires less space than normal composting methods, and is therefore ideal for apartments and other settings in high density urban areas.68
64http://livinggreen.ifas.ufl.edu/waste/composting.html accessed on 28 November 2013
65 Myneni, Op. Cit. pg. 155
66 Ibid
67http://environment.alberta.ca/02984.htm accessed on 28 November 2013 at 1634 Hrs.
68 Myneni, Op. Cit. pg.155
24 2.1.5.3 Incineration
Incineration is an industrial process designed to reduce unwanted materials to simple solid and gaseous residues. It is the process of controlled burning of waste at high temperature (i.e. 850 Centigrade degree) in the presence of air. Emission of fly ash and other particles are often controlled by wet scrubbers, electrostatic precipitators and bag filters. It is a hygienic way of disposing solid waste and is more suitable if the waste contains more hazardous material and organic content.69
2.1.5.4 Land- filling
The term “land-filling” means a method of solid waste disposal in which refuse is buried between layers of dirt so as to fill in or reclaim low-lying ground.70It is the most common and cheapest method of waste disposal; landfills are engineered where solid waste is placed into the land.71