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CHAPTER 18 INTEGRATED WASTE MANAGEMENT

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Waste is a result of all activities of humankind, whether agriculture, industry, commerce, transport, medicine, or domestic. The more advanced the level of civilization, the greater the production of waste. Indications from available data are that
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  704 CHAPTER 18 INTEGRATED WASTE MANAGEMENT Carin Bosman Waste is a result of all activities of humankind, whether agriculture, industry, commerce, transport, medicine, or domestic. The more advanced the level of civilization, the greater the production of waste. 1  Indications from available data 2  are that the amount and hazardous nature of waste generated is in almost direct relation to the growth of the economy. National economies generate large quantities of different types of emissions, effluent, and ‘solid’ waste. 3  As a result of increases in population growth (social causes) and the process of industrialization 4  (economic causes), there has been increased pressure on natural resources and increased generation of enormous quantities of waste, 5  in solid, liquid or gaseous form, which can result in environmental degradation and pollution on global, regional and local scales (environmental effects). This in turn has detrimental effects on impacts on human health and economic activity (socio-economic effects). Some wastes may be recycled, some reused, some treated and concentrated, but eventually some residue remains which eventually find its way into the environment through emission to the atmosphere, discharge into a water resource or the sea, or disposal onto land. Integrated Waste Management entails the implementation of measures to ensure that the accommodation of these residues in the environment (irrespective if such accommodation is to air, water, or land) does not lead to adverse effects on human health and the environment. This Chapter will firstly address the concept of Integrated Waste Management, followed by a discussion of the current status of waste management in South Africa, including land-based waste disposal. The effect of emissions of waste to the atmosphere is addressed in the Chapter on Air Quality, and the effect of the discharge of effluent on water resources is discussed in the Chapter on Water Pollution. <A>18.1 BACKGROUND The term ‘waste’ is often used as a synonym for ‘pollution’, but it is important to note that ‘waste’ does not constitute pollution . Environmental Pollution has been defined as an unacceptable risk of harm to human safety, human health, or the environment. 6  The term ‘ waste’  refers to the unwanted materials or substances 7  produced by human activity which has the potential to cause pollution when released into the 1  Fourie, 1994:199 2 Law, 1996:101 3 Whyte, 1995 (BUILDING A NEW SOUTH AFRICA: VOLUME 4: Environment, Reconstruction, and Development: A Report from the International Mission on Environmental Policy http://www.idrc.ca/en/ev-9323-201-1-DO_TOPIC.html ) 4  Asante-Duah, 1993:1 5 Barnard, 1997:225, Fuggle and Rabie, 1994:1 6  Asante-Duah, 1993:2; Blackman, 1996:36; Noble, 1992: Vol. 4, 4-5 and others 7  Asante-Duah, 1996:2  705 environment, if causing a risk to human health, or exceeding the environmental carrying capacity 8 . These materials or substances could be solid, liquid, gaseous or radioactive. However, what is considered by one industry as a waste may very well be a useful resource for another. Different waste types are disposed of in different ways, ranging from dedicated engineered waste-disposal facilities to dilution in the natural environment (air or water). “Solid” wastes refers to materials with a low moisture content, and is usually disposed of on land; wastes with a high moisture content (effluent) are usually discharged into a water resource (usually after some form of treatment), but are often also disposed of on land (disposal), sometimes along with wastes of lower moisture content (co-disposal); and gaseous wastes are mostly vented into the atmosphere (emission). Some materials or substances have the potential to be harmful to human beings and to cause irreversible deterioration or damage to the environment, leading to air pollution (such as acid rain), surface-water and groundwater pollution, and soil pollution, or can cause aesthetic concerns. 9  These impacts can occur at any point in the waste life cycle , best illustrated by the Tchobanoglous 10  model,   below: Figure 18.1 The Tchobanoglous model for the Waste Life Cycle   This model supports the ‘cradle to grave’ approach 11 , which is founded in the basic scientific principle that matter cannot be created or destroyed, and that impacts on the environment should not only be considered at the point of disposal, discharge or emission, but also at the point of generation, and even storage of raw materials. The following examples illustrates this approach: Consider the generation of sewage in a domestic household, which could be stored in a septic tank before collection by a local authority, transportation to a pumping station, from where it is transported via a reticulation pipeline to a sewage treatment works. Potential pollution problems not only arise at the sewage treatments works, but could also arise at any point in the life cycle, such as at the septic tank, in an accident with the collection vehicle, at the pumping station, or in the reticulation network prior to arrival at the treatment works. Similarly with industrial waste, generated in the factory, stored in a skip, collected by the waste contractor, before transfer to a recovery plant, or during transportation to a hazardous landfill site, potential pollution problems could arise anywhere in this chain of events. In the same vein, transfer pipes for gaseous wastes can develop leaks and 8  NEMA section 2: Sustainable development requires the consideration of all relevant factors including that the development, use and exploitation of renewable resources and the ecosystems of which they are part do not exceed the level beyond which their integrity is jeopardised; 8  Protection of carrying capacity and biodiversity is addressed in section 2 of the National Environmental Management Act (NEMA) as follows: “(4)(a) Sustainable development requires the consideration of all relevant factors including the following: (vi) that the development, use and exploitation of renewable resources and the ecosystems of which they are part do not exceed the level beyond which their integrity is jeopardised; and (i) That the disturbance of ecosystems and loss of biological diversity are avoided, or, where they cannot be altogether avoided, are minimised and remedied”. 9  Blowers, 1994:72 10  Solid wastes engineering principles and management issues (1977). 11  NEMA section 2: Responsibility for the environmental health and safety consequences of a policy, programme, project, product, process, service or activity exists throughout its life cycle  706 pose a risk quite a distance from the actual emission stack. In addition, certain waste types, in particular waste that may be harmful to human beings, may be imported or exported, 12  and there are often other forms of transboundary flows of pollutants and waste (such as the movement of polluted air or water across national borders). It is hence important to consider not only the final destination of a waste as the only point where pollution occurs, but also all stages of the waste life cycle to appropriately manage the impacts associated with the waste. “ Waste management measures ” refers to measures implemented to reduce the effect of waste on health, the environment, or aesthetics, and to recover resources from the waste. These measures include waste minimisation, as well as waste separation, collection, transport, processing, recycling, treatment, and disposal, discharge or emission of waste materials, the monitoring of quantities of waste materials, their impacts on the environment, and implementing remedial measures where impacts have occurred as a result of poor waste management practices. Integrated Waste Management  refers to the integrated planning, implementation, monitoring, and review of these waste management measures to ensure sustainability and to prevent detrimental impacts on human health and the environment. <A>18.2 THE INTERACTION BETWEEN SUBSTANCES AND THE ENVIRONMENT  All substances and wastes have potentially hazardous impacts, 13  since almost any chemical could cause severe health impairment or even death, depending on the circumstances under which receptors are exposed to these substances. The hazards posed by some waste types are obvious due to their inherent physical or chemical characteristics, such as radioactive waste or carcinogens, and such waste types will definitely have a harmful effect on human beings upon exposure. Should they be managed under circumstances that will prevent the risk of such exposure, these wastes, although hazardous, will not have a detrimental impact. Other wastes may appear ‘harmless’ or ‘non-hazardous’ or even ‘inert’, but become a cause for concern as a result of the effects of chronic exposure or when they decompose, or due to the fact that they are disposed of in a particularly sensitive environment (for example, the disposal of ash in a wetland). It is typically these wastes that are often casually accommodated in the environment, and then cause worse pollution problems than the careful and proper disposal of the more harmful waste types. Waste may or may not be harmful depending on the circumstances under which it is managed. 14  This can best be illustrated by using an example of 10 ten-ton trucks loaded with dirty sodium chloride, which can be disposed of without any effects into the marine environment, but which will cause a serious pollution problem when disposed of in a wetland that is used as a drinking water source by a rural community. Hazardous or harmful waste is therefore any substance that results or could result in the risk of pollution being realised, when released into the environment. The aspects that will determine if the pollution will occur, depends on both the characteristics of the waste source itself, and the vulnerabilities of the receiving environment. Legal requirements are often quite specific regarding the classification and treatment of certain waste types, and even the specifications for the design or location of final emission or discharge or disposal facilities, but fail to address requirements for other aspects of the waste cycle, such as transfer pipelines and 12  Refer to the Basel Convention, of which South Africa is a signatory, for requirements relating to the movement of certain types of wastes across international boundaries 13  Hawkins, 1996:9, Asante-Duah,1993:8, Fuggle and Rabie, 1994:592 and others 14  Law, 1996:100  707 pumping stations. This is a serious concern, since release can occur anywhere along the transfer pathway, and it is not only the characteristics of the waste that will determine whether an impact occurs or not; it is also the characteristics of the receiving environment, both at the point of final disposal or discharge or emission and along the transfer pathways, which often run through sensitive areas. In considering the impacts of substances and wastes on the environment, it is thus important to address both the characteristics of waste sources, as well as vulnerabilities of potential receiving environments, as outlined below. <A>18.3 CHARACTERISTICS OF WASTE SOURCES Waste may be categorized and legislated in many different ways, such as according to its srcin (for example domestic, industrial, commercial, medical, construction, nuclear, agricultural), its chemical properties (for example inert, toxic, inflammable), or its physical properties (for example moisture content: Liquid waste or effluent and solid waste). ‘Solid waste’ is a collective term used for materials with lower moisture contents that result from human, industrial, mining, and agricultural activities (domestic waste has typically 45 per cent moisture content) and are usually disposed of on land. Several factors determine the hazard posed by the presence of substances in the environment. These include physical form and composition, quantity (volume), reactivity (flammability, explosion), biological and ecological effects (toxicity and concentration), mobility (potential to be transported in the various environmental media), persistence (accumulation), indirect health effects (pathogens and vectors), and pathways of transport and exposure. 15  Certain wastes represent special hazards and require appropriate treatment. For example, medical waste which may be contaminated with pathogens should be treated by means of incineration, and radioactive waste should be disposed in highly engineered and secured burial facilities. Radioactive substances vary in their level of activity and are hazardous because prolonged exposure to ionizing radiation often results in damage to living organisms, and the substances may persist over long periods of time. The identification of the types of wastes that could have a potential harmful effect is therefore the first step in the determining the potential risks associated with the release of such materials into the environment, as well as the management measures that can be implemented to prevent these risks from being realised. <A>18.4 IMPACTS ON THE RECEIVING ENVIRONMENT  As discussed above and illustrated in Figure 18.4, hazards and potential risks to human beings and the environment depend not only on the properties of the waste, but are also a function of the vulnerability of the receiving environment to handle the potential realization of the risk of an adverse impact on specific environmental components. Waste emission, discharge, or disposal on land can result in air, water, and soil pollution, although the most severe impact is normally on the water resource. 16   15  Asante-Duah, 1996:9 and Keller, 1992:270 16  Asante-Duah, 1996:154  708 <B>18.4.1 Impacts resulting from waste emission to the atmosphere (air pollution)  Air pollution is the contamination of the atmosphere by gaseous, liquid, or solid wastes or by-products that can endanger human health and the health and welfare of plants and animals, or can attack materials, reduce visibility, or produce undesirable odours. The disposal of waste to the atmosphere (emission) results from many industrial processes, and air pollution is associated with five main activities, namely:   Fuel combustion from stationary sources (eg power generation);   Fuel combustion from mobile sources (eg vehicles);   Industrial and chemical processes (eg coal processing, steel smelters);   Waste disposal, especially incineration, and   Land surface disturbance (eg mining and agricultural operations). The combustion of coal, oil, and petrol accounts for much of the airborne pollutants. When used as a method of waste management, in addition to heat, the products of incineration include the normal primary products of combustion—carbon dioxide and water—as well as oxides of sulphur and nitrogen and other gaseous pollutants; non-gaseous products are fly ash and unburned solid residues. The worldwide increase in the burning of coal and oil, especially since the late 1940s, has led to ever-increasing concentrations of carbon dioxide. The resulting ‘greenhouse effect’, which allows solar energy to enter the atmosphere but reduces the re-emission of infra-red radiation from the Earth, is now known to lead to a warming trend affecting the global climate. See Chapter 28 for more on climate change. The pH level, or relative acidity, of many freshwater resources has been altered so dramatically by acid rain that entire fish populations have been destroyed in some countries. Sulphur dioxide and nitrogen oxide emissions from coal-processing industries and power stations are causing acid rain in Mpumalanga and Mozambique. Sulphur dioxide emissions and the subsequent formation of sulphuric acid can also be responsible for the attack on limestone and marble at large distances from the source. The main impacts on the environment as a result of air pollution are:   Acid deposition (ie acid rain, which could be dry or wet);   Smog formation and visibility reduction;   Hazardous air pollutants such as volatile metals (eg lead), volatile organic components (eg benzene), and other heavy metals (eg mercury, arsenic);   Stratospheric ozone depletion, and   Global climate changes. From these impacts, it will be clear that the water resource will be the ultimate receiver of pollutants transmitted through the air since the Laws of Newton apply to the smallest dust particle: what goes up will come down as atmospheric outfall. This outfall pollutes the soil and, ultimately, our water resources, both. For further discussion on Air Pollution, and management measures aimed at the prevention there-of, refer to chapter 16. <B>18.4.2 Impacts resulting from waste disposal and discharge (water pollution) The recognition of the integrated nature of the environment, especially the hydrological cycle and the interrelationships between surface water, groundwater and atmospheric water, evolved only in the past 50 years. It has been shown throughout the world that the discharge of water containing waste (effluents)
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