Waste and Waste Management
Waste can be generally described as any item or material that is generated and disposed of or intended to be disposed of by a person that has custody of it. However, in addition to considerations of legal nature and geographical location of generation, different definitions of waste exist based on conditions under which they occur (Williams, 2005).
A process whereby strategic combination of methods are employed to efficiently regulate waste from source of generation up to the final disposal point is referred to as waste management, and the aim is to maintain a perpetually safe and healthy environment at minimal cost (Igbinomwanhia, 2011). Waste management has been identified as a challenge in many countries all over the world, much more so in developing countries, and a correlation has been identified between accelerated urbanization, population explosion, industrial development and rate of waste generation in cities found in such countries (Narayana, 2009; UNEP, 2005a).
Municipal Solid Waste
Every unwanted or non-useful solid substance generated in any human population is referred to as solid waste (Kaseva & Mbuligwe, 2003). Over time, consumption practices and activities of economic nature have resulted in generation of MSW (Cointreau, 2006, p. 9) which is basically waste that is generated from different sectors of a society such as households, educational, health and commercial institutions, public places, etc., and which is taken care of either directly or indirectly by the municipal or local authorities (Williams, 2005, p. 74). EEA (2009) defines MSW as: “…waste from households and other waste which because of its nature or composition is similar to waste from households (cf. the Land Directive). Some of this waste is biodegradable, e.g. paper and cardboard, food waste and garden waste. Biodegradable waste means any waste that is capable of undergoing anaerobic or aerobic decomposition, such as food and garden waste, and paper and paperboard (cf. Landfill directive)” (EAA, 2009, p. 14).
The components of such waste, often an assorted mix, are seldom the same for different areas due to factors ranging from standard of living and habits of residents to resources and climatic conditions found in each geographical location. MSW is often generated in urban areas and has contents that are organic and inorganic nature; the former being often found more in developing countries than the latter. The reverse is mostly the case in the developed part of the world and this is regarded as a significantly distinctive feature from the waste generated in their developing counterpart (Oteng- Ababio, 2011; United Nations Programme, 2005).
Sustainable Municipal Solid Waste Management
Sustainable development is an intergenerational concept. It has been defined as development that fulfills today‟s generation needs without blighting the opportunity for successive generations to fulfill their own (Idowu, Omirin, & Osagie, 2011). The whole process of collecting, transferring, treating, recycling, recovering resources and disposing solid waste in metropolitan areas defines municipal solid waste management MSWM (Ogwueleka, 2009). Sustainable MSWM should entail handling of waste (from collection, treatment to disposal) in a manner that ensures continued safety of public and environment (Adewole, 2009).
Global MSWM Frameworks and Approaches
Due to its significant role in providing safe environment and addressing public health concerns associated with waste generation, MSW is considered as an essential component of modern infrastructure in any society (Nabegu, 2010). The design of MSWM systems should consider and encourage reduction of waste, recycling and recovery of waste, utilization of appropriate waste treatment methods and more environmentally friendly technology as well as appropriate final disposal (Kofoworola, 2007).
SWM has over time evolved and improved to its current state in most developed countries; with these changes have come also the development of concurrent legislative requirements (Williams, 2005). As such, most have come up with contemporary national strategies for sustainable and efficient waste management; as a premier attempt at ameliorating solid waste disposal in the country, the United States developed the 1965 Solid Waste Disposal Act. This was amended under the Resource Conservation and Recovery Act. The latter represented how the country dealt with issues related to disposal of solid waste; although revised to meet present requirements, it also serves as the avenue through which a framework for environmentally friendly solid waste management (including MSWM) is developed via federal programs in the country (ibid).
In an Asian country such as China, policies and frameworks have also been promulgated as a means of combating the challenge of managing MSW. To improve on a previous management system in Hong Kong for example, there was an adoption of the Waste Disposal Plan developed in 1989, which had utilization of 3 large landfills at the core of its strategies for waste disposal; Waste Reduction Framework Plan was subsequently developed (Ko & Poon, 2009). In 2005, the government in Hong Kong established a MSWM policy framework for the region (A Policy Framework for the Management of MSW in Hong Kong). The goals to be achieved between 2005 and 2014 via the strategies employed within the framework include a reduction of MSW produced in the city by 1% every year, a reduction in the amount of MSW deposited in landfills (below 25%) by 2014, and an increase in the total rate at which MSW is recovered – first to 45% in 2009, then to 50% by 2014 (ibid).
In Europe several acts and treaties have come into existence; all having a common goal of environmental protection and amelioration, although with different concepts and strategies. The 1st , 2nd and 3rd Environmental Act (E.A)- underlined pollution containment from waste, pollution avoidance which underlined avoidance of waste, re-use, recycling and end disposal of MSW through environmental friendly methods respectively. Following this was the development of the 4t h E.A in which there was an introduction of a hierarchy as a continuous means of executing management of community waste in the European Union (E.U), there was also emphasis on the use of non- polluting technology during production. More recently is the harmonization of sustainable development, environmental regulations, and decision formulation with EU policies and strategies, as found in the 5t h and 6t h Environmental Act (Williams, 2005).
The Solid Waste Management Hierarchy
MSWM practices between countries are distinct; in most however, relevant services are rendered by the (local) government or private service providers and may be carried out by employing the hierarchy of waste management (UNEP, 2005b). The hierarchy is regarded as one of the important foundations of contemporary MSWM systems and has been popularly adopted for the development of policies related to waste management both on regional and national level, especially in developed countries (UNEP, 2005a). The hierarchy of waste management – defined by the 3Rs – reduce, reuse and recycle- stratifies options of waste management and focuses on maximum utilization of resources with minimum generation of resultant waste (UNEP, 2005b). The 3Rs refer to the reduction in the amount of waste being generated, the reuse of items prior to their being commissioned as waste, and the recycling of items once they become waste. An expounded version of this in the waste management hierarchy includes- waste prevention/reduction, reuse, recycling &composting, energy recovery, and finally landfilling.
The hierarchy‟s function is to aid in the management of waste whilst ensuring little impact on the environment; as such, it is employed in the development of policies for resource management, for handling challenges of landfill scarcity, pollution control (of water and air), and to safeguard public health (UNEP, 2005a). In most nations, prioritization of components in the hierarchy is alike- giving preference first to waste prevention, then reuse, recycling (including composting and material recovery), energy recovery and reduction of waste via methods such as incineration and finally landfilling (ibid).
Waste Prevention and Reduction
Waste Prevention occupies the topmost rung in the waste management hierarchy. It refers to the activities undergone with an item prior to being perceived as waste; these involve: decrease in the amount of waste produced via the prolongment of such item‟s life span and its re-use; decrease in associated environmental and public health impacts from waste produced; and decrease in quantity of noxious substances contained in products (European Commission, 2010). The concept of waste prevention cuts across the entire process a product undergoes- right from its obtainment in raw form, its manufacture, distribution, to its utilization and end of its useful life. While prevention or minimization may not be isolated to a certain stage in any product‟s life time, the more efforts directed at waste prevention in the earlier stages of a product‟s lifetime, the less impact they have on the latter stages (ibid).
In essence, effective waste prevention at source is based on factors which include adoption of suitable practices, adjustments in the usage of raw materials, as well as in technology and production processes. At the domestic level, such would include making suitable decisions in the management of the household (Williams, 2005). Much focus has been given to food waste which is a major component of household waste. Such waste may be esculent (for example, potato peels, food that may have lost freshness) or non-consumable (for example, fruit peels) in nature. Some waste generated in the former group could also be prevented from occurring (avoidable waste); this however does not extend to those which may only be consumed following strict preparation methods (European Commission, 2011). Generation of non- consumable wastes may not be prevented based on their nature and these include calciferous parts of animal products such as shells or bones (unavoidable waste). Still pertaining more to food waste, prevention translates basically to purchasing only what is required to meet one‟s needs at any given time and maximizing the usefulness of what is purchased (ibid).
Following the hierarchy, the next best option for SWM is re-use and this encompasses the utilization of an item after its initial use, either for a purpose similar to that which it was intended or for an entirely new one. This is exemplified in the reutilization of bottles (of beverages) or plastic bags from stores (Williams, 2005).According to the European Commission (2010, s. 48), reuse refers to “… any operation by which a product or its components, having reached the end of their first use, are used for the same purpose for which they were conceived, including the continued use of a product which is returned to a collection point, distributor, recycler or manufacturer, as well as reuse of a product following refurbishment;”
As such, the reduction of solid waste extends to reuse as the latter slows down the entrance of an item into the waste stream, as well as prevents the amount of items that eventually become waste (European Commission, 2010). Eventually, such result in the reduction of virgin materials and energy utilized in production of items, however, it also means that items have to be made sturdier in order to be used more than once; hence the utilization of more resources during production phase. These in addition to the energy expended on collecting and transporting such products may have negative effect on environment (Williams, 2005).
MSW materials which arise following consumption may be recovered and processed into useful items, bearing in mind the cost effectiveness, marketability and environmental impact it may have (Williams, 2005). The recycling process includes collection, segregation and processing of waste with productive value (Pattnik & Reddy, 2009) as such inorganic fractions of MSW (paper, metal, plastic, glass materials) may be recycled (Williams, 2005). This option‟s suitability depends on inherent conditions of the environment under consideration. Hence, energy resources utilized during the process of recycling as well as the resultant pollution should be minimal in comparison with the utilization of fresh production material. The effectiveness of cost and marketability of products from such activity should also be ascertained (ibid).
Recovery of inorganic materials from MSW has been identified as a key component in the management of waste (Sharholy, Ahmad, Mahmood, & Trivedi, 2007). In some developed parts of the world, recycling activities have been reported to be quite high. The rates in Germany and Austria for example, go beyond 25%, with Austria being reported to have maintained composting rates of about 40% since the early 90s (EEA, 2007) and Brazil having material recovery rates as high as approximately 41% (Troschinetz & Mihelcic, 2008). For most of such advanced countries, recycling is typified by curbside programs through which collection and segregation of recyclables are carried out (ibid).
Recycling is mostly utilized within the context of the usage of solid waste materials for other purpose than it was originally intended- reuse, such are often segregated from other types of waste either via specified receptacles and vehicles for collection, or straight from unsegregated waste (Magutu & Onsongo, 2011). For most developing countries, recycling rates are low and dominated by the uncontrolled salvaging of inorganic materials by the non-formalized sector made up of scavengers (UNEP, 2005a).
Organic components in MSW (i.e. waste of food and garden origin) are considered useful composting material (Williams, 2005). Composting is a process which could decrease MSW by an average of almost 68 % of its original volume (Sharholy, Ahmad, Mahmood, & Trivedi, 2007). The process has been defined as the:
“… biological decomposition of biodegradable solid waste under controlled predominantly aerobic conditions to a state that is sufficiently stable for nuisance-free storage and handling and is satisfactorily matured for safe use in agriculture” (UNEP, 2005a, p. 197).
The end product, compost, may be utilized in the conditioning of soils meant for agricultural purposes; its use in this manner gives the soil a stable nutrient source (nitrogen, potassium and phosphorus) that is gradually tapped from, and aids its water retention capacity. The usefulness of compost also extends to coverage material for landfill sites as well as material for land reclamation from mining activities and incidents of erosion (Ali, 2004; UNEP, 2005b).
With regard to reducing the amount of waste that ends up in solid waste disposal sites, composting is considered a more viable and sustainable option for developing countries due to the high organic fraction of waste generated (Troschinetz & Mihelcic, 2008) and resource constraints in such countries (UNEP, 2005a). An advantage of this option when compared with other options in the SWM hierarchy, is its employability in a catalogue of conditions due, inter alia, to its non-rigid requirements, consequently, methods of composting range from the unsophisticated which may be found in developing countries to the highly sophisticated used in developed countries (ibid). However, the success of composting for environmental benefits (i.e. reduction of organics in the MSW stream) and economic benefits (e.g. from sales of recycled organic waste to compost- for agricultural soil improvement) rests mainly on segregation of waste at source, in which case households have important roles to play as they are major producers of organic waste (Ali, 2004) The organic fraction of MSW may also be useful in the production of carbon dioxide and methane gas in a process called anaerobic digestion. The process is achieved in an enclosed environment under anaerobic conditions (environment lacking in oxygen) with an external medium for the supply of heat. The methane gas thus generated may be contained and utilized for the production of steam or power; the gas may also serve as fuel upon purification (UNEP, 2005b).
MSW contains organic components which are combustible. Thus, energy could be gained from incineration of waste or landfill gas combustion, which may be used to generate electric power (from steam under high thermal conditions) or produce heat for buildings (through boilers) (Williams, 2005). As such, the process of converting solid waste of organic nature into other useful forms such as gas, heat, steam and ash residues via combustion is referred to as incineration and such process is carried out in places often referred to as Waste-to-Energy (WtE) plants (Magutu & Onsongo, 2011).
In the reduction of solid waste volume by 70 to 80% lies also a main advantage of this method of waste disposal, as this minimizes the quantity of waste that is eventually sent to the land fill. Consequently, for nations where land space challenges exist for example, Japan and Singapore, incineration is a popular waste disposal option (Magutu & Onsongo, 2011, p. 6). Further, following the introduction of bans and taxation on landfills with regard to biodegradables, countries such as Sweden and Denmark in the European Union (EU) have been reported to be the most active in the use of incineration for disposal of MSW (EEA, 2007). According to Williams (2005), simultaneous production of heat and power (combined heat and powers) from landfill gas and incineration makes optimum energy recovery from (organic) waste achievable. However, in comparison with their initial forms, new products that arise from incineration of waste (liquid and air discharge inclusive) pose more difficult management and environmental challenges- a development which has increasingly seen many countries banning this option for waste management (Narayana, 2009).
Landfilling is the deposition of waste either in a specific land area with the goal of preventing such waste from impacting negatively on the environment (Narayana, 2009). A landmark in the EU strategy for waste management was the development of the 1999/31/EC directive on waste landfilling. The landfill directive has its roots in the hierarchical prioritization of waste management options- giving maximum preference to prevention of waste, with reuse, recycling, recovery options following and landfilling having the least priority. Realizing how landfilling could be impactful on the environment through greenhouse gas (GHG) emissions and other forms of pollution (through soil, surface and ground water) and how inadequate space could be a challenge, the landfill directive discourages heavy reliance on this option by setting goals which gradually reduce the quantity of municipal waste that is relegated to the landfill until the year 2016 (EEA, 2009), when a reduction in the quantity of biodegradable waste sent to the landfill should be 65% in comparison with the amount that went for landfilling in 1995 (Bogner et al, 2007)
Despite being widely considered as the least desirable option, the most prevalent approach to the disposal of waste globally has been the utilization of landfills. This remains an important aspect of the SWM plan of most countries and varies in structure; ranging from sanitary landfills, to semi-controlled landfills and uncontrolled (or open) dumpsites (Remigios, 2010). Sanitary landfills are designed according to specifications which help to ensure minimal impact of disposed waste on the environment. As such, they are structured for leachate containment and treatment, as well as management of greenhouse gases (carbon dioxide and methane) which are produced in the event of waste decomposition. Such well-structured landfills exist in nations with developed economies (ibid). Generally in North America and other countries Australia and New Zealand, the most utilized option for waste disposal on a large scale remains landfilling. However, such is highly controlled and goes with adherence to corresponding legislative landfilling and air quality requirements (Bogner et al, 2007). For highly industrialized Asian countries such as Singapore where space for perpetual landfilling is a challenge, this option is only utilized when other means for waste disposal are not feasible (Zhang, Keat, & Gersberg, 2009).
In the global South, partly operated waste disposal sites, referred to as semi-controlled landfills and uncontrolled dumps exist. For the former, compaction of waste and subsequent covering with topsoil is carried out. However, structures for leachate and greenhouse gas containment as well as restriction on the type of waste being deposited are absent. Uncontrolled dumping is the main and favored means of solid waste disposal in a majority of nations on the African continent. This involves disposal of waste on open, non-structured area of land without considerations for environmental impact (Remigios, 2010).
Table of contents :
1.1 Description of SWM in Nigeria
1.3 Justification of Study
1.5 Research Questions
2.1 Waste and Waste Management
2.1.1 Municipal Solid Waste
2.1.2 Sustainable Municipal Solid Waste Management
2.2 Global MSWM Frameworks and Approaches
2.3.1 Waste Prevention and Reduction
2.3.5 Energy Recovery
2.4 The Case of Lagos State
2.4.2 Recycling, Resource Recovery and Incineration
2.5 Solid Waste Management Structure in Lagos
3. MATERIALS AND METHODS
3.1 Description of Study Area
3.2 Methodological Framework
3.3 Data Collection and Approach
3.3.1 Choice of Stakeholders
3.3.2 Size Selection
3.3.3 Stakeholder Interviews
3.3.5 Household Interviews and Observation
3.3.6 Private Service Participation Operator Interviews and Observation
3.3.7 LAWMA Interview
3.3.8 Scavenger Interview and Observation
3.3.9 Solid Waste Disposal Site Observation
3.4.1 Analysis of Data
3.4.2 Limitations in the Field
4.1 Classification of Households
4.2 Components of Household Waste in Lagos
4.3 Changes in Household Solid Waste
4.4 Results Following the Waste Hierarchy
4.4.1 Reduction of Waste from Households
4.4.2 Reuse of Items
4.4.3 Recycling of Items
4.4.5 Incineration of Household Waste
4.5 Household Storage of Solid Waste
4.6 Collection and Disposal of Household Waste
4.6.1 Level of Satisfaction on Collection Services
4.7 The Private Operators and their Challenges
4.8 Disposal Activity at Soluos Waste Disposal Site
4.9 Olushosun Waste Disposal Site
4.9.1 Leachate Control and Gas Capture
4.9.2 Scavenging Activity at Solid Waste Disposal Sites
5. ANALYSIS AND RECOMMENDATION
5.1 Volume, Content and Source Segregation
5.2 Dynamics in Solid Waste Collection
5.2.1 Willingness to Pay for Improved Waste Collection
5.3 Dynamics in Reduction, Reuse and Recycling
5.4 Potentials Following the Solid Waste Hierarchy
5.4.1Potentials for Reduction and Reuse
5.4.2 Potentials for Recycling
5.4.3 Potentials for Composting
5.4.5 Potential for Improved Solid Waste Disposal Site