The Environmentalist 18, 67±75 (1998)
Land use and solid waste generation in Ilorin, Kwara State, Nigeria J.F. OLORUNFEMI* AND C.O. ODITA Geography Department University Of Ilorin, PMB 1515, Ilorin, Nigeria
Summary Solid waste collection services in Ilorin, Nigeria are shown to be unsatisfactory. The poor service is related to rapid population growth, insuf®cient data and inconsistent government policies. Surveys have been conducted to assess the quantities and types of solid waste and to show how these, in part, vary according to the nature of the land use and the properties being served. Suggestions for an improved service are offered. Introduction
Background to the present study
The rapid rate of urbanization in Nigeria and its associated problems has been well documented (e.g. Mabogunje, 1968; Ayeni, 1978; Sada, 1980). Any urban policy must aim to solve the complex urban problems created by rapid growth. The environmental aspects of Nigerian urban policy are particularly deserving of attention for they impact directly on the living conditions in the cities. The generation of solid wastes is one such problem, created by rapid population growth coupled with inecient waste disposal techniques and aggravated by inconsistent waste management policies. The problems of refuse generation, collection, disposal and general environmental sanitation are not new as a topical issue in Nigeria (see, Adedibu, 1983, 1984, 1986). Indeed the national Nigerian environmental sanitation day, ®xed for every last Saturday of the month (between the hours of 7 and 10 a.m.), is evidence of the commitment on the part of the government to a clean environment. In 1984, the government of Kwara State enacted an additional environmental sanitation edict which made it imperative for every person to also clean their environment on every second Saturday of the month (between the hours of 7 and 9 a.m.). The main objective of these eorts is to keep the city clean of ®lth, rubbish and refuse of any kind or description. However, the government's policy formulation and implementation has not always been consistent.
The causes of the poor environmental condition of most Nigerian cities have been attributed, among other factors, to the lack of proper disposal of wastes (Sule, 1981; PAI Associates; 1982; Adedibu, 1986; M.O. Filani and S.I. Abumere, unpublished). Although waste may occur in solid, liquid and gaseous states, the most conspicuous of these is solid waste because it can be seen and perceived. Indeed, solid waste constitutes a nuisance to human life and the environment, if not properly stored, collected and removed. Although several attempts have been made to manage solid wastes eectively by the Nigerian waste management authorities, factors such as a lack of equipment and solid waste data, personal and environmental hygiene, the uncooperative attitude of members of the public and a lack of consistency in policy implementation have often been highlighted as problems militating against their success. The most conspicuous and probably the most important of these problems is the lack of solid waste data and, particularly in Ilorin, the inconsistency of government policy. The data problem is important because solid waste management is best undertaken when based on reliable data about solid waste generation rates at the local level (Berry, 1979). Indeed, the problem of solid waste is a dynamic one and so it deserves continuous monitoring (Adedibu, 1986). The lack of solid waste data has resulted in inadequate planning for solid waste management (PAI Associates, 1982; Onokerhoraye, 1985), which in turn explains the indiscriminate dumping of wastes in the roads, stream channels, bushlands and open spaces in most Nigerian cities (Sule, 1981; Adedibu, 1983; Ayoade, 1983; Folarin, 1995; Ibitoye, 1995). The consequences of such
* Dr J.F. Olorunfemi and Mr C.O. Odita are members of sta of the Department of Geography at the University of Ilorin.
0251±1088 Ó 1998 Chapman & Hall
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classes, namely domestic, municipal, industrial, agricultural, institutional, pesticide, residential and hazardous wastes. These classes of solid waste relate to their origin. Cargo (1978) had a simpler fourfold classi®cation even though this was also based on the source of the wastes: from domestic, municipal, commercial and industrial sources. Berry (1979) shared the same view in terms of solid waste classi®cation by origin as Cargo (1978), but went further to state that the wastes vary in quantity and composition in every society. It can be deduced from the de®nitions that solid waste composition depends on the land use or land-related activities within a speci®c area.
waste dumping constitute health and environmental hazards. This problem is further compounded in urban areas by the rapid population increases. For instance, in Ilorin, in 1952 the population was 41 000, but was estimated to be 320 000 in 1973 (Olorunfemi, 1982), 477 500 in 1980 (Adedibu, 1985) and 572 178 in 1991. This trend is not peculiar to Ilorin alone. Indeed, it has been estimated that the populations of most state capitals in Nigeria are growing at a rate of 6% per annum (Falodun, 1985). There is therefore a need for social scientists to study waste generation, in particular in Nigerian urban centres. The present study is aimed at ®lling this gap. It is the objective of this paper therefore to estimate the amount of solid waste generated in Ilorin with a view to providing some of the much needed data on waste generation for planning and management. Speci®cally, the authors have examined the spatial pattern of solid waste generation and its composition; in addition, the factors responsible for the observed pattern of waste generation by type and the relevance and eectiveness of waste dumpsters in waste management have been reviewed. Suggestions are made for more eective waste management techniques.
Methodology Two main instruments were used in the collection of data for this research. The ®rst involved the measurement of the wastes generated. Waste was sorted out into types (leaves and nylon, bottles, tins and cans, waste food, waste paper and other wastes) and the weight of each type was determined (Environmental Protection Agency, 1976; Ramastry, 1985). Questionnaires were designed to collect information on the characteristics of the respondents and their waste generative capacities. In addition, a questionnaire was designed to elicit information on waste collection and disposal practices in Ilorin. A preliminary study of the land use map of Ilorin was carried out. This was updated through a ®eld survey. On the basis of this land use map, Ilorin was divided into ®ve land use types, namely residential, commercial, educational, industrial and recreational. The sample size of each land use type was determined in two stages. The sample sizes of the residential and commercial land use areas were estimated from the land use map, using the proportion of land devoted to each use determined by the dot grid method (Birth, 1964; Olorunfemi, 1982). A minimum of 10% of this proportion was randomly selected. The sample sizes for the industrial, educational and recreational areas were determined by preparing a list of the industrial sites, educational institutions and recreational centres. A minimum of 10% of each establishment type was also randomly selected. In all, a total of 300 questionnaires was administered.
Solid waste: de®nition and classi®cation Solid waste can be de®ned as useless, unwanted or discarded material with insucient liquid content to be free ¯owing (Environmental Protection Agency, 1972). The Hopkinsville Christian County Commission (1976) de®ned solid waste as the residual from homes, businesses and institutions and referred to it as trash, garbage, rubbish, refuse, discards and throwaways that enter a local system, for collection and disposal. These may be in the form of wrappers, papers, tins, cans, plastic containers and junk which includes such items as old refrigerators, stoves, lanterns, tables, beds, etc. (Ebomoyi, 1977). In general, therefore, solid waste can be de®ned as the non-gaseous and non-liquid wastes resulting from a wide range of community, industrial, commercial and agricultural activities (Adedibu, 1983). The classi®cation of wastes is no more controversial than waste de®nition. For instance, Adedibu (1985) grouped solid wastes into eight
Table 1. Solid waste generation and composition in residential areas of Ilorin, Nigeria in 1986 Socio economic category of households
Waste leaves and nylon (%)
Bottles, tins and cans (%)
Waste food (%)
Waste Paper (%)
Other materials (%)
Total (%)
Low Medium High Total
9 4 1 14
3 1 6 10
21 8 18 47
4 1 2 7
13 2 7 22
50 16 34 100
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Land use and solid waste generation in Nigeria Table 2. Residential areas and percentage solid wastes by type in Ilorin, Nigeria in 1991 Residential area
Waste leaves and nylon (%)
Bottles, tins and cans (%)
Waste food (%)
Waste paper (%)
Other materials (%)
Total (%)
ORA NRA GRA
12.5 24.2 15.0
11.7 8.3 14.2
30.0 25.0 30.1
27.5 26.7 22.5
18.3 15.8 17.5
100 100 100
In the case of the residential areas, two sets of data generated at dierent periods were employed. The ®rst set was collected in 1986 (Table 1), while the second set was collected in 1991 (Table 2). In the latter case, the residential areas were further divided into three zones (Onokerhoraye, 1985), namely old residential area (ORA), new residential area (NRA) and government residential area (GRA). Fifty structured questionnaires were administered in each of the three wards typical of the residential zones selected for this stage of the study. A systematic sampling technique was used in selecting the samples. The data collected were then subjected to dierent statistical analyses using analysis of variance, multivariate correlation and stepwise multiple regression techniques. Solid waste generation and composition Figures 1 and 2 show the spatial variations of solid waste generation and composition according to land use types in Ilorin. The highest mean generation rates, averaging 195 kg per day per industry, were found in the industrial areas. This was followed by educational areas with a mean of 26 kg per day per school, while recreational areas generated 18 kg per day per centre. The commercial and residential areas produced 1.08 kg per sta or shop and 1.20 kg per household, respectively. The existence of spatial variation in solid waste generation in Ilorin was further con®rmed statistically using the analyses of variance (ANOVA) technique. The result (signi®cant at the 1% level) indicated that there were dierences in the mean waste generated by dierent land use types. The t-test further con®rmed that there were variations in the mean solid waste generated between the dierent land use types. Residential areas In the residential areas, the solid waste generation and composition diered from one socioeconomic zone to another (Table 2). In general, 50% of the solid waste generated in the residential areas of Ilorin is produced in the low socioeconomic zones while the high socioeconomic districts and medium socioeconomic areas generate approximately 34% and 16%, respectively. The variations in the solid waste generation and composition in the
residential areas would appear to follow the taste and consumption patterns of the people, which in turn depend on their socioeconomic status. The higher proportion of waste food generation in the low socioeconomic areas would appear to occur as a result of a lack of appropriate food preservation techniques. Unlike those persons in the high and probably the medium socioeconomic groups, freezers and fridges commonly used for the preservation of left over food may not be available for those in the low income group. A correlation coecient of 0.54, signi®cant at the 1% level of probability, was found between the number of people per household and the total waste generated. This gave the impression that the higher the number of people per household, the greater the amount of solid waste generated. However, only approximately 27% of the variation in the total solid waste generated in the residential areas could be explained by the number of people per household. Other factors, such as marital status, income, sex, educational background and occupation, all cumulatively increased the variation by only 5±32% of the total explained variation. It would appear, therefore, that waste generation does not have a direct relationship with household size. In the 1991 survey (Table 2), food and paper waste constituted the largest components of the solid waste generated in the ORA, while nylon and leaves (12.5%) and bottles and tins (11.7%) constituted the least wastes generated. In the NRA, however, paper waste was the largest solid waste generated (approximately 27%). This was closely followed by food (25%). It is also important to note the proportion of nylon and leaves generated (24%) while bottles and tins constituted only 8.3%. The GRA had 30% of its waste made up of food waste. This was followed by paper (22.5%), while leaves and nylon and bottles and tins constituted 15 and 14.2%, respectively (Table 2). The high percentage of food waste in Ilorin should be a cause for concern. However, since there was no dierentiation between cooked and uncooked food waste, it was not possible to isolate the contribution of food peels (e.g. yam) to the amount of food waste observed in the research. While food waste in the ORA may be explained in terms of the general attitude towards food management by the indigenous people, who are 69
Olorunfemi and Odita
Fig. 1. Land use and solid waste generation in Ilorin, Nigeria.
mainly farmers and traders in food items and who perhaps lack the storage facilities as observed earlier, that of the GRA can only be associated with `auence'. If the survey were to be carried out after the increase in fuel prices of 1994 such as at the present time, the picture would possibly be dierent, because the middle class would appear to have been eliminated in Nigeria. Commercial areas In the commercial areas, the solid waste generation and composition varied from one commercial area to another (Table 3). The reason for this observation could be found in the variation in socioeconomic and demographic factors and dierences in the commodities sold. In terms of demographic factors, a correlation coecient of 0.39 was found between the number of stall/shop 70
attendants and the total solid waste generated. However, the stepwise multiple regression analysis, showed that only 24% of the variations in total solid waste generated could be explained by socioeconomic and demographic indices such as the number of stall/shop attendants, and educational background and sex of the respondents. It would appear that other factors, such as the type of goods sold, size of shop, etc., rather than the socioeconomic and demographic indices measured in this study, accounted for the type and amount of waste generated in this area. Educational areas Table 4 indicates that the highest amount of solid waste was generated in secondary schools. The factors responsible for the variations in waste in the educational areas were the total number of sta, The Environmentalist
Land use and solid waste generation in Nigeria
Fig. 2. Land use and solid waste composition in Ilorin, Nigeria.
and students and the areal coverage of the institutions. These factors, in that order, explain 98% of the variation in the total amount of solid waste generated in the educational sectors of Ilorin. Industrial areas In the industrial areas, spatial variations also existed in terms of the solid waste generation and composition. The composition of the wastes varied so much that it could not be classi®ed into
groups except in cases where the industries had similar products (Table 5). For instance, the wastes generated at Matchco included skillets, splints, green shaped papers and inner boxes. At Coca Cola, bottle tops, broken bottles, wooden crates, etc., were some of the wastes generated. Variations in the solid waste composition in the industrial areas could therefore be attributed to dierences in the types of raw materials used, their products and the product packaging methods of the industries. 71
Olorunfemi and Odita Table 3. Solid waste generation and composition in commercial areas of Ilorin, Nigeria in 1986 Commercial centres Emirs market Baboko market Ipata market Station centre Sango market Total
Waste leaves and nylon (%)
Bottles, tins and cans (%)
6.0 1.2 1.3 0.9 0.2 9.6
1.7 2.2 0.0 1.2 2.3 7.4
Waste food (%)
Waste paper (%)
Other materials (%)
Total (%)
7.0 4.2 8.0 3.5 0.9 24.0
5.0 8.5 2.6 1.6 3.2 21.0
9.5 7.3 4.5 1.5 2.4 38.0
29.3 23.2 16.4 2.2 9.0 100.0
Table 4. Percentage distribution of waste generation and composition in educational areas of Ilorin, Nigeria in 1986 Institution
Primary Secondary Kwara Tech Kwara College of Education University Total
Waste leaves and nylon (%)
Bottles, tins and cans (%)
Waste food and fruit peels (%)
Waste paper (%)
Other materials (%)
Total (%)
0.00 0.00 0.00 0.00
4.70 5.52 5.00 0.00
3.98 11.67 6.73 3.46
5.00 6.30 3.26 2.06
3.75 7.26 0.00 3.43
17 31 15 9
2.68 2.68
5.88 21.10
15.69 41.50
3.43 20.00
0.00 14.40
28 100
Table 5. Daily solid waste generation in industrial areas in Ilorin, Nigeria in 1986
associated with disposable consumable items usually available in recreation centres.
Name of industry
Waste dumpsters and waste disposal in Ilorin
Matchco Phillip Morris Coca-Cola Tate & Lyle Unifoam Global Soap Kwara Furniture Pepsi-Cola Total
Total waste generated per day (kg)
% of total waste generated
750.00 300.00 262.10 91.20 1.10 7.00 13.30 125.00 1549.70
48.00 19.00 17.00 5.88 0.07 0.45 0.85 8.02 100.00
Recreational areas The data collected from the recreational areas also depicted spatial variations in the solid waste generation and composition (Table 6). The volume of solid waste generated under each recreational area varied with the volume of users. However, the stadium, amusement park and Agba Park would appear to have had a decreasing number of callers or users in that order. An interesting aspect of waste generation in this area was the fact that most of the waste consisted of bottles, tins and cans. This is probably not surprising because these are waste products that are 72
Waste disposal is generally poor in Ilorin. Where waste disposal facilities are available, the facilities are such that they collect water during the rainy season, which adds to the weight of the waste, increases waste odour and provides a good breeding environment for insects and other microorganisms that are injurious to health. In the early 1980s the Kwara State Government constructed 100 refuse dumpsters (2.4 m ´ 2.4 m) located in dierent parts of Ilorin (Fig. 3). The nearest neighbour statistics
Rn 1:02 indicated that the dumpsters were randomly located. In the GRA, where there was a higher proportion of dumpsters, only approximately 10% of them were located within 100 m of homes. The implication of this is that the dumpsters are not easily accessible to the residents. Regrettably, the dumpsters are not large enough to contain the volume of waste generated in the neighbourhood. Out of the 100 dumpsters constructed, 90 had been destroyed, cancelled or fallen into disuse by 1991. The destruction and cancellations were made partly because of the inadequate size but also because of misuse by members of the public. At times, the dumpsters served as public toilets for some people. Some of the refuse dumpsters had collapsed because of the poor quality of the construction The Environmentalist
Land use and solid waste generation in Nigeria Table 6. Solid waste generation and composition in recreational areas of Ilorin, Nigeria in 1986 Recreational centres
Waste leaves and nylon (%)
Bottles tins and cans (%)
Waste food (%)
Waste paper (%)
Other materials (%)
Total (%)
Agba Park Amusement park Stadium Total
0.7 0.5 19.5 21.0
5.0 19.5 4.0 28.0
5.5 6.5 5.0 17.0
0.0 0.0 20.0 20.0
0.0 0.0 14.0 14.0
11.0 26.5 62.5 100.0
The problem of solid waste has been identi®ed. In terms of its composition, food waste constitutes the largest percentage of solid waste generated in the residential areas of Ilorin. Socioeconomic and
demographic indices have been shown to in¯uence waste generation by land use type. Environmental factors also play an important role in the explanation of the variation in solid waste generation and composition. Certain food items or consumer goods are seasonal in nature. For example, yams, though available throughout the year, are abundant in the rainy season. Therefore, greater amounts of yam peel are to be expected as waste in the rainy season as compared to the dry season. Similarly, fruits such as mangoes, cherries, oranges, etc., are abundant at certain times of the year. More fruit peel and left over food is generated when speci®c food items are abundant and consumed in large quantities. The present study reveals that the most important aspect of waste management would appear to be the education of the people on the need for personal and environmental hygiene. The situation in which residents rush out during rainstorms to empty their waste into the gutters so that the rain run-o can act as an agent for transportation of the waste, does not augur well for a good environment. The wastes end up being trapped in the gutters thereby blocking the free ¯ow of liquid wastes, euent and run-o. The streets are left ¯ooded while large amounts of waste of all types are left on the roads after each rainfall (Oyegun, 1983). There are, of course,
Fig. 3. An example of the many refuse dumpsters constructed in Ilorin, Nigeria.
Fig. 4. A typical disused and/or partially demolished dumpster in Ilorin, Nigeria.
materials and workmanship. The ability of the dumpsters to retain rain water is yet another factor that has probably contributed to their high rate of destruction. The dumpsters have become insect and micro-organic breeding grounds. Some of the dumpsters were located badly. Some were located directly opposite houses or close to where food items were sold in the open. This resulted in an unsightly environment. Their location per se would not have constituted an environmental hazard, but because of the usually irregular clearing of the dumpsters and the technique of this clearing, unsightly situations were unavoidable. It was not surprising, therefore, that the government went ahead with demolishing most of the dumpsters. Figure 4 typi®es the situation with many of the dumpsters, where the inscription `Do not dump refuse here ± Order, MOH' is a common sight. This is a case of ineectiveness of government policy, apparently indicating a lack of proper conception, planning, coordination and implementation. Conclusions and suggestions
73
Olorunfemi and Odita
environmental and ®nancial implications to this practice. Any environmental campaign or education must of necessity be followed by a commitment on the part of the government. Field evidence has indicated resistance and/or apathy on the part of the people towards the monthly or bimonthly environmental sanitation days because of their compulsory and coercive nature and the techniques of implementation. It is suggested that eorts should be made to provide functional waste dumping sites with regular and frequent collections. The government may in fact not be the best agent to collect refuse, for the house to house collection of waste from residential areas could be farmed out to private contractors or waste management consultants. If, on the other hand, the government is not ready to enter into a contractual agreement in waste management, adequate ®nancial provision should be made to make the environmental agency in the state eective. Although wastes from other land use types do not suciently constitute a nuisance at present, eorts should be made to prevent them becoming one. Schools and markets should have a regular waste collection service. The state environmental agency should be given this responsibility, unlike the present situation where the proper de®nition of roles and responsibilities is not clear between the ministries of education, local government and health and the environmental agency. Whatever the decision of the government is as to who should collect the waste, its disposal remains important. Land®ll is suggested because large areas of excavated land already exist at the outskirts of the town which may in themselves soon constitute an environmental nuisance. Similar sites where laterite has been removed for construction purposes should be adopted and used as solid waste disposal sites. Industrial and recreational wastes, where they are safe, should similarly be disposed. Correct management at the present time will prevent these wastes becoming an environmental hazard in the future. Once the standard is laid down, it will be easy to enforce the rules as new industries develop. The inadequate drainage system in Ilorin has been identi®ed, amongst others (Adedibu, 1986), as a problem resulting from improper solid waste disposal. It is essential that the people should be adequately educated and ready to participate eectively and change their behavioural and attitudinal approach to their living environment. Government eorts may be in the wrong direction: the prevailing economic and political situation in the country notwithstanding, the war against ®lth should be launched and the provisions of the 1984 edict implemented, so as to achieve a better living environment. In the words of Kinako (1979) `large and nauseating refuse dumps do not have to be a permanent characteristic feature of Nigerian urban centres'. 74
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The Environmentalist
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