ASSESSMENT OF THE EXISTING DUMPSITES

Introduction

Background of Study

Wastes can be considered, as those materials no longer required by an individual, institution or industry. Wastes are thus regarded as by-products or end products of the production and consumption process respectively. Solid waste can be defined as: ‘The useless and unwanted products in the solid state derived from the activities of the society and hence discarded off by the society.’ Solid waste results from various sources, such as animal wastes, hazardous wastes, industrial and medical wastes, food wastes, mineral waste, and nonhazardous wastes.

In the late 1990s, it was estimated that each person in the world generated 200kg of solid waste per year (UNCHS, 2001) and this was forecasted to increase with the growth in population. The quality and generation rate of solid wastes in Nigeria have increased at an alarming rate over the years with lack of efficient and modern technology for their management (Babayemi and Dauda, 2009). Solid waste management has remained an intractable environmental sanitation problem in Nigeria. This problem has manifested in the form of piles of indiscriminately disposed heaps of uncovered waste and illegal dumpsites along major roads and at street corners in cities and urban areas. This problem is compounded by the rapid urbanization and population growth which has led to the generation of enormous quantities of solid waste which are often discarded by open dumping. The rate of increase in the quantity of waste generated in relation to the population size can only worsen urban environmental issues and planning as a whole (Babayemi and Dauda, 2009).

Solid wastes are mainly disposed off to dumpsite, because it is the simplest and cheapest method of disposing waste (Barret and Lawler, 1995). Rushbroke (2001) describes open dumping of municipal solid waste (MSW) as a primitive stage of waste disposal, practiced by three fourths of countries and territories round the world. Open dumps are the major causes of environmental degradation and public health concerns in many developing countries including Nigeria. These waste dumps may contain a mixture of general waste and toxic, infectious or radioactive wastes and are susceptible to burning and exposure to scavengers. There are a number of major risks and impacts of the dumpsites on the environment. For instance, air pollution from open burning, due to emission of green house gases such as methane and carbon dioxide; the air emissions and leachates generated as a result of decomposition of waste may contaminate air, surface and groundwater sources; fire hazards and explosions cause public health risks as well.

The emission of greenhouse gases, rats and fly infestation and nuisance effects are among the health and environmentalimpacts of poor solid waste management. In addition, scattering of wastes by wind and scavenging by birds, animals and waste pickers creates aesthetic nuisance. Malodour emanating due to the degradation of the waste in the dumpsite has nuisance effect and decreases the economic and social values in the locality. In many dumpsites, the waste is directly exposed due to the absence of daily cover on the dumped waste and this attracts the animal and human scavengers (Kurian et al, 2004).

According to DEAT (2001), the life and dumpsite and landfill can be managed if wastes disposed to dumpsites are minimized through waste recycling and resource recovery and the vision of the Polokwane declaration is to reduce solid wastes landfilled to 50% of current levels by 2012 and to zero by 2022. If resources (both renewable and non renewable) are salvaged, dumpsites air space will be more effectively utilized and pollution and environmental degradation will be reduced.

Statement of Problem

Over the last three decades there has been increasing global concern over the public health impacts attributed to environmental pollution, in particular, the environmental quality and human health risks associated with the waste dumps. World Health Organization estimated that about a quarter of the diseases facing mankind today occur due to prolonged exposure to environmental pollution (UNEP, 2006). Unfortunately there seems to be no clear cut guidelines at the national or state levels on how to deal with these dumpsites in a sustainable manner, particularly in the developing where ironically the burden of environmental pollution seems to be highest. It is suggested that the first task would be to decide on one of three options: if the dumpsite should be closed, remediated or rehabilitated (Kurian et al, 2005)..

To determine whether to rehabilitate and close or remediate, upgrade and operate a dumpsite may require an environmental impact assessments studies (EIAs) including consultation with the interested and affected parties, specifically the adjacent communities. In countries like Nigeria where the number of existing dumpsites (both legal and illegal) are many, economic considerations of the evaluation process must be taken into consideration in recommending a suitable approach or methodology.

Assessing the relative health and environment hazards posed by the dumpsites existing throughout the developing countries could help prioritize, plan and initiate dumpsite rehabilitation (Kurian et al, 2005).

In order to prolong the life of the current dumpsites and landfills in the country and optimally manage the new ones, they need to be redesigned and reconstructed, following the internationally acceptable standards and regulations. Landfills (dumps) in the case study (Ogun State) generally were not subject to the regulations governing modern landfills and were usually sited for convenience such as the presence of a pre existing hole into which wastes could be deposited. This research seeks to assess the suitability of dumpsites location within Abeokuta North and South Local Government area of Ogun state with a view of identifying suitable areas across the state for future landfill projects using site selection criteria.

Research Question

The following questions are intended to be answered by this study

1. Where are the designated dumpsites within Abeokuta North and South Local Government of Ogun State?
2. What are the qualities of the waste in the designated dump site within Abeokuta North and South Local Government of Ogun state

Justification / Rationale of Study

The lack of effective waste management strategy is a potential threat to achieving sustainable development in Nigeria. Studies that would bring about strategies to manage these wastes are urgently needed. Hence, the purpose of this study is to provide a scientific assessment of an existing dumpsite in Ogun state. Landfills offer promising potentials for both energy as well as raw material recovery. In addition, they offer easiest and cheapest way of waste disposal. While the predominant reasons for dumpsite deconstruction and reclamation in the past have been environmental pollution and degradation. At present and in the future, the motivation should be their proper location through constraint mapping, using site selection criteria. If properly located and constructed, dump sites has many environmental besides economic benefits. Revenues from recyclable and re-useable materials (e.g. ferrous metals, aluminum, plastic and glass) provide people with sustained

Income generation; reclaimed soil used as cover material or sold as construction fill or sold for other uses. The recovery of metals from old dumpsites seems also reasonable in respect to the strongly increasing prices of raw materials (EUWID, 2008)

Significance of Study

Internationally, landfills have significant waste management potentials. Proper site selection for dumpsites has potentials for increasing dumpsite life span protecting the environment from further pollution from indiscriminate waste dumping and enhancing conversation of natural resources and virgin materials so as to eradicate poverty through income generation. However, these benefits are still not fully taken into advantage in Nigeria due to poor site location for the dumpsites/landfills. This is partly because the major issues that determine the success of dumpsites selection and construction have not been earnestly addressed. That is environmental impact assessment and audit of each dump site has not been given the much attention it deserved. It will also provide necessary information for appropriate/suitable site which in the long run increase the life span of these sites and reduce the necessity for reclamation in the future.

At present there are hardly any documented experiences with the use of risk based approaches for the management of dumpsites in Nigeria. The need for a risk based tool that is suited to the peculiarities of a developing country and that has been tested and proven to be useful, scientifically sound and easy to apply is therefore urgently required, given the number o f waste dumps in Nigeria and the march towards the achievement of vision 20-20-20 (the vision of the Nigerian state to become one of the twentieth largest economies in the world by the year 2020). This study will therefore provide basis for action and suggest modification for better result.

Objectives of Study

Broad Objective

The broad objective of this study is to assess the existing dumpsites in Abeokuta North and South Local Government of Ogun State.

Specific Objectives

The specific objectives are to:

Identify and list all the designated dumpsites in Abeokuta North and South Local Government of Ogun state
Carry out Physical and Chemical characterization of waste at dumpsites in Abeokuta North and South Local Government of Ogun state.