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Sustainable sewerage infrastructure projects are the keys in achieving sustainable development, as such infrastructure directly impacts on all sustainable development initiatives. Throughout its life cycle, a sewerage system faces a number of challenges and threats to its sustained efficiency, including the impact of ageing, aggressive environmental factors, underfunding, inadequate design, and insufficient operation and maintenance activities. These problems may lead to a rise in the risk of failure, including sewage leakage, overflow, discharge and odour issues. These issues can have significant impacts on the environment, public health and safety, the economy and the service lives of the assets, all of which will affect the sustainability of the sewerage system. Despite its importance and serious consequences, very little research has focused on assessing sustainability at the project level, and no research has assessed a sewerage system throughout its life cycle. In Bahrain, the sewerage system presents a notable variety of challenges related to environmental, economic, social and managerial issues that need to be considered in order to attain a sustainable sewerage system. The original contribution of this research is therefore, to develop a framework for assessing the sustainability of the Kingdom of Bahrain’s sewerage infrastructure projects, thereby ensuring their long-term sustainability. The sustainability-assessment framework will focus on all aspects of sustainability throughout a project’s life cycle, setting it apart from most existing frameworks that focus more on the environmental aspect than on the economic and social aspects. The framework will also support the decision-making process throughout the life cycles of the assets. It will also provide greater transparency for stakeholders. The results of this research are important in addressing shortcomings of the sewerage system in the developing counties by providing a framework for the assessment of the sustainability of sewerage projects for the Kingdom of Bahrain and throughout the Arabian Gulf region. Throughout the research for this thesis, several methodologies were adopted to achieve research objectives, including an extensive review of the relevant literature and of the secondary data that were utilized to clarify the research problem. Then, a conceptual sustainability assessment framework was developed; this framework includes sustainability indicators to determine the sustainability of sewerage infrastructure projects. Furthermore, a mixed-methods approach was used to enhance and verify the framework. First in this approach, experts were consulted to improve the developed framework. This stage of the research resulted in the preliminary sustainability indicators that were used in the next stages of framework development. In the second part of the approach, a pilot study was conducted to improve and enrich the survey. The third part included both quantitative and qualitative data collection through an open-ended survey conducted among experts working in the development of sewerage projects in Bahrain. In the fourth part, the collected data were analysed, resulting in the identification of 43 scored sustainability indicators that led to accomplishing the development of the framework. The developed framework has been applied to three case studies in Bahrain, thus demonstrating how it may be applied successfully. These applications outline the process of selecting indicators, identifying weights and scoring the indicators to determine the sustainability index for the different stages of sewerage projects. The decision-support system is built in line with the project life cycle and its associated six stages: 1) current sewerage system, involves identifying and understanding an existing sewerage network; 2) contextualizing a new project according to the sustainability of the wastewater collection system; 3) planning, designing and constructing, which includes addressing sustainability issues in the project; 4) operation and maintenance, which ensures sustainability performance within the project; 5) periodic assessment, which ensures continual, effective sustainability assessment; 6) rehabilitation/ upgrading, which implements the results of the sustainability assessment in the case of rehabilitation or upgrading. A multi-criteria analysis (MCA) methodology has been adopted in the framework, using sustainability criteria and indicators in assessing sewerage projects and providing a sustainability index. |
