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An appropriate wastewater treatment system in developing countries: Thailand as a case study

Dissertation
Author: Wichitra Singhirunnusorn
Abstract:
Using appropriate technology suitable for local conditions is a key requirement to overcome operational failures of wastewater facilities in many developing countries. The term "appropriate" thus conveys the notions of feasibility and pragmatism for a specific circumstance. In sustainable terms, appropriateness also signifies the logic for meeting people's needs in the best possible way with two preconditions--the availability of local resources and the limitation of local conditions. Suitable option is, therefore, not only a system providing the best performance at least cost, but is also sustainable in terms of meeting local needs--socio-cultural acceptability, technological and institutional feasibility, economical affordability, and environmental acceptability. This study aims to devise a comprehensive approach for selecting appropriate wastewater treatment systems in Thailand. Apart from the technical aspects of the treatment systems, the study integrated social, economic, and environmental aspects to develop a set of criteria and indicators (C&I) useful for evaluating appropriate systems. The study takes the C&I approach to develop the selection framework appropriate to the context of Thailand. The well-constructed set of C&I can be used to express what appropriate wastewater treatment systems mean for a specific location and can be incorporated within the selection process of wastewater treatment system for the community. A set of proposed criteria and indicators is used to assess the operating municipal wastewater treatment plants in Thailand. The study provides a case study which is a systematic analysis of four wastewater treatment alternatives for Rom Klao and Fuen Nakorn Rom Klao communities. Assessment results obtained from the previous processes are used to develop a multi-criteria module for a decision support system. The study uses multi-criteria decision analysis (MCDA) techniques developed in the first part of the dissertation for comparing and rank ordering wastewater treatment technology alternatives against the identified technical, socio-economic, and environmental objectives. The proposed wastewater treatment options obtained from the MDCA are analyzed with the local needs, availability of resource, and constraints before the most locally appropriate system is selected.

TABLE OF CONTENTS Page TABLE OF CONTEXTS iv LIST OF FIGURES iv LIST OF TABLES iv ACKNOWLEDGMENTS iv VITA iv ABSTRACT iv CHAPTER 1 INTRODUCTION 1 1.1 STATEMENT OF PROBLEMS 1 1.2 STATEMENT OF RESEARCH QUESTIONS 2 1.3 RESEARCH OBJECTIVES 3 1.4 RESEARCH APPROACH AND CONCEPTUAL FRAMEWORK 4 1.4.1 Sustainable Infrastructure Development 4 1.4.2 Research Framework 6 1.5 DISSERTATION ORGANIZATION 8 CHAPTER 2 LITERATURE REVIEW 10 2.1 INTRODUCTION 10 2.2 WASTEWATER TREATMENT TECHNOLOGY OPTIONS AND MANAGAEMENT APPROACHES 11 2.2.1 Existing Wastewater Treatment Technologies 11 2.2.1.1 Classification by Locational Dimensions 11 2.2.1.2 Classification by Dimensions of Treatment Techniques 19 2.2.2 Wastewater Management Approaches in Developing Countries 23 2.2.2.1 Centralized Wastewater Management Approach 24 2.2.2.2 Decentralized and Sustainable Wastewater Management Approach 25 2.2.3 Development of Urban Wastewater Treatment Infrastructure 28 2.2.3.1 Urban Contexts of Developing and Developed Countries 28 2.2.3.2 Wastewater Management Problems in Developing Countries 30 iv

2.3 SELECTION CRITERIA FOR APPROPRIATE WASTEWATER TREATMENT SYSTEMS 33 2.3.1 Different Aspects of Local Conditions and Resource Availabilities 34 2.3.1.1 Social Economic Factors 34 2.3.1.2 Physical Factors 37 2.3.1.3 Institutional and Political Factors 39 2.3.2 Concept and Scope of an Appropriate Wastewater Treatment System 40 2.3.2.1 Technical Aspects 42 2.3.2.2 Socio-Economic Aspects 44 2.3.2.3 Environmental Aspects 45 2.4 APPROACHES AND METHODS FOR TECHNOLOGY SELECTION 46 2.4.1 Conventional Optimization Approaches 47 2.4.1.1 Single-and Multi-Objective Approaches 49 2.4.2 Technology Selection Approaches for Developing Countries 55 2.4.2.1 Non-Mathematical and Simple Approaches 55 2.4.2.2 Analytical Hierarchy Process (AHP) 57 2.4.2.3 Intelligent Tools and Decision Support System 58 2.4.3 Multi-Criteria Decision Analysis: A Framework for Selection of Appropriate Wastewater Treatment Technologies 60 2.4.3.1 Basic Concepts and Decision with Multiple Criteria 61 2.4.3.2 Multi-Criteria Decision Methods and Tools 62 2.4.3.3 Multi-Attribute Utility/Value Theory (MAUT/MAVT) 68 2.4.3.4 Software System 73 CHAPTER 3 METHODOLOGY 75 3.1 DEFINING RESEARCH VARIABLES 75 3.2 DATA COLLECTION 78 3.3 SAMPLING CRITERIA 80 v

CHAPTER 4 RESULTS AND DISCUSSION 82 4.1 DEVELOPMENT OF CRITERIA AND INDICATORS FOR SELECTING APPROPRIATE WASTEWATER TREATMENT SYSTEMS IN THAILAND 82 4.1.1 Approach to Developing Selection Criteria 82 4.1.2 Criteria and Indicator Assessment 85 4.1.3 Data Assembly and Assessment 86 4.1.3.1 Data Collection: Expert Survey 86 4.1.3.2 Data Analysis 87 4.1.4 Results and Discussion 89 4.1.5 Selection of Final Criteria and Indicators 96 4.2 WASTEWATER TREATMENT ALTERNATIVES 99 4.2.1 The State of Wastewater Treatment in Thailand 99 4.2.2 Overview of Identified Wastewater Treatment Alternatives 101 4.3 CALCULATION OF INDICATORS FOR APPROPRIATE WASTEWATER TREATMENT SYSTEMS I l l 4.3.1 Technical Aspects I l l 4.3.1.1 System Reliability (PI) 113 4.3.1.2 Simplicity (P2) 117 4.3.1.3 Efficiency (P3) 122 4.3.2 Socio-Economic Aspects 124 4.3.2.1 Land Requirement (P4) 124 4.3.2.2 Affordability (P5) 129 4.3.2.3 Estimate of Economic Indictors 136 4.3.2.4 Social (public) Acceptability (P6) 140 4.3.3 Environmental Aspects 142 4.3.3.1 Sustainability (P7) 142 4.4 CASE STUDIES 146 4.4.1 Introduction to Study Area 146 4.4.2 Site Characteristics 148 vi

4.5 MULTI-CRITERIA DECSION ANALYSIS 154 4.5.1 Analyzing the Results 159 4.5.2 Sensitivity Analysis 161 4.6 LOCAL FACTORS INFLUENCING THE SELECTION OF COMMUNITY SYSTEM 166 4.6.1 Technical Factors 166 4.6.2 Amount of Land Requirement 167 4.6.3 Affordability 168 4.6.4 Acceptability of Wastewater Treatment Service Charge 170 CHAPTER 5 CONCLUSSIONS 172 5.1 FINDINGS OF THE STUDY 172 5.2 SUGGESTIONS AND FUTURE STUDY 176 APPENDIX A: DATA AND STATISTICS 180 APPENDIX B: LIST OF INDICATORS 200 APPENDIX C: EXAMPLE OF QUESTIONNAIRE: EXPERT SURVEY 203 APPENDIX D: SENSITITY ANALYSIS 209 REFERENCES 211 vn

LIST OF FIGURES Page Figure 1.1 Research Framework 6 Figure 2.1 Important Aspects in the Selection of Wastewater Treatment Systems 34 Figure 2.2 Conceptual Variables Determining the Selection of Appropriate Wastewater Treatment for Developing Countries 42 Figure 3.1 Hypothetical Framework of the Relevant Parameters and Their Interrelation ship 77 Figure 3.2 Overview of the Research Design 79 Figure 4.1 Respondents in the Expert Survey 86 Figure 4.2 Combined Weights of the Principles 90 Figure 4.3 Combined Weights of the Principles from Different Groups of Experts... 91 Figure 4.4 Combined Weights of the Criteria 92 Figure 4.5 Relative Importance of Indicators (Combined Weights) 95 Figure 4.6 Types of Municipal Wastewater Treatment Plants in Thailand 100 Figure 4.7 Size Distributions of Municipal Wastewater Treatment Plants in Thailand 101 Figure 4.8 Typical Activated Sludge Treatment System in Thailand 101 Figure 4.9 Layout of Typical Oxidation Ditch System in Thailand 105 Figure 4.10 Views of Typical Oxidation Ditch System in Thailand 105 Figure 4.11 Layout of Typical Aerated Lagoons in Thailand 107 Figure 4.12 Views of Typical Aerated Lagoons in Thailand 108 Figure 4.13 Layout of Waste Stabilization Ponds in Nakorn Pathom Municipality .110 Figure 4.14 Views of Waste Stabilization Ponds in Thailand 110 Figure 4.15 Summarized Values of Plant Performance Indicators (Long-Term Operation) 115 viii

Figure 4.16 Summarized Values of Plant Performance Indicators (Short-Term Operation) 116 Figure 4.17 Summarized Values of Mechanical Reliability Indicators 117 Figure 4.18 Summarized Values of Simplicity of System Construction, Installation and Startup 119 Figure 4.19 Summarized Values of Simplicity 121 Figure 4.20 Comparative Removal of Water Quality Constituents by Alternative Technologies 123 Figure 4.21 Summarized Values of Efficiency (P3) 124 Figure 4.22 Land Requirements for Different Processes and Design Capacities 126 Figure 4.23 Land Requirements for Identified Wastewater Treatment Alternatives. 127 Figure 4.24 Favorable Land Conditions 129 Figure 4.25 Construction Costs for Different Processes and Design Capacities 132 Figure 4.26 Construction Costs for Identified Wastewater Treatment Alternatives .132 Figure 4.27 Overall Annual O&M Costs for Different Processes and Actual Flows 134 Figure 4.28 Annual O&M Costs for Identified Wastewater Treatment Alternatives 135 Figure 4.29 Economic Indictors for Wastewater Treatment Alternatives 137 Figure 4.30 Economic Indictors for the Case Studies 139 Figure 4.31 Summarized Values of Social Acceptability and Environmental Impact/Perception 141 Figure 4.32 Summarized Values of Limitation factors for the Upgrading & Extension and the Possibility of Resource Recovery 145 Figure 4.33 Location of Study Site 147 Figure 4.34 Settlement Conditions of Case Studies 153 Figure 4.35 Hierarchical of Criteria (Values Tree) 156 ix

Figure 4.36 Example of a Rating-dialog (alternative-indicator matrix) of Criteria 1.1 158 Figure 4.37 Examples Value Function Mao of II.1.1 (A) and 11.1.3 158 Figure 4.38 Overall Values of Alternatives 160 Figure 4.39 Composite Priorities based on Reliability, Simplicity, Efficiency, Social Acceptability and Sustainability 162 Figure 4.40 Composite Priorities based on Land Requirement and Affordability ....163 Figure 4.41 Sensitivity Analyses for Land Requirement and Affordability 164 x

LIST OF TABLES Page Table 2.1 Descriptive Comparison of On-Site Wastewater Treatment Systems 13 Table 2.2 Overview of the Off-Site Wastewater Treatment Systems 15 Table 2.3 Criteria for Sustainable Environmental Protection Concepts 26 Table 2.4 Differences in Urban Contexts of Developing and Developed Countries...29 Table 2.5 Approaches and Methods for Selecting an Appropriate Wastewater Technology 50 Table 2.6 Comparisons of the Multi-Criteria Decision Analysis Methods 64 Table 4.1 Relative Weights of Principles Calculated by Ranking and Rating Method 90 Table 4.2 Central Wastewater Treatment Plants in Thailand 99 Table 4.3 The Main Objectives of Each Criterion 112 Table 4.4 List of Selected Indicators to Evaluate System Reliability 113 Table 4.5 List of Selected Indicators to Evaluate Simplicity 118 Table 4.6 List of Selected Indicators to Evaluate Efficiency 122 Table 4.6 Comparative Removal of Water Quality Constituents by Alternative Technologies 122 Table 4.7 Comparative Removal of Water Quality Constituents by Alternative Technologies 122 Table 4.8 List of Selected Indicators to Evaluate Land Requirement (P4) 125 Table 4.9 Land Requirements for Wastewater Treatment Alternatives in Relation to Design Capacities (m Id) 127 Table 4.10 Buffer Zones for Different Wastewater Treatment Plants 128 Table 4.11 List of Selected Indicators to Evaluate Affordability (P5) 130 Table 4.12 Construction Costs for Wastewater Treatment Alternatives in Relation to Design Capacities (m3/d) 133 xi

Table 4.13 Annual O&M Costs for Wastewater Treatment Alternatives in Relation to Design Capacities (m3/d) 135 Table 4.14 Estimates of Land Requirements, Construction Costs and Annual O&M Costs for Wastewater Treatment Alternatives in the Case Studies 138 Table 4.15 List of Selected Indictors to Evaluate Social (Public) Acceptability (P6) 140 Table 4.16 List of Selected Indicators to Evaluate Sustainability (P7) 142 Table 4.17 The Settlement Conditions of the Study Area 149 Table 4.18 Socio-Economic Conditions in the Study Area 152 Table 4.19 O&M Cost per Household 169 Table 4.20 Ability to Pay for the Wastewater Treatment Service 170 xn

ACKNOWLEDGMENTS I would like to express my gratitude to my advisor, Professor Michael K. Stenstrom, for his support, encouragement, and patience throughout my study at UCLA. His particular support on my scholarship extension was greatly appreciated. I would like to extend my gratitude to other committee members, Asst. Prof. Terri S. Hogue, Assoc. Prof. Jennifer A. Jay, and Assoc. Charles J. Corbett. I would also like to thank Assoc. Prof. Linwood H. Pendleton for his advice during the prospectus examination. My most profound and deeply felt gratitude go to my great supporter, Assoc. Prof. Nopadon Sahachaisaeree who has been there for me since the beginning of my graduate education. I would not have achieved much without you giving me ideas, inspiration, encouragement, listening and discussing, sharing your knowledge, and last but not least your love and sense of humor. I can never thank you enough. I could not be successful as I am today, without you. I wish to express my sincere gratitude to the Ministry of Science, Technology, and Environment for awarding me the Royal Thai Government Scholarship for pursuing Ph.D. in Environmental Engineering at UCLA. I would like to thank also the Office of Civil Service Commission; the Minister-Counselor (education) and staff of the Office of Educational Affair, Royal Thai Embassy in Washington D.C.; Mr. L.B. Tillakaratne at UCLA-the Office of International Students and Scholars; and Maida (department graduate student affairs office) for their administrative support throughout my study. xiii

I would especially like to express my gratitude to Thai experts, wastewater treatment plant operators, members of the Rom Klao and Fuen Nakorn Rom Klao communities, and local authority officials who participated in my surveys. Without whose participation and wisdom, this research would have been impossible. I also thank Thai students from King Mongkut's Institute of Technology Ladkrabang for their help with my questionnaire survey. Nong Pie, it was nice to work with you. Nong Jang, I really appreciated all your help with the mailing surveys. I am very thankful to all my friends for their friendship, encouragement and moral support. I am grateful to my close friends, Tina Sanchez, Julie Ladel, Fatma Cakir, Sunny Li, Sim-lin Lau, Mi-Hyun Park, and Sunhyung Kim for always being there for me and for all joyful moments we shared together. I also would like to extend my thanks to the staff and faculty of the Civil and Environmental Department at UCLA. It has been the most wonderful time of my life to study here and have a chance to know all of you. Finally, I am thankful to my dear family, my parents (Somchai and Ampon), sisters (Jum, Ja, Joy, and Jeab), and brothers (Sun and Jack) for their constant love and support. I am grateful to my cutest nieces and nephews (Mill, Anon, Smile, Smart, and New) who have kept me happy and made me smile throughout the tough time. Pa, I thank you for always believing in me. Mae, thanks for always being proud of me. xiv

VITA January 21, 1973 Born, Singburi, Thailand 1995 B.Sc, Environmental Science Thammasat University Pathumthani, Thailand 1995-1997 Environmental Scientist STS Engineering Consultants Co., Ltd. Bangkok Thailand 1998-2000 Royal Bangkok Sport Graduate Scholarship Awardee King Mongkut's Institute of Technology, Ladkrabang Bangkok, Thailand 2000 M.U.R.P. (Urban and Environmental Planning) King Mongkut's Institute of Technology, Ladkrabang Bangkok, Thailand 2000-2001 Asia-Europe Environmental Technology Center (AEETC), Pathumthani, Thailand 2003 M.S. Civil Engineering University of California, Los Angeles Los Angeles, California 2001-2007 Royal Thai Government Scholarship Awardee University of California, Los Angeles Los Angeles, California PUBLICATIONS AND PRESENTATIONS Singhirunnusorn, W. and Stenstrom, M.K. A critical analysis on economic factors for diverse wastewater treatment processes: Case studies in Thailand. Journal of Environmental Engineering and Management. (Accepted). Singhirunnusorn, W. and Stenstrom, M.K. (2009). Appropriate wastewater treatment systems for developing countries: Criteria and indicator assessment in Thailand. Water Science and Technology. 59(9), 1873-1884. xv

Singhirunnusorn, W. and Sahachaisaree, N. (2009). Integrated approach to urban environmental research in developing countries: A case of solid waste management in Bangkok. In Proceedings of the 10th Asian Urbanization Conference, The University of Hong Kong, Hong Kong SAR China, 16-19 August, 2009. Sahachaisaree, N. and Singhirunnusorn, W. (2009). Negative side-effect of garbage privatization: A case of solid waste policy and management in Bangkok. In Proceedings of the International Perspective on Environmental and Water Resources, Thailand, January 5-7, 2009. Singhirunnusorn, W. and Stenstrom, M.K. (2008). Appropriate wastewater treatment systems for developing countries: The criteria and indicator assessment in Thailand. In Proceedings of the 4X IWA Young Water Professionals Conference, Berkley, California, U.S.A., July 2008. Singhirunnusorn, W. and Sahachaisaree, N. (2008). The impact of solid waste recycling process on the livelihood of urban informal economy: A case study in Bangkok. In Proceedings of Waste-The Social Context Conference, Edmonton, Alberta, Canada, May 11-15,2008 Singhirunnusorn, W., Sahachaisaree, N., and Stenstrom, M.K. (2006). Factors determining community support leading to the success of communal self-managed wastewater treatment system: A case study of low-income communities in Bangkok. In Proceedings of WEFTEC06 Conference, Dallas, Texas, U.S.A., October 2006. xvi

ABSTRACT OF THE DISSERTATION An Appropriate Wastewater Treatment System in Developing Countries: Thailand as a Case Study by Wichitra Singhirunnusorn Doctor of Philosophy in Civil Engineering University of California, Los Angles, 2009 Professor Michael K. Stenstrom, Chair Using appropriate technology suitable for local conditions is a key requirement to overcome operational failures of wastewater facilities in many developing countries. The term "appropriate" thus conveys the notions of feasibility and pragmatism for a specific circumstance. In sustainable terms, appropriateness also signifies the logic for meeting people's needs in the best possible way with two preconditions—the availability of local resources and the limitation of local conditions. Suitable option is, therefore, not only a system providing the best performance at least cost, but is also sustainable in terms of meeting local needs—socio-cultural acceptability, technological and institutional feasibility, economical affordability, and environmental acceptability. This study aims to xvii

devise a comprehensive approach for selecting appropriate wastewater treatment systems in Thailand. Apart from the technical aspects of the treatment systems, the study integrated social, economic, and environmental aspects to develop a set of criteria and indicators (C&I) useful for evaluating appropriate systems. The study takes the C&I approach to develop the selection framework appropriate to the context of Thailand. The well-constructed set of C&I can be used to express what appropriate wastewater treatment systems mean for a specific location and can be incorporated within the selection process of wastewater treatment system for the community. A set of proposed criteria and indicators is used to assess the operating municipal wastewater treatment plants in Thailand. The study provides a case study which is a systematic analysis of four wastewater treatment alternatives for Rom Klao and Fuen Nakorn Rom Klao communities. Assessment results obtained from the previous processes are used to develop a multi- criteria module for a decision support system. The study uses multi-criteria decision analysis (MCDA) techniques developed in the first part of the dissertation for comparing and rank ordering wastewater treatment technology alternatives against the identified technical, socio-economic, and environmental objectives. The proposed wastewater treatment options obtained from the MDCA are analyzed with the local needs, availability of resource, and constraints before the most locally appropriate system is selected. xvm

CHAPTER 1 INTRODUCTION 1.1 STATEMENT OF PROBLEMS Great efforts have been made at both international and local levels to promote and support water supply and sanitation programs in the developing world. Nevertheless, statistical data still shows that approximately two third of the World's population, or 4 billon people, are living without wastewater treatment (Mara, 2001). Most of them live in developing countries. Although the technologies for environmental remediation are available, it has proven difficult to implement them successfully, under the unique local conditions of developing countries. It is the most challenging issue for environmental engineers and decision makers to select and design locally appropriate wastewater treatment systems to meet the specific needs of people in developing countries. Decision makers in these countries choose to apply conventional wastewater treatment techniques widely utilized in developed nations, and ignore the local context and constraints, particularly the affordability, skills, and political will of the relevant authorities. Such advanced wastewater treatment technologies are not only unaffordable, they are also too complicated to operate and maintain (Van Lier and Lettinga, 1999). As a result, a number of treatment plants constructed in developing countries had to be abandoned due to the failure to provide necessary operation and maintenance. 1

In recent years, studies concerning appropriate wastewater treatment technologies and the selection process in developing countries have become important issues, gaining recognition in the fields of environmental engineering and infrastructure planning as illustrated by Reid (1982), Ellis and Tang (1991), Eliman and Kohler (1997), Krovvidy (1998), Rodriguez-Roda et al (2000), Balkema et al. (2001). Many studies in the past centered on the traditional optimization approach by means of mathematical methods, focusing on the solution of systems with the highest performance and least cost (Mishara et al, 1974; Ellis and Tang, 1991). Nonetheless, researchers have begun to consider local factors, such as socio-economic, political, and institutional situations, which have been considered among the prime barriers preventing the success of implementing the selected technology (Ellis and Tang, 1991; Okubo et al, 1994; Loetscher and Keller, 2002). Appropriate wastewater treatment technologies have also been recognized as part of sustainable development strategies in the Third World countries. The suitable option is, therefore, not only a system providing the best performance at least cost, but it should also be sustainable in terms of meeting the local needs—socio-cultural acceptability, technological and institutional feasibility, economical affordability, and environmental acceptability (Mara, 1996; Ujang and Buckley, 2002; Sarmento, 2001). 1.2 STATEMENT OF RESEARCH QUESTIONS The study approaches the problems of wastewater management in developing countries by incorporating the issues of urban development with the aspect of 2

environmental management. The study thus aims to answer the following research questions. 1. What are the factors governing the selection of appropriate technologies in communities located in urban area of developing countries? 2. With factors found in question 1, how can the most appropriate wastewater treatment systems be selected utilizing such factors? In other words, what would be the most appropriate procedure for selection? 3. Using communities in Bangkok as case studies, what are the appropriate wastewater treatment systems applicable for domestic sanitation? 4. How could Bangkok's example be applicable for the needs of sustainable wastewater treatment in communities typical of developing countries? 1.3 RESEARCH OBLECTIVES The study incorporates the social research approach with that of environmental engineering discipline to bring about further insight to the remediation of technology selection failure. The main objectives of the research include the following: 1. Identify and analyze factors governing the selection of appropriate WWT technologies in developing countries; 2. With the findings from previous effort, develop a set of decision criteria and indicators (C&I) useful for the selection process; 3

3. Develop a framework for comparative assessment of alternative wastewater treatment technologies in Thailand by using the set of selected C&I; 4. Develop a decision support tool based on multi-criteria decision analysis (MCDA) methodology for assessing scenarios of Bangkok, Thailand and selecting appropriate wastewater treatment alternatives. The finding from this research was expected to bring about a new line of thought, contributing to the development of decision-making and supporting systems in the field of environmental engineering. With contextual limitation, the results of the study can thus be generalized to the overall population in developing countries in a rather narrow fashion. The generalizations, nevertheless, could be safely made to other developing countries having similar context to Thailand in terms of urban characteristics, socio economic, climatic and living conditions. Following this research, further study in developing countries elsewhere could refine the model to fit their respective local conditions. 1.4 RESEARCH APPROACH AND CONCEPTUAL FRAMEWORK 1.4.1 Sustainable Infrastructure Development The research takes "Sustainable development" as the main approach to develop the basic framework of this study. Sustainable development has recently become one of the most important terms underpinning the wastewater management approach. Although the definition of sustainable development has been originally defined as "meeting the need of 4

the present without compromising the ability of future generation to meet their own needs" (McCarney, 1994 referred to WCED 1987, p.8), a wide range of literature still interprets the term differently. Sustainability of cities concerns the development of systems to meet the needs of city dwellers (development goals) while keeping the minimum environmental costs passed to other people or other ecosystems (sustainable goals) (Hardoy et al, 1995) Sustainability in the urban context especially within developing countries also addresses improved urban dwellers' survival strategy, who struggle to make ends meet in the city (McCarney, 1994 referred Wekwete, 1992). In those cities, the pressing needs, such as access to housing, water, sanitation, and a variety of services, are the priority concerns of the poor. Researchers thus attempted to relate such survival strategy to the consequence of urban environment and infrastructure development (McCarney, 1994). The study of wastewater treatment strategies in developing countries will, therefore, consider poverty issues when trying to fulfill environmental sustainability. The technology to be applied to the urban poor should be sustainable and be chosen by considering the applicable alternatives that meet the needs of the local community, allowing localized operation and maintenance. All stakeholders, particularly from the local communities themselves, should be involved in the informed decision making process to reach the final policy. 5

1.4.2 Research Framework The fundamental assumption of the framework postulates that local factors determine the selection of an appropriate treatment system in the Third World context—the extent of water pollution, socioeconomic factors, physical factors, and institutional and political factors (Figure 1.1). Wastewater Treatment Technology Alternatives Physical Factors The Extent of Water Pollution (Influent) Design Criteria: Technical aspects Socio-economic aspects Environmental aspects Socio-Economic Factors Local Constraints Decision Support Tool Appropriate Wastewater Treatment System Institutional and Political Factors Figure 1.1 Research Framework 6

The problems of wastewater management in developing countries are closely related to a number of local conditions. Apart from the technical or engineering feasibility, the development of wastewater treatment systems needs to be considered hand in hand with the available infrastructure, institutions, human resources, and socio-economic conditions (Mara, 1996; Varis and Somlyody, 1997; Pegram et al., 1999). Household socio-economic status is among the factors determining the household wastewater characteristics. A study of household wastewater production in Brazil showed that amount of wastewater was significantly related to income level. The rate of wastewater production was 74 Liter/capita/day for the lowest income group vis-a-vis 210 Liter/capita/day for the highest income group (Campos and von Sperling, 1996). Income level is also a factor directly contributing to the legal and physical problems of the urban poor (Pegram et al., 1999). The urban poor usually earn insufficient and unstable income, which forces them to live in illegal settlements. The illegality further prevents them from obtaining access to services provided by government, which creates further deterioration of living conditions. A majority of the population in richer areas is able to access to wastewater treatment facilities provided by the city, while services in the poorer areas are virtually nonexistence (Tsagarakis et al., 2001). The political and institutional structures are also constraints complicating the remedy of the existing problems. Examples of such barriers include complications as a result of governmental intervention in wastewater management plans and policies, legislation for controlling and enforcing the policies, institutional arrangements, financing mechanisms, and technical consultation (Pegram, 1999). Local ignorance and negligence in 7

maintaining wastewater systems in communities are likely to be a consequence of governmental irresponsibility and inability to motivate the local civil society (Pegram, 1999). The local conditions—demographic characteristics, community location, density, settlement conditions, local climate, and the availability of sewer systems and on-site treatment—are crucial determinants governing wastewater quality prior to treatment. In this light, the technical feasibility is another important factor in the selection process of an appropriate wastewater treatment system. Systems selected from a pool of existing treatment methods require cautious decision making to derive the most appropriate technology, applicable to the unique social, economic, political, and institutional environment. (See detailed rationale discussion in Chapter 2). 1.5 DISSERTATION ORGANIZATION The dissertation is organized into five chapters. Chapter 1 presents the statement of wastewater treatment problems in developing countries leading to the major research questions and objectives. The approach of this study and the fundamental assumption of research framework are also defined in this introduction chapter. Chapter 2 summarizes an extensive literature review that includes three major sections. The first section focuses on wastewater treatment technologies and management approaches in the context of developing countries. The second section reviews different aspects of local conditions and selection criteria of appropriate wastewater treatment systems. The last section 8

integrates approaches and methods for the technology selection. Chapter 3 specifies methodology for data collection. Results presented in Chapter 4 comprise 6 sections. The first section demonstrates the process of developing criteria and indicators for selecting appropriate wastewater treatment systems in Thailand. Results obtained from the expert survey are used to evaluate and select a final set of criteria and indicators applicable to local situation. Secondly, four wastewater treatment alternatives are identified to be used in the decision analysis process. In the third section, based on the selected criteria and indicators, a plant survey is developed to collect local information and evaluate the operating wastewater treatment systems in Thailand. The fourth section introduces the study area and case study communities. It also establishes a contextual background for the analysis of Rom Klao and Fuen Nakorn Ron Klao settlements. The following section describes the frameworks and principles of multi-criteria decision analysis technique. Findings and results obtained from the model are discussed in order to setup a framework of the decision support model applicable for local authorities and community organizations in the context of Thailand. The last result section elaborates the local socio economic and technical circumstances, and constraints pertaining to the selection of treatment technology in different scenarios in Bangkok. Local factors determining the selection of locally appropriate technology are assessed before making the site-specific recommendation for the case studies. Chapter 5 presents overall conclusions and interesting topics for the future study. 9

CHAPTER 2 LITERATURE REVIEW 2.1 INTRODUCTION In order to establish the theoretical rationale for research, this chapter contains three major sections of review. The first section reviews available treatment technologies for domestic wastewater and management approach in developing countries. The second section discusses methods and approaches for selecting appropriate technologies. The last section elaborates approaches and methods for wastewater technology selection in this study. The first section focuses on wastewater treatment technologies and management approaches in the context of developing countries. This section investigates the key features, strength and weakness of the technologies and highlights the contextual difference between the developed and developing countries, which is the origin of the existing problems. Most policy makers adopt the conventional approaches from the developed countries and applied them in the Third World countries without considering the unique needs of the local communities, the suitability of local conditions, and the availability of resources. The following section reviews the conventional and non- conventional approaches to wastewater selection processes to reach the best solution for the existing sanitation problems and their impact on the urban residents, particularly the low-income communities in the developing countries. The last section touches on several 10

different approaches, such as the optimization approach, the progressive approach, the non-mathematical method, the analytical hierarchy process, and the intelligent tools system. The final part of this section reviews the multi-criteria decision analysis as a basis for developing a model proposition in the study. 2.2 WASTEWATER TREATMENT TECHNOLOGY OPTIONS AND MANAGEMENT APPROACHES 2.2.1 Existing Wastewater Treatment Technologies The following review in this section focuses on the existing domestic wastewater treatment technologies. The system typology is examined in two different dimensions— (1) the locational dimension; namely, the on-site and off-site systems, and (2) the technical dimension; namely, the aerobic, anaerobic and natural processes. The review attempts to investigate the conventional treatment systems which have been commonly used in the developed and developing countries. 2.2.1.1 Classification by Locational Dimensions On-Site System: The on-site systems are mostly utilized separately, each for a single household. Wastewater from each household is channeled to the treatment unit and further to the subsequent wastewater disposal unit (if applicable). In small communities of the developed countries' remote rural areas, the commercially available prefabricated biological plants are popular. The system comprises a set of rather complicated 11

components—a recirculating biological filter, a submerged aerated biological filter, an activated sludge package plants or a sequence batch reactors, and a bio-disc unit (Burkhard et al, 2000). The package functions as a self-contained unit for domestic utilization. Despite its effluent quality, the unit is relatively high in cost and requires professional installation and maintenance. The low-cost on-site technology, in contrast, requires a relatively simple type of construction. There are two types of such technology. The single treatment unit includes a Ventilated Improved Pit (VIP) latrine pit, a pour-flush toilet, a septic tank, a double vault composting, and an aqua privy. The combined system is the integration of a treatment unit and an effluent disposal system such as soak away- or seepage-pit. Factors to be considered during the system selection process are usually the availability of water supply, collection of night soil, disposal facility, site appropriateness, costs, simplicity of construction, and requirements (Kalbermatten et al, 1982) (Table 2.1). A septic tank is one of the low-cost on-site technologies and now the most well-know and commonly used system throughout the world. The system is able to perform the initial treatment well before the wastewater will be transferred and treated by a secondary off-site system. The additional benefit is very low investment cost and labor requirement, both of which are the major constraints in developing countries. A large number of developed countries avoid using some on-site methods due to their low efficiency and high threat to ground and surface waters (Burkhard et al., 2000). In most cases, grey wastewater and all domestic wastewater, with the exception of toilet waste, is not treated by the on-site system. On the other hand, it is a common practice in 12

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Abstract: Using appropriate technology suitable for local conditions is a key requirement to overcome operational failures of wastewater facilities in many developing countries. The term "appropriate" thus conveys the notions of feasibility and pragmatism for a specific circumstance. In sustainable terms, appropriateness also signifies the logic for meeting people's needs in the best possible way with two preconditions--the availability of local resources and the limitation of local conditions. Suitable option is, therefore, not only a system providing the best performance at least cost, but is also sustainable in terms of meeting local needs--socio-cultural acceptability, technological and institutional feasibility, economical affordability, and environmental acceptability. This study aims to devise a comprehensive approach for selecting appropriate wastewater treatment systems in Thailand. Apart from the technical aspects of the treatment systems, the study integrated social, economic, and environmental aspects to develop a set of criteria and indicators (C&I) useful for evaluating appropriate systems. The study takes the C&I approach to develop the selection framework appropriate to the context of Thailand. The well-constructed set of C&I can be used to express what appropriate wastewater treatment systems mean for a specific location and can be incorporated within the selection process of wastewater treatment system for the community. A set of proposed criteria and indicators is used to assess the operating municipal wastewater treatment plants in Thailand. The study provides a case study which is a systematic analysis of four wastewater treatment alternatives for Rom Klao and Fuen Nakorn Rom Klao communities. Assessment results obtained from the previous processes are used to develop a multi-criteria module for a decision support system. The study uses multi-criteria decision analysis (MCDA) techniques developed in the first part of the dissertation for comparing and rank ordering wastewater treatment technology alternatives against the identified technical, socio-economic, and environmental objectives. The proposed wastewater treatment options obtained from the MDCA are analyzed with the local needs, availability of resource, and constraints before the most locally appropriate system is selected.