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| − | [[Image:DCOM_Volume_I_2020-03-11.png|540px|link=Preface]] | + | [[Image:DCOM_Volume_I_Book_PrintReady.png|540px|link=Preface]] |
| − | <h4>Volume I: Design of Water Supply Projects </h4> [[Preface|Readmore...]]or Download [[:File:DCOM_Volume_I_2020-03-10.pdf| Volume I PDF]] | + | <h4>Volume I: Design of Water Supply Projects </h4> [[Preface|Readmore...]]or Download [[:File:DCOM_VOLUME_I_Book_PrintReady.pdf| Volume I PDF]] |
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| | TABLE OF CONTENTS | | TABLE OF CONTENTS |
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| − | ! Header text !! Header text !! Header text | + | ! # !! Title !! Page |
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| − | | Example || [[CHAPTER ONE: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 1 || [[Preface VOL.1|Preface]] || i |
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| − | | Example || [[CHAPTER TWO: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 2 || [[Acknowledgements VOL.1|Acknowledgements]] || ii |
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| − | | Example || [[CHAPTER THREE: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 3 || [[List_of_Special_Committee_Members VOL.1|List of Special Committee Members VOL.1]] || iii |
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| − | | Example || [[CHAPTER FOUR: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 4 || [[List_of_Abbreviations I|List of Abbreviations I]] || iv |
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| − | | Example || [[CHAPTER FIVE: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 5 || [[Chapter_One:Introduction VOL1|Chapter One: Introduction]] || 1 |
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| − | | Example || [[CHAPTER SIX: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 6 || [[Chapter Two: Project Planning|Chapter Two: Project Planning]] || 17 |
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| − | | Example || [[CHAPTER SEVEN: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 7 || [[Chapter Three: Water Sources Analysis|Chapter Three: Water Sources Analysis]] || 35 |
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| − | | Example || [[CHAPTER EIGHT: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 8 || [[Chapter Four: Water Demand Assessment|Chapter Four: Water Demand Assessment]] || 56 |
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| − | | Example || [[CHAPTER NINE: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 9 || [[Chapter Five: Pipelines Design|Chapter Five: Pipelines Design]] || 76 |
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| − | | Example || [[CHAPTER TEN: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 10 || [[Chapter Six: Pumping Systems|Chapter Six: Pumping Systems]] || 91 |
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| − | | Example || [[CHAPTER ELEVEN: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 11 || [[Chapter Seven: Water Treatment|Chapter Seven: Water Treatment]] || 96 |
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| − | | Example || [[CHAPTER TWELVE: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 12 || [[Chapter Eight: Treatment of Waters With Special Contaminants|Chapter Eight: Treatment of Waters With Special Contaminants]] || 148 |
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| − | | Example || [[CHAPTER THIRTEEN: INTRODUCTION|CHAPTER ONE: INTRODUCTION]] || Example | + | | 13 || [[Chapter Nine: Design of Water Structures|Chapter Nine: Design of Water Structures]] || 159 |
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| − | | Example || [[APENDICES: APPENDICES]] || Example | + | | 14 || [[Chapter Ten: Application Software|Chapter Ten: Application Software]] || 203 |
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| + | | 15 || [[Chapter Eleven: Metering|Chapter Eleven: Metering]] || 208 |
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| − | | i || LIST OF SPECIAL COMMITTEE MEMBERS || V | + | | 16 || [[Chapter Twelve: Design Standards and Specifications|Chapter Twelve: Design Standards and Specifications]] || 217 |
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| − | | 1|| CHAPTER ONE: INTRODUCTION || 1 | + | | 17 || [[Chapter Thirteen: Role of Stakeholders in Design of Water Supply Projects|Chapter Thirteen: Role of Stakeholders in Design of Water Supply Projects]] || 228 |
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| − | | 1.1|| Global Considerations on Water Supply and Sanitation || 1 | + | | 18 || Apendices: Appendices |
| − | |- | + | * [[DCOM Volume I Appendix A|Appendix A: Climate Change and Resilience to Climate Change ]] |
| − | | 1.1.1 || Global Considerations on Water Supply and Sanitation || 1
| + | * [[DCOM Volume I Appendix B|Appendix B: Minimum Water Flow Requirement for Fire Fighting ]] |
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| + | * [[DCOM Volume I Appendix C|Appendix C: Example: Estimating The Capacity Of Tank ]] |
| − | | 1.1.2 || Climate Change and Resilience to Climate Change || 2
| + | * [[DCOM Volume I Appendix D|Appendix D: Structural Design of Concrete ]] |
| − | |- | + | * [[DCOM Volume I Appendix E|Appendix E: Supply Pumping Systems ]] |
| − | | 1.1.3 || Public-Private Partnership in Water Supply and Sanitation Projects in Developing Countries || 3
| + | * [[DCOM Volume I Appendix F|Appendix F: Source of Pumping Power ]] |
| − | |- | + | * [[DCOM Volume I Appendix G|Appendix G: Additional Details of Various Unit Oprations ]] |
| − | | 1.1.4 || International Water Law || 4 | + | * [[DCOM Volume I Appendix H|Appendix H: Methods for Disinfecting Water ]] |
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| + | * [[DCOM Volume I Appendix I|Appendix I: Measurements of Water Hardness ]] |
| − | | 1.2 || Development Agenda and Water and Sanitation Sector in Tanzania || 5
| + | * [[DCOM Volume I Appendix J|Appendix J: Basic Statistics Used in Estimation of Design of Flood Events ]] |
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| + | * [[DCOM Volume I Appendix K|Appendix K: Dams Detail Design ]] |
| − | | 1.2.1 || National Water Policy || 7 | + | * [[DCOM Volume I Appendix L|Appendix L: Standard Drawings ]] |
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| + | * [[DCOM Volume I Appendix M|Appendix M: Selected Intake Designs ]] |
| − | | 1.2.2|| Legal and Institutional Framework for Water Supply and Sanitation Services || 8
| + | * [[DCOM Specification|Appendix O: Standard Specifications ]] |
| − | |- | + | || 231 |
| − | | 1.2.3 || Coverage and Access to Water Supply Services || 9 | |
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| − | | 1.2.4|| Policy Environment for Water and Sanitation Services in Tanzania || 9
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| − | | 1.2.5 || Major Stakeholders in Water Supply and Sanitation Projects || 10
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| − | | 1.2.6 || Water Supply and Sanitation Public Private Partnership in Tanzania || 11
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| − | | 1.3 || Rationale for Preparation of the Fourth Edition DCOM Manual || 13
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| − | | 1.4 || About the Fourth Edition of the DCOM Manual || 13
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| − | | 1.5 || Organisation of the 4th edition of the DCOM Manual || 14
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| − | | 1.6 || Purpose of this Volume || 14
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| − | | 1.7 || References || 15
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| − | * CHAPTER TWO 17
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| − | * PROJECT PLANNING 17
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| − | * 2.1 Planning Considerations for Water Supply Projects 17
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| − | * 2.2 Project Planning Steps 18
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| − | * 2.3 Pump Protection 18
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| − | * 2.3.1 Initiation 18
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| − | * 2.3.1.1 Community Assessment Steps 20
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| − | * 2.3.1.2 Methods of conducting community assessment 20
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| − | * 2.3.1.2.1 Comprehensive community assessment 20
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| − | * 2.3.1.2.2 Strategic community assessment 20
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| − | * 2.3.2 Pre-feasibility Study 21
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| − | * 2.3.3 Feasibility Study 21
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| − | * 2.3.3.1 Water Supply Projects Ranking and Technology Selection Criteria 22
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| − | * 2.3.3.1.1 Ranking of Projects 22
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| − | * 2.3.3.1.2 Choice of Technology 23
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| − | * 2.3.4 Preliminary and Detailed Design 23
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| − | * 2.3.4.1 Detailed Engineering Drawings 24
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| − | * 2.3.4.2 Detailed estimates of capital costs 24
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| − | * 2.3.4.3 Detailed estimates of recurrent costs 24
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| − | * 2.3.4.4 Anticipated revenue 25
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| − | * 2.3.4.5 Detailed design report 25
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| − | * 2.3.4.6 Project write-up to be submitted to potential financiers 25
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| − | * 2.3.5 Project Phasing 25
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| − | * 2.3.6 Procurement 26
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| − | * 2.3.6.1 2.2.6.1 Preparation of Tender Documents 26
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| − | * 2.3.6.2 Tendering process 27
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| − | * 2.3.7 Implementation/Construction Stage 27
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| − | * 2.3.7.1 Contract Management 27
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| − | * 2.3.7.2 Contract supervision and administration 27
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| − | * 2.3.8 Operation and Maintenance Stage 28
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| − | * 2.3.9 Performance Monitoring 28
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| − | * 2.4 Consulting the Integrated Water Resources Management and Development (IWRMD) Plans 28
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| − | * 2.4.1 Status of Development and Implementation of IWRMD Plans 29
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| − | * 2.4.2 Components of IWRMD Plans 30
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| − | * 2.5 Consult Guidelines for Preparation of Water Safety Plans - Resilient to Climate Change 30
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| − | * 2.6 Environmental and Social Impact Assessment Compliance 30
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| − | * 2.6.1 Procedures for Conducting ESIA in Tanzania 31
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| − | * 2.6.2 Strategic Environmental and Social Assessment (SESA) Compliance 31
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| − | * 2.7 Potential Impacts of Climate Change on Water Supply Projects 32
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| − | * 2.8 Participation of Community Based Water Supply Organizations (CBWSO) in Various Planning Stages 32
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| − | * 2.9 References 32
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| − | * CHAPTER THREE 35
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| − | * WATER SOURCES ANALYSIS 35
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| − | * 3.1 Availability of Water Resources in Tanzania Mainland 35
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| − | * 3.2 Water Sources Available in Tanzania Mainland 38
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| − | * 3.2.1 Rainwater and fog harvesting 39
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| − | * 3.2.2 Surface Water 39
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| − | * 3.2.2.1 Rivers or streams 39
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| − | * 3.2.2.2 Impoundments 39
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| − | * 3.2.2.3 Springs 39
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| − | * 3.2.2.4 Lakes 39
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| − | * 3.2.2.5 Dams 40
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| − | * 3.2.3 Groundwater 40
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| − | * 3.2.3.1 Infiltration galleries/wells 40
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| − | * 3.2.3.2 Well 40
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| − | * 3.2.3.3 Classification of wells based on the aquifer tapped 41
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| − | * 3.2.3.3.1 Shallow wells 41
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| − | * 3.2.3.3.2 Deep wells 41
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| − | * 3.2.3.3.3 Artesian wells 41
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| − | * 3.3 Quality Suitability of Water Sources for Water Supply Projects 42
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| − | * 3.4 Pilot Testing of Water Sources for Establishment of Appropriate Treatment 42
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| − | * 3.5 General Considerations for Selection of Water Sources 42
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| − | * 3.5.1 Adequacy and reliability 42
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| − | * 3.5.2 Quality of water sources 43
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| − | * 3.5.3 Technical Requirements 43
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| − | * 3.5.4 Cost implications to develop a water source 43
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| − | * 3.5.5 Protection of water sources 43
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| − | * 3.5.6 Legal and management requirements 44
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| − | * 3.5.7 Distance of water supply source 44
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| − | * 3.5.8 Topography of the project area and its surroundings 44
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| − | * 3.5.9 Elevation of a source of water supply 44
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| − | * 3.6 Determination of water source yield 44
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| − | * 3.6.1 Rainwater and fog harvesting 45
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| − | * 3.6.1.1 Rainwater harvesting 45
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| − | * 3.6.1.1.1 Types of rainwater harvesting 45
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| − | * 3.6.1.1.2 Components of rainwater harvesting system 46
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| − | * 3.6.1.1.3 Estimation of the yield 47
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| − | * 3.6.2 Hydrological Analysis of Surface Waters 47
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| − | * 3.7 Other considerations for various water sources 55
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| − | * 3.7.1 Water permits Considerations 55
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| − | * 3.7.2 Conservation of water sources 55
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| − | * 3.8 References 55
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| − | * CHAPTER FOUR 56
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| − | * WATER DEMAND ASSESSMENT 56
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| − | * 4.1 Water Demand Assessment 56
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| − | * 4.2 General Factors Affecting Water Demand Assessment 57
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| − | * 4.3 Determination of Water Demand for Different Uses 58
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| − | * Step 7. Establish Net Water Demand 67
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| − | * Step 9: Establish Operational water consumption 67
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| − | * Step 10: Establish System water losses 68
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| − | * Step 11 Establish Non-Revenue Water 69
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| − | * 4.4 Variations in Water Consumption 70
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| − | * 4.4.1 Definitions 70
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| − | * 4.4.2 Variation in the Rate of Consumption 71
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| − | * 4.4.2.1 Diurnal variation in demand 71
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| − | * 4.4.3 Peak Factors 72
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| − | * 4.4.4 Predicting Demand 74
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| − | * 4.4.5 Design Demand 75
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| − | * 4.5 References 75
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| − | * CHAPTER FIVE 76
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| − | * PIPELINES DESIGN 76
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| − | * 5.1 Design Requirements of pipelines 76
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| − | * 5.2 Types of pipelines 76
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| − | * 5.3 Security considerations for pipelines 76
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| − | * 5.3.1 Methods of water transmission and distribution 76
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| − | * 5.3.2 Gravity flow 77
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| − | * 5.3.3 Pumping with storage 77
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| − | * 5.3.4 Direct pumping to the distribution system 77
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| − | * 5.4 Pipeline Hydraulics Assessment 77
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| − | * 5.4.1 Pressure 77
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| − | * 5.4.2 Determination of Head Losses 77
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| − | * 5.5 Water supply transmission system 79
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| − | * 5.5.1 Determination of Transmission Pipe Size 79
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| − | * 5.5.2 Maximum Pressure 79
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| − | * 5.6 Distribution system 80
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| − | * 5.6.1 Branched System 80
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| − | * 5.6.2 Looped System 81
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| − | * 5.7 Pipe network analysis 82
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| − | * 5.7.1 Network analysis by Conventional method (Hardy Cross) 82
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| − | * 5.7.2 Network Analysis by Computer Software 82
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| − | * 5.7.2.1 EPANET Software 82
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| − | * 5.7.3 Pipeline design criteria 85
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| − | * 5.8 Pipeline materials selection 86
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| − | * 5.8.1 Considerations in Selecting Pipeline Materials 86
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| − | * 5.8.1.1 Flow Characteristics 86
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| − | * 5.8.1.2 Pipe Strength 86
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| − | * 5.8.1.3 Durability 87
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| − | * 5.8.1.4 Type of Soil 87
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| − | * 5.8.1.5 Availability 87
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| − | * 5.8.1.6 Cost of Pipes 87
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| − | * 5.8.2 Types of Pipe Materials Available 87
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| − | * 5.8.2.1 Galvanized Iron (GI) Pipes 87
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| − | * 5.8.2.2 Plastic Pipes 87
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| − | * 5.9 Appurtenances for transmission and distribution mains 88
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| − | * 5.9.1 Valves 89
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| − | * 5.9.1.1 Isolation Valves 89
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| − | * 5.9.1.2 Check Valves 89
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| − | * 5.9.1.3 Float Valves 89
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| − | * 5.9.1.4 Air Release Valves 89
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| − | * 5.9.1.5 Pressure Reducing Valves 89
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| − | * 5.9.1.6 Washout valves 89
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| − | * 5.9.2 Fittings 89
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| − | * 5.10 References 90
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| − | * CHAPTER SIX 91
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| − | * PUMPING SYSTEMS 91
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| − | * 6.1 Introduction 91
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| − | * 6.2 Rationale 91
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| − | * 6.3 Common Types of Pumps used in water supply 91
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| − | * 6.4 Pumping System Setup 91
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| − | * 6.5 Source of Pumping Power 92
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| − | * 6.6 Pumping system design pump selection 92
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| − | * 6.7 Pump Protection 95
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| − | * 6.8 References 95
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| − | * CHAPTER SEVEN 96
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| − | * WATER TREATMENT 96
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| − | * 7.1 Introduction 96
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| − | * 7.1.1 Classification of the qualities of water sources found in Tanzania according to the complexity of its treatment 96
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| − | * 7.1.2 Classification of Unit Operations to achieve water treatment levels 99
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| − | * 7.2 Recommended overall design approach for treatment plant components 99
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| − | * 7.3 Documents and websites consulted and those which are hyper-linked to the DCOM Manual 100
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| − | * 7.4 Water treatment design considerations 100
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| − | * 7.5 Water treatment levels and units 101
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| − | * 7.5.1 Pre-treatment 101
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| − | * 7.5.1.1 Scum and Floating Materials Skimmer 101
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| − | * 7.5.1.2 Screening or straining 101
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| − | * 7.5.1.3 Grit Removal 103
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| − | * 7.5.1.3.1 Design criteria 103
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| − | * 7.5.1.4 Sand Traps 105
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| − | * 7.5.1.5 Pre-chlorination 107
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| − | * 7.5.1.6 Water pre-conditioning (pH adjustment) 108
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| − | * 7.5.2 Primary Treatment 108
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| − | * 7.5.2.1 Sedimentation 108
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| − | * 7.5.2.2 Primary Filtration 114
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| − | * 7.5.2.2.1 Slow Sand Filtration 114
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| − | * 7.5.2.2.2 Rapid Gravity Sand Filtration 117
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| − | * 7.5.2.2.3 Comparison between Slow Sand Filters and Rapid Sand Filters 118
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| − | * 7.5.2.2.4 Other Types of Filters 119
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| − | * 7.5.2.3 Floatation 124
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| − | * 7.5.2.3.1 Dissolved-Air Floatation 124
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| − | * 7.5.2.3.2 Electrolytic Floatation 125
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| − | * 7.5.2.3.3 Dispersed-Air Floatation 125
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| − | * 7.5.2.4 Aeration 125
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| − | * 7.5.2.4.1 Falling Water Aerators 126
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| − | * 7.5.2.4.2 Spray Aerators 127
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| − | * 7.5.3 Secondary Treatment 130
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| − | * 7.5.3.1 Clarification 130
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| − | * 7.5.3.2 Coagulation 130
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| − | * 7.5.3.3 Flocculation 131
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| − | * 7.5.3.4 Filtration 131
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| − | * 7.5.4 Tertiary Treatment 132
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| − | * 7.5.4.1 Disinfection 132
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| − | * 7.5.4.1.1 Disinfection Methods 132
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| − | * 7.5.4.1.2 Chlorinators 132
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| − | * 7.5.4.1.3 Design considerations for chlorinators 133
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| − | * 7.5.4.2 Ozonation 133
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| − | * 7.5.4.3 Water softening 134
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| − | * 7.5.4.3.1 Methods of Softening 135
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| − | * 7.5.4.4 Defluoridation of Water 139
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| − | * 7.5.4.4.1 Fluorides 139
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| − | * 7.5.4.4.2 Defluoridation 139
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| − | * 7.5.4.5 Water Conditioning 141
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| − | * 7.5.5 Managemen
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