BOOK
How to Design Wastewater Systems for Local Conditions in Developing Countries
David M. Robbins | Grant C. Ligon
(2014)
Additional Information
Book Details
Abstract
This is a practical handbook providing a step-by-step approach to the techniques used for characterizing wastewater sources and investigating sites where collection, treatment and reuse/disposal technologies will be installed. It is intended to help enable local implementation of on-site and decentralized wastewater management system (DWMS)for wide scale use in development settings.
How to Design Wastewater Systems for Local Conditions in Developing Countries helps local service providers and regulatory officials make informed decisions through the use of tools, checklists and case studies. It includes a link to a web based community of on-site and decentralized wastewater professionals, which contains related tools and case studies. This handbook serves as a reference for training classes, certification programs, and higher education programs in civil and sanitary engineering. There is an increasing interest on the part of local government officials and private sector service providers to implement wastewater treatment systems to solve sanitation problems. The model presented in this handbook promotes activities that first generate data related to source and site conditions that represent critical inputs, and then applies this information to the technology selection process. Matching the most appropriate technologies to the specific needs of the wastewater project is the key that leads to long term sustainability.
How to Design Wastewater Systems for Local Conditions in Developing Countries is an invaluable resource for public sector decision makers and private sector service providers in developing countries. It is also a useful text for students at engineering colleges in developing countries interested in taking a class that teaches the methods of decentralized wastewater management system (DWMS) development.
Table of Contents
| Section Title | Page | Action | Price |
|---|---|---|---|
| Cover | Cover | ||
| Contents | v | ||
| Dedication | ix | ||
| Acknowledgements | xi | ||
| Foreword | xiii | ||
| Quick guide – New project checklist | xv | ||
| Chapter 1: Introduction to decentralized wastewater management systems | 1 | ||
| This chapter will | 1 | ||
| About Figure 1.1 | 2 | ||
| 1.1 BACKGROUND | 2 | ||
| 1.1.1 Combining Technologies to Form Systems | 3 | ||
| 1.1.2 Evolution of the Concept | 3 | ||
| 1.1.2.1 A Note on Scale | 4 | ||
| 1.2 THE PURPOSE OF THIS MANUAL | 5 | ||
| 1.3 THE AUDIENCE FOR THIS MANUAL | 5 | ||
| 1.4 THE DWMS DEVELOPMENT MODEL | 6 | ||
| 1.5 HOW TO USE PRINT AND WEB VERSIONS OF THIS MANUAL | 7 | ||
| 1.6 DEFINITIONS AND TERMS | 8 | ||
| 1.7 GUIDING CASE STUDY | 10 | ||
| REFERENCES | 10 | ||
| Chapter 2: Characterizing the source | 11 | ||
| This chapter will | 11 | ||
| About Figure 2.1 | 12 | ||
| 2.1 INTRODUCTION | 12 | ||
| 2.2 WASTEWATER COMPOSITION | 13 | ||
| 2.2.1 Blackwater and Graywater | 13 | ||
| 2.3 WASTEWATER SOURCE CATEGORIES | 14 | ||
| 2.3.1 Residential Housing | 15 | ||
| 2.3.2 Public Markets | 15 | ||
| 2.3.3 Hospitals and Health Care Facilities | 17 | ||
| 2.3.4 Slaughterhouses | 17 | ||
| 2.3.5 Hotels, Resorts, and Restaurants | 17 | ||
| 2.3.6 Office, Daily use, and Less Regular-use Buildings | 18 | ||
| 2.3.7 Schools | 18 | ||
| 2.3.8 Other Commercial Facilities | 18 | ||
| 2.3.9 Community Wastewater Systems | 18 | ||
| 2.4 DETERMINING THE DESIGN FLOW | 19 | ||
| 2.4.1 Measuring Flow | 20 | ||
| 2.4.1.1 The Wastewater Conversion Factor | 21 | ||
| 2.4.2 Gathering and Applying Data from Similar Projects | 21 | ||
| 2.4.3 Using Standard Wastewater Generation Value Tables | 21 | ||
| 2.5 ASSESSING WASTEWATER STRENGTH AND ORGANIC CONCENTRATION | 22 | ||
| 2.6 QUANTIFYING FLOW VARIABILITY | 24 | ||
| 2.6.1 Flow Equalization | 24 | ||
| 2.7 NUTRIENTS IN WASTEWATER | 25 | ||
| 2.7.1 Nitrogen | 25 | ||
| 2.7.2 Phosphorus | 25 | ||
| 2.8 OTHER WASTEWATER POLLUTANTS | 26 | ||
| 2.8.1 Fats, Oils, and Grease | 27 | ||
| 2.8.2 Lint | 27 | ||
| 2.8.3 Trash | 27 | ||
| 2.9 PHYSICAL AND CHEMICAL CONSIDERATIONS | 27 | ||
| 2.9.1 Temperature | 27 | ||
| 2.9.2 The pH Level | 27 | ||
| 2.9.3 Problematic Chemical Constituents in Wastewater | 28 | ||
| 2.10 MICROBIOLOGICAL CONSIDERATIONS | 28 | ||
| 2.11 SAMPLING AND ANALYSIS | 30 | ||
| 2.11.1 Preparing a Sampling Plan | 30 | ||
| 2.11.2 Collecting Representative Samples | 30 | ||
| 2.11.3 Proper Handling and Preservation of Field Samples | 31 | ||
| 2.11.4 Chain of Custody and Sample Identification Procedures | 31 | ||
| 2.11.5 Quality Assurance/Quality Control | 33 | ||
| 2.11.5.1 QA/QC in the Field | 33 | ||
| 2.11.5.2 QA/QC in the Laboratory | 33 | ||
| 2.12 REVIEWING FINDINGS | 33 | ||
| REFERENCES | 35 | ||
| Chapter 3: Evaluating the site | 37 | ||
| This chapter will | 37 | ||
| About Figure 3.1 | 38 | ||
| 3.1 INTRODUCTION | 38 | ||
| 3.2 CREATING AND USING A SITE PLAN SKETCH | 39 | ||
| 3.2.1 Step-by-step Procedure | 40 | ||
| 3.2.2 Estimating the Amount of Land Available | 41 | ||
| 3.2.3 Identifying site Features | 42 | ||
| 3.3 SOILS EVALUATION | 43 | ||
| 3.3.1 Tasks Involved in Soils Evaluation | 43 | ||
| 3.3.2 Excavating Test Holes and Soil Borings | 43 | ||
| 3.3.3 Identifying and Evaluating Soils Horizons | 44 | ||
| 3.3.3.1 Soil Depth and Thickness | 45 | ||
| 3.3.3.2 Soil Texture | 45 | ||
| 3.3.3.3 Evaluating Soil Structure | 47 | ||
| 3.3.3.4 Soil Consistence | 47 | ||
| 3.3.4 Identifying the Water Table and Other Limiting Conditions | 48 | ||
| 3.3.4.1 Depth to Limiting Conditions | 49 | ||
| 3.3.5 Evaluating Slope and Topography | 49 | ||
| 3.3.5.1 Assessing Slope and its Impact on DWMS | 49 | ||
| 3.3.5.2 Topography’s Relationship with Slope | 49 | ||
| 3.3.5.3 Landscape Position and Slope Description | 50 | ||
| 3.3.6 Determining Long Term Acceptance Rate and Identifying Other Soil-based Concerns | 51 | ||
| 3.4 DETERMINING IF SURFACE WATERS ARE LIMITING CONDITIONS | 52 | ||
| 3.5 DETERMINING HOW LAND USE OF SURROUNDING PARCELS AFFECTS DWMS SELECTION | 52 | ||
| 3.6 IDENTIFYING UTILITIES, PRE-EXISTING DWMS, AND RELATED CONFLICTS | 53 | ||
| 3.6.1 Electrical Utilities | 54 | ||
| 3.6.2 Water Availability for System Operation and Maintenance | 54 | ||
| 3.6.3 Existing DWMS Components | 54 | ||
| 3.6.3.1 Accessing Existing Septic Tanks | 55 | ||
| 3.6.3.2 Leak Tests – a Step-by-step Procedure | 55 | ||
| 3.6.3.3 Removing or Abandoning Existing Septic Tanks | 56 | ||
| 3.6.3.3.1 Removing Existing Septic Tanks | 56 | ||
| 3.6.3.3.2 Abandoning Septic Tanks in Place | 57 | ||
| 3.7 EVALUATING ACCESSIBILITY ISSUES FOR DWMS | 57 | ||
| 3.7.1 Assessing Site Accessibility | 57 | ||
| 3.8 BENEFITTING FROM WASTEWATER RESIDUALS | 58 | ||
| 3.9 ASSESSING REGULATORY ASPECTS OF SITE EVALUATION | 59 | ||
| 3.10 REVIEWING FINDINGS | 60 | ||
| REFERENCES | 60 | ||
| Chapter 4: DWMS technologies | 61 | ||
| This chapter will | 61 | ||
| About Figure 4.1 | 62 | ||
| 4.1 DWMS COMPONENT CATEGORIES | 62 | ||
| 4.2 TYPICAL DWMS COMPONENT CATEGORIES | 63 | ||
| 4.3 USER INTERFACE AND PRETREATMENT | 63 | ||
| 4.3.1 User Interface | 63 | ||
| 4.3.1.1 EcoSan Toilets | 63 | ||
| 4.3.1.2 Other Innovative Systems | 64 | ||
| 4.3.2 Pretreatment | 64 | ||
| 4.3.2.1 Grease Traps for Food Service | 65 | ||
| 4.3.2.2 Lint Traps for Commercial Laundries | 66 | ||
| 4.3.2.3 Trash Traps for Public Markets | 66 | ||
| 4.4 CONVEYANCE | 68 | ||
| 4.4.1 Building and Gravity Sewers | 68 | ||
| 4.4.2 Simplified Sewers | 70 | ||
| 4.4.3 Solids-free Sewers | 71 | ||
| 4.4.4 Pressure Sewers | 71 | ||
| 4.4.4.1 STEP Sewer System Components | 72 | ||
| 4.4.4.1.1 Screened Pump Vault | 72 | ||
| 4.4.4.1.2 Pumps | 73 | ||
| 4.4.4.1.3 Electronics | 73 | ||
| 4.4.4.1.3.1 Float switches | 73 | ||
| 4.4.4.1.3.2 High water alarm | 74 | ||
| 4.4.4.1.3.3 Junction boxes | 75 | ||
| 4.4.4.1.3.4 Control panel and accessories | 75 | ||
| 4.4.4.1.3.5 Potential tank for flow equalization: technical considerations | 75 | ||
| 4.5 PRIMARY TREATMENT | 76 | ||
| 4.5.1 Septic Tanks | 76 | ||
| 4.5.2 Anaerobic Baffled Reactors | 77 | ||
| 4.5.2.1 Design Strategy for Septic Tanks and ABRs | 78 | ||
| 4.5.3 Anaerobic Digesters | 78 | ||
| 4.5.4 Other Primary Treatment Options | 80 | ||
| 4.6 SECONDARY TREATMENT | 81 | ||
| 4.6.1 Soils-based Dispersal Systems | 81 | ||
| 4.6.1.1 Leach Trenches | 82 | ||
| 4.6.1.1.1 Design Strategy for Leach Trenches | 83 | ||
| 4.6.2 Constructed Wetlands | 86 | ||
| 4.6.2.1 Design Strategy for Horizontal Subsurface Flow Constructed Wetlands | 88 | ||
| 4.6.3 Waste Stabilization Ponds | 90 | ||
| 4.6.3.1 Anaerobic Ponds | 90 | ||
| 4.6.3.2 Facultative Ponds | 91 | ||
| 4.6.3.3 Aerobic Ponds | 92 | ||
| 4.6.3.3.1 Design Strategy | 92 | ||
| 4.6.3.4 Aerated Ponds | 94 | ||
| 4.6.4 Media Filters | 95 | ||
| 4.6.5 Aerobic Systems | 97 | ||
| 4.7 TERTIARY TREATMENT | 99 | ||
| 4.7.1 Tertiary Filtration | 99 | ||
| 4.7.2 Disinfection | 99 | ||
| 4.8 END OF THE CYCLE -SAFE DISCHARGE OR REUSE | 101 | ||
| 4.9 DETERMINING THE LEVEL OF REQUIRED TREATMENT | 101 | ||
| 4.9.1 Meeting Discharge and Reuse Standards | 102 | ||
| REFERENCES | 104 | ||
| Chapter 5: Selecting wastewater technologies | 107 | ||
| This chapter will | 107 | ||
| About Figure 5.1 | 108 | ||
| 5.1 INTERPRETING THE DATA COLLECTED FROM THE SOURCE AND SITE | 108 | ||
| 5.1.1 Flow to Land Availability Ratio Concept | 108 | ||
| 5.2 TECHNOLOGY SELECTION STRATEGIES | 111 | ||
| 5.2.1 Additional Considerations for Technology Selection | 117 | ||
| 5.3 CONCLUSION AND LOOKING FORWARD | 117 | ||
| REFERENCE | 118 | ||
| Appendices Practical application of soils evaluation data | 119 | ||
| Appendix I: More on soils evaluation | 121 | ||
| A1.1 OVERVIEW OF THE SOILS EVALUATION PROCESS | 121 | ||
| A1.2 SOILS EVALUATION METHODS AND PROCEDURES | 124 | ||
| A1.2.1 Soil Texture and Structure | 124 | ||
| A1.2.2 Soil Consistence | 125 | ||
| A1.2.3 Slope Description and Landscape Position | 126 | ||
| A1.3 STEPS FOR DETERMINING LTAR | 127 | ||
| Appendix II: Example soils evaluation data interpretation and LTAR calculation | 129 | ||
| Example Soils Evaluation Procedure | 129 |