BOOK
Engineering and Costs of Dual Water Supply Systems
S. L. Tang | Derek P.T Yue | Damien C. C. Ku
(2007)
Additional Information
Book Details
Abstract
Fresh water is becoming an ever more valuable and scarce resource, and any method or approach that can contribute to the saving of fresh water resources is therefore beneficial. Dual water supply systems are water supply distribution systems employing two sources, consisting of one fresh water system for potable use, and another system of either seawater, untreated raw fresh water, or treated / reclaimed wastewater for toilet flushing purposes.
The purpose of this book is to discuss the engineering and cost aspects of dual water supply systems drawing on the author's experience obtained in Hong Kong, where dual water supply systems have been used for fifty years. The book is suitable for use as a text book or reference book at undergraduate and postgraduate levels. University undergraduate students and postgraduate students in water science, civil engineering, environmental engineering and environmental science or management will be the principal audiences. Practicing engineers, managers and other practitioners in these fields will also find this an invaluable reference source.
Table of Contents
| Section Title | Page | Action | Price |
|---|---|---|---|
| Contents | vi | ||
| 1 Introduction to Dual Water Supply Systems | 1 | ||
| 1.1 What are dual water supply systems? | 1 | ||
| 1.2 Fresh water supply system | 2 | ||
| 1.2.1 The Distribution System | 2 | ||
| 1.2.2 Water Treatment Process | 3 | ||
| 1.3 Seawater supply system | 3 | ||
| 1.4 Summary | 4 | ||
| 1.5 References | 6 | ||
| 2 Problems Associated with Operating a Seawater Distribution System | 8 | ||
| 2.1 Advantages and disadvantages of dual water supply systems with potable water and seawater | 8 | ||
| 2.2 Chlorination problems | 9 | ||
| 2.3 Cross connection problems | 10 | ||
| 2.4 Deposits and biological growth inside pipelines | 10 | ||
| 2.5 Corrosion problems | 10 | ||
| 2.6 Sudden deterioration of seawater quality | 11 | ||
| 2.7 Ecology problems | 11 | ||
| 2.8 Treatment of mixed (salt + fresh) sewage | 12 | ||
| 2.8.1 Sewage Treatment System Used in Hong Kong | 12 | ||
| 2.8.2 Previous Laboratory Scale Research Work for Treating Mixed Sewage | 13 | ||
| 2.8.3 Experience of Treating Mixed Sewage in Tai Po STW in Hong Kong | 14 | ||
| 2.8.4 Sulphate Concentration and Odour Problems | 15 | ||
| 2.9 Summary | 15 | ||
| 2.10 References | 15 | ||
| 3 Cost comparison of dual water supply systems with conventional single (potable) fresh water system | 17 | ||
| 3.1 Capital investments | 18 | ||
| 3.2 Running costs | 18 | ||
| 3.3 Income generated | 20 | ||
| 3.4 Net present value | 20 | ||
| 3.4.1 An example of calculating NPV | 21 | ||
| 3.4.2 A further example of calculating NPV | 22 | ||
| 3.5 Cost comparison of the two systems | 22 | ||
| 3.5.1 Existing dual water supply systems | 23 | ||
| 3.5.2 Imaginary Single Fresh Water Supply System | 25 | ||
| 3.6 References | 27 | ||
| 4 Using reclaimed water in the dual water supply systems | 28 | ||
| 4.1 The need | 28 | ||
| 4.2 Quantity considerations | 30 | ||
| 4.2.1 Quantity Requirement | 30 | ||
| 4.2.2 Supply Sources | 30 | ||
| 4.2.3 Storage and Backup Supply Facilities | 31 | ||
| 4.3 Quality considerations | 32 | ||
| 4.3.1 Quality Requirement | 32 | ||
| 4.3.2 Quality of Source Water | 32 | ||
| 4.3.3 Water Reclamation Treatment Technologies | 33 | ||
| 4.4 Supply system scale options | 36 | ||
| 4.4.1 General | 36 | ||
| 4.4.2 Municipal Scale | 36 | ||
| 4.4.3 District Scale | 37 | ||
| 4.4.4 Building Lot Scale | 37 | ||
| 4.5 References | 38 | ||
| 5 Cost comparison of seawater, raw fresh water and reclaimed water for toilet flushing | 39 | ||
| 5.1 Background information | 39 | ||
| 5.2 Flushing water resources | 42 | ||
| 5.2.1 Seawater | 42 | ||
| 5.2.2 Raw Fresh Water | 42 | ||
| 5.2.3 Reclaimed Water from Local STWs | 44 | ||
| 5.3 Basic cost assumptions and data for cost comparison of using the three flusing water resources | 45 | ||
| 5.3.1 General | 45 | ||
| 5.3.2 Capital Costs and Recurrent Costs of Existing Facilities | 46 | ||
| 5.3.3 Capital Cost of the Extra Flushing Water Supply Pipelines | 46 | ||
| 5.3.4 Quantity of Flushing Water Supply in the Four Districts | 49 | ||
| 5.4 Cost comparison for cases 1–3 | 50 | ||
| 5.4.1 Case 1: The Toilet Flushing System Using Seawater in SD, SK, NNT and NWNT | 50 | ||
| 5.4.2 Case 2: The Toilet Flushing System Using Raw Water in SD, SK, NNT and NWNT | 52 | ||
| 5.4.3 Case 3: The Toilet Flushing System Using Reclaimed Water in SD, SK, NNT and NWNT | 56 | ||
| 5.4.4 Summary of the Cases | 58 | ||
| 5.5 Comparison of three more cases | 61 | ||
| 5.5.1 Summary of Costs for Case 4 | 62 | ||
| 5.5.2 Summary of Costs for Case 5 | 62 | ||
| 5.5.3 Summary of Costs for Case 6 | 63 | ||
| 5.5.4 Summary of cases 4–6 | 63 | ||
| 5.6 References | 64 | ||
| 6 Possibility of using urban runoff as toilet flushing water | 65 | ||
| 6.1 Advantages of using urban runoff for toilet flushing | 65 | ||
| 6.2 Urban runoff collection system | 67 | ||
| 6.2.1 Conveyance System | 67 | ||
| 6.2.2 Storage Facilities | 67 | ||
| 6.2.3 Treatment Processes for Urban Runoff | 68 | ||
| 6.2.4 Distribution System | 68 | ||
| 6.3 Water quality of urban runoff | 68 | ||
| 6.4 Pollutants in urban runoff | 69 | ||
| 6.4.1 Suspended Solids | 69 | ||
| 6.4.2 Nutrients | 70 | ||
| 6.4.3 Faecal Coliform Bacteria | 70 | ||
| 6.4.4 Heavy Metals | 70 | ||
| 6.4.5 Other Pollutants | 71 | ||
| 6.5 Precautionary measures for protecting the runoff quality | 71 | ||
| 6.5.1 Government of a City | 71 | ||
| 6.5.2 Developers | 71 | ||
| 6.5.3 House Owners | 72 | ||
| 6.5.4 Vehicle Drivers | 72 | ||
| 6.5.5 Construction Sites | 72 | ||
| 6.6 Case studies on urban runoff collection | 72 | ||
| 6.6.1 Case Study in Singapore | 72 | ||
| 6.6.2 Case Study in USA (Santa Monica) | 76 | ||
| 6.6.3 Case Study in Germany (Potsdamer Platz) | 80 | ||
| 6.7 References | 82 | ||
| 7 Concluding remarks | 84 | ||
| Index | 87 |