Where does the water we drink come from? Is there enough for everyone? Where will it come from? Hong Kong's water supply comes from two sources: the rainfall we collect in our reservoirs (20-30%) and water we buy from the Mainland (70-80%). The current agreement for water from the Dongjiang, a tributary of the Pearl River, will expire in 2015. With demand for water growing sharply throughout the Pearl River Delta and the supply of water compromised by pollution and climate change, Hong Kong's future access to clean water is far from certain. In our drive to become a sustainable city, should Hong Kong become self-sufficient? Should we increase the size of our reservoirs? Follow Singapore and recycle our waste water? Build plants to desalinate seawater? What other possible methods are there? Who's going to pay? CitySpeak invites you to join Hong Kong officials, academics and planners in this discussion about our water issues. The keynote speaker is Mr. LT Ma, Director of the Water Supplies Department, who will set the scene and outline the current situation in Hong Kong. The discussion will be moderated by Mr. Mike Kilburn, Environmental Programme Manager, Civic Exchange. Background reading "Liquid Assets -- Water security and management in the Pearl River Basin and Hong Kong" by Civic Exchange, November 2009 (http://www.civic-exchange.org/eng/upload/files/091204LiquidAssets.pdf). For more information about water in China, visit http://www.asiawaterproject.org/. Civic Exchange is a Hong Kong independent non-profit think tank. See: www.civic-exchange.org Designing Hong Kong is a not-for-profit organisation focused on sustainable urban planning. See: www.designinghongkong.com

1. City Speak - The Water We Drink: Water Treatment Technology and Demand Management Bevis Mak Executive Director, Water, AECOM 15 May 2010

3. A Brief History of Water Treatment

6. What is in our raw water?

9. Treatment Philosophy and Method

14. The Process Diagram Page

15. Before and After Clarification Page Solids formed after coagulation and flocculation

16. Traditional Clarifiers Page

22. Sustainable Water Resource Planning

23. Sustainable Water Resources Planning Portfolio Conservation Reuse Desalination Groundwater Surface Water Brackish Water Sea Water General Indirect Potable Direct Potable

24. Sustainable Water Resource Planning Demand Management

26. Sustainable Water Resource Planning New Water Source – Seawater Desalination

28. Seawater Desalination – Thermal Process Page Al Hidd MED Plant, Bahrain (273 ML/d)

30. Membrane Pore Size Smaller than Most Microorganisms 0.0001 0.001 0.01 0.1 1 10 100mm hair Crypto- sporidium smallest micro-organism polio virus MF/UF: -0.2 to 2.0 bar (1 bar = 10m depth of water) NF: 5 to 9 bar RO: 10 to 100 bar Suspended solids Parasites Bacteria Org. macro. molecules Viruses Colloids Dissolved salts Sand filtration Microfiltration Ultrafiltration Nanofiltration Reverse Osmosis

32. Process Diagram Page

34. Sustainable Water Resource Planning New Water Source – Reclamation / Reuse

37. Summary and Conclusion

40. But …we do not wish to see this again! Page So, conserve now!

41. Thank You