Planning for sustainable urban water: Systems-approaches and distributed strategies

Transcription

1 Planning for sustainable urban water: Systems-approaches and distributed strategies Simon Anthony Fane Institute for Sustainable Futures University of Technology, Sydney Thesis submitted for the PhD in Sustainable Futures 2005

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3 Statement of original authorship I certify that the work in this thesis has not previously been submitted for a degree nor has it been submitted as part of requirements for a degree. I also certify that the thesis is an original piece of research written by me, except where noted in the text. Any help that I have received in my research work and the preparation of the thesis itself has been acknowledged. In addition, I certify that all information sources and literature used are indicated in the thesis. Signature of candidate: Simon Anthony Fane i

4 This thesis is dedicated to love and hope: Love of my partner Wendy and children Alexander and Madeline, and Hope for a sustainable future. ii

5 Acknowledgements Whether I would have ever started on the journey that is presented in this thesis if it were not for my father, is a question for a psycho-analyst; whether I would have finished it without his advice, encouragement and editing is less in question. Thank you dad for your counsel, your interest and your unending support. Various people have worked with me on aspects of the research presented within this thesis. I would like to acknowledge and thank my supervisor Professor Stuart White for his support, intellectual input (particularly in relation to least cost planning) and his continuing optimism. I would also like to acknowledge and thank my co-supervisor Professor Nick Ashbolt from the University of New South Wales for his significant contribution and guidance in relation to the part of the research that focused on the assessment of waterborne disease risk. The work of my colleagues at the Institute for Sustainable Futures must also be acknowledged. In particular, the team who worked with me on the Sydney Metropolitan Water Strategy project. The report from that project forms an Appendix to this thesis. The efforts of Nicholas Edgerton for his endeavours on the final report and Sally Campbell, Kate Beatty, and Meenakshi Jha for their labours in options modelling need to be recognised here. I would also like to thank the NSW Department of Infrastructure, Planning Natural Resources for allowing me to include the report. Thanks also to my fellow postgraduate students at the Institute, including Chris Reardon, Chris Riedy, Claire Gerson, Gabrielle Kuiper, Kumi Abeysuriya, Michelle Zeibots and Wahidul Biswas for their thought provoking discussions, enthusiasm and friendship at different times. Financially, I must thank the Australian Research Council for the support of a postgraduate award; Sydney Water Corporation for contributing a top up stipend; the Institute for Sustainable Futures for travel funds to various conferences; and the MISTRA Urban Water Program for providing me with an airfare to Sweden. Finally, to my friends and family, thank you for your love and encouragement throughout the long journey. iii

6 Table of Contents Statement of original authorship...i Acknowledgements..iii Table of Contents.vi List of Tables..viii List of Figures...ix List of relevant publications..x Abstract...xii 1 General Introduction 1.1 Introduction Urban water and the challenge of sustainable development Research objectives Content and structure The context of this work A readership beyond urban water.9 2 Sustainable development and sustainable urban water 2.1 Introduction Conventional approaches to urban water Sustainable development Conceptualising sustainable urban water Systems-thinking Perspectives on the urban water system Perspectives on the system-environment of urban water Summary Approaches to sustainable urban water Water sensitive urban design Ecological sanitation Ecological Engineering Advanced treatment The soft path for water Summary..46 iv

7 2.6 Synthesis and discussion Developing a pluralist stance Distributed strategies Summary Conclusions.56 3 Assessing sustainable urban water 3.1 Introduction A theoretical basis for assessing sustainable urban water System definition System analyses and assessment Uncertainty Summary Techniques available for assessing sustainable urban water Biophysical techniques Socio-economic techniques Multi-criteria integration techniques Summary A review of work to date assessing sustainable urban water Introduction to an emerging field Assessments of biophysical criteria Socio-economic assessments Large group programs Summary Identifying areas for further work Whole system methods Accounting for distributed strategies in assessments Multi-criteria integration Managing subjectivity Managing complexity Summary Conclusions v

8 4 Whole-system microbial risk assessment 4.1 Introduction Waterborne pathogens, sustainable urban water and risk assessment The whole-system microbial risk assessment method outlined Previous whole-system models in the food production sector Modelling framework Pathogen generation models System models Hygiene impact model PAPER ONE: Life cycle microbial risk analysis of sustainable sanitation alternatives PAPER TWO: A methodology for assessing comparative pathogen impact from novel wastewater recycling systems PAPER THREE: Decentralized urban water reuse: The implications of system scale for cost and pathogen risk Conclusions Equivalent assessment of demand- and supply-side options 5.1 Introduction Integrated resource planning, least cost planning and end-use modelling Integrated resource planning Least cost planning The role of least cost planning in integrated resource planning A review of currently used least-cost analysis methods Calculating the avoided cost of water supply Calculating the cost-benefit of water conservation Calculations of the levelised cost of water conservation Problems with the current least cost analysis methods PAPER FOUR: The Use of Levelised Cost in Comparing Supply and Demand Side Options PAPER FIVE: Levelised cost, a general formula for calculations of unit cost in integrated resource planning REPORT ONE: Meeting Sydney s Water Demand-Supply Balance.182 vi

9 5.7 Conclusions Least cost planning for sustainable urban water 6.1 Introduction Backcasting, sustainability limits, externalities and cost analysis Backcasting Environmental economics, ecological economics, and externalities A framework of externalities and constraints for urban water The least cost sustainable scenario method Least cost scenario analysis Developing a framework of goals, constraints and externalities A generalised methodology PAPER SIX: The secret life of water systems: Least cost planning beyond demand management PAPER SEVEN: What are the Implications of Distributed Wastewater Management in Inner Sydney Conclusions Discussion and conclusions 7.1 Introduction Distributed strategies and sustainable urban water Pluralism and sustainable urban water Systems-approaches in the assessment of sustainable urban water Service-defined systems analyses Areas for further work Additional whole-system methods for sustainable urban water Further applications of whole-system microbial risk assessment A framework for evaluation of demand- and supply-side options Towards integrated planning for sustainable urban water Final conclusions References vii

10 List of Tables Table 2.1 Approaches and strategies for sustainable urban water...46 Table 2.1 A summary of potential sustainability issues for urban water...48 Table 3.1 Sustainability issues for urban water that might be addressed through MFA...69 Table 3.2 Sustainability issues for urban water addressed by technical risk assessment...72 Table 3.3 Priority criteria and techniques from Hellstrom et al..98 Table 3.4 Whole-system methods for assessing sustainable urban water.101 viii

11 List of Figures Figure 2.1 Linear flows of nutrients water and contaminates induced by the conventional approaches to urban water.13 Figure 2.2 Social and ecological systems impose limits on the development of anthropogenic (human made) and economic systems.17 Figure 2.3 Spheres of influence in the system-environment of urban water 23 Figure 2.4 The local system-environment of urban water...24 Figure 2.5 Approaches to urban water and sustainable urban water...28 Figure 2.6 A comparison of water sensitive and conventional drainage.29 Figure 2.7 The advantages of the Eco-San concept. 33 Figure 2.8 The Stensund wastewater aquaculture...36 Figure 2.9 The NEWater plant - wastewater treatment chain...39 Figure 2.10 The end-use break down of water use in a household..43 Figure 2.11 Diagrams of alternative urban water infrastructures 52 Figure 3.1 The spectrum of system definitions for urban water..61 Figure 4.1 Whole-system microbial risk assessment modelling framework.118 Figure 4.2 An example of a system model constructed of hygiene modifying units 121 Figure 5.1 Integrated resource planning: An iterative framework 155 Figure 5.2 A conservation supply curve from a study of water conservation options for the Australian Capital Territory ix

12 List of relevant publications Papers included within this thesis: Fane, S., Turner, A., and C. Mitchell, (2004) The Secret Life of Water Systems: Least Cost Planning Beyond Demand Management 2nd IWA Leading Edge Conference on Sustainability in Water Limited Environments, Sydney, November Fane S., (2003), Life cycle microbial risk analysis of sustainable sanitation alternatives, Proceedings 2 nd International Eco-San Symposium, conference, Lubeck, Germany, April 2003 Fane S, Robinson J., and S. White, (2003), The Use of Levelised Cost in Comparing Supply and Demand Side Options, Wat. Sci. Tech: Water Supply, Vol 3:3 Fane S., and S. White, (2003), Levelised cost, a general formula for calculations of unit cost in integrated resource planning, Proceedings Efficient 2003: Efficient Use and Management of Water for Urban Supply, Tenerife, Spain, April 2003 Fane S., Ashbolt N., and S. White, (2002), Decentralized urban water reuse: The implications of system scale for cost and pathogen risk, Wat Sci Tech, Vol 46:6 Fane S., and S. White, (2001), What are the Implications of Distributed Wastewater Management in Inner Sydney? Proceedings International Ecological Engineering Conference, Christchurch, New Zealand, November 2001 Fane S., and N. Ashbolt, (2000), A methodology for assessing comparative pathogen impact from novel wastewater recycling systems. Proceedings Water recycling, Adelaide, Australia, September 2000 Other relevant publications: Fane A. and S. Fane, (2005), The Role of Membrane Technology in Sustainable Decentralized Wastewater Systems, Wat Sci Tech, Vol 51:10 Fane, S., Willetts, J., Abeysuriya, K., Mitchell, C., Etnier, C., and S. Johnstone, (2004), Evaluating reliability and life-cycle cost for decentralized wastewater within the context of asset management, Proceedings 6th Specialised Conference on Small Water & Wastewater Systems AND 1st International Conference on Onsite Wastewater Treatment & Recycling, Fremantle, Australia, February, 2004 Mitchell, C., Turner, A., Cordell, D., Fane, S. and S. White, (2004), Water conservation is dead: long live water conservation, 2nd IWA Leading Edge Conference on Sustainability in Water Limited Environments, Sydney, November White S., and S. Fane, (2002), Designing Cost Effective Water Demand Management Programs in Australia, Wat Sci Tech Vol 46:6 Jha, M., Mouritz M., Smith P., and S. Fane, (2001), Integrated Water Management System in An Urban Redevelopment In Sydney, Proceedings International Ecological Engineering Conference, Christchurch, New Zealand, November 2001 x

13 Malmqvist, P.A., Ashbolt N., Fane S., Hellstrom D., Jeppsson U, and H. Soderberg, 2000, Assessing Alternative Wastewater systems in Hammarby Sjostad Stockholm. Proceedings Decision support in Civil engineering, Lyon, France, November 2000 Fane, S., Ashbolt, N., and S. White, (1999), Incorporating waterborne pathogen data into decision support frameworks for evaluating sustainable sanitation options, Proceeding from the international ecological engineering conference, Aas, Norway. June 1999 Fane, S., Robinson, D. and S. White, (1998), Reduce, reuse or recycle? Economic evaluation of measures for improving environmental outcomes from wastewater systems, in: A.I. Schafer, L. Basson & BS Richards (eds), Environmental Engineering Research Event, Sydney: UNESCO Centre for Membrane Science & Technology, December, p xi

14 Abstract This thesis develops and applies a number of methods for systems analysis and assessment within the field of sustainable urban water. These focus on the evaluation of distributed strategies. In line with arguments made within the thesis, the methods developed assess urban water on a whole-system basis, with the system defined in terms of the services provided. Further, the thesis argues for sustainable urban water planning to take a pluralist stance; both in the conception of sustainable urban water and the strategies considered. The challenges of sustainability and sustainable development are fundamentally problems of complex systems. Planning and assessment of sustainable urban water therefore require a systems-approach. Systems-thinking is not, however, a unified body of knowledge and this thesis develops a unique perspective on systems-thinking which is used to critically review the fields of sustainable urban water and its assessment. Within these reviews, the thesis develops a framework for understanding sustainable urban water in terms of a number of varied approaches, and describes a feasible theoretical basis for assessing sustainable urban water. Many, so called, sustainable strategies are small-scale and distributed in nature. Distributed strategies include decentralised systems, embedded technologies, and local measures for conservation. Traditional systems analysis methods have failed to account for distributed strategies. To adequately include distributed strategies, this thesis argues that assessment methods will need to be based on whole-system modelling, utilise enduse models of service provision, and include - in the form of a demand forecast - a time dimension in relation to service provision. This thesis proposes new methods for microbial risk assessment on a whole-system basis and Least cost planning for (urban water) Sustainable Scenarios (LeSS). A novel evaluation framework for least cost planning for water supply, which provides an equivalent comparison of demand- and supply-side options, is also developed. These methods are illustrated through case studies. These case studies illustrate the potential of distributed strategies. When assessed on an equivalent basis, in various examples, distributed strategies are shown to be particularly cost effective. Decentralised xii

15 wastewater reuse systems are also shown to impose a theoretically lower level of pathogen risk on the community than equivalent centralised reuse schemes. Despite the advances in assessment methodologies made within the thesis, further development of practical tools for assessing and planning sustainable urban water remains an urgent goal. xiii