Sydney Water Research Articles

Willingness to Pay for Rainwater Tank Features: A Post-Drought Analysis of Sydney Water Users

The Millennium Drought across Australia during the 2000s placed cities under pressure in providing urban water security. In Sydney, Australia’s largest city, a comprehensive water demand programme triggered a significant reduction in per capita water consumption. The water demand programme included incentives for the installation of rainwater tanks. This paper explores the willingness to pay (WTP) for rainwater tank features in the post-drought context. Rainwater tanks have been demonstrated as an effective measure to reduce mains water demand, but they also provide broader environmental and economic benefits, such as the reduction of urban runoff to waterways and deferred capital investment in augmenting capacity of water supply system. Therefore, there is the need to better understand WTP for rainwater tank features across the community. An online survey was administered to a sample of Sydney households, with 127 respondents completing a rainwater tank choice experiment that explored their WTP for different rainwater tank features and the socio-psychological constructs that might influence their tendency to adopt rainwater tanks. The results demonstrated that householders surveyed valued slimline rainwater tanks, as they are likely to be less obstructive, particularly given the trend for smaller lot sizes and increased building size. Householders also placed greater value on connecting the rainwater tank to outdoor demands, which may be influenced by perceived vulnerability of outdoor uses to water restrictions relative to indoor uses. The survey analysis also identified that the householders most receptive to installing a rainwater tank are likely to be conformists, who compare themselves to peers, and spend significant effort when making decisions, and are already taking actions to conserve water. The findings are of significance when targeting future education programmes and designing financial incentives to encourage rainwater tank adoption.

Planning resilient water resources and communities: the need for a bottom-up systems approach

ABSTRACTA robust understanding of water security, and the potential contributions made by alternative management strategies, is needed for a world challenged by population growth and climate-driven resource scarcity. This understanding is vital for realising our visions and plans to build future sustainable and resilient cities that have lesser impacts on increasingly scarce environmental and economic resources. The implications of making average demand assumptions on water security predictions and distribution patterns are investigated using calibrated bottom-up multi-scale numerical (Systems Framework) models of the Greater Melbourne and Sydney water networks and observed demand data. The calibrated Systems Framework models, which are highly spatially and temporally resolved, are progressively modified through erosion of the temporal and spatial granularity of their boundary conditions by replacing demands with various average assumptions. It is shown that average assumptions lead to material differences in model predictive behaviour, and that the directions of these differences are unpredictable and sometimes lead to counter-intuitive outcomes. It is concluded that the application of average assumptions of any kind is problematic (from both pure statistical and numerical modelling standpoints) and has the potential to heavily influence infrastructure investment and, more broadly, policy direction.

MAKING AND KEEPING CUSTOMER PROMISES: SYDNEY WATER’S APPROACH TO PUTTING CUSTOMERS AT THE HEART OF EVERYTHING WE DO

MAKING AND KEEPING CUSTOMER PROMISES: SYDNEY WATER’S APPROACH TO PUTTING CUSTOMERS AT THE HEART OF EVERYTHING WE DO

Impact of a moderate/high-severity prescribed eucalypt forest fire on soil phosphorous stocks and partitioning

This study examines the direct impact of a moderate/high-severity prescribed fire on phosphorous (P) stocks and partitioning in oligotrophic soils of a dry eucalypt forest within Sydney's water supply catchments, Australia. We also quantify and characterize the P present in the ash produced in this fire, and explore its relationships with the maximum temperatures recorded in the litter layer during the burn.In these oligotrophic soils, P concentrations were already relatively low before the fire (<130mgkg−1, mainly in organic forms). The fire consumed the entire litter layer and the thin Oa soil horizon, creating 6.3±3.1tha−1 of ash, and resulted into direct net P losses of ~7kgha−1. The P lost was mostly organic and there was a moderate net gain of inorganic and non-reactive P forms. Importantly, only a small proportion of the post-fire P was bioavailable (equivalent to ~3% of the total P lost during fire). Higher total P concentrations in ash corresponded with higher maximum temperatures (>650°C) recorded in the burning litter layer, but effects of fire temperature on ash P partitioning were not significant.Fire not only transformed P chemically, but also physically. Our results show that, immediately after fire, up to 2kgha−1 of P was present in the ash layer and, therefore, highly erodible and susceptible to be transported off-site by wind- and water erosion. Even if most of this P was, initially, of low bioavailability, its transfer to depositional environments with different geochemical conditions (e.g. anoxic sediments in water reservoirs) can alter its geochemical forms and availability. Further investigation of potential P transformations off-site is therefore essential, particularly given that SE-Australian water supply catchments are subject to recurrent perturbation by prescribed fire and wildfires. The latter have already resulted in major algal blooms in water supply reservoirs.

Australian-made technology renews Sydney's oldest sewers

Like all large cities around the world, Sydney's major underground sewers are deteriorating through age and reaching the end of their service life. To succeed in its vision to be the lifestream of Sydney for generations to come, Sydney Water's active sewer renewals program needs to renew underground sewers beneath heavily populated and environmentally sensitive areas. One of Sydney Water's pipeline rehabilitation contractors, Interflow, recently applied world class spiral wound lining technology to renew two of these sewers without excavation or interrupting services. This Australian made technology is pushing the boundaries in non-disruptive underground sewer renewal previously considered too difficult or impossible. The projects carried out for Sydney Water and discussed in this paper have twice received the International Society for Trenchless Technology's award for international project of the year.

Zoonotic Cryptosporidium Species in Animals Inhabiting Sydney Water Catchments.

Cryptosporidium is one of the most common zoonotic waterborne parasitic diseases worldwide and represents a major public health concern of water utilities in developed nations. As animals in catchments can shed human-infectious Cryptosporidium oocysts, determining the potential role of animals in dissemination of zoonotic Cryptosporidium to drinking water sources is crucial. In the present study, a total of 952 animal faecal samples from four dominant species (kangaroos, rabbits, cattle and sheep) inhabiting Sydney’s drinking water catchments were screened for the presence of Cryptosporidium using a quantitative PCR (qPCR) and positives sequenced at multiple loci. Cryptosporidium species were detected in 3.6% (21/576) of kangaroos, 7.0% (10/142) of cattle, 2.3% (3/128) of sheep and 13.2% (14/106) of rabbit samples screened. Sequence analysis of a region of the 18S rRNA locus identified C. macropodum and C. hominis in 4 and 17 isolates from kangaroos respectively, C. hominis and C. parvum in 6 and 4 isolates respectively each from cattle, C. ubiquitum in 3 isolates from sheep and C. cuniculus in 14 isolates from rabbits. All the Cryptosporidium species identified were zoonotic species with the exception of C. macropodum. Subtyping using the 5’ half of gp60 identified C. hominis IbA10G2 (n = 12) and IdA15G1 (n = 2) in kangaroo faecal samples; C. hominis IbA10G2 (n = 4) and C. parvum IIaA18G3R1 (n = 4) in cattle faecal samples, C. ubiquitum subtype XIIa (n = 1) in sheep and C. cuniculus VbA23 (n = 9) in rabbits. Additional analysis of a subset of samples using primers targeting conserved regions of the MIC1 gene and the 3’ end of gp60 suggests that the C. hominis detected in these animals represent substantial variants that failed to amplify as expected. The significance of this finding requires further investigation but might be reflective of the ability of this C. hominis variant to infect animals. The finding of zoonotic Cryptosporidium species in these animals may have important implications for the management of drinking water catchments to minimize risk to public health.

Model-based methodology for plant-wide analysis of wastewater treatment plants: industrial case study

This paper presents the application of a model-based methodology for improved understanding of the tight interplay between effluent quality, energy use, and fugitive emissions in wastewater treatment plants. Dynamic models are developed and calibrated in an objective to predict the performance of a conventional activated sludge plant owned and operated by Sydney Water, Australia. A scenario-based approach is applied to quantify the effect of key operating variables on the effluent quality, energy use, and fugitive emissions. Operational strategies that enable a reduction in aeration energy by 10–20% or a reduction of total nitrogen discharge down to 3 mg L−1 are identified. These results are also compared to an upgraded plant with reverse osmosis in terms of energy consumption and greenhouse gas emissions. This improved understanding of the relationship between nutrient removal, energy use, and emissions will feed into discussions with environmental regulators regarding nutrient discharge licensing.

Managing expectations for sustainability in a changing context – in Sydney's –inner west – a GreenWay governance case study

This case study documents the actions taken by a community to create a greenway in a medium density urban environment in Sydney's inner west, the Cooks River to Iron Cove GreenWay. The vision is to create a pedestrian and cycle path through regenerated bushland and urban parks, making use of a disused rail corridor. The 5 km corridor aims to link the community and natural environment to two of Sydney's water assets, and is consistent with state and local government goals to create a more sustainable and liveable urban environment. The GreenWay came tantalisingly close to being realised, until the political context changed. The case study explores: the phases of the GreenWay project; the capacity of the community to plan its own future; and the subsequent interactions between government and community. We highlight the role community, government and external bodies can have in urban ecological retrofitting and in designing innovative and inclusive governance models for sharing a public asset; and draw out lessons for managing community engagement, expectations, frustrations and trust in a changeable environment, both socially and politically. We also recognise the ongoing task of building social and institutional capacity towards a single vision.

Trends in water quality data in the Hawkesbury–Nepean River System, Australia

The Hawkesbury–Nepean River System (HNRS) is one of the most important inland river systems in Australia, which supplies over 90% of Sydney's potable water. In this paper, 25 water quality parameters from nine sampling stations in the HNRS covering a period of 12 years are used to examine the trends in the water quality data in the HNRS. It has been found that there is an overall increasing trend of turbidity, chlorophyll-a, alkalinity, total iron, total aluminium, total manganese and reactive silicate, indicating an overall water quality deterioration in the HNRS during the last decade. The parameters such as phosphorus, suspended solids and ammonical nitrogen do not show any marked change over the period of study. Although an improvement in water quality can be seen at some stations downstream of the undisturbed parts of the catchment, there is a clear trend of increased chemical and physical water quality deterioration at many locations in the HNRS. Better land use planning is recommended to achieve an overall improvement in the water quality of the HNRS in future.

Build Level of Services and Customer Value Into Decision Making: Sydney Water’s Water Main Asset Management Strategy

Sydney Water’s water network consists of about 21,000 km of water mains. Sydney Water is a statutory state owned corporation, with the Independent Pricing and Regulatory Tribunal as the economic regulator. Sydney Water has developed a comprehensive set of decision frameworks and business processes to manage the life cycle of water main assets to achieve a desired level of service and financial return within an acceptable risk. With the current constrained financial and economic environment, affordability is the most pressing issue in the water industry as customers are seeking value for money. It is requiring the water industry to reduce capital investment programs and deliver more with less while maintaining or improving customer satisfaction. This paper presents the analysis of the asset performances and customer expectations against the level of services and explains how Sydney Water explores the opportunities to build the level of services and customer value into its asset management strategy and decision framework to optimise the capital investment programs.

Plant-wide Optimization of a Full-Scale Activated Sludge Plant with Anaerobic Sludge Treatment

This paper presents the application of a plant-wide model-based methodology to wastewater treatment plants. The focus is on a tertiary activated sludge plant with anaerobic sludge treatment, owned and operated by Sydney Water. A dynamic plant-wide model is first developed and calibrated using historical data. A scenario-based optimization procedure is then applied for computing the effect of key discharge constraints on the minimal net power consumption, via the repeated solution of a dynamic optimization problem. The results show a potential for reduction of the energy consumption by about 20%, through operational changes only, without compromising the current effluent quality. It is also found that nitrate (and hence total nitrogen) discharge could be reduced from its current level around 22 mg(N)/L to less than 15 mg(N)/L with no increase in net power consumption, and could be further reduced to <10 mg(N)/L subject to a 15% increase in net power consumption upon diverting part of the primary sludge to the secondary treatment stage. This improved understanding of the relationship between nutrient removal and energy use will feed into discussions with environmental regulators regarding nutrient discharge licensing.

Build level of services and customer value into decision making: Sydney Water's water main asset management strategy

Build level of services and customer value into decision making: Sydney Water's water main asset management strategy

Use of nanofiltration and reverse osmosis in reclaiming micro-filtered biologically treated sewage effluent for irrigation

Micro-filtered, biologically treated sewage effluent (BTSE) generally has high sodium adsorption ratio (SAR) and sodium (Na) and chloride (Cl) concentrations. Therefore it cannot be directly used for irrigating sensitive crops. A study was conducted on a micro-filtered BTSE from a Sydney water treatment plant to determine whether the BTSE can be treated using nanofiltration (NF) and reverse osmosis (RO) to bring these risk parameters within safety limits. The study showed that using NF and RO alone could not produce the required ratio of SAR. Furthermore, NF alone did not remove the necessary levels of Na and Cl ions while RO did. However, blending equal proportions of NF permeate and RO permeate obtained from a two stages hybrid treatment system consisting of NF followed by RO resulted in a product quality suitable for irrigation in terms of the above mentioned risk factors. Utilizing NF prior to RO reduced the RO membrane fouling as well. Both NF and RO removed most of the pharmaceutical and personal care products from the feed water and this may subsequently protect soil and ground water from potential hazards.

Sydney Water Corrosion and Odour Management Tool

Sydney Water Corrosion and Odour Management Tool

Water‐saving impacts of Smart Meter technology: An empirical 5 year, whole‐of‐community study in Sydney, Australia

AbstractIn 2009–2010 Sydney Water, the primary water utility in Sydney, conducted a comprehensive Smart Metering trial in residential homes in the suburb of Westleigh, in Sydney's north. The trial involved 1923 participants residing in 630 households. A whole‐of‐community method of engagement was applied to capture the views of residents from 12 to 70+ years of age. The trial examined the effects of the technology on the water consumption of an intervention group compared with that of a matched control group. After removing properties that had been sold since the beginning of the trial, properties in the study group were matched with a control group property on the basis of the household size, property size and the presence (or otherwise) of a swimming pool. The effects of the technology on consumption were measured and analyzed for the period July 2009 to June 2010, coupled with qualitative information that was collected throughout the duration of the study. A key finding was that households with the in‐home display (IHD) installed, reduced their consumption by an average of over 6.8% over the study period when compared to the control group. Since completion of the study the community has not had any further interventions. The trial created an opportunity to examine the longer‐term effects of the technology (June 2008 to September 2013). Consumption data collected over the 3 year posttrial period revealed that the participant group consumed 6.4% per month less water when compared to the pretrial period, whilst the matched control group consumed 1.3% per month more water when compared to the pretrial period. The reduced consumption of the participant group was maintained over time, demonstrating the long‐term value of this technology.

Managing complexity in Australian urban water governance: Transitioning Sydney to a water sensitive city

Recognising Australia's need for water management that better supports urban populations facing increasing socio-ecological challenges, the study on which this article is based brought together professionals from Sydney's water sector to understand what they believe is entailed in transitioning Sydney to a water sensitive city. Participants called for new institutional arrangements requiring collaboration and leadership from various levels of government, community groups and individual community members. We adopt Tainter's model of social complexification as an analytical framework for considering the implications of the research findings. From the perspective of this model, we argue that the proposed arrangements would involve, along with the envisioned benefits, increasing complexity and commensurate costs, with important consequences for the forms that water sensitive cities might take. Considerations relating to the costs of complexity take on particular importance in futures for which reduced material affluence appears increasingly possible. The costs of complexity under such conditions may be more readily ameliorated via pathways that entail increased local responsibility for meeting water needs, such as decentralised rainwater harvesting. We argue that increased participation in water-related governance and responsibility for related infrastructure will follow more readily from measures to foster local enthusiasm than from mandated approaches that themselves require increased complexity.

Thermal tolerance of early development in tropical and temperate sea urchins: inferences for the tropicalization of eastern Australia

The thermal envelope of development to the larval stage of two echinoids from eastern Australia was characterized to determine whether they fill their potential latitudinal ranges as indicated by tolerance limits. The tropical sand dollar, Arachnoides placenta, a species that is not known to have shifted its range, was investigated in Townsville, northern Australia (19°20′S, 146°77′E), during its autumn spawning season (May 2012). The subtropical/temperate sea urchin, Centrostephanus rodgersii, a species that has undergone poleward range expansion, was investigated in Sydney, southern Australia (33°58′S, 151°14′E), during its winter spawning season (August 2012). The thermal tolerance of development was determined in embryos and larvae reared at twelve temperatures. For A. placenta, the ambient water temperature near Townsville and experimental control were 24 °C and treatments ranged from 14 to 37 °C. For C. rodgersii, ambient Sydney water temperature and experimental control were 17 °C, and the treatment range was 9–31 °C. A. placenta had a broader developmental thermal envelope (14 °C range 17–31 °C) than C. rodgersii (9 °C range 13–22 °C). Both species developed successfully at temperatures well below ambient, suggesting that cooler water is not a barrier to poleward migration for either species. Both species presently live near the upper thermal limits for larval development, and future ocean warming could lead to contractions of their northern range limits. This study provides insights into the factors influencing the realized and potential distribution of planktonic life stages and changes to adult distribution in response to global change.

A review of policy, legal, land use and social change in the management of urban water resources in Sydney, Australia: A brief reflection of challenges and lessons from the last 200 years

The management of water in Sydney, Australia, is marked by tragedy, foresight, protectionism and social upheaval. The settlement of the first fleet colony at Sydney was determined by its water assets with its sheltered and deep harbour and access to reliable freshwater for the soon to be burgeoning town. During the first 100 years of European settlement, the management of Sydney's water resources was characterised by minimal planning and arguably contempt for any regulatory regime, culminating in a pandemic of water borne diseases and pollution. From a perilous beginning beset by drought and disease, water management evolved over the next century to achieve what was at the time world's best practice in sanitary engineering and laying the foundation for the water systems that occur today. These achievements relied on a centralised approach, which solved water supply and sanitation issues but created a new set of environmental problems such as the discharge of diffuse water pollution into urban streams. As the city of Sydney moves into its third century, water management remains a critical issue for state and local government. This has occurred through the convergence of a range of social, political, climatic and environmental factors, each with their own separate but interrelated and overlapping agendas. Sydney still defines its essential character in terms of its harbour, beaches and waterways. If urban water management is to be a central foundation for a sustainable future for Sydney, reforms are needed and necessary.

Sustainable buildings and infrastructure: paths to the future

1. Drivers of Sustainability in the Built Environment 2. History of Sustainability in the Built Environment 3. Sustainability Policies and Programs 4. Green Rating Systems 5. Project Delivery and Pre-design Sustainability Opportunities 6. Sustainable Design Opportunities and Best Practices 7. Sustainable Construction Opportunities and Best Practices 8. Post-occupance Sustainability Opportunities and Best Practices 9. The Business Case for Sustainability 10. Trends for theFutire of Sustainable Design and Construction Case Studies Air Force Weather Agency, Nebraska. Air Reserve Base Fire Station, Homestead (FL). Center One Building, Seoul. Freedom Park, Naples (FL). Gran Torre Costanera, Santiago. Hotel Intercontinental, Santiago. Olympic Venue, London. Masdar, UAE. One Island East, Hong Kong. The People's Place Library, Antigonish. Songdo IBD, Incheon. Sydney Water Headquarters. Torre Titanium La Portada, Santiago. United Nations Offices, Nairobi. Visionaire Hotel, New York

Editorial: In Memoriam of Associate Professor Dr Elaine Lawrence

Despite being a graduate of the rigorous Bachelor of Information Technology at the University of Technology, Sydney (UTS) in 1996, I was unfortunate in that I missed being taught by Associate Professor Elaine Lawrence who began working at UTS in 1990 as a Lecturer in Computing Science. Dr Lawrence became a senior lecturer in 2000, and subsequently an associate professor in 2006. Our paths crossed in 2002 when I was tasked deliver a new course entitled eBusiness Principles in my first year of lecturing at the University of Wollongong, and after an initial scurry find an adequate textbook, I came across Dr Lawrence's groundbreaking text Internet Commerce: Digital Models for Business. Lawrence's book was a best-seller for Wiley, adopted by almost every course coordinator teaching e-business/e-commerce in Australia, at a time when information technology had burgeoning undergraduate numbers. When my PhD supervisors, Professor Joan Cooper and Associate Professor Carole Alcock, suggested me that Dr Lawrence would be a good choice for an examiner in 2003, I must say I was more than a little nervous. After doing some background research on the web see the fit, I was in even greater awe noting the impact Dr Lawrence was having on the teaching of industry certifications, and the creation of new courses. Elaine was the Program Leader of the popular Masters of Internetworking degree at UTS and as a qualified Cisco Certified Academic instructor (CAI) she began the CISCO certification courses delivered at UTS, in addition contributing a plethora of materials the CISCO Academy that were used by an estimated one million persons globally. Lawrence also tested international teaching materials for CISCO in Ireland and the United States and was the NSW representative for the Educational Council for CISCO. I had spent five years at Nortel Networks, a CISCO competitor, and immediately felt an affinity with her background Dr Lawrence was the first student complete the Doctor of Technology at Deakin University in 2001. In addition this, Dr Lawrence had a Masters of Business Information Technology, a Graduate Diploma in Commercial Computing and a Bachelor of Arts (awarded the university prize for Journalism). She was a very active senior member of the Australian Computer Society (ACS) for more than 20 years and also a member of the Institute of Electrical and Electronics Engineers (IEEE). In 1994 she began her own company called CyberConsult who had among its customers, Sydney Water, the Australian Institute of Management, Unilink and the Australian Computer Society. I do remember being taken by the fact that her slogan for her consulting business was The Human Side of Technology. Given my thesis was all about emerging technologies and their implications, I found peace in the fact that Dr Lawrence was a potential marker. After receiving my PhD I corresponded with Dr Lawrence, appreciative of her genuine feedback on my thesis and ways improve it. She was the perfect academic role model for me, and a wonderful mentor from the outset, although our relationship just developed naturally and we enjoyed corresponding with one another without the labels of mentor and mentee. I remember distinctly that Dr Lawrence had a way with words and she was always armoured with a graceful and tactful way of providing advice. She was reassuring at first, then encouraging, and then quite direct using sentences like why don't consider submitting research to or you know this audience would be quite accepting of this perspective. Amazingly Elaine never seemed in a rush, and yet somehow she did so much! She always made feel important in her presence and that she had all the time in the world for you. In 2003, I had the opportunity contribute Dr Lawrence's best seller, and began work on a number of fresh case studies for the latest edition of Internet Commerce which was in fact Elaine's second book. …