New approaches to residential and commercial greenfield development Sydney Water has been actively working with a variety of stakeholders, including stare agencies, local government, other utilities and private developers co establish a benchmark for providing sustainable water services co the proposed greenfield development at H oxcon Park. Hoxcon Park is in Sydney's south west and iris expected char 15,000 dwellings will be developed over che next 12-20 years. Sydney Water co mmissioned investigations co determine the best servicing strategy fo r minimising demand for potable water and che export of wastewater from proposed developments in rhe Hoxcon Park area. Sixteen options were developed chat could achieve these aims co varying extents. All options involved water efficient fittings and fixtu res and rhe use of alternative water supplies for non-potable uses, such as toiler fl ushing and outdoor use. Alternative water supplies investigated included rainwater ranks, recycled water from ST Ps or from sewer mining and greywarer recycli ng.
The options were initially subject co a "fatal flaw analysis" co determine chose that should be subject co detailed investigation. The analysis was undertaken by a multidisciplinary ream which analysed the feasibility of che options. For example, precinct-based and local STPs were eliminated because they were more expensive and had a significant risk of salinity build up from multiple passes th rough a closed loop system. Following the initial analysis, a multi-cri teria analysis (MCA) was undertaken on the remaini ng eight options. The cri reria used in the analysis included life cycle assessment, energy use, health risks and visual impact. As a result of the MCA three options were shortlisted. These were: • conventional servicing • potable supplies supplemented with water from rainwater tanks for toiler and outdoor use • potable supplies supplemented with recycled water from the nearby proposed H olsworchy recycled water scheme These three options were investigated further, with rhe recycled water option being selected based on the potential ro minimise potable water use and discharges ro receiving waters. Lessons learnt from the Rouse Hill Recycled Water scheme will be incorporated at H oxron Park, particularly the need to incorporate storage capacity co meet highly variable demands and the importance of focuss ing on water conservation, regardless of the water source. 48 MAY 2004
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Onsite wastewater systems In Austral ia onsice wastewater systems have been predominantly used in rural settings. These systems are now gaining more support in urban areas due ro increased co mmunity awareness of rhe need for water conservation and improvements in onsite system technologies and opportunities. Sydney Water is undertaking a number of projects to test technologies and investigate issues surrounding the use of onsite wastewater systems in urban and peri-urban areas. These projects will serve as demonstration projects fo r both Sydney Water and rhe public. Two new projects are now starting at Galston High School (residential application) and Parramacca Civic Place (co mmercial application). Galston High School Sydney Water is investigating options for providing onsice treatment in areas where the cost of co nventional reticulated services is prohibi tive such as "back-log" areas. A pilot onsice wastewater management project has been initiated ac Galston High School on the rural fringe of northern Sydney. The school currently has rradicional septic rank pump out services.
Sydney Water is currently co nducting prelim inary studies of risks, soils and topography co allow the selection of a preferred on-site solu tion. If these studies show chat an on-s ite solucion is feasible, Sydney Water will work with the school and local counci l ro implement on-sire waste water treatment generating recycled water that can be used fo r sub-surface irrigation of open spaces ac the school. Parramatta Civic Place Sydney Water will be relocating co new premises in Parramatta in 2006. The new building will be both water and energy efficient and will be pare of an overall redevelopment of rhe city block currently occupied by Civic Place in rhe centre of Parramacca. This provides an opportunity co demonstrate sustainable redevelopment of a commercial building in a heavily urbanised city centre. This type of project is not yec common in che Sydney area. Sydney Water has undertaken studies co develop options for water efficiency measures including water efficient design and fixtures, on-sire treatment and reuse of wastewater and capture and reuse of rai nwater and srormwacer. The building will be designed ro allow rhe water conservation initiatives co be demonstrated and studied by building and development professionals as well as the general public. Because the building will be part of a larger re-development, Sydney Water and
Parramacca Cou ncil are also investigating rhe potential fo r comm unity based approaches for providing sustainable water cycle management solutions for the whole site, rath er than approaching che servicing on a building by buildi ng basis. A guiding principle for the servicing approach will be rhac initiatives muse be cost effective, reliable and economic co operate and maintain. Sydney Water's intent is co provide a case study chat will be practical and economically feasible for ocher developers to adopt. Sydney Water will work with the Green Building Council and other stakeholders during the project co disseminate the lessons being learned as various issues and challenges arise through che project. Recycled Water for Industrial Users
Sydney Water also has a number of schemes providing recycled water for commercial and industrial users. Currently Sydney Water recycles 36.3 ML/day. Of chis 77% is associated with recycling within sewage treatment plants (STPs), 19% fo r irrigation and 4% for residential recycling. T his figure will increase by 20ML/day in August 2004. As part of the Illawarra Wastewater Strategy, Syd ney Water has commissioned works co upgrade Wollongong Sewage Treatment Plane (STP) and co transfer sewage flows from Bellambi and Pore Kembla catchments co Wollongong. This STP will produce at lease 20 ML of near-potable created effluent each day. The recycled water will be transferred co rhe nearby steelworks for industrial uses. There is further scope co expand rhe production of recycled water co accommodate increases in demand either at che steelworks or in ocher uses nearby. This project comes on scream during 2004 and will be one of the largest recycled water schemes in Australia. In future schemes, Sydney Water will apply lessons learned from chis project, in terms of technology and commercial agreements and ocher instru ments required ro ensure chat Sydney Water's costs are recovered whilst customers realise a commercial advantage. Agricultural Reuse of Treated Wastewater Sydney Water has a number of schemes chat provide recycled water for irrigation purposes such as golf courses and agricultural users. These projects replace potable or river water used for irrigation, with recycl_ed water. Sydney Water provides recycled water from the West Camden STP co nearby agricultural land operated by rhe University of Sydney. In addition, Sydney Water has created agricultural businesses around the Picton and Gerringong-Gerroa STPs. As