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<strong>Sustainable</strong> <strong>subdivisions</strong>:Review of technologies for integrated water services


CRC for <strong>Construction</strong> <strong>Innovation</strong> participantsI N D U S T R YG O V E R N M E N TDepartment of Main RoadsDepartment of Public WorksDepartment of State Development,Trade and <strong>Innovation</strong>R E S E A R C H


<strong>Sustainable</strong> <strong>subdivisions</strong>:Review of technologies for integrated water servicesClare Diaper, Grace Tjandraatmadjaand Steven Kenway


© Icon.Net Pty Ltd 2007Cooperative Research Centre for <strong>Construction</strong> <strong>Innovation</strong>9th Floor, L Block, QUT, Gardens Point2 George Street, Brisbane, Qld, Australia 4000Telephone: +61 7 3138 1393Email: enquiries@construction-innovation.infoWeb: www.construction-innovation.infoAll intellectual property in the ideas, concepts and design for this publication belongs to Icon.Net Pty Ltd.The authors, the Cooperative Research Centre for <strong>Construction</strong> <strong>Innovation</strong>, Icon.Net Pty Ltd, and their respectiveboards, stakeholders, offi cers, employees and agents make no representation or warranty concerning the accuracy orcompleteness of the information in this work. To the extent permissible by law, the aforementioned persons excludeall implied conditions or warranties and disclaim all liability for any loss or damage or other consequences howsoeverarising from the use of the information in this book.First published 2007 by Cooperative Research Centre for <strong>Construction</strong> <strong>Innovation</strong> for Icon.Net Pty Ltd.Images:front and back cover; and pages vi, 6, 8, 9, 10: Clare Diaperpages 5, 12, 13, 17: Grace TjandraatmadjaThis publication forms part of the <strong>Construction</strong> <strong>Innovation</strong> <strong>Sustainable</strong> <strong>subdivisions</strong> series comprisingEnergy-effi cient Design published in 2005 and Ventilation (available early 2008).For information on obtaining our publications, please visit www.construction-innovation.infoThis publication is printed on 9lives 80 by Spicers Paper. This paper is derived from well managed forests andcontains 80% recycled fi bre from post-consumer waste and 20% totally chlorine free pulp. It is ISO 14001 accreditedand FSC (Forest Stewardship Council) certifi ed.This publication has been printed using soy-based inks.RRP $19.25 (including GST)ISBN 978-0-9803503-9-5


ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1Residential water use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2SEQ — Current strategies and initiatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Factors affecting technology selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Topography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Lot size and density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Occupancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Socio-economics and regulatory environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Implementation and management strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Technology assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5Available technologies and case studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Rainwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8Stormwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11Greywater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12Wastewater. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14Summary, recommendations and research needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17Suggested research needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19


AcknowledgementsThe Cooperative Research Centre (CRC) for <strong>Construction</strong> <strong>Innovation</strong>’s <strong>Sustainable</strong> Built Assets Program identifi ed<strong>Sustainable</strong> Subdivisions as one of fi ve key thematic areas of research for 2001–07. This publication <strong>Sustainable</strong><strong>subdivisions</strong>: Review of technologies for integrated water services review by Clare Diaper, Grace Tjandraatmadjaand Steven Kenway and its associated research report results are outcomes from the CRC project ‘<strong>Sustainable</strong><strong>subdivisions</strong> – Integrated water services review’. The project team members are:Project leaderSteven KenwayCSIROResearch contributorsClare DiaperCSIROGrace Tjandraatmadja CSIROMichelle Hennessey Brisbane City CouncilScott Prenzler Brisbane City CouncilStewart Crook Qld Department of Public WorksDelwyn Jones Qld Department of Public WorksRon ApeltQld Department of Public WorksMichael Ryan BrookwaterWarren Steiner BrookwaterSusan CrozierQld HousingWithout the fi nancial and collaborative efforts bringing together industry, government and applied researchers, thisvaluable report could not have been successfully delivered to our industry.Project partnersIndustry Government Researchiv


Abbreviations used in this reviewASR aquifer storage and recoveryBaCC Bayside City Council, MelbourneBCC Brisbane City CouncilCH2 Council House 2GCCC Gold Coast City CouncilIUWM Integrated Urban Water ManagementSEQ South East QueenslandSEW South East Water, MelbourneWSAA Water Services Association of AustraliaWSUD Water Sensitive Urban DesignAbout the Cooperative Research Centre for <strong>Construction</strong> <strong>Innovation</strong>The CRC for <strong>Construction</strong> <strong>Innovation</strong> is a national research, development and implementation centre focused on theneeds of the property, design, construction and facility management sectors. Established in 2001 and headquarteredat Queensland University of Technology as an unincorporated joint venture under the Australian Government’sCooperative Research Program, <strong>Construction</strong> <strong>Innovation</strong> is developing key technologies, tools and managementsystems to improve the effectiveness of the construction industry. <strong>Construction</strong> <strong>Innovation</strong> is a seven-year projectfunded by a Commonwealth grant, and industry, research and other government support. More that 300 individualsand an alliance of 21 leading partner organisations are involved in and support the activities of this CRC.There are three research areas:Program A — Business and Industry DevelopmentProgram B — <strong>Sustainable</strong> Built AssetsProgram C — Delivery and Management of Built Assets.Underpinning these research programs is an Information Communication Technology (ICT) Platform.Each project involves at least two industry partners and two research partners to ensure that collaboration andindustry focus is optimised throughout the research and implementation phases. The complementary blendof industry partners ensures a real-life environment whereby research can be easily tested and results quicklydisseminated.v


IntroductionIntroductionIntegrated Urban Water Management (IUWM) andWater Sensitive Urban Design (WSUD) are two setsof principles often applied in designing and managingwater services in urban areas. The purpose of thisreport is to discuss IUWM technologies availableat the household through to subdivisional level, aswell as identify research gaps associated with thesetechnologies and their adoption.IUWM addresses drinking water, wastewater andstormwater systems while considering the whole watercycle including groundwater, surface water and watervapour. IUWM considers the economic, social andenvironmental benefi ts and issues over the life cycle ofthe water-servicing option. The incorporation of thesethree dimensions has been found to facilitate moresustainable water servicing.WSUD was originally meant to encompass all watercycle issues; however, the design focus has beenprimarily on land use, topography and planningdimensions and the concept now mainly considersstormwater fl ow and quality. Consequently WSUD canbe described as a subset of IUWM. Both IUWM andWSUD incorporate sustainability as they incorporateeconomic, social and environmental dimensions.The fundamental objectives of IUWM are to reducethe need to abstract water from the environmentand maintain environmental fl ows, as well as reducedischarges of contaminant to the environment. Theseobjectives are combined with economic, social andother environmental objectives to provide moresustainable options for water servicing.This review discusses technologies available at thehousehold to suburban level which contribute to IUWMin the form of physical systems, as well as a rangeof water, wastewater and stormwater managementtechnologies which offer alternative approaches toexisting water services. The options are suitable forhousehold, cluster and subdivisional scales and are allpossible technologies that can be used when developingIUWM strategies.In addition to technologies, there are many otheroptions available, such as regulation, fi nancialincentives, education campaigns and participatoryapproaches. These are not assessed in this report,but were identifi ed as complementary options to theavailable technologies and were often infl uential inthe adoption of technologies. Additionally, this reviewdoes not cover all aspects of the process of developingIUWM options, but focuses on technology options thatare currently available and the identifi cation of barriersand issues associated with their implementation.The content of this publication combines a literaturereview of existing alternative technologies in Australiaand an investigation of eight case studies to providea qualitative assessment of the barriers and issuesassociated with technology implementation. It alsocontains the condensed fi ndings of a research report(Diaper, Tjandraatmadja & Kenway 2006) whichprovides detailed information on case studies andbackground literature.The technologies presented are applicable acrossAustralia, but the focus is on South East Queensland(SEQ) refl ecting the partners represented in theCRC for <strong>Construction</strong> <strong>Innovation</strong> for this project.Most data presented in this report covers BrisbaneCity Council (BCC) and the Gold Coast City Council(GCCC) regions as information was readily availablefor these areas. SEQ encompasses many other areasand local government jurisdictions, from Noosa in thenorth through to the NSW border and westwards toToowoomba. This area is currently under severe waterstress.The fi rst section of this publication provides a review ofthe current and historical water usage patterns aroundAustralia, and details strategies and issues particularlyrelevant to SEQ.Factors that may infl uence the selection of alternativewater-servicing approaches are discussed and thebasics of option assessment detailed. Technologiesappropriate for different scales of application are thenprovided, categorised by the water source:• rainwater – water collected from roofs• stormwater – water collected from roofs, roads,pavements and open space• wastewater – water that has been used• blackwater – wastewater from toilet fl ushing• greywater – wastewater from showers, baths,laundry and kitchen.The benefi ts of, and issues concerning, theimplementation of these technical solutions in anintegrated water system are presented using casestudysites. A summary table presents the mainoutcomes of case studies and the literature review, andoutlines potential future projects for understanding andmitigating the barriers to implementation.1


Residential water useWater is a major national and local issue as much of thecountry experiences an extended drought. In January2007, SEQ remains infl uenced by the longest recordeddrought in Australian history (Natural Resources andWater 2006) and most other cities are similarly affected.Climate change has affected all aspects of the water cycleand it challenges current water-management practicesand policy. In addition, predicted population growth andincreased urban housing densities also impact on thewater cycle and are important factors in consideringwater management into the future.Residential water use comprised a substantialcomponent of total urban water use in 2004–2005.Figure 1 shows that residential use accounted for around60% of most Australian capital cities’ total mainssuppliedwater; in Perth, it accounted for 70%. In SEQ,54% of the population lived in BCC and GCCC regionsin 2004, hence a combined usage is used to improvecomparability with other major urban centres. Nonresidentialwater, which is primarily commercial andindustrial water use, constitutes around 20–30%. Around10–15% of water is supplied or used for other purposes,including water losses, fi re-fi ghting and system fl ushing(WSAA 2005).10090% of total water supplied80706050403020100Sydney Melbourne Brisbane andGold CoastPerthResidential water Non-residential water Other water suppliedFigure 1 Usage of mains water in major Australian cities, 2004–2005. (Source: WSAA 2005)Figure 2 shows residential water consumption and population for major Australian cities. Annual consumption percapita and per dwelling in BCC and GCCC and Perth are high when compared with Sydney and Melbourne.3004.234.5Annual residential water consumption(kL/capita/a or kL/property/a)250200150100503.581.47 1.4843.532.521.510.5Population (million)0Sydney Melbourne Brisbane andGold CoastPerth0Consumption per capita Consumption per property Population2Figure 2Residential water consumption and population for major Australian cities (note: Brisbaneand the Gold Coast data are averages for these two closely located areas of SEQ).(Source: WSAA 2005)


Residential water useFigure 3 shows residential per-capita water use between 1999 and 2005 in major Australian urban centres. Theaverage of BCC and GCCC data shows no reduction in usage compared to other cities over the six-year period. Waterusage trends can be infl uenced by many factors, including climate, water restrictions and water use and effi ciencypolicies. Separation of the infl uence of these factors is complex and has not been attempted in this study.150Residential water use (kL/capita/a)12510075SydneyMelbourneBrisbane and Gold CoastPerth387337287237187Daily residential water use (L/capita/day)501998–99 1999–00 2000–01 2001–02 2002–03 2003–04 2004–05137Figure 3Annual per-capita residential water usage for major Australian cities (note: no consumption data for Gold Coast wasavailable for 1998–1999, hence that year was not included in the graph). (Source: WSAA 2005)The four urban centres in Figure 3 are predicted toaccount for over 90% of Australia’s population growthto 2026 (WSAA 2005). In Queensland, the SEQ RegionalPlan (SEQ Offi ce of Urban Management 2005) predictsmedium-range population growth from 2.7 million in2006 to 3.7 million in 2026. At this rate of annual growth,20 000 new residences will be required per year in SEQ. TheSEQ Regional Plan recommends 40% of new dwellings to2016 be infi ll or redevelopment. This percentage fi gure islikely to increase if the number of greenfi eld sites becomingavailable does not keep pace with development.Figure 4 shows the split of residential end uses of mainswater on a per-capita basis for the major urban centresin Australia. This data has been compiled from waterusage data published by the Water Services Associationof Australia (2005) and public documents produced bywater utilities regarding the approximate breakdown ofwater use. The fi gure suggests substantial variation inper-capita water use across Australian cities; however,further analysis would be necessary to validate this.Similar — and at times even higher — variation canoccur within cities and it is important for developmentsin any particular location to have a good understandingof the factors which infl uence use.Water use (kL/capita/a)120100806040Other indoor (e.g. kitchen)Clothes washerToiletShower and bathroomGarden and outdoor20Figure 40Sydney Melbourne Brisbane andGold CoastHousehold water uses for major Australian cities.(Source: WSAA 2005, Sydney Water 2006, BCC 2004)Perth3


SEQ — Current strategies andinitiativesStrategies and initiatives in place to achieve reductionsin water use in SEQ include:••••••mandatory water restrictions on outdoor water useWSUD, rainwater tank rebates, and retrofi tting(including redesign and re-engineering) incentivesrequirements for water recycling and effi cientappliances in new developmentswater recycling targets‘fi t-for-purpose’ strategies for major industrial andcommercial usersprogressive upgrades of capacity in wastewatertreatment facilities.These approaches also support the SEQ Regional WaterSupply Strategy mains water consumption targets of270L/capita/day by 2010 and 230L/capita/day by 2020(Department of Natural Resources and Mines 2006),which are reductions from the 2004 regional average of300L/capita/day (Australian Water Association 2005).The targets should be readily achievable in Brisbane andthe Gold Coast where residential use has been less than270L/capita/day for most of the previous fi ve years.However, other SEQ areas may fi nd these targets harderto achieve if, as the Australian Water Association datasuggests, some have much higher water consumption;for example, residential use in Beaudesert, Caloundra,Cooloola and Noosa at 370L/capita/day.In SEQ, the installation of greywater systems hasrecently been accepted by the State Government, withfi nal approval still resting with local councils. Systemtype and management are important factors to consider,as some uncertainty exists regarding the potentialimpacts of greywater on soils and runoff water quality.Whilst there has been national coverage of stormwateruse, the Stormwater Industry Association Queenslandhas expressed concern that the SEQ Regional Plandid not highlight the resource value of stormwater(Stormwater Industry Association Queensland 2006).The Message from the Minister in the Towards<strong>Sustainable</strong> Housing in Queensland Discussion Paper(Department of Local Government, Planning, Sport andRecreation 2004) suggests the use of water effi cientappliances, rainwater tanks and pressure reductiondevices as potential future options. The introductionof new water-saving measures followed a communityconsultation process of the discussion paper.New measures include the promotion of greywaterand rainwater systems as well as various demandmanagement approaches. These are being implementedthrough the Standard Building Amendment Regulation(No. 1) 2006 which references Rainwater Tanks(Part 25) and <strong>Sustainable</strong> Buildings (Part 29) of theQueensland Development Code.Some local governments in SEQ have a policy thatall new urban developments refl ect WSUD principlesby 2010 (e.g. Brisbane City Council 2005b). Thissound initiative, however, does not specify householdwater consumption targets to be achieved by newdevelopments.Factors affecting technologyselectionThis section describes some of the key factorsinfl uencing the selection of alternative water-servicingapproaches in residential <strong>subdivisions</strong>. All these factorsinfl uence appropriate applications of given technologiesand the viability of potential options. A summary ofassessment techniques is also included.ClimateLocal climate infl uences selection of approaches towater servicing. While average annual rainfall is acritical indicator of available water in a new or existingsubdivision, other factors must also be considered,including the variation in annual, monthly and dailyrainfall and evaporation rates, and the climate’sinfl uence on water use, especially for irrigation.TopographyTopography can dictate plot and infrastructure layout,with graded slopes being the more desirable terrain.Steeper slopes impose more constraints on style andform of construction.Steeper slopes lead to greater surface fl ows and loadswhich can increase sewage pumping and costs. Onthe other hand, slope can be exploited to allow gravityto assist in collection and supply of natural water orwastewater fl ows.Lot size and densityFor most developments, lot size is strongly infl uencedby the fi nancial viability of the development; however,changing demographics, dwelling types, consumerexpectations and affordability are also infl uential. Lotsize affects selection of water-servicing strategies. Forexample:• A large irrigation area is required to distributeand absorb treated wastewater for many on-sitewastewater treatments.• Rainwater tanks and stormwater collection systemsmay need large areas to capture and store watervolumes required for reliable supply.Lot size and density also affect the capacity for largescalemanagement of stormwater and wastewater in wetmonths suffi cient to cover supply in dry periods.4


Factors affecting technology selectionOccupancyHousehold occupancy patterns infl uence the volumes ofpotable water consumed and wastewater produced. Keyfactors when selecting water-servicing options are:• Per-capita mains water consumption andwastewater generation decrease with increasingoccupancy levels.• Trends are for lower occupancy per dwelling andhigher dwelling density per land area. Averagehousehold size in SEQ of 2.6 persons in 2001 isdeclining to estimates of 2.45 by 2011, and 2.29 by2026 (SEQ Offi ce of Urban Management 2005).Socio-economics and regulatory environmentOther factors which can infl uence the adoption ofparticular technologies include socio-economic andregulatory infl uences. For example, the perceivedbenefi ts of particular technologies, the direct costs andongoing costs relative to centrally supplied water, thelevel of government subsidies and legislative ease ofimplementation, can all affect technology uptake.Implementation and management strategyManagement strategies adopted infl uence theprobability of successful implementation of moresustainable water services. Currently, stormwater,wastewater and mains water supply are largelyseparately planned. This acts as a barrier toimplementing integrated water services (Mitchell 2004).Mitchell found successful projects often involve a highlevel of public involvement and strong partnerships,alliances or project champions providing impetusto see the project through to completion. Hence,implementation of alternative water services requiresattention to existing, as well as new, managementstrategies.Technology assessmentThere are a wide range of alternative water-servicingtechnologies available, including systems for thecollection and use of rainwater and stormwater, andthe treatment and use of greywater and wastewater.The task of assessing which type of technology isappropriate is a complex task and is not the focus ofthis report. The suitability of any particular technologywill be infl uenced by a number of factors includingthe scale of application (e.g. from household tosubdivisional level) as well as the performance requiredand operational and maintenance needs. This reportfocuses on the benefi ts of the technology in terms ofthe urban water cycle and on operational, practical andassociated issues associated with implementation.There are a number of methods which can be used togive a thorough and detailed assessment of the differenttechnologies and aid in technology selection. Tools thathave been used previously for assessment of optionsinclude:•••••water balance analysiscontaminant balance analysislife cycle costing (LCC)life cycle assessment (LCA) covering energy,materials and emissionsrisk assessment and management.Water and contaminant balance assessment oftechnologies should consider impacts on the entireurban water cycle, particularly with regard to waterfl ows and quality. This sort of assessment can evaluatethe ability of a technology to meet IUWM objectives,such as reduction in mains water usage or return ofsurface fl ows to pre-development conditions.LCC is a process to determine the sum of all thefi nancial costs associated with a technology, includingacquisition, installation, operation, maintenance,refurbishment and disposal.LCA is an objective process to evaluate theenvironmental burdens associated with a product,process or activity from ‘cradle to grave’. This is doneby identifying energy and materials used and wastesreleased to the environment.There are many risk assessment and managementprocesses which are applied to urban water systems.The assessment of health, environmental, social,institutional and political risks should also be includedin an IUWM process.5


Available technologies and casestudiesThe literature reviewed (Radcliffe 2004; AustralianWater Conservation and Reuse Research Program2004; Landcom 2006; Diaper et al. 2006) and the casestudies examined for this project cover a large range ofurban residential and commercial development watermanagementoptions and include both new build andretrofi t case-study sites. The eight case-study siteswere:••••••••Pimpama Coomera — SEQ, new build, residentialsubdivisionPayne Road — SEQ, new build, small residentialsubdivisionThe Currumbin Ecovillage — SEQ, new build,residential subdivisionCH2 — Melbourne, new build, offi cesSouth East Water (SEW) and Bayside City Council(BaCC) — Melbourne, retrofi t, residentialAtherton Gardens — Melbourne, retrofi t, highdensity housing<strong>Sustainable</strong> House — New South Wales, retrofi t,single residential60L — Melbourne, retrofi t, offi cesSome sites have an overall sustainability themeencompassing energy, material and operating costs,while others focus only on water services (Table 1).Eight case-study sites were selected for furtherstudy from a full list of case-study sites (Diaper et al.2006), with selection based on feedback from projectstakeholders, BCC, Brookwater and QueenslandGovernment departments and the following criteria:•••••••appropriate to individual dwelling through tocomplete <strong>subdivisions</strong>applicable to retrofi tting or re-engineering ofexisting housing stockdemonstrates alternative water-servicingtechnologiesdemonstrates transitioning of existing infrastructureprovides detail of fi nancial arrangements for projectimplementationimplemented in social housing stockimplemented in inner urban areas or commercialpremises.Some sites outside of SEQ were included todemonstrate valuable lessons and approachesapplicable to SEQ.The following section describes different technologiesfor rainwater, stormwater, greywater and wastewatercollection, treatment and use. The primary benefi tsto the urban water cycle and the potential issues andbarriers to implementation of each technology typeare described, incorporating information gained fromrelevant case studies. A review of strategies andtechnologies implemented in SEQ is also provided.6


Available technologies and case studiesTable 1Overview of case-study sitesCase-studysitePimpamaCoomeraPayne RoadThe CurrumbinEcovillageCH2Raintanks Stormwater Greywater WastewaterHouseholdHousehold andcommunalHouseholdRooftopcollection forbuilding useClusterWSUD, ponds forirrigationCommunalcollection andWSUD for run-offtreatmentWSUDNot applicableDischarged withwastewaterHousehold forgarden irrigationDischarged withwastewaterDischarged withwastewaterSubdivision reducedinfi ltration gravity sewersand regional wastewatertreatment to Class A andrecycling via third pipefor non-potable useCommunal collectionand timed discharge intosewerMix of cluster andhouseholdOn-site treatment andsewer mining for nonpotableuseSEW and BaCC Household Current system Current system Current systemAthertonGardens<strong>Sustainable</strong>HouseRooftop inone buildingcollectionfor gardenirrigationHouseholdWSUD treatmentprior to dischargeHouseholdOn-site miniwetland60L Communal Not applicableCommunallaundry greywatertreatment foruse in gardenirrigationDischarged withwastewaterDischarged withwastewaterDischarged to sewerHousehold on-sitetreatment for nonpotableuseCommunal collection andon-site treatmentStatus andresearchreportreferenceUnderdevelopmentSection 4.1UnderdevelopmentSection 4.2UnderdevelopmentSection 4.3CompletedSection 4.4UnderwaySection 4.5CompletedSection 4.6CompletedSection 4.7CompletedSection 4.87


RainwaterThe Australian Bureau of Statistics (2005) reports that17% of homes have rainwater tanks installed for allhousehold water end uses. However, most of thesetanks are installed in rural areas. In urban areas, theaesthetic form and physical size of a tank are criticalfactors for selection, rather than capacity to providereliable supply. The many designs in the market range insize, shape, fabrication material, collection system andtreatment technology to be appropriate for various lotsizes, dwelling types and end-user needs.Rainwater systems involve collection, storage,treatment and distribution technologies. The three maintypes of collection systems are:• dry systems (the most common type) — all pipesare above ground• wet systems — collection pipes are buried toreduce aesthetic impact and pipes contain aresidual volume of water• siphonic systems — the collection system isdesigned to maximise pipe fl ow rates usingsiphonic full bore fl ow.Collection systems employ gutter guards, fi rstflush diverters and inlet fi lters to reduce ingress ofcontaminants such as leaves, animal faecal matterand airborne pollutants. Gardner et al. (2004) foundfi rst-fl ush devices reduced rainwater tank contaminantlevels at the cost of collection effi ciency. Althoughthe use of fi rst-fl ush devices is frequently advocatedby manufacturers and in guidance notes, statisticallyrelevant data showing their relative contaminantremovaleffi ciency or improvement in stored waterquality is lacking.Distribution of rainwater is usually via a pump, althoughin certain situations, end uses can be gravity fed. Ifmains water is used as a back-up supply, it is notrecommended to top up the tank, as the mains waterloses potential energy when supplied to the tank andthen has to be repumped to required end uses(Gardner et al. 2006). An automatic diverter device, inwhich mains water pressure is used when mains waterback-up is required, is more effi cient in terms of energyuse.Treatment of rainwater depends on the intended enduse and three main types are used: fi ltration, thermaldisinfection and ultraviolet (UV) treatment. Filtrationprovides a barrier to micro-organisms and both microandultra-fi ltration are used. Thermal disinfection usingthe hot water service is currently being investigated,and results have shown that bacteria do die off attemperatures relevant to domestic hot water systems.None of the treatment processes provide residualdisinfection, and all have associated maintenance andreplacement requirements.Householder awareness of what is in their rainwatertank is important so that usage can be adjustedaccordingly and also so they know when mains waterback-up is being used. A number of innovative fl oatsystems are available to monitor tank water level, andsome can be retrofi tted to existing tanks.Mains water savings due to the installation of raintankswill be dependent primarily on the volume and timingof runoff into and out of the raintank. This meansthat factors affecting the savings will include: climate,collection area, tank size, water usage, irrigationrequirements and end uses of the rainwater.Rainwater collection system — 60L8


Available technologies and case studiesModelling studies have shown that, dependent onrainfall patterns, improved water savings can beachieved when rainwater is supplied to non-seasonaluses, such as toilet, laundry and bathroom, ratherthan seasonal uses such as irrigation (Institute of<strong>Sustainable</strong> Water Resources 2006). Other studies haveshown that additional savings are possible for higherdensity development for non-seasonal end uses (Gray2004). Additional benefi ts of rainwater tank installationare the reduced energy requirement compared to largescalewater resource options such as desalination,reduced stormwater fl ows and, if designed accordingly,reduced mains water peak fl ows (Marsden JacobAssociates 2007).Individual household raintanks are an integral partof rural Australia, but there are few studies whichthoroughly assess the effectiveness and performanceof these systems in urban areas. Two case studieswhere this is being done are the <strong>Sustainable</strong> Housein Sydney (Diaper et al. 2006, Section 4.3) and PayneRoad in Brisbane (Gardner et al. 2006; Diaper et al.2006, Section 4.6). At the <strong>Sustainable</strong> House, rainwateris collected from the roof via enclosed gutters forremoval of leaves, a sloping mesh trap at the downpipe,and a fi rst-fl ush diverter. There is a sump for sedimentremoval before the 9.5kL concrete raintank. Rainwateris used as drinking water, in the shower and as coldwater for the washing machine, with an overfl ow into amini-wetland.Key learning Established buildings and sites imposelimitations. For example, the roof areaimposes limitations on the amount ofwater which can be collected.At Payne Road, 18kL to 22kL rainwater tanks areinstalled for each household. The collected water istreated by activated carbon fi lters (1µm) and UV beforeuse in all household applications. Excess rainwater isdiverted to communal tanks located at the bottom ofthe development. These communal tanks are used toprovide fi re-fi ghting fl ows.Key learning Mains water top-up to a rainwater tankrequires repumping of mains water supplyto provide household demands.Two larger-scale developments with raintanks installedat individual dwellings are Pimpama Coomera (Diaperet al. 2006, Section 4.1) and the Currumbin Ecovillage(Diaper et al. 2006, Section 4.7). In all PimpamaCoomera <strong>subdivisions</strong>, 3kL and 5kL rainwater tanks arefi tted to all households for use in laundries, bathroomsand hot water systems. At the Currumbin Ecovillage,a 110ha subdivision currently under development,rainwater collection will be at household level with arange of tank sizes depending on house size. The tankswill supply all uses in the home, including drinking, aswell as a 5kL fi refi ghting requirement. The treatmentof rainwater prior to use will be at the discretion of thehouseholder. All dwellings will have 3A- or 4A-ratedappliances. Restrictor valves fi tted on rainwater supplyto the house provide feedback to inform occupants oflow water levels.Key learning Calculation of tank sizing is dependent onend uses.Rainwater collection system — Payne Road9


Case-study sites where rainwater is collected from anumber of roofs for communal use are Payne Road(Gardner et al. 2006), Atherton Gardens, CH2 and 60L.At Payne Road, an urban residential development,a combination of household tanks and communaltanks is used to satisfy both domestic water demandsand fi refi ghting fl ows. Although there are distinctmaintenance and operational responsibilities for thehouseholder at single-house scale, at cluster scale theboundaries for these responsibilities are not so clearlydefi ned, and this may be an issue in the successfulimplementation of rainwater systems. In the caseof CH2 and 60L, the management of the buildinginfrastructure and the water resource is undertaken by acentral body.Key learning Different scales of collection can beincorporated into one development.In the SEW and BaCC study, 60% of respondents wereprepared to use rainwater for showers, laundry, toiletfl ushing, car washing and garden watering, but only 5%had installed systems, stating ‘too expensive’ or ‘toodiffi cult to organise’ as reasons.Key learning The costs and practicalities of retrofi ttingrainwater tanks need to be considered.Key issuesFrom the literature review and case-study analysis,a number of key issues associated with theimplementation of rainwater tanks are:• Water quantity and quality need to be consideredin the design of rainwater collection, storage anddistribution systems.• Water savings and reliability of supply depend onclimate, storage volume, collection area and enduses.• The design of back-up supply should considerenergy balance and controls to ensure householderawareness of back-up supply use.• Additional energy requirements for raintanks willdepend on the amount of pumping and treatmentmethods.• Maintenance and operational responsibilities ofcluster systems are not well defi ned.Rainwater collection system — Atherton Gardens10


Available technologies and case studiesStormwaterStormwater is the surface runoff from all perviousand impervious areas and will have a different qualitycompared to rainwater. Stormwater is collected viadrainage systems and generally diverted to stormwatermains that are maintained by municipal councils.There are few stormwater technologies specifi cally forhousehold-scale application, except permeable pavingand the reduction of impervious paved areas to reducestormwater fl ows.Recently, use of stormwater as a large-scale supplysource has gained media attention throughout Australia(Urban Stormwater Initiative Executive Group 2004;State Government of Victoria 2004; StormwaterIndustry Association Queensland 2006). Treatment andstorage of rainwater and stormwater are most oftenaddressed at subdivisional level, and at this scale anumber of approaches apply to collection, treatment,storage and redistribution. An inventory and review ofAustralian practices in integrated stormwater treatmentand harvesting found that stormwater reuse was largelyrestricted to smaller-scale sites and that treatment isstill based on systems designed for environmentalprotection, not domestic use (Hatt et al. 2004). Thisis a concerning trend, as the water quality may notbe suitable for reuse. Further work is required todevelop reliable, robust techniques and technologiesto provide water of a quality suitable for drinking watersubstitution.Many available technical documents and guidelinesprovide detailed design guidelines and strategies forimplementing stormwater systems for environmentalprotection (City of Melbourne 2004; Wong 2006;Brisbane City Council 2005a). To make stormwatersuitable for use as a substitute for municipal potablewater supply, technologies and techniques used need todeliver higher and more consistent levels of treatment.A recent document providing technical guidance forstormwater treatment and harvesting (Institute for<strong>Sustainable</strong> Water Resources 2006) suggests UV as apreferred disinfection technique, non-seasonal end usesto minimise storage requirements and no requirementfor closed storages for minimisation of evaporation. Thereport also identifi ed stormwater harvesting systemsneed to be robust and to provide a buffer against qualityand quantity variability.At the scale of groups of houses or <strong>subdivisions</strong>,rainwater (as opposed to stormwater) collection,storage and treatment tend to be in underground tanks,as space is often limited in urban areas. Sub-surfacetanks have the advantages of reducing light penetration,stabilising water temperatures and reducing evaporationlosses. However, care is needed in selecting locationand design of access to avoid contaminant ingress,while still allowing easy access for maintenance.Innovative designs for sub-surface storage also providesome stormwater treatment, and systems have beenused in single dwellings, residential aged-care facilities,parks and schools (Atlantis Water Management 2007).A stormwater collection and treatment techniqueappropriate to the cluster or subdivisional scale whichcan overcome the storage requirement, is aquiferstorage and recovery (ASR). The use of this methodis dependent on local geology and accessibility of theaquifer. Examples of test sites for stormwater ASR canbe found in South Australia (Dillon et al. 2006) and NewSouth Wales (Argue & Argue 1998), and opportunitieshave been explored in other states. In addition to thegeneral advantages of stormwater use, ASR also has thebenefi ts of potential reduction in groundwater salinity,reduced storage costs and storage which does not takeup land area. ASR can also be used for the storage ofwastewater.The Atherton Gardens high-density residentialdevelopment in Melbourne, consists of an estate withfour high-rise towers. The Department of Housing sitehas four water systems retrofi tted: two stormwater, onegreywater and one rainwater collection system. Thestormwater systems recover stormwater for passivelandscape irrigation and treat it before discharge intothe stormwater drain reducing contaminant loads. Thegreywater system collects laundry greywater and, aftercoarse fi ltering, fl ows to a landscape feature wetland.The rainwater system collects from the roof of one ofthe towers to be used for garden irrigation. Extensivesurveying of the site was required to identify thepossibilities and potential design constraints.Key learning The process of retrofi tting technologiesrequires a large amount of planning andsurveying.CH2 and 60L are Melbourne offi ce buildings, the formera new build infi ll and the latter a retrofi t of a commercialbuilding (i.e. the facade of the original building waspreserved, but the rest of the building was redesignedand reconstructed). At 60L, two large rainwater storagetanks are located inside the building and providewater for toilets and washbasins. The tanks are opento occupants’ view and are very much an educationalfeature of the site. At CH2, water is collected from theroof of the offi ce building in one 20kL tank and used forpotable applications. Wastewater from the building istreated and mixed with treated wastewater mined froma sewer pipe and used for cooling towers, irrigationof plants, toilet fl ushing, Melbourne Council’s streetsweepingmachines and other external uses. Bothsites use traditional cylindrical and rectangular storagetanks for storage of the collected water. In the Atherton11


Gardens housing development the water featurescontribute to improving the amenity of communalareas. Associated benefi ts, such as greater use byfamilies, larger number of people using the gardens asa throughfare and reduction in the number of vandalismincidents, have been highlighted by the projectmanagers and are currently under study.Key learning Alternative water-servicing approachescan be an educational feature of a buildingor a community amenity.Key issuesA number of key issues associated with theimplementation of stormwater collection, storage,treatment and use are:• Robust and reliable methods of treatment needto be developed in order to provide stormwatersuitable for mains water substitution.• Large storage volumes for stormwater may berequired when used for seasonal end uses.• Space limitations in existing urban areas maylimit the feasibility of stormwater collection in thisapplication.• Retrofi tting of stormwater systems requiresadditional planning and surveying compared togreenfi eld implementation.• There are currently no legislative guidelines for useof treated stormwater.Greywater system — Ecocare diverterGreywaterThe main sources of greywater are the bathroom,laundry and kitchen. Most greywater systems aredesigned to collect and treat greywater from thebathroom and laundry only, as kitchen wastewaterusually contains higher concentrations of grosscontaminants and fats, oils and greases.Greywater does offer the advantage over rainwatersystems of a continuous supply available during dryperiods. The potential water savings associated withgreywater treatment and use are well documented andwill be primarily dependent on end use (Gardner &Millar 2003; WAWA 1993; Priest et al. 2003; Diaper etal. 2003).Modelling data suggests that more than a 20%saving can be made with a 1000L tank collecting bothbathroom and laundry greywater and supplying bothgarden uses and toilet fl ushing (Gray 2004).The two basic types of greywater system are the directdiversion systems and the collection, treatment, storageand distribution systems which produce higher qualitywater. Direct diversion systems are available for subsurfaceirrigation and toilet fl ushing, while greywatertreatment systems can be used for gardens, toilets andpotentially laundries.Consideration of greywater quality is important inassessing potential uses for different source streams.Greywater can contain:••••human pathogensnutrients such as phosphorus and nitrogendissolved salts such as sodium and sulfatesbiodegradable organics.Greywater components can have detrimentalenvironmental impacts on groundwater and soilstructure.Many greywater recycling systems are available andcost depends on house design, space availability andpiping requirements. Systems range from simplefi ltration and diversion systems to complex treatmenttrains (Diaper et al. 2006). The different systemsprovide different greywater qualities, some meetingVictorian and New South Wales guidelines for recycledwastewater. Although most systems are suitable forretrofi tting or re-engineering, the need to separategreywater from blackwater may limit application inexisting houses built on slabs. The prevalence ofQueenslander-style houses in existing housing stock inSEQ makes collection and reuse of individual householdwastewater streams more feasible due to ease ofaccess to pipework.Key learning Housing style can improve the feasibilityof greywater use.12


Available technologies and case studiesPenetration of household-scale greywater technologiescan increase community awareness and understandingof broader water resource issues (AlternativeTechnology Association, 2005). Also, for singledwellings, greywater use has broad communityacceptance. While studies have gauged acceptance ofwastewater reuse at larger scales (Po et al. 2003; Poet al. 2005; Hurlimann & McKay 2003, 2004), nonereviewed have examined public perceptions of largescalegreywater reuse.Key learning Household technologies can provideincreased community understanding ofwater resource issues.At Payne Road, greywater from individual householdsis treated via a Biolytix system and the treated effl uentis used for sub-surface garden irrigation. Irrigationvolumes are controlled by soil moisture sensors andsolenoid valves which divert greywater to the sewerif the soil becomes saturated. All unused wastewateris collected to common tanks in the subdivision anddischarged to the sewer system at non-peak hours.Key learning Storage and use of greywater can reducesewer peak fl ows.Similarly to the fi nding for raintanks, the SEW and BaCCsurvey showed a high percentage, 60%, of respondentswere prepared to use greywater for toilet fl ushing, carwashing and garden watering, but only around 5% hadinstalled systems.Greywater system — Pontos AquacycleKey issuesFrom the literature review and case-study sites, anumber of key issues with the implementation ofgreywater collection, storage, treatment and use wereidentifi ed:• Components of household products found ingreywater may affect the environment through soilstructural degradation, increased soil pH and poorplant growth.• There are lengthy approval processes when newtechniques or technologies are used and there is nonational guideline for greywater system testing.• Separation of greywater from blackwater mayrequire extensive plumbing alterations, especially inretrofi t or re-engineering situations.• There is a lack of information on garden design andwatering requirements when greywater is used forirrigation.• High-technology treatments may have highembodied and operating energy requirements andthe capital costs may be high.• The maintenance and management of householdand multi-dwelling greywater systems needs to beconsidered.Greywater system — New Water13


WastewaterWastewater is all the used water leaving a dwellingand can be split into greywater (discussed previously)and blackwater, with blackwater carrying toilet wastes.A large proportion of wastewater is water, with only1–2% of the total mass as organic and inorganicsuspended solids. In domestic wastewater, organicmatter comprises carbohydrates, fats and proteins, andinorganic matter comprises dirt, grit, salts, metals andother contaminants. Wastewater also contains humanfaeces, a major source of pathogens in such water.In Australia, on-site wastewater management is presentmostly in unsewered areas to ensure sanitation. Onsitewastewater management occurs by either reducingvolume of water used for transport of waste or by onsitetreatment and reuse of wastewater. Reduction ofwater volume measures (demand management options)have a direct impact on the wastewater producedand, at single household scale, options for reducedwastewater production include:• elimination or reduction of water used for solidtransport, such as dry toilets and water-savingappliances (e.g. low-fl ush toilets)• separation and treatment of solid and liquidfractions, such as urine-separating toilets.Compared to large-scale wastewater treatment, thereare some distinct advantages with treating wastewaterat the household scale. The wastewater tends to havea lower level of persistent contaminants and pollutantsfrom stormwater runoff (hydrocarbon residues), and sosimpler treatment methods can be employed.At a household level around Australia, the treatmentand reuse of wastewater has been implemented in anumber of sites (e.g. <strong>Sustainable</strong> House). Due to thehigh faecal micro-organism concentration and thuspotential pathogen presence, there is a need to preventhuman health risks and environmental contamination.Thus, there are added challenges when consideringwastewater use compared to greywater and rainwater.Effl uent is reused in non-potable applications includinggarden irrigation and, after disinfection, for toiletfl ushing. Sludge is usually removed by a contractor ordisposed of to sewer (e.g. CH2).A potential barrier to implementation of on-sitewastewater systems is the minimal information andguidance on system use provided to householders.Research and proof of effectiveness of a system isoften the responsibility of the individual interested insetting up the system. Consequently, only committedand determined homeowners have adopted suchtechnology.14Geolink (2005) and Landcom (2004) have reviewed therange of advanced wastewater treatment technologiesavailable for on-site treatment. At the cluster orsubdivisional scale, collection systems vary from theuse of vacuum and low-pressure sewerage with lowdiameterfl exible pipes and shallow burial depths,through to ‘smart pipes’ of fl exible material with fusedjoints and inspection points rather than manholes.Selection of source water type depends on waterbalance, end-use application and regulatoryrequirements. Technologies for wastewater treatmentand recycling can be based on biological, chemical andphysical processes, or combinations of these. Someare appropriate for both greywater and wastewatertreatment. Appropriate scale, end uses, physicalfootprint, and capital and operating costs also needto be considered (Landcom 2004). Wastewater andgreywater can be treated to many different qualitiesdetermined by intended uses, such as irrigation ofpublic places or indoor non-potable uses. Generally,effl uent for household supply must be treated to a highClass A standard.At a cluster level, key features of wastewatermanagement are:••••individual household collectiona shared treatment facilitymanagement by body corporate, council orhouseholder associationmaintenance conducted via a service contract withthe treatment technology provider or operator.Such systems remove the onus of maintenance fromindividual householders and allow the governingauthority to exert a greater degree of control on upkeepof the infrastructure system. Also, benefi ts are generallyachieved through economies of scale, with treatmentfacilities shared across multiple dwellings.In the eight case studies examined, wastewatertreatment and use options range from single-housesystems at the <strong>Sustainable</strong> House and Payne Road,through medium-scale cluster options at the CurrumbinEcovillage, CH2 and 60L, to large-scale treatment anddual reticulation of supply of treated wastewater atPimpama Coomera.All wastewater at the <strong>Sustainable</strong> House is collectedinto a concrete tank to which food scraps are alsoadded. The tank contains three fi lter beds of sand andgeofabric with worms and other organisms. The effl uentis disinfected via a solar-powered UV system as it exitsthe tank and is used for non-potable applications in thehouse, such as toilet fl ushing, washing machine hotwater and garden irrigation.At the cluster scale, wastewater at the CurrumbinEcovillage will be collected from the majority ofhouseholds and treated by an Orenco AdvanTex textile


Available technologies and case studiesfi lter coupled to a Memcor micro-fi ltration system.Polyethylene pipes are used for all wastewater andwater supply transport because the developers did notwant to use PVC. The recycled water will be of Class Aquality and will be recirculated to the households fortoilet fl ushing, laundry use and garden irrigation.At 60L and CH2, two different wastewater treatmentapproaches are used in addition to the rainwater andstormwater systems already mentioned. In 60L, allwastewater from the site is collected to a central pointand treated through a biological treatment processcoupled to membrane treatment. Effl uent from theplant will be used for fl ushing toilet pans and irrigatinga 135m 2 rooftop garden. Excess recycled water will bedirected to a water feature in the atrium that containsaquatic plants feeding on residual nutrients, beforebeing discharged to sewer. At CH2, wastewater from thebuilding is collected and supplemented with wastewaterextracted from the sewer. This combined stream istreated by a membrane water reuse plant with ultrafiltration and reverse osmosis process stages. Thetreated blackwater and greywater are used for supplyof non-potable water for plant irrigation, cooling, toiletfl ushing, street washing and open spaces, uses thatcurrently demand 72% of water use. In CH2 and 60L,the minimisation of odour and noise pollution wasconsidered in the selection of the site and design of thetreatment plant. The plant in CH2 is located in the subbasementand the plant at 60L is located at the back ofthe building. Both original treatment systems in 60L andCH2 were upgraded after the commissioning period,as the original systems were not operating optimallywith the wastewater collected. The wastewater was ofdifferent strength to conventional domestic wastewaterfor which the systems were designed, as water useactivities in commercial buildings are not the same asresidential uses.Key learning When designing wastewater treatmentsystems, allow for changes in wastewaterfl ows and concentrations due to increasedwater effi ciency.Key learning Consider noise and odour when siting onsitewastewater treatment plant.Key learning Allow additional time in the projectschedule for verifi cation of innovativewastewater treatment systems.The Currumbin Ecovillage and the 60L building areexamples of sites where the owners and tenantsare required to abide by body corporate rules formanagement of the alternative water-servicing system.At a larger scale, Pimpama Coomera is a fast-growinggreenfi eld development area with a mix of residential,commercial and industrial use in a water-constrainedregion. To allow the development of the region, thelocal council (Gold Coast City Council), in consultationwith other stakeholders, conducted an extensive studyof the area and developed a masterplan and strategyfor sustainable development in the region. The strategyinvolves developing an institutional framework thatfacilitates the implementation and uptake of integratedwater-management services. This will be done throughrevision of council policies, regulations and approvalschemes, and the provision of infrastructure, such aswastewater collection and treatment plants, aquiferstorage, and a dual-pipe scheme for provision oftreated wastewater for toilet fl ushing and externaluses. While the wastewater treatment plant is notyet commissioned, the necessary infrastructure forproviding gardens and toilets with recycled water is inplace.Key issuesA number of key issues were identifi ed with theimplementation of wastewater collection, treatment anduse. Some of these issues are similar to those observedfor greywater systems and are as follows:• Current wastewater operation, maintenance andmanagement arrangements are not geared fordecentralised systems. No current systems are inplace to ensure compliance and enforcement ofproper maintenance of on-site wastewater systemsand current approval processes can be complex.• Adequate treatment is needed to safeguardresidents’ health.• Chemical requirements and embodied andoperating energy for treatment technologies need tobe considered.• Changes in wastewater quality and biosolidsmanagement need to be considered during thedesign of wastewater treatment systems.• The maintenance and management responsibilitiesof household and multi-dwelling wastewatersystems need to be considered.• Knowledge and understanding of the interactionsbetween the built environment, specifi c site aspectsand the wastewater technology is necessary.15


Summary, recommendations andresearch needsSummaryImproved planning and management of water inAustralia is essential to ensure reliability of waterservices and to support the continued growth of ourcities. Drought, population growth and infl uencesrelated to climate change are increasingly affectingexisting water stocks. At the time of writing, manyAustralian cities are under water restrictions, with SEQfacing unprecedented regional level 5 restrictions. SEQis under further pressure because of high per-capita andhousehold water use and a high projected populationgrowth.Many water issues are being addressed throughstate and federal government initiatives. However,this review argues that further attention is required atthe subdivisional and individual household scale toensure the most effi cient solutions are identifi ed andappropriate technologies are adopted. This reviewfocuses on currently available technologies, whilerecognising that the economics, social acceptabilityand impact of planning processes also signifi cantlyinfl uence the uptake of any particular technology.Alternative water-servicing initiatives have beenimplemented around Australia at scales rangingfrom single household through clusters to larger<strong>subdivisions</strong>. Experiences from case studies havehelped gain valuable knowledge for future schemes.Water conservation initiatives, such as low wateruseappliances, are essential for reducing waterconsumption. The installation of water-effi cientappliances and demand management were common tomost case studies. Additional savings can be achievedwith measures such as substitution of mains water withwater from other sources for non-potable applications.This review found a wide range of integrated watertechnologies being used or under development at thehousehold through to sub-divisional scale. While thetechnologies themselves are relatively well understood,the integration of the technologies and impacts on othersystems is less clear. Selecting the most appropriatesystems depends on many site-specifi c factors. Tofully reap the benefi ts of implementing alternativetechnologies, clear understanding is needed of:•••16proposed uses of the water and the qualitynecessary for each usedesign area or system requirementstechnology or project characteristics andlimitations.Most case studies required improved householderunderstanding and involvement in their water-usebehaviour compared to traditional systems. Additionalinvestment in education and information disseminationto householders, council offi cers, regulatory bodies,developers, water providers and the broader communityappears warranted.Further identifi cation of barriers to adoption needs to beundertaken to support existing educational programs.This is particularly important as other studies havefound that despite high community knowledge aboutwater-saving devices, there have been low rates ofuptake of water-saving systems such as greywateruse. For example, costs, home ownership versus rentalstatus, perceived poor performance, and diffi culty inorganising installation all hinder technology uptake(Clarke & Brown 2006).Increased uptake of alternative systems requiresclear guidelines for the selection, design, installationand operation of alternative systems. Simplifi cationof regulatory and approvals requirements is alsonecessary. This applies at the single household aswell as larger development scale. For example, thewastewater system for the case-study site 60L is 5kLin size. This was not big enough to require approval ofthe Environment Protection Authority of Victoria, whichmeant that, despite the project manager’s efforts toengage local water authorities and council offi cers in theselection process, it was diffi cult to identify regulatoryrequirements and appropriate water quality objectives.Many technologies are currently being tested atdemonstration sites and implemented in small- tolarge-scale developments. New applications and usesfor existing technologies are also evolving as newissues and site characteristics are presented. Whilethe knowledge base is growing as more schemes areimplemented, there is still a lack of understanding ofrisks involved in many applications and both industryand regulators are unfamiliar with many of the newsystems. Technology issues identifi ed in this studyinclude:•••••selecting appropriate technologies to treathigher-concentration waste streams produced byhousehold and subdivisional systems which areincreasingly water effi cientconsidering downstream (off-site) impacts ofthe alternative water-servicing approach on,for example, sewage transport and treatmentinfrastructureconsidering chemical and energy use of systemsconsidering biosolids production and managementin the initial design of on-site wastewatermanagement systemsthat the necessary infrastructure is not availablefor technology application in existing houses(brownfi eld).


Summary, recommendations and research needsFollowing from the last point, future thinking in termsof other infrastructure to allow fl exibility in design isrequired. For example, greywater reuse as an optionmay currently be limited due to the inability to separatethis water from wastewater. Source separation innew build houses would allow fl exibility in futureapproaches.In the retrofi t or redesign of existing properties,a number of specifi c issues were identifi ed. Fullunderstanding of the existing system is required priorto the development of alternative water-servicingapproaches, and the incorporation of existinginfrastructure in the design may help to reduce costsand civil works.Technologies can be applied at a range of scalesfrom single house to <strong>subdivisions</strong>. Consideration ofintegrated approaches can have additional benefi ts.For example, communal stormwater tanks at PayneRoad eliminate the need for water mains designedfor fi re fl ows. Correspondingly, pumping and treatingwastewater from the sewer main at the CH2 site allowedother building water requirements to be met.All innovative approaches require a learning periodand this applies to development and implementation ofalternative water-servicing systems. This is particularlybecause there are no universal solutions, only moreappropriate ones for particular situations.RecommendationsIt is recommended that a strategy be developedto outline how government, the private sector andthe community could work to improve the uptakeof alternative and effi cient water technologies. As acomponent of this strategy, the following elementsare recommended for development by the appropriatefederal, state and local government agencies or waterservice providers:1. Further work regarding practical aspects ofincorporating integrated water system technologiesand managing the associated risks. For exampleguidance is needed in relation to treating waterto acceptable standards to meet technical, health,environmental and safety criteria.2. Development of educational and training materialsto encourage continued participation of residents.3. Development of guidelines for various aspectsof management, including planning, design,construction and operation, to give improvedcertainty that particular schemes meet legislativerequirements and standards.Suggested research to support these needs and relatedaspects are described below.Suggested research needsAt the request of the <strong>Construction</strong> <strong>Innovation</strong> ProjectSteering Committee, the authors have nominatedpotential stakeholders or research initiators who couldhelp address some of the issues and knowledge gapsidentifi ed by this study.Knowledge gaps applicable to all scales of developmentwere found in the case-study sites investigated and aredescribed in full in the research report (Diaper et al.2006). Table 2 summarises knowledge gaps which wereidentifi ed as high priority or high impact by the authors,together with suggested research initiators.17


Table 2Suggested research needs and initiatorsSuggested research needsMonitor and assess existing alternative systems and compare their actualperformance to predicted performance prior to implementation. Identifyreasons for any sub-optimal performance.Quantify additional benefi ts of alternative systems (such as reducedenergy and materials usage, and system resilience and householderwellbeing) by detailed lifecycle costing, analysis and monitoring. Alsoquantify associated benefi ts from externalities over LCA.Understand the impact of greywater (treated or untreated) on theenvironment.Improve garden irrigation technologies and practices, including byimproved sensing (climate, soil, water use), by understanding thebehaviour of users (including plant selection and needs), and byapplication of effi cient autonomous and remotely managed systems.Develop options and design criteria for stormwater harvesting for variousresidential uses.Assess the potential impacts of alternative water-servicing approaches onexisting infrastructure and transitioning strategies, including how thesestrategies can be built into longer-term infrastructure masterplans.Investigate alternative funding sources and economic incentives anddisincentives (such as rebates, headworks charges and planningobstacles) for implementation of alternative water-servicing approaches.Review legislative and planning process impacts on adoption of integratedwater-service options with particular focus on how the multi-disciplinesnecessary to deliver water services can be streamlined.Conduct social or behavioural research, including what values lead peopleto consume or conserve water in different ways.Undertake economic analysis of selected water effi cient and traditionaltechnologies, as this may help embed new technologies within existingand future urban areas and inform infrastructure planning.Develop technology selection guidance frameworks which account forlocal conditions and infrastructure.Develop service models and management frameworks for maintenanceof decentralised treatment systems.Suggested research initiatorsTechnology developers, universities andresearch organisationsAustralian Greenhouse Offi ce,environment agencies, local and stategovernments, universitiesTechnology developersTechnology developers, universities andresearch organisationsFederal environment and water agencies,research organisations (eWater, WaterQuality Australia)Water utilities, local governmentsState and local governments, waterutilitiesState and local governments, waterutilities and commissionsState and local government, waterutilities and commissionsState and local governments, thedevelopment industryState government agencies, waterutilities and development industries(noting that this should probably bedeveloped on a state-by-state basis)State and local government, waterutilities and development industry18


ReferencesReferencesAlternative Technology Association (2005) GreywaterProject Report, http://www.ata.org.au/wp-content/projects/smartwater_fi nal_report.pdfArgue, JJ and Argue, JR (1998) Total stormwatermanagement at Figtree Place, Newcastle, New SouthWales. Proceedings of 3rd International Conferenceon Innovative Technologies in Urban Storm Drainage,GRAIE, Lyon, FranceAtlantis Water Management (2007) Storm waterfi ltration & re-use system, http://www.atlantiscorp.com.au/projects/storm_water_fi ltration_&_reuse_systemAccessed 07/05/07Australian Bureau of Statistics (2005) Feature Article- Household Water Use and Effects of the Drought.Report 1350.0 - Australian Economic Indicators,Australia, http://www.abs.gov.au/Ausstats/abs@.nsf/Lookup/A0B004E8941B6FBFCA25702F007A793BAccessed 09/05/07Australian Water Association (2005) Status of Water inSouth East Queensland for the Courier Mail,http://www.awa.asn.auAustralian Water Conservation and Reuse ResearchProgram (2004) CSIRO Land and Water, http://www.clw.csiro.au/awcrrp/stage1.html Accessed 09/05/07Brisbane City Council (2004) Water for Today andTomorrow. An Integrated Water Management Strategyfor Brisbane. Making Brisbane a Water Smart CityBrisbane City Council (2005a) Water Sensitive UrbanDesign Engineering Guidelines: Stormwater (Draft)Brisbane City Council, Brisbane, http://www.brisbane.qld.gov.au/BCC:BASE:1220649970:pc=PC_1898Accessed 09/05/07Brisbane City Council (2005b) Water for today andtomorrow: a Proposed Integrated Water ManagementStrategy for Brisbane: Consultation Draft, datedNovemberCity of Melbourne (2004) Water Sensitive Urban DesignGuidelines, http://www.melbourne.vic.gov.au/rsrc/PDFs/Water/WSUDGuidelines.rtfClarke, JM and Brown, RR (2006) Understanding thefactors that infl uence domestic water consumptionwithin Melbourne, Proceedings of 7th Urban DrainageModeling and 4th Water Sensitive Urban DesignConference, MelbourneDepartment of Local Government, Planning, Sport andRecreation (2004) Towards <strong>Sustainable</strong> Housing inQueensland: Discussion paper, http://www.lgp.qld.gov.au/?id=2291 Accessed 09/05/07Department of Natural Resources and Mines (2006)South East Queensland Regional Water Supply StrategyStage 2 Interim ReportDiaper, C, Tjandraatmadja, G and Kenway, S (2006)<strong>Sustainable</strong> <strong>subdivisions</strong>: Review of technologiesfor integrated water services (Research report), CRC<strong>Construction</strong> <strong>Innovation</strong> Report, September 2006, http://www.construction-innovation.info/index.php?id=361Diaper, C, Sharma, A, Gray, S, Mitchell, G and Howe, C(2003) Technologies for the provision of infrastructure tourban developments – Canberra Case Study, CSIRO MITTechnical Report 2003-183Dillon, P, Pavelic P, Toze S, Rinck-Pfeiffer, S, Martin,R, Knapton, A and Pidsley, D (2006) Role of aquiferstorage in water reuse, Desalination Vol: 188, Issue: 1–3,Integrated Concepts in Water Recycling, 14–17 February2005Gardner, T and Millar, G (2003) The performance of agreywater system at the Healthy Home in South EastQueensland – three years of data, Proceedings ofOn Site-’03 Conference Future Directions for On-sitesystems: best management practice, University of NewEngland, 30 September – 2 October, Lanfax LaboratoriesGardner, T, Baisden, J and Miller, G (2004) Rainwaterfi rst fl ush devices: Are they effective? ConferenceProceedings, <strong>Sustainable</strong> Water in the UrbanEnvironment, August, Sunshine Coast, QueenslandGardner, T, Millar, G, Christiansen, C, Vieritz, A andChapman, H (2006) Urban metabolism of an ecosensitivesubdivision in Brisbane, Australia, Proceedingsof Enviro 06, 9–11 May, MelbourneGeolink (2005) Clunes Wastewater – Assessment ofOnsite and Community-Scale Wastewater ManagementOptions, http://www.geolink.net.au/infocentre/index.htmlGray, S (2004) Comparison of on-site greywater systemsand raintanks for reticulated water demand reduction inurban environments, Proceedings of IWA 6th SpecialistConference of Small Water and Wastewater Systems,11–13 February, Murdoch University, Fremantle, WAHatt, B, Deletic, A and Fletcher, T (2004) IntegratedStormwater Treatment and Reuse Systems, Inventory ofAustralian Practice, CRC Catchment Hydrology IndustryReportHurlimann, A and McKay, J (2003) Community Attitudesto an Innovative Dual Water Supply System at MawsonLakes, South Australia, Proceedings from Ozwater 2003,Perth, 6–10 AprilHurlimann, A and McKay, J (2004) Attitudes toReclaimed Water for Domestic Use: Part 2. Trust, Water,Journal of the Australian Water Association,31 (5): 40–4519


Institute for <strong>Sustainable</strong> Water Resources (2006)Integrated Stormwater Treatment and Harvesting:Technical Guidance Report ISWR Report 06/05Landcom (2004) Water Sensitive Urban Design (WSUD)Policy PackageLandcom (2006) Report: Wastewater reuse in the urbanenvironment: selection of technologies, http://landcom.com.au/downloads/fi le/Wastewater_reuse_technology_report_links3.pdfMarsden Jacob Associates (2007) The economics ofrainwater tanks and alternative water supply options.A report prepared for the Australian ConservationFoundation, Nature Conservation Council andEnvironment Victoria, http://www.acfonline.org.au/uploads/res_rainwater_tanks.pdf Accessed 09/05/07Mitchell, VG (2004) Integrated Urban WaterManagement: A review of current Australian Practice,Australian Water Conservation and Reuse ResearchProgram, CSIRO Land and WaterNatural Resources Mines and Water (2006) South EastQueensland Regional Water Supply Strategy Stage 2Interim ReportPo, M, Kaercher, JD and Nancarrow, BE (2003)Literature review of factors infl uencing publicperceptions of water reuse, CSIRO Land and Water,Technical report 2003/54. Updated 2004, http://www.clw.csiro.au/publications/technical2003/ Accessed07/05/07Po, M, Nancarrow, BE, Leviston, Z, Porter, NB, Syme,GJ and Kaercher, JD (2005) Predicting CommunityBehaviour in Relation to Wastewater Reuse: Whatdrives decisions to accept or reject? CSIRO Waterfor a Healthy Country National Research Flagshipreport series, http://www.clw.csiro.au/publications/consultancy/ Accessed 07/05/07Priest, G, Anda, M, Mathew, K and Ho, G (2003)Domestic greywater reuse as part of a total urbanwater management strategy, Proceedings of OzwaterConvention & Exhibition, AWA 20th Convention, 6–10April, Perth, WARadcliffe, JC (2004) Water Recycling in Australia.Review undertaken by the Australian Academy ofTechnological Sciences and Engineering: Melbourne,253 ppSEQ Offi ce of Urban Management (2005) South EastQueensland Regional Plan 2005–2026, QueenslandOffi ce of Urban ManagementState Government of Victoria (2004) Mediarelease from the Offi ce of the Premier, http://www.dpc.vic.gov.au/domino/Web_Notes/newmedia.nsf/798c8b072d117a01ca256c8c0019bb01/60a4e3dd69854c04ca256f10007aab35!OpenDocumentAccessed 07/05/07Stormwater Industry Association Queensland (2005)Storming into the Future, Stormwater as a resource.14–15 April at the Courtyard Marriott Resort, GoldCoast, http://www.stormwater.asn.au/qld/archives.aspStormwater Industry Association Queensland (2006)Comment on SEQ Regional Plan,http://www.stormwater.asn.au/qld/SEQ-RegPlanReview-SIAQ2006.pdf Accessed 09/05/07Sydney Water (2006) Sydney Water Corporation WaterConservation and Recycling Implementation Report2005–2006Urban Stormwater Initiative Executive Group (2004)Urban Stormwater Management Policy for AustraliaDraft 18 , http://www.lga.sa.gov.au/webdata/resources/fi les/Draft_Urban_Stormwater_Management_Policy_for_SA.pdf Accessed 07/05/07Wong, THF (ed) (2006) Australian Runoff QualityGuidelines, Institution of Engineers, AustraliaWSAA (2005) The Australian Urban Water IndustryWSAAfacts, Water Services Association of Australia,Melbourne, Victoria20


CRC for <strong>Construction</strong> <strong>Innovation</strong> participantsI N D U S T R YG O V E R N M E N TDepartment of Main RoadsDepartment of Public WorksDepartment of State Development,Trade and <strong>Innovation</strong>R E S E A R C H


<strong>Sustainable</strong> <strong>subdivisions</strong>:Review of technologies for integrated water servicesImproved planning and management ofwater in Australia is essential to ensurereliability of water services and to supportthe ongoing growth of our cities. <strong>Sustainable</strong><strong>subdivisions</strong>: Review of technologiesfor integrated water services deals withemerging water supply, wastewatertreatment and reuse technologies athousehold, cluster and subdivisional scales.With its focus on the South East Queenslandregion, this review includes:• a discussion of the impact of subdivision design on water use• a literature review of water management technologies, either in use orunder development, which offer alternative approaches to existing waterservices• an examination of eight case-study sites outlining the benefi ts and issuesassociated with the various technologies in an integrated water system• suggestions for future projects for understanding and mitigating thebarriers to implementation of the water management technologies.This publication forms part of the <strong>Construction</strong> <strong>Innovation</strong> <strong>Sustainable</strong><strong>subdivisions</strong> series comprising Energy-effi cient Design (pictured below) andVentilation (available early 2008).Partners in progressThe partners involved in this research:IndustryGovernmentDepartment of Public WorksResearch • the slope of the lot wi l either improve or hinder solar access; however lots with a slopeof over 20 per cent automatica ly receive a 1-star rating, regardless of slopeorientation.• the goal is to rate 5-star lots at 80 per cent of the total, with the remainder rating either4 or 3 stars.In the southern states of Australia, the focus is on designing to increase solar access andreduce the energy used to heat the dwe ling. The aim was to test the SEDA tool for itsappropriateness for SEQ, where the focus is on preventing exposure to too much sun and oncapturing the prevailing breezes.Assessing subdivision design in SEQIn assessing a number of subdivisional layouts, the project found that, although <strong>subdivisions</strong>with larger lots (over 560m²) could achieve the SEDA guidelines, the increasingly popular,sma ler lot-size <strong>subdivisions</strong> were fa ling we l short of the mark. The fo lowing examplesillustrate this outcome.Figure 4: Subdivision 1 Figure 5: Subdivision 2Figure 6: Subdivision 3 Figure 7: Subdivision 48The first subdivision (Figure 4) had a high proportion (50 per cent) of sma l lot sizes 3 , thelowest average lot size (520m²) and the lowest percentage (47 per cent) of 5-star lots (Figure8).In the second subdivision, the average lot size was 923m²,making it easier for the lots to comply with the SEDAguidelines. Here, 91 per cent of the lots rated 5 stars.The average size of lots in the third subdivision was 890 m²and 80 per cent of the lots rated 5 stars. Those that did notachieve this rating were steep lots (over 20%) whichautomatica ly received 1 star.At the other end of the scale, subdivision 4 had the largestaverage lot size (981m²) the largest percentage of largelots 4 (30 per cent), yet had the second lowest percentage(58 per cent) of 5-star lots due in part to constraints imposedby the topography.The project found that the SEDA tool is a good starting point for subdivisional design. At thevery least, it quantifies the number of lots that are likely to require more intensive designsolutions and alternative patterns. Using the tool could trigger a re-examination of thesubdivisional layout to assess alternative layout designs.Is there a correlation between lot rating and a dwe ling’s energy efficiency?Rating dwelling energy-efficiency in South-EastQueenslandAmong the currently available thermalprograms in Queensland, the Building EnergyRating Scheme (BERS) gives the most reliable,relevant results in tropical and subtropicalclimates, but BERS and, indeed, all the currentthermal programs are deficient in modellingnatural ventilation effectively.One of the reasons to improve the NationwideHouse Energy Rating Scheme (NatHERs) wasthe need to improve ventilation modeling intropical and subtropical climates and providedesigners with a tool to augment passive3 Based on terms used by the key informants, a ‘sma l’ lot was cited as between 400 m² and 560 m².4 A ‘large’ lot was cited as more than 560 m².9Figure 8: Subdivision 1 – Proportion of lot ratings1 Star34%5 Star47%2 Star4 Star 3 Star 8%3% 8%Copies of the industry bookletwill be available from:Cooperative Research Centrefor <strong>Construction</strong> <strong>Innovation</strong>9th Floor, L Block, QUT Gardens Point2 George Street, Brisbane QLD 4000 AustraliaTelephone: (07) 3138 9291Email: enquiries@construction-innovation.infoWeb: www.construction-innovation.infoCRCs bring together researchers from universities, CSIRO and other government laboratories, and private industryor public sector agencies, in long-term collaborative arrangements which support research and development and education activities toachieve real outcomes of national economic, environmental and social signifi cance.August 2007

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