Part 1 of this book“Milestones in Water Reuse: The Best Success Stories”presents a number of case studies showing how water managers have applied integrated water management approaches to meet the future water needs of cities.
Table1Highlightsandlessonslearnedfromtheselectedcasestudiesofintegratedwaterresourcemanagementwithwaterreuse. Project/ locationStart- up/capacityTypeofusesKeyfiguresDriversand opportunitiesBenefitsChallengesKeystosuccess Sydney, Australia2006,2010 and2014 Metropolitan WaterPlans Industry,Agriculture, Toiletflushing, Wateringgardens, Carwashing
Watersavings:145Mm3/yr by2015. Totalvolumeoftreated wastewater:510Mm3/yr. Totalvolumeofrecycled water:70Mm3/yrby2015. Desalination:upto 90Mm3/yrduringdroughts.
Demandreached capacityofthe existingsupply. Supplyrestricted duetoshortfallin droughtsecurity.
Reduceduser demands. Increaseddiversity, reliabilityandsecurity ofwatersupply. Newriverwater suppliesdeferred forabout20years. Improved environmentalflows andriverwaterquality.
Impactsofclimate changeonsupplies. Adaptivemanagement tochangingconditions. Managementof competingsources. Communityeducation.
Governmentcommitment. DirectionoftheMetropolitanWater Planbychiefexecutiveofficers. Majorwaterefficiency,water conservationmeasuresandwater recyclinginitiatives. Additionalsuppliesincluding groundwateranddesalination toincreasedroughtsecurity. WestBasin, California United States
Since1995 190,000m3/dIndustry,Irrigationofa golfcourseandpublic accesslandscape, Toiletflushing,Aquifer rechargeforasalt intrusionbarrier
Treatmentcapacity: average132,500m3/d. Productionoffivetypesof recycledwater. Over160kmofdistribution pipelines. Over350customers. Threesatellitetreatment facilities. Currentlyfifthphaseof expansiontoreach 190,000m3/d.
DevelopLocal WaterSupply. DevelopReliable WaterSupply.
Reduceddependence oninterruptible importedwater. Avoidlossofindustry inregion. Recognisedeconomic, environmentaland socialbenefits.
Developingseparate facilitiesand infrastructure. Meetingwaterquality requirementsfor industrialcustomers.
Reliablesourceofwaterwhen potablesuppliesareuncertain. Matchwaterqualitywiththe intendeduse. Recycledwaterprovidesassured watersupplyandislessexpensive thancomparablepotablewater, evenaftertheusers’investment inretrofittingcosts. Publicoutreachandeducation achieveacceptance. NEWater, SingaporeSince 2002 531,000m3/d
Airconditioning, Coolingandboiler waterforindustries, Ultracleanwaterfor semiconductorand electronicindustries, Augmentationof freshwaterwater reservoirs(2.5%) Totalvolumeoftreated wastewater:511Mm3/yr. Totalvolumeofrecycled water:194Mm3/yr. Recycledwatertariffs1.22 S$/m3. Majorbenefits:Recycled watermeets30%oftotal waterdemandcurrently(up to50%inthelongterm).
Water-stressed region. Limitedlandto collectrainwater. Increasingwater demand.
Additionalwater resource. Attainwatersupply sustainabilitywith populationgrowthand socioeconomic development. Independentofclimate changeandextreme weatherconditionsuch asdroughts. Reducewastewater effluentdischarge. Ultra-purewaterquality preferredby semiconductorand waferfabrication industries.
Initialskepticism expressedby semiconductorandwafer fabricationindustrieson suitabilityofNEWaterfor theirprocessuse. Needtransmissionand distributioninfrastructure whichiscostintensive. Strictoperationalcontrol ofwastewatertreatment plantsandNEWater plants. Comprehensivewater qualitymonitoringfrom sourcetopointofuse. Publicacceptancefor indirectpotableuse.
Multi-barrierapproachtoensure goodwaterqualitywhichincludes: sourcecontrol,highproportion ofdomesticwastewater, comprehensivesecondary wastewatertreatment,useof provenadvancedtechnologies, comprehensivewaterquality monitoring,adheringtostrict operatingprocedures. Asingleagencymanaging wastewateranddrinkingwater createdsynergyoftakingaholistic approachonwaterresource managementincludingwater reuse. Stronggovernmentsupportand effectivepubliceducationand communication.
MilestonesinWaterReuse:TheBestSuccessStories
Costa Brava, Spain
Since1998 13facilitiesIrrigationofgolf courses,parks,public landscapeandhome gardens, Environmental enhancement (wetlandsand biodiversity restoration) Volumetreated wastewater: 30-35Mm3/yr. Maxvolumeofrecycled water:6.4Mm3/yr(2010). Stringentwaterreuse standards:,1,,100, ,200E.coli/100mL (privategardens, agriculturalandgolf courseirrigation) Lackofwater resources. Highenergy consumptionof drinkingwater cycle. Taxincreasein drinkingwater use.
Netincreaseof resources. Simultaneouswater andenergysavings. Reductionof discharges. Potentialeconomic savings.
Reliabilityinquality. Automationforonline detectionoffailures. Pricing. Contractualagreement withmunicipalitiesand/or end/users. Refiningofpresent regulations.
Gradualdevelopmentand improvementofwaterreuse projects. Dedicatedoperationand maintenanceoffacilities. Lookforthesuccessofendusers. Collaborationwithresearchers. Activedivulgationofprojectsand theirbenefits. CyprusSince2004 Totalcapacity 150,000m3/d
Agriculture, Landscapeirrigation, Aquiferrecharge, Industrialuses
Totalvolumeoftreated wastewater:19Mm3/yr. Totalvolumeofrecycled water:15Mm3/yr. Recycledwatertariffs: 0.05–0.21€/m3. Waterreusestandards: ,5FC/100mL.
Complywith Directive 91/271/EECby 2012. Reuseof100% treatedeffluents.
Securegoodquality waterandprotect environment. Substantialcontribution totheisland’swater balance. Savefreshwaterfor otheruses.
Hugeinvestments neededinaperiod ofeconomiccrisis. Efficientapplicationin appropriateusesandthe island’swatercycle. Secureadequatequality controlsandwaterquality.
Trustthebenefitsofwaterreuse andloyaltyinimplementation. Systematicworktoempower acceptance. Monitoringanddissemination ofwaterreuseoutcomes. Ensuringgoodwaterquality. Tianjin, China2007 260,000m3/dToiletflushing, Landscapeirrigation, Industrialuse(cooling waterforpower plants, constructionsites)
Totalvolumeof treatedwastewater:726.4 Mm3/yr. Totalvolumeofrecycled water:94.9Mm3/yr. Totalcost:0.33–0.41€/m3. Recycledwater tariffs:domesticwater0.28 €/m3;industrialreuse0.52 €/m3. Waterreusestandards: ,3E.coli/L.
Nationalandlocal policy& incentives. Highwater scarcity. Availabilityof largeusers (powerplant).
Conservingfreshwater resources. Savinggreatamount ofhighqualitywater. Improvingthe environment.
Optimizingthecategory ofreuse. Increasingtheratioof wastewaterreclamation. Expandingthescaleof reclaimedwaterandthe pipelineconstruction. Increasinglandscape uses.
Waterscarcity. Governmentpromotionand decisions. Reclaimedwatertreatment technologiesenablingto consistentlyachievethewater qualityrequirementsforfitto purposeusesofrecycledwater. Theroleofwaterreuse25
Chapter 1 describes the“Water for Life”integrated water management plan for Sydney, the largest city in Australia. Limits on the existing sources of water and drought risks have been addressed through an adaptive management strategy in which large savings from water efficiency programs have been combined with new supplies of recycled water and drought contingency supplies from groundwater and desalination to increase drought security. The need for new fresh water supplies has been deferred for two decades while, at the same time, additional water has been allocated for environmental flows to improve river water quality. Recycled water uses include urban and residential use, industrial use, agricultural use and replacement environmental flows to increase reservoir yields.
Chapter 2 describes the West Basin Water Recycling Scheme in California which produces “designer”recycled water tailored to meet customer needs. Recycled water quality is tailored to meet the specific needs for urban landscape irrigation, industrial cooling water, boiler feed water and for aquifer recharge. In a region where normal supplies are uncertain in drought times, the recycled water is a reliable source of water for customers and less expensive than new fresh water supplies. This concept, implemented and successfully operated since 1995, enables successful implementation of integrated resource management in urban and protected areas.
Chapter 3 describes Singapore’s“Four Taps”water strategy to diversify its water supply. As an island state, Singapore has insufficient catchment area to supply all of its water needs but does not wish to increase its dependence on imported water.
Singapore’s NEWater schemes provide purified recycled water for industrial use and for reservoir recharge. NEWater now provides 30% of Singapore’s water needs and is a key element in achieving water sustainability in Singapore.
The gradual development of water reuse in Spain’s Costa Brava region (Chapter 4) has resulted in beneficial use of recycled water for agriculture, landscape irrigation, urban non-potable uses, environmental uses and for aquifer recharge. In a dry region, gradual and careful development of water recycling has enabled the local water authorities to supply growing water needs.
Chapter 5 describes water recycling in Cyprus, another water-stressed country. The planned implementation of water recycling systems has enabled the community to maximise the beneficial use of available water, minimise discharges and improve environmental water quality. The recycled water is being used for irrigation of permanent crops, urban landscape irrigation, sporting fields and for aquifer recharge.
Water shortages across the whole of northern China have posed major challenges in supplying water for urban and industrial needs without adverse public health and environmental effects. The case study in Chapter 6 describes planned water reuse in the City of Tianjin which has adopted water recycling as its principal strategy to overcome water scarcity. The recycled water is being used for municipal uses, industrial uses and to create scenic lakes to enhance the local environment.