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Journal of the Australian Water Association

Volume 33 No 7 November 2006

OPINION AND INDUSTRY NEWS OPINION DDay, President, AWA let's Plug the Holes Unchartered Waters CDavis, CEO, AWA NApostolidis, Water Business Stream Leader and Director, GHD Ply Ltd My Point of View AWA NEWS Includes: Young Water Professionals; WaterAid Australia; Oz·AQUAREC Seminar CROSSCURRENT Water Industry News, National Issues & Policy, International, States, Personalia, Honours and Awards AWA MEMBERSHIP NEWS New Members

4 5 6

8 12

28

PROFESSIONAL DEVELOPMENT NATIONAL EVENT CALENDAR Membranes - the Frontier for Superior Treatment and Reuse; Book Review; Sustainable Water Management Projects Awarded; AWA Two-day Seminar

TECHNICAL FEATURES (i ·,

29

30

indicates the paper has been refereed)

RECYCLING: COMMUNITY CONSULTATION How Does Recycling Fit in Sydney's Water Cycle? Various opportunities for recycling and the associated issues. ~ Role of Community Participation and Partnerships: The Virginia Pipeline Scheme Success was achieved by participation and partnerships. Melbourne Office Worker Attitudes to Recycled Water Use For the City of Melbourne's 'six-star' Council House 2 MEMBRANE TECHNOLOGY • Plans for Seawater Desalination in California California and Australia have much in common. The Joe White Maltings MBR/RO Water Recycling Facility Areport on post-commissioning performance SMART SEWERS Smart Sewers - RIGS, AGold Coast Innovation Gold Coast Water reduces inflow and infiltration WATER RESOURCES ASustainability Framework for the Australian Water Industry The best of current strategic planning and sustainability assessments -. ] Rainwater Harvesting: Revealing the Detail Comparing three modelling tools for a range of Australian climates. PROJECT DELIVERY Project Delivery and Commissioning: An Integrated Approach Fully integrate commissioning activities info design and construction processes.

Pvon Huben, DCho

40

GBKeremane, J McKay

so

AHurlimann

58

NVoutchkov

66

MNewland, BGibbs

75

BDouglas

78

5 Lundie, GPeters, NAshbolt, ELai, DLivingston

83

5 ALucas, PJ Coombes, MJ Hardy, PMGeary

89

ZSlavnic

95

WATER BUSINESS NEW PRODUCTS AND BUSINESS INFORMATION · SPECIAL FEATURE: PUMPS ADVERTISERS' INDEX

98 112

OUR COVER Water recycling is increasingly on the agenda as we enter our tenth summer of below average rainfall with warnings of a recession in farm production. A recent survey of growers at the Virginia Pipeline Scheme in South Australia found that irrigators were very happy to have a secure supply of recycled water. Earth Tech, a Tyco International company, operates the Virginia Pipeline Scheme and other water recycling schemes that deliver over 10% of Australia's recycled water. Pictured is Mark Schruers, a recycled water customer at Melbourne's Eastern Irrigation Scheme. For more details see page 50. Photo courtesy of Leif Ericson, Earth Tech.


~ AWA CONTACT DETAILS • 'Promoting the sustainable : ~ management of water' POSTAL ADDRESS PO Box 388, ARTARMON NSW 1570 EMAIL info@owo .osn.au

WEBSITE http://www.owo.osn.au PRESIDENT Darryl Doy· president@owo .osn.au

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COPYRIGHT AWA Water Journal is subject to copyright and may not be reproduced in any format without written permission of AWA. To seek permission to reproduce Water Journal material email your request to: jsoge@owo.osn.au

2 NOVEMBER 2006

Water

Journal of the Australian Water Association ISSN 03 10-0367

Volume 33 No 7 November 2006

AWA WATER JOURNAL MISSION STATEMENT 'To provide o print journal that interests and informs on water matters, Australian and international, covering technological, environmental, economic and social aspects, and to provide a repository of useful re fereed papers.' PUBLISH DATES Water Journal is published eight times per year: February, March, May, June, August, September, November and December EDITORIAL BOARD: Chairman: FR Bishop BN Anderson, TAnderson, CDiaper, GFinlayson, AGibson, GA Holder, BLabza, MMuntisov, CPorter, DPower, FRoddick EDITORIAL SUBMISSIONS Water Journal invites editorial submissions for: Technical Papers and topical articles, Opinion, News, New Products and Business Information. Acceptance of editorial submissions is subject to editorial board discretion. Email your submissions to one of the following three categories: I. TECHNICAL PAPERS AND FEATURES Bob Swinton, Technical Editor, Water Journal: bswinton@bigpond.net.au AND https:/ /zeus.econ.umd.edu/wj (Editorial Express) Papers of 3000-4000 words (allowing for graphics); or topical stories of up to 2,000 words. relating to all areas of the water cycle and water business. Submissions are tabled at monthly editorial board meetings and where appropriate are assigned to referees. Referee comments will be forwarded to the principal author for further action. See box on page 8 for more details.

2. OPINION, INDUSTRY NEWS, PROFESSIONAL DEVELOPMENT Jennifer Sage, jsage@awa.asn.au Articles of l 000 words or less 3. WATER BUSINESS Brian Rault, National Sales & Advertising Manager, Hallmark Editions brian.rault@halledit.com.au Water Business updates readers on new products and associated business news within the water sector. ADVERTISING Brian Rault, National Sales & Advertising Manager, Hallmark Editions Tel: 61 3 8S34 S014 (direct), 61 3 8S34 S000 (switch), brian.rault@halledit.com.au Advertisements are included as an information service to readers and are reviewed before publication to ensure relevance to the water environment and objectives of AWA. PURCHASING WATER JOURNAL Single issues available @ $12.50 plus postage and handling; email dwiesner@awa.asn.au BACK ISSUES Water Journal back issues are available to AWA members at www.awa.asn.au PUBLISHER Hallmark Editions, PO BOX84, HAMPTON, VICTORIA 3188 Tel: 61 3 8534 5000 Fax: 61 3 9530 8911 Email: hallmark.editions@halledit.com.au

Journal of the Australian Water Association


rofessional develo

problems of disposing the water if it is of unusable quality. The subtleties of aquifer storage and recovery (ASR) were explained by Eric Rooke of Australian Groundwater Technologies. Alchough there are some 14 sites in Australia, USA and Spain where reclai m ed water is sto red in confi ned aquifers, ASR is not currently used in any Australian mines, but a pilot project is in operation for the brown coal mine at Aireys Inlet, Victoria. An 'ap pl ication' of AMD and ASR is 'In Situ Leaching' which is employed at the Beverley uranium deposit, South Australia, the most technically advanced in the world, approved after exhaustive hydrogeological investigations. A pattern of 24 injection and 15 extraction bores enables 12 ML/d of oxidised acid mine water to be cycled through the confined strata, thereby dissolving rhe uranium sales which are subsequently extracted by ion-exchange. Rick Pobjoy, of Hearhgare Resources, explained the aquifer dynamics, rhe monitoring of adjacent aq ui fe rs and rhe investigations on the optimal spacing of the bores, all of wh ich has implications for ASR. Dewatering a mi ne yields a strea m of water which is freq uently too co ntaminated to use, even in rhe process stream.The reopening of rhe old Bendigo gold workings presen ted a form idable challenge because the water coul d nor be discharged to the urban environment. Peter Macintosh, of QED Occrech, outlined the complicated treatment plant which has been installed. Although the co ntent of arsenic as well as metals was anticipated, the wa ter co ntained a significant co ncentration of BOD. The so urce? Probab ly from the hundreds of old mi ne shafts which infest Bendigo and its suburbs, some of which have been used as co nven ient rubbish dumps over th e past 100 years. The treated water is cu rrently discharged to a dam and is of sufficiently high quality to be considered for re-use. Peter's presentation was wide- ranging, ill ustrating a number of case studies of mine-water treatment, mainly involving membranes. It included some initial failures caused by dissolved silica. He noted rhar recycling of membrane treated water can lead ro accu mulation of the more mobile ions, and cited six months' investigation to elucidate the cause of high nitrate in a nickel process ing facility. Neil Palmer, United Utilities, also focused on hydrometallurgy and rhe 24 ML/d required for Queensland Nickel (Q N l). After initial problems with a co mbined MF and RO plane, an all iance co ntract was established to tackle the problem and the

Water Recycling Facility now recycles 35% of QNI refinery's demand from the mine's tailing ponds. Neil's paper quotes the flux of the membranes over the rwo and a half year operation. The cost is approximately $1.50/kl, but the cheaper supply from the borefield is limited. T o enable rhe planned expansion of production by a factor of four the next project is the reuse of Townsville's municipal wastewater. David Cohen ill ustrated rhe cou rse of the contract by Go lder Associates to limeneutralise the 10,500 ML of water in the old Mount Morgan open-cut mine in Queensland, from pH 2.8 to acceptable quality fo r discharge to the Dee River. The calcium sulphate sludge is rerurned to the pit for eventual closure. T he plant was co mmissioned in March 2006. Brook Hill, Environmental Manager for Worsley Parsons, gave a fascinating disco urse on advances in the transport and storage of mine railings, in a range of climates. Failure of wet railings dams is an ever-present risk, particularly in seismic zones. Dewatering the tailings to th ick slurries, which can be used as back-fill, or even to a paste, which ca n be stacked as a solid, are current best practices, with the advantage in arid zo nes being recovery of water for re-use.

The worldwide experience of Veolia on industrial water treatment was vividly reviewed by Les Lloyd, with practical advice on what wo rks and what doesn't. He covered the fu ll range of solutions available and quoted three mining operations, one of which was the co nstruction of the Bend igo plane mentioned by Peter Macintosh. Brine disposal always presents problems and, if all else fails, a crystall ising evaporator is ava ilable. Almost as a finale , Andrew Simon, of Sim on T ech nical Services, tabulated the qua li ty criteria fo r all the possible uses of water at a mine and mineral processing site, and li sted the technologies available for controlling sca le and co rrosion. His presentat ion is almost a wo rk of reference. As Dr Diane Wiesner said in her closing rema rks, with increasing environmental and eco nom ic pressures on the use of water for mining and mineral processing, the new skills and tech nologies in water engineering and chemistry need to be recognised.

A CD ROM containing all the presentations and some ofthe papers is available from the A WA Bookshop. Price $75 including postage (within Australia). Enquiries: Diane Wiesner 02 9495 9906 or bookshop@awa.asn.au.

0 Contaminated site assessment 0 Acid sulfate soil 0 Monitoring and containment 0 Occupational health and safety An array of services are readily available that go beyond the traditional laboratary to investigate and solve your complex problems by using the highest level of proven scientific expertise and instrumentation. You can easily and quickly access our Western Australian based group with: 95 staff (including 17 Ph D's, many onsite NATA assessors, tertiary qualified technologists); _ _C _H_E_M_I_S_T_R_Y_--1 The most extensive range of NATA accreditation across many disciplines; More CENTRE than 25 current academic and industry research initiatives and; 1800 666 322 110 years of problem solving experience in the WA environment N VATA (including over 90 years with acid sulfate soils). Please cantact us lo discuss how we can assist you now.

_A

Journal of the Australian Water Association

water

NOVEMBER 2006 39


fereed paper

HOW DOES RECYCLING FIT IN SYDNEY'S WATER CYCLE? P von Huben, D Cho Abstract This paper, based on publicly available reports and information , presen ts a summary of Sydney's water cycle w ith a discussion of che curren t and future pressures facing the city's water su pply. An overview is given of the various opportunities for recycling and the associated issues. One particular factor chat is often overlooked is chat scudies u ndertaken by the Hawkesbury-Nepean River Management Forum (HN RMF) favour recycling created effluent in Western Syd ney rather than discharging ic to the Hawkesbury-Nepean R iver and its tributaries. H NRMF demonstrated chat minimising the d ischarge of tertiary created efflu ent, through recycling, provides significant environ men cal benefits to the health of the H awkesbury-Nepean River as ic minimises che concentration of nutrients in che river. This improvement in river health can provide potable water savings as less dam water needs to be released to the river to achieve che same river water q uality. However these benefits o f recycl ing only become apparent when the entire water cycle is caken into consideration.

2002 I 2003 Data - Total Usage: - Discharge to River: - Net Volume Removed from River:

- 540 GUyr

s,,,,

Tasman

Figure 1. Sydney's Water Balance .

Some benefits of recycling only become apparent when the entire water cycle is taken into consideration.

Introduction Syd ney's water shortage has in pare been caused by a lack of long term plann ing and has been exacerbated by che cu rrent decline in rainfall over the catch ment area. Pop ulatio n growth and demands fo r greater allocation of water for environ mental flows will place additional pressure on che already scant water supplies. However, these future deman ds also provide opportunities for innovative approaches to manage the cicy's water cycle. The scare go vernment's response to Sydney's water shortage was first announced in the 2004 Metropolitan Water Plan (NSW Government, 2004) and more recen tly in the 2006 Mecropolican Water Plan (NSW Government, 2006 b). The Metropolitan Water Plan outlines a number

Philip von Huben presented an early version of this paper at the Young W ater Professiona ls Confere nce, February, 2006.

of measures to be taken including desalination of seawater, transfers from the Shoalhaven, demand m anagemen c, recycling and accessing groundwater. The government's push for desalination gen erated a great deal of public debate includ ing a number of alcernacive proposals such as recycling treated efflu en t for indirect potable consumption (Total Environment Centre, 2005). In the Feb ruary 2006 l'rogress Report (NSW Government, 2006 a) the government announced chat a modified direction would be taken , with a greater focus on recycl ing and demand management. T here have been n umerous investigations of recycl ing opportunities in Sydney including a number of documents produced during che Clean Waterways Programme in che early 1990s (Water Board , 1992) . T o dace there has been limited implemencacion o f recycling projects with primarily a focus on relatively small scale schemes such as golf

40 NOVEMBER 2006 Water Journal of the Australian Water Association

course irrigatio n at a number of Sewage Treatment Planes. A key reason for the relatively low implem en tation of large scale recycling is chat the cost is often perceived co outweigh the benefits. Th is can be largely attributed co che relatively low cost of ob taining water from the ex isting water sup ply system, be it potab le water or river water. Each recycling project is unique and can have specific goals and d rivers. For example, che first large scale recycled water project implem ented by Sydney Water was che Rouse Hill Recycled Water Area Project wh ich supplies created effluent co over 15,000 new homes via a 'th ird pipe' system for coilec fl ush ing and outdoor use, such as irrigation of gardens. Whilst ch is project does save potable water, when ic was origin ally conceived che key driver for its implementation was enviro nmental outcomes. Recycling a portion of the created effluent back co che new ho mes reduces the volume of effluent chat is disch arged co Second Ponds Creek resulting in improved creek water quality. The R ouse H ill example illustrates chat analysi ng recycling projects in terms of che co mplete water cycle can identify outcomes chat are often missed , such as environmental benefits.


EC

WATER STORAGE SOLUTIONS

NEW GENERATION IN

CORROSION RESISTANT GRP

WATER STORAGE POTABLE WATER APPROVED SUPERIOR STRENGTH EARTHQUAKE RESISTANT

250

LITRE TO

5

LITRE CAPACITY

MILLION BUILT TO WITHSTAND 6

TIMES

NORMAL WORKING PRESSURE


In 2005 SKM worked with the Department ofln frasrructure, Planning and Natural Resources, and more recently with Sydney Water, co assist in the development of the recycled water component of the 2006 Metropolitan Water Plan. This work provided a basis fo r a number of rhe recycling projects that are currently being further investigated by Sydney Water.

Table 1. Summary of Sydney's Water Cycle. financial Year

Water Restrictions Sydney and Wollongong Potable Water Usage Total Effluent Discharged Effluent Discharged to Hawkesbury Nepean as Percentage of Total Potable Water Usage Total Discharge as Percentage of Total Potable Water Usage

Summary of Sydney's Current Water Cycle The Hawkesbury-Nepean River is the dominant river system in Sydney and provides the majority of Sydney's water demand with Warragamba Dam the source of 80% of the city's supply. The remainder of the water is sourced from the Woronora and Shoalhaven Rivers. Table 1 and Figure 1 summarise key statistics and illustrate that only 10% of the total potable usage, or 12% of rhe water removed from the Hawkesbury-Nepean River, is returned to rhe river as relatively high quality tertiary effluent (Sydney Water Corporation, 2004). T he remainder is discharged to the ocean or lost through outdoor usage. Table 1 demonstrates the impacts of introducing mandatory water restrictions in October 2003. From 2002/2003 to 2003/2004 the overall water consumption decreased, even though rhe serviced population increased by 1% (Sydney Water Corporation, 2004).

and stormwater, water extraction for town supply and irrigators, particularly during d ry periods, and modifications to the shape and size of the river channels. These changes have resulted in algal blooms, growth of aquatic weeds and loss of biodiversity and river amenity (HNRMF, 2004).

Current and Future Pressures on Water Supply Sydney's water system has been raced to have a long term safe yield of 600 GL/yr (HNRMF, 2004) excluding any future impacts from climate change. Figure 2 demonstrates that in 2002-2003 , without water restrictions, more water was used than is sustainable. This situation has nor occurred overnigh t, is not short term drought dependent, and has been fuelled by Sydney's populat ion growth . Charts of yearly rainfall data indicate that there has been a sharp decline in the average rainfall in the Warragamba catchment in the lase few years. An example is shown in Figure 3 with rainfall data from Wanganderry (Bureau of Meteorology, 2005).

The Hawkesbury-Nepean River has been significantly affected by Sydney's urban water cycle with key issues being the reduced volume of fl ow, loss of variability in flow, eurrophicarion from nutrients discharged from tertiary treated effluent

SYDNEY'S HISTORICAL WATER USAGE & FUTURE WATER REQUIREMENTS [EXTRAPOLATED USING CURRENT DEMAND OF 411 LITRES/CAPITA/DAY] ORIGINAL YIELD

- - - - - - - - - - - - - - - - - - - ---:-=.ns-:flil 720

REVISED SAFE _ _ _a_l _a I _ YIELD

a

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2003/2004

Voluntary restrictions 14th Nov 2002

634 GL/yr 479 GL/yr

Mandatory restrictions 1st Oct 2003 563 GL/yr 451 GL/yr

9%

10%

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80%

Analysis of a 3 year rolling average highlights rhe decline in rainfall in the catchment since 2000, however it also indicates that similar dry periods have occurred p reviously such as in 1967 and 1982. Similar trends can be observed at ocher locations within the Warragamba Dam catchment area, such as at Goulburn and Lithgow, and with 5 and 10 year rolling averages. The added pop ulation since rhe 1980's has meant that Sydney is drawing more water from the dam than is sustainable and hence the recent drop in catchment rainfall has had a more significant impact on supply levels th an similar previous dry periods. Continued population growth threatens to widen the gap between demand and sustainable yield in the future. Long term rainfall records indicate that New South Wales faces a general weather pattern which co nsists of 40-50 'd ry' years followed by a similar period of 'wee' years. Indications are that we are at the start of another 40-50 year dry period (HNRMF, 2004). Global climate change is another facto r that has nor been accounted for in the current sustainable yield figure of 600 GL/yr. A CSIRO report on climate change in NSW (CSIRO, 2004) indicates a future tendency to drier seasonal-average condi tions and increased drought frequency. Both of these predictions would place further stress on water resources. The NSW Government has com missioned a study to determine the impacts of climate change on both water supply and water demand across Sydney. The results of this study will be available in two to three years time.

Hawkesbury Nepean River

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Figure 2. Sourced fro m 4th Sydney Water Project, PENGOs 2003.

42 NOVEMBER 2006

Water

Journal of the Australian Water Association

YEAR

At rhe same rime as the increased demands on the water sup ply from the city, there has been an increased fo cus o n effective environmental management of the city's river systems. The HNRMF was established by rhe state governmen t in 2001 to make recommendations on environmental flow provisions. The HNRMF investigated suitable environmental flow regimes on the


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Figure 3. Yearly Rainfall Data for W arragamba Catchment with 3 Year Rolling Average.

basis of integrated water cycle management so that the water demands of the city and the environment could be balanced. The H NRMF commissioned a number of separate studies which culminated in the release of a report "Water and Sydney's Fu ture" in March 200 4 containing a number of reco mmendations. The key recommendation from the HNRMF was to establish specific environmental flow regimes for each of Sydney's major dams with the goal of protecting the health of the HawkesburyNepean River and the $2,000 million per year tourist, agriculture, fis hing and recreation industries that depend on the n ver. The specific environmental flow regime recommended by the H NRMF was based on releasing water from the dam to the river in proportion to the inflow to the dam so that there is natural variability in the downst ream river flow. When there is a large inflow to the dam only a percentage of this flow will be released to the river and the majority will be stored. When there is only a small flow into the dam, all of the inflow will be released. This is in contrast to the current arrangement where a constant volume is released from the dam each day regardless of the inflow to the dam. The environmental benefits of implementing the reco mmended environmental flow regimes are graphically summarised in the 2004 Metropolitan Water Plan and come at a cost of a fu rther reduction in system yield by 127 GL/yr (H NRMF, 2004). This is because more water would need to be released from the dams than under the current arrangement.

The HNRMF's report includes recommendations on how to supply the required water through a range of measures such as altering water transfer rules, reducing system reliability, reducing demand and by improving access to stored water. Implementing all of these recommendations, including the environmental flow regime, would result in a system yield of 574 GL/yr. Extraction of river water for agricultural irrigatio n and town water supply downstream of Warragamba Dam reduces the river fl ow, particularly at low fl ow periods. T he Penrith Lakes Corporation has been granted a 26 GL/yr extraction licence which allows the extraction of river water when the fl ow over Penrith Wei r is above 170 ML/d. When the scheme is implemented, the extracted water will be used to top up and fl ush out the Penrith Lakes. This highlights that the river system will need to be managed appropriately so that there is sufficient water available for all river users and to ensure that the environmental flows are adequately protected so that they will achieve their goal of improving the river health. The H NRMF recommended specific measures to be taken to achieve this such as modification to weirs and legislative changes. Another key outcome from the H NRMF was a greater understanding of the impact of the d ischarge of tertiary treated effluent on the river system. Sydney Water's sewage treatment plants that d ischarge to the Hawkesbury-Nepean River employ activated sludge secondary treatment followed by sand filtration and d isinfection.


The effluent is of a relatively high quality, even by world standards. However ic still co ntains concentrations of nutrients, such as a coral nitrogen concentration of around 5 mg/L, which are larger than is ideal for river water. The Statement of Joint Intent for the Hawkesbury-Nepean River System sets the target total ni crogen concentration for in-stream water quality at 0.5 mg/L, an order of magnitude less than what is discharged from the tertiary treatment plants. Routine monitoring of the water quality in Warragamba Dam gives a coral nitrogen concentration of around 0.23 mg/L at a point 300 m upstream of the dam wall (Sydney Catchment Authority, 2003).

Ir is noted char total nitrogen is only one of a suite of water quality parameters. However chis simple analysis indicates char whilst the tertiary effluent is high q uality, ic has relatively high concentrations of nutrients compared to natural river water. High nutrient concentrations can lead to eutroph icacion, particularly when there is low river flow , wh ich develops algal bloom s and triggers the excessive growth of aquat ic weeds.

Recycling Opportunities and Issues The issues discussed above p rovide opportunities for a range of innovative recycling schemes. Each recycling scheme is unique and has its own sec of issues that need co be managed. The following summary provides an overview of the various recycling schem es that could possibly be implemented in Sydney.

The increased water demands of che fu ture population growth will be mitigated, in part, by the introduction of the Build ing Sustainability Index (BASIX) which mandates reductions in green house gas emissions and water usage for all new residential dwell ings. T h is requires new homes to be equipped with water efficient appliances and to implement either recycling of treated effluent, via a dual reticulation system, or harvesting of rainwater. Sydney Water plans to extend the Rouse Hill Recycled Water Area Project and to implement a similar scheme in the H oxcon Park development area. T he government has annou nced (NSW Government, 2005) that the 100,000 new homes planned for the south west secto r and the 60,000 new homes in the north west sector will be provided with recycled water through large scale dual reticulation systems. The recycled water would be used at homes fo r a range of uses including toiler flushing ,

NOVEMBER 2006

REC...-CLEDWATER N'TWM

Figure 4. Western Sydney Recycli ng Initiative.

gardening, ca r washing and possibly in the washing mach ine. Issues with dual reticulation systems include the cost of installing the add itional pipework, management of the risk of cross connect ions, and seasonal variability in the demand for water, particu larly for outdoor uses in su m m er. Another po tential issue which would require long term monitoring is the risk of soil salinity as the salt content of the recycled water typ ically is around five times higher than Sydney's dri nking water. Dual reticulation systems are typically only feasible for new developments where che additional pipework can be installed at the same time as the traditional potable water and sewer mains.

Environmental flows

Dual reticulation

44

WHTEPN SYDNEY

Water

T he Metropolitan Water Plan (NSW Government, 2006 b) o utlines the government's two stage p lan co implem ent environmental flows for the H awkesb u ryNepean River. E nvironm ental fl ows would be im p lemented for the U pper Nepean Dams in 2010 and a decision made for Warragamba Dam by 20 15. It has been identified chat appropriately treated efflu ent could be released to the river as a substitute for the release of dam water for environmental flows (SKM, 2003 a). This would reduce the volume of dam water chat needs to be released fo r any given environmental flow and hence leaves more water in the dam for consumption. T he treated effluent would effectively b e recycled for environmental purpo ses. To achieve the targeted environmental benefits, a number of issues would need to be addressed: • Recycled Water Quality: The recycled water would need to be appropriately treated so it is of an accep table quality

Journal of the Australian Water Association

comparable to natural river water. There are a number of sewage treatment plants chat currently discharge high quality tertiary effluent into the Hawkesbury Nepean River. Ir would be necessary co further treat the tertiary efflue n t, through advanced processes such as reverse osmosis, to produce recycled water that has an acceptable quality. • Recycled Water Volume: The recycled water would need co be released to che Hawkesbury River at a flow rate and flow pattern that delivers enviro nmental benefits. As the future environ mental flow regime aims to m im ic the natural variability in river flow, the volume of recycled water released would n eed co vary on a daily basis and hence som e storage is likely co be required (SKM, 2003 a). • Locatio n of Release: The recycled water would need co be transferred co a suitable location in the river system such as co Pen rith W eir or downstream of War ragamba D am at W arragamba Ju nction.

Penrith Lakes Th e Pen rith Lakes Scheme prese nts an opportunity for recycling. Recycled effluent can be used to maintain the lakes and reduce the reliance on river extraction (S KM , 2002). Recycled water q uality is a key issue for recycling co Penrith Lakes as the lakes may be used for recreational purposes. Tertiary effl uent would need to be further created, possibly through a natural wetlands syste m, co maintain acceptable water quality in the lakes.

Agricultural irrigation Numerous studies have been undertaken on the use of treated effluent for agricultural irrigation. The flood plains near Rich mond - Windsor have been identified as a suitable location for recycli ng o f created


effluent for agricultural irrigation (Institute for Sustainable Futures, 2003). The Northern Shoalhaven Reclaimed Effluent Management Scheme is an example of a large scale agricultural irrigation scheme which uses recycled effluent from a number of sewage treatment plants. Sydney Water is curren tly constructing a recycled water pipeline to supply treated effluent from West Camden sewage treatment plant for irrigation of the Elizabeth Macarthur Agricultural Institute. Issues with recycling for agriculrural irrigation include soil salinity, the large variability in seasonal demand, fund ing arrangements and acceptance by farmers, and even the long term viability of the agricul tural land in the face of continual urban expansion. Where potable water is cu rren tly used for irrigation, such as at a number of market gardens, recycling of highly created effluent will save potable water. However these represent a minority of irrigators. The large scale irrigators source their irrigation water from onsite dams and extraction of river water. I t should be noted that water is not released from Warragamba Dam specifically fo r

agricultural irrigation. Hence using treated effluent for irrigation does not directly deliver savings of potable water. However it does deliver environmental benefits by reducing the volume of river water that is extracted.

Indirect potable recycling Indirect potable recycling to either Warragamba Dam or Prospect Reservoir was identified as a possible op tion during the HNRMF investigations (SKM, 2003 a). A comprehensive review of the public health issues associated with potable recycling was also undertaken (SK.M, 2003 b) with reference to existing potable recycling schemes and the recent research on pathogens and compounds of concern. It was concl uded that indirect potable recycling was feas ible and that recycling to Prospect Reservoir was cheaper and required less energy for pumping. However, the report identified that public concerns may favou r recycling to Warragamba Dam where the large volume of the dam would provide greater residence time. However the energy requirements for pumping to Warragamba Dam are sign ificant and may approach

that of sea water desalinatio n depending on the discharge location and transfer route. T here has been renewed interest in indirect potable recycl ing with towns such as Toowoomba and Goulburn undertaking investigations, and there have been renewed calls fo r indirect potable recycling in Sydney as an alternative to sea water desalination (Total Environment Centre, 2005). However, in a past media release the government has ruled our the use of recycled water for potable uses in Sydney (Premier ofNSW, 2005) and with the negative response from the July 200 6 Toowoomba referendum acceptance by the community and government may not change for some time.

Overview The 2006 Metropolitan Water Plan (NSW Government, 2006 b) includes a schematic of a potential recycling scheme, referred to as the Western Sydney Recycling Initiative, which involves a network of pipes sourcing tertiary treated efAuent from a number of sewage treatment plants for recycling to agriculture, households and to the river

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46

NOVEMBER 2006

Water

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Journal of the Australian Water Association


for environmental flows. Figure 4 provides further information on the Western Sydney Recycling Initiative and is taken from the February 2006 Progress Report (NSW Government, 2006 a) .

provide similar benefits. This would include recycling fo r environmental flows if the recycled water is of a sufficient high quality, particularly with regards to the nutrient concenrrations.

Figure 4 illustrates the government's plan for the Sydney's west which includes a nerwork of pipes to collect tertiary treated effluent from a number of sewage treatment plants. The tertiary treated effluent would be recycled to new residences through large scale d ual reticulation systems and recycled to agricultural areas along the banks of the Hawkesbury-Nepean River. Advanced water treatment plants would be constructed to further treat tertiary effluent which would then be d irected to Warragamba Junction and Penrith where it would be recycled for environmental flows. A new sewage treatment plant and advanced treatment plant would be constructed to service the south west release area. Sydney Water is worki ng with the private sector to implement this scheme.

It is noted that the HNRMF recommended that the second option be adopted, which essentially includes a combination of environmental fl ows and efflu ent recycling and as previously stated would reduce the system yield by 127 GL/yr. The HNRMF identified a number of measures that would increase the system yield by 101 GL/yr and hence the net impact of implementing all of the HNRMF recommendations is a reduction in system yield to 574 GL/yr (HNRMF, 2004) . It is noted that this doesn't include any allowance for future climate change.

Recycling and the environment A key impediment to recycling is cost, as producing and transporting recycled water is typically more expensive than using potable water from the existing nerwork. H owever recycling provides a number of benefits that are difficult to quantify in do llar terms. In particular, the work undertaken by the HNRMF identified that reducing the volume of tertiary treated effluent that is discharged to the river system reduces the amount of nutrients in the river and results in improved river water quality. The HNRMF identified that to achieve the desired river water quality there were rwo comparable options: • The first option involved the co ntinued discharge of tertiary treated efflu ent to the Hawkesbury River but required the release of a large volume of dam water to dilute the nutrients. • The second option involved recycling the tertiary treated effluent from fo ur selected sewage treatment plants (St Marys, Quakers Hill, Riverstone and West Camden with a total discharge of 39 GL/yr) and this option required the release of 37 GL/yr less dam water than the first option. Recycling the tertiary effluent from the selected sewage treatment plants reduces the nutrients discharged to the river and this can save 37 GL/yr of dam water from having to be released to achieve the same environmental benefit. W hilst the HNRMF adopted an agricultural recycling scheme, recycling the effluent in any form that effectively prevents the nutrients from being discharged to the environment will 48 NOVEMBER 2006

water

Based on the work undertaken by the HNRMF it can be argued that a recycl ing scheme that reduces the volume of tertiary effluent that is discharged to the H awkesbury-Nepean River delivers not only the benefits of that particular recycling scheme, but in addit ion delivers significant environmental benefits which otherwise would require the release of additional dam water. T he environmental benefits achieved by reducing the volume of effluent discharged to the river, and hence reducing the amount of nutrients discharged, is a large driver for promoting recycling, even where the straight financial cost for the project is not attractive.

Conclusion Sydney's water supply is under increasing pressure due to population growth and environmental impacts. There is a range of recycling schemes possible in Sydney, each with its own benefits and issues that need to be managed . A solution that incorporates a balanced combination of recycling schemes is currently being investigated by the NSW Government. The city's water cycle is also having a detrimental impact on the HawkesburyNepean River which requires the release of environmental flows from the existing dams to protect river health. Effluent recycling schemes that reduce the amount of effluent discharged to the river can deliver significant environmental benefits in terms of improved river health. This can reduce the amount of dam water that has to be released to achieve the same river health outcome. However this benefit is only realised if the environmental impacts of Sydney's water cycle are taken into consideration during any analysis of water supply options.

Journal of the Australian Water Association

The Authors

Philip Von Huben (PVonHuben@ skm.com.au ) and Dennis Cho (DCho@ skm.com.au) are process engineers with Sinclair Knight Merz in the Water and Environment Business Unit.

References Bureau of Meteorology, daily rainfall data for station 068062 (Wanganderry). CSIRO (2004), Climate Change in NSW Part 2:

Projected changes in climate excremes. DIPNR (2004) , Mecropolitan Water Plan:

Meeting the Challenges - Securing Sydney's Water Future, Department of Infrastructure, Planning and Natural Resources. ISBN: 0 7347 5550 3 (print version), 0 7347555 1 1 (web version). HNRMF (2004), Water and Sydney's Future, Hawkesbury-Nepean River Management Forum. Department of Infrastructure, Planning and Natural Resources. ISBN: 0 7347 5456 6. Institute for Sustainable Futures (2003),

Maintaining Rural Effluent Demand Reliability: Issues and Options Paper. NSW Government (2005), Preliminary

Inftascructure Report for the North West and South West Growth Cencres. NSW Government (2006 a), February 2006

Progress Report Metropolitan Water Plan. NSW Government (2006 b), 2006 Mecropolitan Water Plan, ISBNs: 0 73 13 5454 0 (print version), 0 7313 3268 7 (web version). PENGOs (2003), 4th Sydney Water Project Sydney's Water Going to Waste?, Peak Environment Non-Government Organisations. Premier ofNSW (2005) , 29th November 2005 News Release. SKM (2003 a), Potential Uses ofSewage Effluent. SKM (2003 b), Issues Associated with Potable Use

ofSewage Effluent. SKM (2002) , Sewage Treatment Plant Effluents

Options for Improvements in Quality and Indicative Costs. Statement of Joint Intent For the Hawkesbury Nepean River System - Integrated Effluent Management Strategy, August 2003 Sydney Catchment Authoriry (2003), Water

Quality Monitoring Report 2002-2003. Sydney Water Corporation (2004), 2004

Annual Report. Toca! Environment Centre (2005), The

Sustainable Alternative to Desalination. Water Board (1992), Water Reclamation and

Reuse - Reuse Market Analysis.

Web Based References Sydney Water: http://www.sydneywater.com.au/ Pub!ications/_download .cfm?DownloadFile= FactSheets/Weel<lyDamLevels.pdf Water for Life: http://www.wacerforlife.nsw.gov.au


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fereed paper

ROLE OF COMMUNITY PARTICIPATION AND PARTNERSH-IPS: THE VIRGINIA PIPELINE SCHEME G B Keremane, J McKay Abstract The V irginia Pipeline Scheme in Adelaide is one of the largest high quality water recycling schemes in the world and the firs t of irs type in Australia. This paper focuses on this scheme and illustrates the role of community participation and partnersh ips in successful implementation of the scheme. It also looks at the role o f the initial developers and the factors, which created this public partnership, and the current perceptio ns of the present day users of the scheme.

Introduction I n a situation where competition for high quality freshwater is manifo ld, reclaimed water is increasingly being recognised as a new and reliable water source, without compromising public health. Nevertheless, while develo ping successful and sustainable wastewater irrigation schemes, water managers, planners, and policymakers often encou nter difficulties, particularly management problems. Management problems arise d ue to coordinatio n complexity resulting fro m varying roles and responsibilities and overlapping concerns among the public agen cies managing the resou rces (MacD o nald and D yack 2004) . Sim ilarly, wastewater collection , treatment, and its usage span a wide range of interests at different levels of admi nistration. Therefore, the success and long-term sustainability of any reuse scheme largely depends on the institutional organ isation, enhanced community participation, and well-designed partnerships. The paper illustrates the role of commun ity participation and partnerships in developing a successfu l and sustainable reuse scheme. Ir also looks at the factors that created this parrnership, and the perceptions of the present day users of reclaimed water in the Virgin ia Irrigation Area, South Australia.

Background Overuse of the groundwater resources to irrigate the horticultural crops resulted in

50

NOVEMBER 2006

Water

Enhanced community participation and welldesigned partnerships led to success. the decline of water levels in t he aq uifers of the no rthern Ad elaide plains. Each year groundwater resources provides abo ut 1418 GL of water for irrigation in the Virgi nia region which is beyond the sustainable limits of supply (Kracman et al. 200 1; Pritchard and Richardson, 200 5) . In order to supplement the declining groundwater supplies, p rior to the Virginia Pipeline Scheme, many growers used Class 'C' reclaimed water to irrigate their cro ps by pump ing from the Bolivar wastewater treatment p lant o ur-fall channel. Growers were thus aware of the potential th is new source had to offer towards meeting the growing demand for water supplies. This realisation by the growers and driven by the environmental, econ omic and social factors has led to the commissio ning of the Virginia Pipeline Scheme (VPS) in 1999 (Kelly and Stevens, 2000; Thomas 200 6).

Journal of the Australian Water Association

Since then, the VPS has provided reclaimed water for irrigation in the No rthern Adelaide plains, some 35 kms north of Adelaide. Ir supplies highly treated reclaimed water to approximately 25 0 growers operating within an area of 200 square kilometres. The p roposal for develop ing the V PS was visualised when SA Water, as part o f its Environment Improvement Program, constructed a $30 million fi ltration/disinfection plant (DAFF) to treat effluen t from the Bolivar wastewater treatment p lant, pro ducing C lass A reclaimed water that could be used for irrigation in the region. The Water Reticu lation Services Virginia (WRSV), a private company, gained a contract to access the output from the treat ment plant, and fu rther signed up clients for the water and bui lt the water d istribution system. Th us, VPS is a co-operative undertaking of SA Water, Water Reticulation Systems Virgin ia (WRSV) - a p rivate company and the Virgin ia Irrigation Association (VIA) representing market gardeners and ocher irrigators. Figure 1 p rovides the schematic layout of the V PS and its distri bution network.


The Study The design adopted for this study was 'Case Study', a research strategy that focuses on understanding the dynamics present within single settings (Eisenhardt, 1989). Household interviews were conducted to gather information and key informant interviews augmented the information. Structured questionnaires were used for the household interviews using a mix of question types: multiple choices, numeric open end, and agreement scales. An initial exploration survey revealed chat the irrigators associated with VPS comprised Greek, Italian, Australian, Vietnamese, and Cambodian communities. In order to interview irrigators with non-English speaking background, interpreters were recruited on the bases of command over Vietnamese, Khmer and English language, as well as relevant knowledge of the survey methods and study theme. In addition, the questionnaire was translated from English into Vietnamese and Khmer by professional translators to facilitate the interview process and in some cases, allow che respondents to mark che document on their own. When the WRSV was approached for che list of irrigators associated with the VPS, it was difficult to obtain the list because of some formal obligations of the water company. Therefore, a snowball sampli ng technique was employed to identify che respondents who were using reclaimed water from the scheme. In total 165 farms were visited out of which 128 irrigators responded. This accounted for around 51 per cent of the to cal number of irrigators associated with VPS (Table 1). Those not responding were either not interested in the study or not available during the repeated visits made to their farms. Simple tabular analysis with aid of frequencies and percentages was used to arrive at the results.

-=-- t

t

........

.

s••.,••

Source: Modified from Radcliffe, 2004 Note: Figure not to scale

Figure 1. Layout o f the Virginia Pipeline Scheme a nd its distribution network . virtually all irrigators, the irrigators tend to fo rm a corporate body to deal with common irrigation and cultivation problems. The individual not only gees an identity but also security in the process of collective action". That was the case with the inception ofVPS where people organised collectively in o rder to find solution to che water scarcity crisis in che region caused by depleting groundwater resources (Kracman, 2001; Thomas, 200 6).

facto rs prompted the partnerships or motivated the growers for collective action? Generally, whenever individuals face problems unsolvable on their own chey tend co come together to find solutions. This means, when there is a widely acknowledged crisis i.e. a crisis that multiple groups acknowledge as affecting their core interests; collective action is possible (OECD, 200 3) . Collective action therefore becomes an immediate necessity rather than a choice. According to Wade (1979), "where water is problematic for

Respondents were asked to mention the most important reason chat prompted

Table 1. Distribution of the respondents across different ethnic groups. Group

Non-English speaking English speaking Total

Toto! number of farms visited

Total Respondents

120 45 165 (65)

91 37 128 (51)

Note: Figures in parentheses ore percentages of the total number /252) of irrigators using reclaimed water.

Results and Discussion According ro Agarwal and Ostrom (1999), through collective action, enhanced community participation, and welldesigned partnerships, ic is possible co coordinate individual's activities; develop rules for resource use; sanction violators and mobilise the necessary cash, labour, or material resources. T his study attempts co capture the perceptions of present day users' about community participation, collective action and partnerships along wi ch the factors responsible for implementing the VPS.

Factors prompting implementation of the scheme As mentioned earlier, VPS is the result of collective efforts and partnerships. So, what 52 NOVEMBE R 2006

Water

D Groundwater depletion

• 1-igh price of rmins water

a Encouragement by water authorlies

• Comrunity interest

a R-ior experience using reclaimed water

Figure 2. lrrigators' perception of reasons promptin g development of the VPS .

Journal of the Australian Water Association


efereed paper

development of the Virginia pipeline. Figure 2 illustrates their responses. Around 53 per cent of the respondents reported groundwater depletion as the most important reason followed by 32 per cent quoting the price of che mains water. Around seven per cent believed that community interest ro use reclaimed water for irrigation was the importan t reason. About six per cent rated encouragement by water authorities as rhe important reason. However, these are only the irrigarors' perception. Apart from the fa ctors perceived by the respondents, increasing p ublic concerns about the environmental damages caused by d ischarge of highly nu trient rich effiuents into the ocean accompanied by some government initiatives such as Build ing Beerer Cities were also instrumen tal.

The theory of collective action Collective action is mostly discussed in relation ro che 'tragedy of the co mmo ns' (Hardin,1968) and much of the world is dependent upon resources chat are subj ect ro che possibility of a tragedy of the co mmons (Ostrom 1992). Although, overcoming rhe tragedy of the commons is nor an easy task, there is a growing consen sus among commons scholars chat collective, co mmunity- based regulation holds out rhe b est prospects for efficient management of resources (Ostrom 2000). The co ncept of collective action has, therefore, emerged as a respo nse ro deal with the tragedy of the commons. The phrase 'co llective action' refers to activi ties that require the coordination of efforts by rwo or more individuals (Agarwal and O strom 1999). Individuals associate themselves for a collective action with an obj ective ro face rhe uncertainties and to search for solutions wherever possible. T he commons literature has ample evidences of collective regulation for natural resources management (Whi te and Runge 1995; Lam 1996; O strom 1992; 2000). The study used 11-point Liken scale items as a measure of collective actio n and cooperation within the community. To assess the irrigarors' perception regarding collective action and also participation, respondents were asked ro agree o r disagree with the scale items and the results are presented in Table 2 and Table 3. More than 75 per cent of the respondents agreed char 'most people in the community are will ing to help when in need'. When asked about their perception on communi ty prosperity over the last five years, around 76 per cent believed that the community has prospered b ecause of cooperation among the community members. Keeping

Table 2. lrrigators' perception about collective action and cooperation. Statements

Agree

Neutral

Disagree

People in the community will cooperate when there is water supply problem

75 (59)

18 (14)

35 (27)

Most people in the community are willing to help when in need

101 (79)

23 (18)

This community has prospered in the last live years

97 (76)

28 (22)

I feel accepted as a member of this community

99 (77)

26 (20)

4 (3) 3 (2) 3 (2)

Note: Figures in parentheses are percentage of the total sample {N= 128). in mind the variations in cultural background and eth nicities, the respondents were asked if they felt accepted as a member of one community. More than 7 0 per cent agreed rhac they felt accepted. It was observed during the survey that most of the respondents were engaged in farming in Virginia for more than 10 years without any problems. T h is supports the perception of irrigarors' char rhey fel t accepted by the community. When specifically asked about cooperating during a water crisis, about 59 per cent agreed that people cooperate in such situations. A considerable percentage of people remained neutral (marked five o n the scale) in response ro chis proposition. As observed during rhe survey, one possible reason for this could be char most respondents were new ro che scheme. O verall , the responses and observations made during the survey imply char the community has a strong sense of cooperation and is community orien tated. Mere presence of a crisis does not always bring out collective actio n, participation of all the actors involved is equally important. Participation is a broad term with many variations in its meaning and interpretation. However, in its narrowest sense, participation can be defi ned in terms of nominal membership, wh ile in the broadest sense it can be defined as a process in wh ich people voice and influence in decisionmaking (White 1996). Here, che focus is 'community participatio n' and ro examine rhe extent of community participation the study proposed three statements ro rhe irrigarors (Table 3). Respondents, when asked if they worked with ochers for the benefit of the

community, almost 60 per cent agreed with the proposition. When asked whether people who do not participate in communal activities are criticised, more than 60 per cent disagreed with the proposition. About making fa ir contrib ution cowards communal activities around 42 per cent of the respondents though t char everyone in the co mmunity makes a fair contri bu tion. The term 'contribution' here meant contribu ting in terms of money o r kind. Almost an equal percentage of respondents remained neutral. Around 75 per cent of the respondents agreed that the community has prospered in the lase five years. C hi-square (X2) estimates were calculated ro rest wheth er irrigarors' percep tion about collective action and participation varied with age, education level, o r ethnicity. The estimates were nor significant affirming rh ac irrigarors' percep tion was similar across di ffere n t age group, education level, and eth nicity.

Trust and solidarity Ir is evident from the success of the scheme chat despite different eth nicity and cultural backgrounds the irrigarors have d emonstrated a high degree of networking. Absence of th is would have raised problems. This is in contrast ro the argument regard ing co llective action that division of irrigarors by cultural and/or other social differences affects their capacity ro communicate with one another (Tang, 1992). Therefore, the findings of this study while contradicting previous studies suggest that relatively heterogeneous community groups can be effective at provision of irrigatio n services (Kurian and Dietz,

Table 3. lrrigators' perception about statements regarding participation. Statements

Agree

Neutral

Disagree

I have worked with others in the past for the benefit of the community

76 (59)

40 (31)

12 (9)

Most likely, the people who do not participate in communal activities are criticised.

14 (11)

34 (27)

80 (63)

Everyone in the community makes a lair contribution to communol activities

54 (42)

53 (41)

21 (16)

Note: Figures in parentheses are percentage of the total sample (N= 128)

Journal of the Australian Water Association

water

NOVEMBER 2006 53


2005). This also demonstrates a high level of cruse among the members of the community. Further, since d ifferent agencies are involved in che fu nctioning of the VPS, crust in these agencies also plays an impo rtant role in decid ing about participation in the scheme. Respondents were asked about their level of trust in the agencies- governmen t, EPA, health services and che water company. Figure 3 depicts the level of crust irrigacors have in various agencies. lrrigators had either complete crust or some level o f trust in these agencies co perform their duties effectively. Arou nd 58 per cent of the responden ts had complete trust in the government agencies while another 16 per cen t had some level of trust. Regard ing the water company, more than 55 per cent had complete trust while around 26 per cent more had some level of crust. About crust in o ther associated agencies like the EPA and che Health department, more than 40 per cent had complete trust. H owever, percentage o f respondents who were indifferent is consid erable, particularly with respect co EPA and Department of H ealch. This may be d ue the lack of awareness amo ng che irrigacors regarding che role of these agencies in relation co the scheme. T he chi-square estimates for age group (X 2=18.11) and ethn icity (X 2 =41.78) in case of trust in water company were significant implying that irrigators' with English speaking background and in the young and middle age groups had more trust. Similar results were obtained in case of trust in the health department where the estimates for age (X 2=23.82) and ethnic groups (x2 =7 1.32) were significant, implying English speaking background and you ng -mid dle age groups had more trust in the health d epartmen t.

Partnerships Apart from collective action and commun ity participat ion, 'well designed public-p rivate partnerships' is also a factor responsible fo r che success and sustainability ofVPS.

In the context of water sector, publicprivate partnerships refer co 'public entity entering into a contractual agreemen t with the private sector co take over some or all of its activities related co water management' (OECD 2003). Generally, public-private partnerships (PPPs) promoted within the water sector are concessio n-based contracts in which a private fi rm obtains fro m che government che right to provide a particular service u nder cond itio ns of significant market

54

NOVEMBER 2006

Water

...en0

..

100 90

('Q

CJ)

¡;::

80

C: Cl

60

-.. ¡=0

...

70

(.)

Cl

C.

.;..;

..-... en

:I

0

'ii >

Cl

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50 40 30 20 10 0 Go..t.agencies

EPA

Water Company

Health services

Agencies a Complete trust c Some trust a No trust a Indifferent

Figure 3. lrrigator's level of trust in di fferent agencies associated with the scheme.

power (Kerf et al. 1995 cited in Braadbaart 200 5) . Such contracts come in th ree families namely: franchise contracts, concession contracts and the build -operatetransfer (BOT) contracts (Braadbaart, 2005) . T he Virginia pipeline is built o n the BOT model. Under t he BOT fo rm of partnership, capital investmen t, designing, building and operating the scheme is the responsibility of the private sector while the responsibility of setting perfo rmance standards, asset ownership, user fee collection, and oversight of performance and fees rests with the public agencies. This means, "in a BOT project, a private company is given concession to build and operate a facility chat would normally be built and operated by the government" (UNIDO, 1996 cited in Braadbaart 20 05). In che present case, SA water (p ublic agency) is responsible fo r setting performance standards, asset ownership, user fee collection and, oversight of performance and fees. T he WRSV (private company) is responsible for capital investment, designing and build ing and operating the scheme. H owever, it had some fi nancial assistance fro m the SA water and Federal government fu nds from the Build Better Cities Program .

Impediments encountering implementation of reuse scheme Successful development of reuse schemes always encounters various imped iments. M ost o f these are due co lack of institutional organisation and commu nity reluctance co use this resource. Legal, policy, institutional and social impediments occupy a prominent place during the

Journal of the Australian Water Association

implementation of any reclaimed water irrigation schemes. Acquiring fu nds is another important obstacle since fi nancing a reuse scheme is normally a complex cask. Legal and policy issues were addressed effectively because South Australia has a favourable regulatory and policy regime for wastewater reuse. T he government policy 'co phase out all sewerage discharges to che marine environment where it is eco no mically and environ mentally sustainable' has significantly in fl uenced che develop ment of water reuse programs in South Australia (Th iyagarajah 20 05). T he inclusion of reclaimed water in the South Australian Governmen t's State Water Plan 200 0 demonstrates t he State's commi tment co wastewater reuse projects. Above all, the state has several regulatory controls that need to be complied with befo re implementation of the scheme like comp rehensive reclaimed water guidelines; Water Resources Act; approval of che Public and Environmental H ealth Service, and approval of Envi ronment Protection Authority (EPA) . The remaining fi nancial, institutional and social issues were add ressed through cont ractual agreements between the stakeho lders - SA Water, VIA, and the WRSV. As a pare of the contractual agreemen t, SA water constructed che D AFF water treatment plant. The WRSV built the d istribution system and delivers water to dams on individual growers' properties, fro m which they p ump the water into their own irrigation systems. T he supply contracts with the irrigarors are with the water company who owns the scheme at present and will transfer the whole scheme


to SA Water in 20 18 as per the terms of agreement (Menzies, 2001).

In the present case, Government agencies contributed nearly half the capital funds. The total cost of the project ($55mill ion), including the DAFF Plant and the reticulation system, was shared between the Commonwealth Government ($ 10.8 million), which contributed fro m the Building Better Cities fu nds, Landcare ($574,000), private investors ($7 million), SA government ($7 million), Horticulture Australia Limited ($ 700,000) and the remainder from SA Water. Regarding the social issues, which is moscly add ressing the community co ncerns about using reclaimed water the VPS has clear and effective water management plans. An Irrigation Management Plan (IMP) is developed by the WRSV to ensure chat the irrigation of the agricultural land is sustainable. T he Environment Protection Agency (EPA) is responsible for approving and reviewing the IMPs on an annual basis and ensuring chat it complies with ail the environmental legislations. T he irrigation association (VIA) representing the commu nicy/irrigators manages an education programme for growers in relation to water reuse. This programme aims to educate the irrigators about the impact of rhe enhanced nutrient levels on so ils and natural groundwater by use of reclaimed water. Ir also closely moni tors the effects of the reclaimed water on the soils. To inform the public, all properties using reclaimed water have signs on fenci ng reading 'Reclaimed water - do nor dri nk'.

Conclusions Development of successfu l and sustainable water reuse projects wi ll defin itely provide solutions co water scarcity problems. H owever, we cannot overlook the impediments encounteri ng implementation of any reuse scheme. Experiences fro m the VPS suggest chat co mmuni ty participation, well-designed partnerships, and favo urable regulatory and policy regime are ve1y much important in implementing a successful and sustainable reuse scheme. Further, by provid ing knowledge and info rmation on the current best practices and communicating this inform ation in a form

that is understandable co the different stakeholder groups, it is possible to implement sustainable reuse schemes.

Acknowledgments T he authors express their grati tude cowards the University of South Australia and CRC for Irrigation Futures (CRC IF) fo r supporting chis work. The authors thank Bui, Huynh Thanh Nguyen; Le, Thi Thanh Tra; Nguyen, Van T uong; Pham, Th u Van and Chy, Ty fo r their help in translation and conducting the survey. T he authors thank Satya G. N . fo r helping create the map and fin ally the participants fo r thei r time and cooperation.

The Authors Ganesh 8. Keremane is a PhD student at the University of South Australia. He is a President's Scholarship holder and CRC for Irrigation Futures Scholar and chis paper is based on his PhD research work. Email: ganesh.keremane@unisa.edu.au. Jennifer McKay is Professor of Business Law and Director of the Centre for Comparative Water Policies and Laws, University of South Australia. Email: Jennifer.Mckay@unisa.edu.au

References Agarwal, A. and Ostrom, E ( 1999) Collective action, property rights, and devolution of fo rest and protected area management. Paper presented at Workshop on Collective Action,

Property Rights, and Devolution ofNatural Resources Management, Puerro Azul, the Philippines, 21-25 J u ne. Braadbaarr, 0. (2005) Privatizing water and wastewarer in developing countries: assessing the 1990s, experiments. Water Policy, 7: 329344. Eisenhard t, K. M. (1989) Building theories from case study research. The Academy of Management Review, 14(4):532-5 50. Hami lron, A. J., and et al. (2005) Position of the Australian H orricultural Industry wi th Respect to the Use of Reclaimed Water, Agricultural Water Management 71 (3): 181209. Hard in, G. (1968) T he T ragedy of the Commons. Science, 162: 1243- 1248. Kelly, J. and Stevens, D . (2000) From problem ro profi t. Wa ter, 27 (5):39-41. Kracman, B., Marrin, R., and Sztaj nbok, P. (200 l ) The Virgin ia Pipeline: Aust ralia's lasgest water recycling project. Water Science and Technology, 43(1): 35-42.

Kurian, M. and Dietz, T. (2005) H ow pro-poor are participatory watershed management projects? -An Indian case srudy, Research Report 92. International Warer Management lnsriture, Colombo, Sri Lanka. Lam, W . (1996) 'Improving the performance of small-scale irrigation systems: the effects of technological investments and governance structure on irrigation performance in Nepal'. World Development, 24 (8): 1301-1315. MacDonald, D . H. and Dyack, B. (2004) Exploring the institutional impediments to conservation and water reuse - National issues. CSIRO Land and Water Client Report. Menzies, Tom (2001) The$ 52 m model. The Source, April 200 I , Issue 13, pp.9. Organ ization fo r Econom ic Co-operation and Development (2003) Public-Private Partnerships in the U rban Water Secror. OECD Policy Brief, April 2003. Ost rom, E. (1992). Crafting institutions for self governing irrigation systems. !CS press. San Francisco, CA. Ostrom, E. (2000) Reformulating the com mons. Swiss Political Science Review, 6 (I), pp. 2952. Pritchard J . and Richasdson S. (2005) Northern

Adelaide Plains: Analysis oftrends in the groundwater conditions. Research and Environment Management Pry Ltd for North Adelaide and Barossa Catchment Water Management Board, Kent T own, Sourh Australia. Tang, S. Y. ( 1992) Institutions and Collective Action: Self Governance in Irrigation, San Francisco, !CS press. T hiyagarajah, R. A. (2005) Sustainable wastewater reuse through private sector participation - The Adelaide experience [onl ine). ADB. h rrp://www.adb.org/ Documents/Events/2005/ San iration-Wastewater-Management/ paper-thiyagarajah .pdf [accessed 28 March 2006] Thomas, R. (2006) Reuse in South Aust ralia in Daryl Stevens (Ed) Growing crops with reclaimed wastewater, CSIRO Publishing, Victoria, Aust ralia. Wade, H . R. (1979) T he Social Response to Irrigation : an Indian Case Study. journal of Development Studies, 16( 1): 3-26. White, A., T and Ru nge, F. C. (1995) The Emergence and Evolution of Collective Acrion : Lessons from Watershed Management in H aiti. World Development, 23(10): 1683-1698. White, S (1996) Depoliticizing develop ment: T he uses and abuses of participation. Development in Practice, 6(1): 6- 15.

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Journal of the Australian Water Association

Water

AijGl\ V COMPANY

NOVEMBER 2006 55


PEAK PERFORMANCE AND


GREAT TEAMWORK

Kse 6J


fereed paper

MELBOURNE OFFICE WORKER ATTITUDES TO RECYCLED WATER USE A Hurlimann Abstract This paper reports results fro m a stud y of o ffice worker attitudes co recycled water u se. Survey respondents were employees of the C ity of Melbourne, some o f who m will soon be working in che innovative Co uncil House 2 office build ing. Th is building incorporates che use of recycled water th rough 'sewer min ing' activity. Recycled water will be used in the cooling cower system, fo r toilet flushing, street cleaning, and street tree watering in the central business district. This is the fi rst investigatio n of office worker attitudes co recycled water use in Austral ia, thus the results o f chis study are of importance co in form ing the feas ibility of recycled water in such a context in Australia and potentially in ocher pares of the world. Results of chis scudy indicate char recycled water use as incorporated in che Council H ouse 2 building is acceptable co the fucu re occupants. Factors in fluenci ng an individ ual's accep tance of recycled water use were fo u nd co be their beliefs, perceptio ns an d attitudes surround ing cruse in the water authority, in formation provision , risk percep tion, environ mental co ncern, satisfaction, fai rness in implementation , and perceived need co recycled water. There were no d ifferen ces o bserved between demographic groups and acceptance of recycled water use, but ch ere was a difference fou nd with o ccupation. Prior experience of recycled water use was fou nd co positively in fl uence acceptance of recycled water use.

Introduction The use of recycled water is extremely topical in Australia at presen t. le is nor on ly topical fo r engi neers and scientists but researchers beyond che traditional spheres o f engineering and science and importantly che comm un ity, politicians and media (Eccleston 200 6; Turnbull 20 06). Wi th m any major cities and towns in Australia experiencing severe drough t conditions and subsequent restrictions co potable water use, recycled water use is an increasingly sought after management strategy co ease th e 'drough t' (Governmen t of Sou ch Australia 2003; Govern ment of Western Australia 2003; Victorian Government

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NOVEMBER 2006

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Department of Sustainability and Envi ronment 2004). However, in some in stances it has been demonstrated chat the community may nor be willing co use recycled water, in particular for drinking water purposes. T his o pposition co recycled water use for potable purposes was demonstrated in che recent referend u m regard ing water fucures in Toowoomba on 29 J uly 2006, where 6 1.5% of voters opposed che use of recycled water fo r potable purposes (Water Fu tures T oowoo mba 20 06).

Recycled water use as incorporated in the Council House 2 building is acceptable to the future occupants. In Australia there have been a number of studies regard ing co m mu nity attitudes co recycled water use (McKay and Hurlimann 2003; Marks 200 4, M arks et al. 20 06). These studies have indicated that support fo r recycled water use decreases as the use becomes increasingly personal. However, che majori ty of such research into commun ity attitudes to recycled water use has been th rough once-off (cross-sect ional) surveys. A recent long- term study o f th e Mawson Lakes (South Australia) community's atticudes to recycled water ind icates that atti cudes are in a state of fl ux, changing in response co factors such as new infor mation (H urli mann, 20 06). This ind icates che benefit of long-term mo nitoring of attitudes and the facto rs chat may in fluence their change. It is acknow ledged, however, char such longterm mon itoring of attitudes can in duce survey fatigue. Recycled water use in commercial b uildings can contribu te co po table water savings, however there has been limi ted research cond ucted into atticudes of office workers co recycled water use. Research was conducted in Japan in 1999 of occu pants of 125 com mercial b uild ings using recycled water mainly for coilec fl ushing (Yamagata et al. 20 02). Accep tance was strong, buc

Journal of the Australian Water Association

problems with od our of che recycled water were reported . More research is needed in to the factors infl uencing satisfaction with recycled water use in an office environment, particularly in an Australian context.

Study Site The site chosen fo r chis research was the C ity of Melbo urne's (CoM's) innovative Cou ncil House 2 offi ce buildi ng (CH 2) located on che co rner of Swanston and Lierle Collins Streets in the Melbourne Cen tral Business D istrict. The bu ilding construction is nearing completion and che occupation commencement date is an ticipated to be October 2006. It is anticipated the building will achieve significant savings in energy and water use, provid e a h igh q uality indoor environment for office workers and conserve resources in che process of constructio n. In 2005 the G reen Building Cou ncil of Australia award ed CH2 a 'six green star rating' which represents world leadership in office b uild ing design (further detai ls can be fo und at URL http://www.melbo urne.vic. gov.au/ info.c fm ?top=l 7l&pg= 1933). One major intention of the CH 2 bu ilding is effi cient water use. In addition to water effi cient fi xcures and app liances, the design of th e CH 2 build ing includ es a 'sewer mine' . Sewer mining is a p rocess where wastewater is extracted from the sewerage system and created to a very h igh standard to be reused . Abo ut l 0 0 kL of wastewater a day will be extracted from the Swanston Street main d rain (Othman and Jayasu riya 200 6). This sewage, along wich sewage generated on sire, wi ll be created co a standard suitable for all non-potable (nond rinking) uses and will meet all Class A water criteria through a separate water supply system (Othman and Jayasuriya 2006). The recycled water will su pply the C H 2 cooling cower system, plan e watering and toi let fl ushi ng need s and is also intended to be used for street cleaning and street tree watering with in che C BD.

Study Methodology The pu rpose of ch is su rvey was co benchmark attitudes to recycled water use prior to che occupation of the CH 2 build ing. Boch employees who were


~REAT TEAMWORK

Kse GJ l(o;O A1,111 Pump, Pty ltrt


moving into CH2 and those who were nor moving into CH2 were able ro participate in the survey to allow assessment of any differences in responses between the two groups of employees. The su rvey was conducted on-line and served as a rest case for chis relatively new survey approach. Employees of the City of Melbou rne were invited to participate in rhe stud y through an item in an organisation-wide email with an associated web link co th e survey sire. Responses were ano nymous. Two reminder emails were sent o ur and the survey closed within o ne week of rhe init ial survey (9 16 August 2006). O n average, the survey took participants between 5 and 10 mi nutes to complete. A total of 197 CoM employees responded to the survey ou r of an average of 690 employees wh o read these emails (statistics provided by CoM) giving a response race of 28.5% wh ich was considered adequate fo r this study. Analysis of demographic derails of respondents showed a good cross-section of respo ndents. T he context of the recycled water use was made clear with the fo llowing statement at the begin ning of the su rvey: 'At CH2

wastewater {from the sewer system) will be treated to Class A standard. Class A standard recycled water is often better quality than drinking water. However this Class A recycled water will only be used for very limited (nonhuman contact) uses in the CH2 building. ' Respond ents were asked how happy rhey were to use various uses of recycled water includi ng beyond those occurring at CH 2. These were rated on a Likerr (1967) scale of 1 - 10 where I = 'nor at all happy' and IO = 'extremely happy' . An ad dit ional series of attitude and perceptio n statements were also included in rhe study, fo r which resp ondents were asked to rare their agreement on a Like rt scale of 1 - 10 where 1 = 'very st rongly d isagree' and IO = 'very strongly agree' . Respondents were asked a series of q uestions relating to their employment and demographic details (i.e. gender, age, education level). 'Happ iness' was chosen as rhe main operational variable in chis survey. This was a departure from other surveys which have measured variables includi ng acceptance, agreemen t, support, will ingness to use and satisfaction (with recycled water use) . Happiness was chosen for the context of this su rvey, where many respondents wou ld be using recycled water in rhe future as determined by their employer. An important measu re was their happiness to use recycled water in this context. Satisfactio n could nor be measured because they had nor yet had experience with the recycled water at C H 2 .

60

NO VEM BER 2 006

Water

~ s hower

drinking

was h hands recycled \fflter use

clothes washing

I

I I I

I I I

cooling system public fountain s and water features street cleaning

~

5. 0 6. 2

6. 7 6. 9

I

8. 5

I I

I

I

'

I

plants and gardens at ho me

9. 5

I 9. 5

I toilet flus hing

9. 6

I

I

40

60

street trees and gardens Dhappy

8. 8

0

â&#x20AC;˘ very happy

20

9. 7 80

100

percentage res pondents

Figure 1. A ttitudes to various uses of recycled w ater. N ote: Mean va lues on scale of 1 -10 shown on graph. T he survey resu lts were analysed using the Statistical Package fo r the Social Sciences pro gram (SPSS Inc 1997) . In pa rticular, C hi-square rests were conducted at various points of the study to analyse results and establish if there were significa n t d ifferences between groups .

Results and Discussion General results For the purpose o f analysis, responses to questions regarding happiness to various uses of recycled water were transformed from a 10 point scale to three categories 1-5 = not happy, 6-8 = happy, and 9 & 10 = very happy. The percentage of respondents raring the uses of recycled water investigated in the survey as either 'h appy' or 'very happy' is shown in Figure 1, along with rhe mean fo r each use. Results in Figure 1 show that respondents were less happy with water reuse fo r personal use than fo r non-personal use. Responses ranged fro m 47% of respondents 'happy' to use recycled water for dri nki ng purposes (raring this use between 6 and l 0 on the Likert scale) to 99% of respondents 'happy' to use recycled water for watering street trees and gardens. In general, this pattern o f decreasing support for recycled water as the use becomes increasingly personal, follows the pattern o f resul ts fro m other Australian and overseas studies on attitud es to recycled water use (M arks et al. 2006; McKay and Hurl imann 2003; Bruvold 1972) . Respondents were happy wirh rhe fo ur uses of recycled water incorpo rated through the sewer mining activity of C H 2 (watering street trees and gardens, to iler fl ushing, street cleaning and in the cooling rower system). Over 96% of

Journal of the Australian W ater Association

respondents were happy with each of the uses except for co oling tower system, of which on ly 84% of respondents were happy, bur this is still a high percentage. The 47% of respondents in this study happy to use recycled water fo r drinking purposes, could be com pared to resul ts of the Toowoomba referendum where only 38% of residents supported potable water recycling (Water Fut ures T oowoomba, 2006), and to a recent national find ing of confid ence to drink the water (Marks et al.

2006). Comparison of attitudes between those moving into the CH2 building and those not moving in Resul rs fo r all uses of recycled water were compared between ch ose respo ndents who indicated they wou ld be working in C H 2 in the fu ture (59%, n = 117) and chose who indicated they would n or be (36%, n = 70). T h ere was a signi fica nt difference between the groups for o nly o ne use of recycled water, the cooling rower system (signi ficance level = 0.05) . For th is use, 11% of respondents who would be working in C H 2 in the fu ture were nor hap py with recycled water use for this purpose compared to 23% of respondents who wo uld not be working in CH2 in the future. This indicates that respondents who will be working in the CH 2 b uild ing were h ap pier w ith the fact rhar recycled water would be u se in th e cooling system rhan those wh o would nor be working in t he b uild ing. Ir was tho ught rhar information provisio n could be an explanatory variable, as it was assumed th at those wh o would be working in the CH2 bu ild ing in t he fu ture would be more info rmed abo u t th e recycled water u se. Statistical rests were undertaken


Idea: Manage a city's infrastructure from the ground up .


technical features

Table 1. Impact of prior experience on happiness to use recycled water. % Happy to use recycled water for drinking

% Happy to use recycled water to wash hands

% Happy with recycled water use for clothes washing

% Happy with recycled water to shower

Yes% (n)

61 (40)*

75 (52)**

No% (n)

36 (22)

56 (35)

75 (51) ** 57 (35)

70 (48) ** 52 (32)

Prior experience of recycled water

* significant at the 0.01 level, ** significant at the 0.05 level.

any demographic variables investigated (age, education, gender).

to assess the relationship between attitude co information provision and fu ture occupancy of the building. No significant resulc was obtained.

Impact of prior experience of recycled water use Resulcs for all uses of recycled water were compared between chose respondents who indicated rhey had used recycled water before (35%, n = 69) and chose chat indicated they had not used recycled water before (32%, n = 63). An additional 33% (n = 65 respondents) did nor know whether they had used recycled water before. Significant differences between groups were found for che four most 'personal uses' as derailed in Table I. This indicates char experience of recycled water use could facilitate greater acceptance of recycled water use.

Occupational differences Given the distinct differe nce in happiness betwee n drinking water and ocher uses, it was thought useful co investigate some key demographic and attitudinal variables between chose happy, and those not happy co use recycled water use for drinki ng purposes. Recycled water use fo r 'washing hands in an office environment' was also investigated due to its policy implications and potential water saving benefits in an office setting. Additionally, recycled water use in the 'cooling cower system' was investigated because it was the least favoured use of recycled water in the CH 2 context. For all three uses there were no differences in responses between

There was a statistically significant difference in attitudes between occupations and for drinking purposes and washing hands with recycled water (significance level 0.05). These resulcs are detailed in Table 2. The results indicate that respondents with an engineering occupation were the least happy with recycled water use for drinking purposes and washing hands, while respondents in occupations relating co the environment and health were most happy. There was not a significant difference between occupation and attitude co recycled water use for the cooling cower system. The resulcs could suggest that engagement in environmental sustainability issues may raise greater happ iness or tolerance of recycled water use. Engineers in this study were from various specialisations including road and structural, not just water engineers. Given the small number of engineers responding co this survey the results should be viewed with caution. It is unwise co d raw conclusions from such a small sub sample. Further research in this area in the future would be beneficial. These results regarding occupation are contrary to a US study by Sims and D aumann (1976) where 22 state health officials and 98 consulting engineers were interviewed. This study found that public health officers were more opposed co recycled water use than engi neers. H owever, the context of this study was possible public use of 'renovated wastewater' and not personalised as in this study.

Attitude and perception statements For all three uses of recycled water investigated (drinking, washing hands and the cooling cower system) differences between the responses co various attitude and perception statements were investigated. These attitude and perception statements relate co: trust in the water authority, fairness in the implementation of recycled water use, satisfaction with recycled water use at CH 2, attitude cowards the environment, information provision, perceived health risk and perceived need co recycled water. The responses on the 10 point attitude scales were transformed inco 2 categories, 1 - 5 = disagree and 6 - 10 = agree. These results are presented in Table 3. Despite nor yet in use it was thought beneficial to investigate the impact of perceptions of fairness in the implementation of the recycled water use co dare. This was shown in a previous study co be an important component on acceptance and satisfaction with recycled water use (Hurlimann 2006) and is well supported in parallel literatures such as marketing. Additionally, tests of correlation between each of the attitude and perception statements (as listed in Table 3) were undertaken. All but three were significantly correlated at the 0.01 level. The three nonsignificant correlations were all with the statement 'I am concerned about environmental problems'. They were: 'I am well informed about recycled water use at CH/, 'I am satisfied with recycled water use as it will occur at CH 2' and 'recycled water use at CH2 has been implemented in a fair manner.'

Table 2. Attitude to recycled water use for drinking and washing hands - differences between respondent occupation. Administrative

IT/Business

Engineer

OCCUPATION Environment/Health

Town Planning/Design

Social/Community

35 37.1% (13) 62.9% (22)

73 43.8% (32) 56.2% (41)

16 31.3% (5) 68.8% (11)

20 80% (16) 20% (4)

27 51.9% (14) 48.1% (13)

20 50% (10) 50% (10)

36 52 .8% (19) 47.2% (17)

73 67.1% (49) 32.9% (24)

17 41 .2% (7) 58.8% (10)

20 80% (16) 20% (4)

27 77.8% (21) 22.2% (6)

21 76.2% (16) 23.8% (5)

DRINKING

N Happy% (n) Not Happy % (n) WASHING HANDS

N Happy% (n) Not Happy % (n)

62 NOVEMBER 2006

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Journal of the Australian Water Association


Table 3. Attitudinal influence on happiness to use recycled water use for drinking, washing hands a nd in cooli ng systems (n=l97). Overall response % Happy to use recycled water for drinking to statement (%)

Attitude/perception statement

% Happy to use recycled

% Happy with recycled water

water lo wash hands

use in the cooling system

I am concerned about environmental problems

96 4

48** 13

68*** 13

85 63

50 49

59*** 34

74** 58

93*** 75

74 26

53*** 27

73*** 46

93*** 59

65 34

57*** 25

72* 53

92*** 67

75 24

56*** 16

74*

9 1*** 60

Agree

95 4

69*** 11

86***

Disagree

48 22

67 32

62*** 15

79*** 37

94*** 62

Agree Disagree I am well informed about recycled water use at CH2

Agree Disagree I am satisfied with recycled water use as it will occur at CH2

Agree Disagree Recycled water use at CH2 has been implemented in a fair manner

Agree Disagree I trust the water authority to ensure recycled water safety in the CH2 building

Agree Disagree

37

We need to use recycled water for the future's sake

33

I am confident there are no health risks involved with recycled water use

Agree Disagree

• significant at the 0.01 level, ** significant al the 0.05 leve/, ••• significant at the 0.001 level.

Conclusion The results from chis study of benchmark attitudes of Melbourne C icy Council workers co recycled water use provide information co water retailers and water policy d evelopers. In particular the resu lts indicate respondents are happy with the recycled water use that will occur at the CH 2 office building (toiler flushing, cooling cower system, street cleaning and street tree watering) . The results also indicate support for using recycled water for purposes ocher rhan chose planned fo r the CH2 building but potentially applicable co other office buildings incorporating recycled water use: public fountains and water features, and potentially washing hands and showering. Results indicate chat rhe feas ibility of recycled water use for these p urposes in fu rnre o ffice buildings would be strongly facilitated by enhancing trust, fairness, and provision of information. Somewhat surprisingly, a greater proportion of respondents moving into the CH 2 office building were happy with recycled water use in the cooling system, compared co chose chat won't be working in the 64 NOVEMBER 2006

Water

building. The results of chis study also indicate chat experience of recycled water could facilitate greater acceptance, and suggests co recycled water retailers and policy developers chat providing people with some experien ce or trial of recycled water may help increase acceptance and use. Respondent occupation was an influencing factor on attitude to recycled water use. Results may indicate chat engagement with environmental sustainability issues may increase happiness to use recycled water. Further research into occupational influences on recycled water use acceptance would be valuable. Results indicate chat demograph ics did not play a significant role in individuals' attitudes to recycled water use. Of greater importance, as scared before was their trust in the water authority, perception of fairness in the recycled water system, perception of risk involved with recycled water use, perception of being well informed about recycled water use, perceived need to recycle water, satisfaction with recycled water use, and attitude to the environment. This indicates to water

Journal of the Australian Water Association

retailers and recycled water policy developers that these factors are important in fostering acceptance of recycled water use. Overall the results presented and d iscussed in chis paper provide support for the use of recycled water in the CH2 office building, and suggests char in such a context ocher uses of recycled water could be facilitated with the support of building users. Given chat a cross-section of occupations was surveyed the results may be generalisable to ocher large organisations in Australia. However, further research with ocher organisations would be beneficial. Further long term research with CoM employees in relation co recycled water use in the CH 2 building would be beneficial to monitor change of attitudes over time and further inform the Australian and international policy makers regarding attitudes to recycled water use and thus facilitate ics fu rther feasibility.

Acknowledgments The Author thanks and acknowledges the support provided for chis research from an


Early Career Researcher Grant provided by the Faculry of Architecture Building and Planning, T he Universiry of Melbourne. The author also wishes co thank the following people and organisations for their support of chis research: Professor Kevin O'Connor, Dr Dominique Hes, Ms Lorenne Wilks, Ms lone McKenzie, Mr Adam Leggett, The Ciry of Melbourne, and the participants of chis survey - employees of the Ciry of Melbourne.

The Author Dr Anna Hurlimann is a Lecturer in Urban Planning at the Faculry of Architecture Building and Planning at the Universiry of Melbourne, Victoria 3010. Ph: 03 8344 6976, Fax: 03 8344 5532, Email: anna.hurlimann@unimelb.edu.au References Bruvold, W. H. (1972). Public Attitudes Toward Reuse of Reclaimed Water. California, University of California, Water Resources Centre: 54. Eccleston, R. (2006). Bottom's Up/Aqua Blue. The WeekendAttStralian Magazine. Sydney July 29-30: front cover and p22-27.

Government of South Austral ia (2003). Water Proofing Adelaide, Beyond the Drought. Adelaide, Government of South Aust ralia. Government of Western Australia. (2003, February). "A State Water Strategy, for Western Australia." Retrieved 21 September, 2004, from hrrp://www.ourwaterfuture.com. au/Docs/State_Water_Strategy_complete.pdf Hurlimann, A. (2006). An Exploration of Community Attitudes to Recycled Water Use -An Urban Australian Case Study. PhD Thesis at the School ofCommerce. Adelaide, The University of South Australia. Liken, R. (1967). The Method of Constructing an Attirude Scale. Readings in Attitude Theory and Measurement. M. Fishbein. Sydney, John Wiley and Sons Incorporated: 90-95 . Marks, J. (2004). "Advancing Community Acceptance of Reclaimed Water." Water

journal ofthe Australian Water Association 3 1(5): 46-5 1. Marks, J . S., B. Martin, M. Zadoroznyj (2006) . "Acceptance of Water Recycling In Australia: National Baseline Data." Water journal ofthe Australian Water Association 33(1): 96-10 I . McKay, J. and A. C. Hurlimann (2003). "Attitudes to Reclaimed Water fo r Domestic Use: Part 1 Age." Water, journal ofthe Australian Water Association 30(5): 45-49. Othman, M. and N. Jayasuriya (2006). T echnical Research Paper 7 - Water. CH2 Technical Research Paper Series. T. C. o.

Melbourne. Melbourne, The City of Melbourne: 20. Sims, J. H. and D. D. Daumann (1976). "Professional Bias and Water Reuse." Economic Geography 52(1 ): 1-10. SPSS Inc (1997). Statistical Package for the Social Sciences. Chicago, lL, SPSS. T urnbull, M. (2006). Federal Government comm its fu nding to find long-term solutions to Goulburn's water supply. Australian

Government National Water Commission Media Releases. Canberra, Australian Government. 26 May: viewed October 2006 <http://www.malcolmrurnbull.com.au/news/ article.aspx?lD=444>. Victorian Government Department of Sustainability and Environment (2004) .

Securing Our Water Future Together (Victorian Government White Paper). Melbourne, Department of Sustainability and Environment. Water Futures Toowoomba. (2006, 7 August). "Water Futures Toowomba - Referendum Results Website." Retrieved I September, 2006, from http://v,ww.toowoombawater. com.au/general/waterfuturesvoteddown.html. Yamagata, H. , M. Ogosh i, Y. Suzuki, M. Ozaki, T.Asano, (2002). On-Site Water Recycling Systems in japan. World Water Congress, Melbourne, International Water Association.

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fereed paper

PLANS FOR SEAWATER DESALINATION IN CALIFORNIA N Voutchkov Abstract This paper lists a number of desalination plants proposed for coastal California in the next decade and discusses the advantages and challenges, both economic and environmental, of seawater desalination.

Proposed Seawater Desalination Plants in California

Introduction Australia and California share many common featu res: over 75% of their population lives along the coast; they have semi-arid climate with prolo nged drought patterns which pose challenges co traditional water supply practices; and are in pursuit of sustainable and forwa rdlooking resource management char addresses coday's water supply challenges without jeopardising the ability co meet the needs of future generations. Over the last several years, harvesting fresh water from the Pacific Ocean has been riding a rising ride of interest in California as many coastal municipali ties and utilities are challenged with population growth pressures, dwindling water supplies, and escalating water production costs. By year 2030, the state's population is p rojected to increase from 36.5 co 48 mill ion, which in turn would require approximately 4000 ML/d of new water supplies. In recognitio n chat relying only on traditional water supply sources, conservation and reuse may nor be sustainable in the long term, the California Department of Water Resources (DWR) has charred a new course for exploration of seawater and brackish water desalination as an alternative water supply source for the state. It is expected co yield over two dozen new projects statewide which would supply up co 10% of the coral water demand alo ng the coast by year 2020 and would produce approximately 2000 ML/d of new drinking water by 2030. For comparison, the Metropolitan Water District of Southern California currently supplies 6500 ML/d of water co residents of Southern California and serves population of 18 million. Approximately one-half of chis water (3200 ML/d) is imported fro m Colorado River. The fresh water from the desalination plants is aimed to replace a portion of the imported water, provide relief for the over66 NOVEMBER 2006

Water

Santa Cruz

Moss Landing/Monterey Ba Re ional Pro¡ect

Cambria

.. Huntln ton Beach Dana Point San Onofre Carlsbad

Figure 1. Proposed Seawater Desalination Projects in California.

Desalination may supply I 0% of their total water demand by year 2020. pumped groundwater aquifers and rivers, and potentially accommodate some of the planned population growth pressures along the Pacific coast. Si nce seawater desalination creates a new local source of fresh water, most of the key decisions regarding its most appropriate use are goi ng to be made by the communities char would host the desalination planes. Locations of some of the proposed seawater desalination initiatives through out th e state are depicted on Figure I.

Journal of the Australian Water Association

Seawater Desalination Activities in Southern California C urrently, Southern Cali fo rnia imporcs 50% of its water from two main sources the Sacramento Bay- San Joaquin River D elea and the Colorado River. In order co address the uncertainties associated with the long-term use of imported water from these sources, a number of Sou thern Cal ifornia water util ities have charred plans for a long-term diversification of their water supply portfolios with seawater desalination. C urrently, there are a number of large seawater desalination projects in various stages of develop ment (see Table I) . The first two are well under way, follow ing successful pilot plant trials, and all ochers


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Table 1. Projected Seawater Desalination Projects in Southern California. Desalination Plant/ Developer Huntington Beach/*Poseidon Resources

Capacity ML/d

Intake Type

Target Completion Date

Projected Cost of Water (US$/m3)

200

Co-Located with AES Power Plant

2009

0.70 - 0.75 0.70 - 0.75

Carlsbad/*Poseidon Resources

200

Co-Located with Encino Power Plant

2009

Playa del Rey/ Los Angeles Department of Water and Power

45

Co-Located with Scattergood Power Plont

2015

0.85 - 1.0

El Segundo/West Basin & Central Basin Municipal Water District

76

Co-Located with El Segundo Power Plant

2012

0.80 - 0.90

San Onofre/San Diego County Water Authority & Municipal Water District of Orange County

95

Co-Located with San Onofre Nuclear Power Plant

2015

0.90-l.l

Dana Point/Municipal District of Orange County

100

Slant Beach Wells

2013

0.85 - 0.95

Long Beach/Long Beach Water Department

34

Slant Beach Wells

2012

0.75 - 0.95

* Permits already approved are at the stage of initial feasibility assessment, pilot and demonstratio n scale testing. T he two largest and most advanced seawater desalination projects in Southern California are the 200 ML/d plants planned to be located in the C ity of Carlsbad and Huntington Beach, respectively. Boch projects are co-located with large coastal power planes using seawater for oncethrough cooling. The desalination projects are developed as public-private partnerships between Poseidon Resources and local utilities and municipalities. The environmental impact assessments and local land use permits for the two projects have been completed, reviewed and approved in che first half of 2006. Boch projects have been found viable and environmentally safe and have already received permits to discharge their concentrate to che Pacific Ocean. The permitting process for the cwo projects is projected to be completed by the end of 2006 and project construction is planned to begin in 2007. The projects are

targeted to be in operation by the end of 200 9 and to supply 6 to 10% of che drinking water in Orange County and San Diego Cou nty. The two projects have a number of common drivers: the desire of che utilities in their service areas to reduce their reliance on imported water supplies from Colorado River and the Bay Delea, to drought-proof their water supplies and to gai n more local control over their water resources. Currencly, San Diego County has very limi ted local water resources and relies on Colorado River and Bay Delea water for over 90% of their supplies. T herefore, for example, che City of Carlsbad has decid ed to switch their entire water supply from imported water to desalinated seawater. Most of che other communities that would to be supplied by the Carlsbad seawater desalination plant would supplement between 10% and 30% of their current water supplies with fresh water from the sea.

Figure 2. Proposed site for Moss Landing Regional Seawater Desalination Project. 68 NOVEMBER 2006

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Journal of the Australian Water Association

Orange County has more local water resources and currently imporcs only 45% of their water supplies from Colorado River and che Bay Delea. This county is also a hose to a large groundwater recharge project which would supplement 243 ML/day of che county's water resources. As a result, the desalinated water produced by the Huntington Beach seawater desalination plant wo uld constitute only 6 % of che current county-wide water supplies. The desalinated seawater is planned to be introduced in the Orange Cou nty's regional water supply system where it will be blended with drinking water from other sources. Twelve Orange County utilities and municipalities will have access to che desalinated water. In most cases this source will constitute between 1 and 10% of their water supply.

Seawater Desalination Activities in Northern California The need fo r supplemental drought-relief water supplies, groundwater basin overdrafts and associated seawater intrusion, and the measurable ecological impacts of some of che cu rrent water supply p ractices are che main driving forces for the renewed interest in seawater desalination in Northern Cali forn ia. Mose o f che proposed projects are located in the San Francisco Bay Area and in Monterey County (Table 2). Currencly, a partnership of San Francisco Bay Area water districts (Con era Costa Water District, Ease Bay Municipal Water District (EBMUD), Santa Clara Valley Water District and che San Francisco Municipal Utility D istrict) is studyi ng the feas ibility of several seawater desalination plant locations. If conscruccion of seawater desalination planes is found viable, chis initiative may yield one to three seawater desalination planes wi th a total production capacity of76 ML/d to 303 ML/d within


Table 2. Projected Seawater Desalination Projects in Northern California. Desalination Plant/ Developer Bay Area Regional Desalination Project/ EBMUD, CCWD, SFPUC and SCVWD Low Energy Application of Desalination {LEAD} Project/EBMUD

Capacity ML/ d

Intake Type

Target Completion Year

Projected Cost of Water (US$/ m3)

76 to 303

Unknown May Be Co-Located with Mirant Power Plant

20 11

0.85 - 1.20

5.7

Co-Located with C&H Sugar Plant in Crockett

2010

0.95 - 1.15

Beach Wells

2008

1.10 - 1.30

Sand City Water Supply Project/ City of Sand City San Rafael Bay Water Seawater Desalination Project/ Marin Municipal Water District

38 to 57

New Open Surface Intake

2012

0.80- 0.90

Monterey Bay Regional Seawater Desali nation Project/ Poseidon Resources & Pajaro Sunny Mesa Community Service District

76 to 95

Existing Open Intake or Collocation with Moss Landing Power Plant

2010

0.90 -0.95

45

Collocation with Moss Landing Power Plant

20 10

1.10 -1. 20

10 to 17

Existing Open Surface Intake

2012

0.85 - 1.00

5

Beach Wells

2012

0.90 - 1.10

Cambria Desalination Project/Cambria Community Services District

1.5

Beach Wells

2012

l. l 0 - 1.30

San Luis Obispo Desali nation Plant/C ity of Arroyo Gronde

7,1

Beach Wells

2015

1.00 - 1.20

Moss Landing Seawater Desalination Project/ California America n Water Company City of Santa Cruz & Soquel Creek Water District Marina Coast Water District & Fort Ord

the next 5 years. The San Francisco Bay seawater desalination feasibility study is planned to be completed by the end of

Marin Municipal Water District is also developing a large seawater desalination project in the San Francisco Bay area. This project is targeted to produce between 38

2006.

ML/d and 57 ML/d of desalinated water and to provide reliable, drought-proof alternative to the construction of a new pipeline for supplemental water supply

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Journal of the Australian Water Association

Water

NOVEMBER 2006 69


from the already over-allocated Russian River. Marin Municipal Water District has recently completed a 12-monch desalination pilot rest and is well under way with the p reparation of environmental impact assessment for this project. The draft environ mental impact report is expected to be circulated for public review by the end of 2006. Monterey County, which is located south of the San Francisco Bay Area, is currently the area for the development of several new seawater desalination projects. Two large competing p rojects are proposed in the City of Moss Landing. The first project is a 76-95 ML/d regional seawater desalination facility planned to be delivered under a public-private partnership between PajaroSunny Mesa Community Services District and Poseidon Resources. Its main purpose is to replace the use of groundwater from rhe coastal aquifer with desalinated seawater and thereby to minimise further seawater intrusion. T he regional desalinatio n plant would be located at a former National Refractories industrial plane sire, which is adjacent to the Moss Landing Power Generation Station (F igure 2). This desalination project would use the existing

in some parts of che state is as low as US$0.15/m 3. However, the quantity of such low-cost sources is very limited (less than 30% of the water resources statewide). For example notwithstanding char over 40% of the current Orange County water supplies are in chis category, the county water agencies have embarked on exploring seawater desalinat ion because practically all available fresh aquifers delivering chis lowcost water in che county are capped-in and over-drafted. Mose of the utilities in Southern California currently purchase imported water from the Bay Delea and Colorado River at a race of US$0.45/m3 to US$0.50/m 3 and the cost of these water supplies is very likely to increase by US$0.05/m 3 to US$0. l 0/m3 in the next 5 years due to additional expendicures needed to comply with more stringent drinking water quality regulatory requirements recently p romulgated by the US EPA. Water coses fo r the utilities depends on che rime of year and if che supply is interruptible or nor. Based on the 2006 California Water Charge Survey published in July this year by Black & Veatch (http: //www.bvaeservices.com/ news/ articles /j ul06/ ca_survey_b usinesswire.htm), the

National Refractories open intake and ocean outfall. The California American Company (CalAm) is developing a smaller, 45 ML/d project at rhe same Moss Landing Power Generation Station site and proposes to use the power station's cooling water discharge as an intake and d ischarge of the desalination plant. Besides the several large projects described above, th ere are a number of ocher smaller projects u nder development in Northern California (see Table 2). Most of these projects are in early phases of feas ibility and environmental scudies, and are not expected to yield fu ll-scale desalination planes b efore 2010.

Seawater Desalination Challenges in California Water Production Costs - Currently, the cost of desalinating seawater in California is relatively high compared to char of traditional low-cost water sources (groundwater and river water) and water reclamation and reuse for irrigation and industrial use. Indeed, the cost of traditional local groundwater water supplies

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refereed paper

average residential monthly charge for 1,500 cubic feet of drinking water was US$36.39 (US$0.86/m3). The survey also indicates that the cost of residential water supply has increased by 16 .7% since 2003. Meanwhile, che cost of desalinated water has been decreasing steadi ly over the last 10 years, and as seen in Tables I and 2, the majority of the seawater projects planned to be implemented in the near future, are projected to produce water at a cost of US$0.70/m 3 to US$1.20/m 3. These costs are estimated based on asset life of 30 years and unit power coses of US$0.08/kWh to US$0. l l/kWh. Th is cost is comparable to the fu rn re total costs for delivery of new incremental water supplies co many pares of the state, especially to municipalities and utilities in Southern California. The gen erally lower costs fo r production of reclaimed water and for implementatio n of water conservation measures have often been used as an argu ment against the wider use of seawater desalination . This argument however, is fatally fl awed by the fact chat water conservation and reuse do not create new sources of drinking water - they are merely a ratio nal tool to max imise the

beneficial use of the available water supply resources. Under conditions of prolonged drought when the available water resources cannot be replenished at the rate of their use, aggressive reuse and conservation can h elp bu t may not completely alleviate the need for new water resources and water rationing. An example of this is the period of prolonged drought in California in the early nineties, which sprung the need for emergency fast-track implementation of a number of water desali nation projects in Califo rnia, such as these in Santa Barbara, Moro Bay, Marina Coast, and a few other smaller projects, all based o n the technology of the time. Mainly due to the relatively high water p roduction coses, most of these seawater desalination plants were operated for short periods of time, and after a series of "wet" years follow ing the prolonged d rought spell in the early nineties were operated intermittently. The 19 ML/d Santa Barbara seawater desalination plane ran fo r just a few m onths after start u p an d has been shut down. The Moro Bay desalination facility was operated for approximately 6 months after construction, re-scatted in 2003 and n ow usually operates d uring the high -demand

summer months of the year. The Marina Coast faci lity supplies approximately 10 to 15% of the water district's d rinking water demand. However, recently che plane's beach well intake malfunctioned as a result of beach erosion , and che plant's concencrace injection well lost d ischarge capacity mainly due to scaling. As indicated in Table 2, Marina Coast is planning on abandoning their existing faci lity and building a new bigger seawater desalination plant in the near fu ture. W h ile the relatively high cost of seawater desali nation, and the available low-cost reclamation and reuse measures combined with a period of several wee years fo llowing the long drought spell have marginalised the benefits of seawater desalination in the nineties, the conditions Californi a faces today are very d ifferent. The main d iffe rences stem from the significant reduction of the coses for seawater desalination over the lase I O years, and che incrementally higher costs associated with achieving dramatic increase in water reuse and conservatio n statewide after the initial set of low-cost/high effect water reclamatio n and conservation

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Journal of the Australian Water Association

Water

NOVEMBER 2006 71


environmental benefits. Similarly, seawarer desalination p rovides additional benefits in the rime of drought where traditional water supplies may not be reliable and their scarcity may increase their otherwise relatively low costs.

measures are implemented . While in che early nineties extensive conservation and reuse were uncommon for the majo rity of che municipalities in California, che prolonged drought during chis period forced many utilities co implement low-cost water reuse and conservation measures chat now constitute 5 and 15% of their water portfolios. Utilities which already have comprehensive water reuse and conservation programs will not be able co "squeeze" another 10 co 15% of water savings via the same low-cost reuse and conservat io n measures. Implementing the next tier of more sophisticated equipment and technology-intensive reuse and conservation measu res to reach water-saving goals of 20 co 25% comes at a price which in some cases may near chat of desalination.

Energy Use - Salt separarion from seawater requi res a significant amount of energy co overcome the naturally o ccurring osmotic pressure exerted on the reverse osmosis memb ranes. This in turns makes seawater desalinatio n several times more energy intensive rhan conventional treatment of fresh water resources. As indicated previously, a number of water agencies and municipalities in San D iego County, Los Angeles Coun ty and Orange County in So uthern California however, have co import and convey a portion of their uncreated source water ac an additional energy expenditure of 1.7 to 2.5 kWh/m3. W hen chis energy use for conveyance of source water is added to che energy needed for water treatment, the total power demand for production of fresh water from imported sources to che southern pare of the state is comparable to

Typically, seawater desalination cost benefits extend beyond che production of new water supplies. If seawater desalination is replacing che use of over-pumped coastal or inland groundwater aquifers, or is eliminating further stress on environmentally sensitive estuary and river habitats, than che higher costs of chis water supply alternative would also be offset by its

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water

Journal of the Australian Water Association

that of desalinating seawater locally. W h ile energy use for seawater desalination is projected to decrease further with 10 to 20% in che next 5 years as a result of further tech nological advances, the total energy demand for conventional water treatment would likely increase by 15 to 20% in the same time frame because of the energy demand asso ciated with the additional treatment (such as micro- o r ultra-filtration, ozonation, UV d isinfection, etc.) which would be needed in order co meet the most recent regulatory requirements for production of safe drinking water in the USA. Energy use for seawater d esalination of Pacifi c Ocean water could vary in a wide range mainly due co variation of salinity and temperature o f the source water along the coast. For example, San Francisco Bay water and ocean water influenced by fresh water influx from nearby rivers, sloughs, or marshlands, could be of lower salinity (2.6% to 3.0%) than typical open ocean water, which contains 3.35% of total dissolved solids. Use of lower salinity source water in turn would require less energy to produce the same drinki ng water quality.

Seawater Intakes - As seen on Tables 1 and 2, over half of the seawater desalination projects under consideration are proposed to be co-located with power plants. Colocation yields a number of benefits mainly because it avoids construction and permits for new intake and concentrate discharge facilities, and because of the energy cost savings associated wi ch the desalination of warmer source water. Co-location, however, have been considered undesirable by environmental groups due to the potential loss o f marine organisms caused by their impingement against the screens of che power plant intake and as a result of their entrainment inside the power plant conveyance and cooling system. The actual significance of the loss of marine organisms due to once-through cooling as co mpared to other beneficial uses o f the ocean such as commercial and recreational fishing is a subj ect of debate and a flurry of recent federal and state regulations. By early 2008, the 21 once-through cooling plants along the California coast are required to prepare comprehensive plans for reduction of impingement and entrainment of marine organisms. A range of measures under consideration enco mpasses from small modifications of che existing power plan t intake facilities to reduce through-screen velocity and flow , to major changes such as replacement of power plant seawater oncethough cooling system with air-cooling towers o r with water close-circulation cooling cowers.


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Opponents of co-located seawater desalination plants have often presented the argumen t char if the power plant changes its cooling system in the future, seawater desalination at the particular location would no longer be available. T his argument however, is unfounded in reality, because most co-located desalination facilities have already executed long-term agreements with their power plant hosts to reserve the right to use their outfall and intake sys tems and equipment even if the power plant no longer needs them in rhe future. The main benefit rhe co-located desalination plants would lose in this case is rhe availability of warmer source water, some 5 to 15% of the energy cost, while the cost savi ngs from the use of the existing power plant in rake and outfall facil ities would be over 25%, resulting in a significant net benefit with or without the power plant in operation. Various forms of sub-surface intakes (i.e. beach wells and horizontal directionally drilled (slant) wells) have been heavily promoted by rhe California Coastal Com mission and local environmental groups as a viable alternative to power plant co-location and construction of new open intakes along rhe California coast. Although these environmental advocates have repeatedly made claims char wells would not cause any impingement and entrainment of marine organisms, to dare there are no studies or fu ll -scale data char support these claims with factual scientifically generated information. In addition, nether the US Environmental Protection Agency nor the Cali fornia Seate Water Quality Control Board that have jurisdiction over the enforcement of federal and state and intake-related regulations have recognised intake wells as Best

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Technology Available for effective red uction of impingement and entrainment of aquatic organisms. For comparison, comprehensive one-year studies completed at the co-located intakes of the Huntington Beach and Carlsbad seawater desalination projects have ind icated that these intakes would nor produce additional impingement, and the incremental entrainment attributed to their operation would be less than I%. Su bsurface well intakes are not likely to impinge and entrain large amounts of adult marine organisms. However, they may cause entrainment of marine life inside the sand substrate below the bottom of the ocean floor as the seawater passes through this substrate on the way to enter rhe co llector arms of the intake wells. The natural subsn:ate media (typically sand, gravel and rock) that separates the collector arms from rhe bottom of rhe ocean works as a filter that would retain nor only inert solid particles co n rained in the seawater bu r also small fish larval eggs and other zooand phyto- plankton. Unless there is a natural mechanism, such as adequate tidal wave or wind action or local currents to scour and flush the bottom ocean floor substrate frequently enough to release the entrained organisms, this seawater plankton would be retained and lost in rhe substrate as it would be in the open power plant or desalination plant intake facili ties. The viabili ty of subsurface well intakes for large seawater desali nation plants along the California coast have not been proven to dare. None of the ongoing pilot studies of subsurface intake wells have been able to produce large amounts of seawater and to generate systematic long-term performance data to prove that this type of intake can

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WATER REUSE

• Compact treatment plants • Sewer mining plants • Water reuse systems


planned to be diluted with che cooling water of che power plane to salini ty levels chat typically do not have significant impact on aquatic life (see Figure 3). The magnicude and significance of impact, however, mainly depend on che type of marine organisms inhabiting the area of the discharge and on che hydrodynamic co nditions of the ocean in chis area, such as currents, tide, wind and wave action, which determine che time of exposure of the marine organisms to various salinity conditions. Extensive salinity tolerance scudies co mpieced over che lase several years at the Carlsbad seawater desalination demonstration facil ity indicate chat after concentrate dilution with power plane cooling water down to 4.0% or less, the combined discharge does not exhibit chronic toxicity on sensitive cesc marine species. Recent acute toxicity studies fu rther show chat sensitive marine species can even tolerate salinity of 5.0% or more over a short period of rime (2 days or less).

sustai n continuous and consistent operation of seawater desalination plants of 20 ML/d or higher. T he ongoing pilot studies at Long Beach and Dana Point pilot slant intake well facilities will co ntinue over the next two years and would hopefully generate a more defi nitive answer regarding slant well intake viability fo r large seawater desalination facilities. Concentrate Management - Seawater desalination plants along the California coast would produce concentrate of salinity that is approximately 1.5 to 2 times higher than the salinity of the ambient seawater (i.e. in a range of5.2% to 6.7%). While most marine organisms can adapt to this increase in salini ty, so me marine species such as abalone, sea urchins, sand dollars, sea bass and top smelt, are less tolerant to high salinity concentrations. Therefore, thorough assessment of the environmental impact of the discharge of concentrate and of any ocher byproducts of che seawater treatment process is a critical part of che evaluation of project viability.

Some seawater desalination projects are planning to use deep injection wells to discharge the high-salinity seawater concentrate generated duri ng the reverse

At seawater desalination projects chat are proposed to be co-located with power planes, che desalination plane discharge is

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Journal of the Australian Water Association

osmosis separation process. The fu ll-scale experience with chis concentrate disposal method in California to date is very limited. Currently, several pilot studies are underway along the California coast to cesc alternative deep injection well technologies fo r concentrate disposal. The results of these smdies would yield additional information regarding the viability of this co ncentrate disposal alternative. A third disposal alternative, besides inj ection wells and co-disposal with power plant cooling water, currencly under consideration for implementation at several seawater desalination projects in California, is the discharge of the concentrate through existing wastewater treatment plant ocean outfall. T his type of disposal has been practiced briefly at the Santa Barbara seawater desalination plane during its shorelived operations. Discharge resting during che period of plant operations has revealed a potential concern associated with the ionimbalance toxicity of the mix of desalination plant concentrate and wastewater effluent.

Concluding Remarks Within the next five years many Californian coastal communities are planning to make seawater desalination a permanent part of their water portfolio. O ver cwo dozen seawater desalination planes supplying up to 10% of California's total water demand are projected are planned to be build by year 2020. In che next five years, the mai n developments in che desalination arena are anticipated to occur in Southern California, where currently several large seawater desalination projects are in advanced stages of development. Many of che ongoing feasibil ity studies in Northern Californ ia are also likely to yield at least two to three full-scale seawater desalination proj ects by 2015. Although existing fresh water sources, co nservation and reuse would continue to play a central role in the state's long-term water supply strategy, seawater desalination has a strong appeal to many coastal communities because it is a reliable and sustainable drought-proof source of drinking water char can be developed and controlled locally.

The Author

Nikolay Voutchkov is Senior Vice Presidem - Technical Services, Poseidon Resources Corporation. He was an invited key-note speaker at the AWA Specialist Conference on Membrane T echnology, 2005 (reported in Watn; May, 2005), email: nvoucchkov@poseidon l .com


Joe White Maltings Membrane Bioreactor (MBR) - Reverse Osmosis (RO) Plant, Perth, Western Australia.

Abstract This paper summarises the successful postco mmissioning performance of an industrial water recycl ing installation, incl uding comments on overcoming early bio-fouling experiences.

Introduction During late 2005/early 2006, Tenix Alliance designed, co nstructed and commissioned Australia's largest industrial Membrane Bioreactor (MBR)/Reverse Osmos is (RO) water reuse system for the Joe White Maltings QWM) facility in Perth, Western Australia. The operational design is for treatment of an average 1.41 ML/day of malti ngs plant wastewater equating to a dai ly load of2,240 kg BO D/day. The design consists of a continuously fed and aerated bioreactor with recycle through a membrane

bioreactor co mpartment consisting of eight Koch PuronÂŽ Hollow-Fibre Ultra-filtration (HFUF) membran e modules. Membrane fil tration is followed by Reverse Osmosis treatment where 75- 80% recovery is achieved.

Converting 3000 mg/L COD into near-potable water. The combi nation of Membrane Bioreactor (M BR) and Reverse Osmos is (RO) technology was adopted for che new wastewater treatm ent plane to provide a treated water stream of a quality equal ro, or better than, Australian Drin king Water Guidelines. The plant was commissio ned in March 2006 and its design was discussed in a previous technical paper featu red in that

Table 1. Influent W astewater C haracteristics - Des ign and Actual. Parameter

Flow (kl/L) BOD (mg/L) COD (mg/L) TSS (mg/ L) TN (mg/L) TP (mg/L)

Design 50%ile

1410 1600 3000 327 70 8

PH *Values represent ranges not percentile.

Design 90%ile

Actual 50%ile

Actual 90%ile

1700

1264 1600 2900 148 44 14 *4.8-6.0

1331 2160 3886

2000 3850 500 100 10

382 58.2 22.4

month's iss ue of Water ('Australia's cwo largest MBR Water Recycling Planes', M. Newland, pp 59-62). Th is fo llow-up paper derails some of che technical experiences during the six months of the commission ing and proving periods and demonstrates the reuse water quali ty that can be ach ieved with a rightly integrated MBR-RO approach.

Joe White Maltings Facility, Perth Joe White Malti ngs Pry Lrd recently ex panded the production capacity at their Penh malting facility by over 120%. A key component of this expansion project was the provision of an integrated wastewater treatment an d water recycling facility on sire ro replace an ex isting under-capacity, poorly performing system. T he mal ting process involves the germination of barley, where starches are converted ro maltose. Ultimately the malt is shipped ro breweries both nationally and internationally. T he malting operation is a 24 hour per day, 365 day per year batching operation and is one that produces a relatively high volume of wastewater as the germination process is initiated by steeping the barley in cop ious amounts of water for approximately 21 hours and then draining off the resultant liquor.

The Treatment Process The wastewater treatment process consists of screening, flow equalisation , aerated

Journal of the Australian Water Association

Water

NOVEMBER 2006 75


bioreactor, membrane b ioreactor filtration (two parallel membrane tanks) , reverse osmosis and mechanical biosolids dewarering. PuronÂŽ MBR membrane modules, manufactured by Koch Membrane Systems in Germany, were selected fo r this project. These membranes consist of reinforced hollow fibres with single end attachmen t. The Reverse Osmosis plan t was also p rovided by Koch Memb rane Systems an d incorporates fiftee n " 18 inch" d iameter by 1.55m MegaMagnumÂŽ, Ultra Low Pressure, spiral wound RO elements. These membrane technologies have been successfully integrated by Tenix Alliance designers into a compact and robust biological treatment process. The malcings wastewater BOD concentration is significancly higher than domestic sewage and hence chis project, to the best of our knowledge, still represents che largest M BR in Australia when measured on the basis of d aily organic loading rate.

Joe White Maltings MBR WWTP Bioreactor a nd Membrane Tanks. Table 2. Membrane bioreactor (MBR) permeate quality criteria.

Plant Performance

Parameter

Key aspects of che plan e performance over the period since Ju ne 20 06 when the exp anded malcings facility reached fu ll capacity are summarised below.

BOD (mg/L) COD (mg/L) TSS (mg/L) TN (mg/L)l TP (mg/L) PH TDS

Influent wastewater characteristics

T he in fluent wastewater characteristics have been moscly consistent with key design criteria (Tab le 1) and it is expected that all wi ll fall within range with a h igher sample population. Membrane bioreactor performance

The mem brane bio reaccor permeate quali ty has met che expected stan dard. Som e biofouli ng was observed with in the permeate manifo lds and permeate balance tan k approximately three months aft er start-u p. Measurements of slight concentrations o f suspended solids in some samples reflected slo ughing off of

Design 50%ile

Design 90%ile

Actual 50%ile

Actual 90%ile

<5 120 <1 5

10 150

<5 174 3.4 7 0.38

1600

2000

<5 155 <1 4 0.2 *7.8 - 8.1 1575

5 7 2

1830

*Values represent ranges not percentile.

small amounts of chis b iofilm growth and significan cly increased p ressure drop was also noted across the Reverse Osmosis system pre-fi lter cartridges at chis ti me. Inspection confi rmed some biofou li ng of che woven polyp ropylene fi lters. There was also evidence of min or biofilm growth in the pressure vessels and manifolds at the fron t end of the

RO system. The pre-filter cartridges were replaced and a routine, but more concentrated, chemical clean of both the M BR membrane syste m and th e Reverse Osmosis system was carried o u t. A chloramine dosin g system has now been install ed on che p lane and has very su ccessfully prevented any fu rther biofouli ng.

Table 3. Reverse-Osmosis (RO) Permeate Q ual ity.

Parameter

Design

Actual 50%ile

400 15

200 3

75% of samples free

<1 (100%)

75% of samples free

<1 (100%) 1 <0. 1

,f 1

TDS (mg/L) Colour 2Total Coliform Units (cfu/l 00ml ) 2Thermotolerant Coliform Units (cfu/ 100ml) Total Nitrogen (mg/L) Total Phosphorus (mg/L) Recovery 1True

~0 W A T ER

Treated water from the MBR and RO treatment steps.

76 NOVEMBER 2006

Water

1. Sample population = 12 samples 2. Based on 6 Pathology samples

Journal of the Australian Water Association

75 - 80%


T he MBR permeate does contain some residual, soluble, non-biodegradable COD. T his imparts a light tea colour to rhe water, although rhe colour is quire effectively removed in rhe subsequent RO seep. Reverse osmosis performance

The Reverse Osmosis permeate has also been of a high quality and consisrenr wirh rhe anricipared performance criteria (Table 3) . T he recovery of pe rmeate water has readily mer rhe required carger of 75% with rhe inflow flow typically being 1,250 - 1,350 kL/day. T he plane is now being optimised co increase recovery co 80%. fr shou ld be noted char the requ irement was co produce water wirh less than 400 mg/L T DS, although the design intent was co achieve less rhan 250 mg/L TDS. Consequently the Koch Ultra Low Pressure (ULP) RO membrane was specifica lly chosen for chis app licat ion, with t he advantage of being able co operate at lower pressure (lower powe r consu mption) compared co ocher higher rejecti on/highe r press ure membranes withi n the Koch RO membrane range chat can produce higher quality water if requ ired. Full analytical resting has been carried our on several samp les of the reverse os mosis permeate water an d rhe res ul ts have reported well with in all Australia n Dri nk ing Water Qual ity Guideli ne parameters (data nor shown). T he RO concentrate scream, with a TDS conce ntration of approximately 6,800 mg/L, is directed to the sewer. The BOD concentration of chis screa m is typically < 10 mg/L.

Operational PuronÂŽ MBR membrane filtration modules.

Summary

The Authors

This MBR - RO facility is a demonstration of how membrane technologies can be successfully integrated with biological reactor design to achieve a significant water saving outcome. Moreover, it is equally significan t for water providers, ind ustry and rhe community char these technologies are now enabling such projects co be economically justified when compared to rhe srarus quo of simply using potable wate r and discharging trade waste co sewer. T he approach is also applicable co sewer mining applications in order co recover high quality water fo r re-use. Joe White Malcings in Perch now benefits rhe com munity by conserving some 400 ML of potable water each year.

Mark Newland is Principal Process Design Engineer with Tenix Alliance Pry Led and has over 18 years practical biological wasrewarer rrearmenr plane design and commissioning experience. He leads rhe process engineering, technical innovation and commissioning team with in Tenix. Conracr: Phone (08) 9270 1500, mark.newland@cenix.com; Brent Gibbs is a Process Engineer with Ten ix All iance Pcy Ltd. Brent has a doctorate in Biotechnology and Engineering from Murdoch University, Western Australia and has commissioned both che Victor Harbor and Joe White Mal rings MBR wastewater rrearmenr planes completed by Tenix. Contact: brenc.gibbs@cenix.com

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Water

NOVEMBER 2006 77


technical features

SMART SEWERS - RIGS, A GOLD COAST INNOVATION B Douglas Abstract This paper sum marises the development, design and construction of gravity PVC Smart sewers that are used to achieve Water Sensitive Urban Design (WSUD) goals. T he paper details specific design aspects of the development of PVC Smart Sewers for the Pimpama Coomera Waterfuture Masterplan within the Gold Coast area of South East Queensland, the design feat ures of the PVC smart sewers constructed at Pimpama Coomera and the flow monitoring carried out on installed PVC smart sewers.

Introduction Since the start of this century, South East Queensland (SEQ) has been in a d rough t. With chis d rought has come an u nderstanding fo r Gold Coast City Council (GCCC) through Gold Coast Water (GCW) chat a completely fresh approach was needed fo r water resource management in the water cycle. This has meant that ind ivid ual aspects of the water cycle could no longer be viewed in isolation and a bri n ging together of these components was achievable through the use of an integrated urban water management master planning process for the region . GCCC commenced chis master p lanni ng process in early 2002 for the Pirnpama Coomera region as it was identified as our next large G reen field development area with in the city's town plan. T his region is projected to grow from 5,000 equivalent tenements (ET) to 50,000 ET over the next 50 years, (for GCW lET = 825L/ET/d fo r ADWF). A discussion paper was developed in November 2002 to provide a fu ture framewo rk for the development of the Pimpama-Coomera Integrated U rban Water Master Plan. This document states at page 1, "Communities all over the world are challe nging the way water and wastewater services are provided to existing and new urban commu nities. Gold Coast Water recognises ch is an d is looking at a more integrated approach to meet the needs of the p rojected growth in population and at rhe same time protect the environmental values of rhe area."

78

NOVEMBER 2006

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Ar th is time GCW management was bringing together a focused team of internal and external person nel to develop the Pimpama Coo mera Masterplan based on WSUD principals. For sewerage infrastructure, the discussion paper clearly defined the lack o f uptake by GCW of improvements in the materials used in sewer construction, the methods of sewer construction, equipment used in sewerage maintenance and sewerage management systems. Also, the existing design criteria of SxAD WF for sewers included an allowance fo r stormwater infiltration and inflow of about 40%. Cou ncil was very aware of excessive system flows from I nflow as some existing catchments had been recorded with flows of well over l Ox ADWF. T here are significant opportunities to reduce the allowance fo r Infl ow and Infiltration of stormwater and gro undwater by using more flex ible, warerrigh r p ipe materials, smaller watertigh t access structures, red uced numbers of access structu res and righter asset creatio n controls. Essentially ch is is a smarter way of servicing urban communities, thus the term 'smart sewers'. W ith the speed of development wo rks occurring in the Pimpama-Coomera area in early 2003, the d ecision was made to apply to all new development applications in the Pimpama-Coomera region an additio nal condition fo r the provision of smart sewers and dual ret iculatio n

Reducing inflow and infiltration by using more flexible, watertight pipe materials. Th is single decision imposed a significant rime co nstraint as the required infrastructure would have ro be designed and co nstructed over the following 4 to I 2 month period. To meet this need requ ired a complete set of design guidelines, standard specifi cations an d standard d rawings so that consu ltants cou ld design the system and contractors could build the systems and council knew what it was

Journal af the Australian Water Association

getting. T hese documents were required to integrate with and complemen t GCCC's existing set of guidelines, standards and specifi cations.

System Development Sewers based on gravity designs have been developed over thousan ds of years, removing waste prod uct from areas of high human hab itation to areas downstream where there is liccle h uman hab itation. M odern sewerage systems developed w ithin the last century replicated these basic design functions bur upgraded them with the appl ication of mod ern materials chat were availab le at the time e.g. brick manh oles were replaced w ith co ncrete manho les and clay pipe replaced with PVC p ipe. It sh ould be noted that the contin ued use of un-plasricised poly vinyl ch loride (PVC) p ipe was strongly q uestioned as poly ethylene (PE) pipe is perceived to be a better product. PE pipe offers some very good b enefi cs as a pure material altho ugh for a sewerage system it presen ts difficulties in installation and particularly in fabricatio n of junction components. Also its assembly in Queensland 's warmer climate could cause some co ntractors difficu lties because of thermal expansion capabili ty of PE and t he impacts that the cu rrent skills shortage in experien ced th ermal welders could have on contracto rs were also considered. PVC is a very good material fo r sewerage systems, we just d id not fu lly understand the material and how it was being used and in some instances misused. What GCW wanted fo r a smart sewerage system was one that: • reduced inflow and in filtration over the life of the infrastructure; • addressed specific fai lu re poin ts such as junction co n nections, manhole joints and within the allo tment issues such as the Overflow Relief G u lly (ORG); • was an off-the-shelf system chat was easily assem bled and almost 'Lego' like; • could be d esigned by d ifferent consul tants and assembled by d ifferent co ntractors with repeatable qual ity; and • was developed so t hat ma n u fa cturers cou ld adapt ro the system changes


an d be assisted in developing and provid ing new components. Ac the very start of rhe proj ect discussions were held with GCW maintenance supervisors co identify areas where maintenance activities and inAow and infilrracion occurred. le was clearly identified chat for GCW 90% of maintenance activities were focused on house connection branch junctions, house co nnection branch fitti ngs, house drain connection points co the house connection branch and construction joints in traditional cast in situ manholes and che manhole base joints in pre-case manholes. These discussions focused on both the failure outcome and che cause of rhe fail ure and how in the GCW context these failures occurred and continued co occur. For example, rhe only approved deep sewer junction fitt ings were an out-of- manufacture (by 13 years) iron fit ting, or a coscly and time-consuming-co-source fibreglass alternative. Due co a lack of adequate communication, some contractors were providing an assembled PVC firring format rhac has generally resulted in a collapsed sewer junction at depths of up co 5.0m. This occurred as it was perceived from our poorly prese nted standard drawing information chat chey could use a PVC firr ing assembly char may or may nor be rein forced by concrete encase ment. To specifically address the deep junction issue ir was decided co provide a new format of junction char was to be factory assembled from available PVC fittin gs. This assembly was to be co mpletely encased in fibreglass wich the addition of a bracing gusset. When the first sample was reseed for fu nction it survived intact when 27kN was applied to the slip pipe. T he slip pipe was pushed 300mm through rhe firr ing so chat the bottom of the slip pipe was presented in che sewer line. One manufaccurer was keen co progress council's idea bu t a better result was developed where all manufaccurers co uld produce the sta ndard counci l item as shown in Figure 1.

Water Supply

Filtration

Irrigation

Drainage

+-'

Q.

E 0 l-.

a.. o?j

>.

+-'

cu :)

0

I a, C.

·-CL ...... ~

<( I

Figure 1. Type D junction fitti ng. The concept of the reinforced sewer firring was then applied co the ocher house con nection branch fitt ings such as 'Y' junctions and bends chat suffer similar failure modes co che deep junctions. An exa mple of a reinforced junction is shown in Figure 2.

a,

..c:

......

..... I

0 I a,

...... (U ......

en

PPI Corporation Pty Ltd

Figure 2. Type A reinforced junction fi tting. le was also evident through these discussions chat manufactured sewer bends we re beneficial to smart sewerage systems as these bends were just a piece of pipe and pipe is the lease of our troubles.

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Journal of the Australian Water Association

I Export Enquiries: Ph: +61 7 3865 3699 Web: www.ppi.com.au Email: sales@ppi.com.au

Water

NOVEMBER 2006 79


A local Brisbane manufacturer, A & L Industries, was at chis time developing 3.0m radius 150mm sewer bends chat can be used as a rep lacement for an access structure where no influent main intersects the structure. Figure 3 shows a bend chat has replaced an access structure.

there was one existing man ufacturer and two manufacturers wanting to get their maintenance shafts into use. O ne type of Maintenance Shafe is shown in Figure 5.

were co provide an overfl ow to stormwacer as a part of the pools installation thereby negating the residents need to dump stormwacer into the sewerage system. This was brought about by p roviding sub missions to the State Government chat resulted in all pools being required to provide a stormwacer overflow via Local Governm ent Association of Queensland C ircular n umber 2005-196 regarding swimming pool discharge.

Relations with the Consultants and Manufacturers Figure 5 . Selectio n of Poo PitÂŽ maintenance shafts.

Figure 3. 150mm sewer bend.

The RIGS System Takes Shape

With manholes it was evident chat the sitecreated joints were the main areas where inflow and in filtration occurred and this was generally followed by root intrusion and a maintenance intervention. It was accepted that the use o f factorymanu factured m anhole bases was the most appropriate way co fix these issues fo r precast units.

During chis develop ment period it was identified that the use of the term 'smart sewer' covered a wide range of system types and a definitive name for the system was needed. It was decided chat the name of che system sho uld refl ect the basic intent, so the name Reduced I nfi ltration Gravity Sewerage system, or RIGS system, was born with a selection of existing and modern components developed for its intended use.

With the selection o f approved p re-cast manhole bases came the availability of factory finished benchi ng that p rovided a controlled quality of fi n ished product that m ini m ised the contractors' construction time. A pre-cast man hole base with fac tory provided benching is shown in Figure 4 .

Figure 4. Pre-Ca st MH base w ith factory benching. For cast in situ ma nholes it was determined chat che best way co address these sitecreated joint fa ilures was to use water scops, hydrophilic seals and full steel restraint at che various constructed join cs in the cast in situ ma nhole. T o further enhance the modernisation of the sewerage system, the use of maintenance shafts was considered as a significant alternative for all types of concrete manholes. GCW was prepared to allow che replacement o f five manholes with five maintenance shafts with a standard manhole to be provided at either end . GCW was fortunate ac that time as 80 NOVEMBER 2006

Water

A significant lesson from the RIGS developm ent process was the relationship between what was occurring within the allotment and what was occurring outside the allotment. Council had for many years d irected chat swimming pools with a backwashing filter were required to connect their backwash outlet to the Overflow Relief G ully (ORG). With chis type of pool installation there is a diversion valve requ ired chat allows the resident to select either O RG for disposal of fi lter backwash or the Stormwater system fo r disposal of rainfall. This format of inscallacio n has led to most residents, during a rainfall event, du mping rainfall captured by the pool into the sewerage system via che O RG. This was made clearly evident to GCW when a local vacuum sewerage pipe work system, that utilises welded PE pipes, was flooded by a 150mm rain fa ll event. The area was surveyed and it was fou nd that 40% of the p roperties were using the ORG as a pavement/yard drainage point and 80% of the properties were using che O RG as a pool overflow. To address chis internal drainage issue a new format of O RG installation was developed and is being implemented in Pimpama-Coo mera. Additionally the Q ueensland Government was pursued to amend the state's regulatio ns so chat all swimming pools, not just cartridge fil ter swim mi ng poo l systems,

Journal of the Australian Water Association

To p rovide an off-the-shelf, easily assembled system chat can be designed and assembled by different consultants and contractors, it was fortunate th at there were a significant number of manufacturers, who had developed, were developing or were prepared to develop new sewerage system components. Wherever possible components were selected that required no on-site adjustment or adaptation as the cost of the system was a focus point in its selection and design. As an example th e Wormall Poo Pi tÂŽ is a rotamoulded maintenance shaft ch at if moulded in the morning could b e delivered co site that afternoon already set up to provide for the sewers horizontal and vertical alignment. The same general installation outcome is available for the new pre-cast manhole bases that may take slightly longer in their delivery times to the site, as the benching mortar needs to cure before delivery. To ensu re that suppliers and contractors were aware of the changes that the development cond itions p rovided, council undertook a range of industry communications that involved the local contractors' federat ion and prod uce manufacturers and d istributors. With in council's area of control there can 10 to 20 engineering consultancies working on different developments for different owners and as well there can be 10 to 20 d iffe rent construction contractors building the specific infrastructure. This p rovided a very clear need fo r do cumen ts that fitted into the existing development p rocess and clearly defined what GCW expected of a smart sewerage scheme. For the larger engineeri ng consultancies, we provided face-co-face communication and trai ning sessions with a specific Power Point presentation developed fo r this purpose. For smaller consultancies a telephone discussion and em ail provision of the training presentation was carried o ut. These communication sessions were focused on the full range of infrastructure


technical features

that was included in the PCWF Master Plan such as dual reticulation, RIG S, WSUD stormwater and roads. O ther areas where communication and training occurred were for the plumb ing industry as they are end users of the new systems. This training is being continued with the GreenPlumbers initiative. As well, GCW provided a very experienced infrastructure auditor for the PCWF area whose main roles were to comm unicate the RIGS ch anges, provide feedback on the guidel ines and standards and communicate lessons obtained from each successive develop ment on to the next job site that a contractor was commencing. This proved invaluable as the original RIGS guidelines and stan dards were issued in April 20 03 and were upgraded in September 2003 with the cur rent set of documents released in mid 2005 with these documents having d raft amendments awaiting incl usion and publish ing at the next edition .

In develop ing a system that manufaccurers could adapt to, there was an allowance that rhe initial developments providi ng RIGS systems would have some level of difficul ty and shortfa ll in meeting the needs of RIGS due to the speed of its application. Th is was done on a case-by-case basis but each rime chis occurred there was an effort put into defining for the suppliers and manufacturers what was needed on the next job.

System Validation - Getting Smarter/Finding Those Hidden Opportunities As a standard pare of the asset handover process for GCCC, the develop ment consultant is required to certify that the sewerage system is integrally sound through the application of p ressure rest ing to all sewer mains and access structures. This process is applicable ro council's traditional sewerage systems and to RIGS systems. A critical component of the PCWF Master Plan was the validation of the RIGS systems ability to reduce peak wet weather flow from 5 x ADWF to 3 x ADWF . To commence this process two developments were chosen that were closed catchments and thus provided the ability to validate system performance at three stages: o nmain tenance (new), as the develop ment was being bui lt upon and then after the develop ment had been fully built o ut. These estates are the C rystal Creek and Coomera Vista developments and were p rovided with the above nominated testing certifi cation.

The System at New Due to a range of circumstances the C rystal Creek developments flow monitor was installed in July 2004 some six months after the estate was p laced on-maintenance with the installation of the monitoring system occurring during the building period for some of the allotments. The second estate, Coomera Vista, was provided with a flow monitor in early December 2004. The initial data supported the systems pressure testing certification as it showed that no inflow or infiltration was occurring to the sewers. The data showed char over three days d irectly following the calibration of the fl ow monitor, December 9th to 11th 2004, a total of 127mm of rain fell in the catch ment with no inflow or infiltration occurring. Over the next three to fo ur mo nths, the data showed that there were five rainfall events of significance bu t again there was no in flow or infiltration occurring. Followi ng chis initial period of no in fl ow or infiltratio n, as can be seen by the graph in Figure 6 , there was a minor rainfall event on 28th April 2005 where 28 mm of rain fell and 1,600 litres of inflow occurred that

For con crete manhole manufaccurers, there was a dramatic cha nge in produce volume used. For one development there was a reduction in manhole numbers of 80% th rough the use of maintenance shafts and in-line bends. W hile co ncrete struccures were viewed as problematic in some areas there was clear vision of their need in roadway installations due to the potential delicate nacu re of most maintenance shafts during the road construction process and as well there is a general need fo r manholes as a part of the system to allow for larger maintenance activities. There was a clear opporcuni ty for concrete products to be assisted in entering the new world of RIGS that is clearly shown by Humes new Superbowl and Quicktee, (refer ro WSM Product Ap praisals PA 05/15 and PA 05/ 16). The Superbowl and the Q u icktee are factory cast bases that have as a part of the design a finished benching outcome d irect from the casting mould. All the manufaccurer has to do is core the upstream and downstream in lets to the supplied design and deliver the base to site.

For over 80 years we have provided critical water infrastructure and mangement solutions for our clients and communities. Our dedicated team of professionals has specialist skills in engineering, environmenta l, risk, innovation and water cycle management, and can provide integrated solutions for your business. To find out more please contact Selwyn Mcfaul or George Khouri in Brisbane on (07) 3244 9644 or Chris Morris in Sydney on (02) 8923 1555.

Success ,,_,, Partnership, Success ,,_,, People

Journal of the Australian Water Association

JWP Water

NOVEMBER 2006 81


was almost d irectly proportional to the rainfall inten sity. It is to be noted that b uilding works commenced at this site in the third month after the flow monitors installation.

The System During the House Building Period The fi rst decent storm occurred on the 7th of November 2004 providing 140mm over 24 hours. As can be seen by the data on the Graph in Figure 7 there was 4 x ADWF in the system on that day that shows direct inflow occurring with infiltration occurring over the next three (3) days. There were subsequen t storm events that only reiterated the reality that the systems were su ffering inflow and infiltration, refer to the graph in Figure 8.

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The data was collated in July 2005 and p resented to GCW. It was recommended to continue with the monitoring and as well carry out a fu ll p roperty survey together ~ith internal drainage system assessment Regarding maintenance, over the next year there were eigh t specific sewerage blockages within RIGS systems that were generally characterised as 1.5 to 2.0 cubic meters of gravel and soil that had no definable upstream fa ilure point where this ingress could have occurred. I n most of these instances it was identified that there were allotments with recen tly cast concrete slabs. This reiterated co ncerns that d uring the perio d where plumb ing, drainage and slabs are being constructed, there were occasions where the sewer cou ld act as an allotment drainage point causing the ingress of material and the blockage downstream. Feedback from council's maintenance personnel has been integral in th e p rogression of the RIGS system with numerous guideline and specific prod uct improvements identified. Some have been as simple and quick as a rubber Bung while others have been slower due to the time needed to effect change to th e manufactured format of the product, wh ich in some instances takes years to effect.

Conclusions The concept of smart sewers is not abo ut a particular 'smart' piece of prod uct o r material but really about understanding

82 NOVEMBER 2006

water

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Figure 6. Coomera Vista May 2005 Daily Flow Totals Building Works Commenced. 160 140 120 100 80 60 40

90,000.00 80,000.00

T he consistency of the data and the occurrence of the inflow and infiltration following the commencement of the b uilding activity gave a clear indication of its cause. A series of site inspections identified some poor construction/building p ractices but did not reveal any specific si ngle failures such as damaged manholes or maintenance shafts nor any missing covers.

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Figure 8. Crystal Creek 29/30 June 2005 . how your sewerage system is interacting in yo ur world . The RIGS system has been shown to be qu icker to construct, simpler to assemble and proven to be sealed at new. The RIGS system has allowed GCW to better understand the causes of the initial and cu rrently ongoing inflow and infi ltration. T he opportunity fo r council to confiden tly provide sewerage systems that can be designed and built and operated at 3 x ADWF is approaching.

Journal of the Australian Water Association

The Author Bruce Douglas is the Techn ical Supervisor Civil for the Asset Creation Section of Gold Coast Water, a business unit of Gold Coast City Council (bdouglas@goldcoastwater.com.au) .

References Council's design and construction documents are currently available as the 2005 Edition at http://www.goldcoastcity. com.au/t_srandard.aspx?pid=3760


A SUSTAINABILITY FRAMEWORK FOR THE AUSTRALIAN WATER INDUSTRY S Lundie, G Peters, N Ashbolt, E Lai, D Livingston Keywords: sustainability, life cycle assessment, risk analysis, mulricrireria assessment, stakeholder participation

Abstract In chis article we discuss rhe application of strategic planning cools in the Australian water industry and a framework for assessing the sustainability of new investments in water cycle management. Created in a research project partly funded by the Water Services Association of Australia, the Sustainability Framework is based on raking rhe best of current strategic planning and sustainabili ty assessment approaches, including appropriate levels of interaction with public and government stakeholders. It embraces recent developments in the application of life cycle assessment and ocher information cools. The intent is to deliver a guide which provides for both analytical and participatory aspects of sustainability assessment.

Sustainability Tools in the Australian Water Industry While the idea of strategic planning is nor new, rhe integration of sustainabi li ty assessment cools in a stakeholder-connected planning process is nor universal. The principal relevant cools are described in Box 1. Here we summarise rhe scare of application of some of these cools. Life cycle assessment and life cycle costing

Environmental li fe cycle assessment (LCA) has expanded considerably in Australia since 1999 when Sydney Water performed its first ISO-compliant LCA (Peters and Lundie, 2002) on biosolids management options. Subsequently there has been work on disinfection techniques, sludge digestion alternatives (Beavis and Lundie, 2003), water sustainable urban design (WSUD) concepts (Dean et al., 2003) and a worldfirst, megalopoliran water cycle LCA (Lundie et al., 2004). Combined with a simple life cycle costing, ir exami ned a number of future scenarios, fro m variations

in future population statistics, co desalination and WSUD concepts. These studies consistently show char despite additional infrastructure, decentralised WSUD concepts can be quantitatively better for rhe environment. Yarra Valley Water was quick to adopt LCA as an environmental information cool, and published an LCA and LCC study of the sustainability of rainwater tanks (Hall man et al., 2003). The study interestingly demonstrated the significa nce of material and energy demands associated with using rai nwater ranks, though rhe normalisation suggested the benefits outweighed the burdens. Yarra Valley Water has also publ ished srndies on WSUD (Grant et al., 2006) and the relationship between pressure and gravity sewerage (Narangala and Tro tter, 2006). The South Australian Water Corporation has also been an LCA pioneer, performing its first LCA in 2002 - a retrospective comparison of trea tment alternatives ar the Bolivar STP. Subsequent work has exami ned water supply alternatives (including desali nation) for the Eyre Peninsula (Peters and Rouse, 2005) and al ternative reticulation options in its Adelaide water supply (Peters et al, 2006).

A guide for both analytical and participatory aspects of sustainability assessment. Ecological footprint

As ir did with LCA, Sydney Water led rhe Australian water industry into ecological footprint (EF) calculation using a relatively new approach of inpur-ourpur (financial) analysis combined with land disturbance (Syd ney Water, 2001) . Melbourne Water, C ity West Water and South East Water have all subsequen tly calculated an EF. EF has tended to be a cool for organisational rather than options analysis. In an ongoing ARC-funded project rhe Centre for Water

and Waste Technology at rhe University of New South Wales, the School of Physics at Sydney University and Water Service Association Australia are addressing the methodological limitations of rhe existi ng national EF concept by using regionalised input-ourpur analysis and multimedia fate modell ing. Chemical and microbial risk assessment

These tech niques have been in use for some ri me fo r assessing discharges co rhe environment from an ecological and human health perspective (e.g. AWT, I 996). They are gaining more prominence as options assessment cools as the water industry moves in to recycling and needs co reassure people like residential users of recycled water and ocher persons potentially exposed to it (e.g. WSAA, 2004) . Another example was the West Australian EPA's examination of aquifer recharge with recycled water using microbial risk assessment (EPA, 2005). Quantitative microbial risk assessment has progressed to the stage whe re it is has also become the basis fo r setting pathogen levels and treatment performance targets in Australian, US-EPA and other international water quality guidelines (NRMMC & EPHC, 2005; Regli et al., 1999; WHO, 2004).

MCA Mulricrireria assessment (MCA) and multicriteria decision aiding (MCDA) are both integrative cools for the other cools and a potential means for stakeholder engagement. T hey are in widespread use, from si mple applications in assessment of multip le bids fo r contract work, co complex iterative use in developing sustainable planning. Examples of the latter include the community consultation and engagement process fo r the new urban area of Pimpama Coomera and the Gold Coast Warerfutu re projects. Brisbane's Rochedale development area plann ing process employed MCA to compare the options fo r the inregrared water management of this development. Sourh East Water has developed a sustainability assessment cool that incorporates some of the principles of

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NOVEMBER 2006 83


technical features

multicriteria and TBL Define context specific analyses. Sustainability Phase 1 objectives, incl. pri nciples were developed Definition objectives human & environ. needs and criteria were selected fo r J [ achieving these principles for Creative options generation Phase 2 a particular project. In South for water supply and Generation of options Australia, an innovative wastewater services model called the J [ Sustainability Space Model Phase3 was developed. It improved Selection of criteria (1 ° & 2°} Selecting sustainability an existing model that only criteria contained economic, social J [ and environmental Reduce number of options components, by adding time, Phase4 by constraints-driven screening Screening of options political and technological in agreement with stakeholders dimensions. In Western .J L Australia, the Water Phase 5 Generation of Corporation has devised a Perform detailed performance matrix sustainability assessment options assessment process which incorporates .J L Identify preferred option by the three basic sustainability Phase 6 components (environmental, applying MCDA approach Recommend preferred economic and social), time to performance matrix option and space aspects. In and stakeholder preferences addition, the Water Corpo ration developed an Figure 1: Conceptual relationships in the Susta inabili ty approach which convercs a Fram ew ork. triple bottom line analysis into an N PV and compares Sydney's water cycle management are the results with a conventional NPV. typical of the Australian water industry as a Problem Statement whole. Over rhe lase decade, water cycle management has become an increasingly challenging marketplace of ideas. Citizens have demanded increasingly higher environ mental perfo rmance from their water service providers, while governments demand greater fi nancial efficiency and the service providers cope with population and climatic pressure. To use Sydney's systems as an example of chis, Sydney Water has been required co reduce n utrient d ischarges, entailing investment on sewering d istricts with septic systems, imp roving telemetry, pumping statio n renewal and the construction of a massive undergro und sewer overflow storage. The government has forced Sydney Water co trade as a corporatised business, shed staff and improve irs p rofitability. In the last ten years, the organisation has added half a million customers and experienced one rhe worst d roughts on record, which climatologists believe to be related co global climate change (Karoly et al., 2003). To cope with the pressu res bearing on Sydney Water, particularly population growrh and higher standards, capital works expenditure by the organisation reached almost fou r billion dollars in chat time perio d (Sydney Water, 1999; Sydney Water, 2000; Sydney Water, 2005) . These examples of pressures on

84 NOVEMBER 2006 Water

Ar rhe same rime, the range of practical info rmation cools and planning app roaches available co water cycle managers has expanded, including strategic environmental cools such as life cycle assessment, health risk methodologies like quantitative microbial risk analysis, cost assessment techniques like life cycle costing and approaches co p ublic engagement like choice model ling (Blarney et al., 1998). Under these circumstances in which rhe variety of practical, political and in tellectual influences on water cycle planning has grown, managers are looking for clarity on the best ways co plan for che future development of their water, sewerage and stormwacer systems. This means taking a holistic, multidisciplinary app roach which cakes the interdependencies between aspects of sustainability in to account.

Development of a Response A consortium of researchers from the Centre for Water and Waste T echnology, the Schoo l of Civil and Environmental Engineering (UNSW, Sydney), the Sustainable Water Division of the NSW Department of Commerce (Sydney) and Chalmers Industriceknik (Chalmers University, Sweden) worked together for che Water Services Associatio n of Australia co develop a sustainability fra mework for

Journal of the Australian Water Association

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evaluating urban water systems. T he objective of the project was co develop a common methodology for evaluating the overall sustainability of alternative options for u rban water systems. T h is includes largescale options for cities as well as configu rations of water sensitive urban developments or single high rise develop ments. In particular the project aimed for a common methodology for evaluating overall sustainability of alternative options for u rban water systems, noting the range in al ternacive tools and approaches currently being used. This article describes the outcomes of the project.

Components of the Framework Based o n a survey of best p ractice and li terature review, a Sustainability Framewo rk was developed with six principal phases connected via an iterative process. T h is framewo rk was particularly inspired by the UK SWARD project (Ashley et al., 2004) and is summarised in Figure 1. To a varying extent, it is important chat in each phase, the plann ing process fo llows both an analytical and participatory approach (see Table 1). By ch is we mean chat an analytical framewo rk should be fo llowed because it provides a rigorous structu re and a sense of p rogress cowards the ultimate goal. But participation is just as important as having a good framework and cools. The Sustainability Framework emphasises the inclusio n of direct engagemen t with stakehold ers from the first phase of project develo pmen t. Exactly who the relevant stakeho lders are and how they may get involved in the plan ning process has co do with the scale of the problem and its potential sol ution.

Phase 1 - Framing the problem and objectives Ir is quite probable there may be a wide variety o f perspectives on the challenges facing a particular water system. There may even be competing o bjectives withi n a single scakeholder's perspective. In analytical terms, defin ition of the problem and the solution objectives is needed. Defi nition of the objectives of the project should include affected stakeholders, selection o f participants and the intended use(s) of the results, as well as including


technical features

discussion on the initiator/driver(s) of the project. This is the basis of the legitimacy of the whole process. Consul tation of stakeholders (including - even especially the public) is increasingly recognised as vital to ensuring successful implementation of water management systems (Creighton, 2005 ; Morrison, 2003). Three broad reasons for prioritising stakeholder engagement and participation are (Bush et al., 2005; Meadowcroft, 2004): Cognitive: allowing wider participation allows a wider range of knowledge to be brought to bear in a complex process. Strategic: consulting stakeholders at an early stage, and throughou t the project, makes it less likely they wi ll oppose the project (Carson and Gelber, 2001 ). Behavioural: sustainability calls for a realignment of attitudes and practices by water users. Participation in the planning process is part of this realignment. Participatory processes that may be usefu l in th is phase incl ude the creation of a steering co mmittee (possibly with selected members of the public), value management studies, market surveys and public meetings. In addition to orga nising these participatory processes, it may be worthwhile to in form a wider public about the existence of such participatory processes. Participants might include property developers, representatives of water, consent and other government authorities, futu re residents, politicians and representatives of community organisations. Phase 2 - Generation of preliminary options

A preliminary list of options should include conventional and al ternative options that may not be co mmonly accepted currently, but which may become attractive in the future under changed conditions. Analytical procedures for improving options generation, incl uding brainstorming, lateral thin ki ng and backcasting, can all be useful here (Mitchell and White, 2003). The op tions should be specified with enough detail to permit the subsequent cu lling phases. It may help to consider outcomes which are not wanted, prior to any brainstorming of options. Phases 1 and 2 will both draw out the values of the various parties represented in the process, which may be documented to facilitate discussions in subsequent phases. A diverse gro up of stakeholders should participate in this phase. Many options may already be on the system operator's table as a consequence of previous studies and representation from community and industry groups. Nevertheless, it is not unlikely that new technologies, or the

Table 1. Stakeholder engagement activities by process phase and system scale. Phase

Processes

Participants

Scale'

l. Define problem

• Steering committee • Value management study • Market surveys • Public conversations • Reference to other studies, policies, planning controls, organisational goals

• Owner/developer • Water authority • Consent a uthority • [Future] residen t community • Relevant government departments • Relevant politicians

A A

• Document all assumptions and value sets used.

• Relevant co mmunity or environmental orga nisations

2 . Preliminary options

• Brainstorming , lateral thinking, backcasting, w orkshops, expert consultants, collaboration of a diverse group.

• Any of the Phase l porticipants w ith an interest in participating • Water management experts [from industry/academia)

M-L

3. Determine sustainability criteria & weightings

• Citizens' jury, deliberative panel, expert panel, 'Value-tree analysis', public conversations, etc.

• All stakeholders [i.e. see Phase l)

A

4. Screen options

• Simple absolute yes/no decision • Technical experts in consultation based on q ual itative assessment with the wider stakeholder group A [or quantitative i f values already known) against objectives a nd criteria already established . Identify if mitigation is possible, reassess.

5. Detailed assessment

• Whatever assessment tools ore available: LCA, LCC, MFA, etc. Surveys &/or focus groups. Identify if mitigation is possible, reassess ranking & normalisation of criteria.

• Locol engineers • Broader technical experts • Community participation for social impact assessment

6. Recommend preferred opti on

• Critical review of options & uncertainties, which for M -L projects may utilise multicriteria decision add tools.

• Senior engineer • Representative stakeholders well informed in the whole process [i.e. see Phase l)

& objectives

M-L M-L M-L L M-L A

s M-L

S-M

M-L

*Decision scale: S - small (e.g. pump/valve replacement) within on organisation; M - medium (e.g. trunk main) with external stakeholders; l - large (e.g. new subdivision with water services in a large city); A - any scale. moior

convergence of new ways of thinking and institutional development may offer something new to be considered. Participants would include participants in the first phase and water management experts from ind ustry and academia. Phase 3 - Selecting sustainability criteria

The sustainability criteria need to be practical for use in screening options in Phase 4 and for detailed assessment of the performance of shore-listed options in detail in Phase 5. The selection of cri teria is critical - they ought to cover five primary cri teria (economic, human health, environment, technical and social) and encapsulate the various co ntext-specific objectives identified in Phase 1. T hese five criteria may be considered a water-industryspecific en largement of the traditional "triple" bottom line. Secondary cri teria are also selected (see Table 2). Keeping the number of criteria to the minimum necessary to facilitate subsequent phases reduces the amount of work involved in using them and enables the stakeholders to

more easily see the influence of their values on the final result. However, the number and types of secondary criteria depend very much on the actual project planned. T he use of participatory processes for the development of an agreed set of sustainab ili ty criteria will add to the ultimate acceptabi lity of the final strategy. A uti lity may propose criteria it co nsiders appropriate, but stakeholders frequently have different priori ties and may feel outcomes based on the utility's criteria have no legitimacy. Processes such as citizens' juries, reference to a broad steering committee, consulti ng an expert panel and public conversations (Cole-Edelstein, 2004) can be useful in this phase. Participants would include participants from the first phase. Phase 4 - Screening of options

Pragmatism (costs, time and other constraints) allows only a few options to be developed and assessed in detai l (Phase 5). The pu rpose of Phase 4 is to reduce the length of the list of options to a nu mber

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chat can feasibly and thoroughly be assessed. Options can be eliminated by applying a "coarse screen" based on some minimum performance standards associated with a few key secondary criteria selected in the previous phase. Having an agreed set of criteria reduces che likelihood of the rejection of the most infeasible op tions causing controversy at this stage. Rejection of an option at this stage on accou nt of a clear criterion will allow persons with a strong attach ment to the option to consider modifications to it (for example carbon offsets might reduce the greenhouse impact but raise the cost of an option). In this way, following che Framework becomes both a process of selection and a means to offer directions for redesign. Redesigned options can then be considered during a second iteration of Phases 2-4.

Table 2 . Ex amples of primary and secondary c riteria. Primary criteria

Secondary criteria

Economic

Net present value Capital cost Lile-cycle cost

Human health

Human health risk - chemicals Environmental

Contribution to climate change Contributions to smog Contributions to ecotoxicity Reduction in natural landscapes Technical

Reliability

Outlook

Durability

Despite che progress made by condensing rhe necessary p hases into a framewo rk for che Australian water industry, the framework will only be fully successful when enhanced by fie ld application. Two particular needs have been identified to progress the framework.

Flexibility Social

Phase 5 - Perform detailed options assessment Performing a detailed assessment of rhe options should p rovide accep tably accurate quantitative and/or qualitative comparisons of rhe shortlisted options. It is during Phase 5 that various cools (such as LCA, EF, MRA, CRA, LCC ere.) are used to provide data on each of rhe agreed criteria chat req uired quantifi cation. (These tools are described briefly in Box 1.) The indicator results generated by che tools are normalised by selecting a reference point and weighting, or co mparing chem to aspirational goals set by the organisation or by the government. For example, in 1994 the NSW Government sec a goal of reduci ng waste deposited in landfills by 60% in 6 years. If such goals exist for several criteria, a distance-to-target approach can be used to normalise performance results. This will minimise bias during the evaluation in Phase 6. The derailed assessment should be performed by engi neers and tech nical experts. Naturally, where social impact assessment tools are applied, there will be a need for community participation in phase

5. Phase 6 - Recommend preferred option As with most complex decisions, the outcome is seldom made on che basis of a

Water

Energy consumption Nutrient burdens

Ideally, if rhe decision-makers have consulted adequately in the p revious phase, rhe coarse screening can be based on the criteria as developed, and only the technical expercs can manage the fourth phase, consulting if necessary with the wider stakeholder group.

86 NOVEM BER 2006

Human health risk - pathogens

understand rhe criteria racings from Phase 5, but co understand rhe impacts caused by variations in rankings, u ncertainty, and if necessary, weightings, so providing fu rther insight for the final recommendation . This phase should include senior engineers and representatives of the stakeholder group. Ir is important that such representatives are well informed about the preced ing phases - ideally, they should have been a part of all the participatory steps leading to ch is phase.

Affordability Employment generation Community acceptance Distribution of responsibility and risk Organisational capacity Public education

single measurement or by an individual. MCDA address chis issue by allowing stakeholders to use several criteria at the same rime. D ifferences in approaches to MCDA relate to how rhe stakeholders participate and how their preferences are captured in marhemarical terms. An overall assessment of each alternative is performed in the aggregation phase, which utilises a n u mber of 'educated' stakeholders in the process. A variety of different methods for aggregating the preferences exists, including the Linear Add itive model, Simple MulciAccribuce Racing Method, Strategic Advisor, Analytical Hierarchy Process, and approaches co synthesis using a single criterion or an outranking approach. These are discussed in more detail in Lundie et al. (200 5). The results are used to clarify why an alternative is better ranked than another. Sensitivity analysis is then required to cesc rhe influence of the various parameters co the final results. In the lase seep o f rhe MCDA process, recommendations are made on whether a selection of rhe best alternative can be made, or sorting the alternatives into different categories or ranking of rhe alternat ives. I n Phase 6, the final recommendation is made for rhe p referred op rion(s) to go ahead . All of rhe previous information collected during Phases 1-5 is clearly presented. In addition to the consolidated information provided on the five p rimary criteria from Phase 5, the stakeholders in Phase 6 should work through che data, possibly by way of a transparent MCDA tool. The goal here is not only to

Journal of the Australian Water Association

1. Field-testing. Ir is recommended chat the project ream work with agencies chat have: a. Existing data on 'good' and 'bad' examples of decisions mad e in order to undertake a retrospective 'field rest' of the Sustainability Framework; to identify how che agency could have handled the situation better and/or identify what is missing in che framewo rk; and b. New key project decisions within different Scares in order to ap ply che framewo rk to projects of varying scale.

2. Research. There are still significant data and procedural gaps inhibiting the success of the framework, incl uding: a. Identification of appropriate criteria, particularly to avoid 'double counting' of environmental and economic cri teria; b. Methods for normalisation of criteria and identification of aspirational goals for various criteria; c. Development of easy approaches to capture uncertainty in criteria and weigh t estimation, which can be carried forward when p resenting data in Phase 6; d. Adjustments to the framework to address (i.e. cake into account and also influence) organisational and institutional facto rs as well as p roject-specific o utcomes, and e. Identifying ways to institutionalise sustainability across the various agencies involved.

Acknowledgments The authors wish to acknowledge the fina ncial support provided via an ARCLin kage Gran t (LP0455742) from the


technical features

Box 1. Sustai nability tools for options assessment.

Economic: Life Cycle Costing Life Cycle Costing (LCC) methodology quantifies the finan cial coses over rhe life cycle of a produce or a service system. LCC attempts to quantify costs that occur throughout rhe entire life cycle to all stakeholders affected, such as manufacturers, retailers, users and waste managers. Therefore, LCC goes far beyond traditional financial assessments with very narrow systems boundaries, such as costs to a corporation. With regard to its application LCC is ar a relatively early stage of development compared with environmental LCA.

Human health: Microbial Risk Assessment M icrobial Risk Assessment (MRA) emerged as an analogue to chemical risk assessment and focuses on exposure assessment and a linked dose-response model to ascertain potential risks from waterborne pathogens. In Australia, the Disability Adjusted Life Years (DALYs) approach developed by WHO has been adopted. T he DALY accounts for the years lived with a disability plus che years of life lost due co expos u re to a hazard, chat is, to assess any ill effect by severiry and loss of expected life years.

Human health: Chemical Risk Assessment Applicatio n of quantitative risk assessment has occurred in urban water chemical risk assessments (CRA). In contrast to pathogens, we are exposed to a vast array of compounds from many different types of p roducts on the marker. An initial screening methodology has been proposed to identify compounds char migh t pose a threat in connection with the use of non-potable and potable waters. This method includ es chemical analyses; specifically developed analysis methods; toxicity measurements; hazard and problem identification and a qualitative risk assessment.

Environmental: Life Cycle Assessment Environmental life cycle assessment (LCA) is a tool to calculate and evaluate environmentally relevant inputs (resource demand) and outputs (emission to air, water & land) and their po tential environmental impacts of a p roduct o r service system over its enti re life cycle. Ir is based on a mass-balance Ptocess analysis o f alternative op tions, and uses models of regional and global environmental impacts.

Environmental: Ecological Footprint Ecological Footprint (EF) is principally a tool fo r assessing the consumption patterns of populations or economic enti ties. The output of the assessment is a single index showing th e area of land and water char is required to provide t he energy and material consumed by a person , a population, an organisation or an economy. Further models were developed to improve on che o riginal measurement wh ich address only the land used directly by che p roducer and omitted impacts of suppliers further up che entire production chain. EF has che advantage of being easy to communicate wich a wide aud ience, bu r disad vantages such as being in a less developed stare of international scandardisacion chan LCA.

Technical: Performance Modelling Depending on the types of water cycle management interventions being considered by the plan ning process, there may be differen t approaches to characterising the tech nical performance of competi ng alternatives. In general, criteria such as reliability and flexibility would be considered. Reliabil ity should be understood as the risk of downtime fo r equipment ou tside their usual maintenance schedule scheduled maintenance, and rhe costs associated with ir, would be assessed using the financial criteria, to avoid double-counting. Flexibil ity relates to rhe ability of the design to meet possible fu ture scenarios where rhe potential fo r augmentation or modificatio n of the original infrastructure will be helpfu l.

Social: Performance Modelling/Community Appraisal As with technical performance, the scope of the options and their characteristics wi ll defi ne the app ropriate approach co assessing their social performance. Statistics can be developed regarding the affordabiliry of an op tion (raking abili ty or willingness to pay into account). Employment creation is a social good which can be used as a parameter for option evaluation. T o some extent, the relative acceptability of options to the community, and the level of public understanding and awareness can be assessed from survey work, if the decision p rocess does not include b road com munity representation on a steering committee. But a participative process, including participatio n in MCDA as outlined in this framework, is arguably more effective for achieving social sustainability than feed ing quantitative social impact assessment data into a decision- maki ng process (Livingston, 2006). Qualitative indicators of the adequacy of risk d istribu tion between users and managers of the system, and che organisational capacity to manage particular options, are so metimes used as components of a sustainability assessment. Water Services Association o f Australia and the Total Environment Centre, and the extensive advice from the WSM steering committee associated with chis project.

The Authors Associate Professor Sven Lundie, Dr Greg Peters (g.perers@unsw.edu.au), Professor Nicholas Ashbolt and PhD candidates Elizabeth Lai and Daniel Livingston are all associated with the School of Civil and Environmental Engineering (UNSW, Sydney). Sven and

Greg work in the Centre for Water and Waste Technology.

References Ashley, R.; Blackwood, D.; Bulter, D.; Jowirc, P. (2004). Sustainable water services: a procedural guide. Sustainable Warer Industry Asset Resource Decisions Project. !WA Publish ing, London, UK. ISBN I 84339 065 5. A Wf ( 1996) Ecological and human healrh risk assessment of chemicals in sewage discharges to ocean waters. Produced by AWf EnSighr and Paramerrix Inc for Sydney Water Corporat ion. ISBN 07310 7 194 8.

Beavis, P. and Lundie, S. (2003). Inregrared environmental assessment of tertiary and residuals treatment - LCA in t he wastewater industry. Water Science and Technology, 47, (7-8), I 09- 116. Blamey, R. K.; Bennett, J. W.; Morrison, M. D.; Louviere, ] .].; Rolfe, ] . C. ( 1998).

Attribute Selection in Environmental Choice Modelling Studies: The Effect of Causally Prior Attributes; 7; School of Economics and Management, University College, The University of N ew South Wales: Canberra, October 1998, p 24. Bush, I., Gillson, A., Hamilton, M. and Perrin, M. (2005), Public participation - Drawing

Journal of the Australian Water Association

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NOVEMBER 2006 87


the boundaries, Water and Environment journal, 19(3), 181-188. Carson, L. and Gelber, K. (2001), Ideas for Community Consultation: A discussion on principles and procedures for making consultation work, (report prepared for) NSW Department of Urban Affairs and Planning, Sydney. Cole-Edelstein, L. (2004) . Consult, deliberate or empower? Water, Journal of the Australian Water Association 3 I (8):72-75. Creighton, J. L. (2005), What water managers need to know about public participation: one US pract itioner's perspective, Water Policy, 7(3), 269-278. Curcis, A. and Lockwood, M . (2000), Landcare and catchment management in Australia: Lessons for state-sponsored community participation, Society and Natural Resources, 13(1), 61 -73 . Dean, M.; Beavis, P.; Lundie, S. (2003). In

Comparing wastewater systems for a growing city, On-site '03 - Furure Directions fo r Onsite Systems: Best Management Practice, Armidale, NSW, 30 September - 2 October 2003, Patterson, R. A.; Jones, M. J. , Eds. Lanfax Laboratories, Armidale, NSW, p 8. EPA (2005) Strategic Advice on Managed Aquifer Recharge using Treated Wastewater on the Swan Coastal Plain. Bulletin 1199, Environmental Protection Authority, Perch, Western Australia, October, ISBN O 7307 6839 2. Grant, T.; Opray, L.; Sharma, A.; Grant, A.; Pamminger, F. (2006). In Life cycle assessment

ofalternative water and sewage servicing in Melbourne, Enviro 06, Melbourne, 9 - 11 May, 2006; Melbourne, p 8. H allmann, M.; Grant, T.; Alsop, N . (2003). Life

Cycle Assessment and Life Cycle Costing of Water Tanks as a Supplement to Mains Water Supply; Yarra Valley Wat er January 2003, p 88. Karoly D, Risbey J, Reynolds A (2003) Global Warming C ontributes to Aust ralia's Worst Drought. January 2003. World Wildlife Fund, Sydney. Livingsron, D. J. (2006), Institutions and

sustainbility with LCA- what role can life cycle assessment play in modern asset management?,

Decentralised Urban Water Management, Ph.D. Thesis (submitted July 2006), School of Civil and Environmental Engineering, U nivers ity of New South Wales, Sydney. Lundie, S.; Ashbolt, N.; Livingston, D .; Lai, E. ; Karrman, E.; Blaikie, J .; Anderson, J., (2005)

Sustainability Framework - Methodology for Evaluating the Overall Sustainability of Urban Water Systems, Centre fo r Water and Waste Technology, University of New South Wales. Lundie, S.; P eters, G.; Beavis, P. (2004) Life cycle assessment for sustainable metropolitan water systems planning - options fo r ecological sustainability, Environmental Science and Technology, 38(13), 3465 ii 3473. Meadowcroft, J. (2004), Participation and Sustai nable Development: modes of citizen, community and organisational involvement, In , Lafferty, W . M ., Governance for

Sustainable Development: The Challenge of Adapting Form to Function, Edward Elgar, Cheltenham, UK.

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88 NOVEMBER 2006

water

Journal of the Australian Water Association

~

Mitchell, C. and White, S. (2003) Forecast ing and backcasting for sustainable urban water futures, Water, Journal of the Australian Water Association, 30 (5):25-30. Morrison, K. (2003), Stakeholder involvement in water management: necessity or luxury?, Water Science and Technology, 47(6), 43-51. Narangala, R.; Trotter, N . (2006) In Seeking

Enviro 06, Melbourne, 9 - 11 May, 2006; Melbourne, p 8. NRMMC & EPH C (2005). Draft National Guidelines for Water Recycling. Managing Health and Environmental Risks. Natural Resource Management Ministerial Council, and Environment Protection and H eritage Council. Peters G .M . and Lundie S. (2002) Life-cycle assessment of biosolids processing options. journal ofIndustrial Ecology, 5(2)1 03-121. Peters, G. M.; Rouse, K. (2005). Environmental sustainability in water supply planning - an LCA approach for the Eyre Peninsula, South Australia, In Proceedings of4th Australian l ife

Cycle Assessment Conference - Sustainability Measures for Decision Support, Sydney, 23-25 February, 2005. Peters GM1 Rowley H V, Lundie S, Flint M (2006) Challenges and opportunities in LCA - the water industry example. Proceedings of 5th Aust ralian Conference on Life Cycle Assessment (accepted for publication) 22-25 November, Melbourne. Regli, S., Odom , R., Cromwell, J., Lustic, M., and Blank, V. (1999). Benefits and costs of the IESWTR. journal ofthe American Water Works Association 9 1(4), 148-158 . Soderberg and Kirrman (2003) MIKA Methodologies for Integration of Knowledge Areas. The Case of Sustainable Urban Water Management. Goteborg: Dept. of Builc Environment & Sustainable D evelopment, Chalmers University of Technology. Stenekes, N. (2006), Sustainability and participation in the governing of water use: the case of water recycling, Ph .D. Thesis (submitted March 2006), School of Civil and Environmental Engineering, University of N ew South W ales, Sydney. Sydney Water (I 999) 1999 Annual Repo rt. Accessed at www.sydneywater.com.au May 2006. Sydney Water (2000) 2000 Annual Reporr. Accessed at www.sydneywater.com .au May 2006 . Sydney Water (2001 ) Towards Sustainability Report 200 l. Accessed at www.sydneywater.com.au May 2006. Sydney W ater (2005) 2005 Annual Report. Accessed at www.sydneywater. com .au May 2006. Throgmorton, J. A. (1 991 ), T he Rhetorics of Policy Analysis, Policy Sciences, 24(2), 153179. WHO (2004) . Gttidelinesfor Drinking-water Quality Third Edition. Volume I. World H ealth Organization, Geneva. WSM (2004) Health Risk Assessment ofFire

Fighting from Recycled Water Mains. O ccasional Paper No. 11 - November 2004. P repared by Deere D. , Davison A., T eu nis P ., Cunliffe D ., Donlon P. for the Water Services Association of Australia. ISBN 1 920760 04 0.


technical features fereed paper

RAINWATER HARVESTING: REVEALING THE DETAIL S A Lucas, P J Coombes, M J Hardy, P M Geary Abstract The Probabilistic Urban Rainfall and wastewater Reuse Simulacor (PURRS v7.2), the Model for Urban Scormwater Improvement Conceptualisation (MUS IC v3) and Spreadsheet modelling cools were compared fo r evaluating rainwater harvesting strategies. In put data included climate files, suggested water demands and time-steps. Models were run with climate data of unequal duration and time-step, which highlighted significant differences between modelled outcomes. Using climate data of equal duration still resulted in major differences. The reasons for these differences are explained as a fun ction of rhe duration and time-step of climate data, the time-step and diurnal patterns of indoor/outdoor water demand and tank co nfiguration. Results imply that the length and time-step of climate inpu ts, the distri bution and time-step of daily water demand and rai nwater tank configu ration are significant faccors in robustly evaluating mains water savings for a range of Australian climates.

Keywords: modelling, water demands, time-steps, rainwater harvesting Introduction

Computer modell ing rools are often used co determine the mains water savi ngs gained from rainwater harvesting strategies. The models MUSIC (v3) by the Cooperative Research Centre for Catchment Hydrology (CRCCH , 2005) and PURRS (v7.2) by Coombes and Kuczera (2002), and the use of sp readsheets are methods currently employed in the water industry co evaluate rainwater harvesting strategies. Inputs commonly used in MUSIC, PURRS and spreadsheet methods are shown in T able J. Table 1 shows chat a range of time seeps and durations are used for both rainfall and water demand inputs co the selected models. It may be perceived that rhe time-seep and duration of these inputs have negligible impact on modelled outcomes. For example, modelling results have been reported without stati ng the duration of the rainfall series used (Mitchell et al, 2000; Liebman et al, 2004; Tanner and King,

Table 1. Common inputs to MUSIC, PURRS and spreadsheet methods used to evaluate rainwater harvesting strategies. Method

Rainfall time step (duration)

Other climate

Water demand Indoor Outdoor

MUSIC

6 minute (1 year template or construct template from provided long record)

Potential evapotranspiration (PET)

Daily constant

Annual scaled to daily by PET

PURRS

6 mi nute (long records as provided or DRIP model with choice of duration)

Dai ly min imum and maximum temperature

Monthly daily average with 6 minute diurnal pattern

Probabilistic climate dependent with 6 minute diurnal pattern

Spreadsheet

Daily (l to 20 years)

NA

Annual daily average

Annual daily average

2004) whilst ochers have employed one year of climate data (H allmann et al, 2003; Melbourne Water, 2004) . Constant daily water demand is also commonly applied to modelling rainwater harvesting strategies (Mitchell, 2000; McLean, 2004; Phi ll ips et al, 2004). We consider that for a robust evaluation of rainwater harvesting strategies the time seeps of both rainfall and demand are signi ficant factors. T his study has two parts. Firstly, ic endeavo urs to understand the relative rel iabili ty of the common use of MUSIC, PURRS and spreadsheets, which employ rai nfall records with different durations, co evaluate the performance of rainwater harvesting strategies in Adelaide, Brisbane, Melbourne and Sydney. Seco ndly, chis study evaluates the relative reliab ili ty of che selected models for estimating mains water savings using rainfall records of equal duration at each location.

Significant differences between modelled outcomes were observed. Method

T he reliabiliry of che common uses of MUSIC, PURRS and Spreadsheet models for estimating mains water savings derived fro m rainwater harvesting strategies was analysed by conducting continuous simulation in accordance with the criteria shown in Table J. The simulations were then repeated using rainfall records of eq ual

duration at each location co remove the impact of using rainfall records of di ffere nt durations on the results from the selected models. All simulations use water demands from 3 person households, a roof area of 200 m2 connected co rainwater tanks and rainwater tank sizes of 1, 2, 3, 4, 5 and 10 kL. Household uses drawn from the rainwater rank include outdoor, coilet, laundry and hot water demand, which was assumed to represent 85% of indoor demand and I00% of outdoor demand. Given chat MUSIC was originally developed co evaluate planning strategies for stormwater management and PURRS was created co evaluate che detailed design of rainwater harvesting strategies, the results from PURRS are used as a reference.

Climate data Climate data sourced from the Bureau of Meteorology (BOM) and provided in MUSIC and PURRS was employed in the "common use" simulations are shown in Table 2. T he simulations co evaluate che impact of using rainfall records of equal duration utilised BOM climate data provided in MUS IC as shown in Table 3. The BOM rainfall files provided in MUS IC (shown in Table 2) contained many sections of hidden missing data chat were not highlighted by che data analysis cool within the model. Subsequent detailed analysis of these files to prepare che rainfall records shown in T able 3 revealed the sections of missing data, which were removed from the records. Note chat PURRS BOM records had gaps removed before use.

Journal of the Australian Water Association

Water

NOVEMBER 2006 89


Table 2. Duration and length of climate provided with MUSIC (v3 ) and PURRS (v7.2). Location

Model

Rainfall duration

Years

Sydney Observatory Hill Adelaide Airport Melbourne Regional office Brisbane Airport Sydney Observatory Hill Adelaide Airport Melbourne Regional office Brisbone Airport Sydney Observatory Hill Adelaide Airport Melbourne Regional office Brisbone Airport

MUSIC MUSIC MUSIC MUSIC MUSIC MUSIC MUSIC MUSIC PURRS PURRS PURRS PURRS

1/1/1959 to 31/ 12/1959 1/1/1970 to 31/12/1970 1/1/195910 31/ 12/1959 1/1/1990 to 31/ 12/1990 31/7/1913 to 10/12/2001 13/1/1967 to B/4/2001 30/4/1873 to 30/ 11/2001 31/5/19491016/2/2000 3/1/19 13 to 31/ 12/1992 13/1/1969 to 17/12/1991 12/1/1925 to 28/11/2001 9/1/1950 to 14/2/2000

1 88 34 128 51 79 22 76 50

Description

Template Template Template Template Template constructed using provided Template constructed using provided Template constructed using provided Template constructed using provided BOM data BOM data BOM data BOM data

BOM data BOM data BOM data BOM data

Water demand T he total water demands used in each model at Sydney, Melbourne, Brisbane and Adelaide were sourced from Coombes and Kuczera (200 3) and are summarised in Figure 1.

Tank configuration The configuration of the rainwater tanks used in each model is shown in Figure 2. In each of the models rainfall was di rected from roofs via first flush devices with a volume of 20 L to the rainwater ranks. An initial loss of 0.5 mm was assumed from the roofs. In the PURRS model the tanks are topped up by mains water at a rate of 40 L/hr when the water levels were drawn below a minimum water level located 0.3 m from the base of the tank as shown in case A (Figure 2). The rainwater rank configuration shown as case B (Figure 2) was adopted in MUS IC and the spreadsheet because the use of daily water demand s does not allow direct sim ulation of the mains water top up process. In this situation it was assumed that the proportion of the rank volume below the minimum water level always co ntained mains water.

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PURRS Continuous simulation of the performance of rainwater tanks was co nducted in PURRS at 6 -minute timesteps using rain fa ll over periods depending on the location as shown in Table 2. PURRS employ climate dependent water demands derived from Figure 1 and a diurnal pattern to disaggregate water demand into 6minute time steps. Full derails on the use and operation of the PURRS model

Brisbane

Figure l. Indoor/outdoor water use for 3 person dwellings (Coombes and Kuczera, 2003).

Use of the selected models

90 NOVEMBER 2006

50

0.3

m above base

Figure 2. Configuration of tanks used in PURRS (A), a nd M USIC and Spreadsheet (B).

Table 3. Climate files used in each model to enable direct comparison. Location

Duration

Sydney Observatory Hill 3/1/19 13 to 31/12/1992 Adelaide Airport 13/1/196910 17/12/1991 Melbourne Regional Office 12/1/1925 to 28/1 1/2001 Brisbane Airport 9/1/1950 to 14/2/2000

Journal of the Australian Water Association

Years

79 22

76 50

Comment

Removed Removed Removed Removed

sections sections sections sections

of missing of missing of missing of missing

data data data data


technical features

water resou

refereed paper

~:II

can be found in Coombes and Kuczera (2001 ).

MUSIC v3 Climate data was selected fro m the meteorological templates and rainfall records p rovided in MUSIC. The one year climate templates that utilise 6-minute rainfall and the longer BOM 6 minute records were used fo r each location as shown in Table 2 . The MUSI C model structure used in this study is shown in Figure 3. U rban N ode I represen ts the roof area. T he roof area was designated as 100 % impervio us and the rainfall threshold was adjusted to mimic a first flush d evice of 20 l and an in it ial loss of 0. 5 mm. In the Rainwater T ank node rhe details of storage properties (tank size), o utfl ow pipe diameter (90 mm) and reuse properties (water demand) were set. Outdoor water demand was simulated using the "water demand scaled by PET" option and indoor water demand was modelled using the "daily demand" op tion. Mains water savings were calculated by subtracting the rainwater tank outflow from the rainwater tank inflow that was fo und in the "Statistics/All Data" directory a~er running the model. Water demand data from the PURRS simulatio ns were used to condition the water demand inputs to M USIC. Further detai ls abo ut the use of MUSI C (v3) are provided in the MUSIC User G uide (CRCCH , 20 05).

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A simpl e Spread sheet program was Rainwater Tank Size (kll established to simulate the performance of the rainwater tanks that co mprised a series of Figure 5. Res ul ts from use of climate records of equal duration at each location in simple water balan ce calculations based on models. the rainwater storage TY, on each day t which is resolved as a fun ction of the various tank sizes are as follows: lkL = 0 .61 kL, 2kl = 1.6 1 kL, 3 rainwater storage TY,_1 on the p revious day t-1 as follows: kL = 2.4 15 kL, 4 kl = 3 .22 kl, 5 kl = 4.0 25 kl and IO kL = 8.05 kl. Water d emand d ata from the PU RRS simulations were used to TY, = TY,_1 + HR, - OF, - MWS, (1) condition the water demand inputs to the sp readsheet. where HRt is the harvestable roof runoff, OF, is the tank overflow Results and MWS, is the daily mains water savings. T he harvestable roof runoff HR, is dependent on potential roof runoff RR, less roof Mains water savings resulting from the water industry's "common losses of 0. 5 mm and the first flu sh separation of 20 litres: use" of the models is shown in Figure 4.

HR , = { RR , -(200 x 0.0005 )- 0.02 , (m ' ) 0,

RR , 2!'. 0.095 Otherwise (2)

The daily main water savings MWS, were derived as a function of daily water demand DD, on the rainwater tanks using: DD 1 $ :V1-1 +HR ,- OF, TV1-1 + HR , - OF,, Otherwise

MWS , = { DD ,,

(3)

To account for the minimum water level of 30 0 mm and the overfl ow outlet diam eter of 90 mm in the Spread sheet, an available rainwater sto rage volume (kL) was calculated based on an area of l m 2 (x 1 m high) for a I kl tank and height of 2 m for larger rank sizes (using variable plan areas). Available tan k volumes for the

Figure 4 shows chat rhe use o f meteorological templates chat employ one year of rainfall in MUSIC resulted in an over-esti mation of mains water savings for Sydney and Brisbane, and an underestimatio n of mains water savings for Melbou rne and Adelaide in co mparison to the PU RRS results. T he use of meteorological rem plates based on the lo nger BOM records provided in M USIC resulted in a consisten t underestimation of mains water savings at each location. A proportion of the under-es timation of mains water savings can be attributed to the period of "hidden" missing data in each of the BOM records provided in M USIC. Results from the sp readsheet analysis reveal an under-estimation of mains water savings for Sydney and Melbourne, and an overesti mation of m ains water savings fo r Adelaide and Brisbane.

Journal of the Australian Water Association

Water

NOVEMBER 2006 91


The BOM files provided in MUSIC were analysed to remove missing data and to create climate files of equivalent duration for each location as shown in Table 3. The use of climate files of equivalent duration at each location in the models will eliminate the variability of mains water savings caused by the use of climate fi les of differing length. Results of the use of climate files of equivalent durations at each location in MUSIC, PURRS and the spreadsheet are shown in Figure 5.

-

Figure 5 reveals that the use of longer climate records which are free of missi ng data in MUSIC resulted in simi lar mains water savings fo r Adelaide and an underestimation of mains water savings at Sydney, Melbourne and Brisbane in comparison to the PURRS results . T he spreadsheet analysis using the same climate data was able to approximate the mains water savings for Adelaide and underestimated the mains water savings fo r Syd ney, Melbourne and Brisbane in comparison to the PURRS results.

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The mains water savings derived from the water industry's "common" use of MUSIC and spreadsheets fo r evaluating rainwater harvesting strategies are compared to the PURRS results in Figure 6. Figure 6 shows that analysis of rainwater harvesting using one year of climate data in MUSIC has over-estimated main water savings from 15% to 30% for Sydney and underestimated mains water savings from 10% to 15% for Melbourne, from 0% to 20% in Adelaide, and by about 10% in Brisbane. Analysis of rainwater harvesting over a period of a single year produces unacceptable errors in the assessment of mains water savings from rainwater harvesting. The use of longer BOM climates files as provided in the MUS IC analysis, including "hidden" missing data, has under-estimated mains water savings by 15% to 40% in Sydney, by 20% to 40% in Melbourne, by 20% to 30% in Adelaide and by up to 5% in Brisbane. Clearly the periods of missing data in the rainfall records has contributed to these differences. Analysis of the performance of rainwater harvesting using 18 years of climate data in a spreadsheet has over-estimated mains water savings by 5% to 40% in Brisbane and has underestimated mains water savings by about 30% in Sydney and by 45% to 50% in Melbourne. In Adelaide, mains water savings were over-estimated by 0% to 10% fo r tank sizes '.S 3 kL and under-estimated mains water savings by 0% to 5% for larger tank sizes.

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Discussion

92 NOVEMBER 2006

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The range of the under/over estimations produced by the water industry's common use of the models is considerable and rhe magnitude of these errors would be unacceptable for water planning and evaluation of rainwater harvesting strategies. These differences observed between the common use of models and the PURRS results are most likely a consequence of using climate records of different durations with missing data in some of the climate records. T he different treatment of water demand inputs, the time step of simulation and the configuration of the tanks used in the models will also contribute to the variability of results. The different climate durations and missing data in climate records was deemed to contribute to the observed errors and as such, cli mate files were truncated to provide relatively complete, long-term climate files in an attempt to reduce the observed differe nces between selected models. Results from analysis in the models using climate files of equal duration at the different locations are shown in Figure 7.

Journal of the Australian Water Association

Figure 7 shows that the diffe rences resulting in analysis using rainfall data of equal lengths are generally lower than those observed fro m the water industry's "common use" of the models. Analysis of rainwater harvesting using M US IC resulted in under-estimation of mains water savings by 15% to 5% in Adelaide and underestimation of mains water savings by 10% to 30% in Sydney and by I 0% to 20% in Melbourne. Differences of± 5% were observed for Brisbane. The analysis of rainwater harvesting using the spreadsheet results in an over-estimation of mains water savings of up to I 0% in Brisbane and under-estimates mains water savings by 20% in Sydney and by up to 10% in Melbourne. Differences of± 15% were observed for Adelaide. Although the magnitude of differences has been reduced by use of rainfall records of equal durations that have a minimum of missing data in the models, the magnitude of diffe rences remain unacceptable for robust assessment of rainwater harvesting. Nevertheless, the


results indicate that simulation of the perfor m ance of rainwater harvesting systems is critically dependent on the d uratio n of rainfall used in m o dels. The selection of rainfa ll records that are complete and h ave an ad equate d uration is important for mo re reliab le sim ulation of rainwater harvesting. Variatio n of the magn itude of errors between locations also indicated that sim ulation of rainwater harvesting was dependent on the ab ility of the m odels to account for the climate regime at each location . Reliab il ity of a model in different cl imate regimes will be dependent on the time step of simulation, treatment of water demand inputs and the represen tatio n of the configu ratio n of rainwater tanks. At a location that is su bject to a greater proportion low intensiry rain fa ll events and/o r an even d istri bution of rain fa ll (such as Melbourne and Sydney), models that o perate at a d aily time step are more likely to under-estimate mains water savings because th ey can not account for intra-daily water d emands that occur d ur ing rainfall even ts. For example, Figure 7 shows that the Spreadsh eet and MUSI C simulations that utilise d aily water demand an d si milar

tank configurations have under-estimated mains water savings at Melbou rne and Sydney.

At the Adelaide location, for tan k sizes greater than 2 kL, the Spread sheet and MUS IC models produce similar results that trend cowards u nder-estimation of m ains water savings with larger tan k sizes. This result is likely to be d ue to lower ann ual rainfall dep th , winter rainfa ll d istribution and su mmer water dem and that has highlighted di fferences between models. H owever, considerable differences between MUSIC and the Spreadsheet were observed for smaller tank sizes in Adelaide. The 6 m inu te rai nfall inpu ts to the rank coupled with daily demand extract ions from the ta nk results in an over-esti mate of overfl ows from the ra nk and therefore under-estimate water savings fro m the smaller tanks. In contrast, the use of daily rainfall and water demand in the Spreadsheet will u nderestimate tank overflows, thus overest imating ma ins water savings for smaller rank sizes. Figu re 7 highl ights the need to uti lise both continuous rainfa ll and water d emand (6 -mi nute), in conju nction with realistic di urnal water use patterns, in ord er to reduce these errors for sm aller tan k sizes.

At the Brisbane location, for tan k sizes greater than 2 kl, the Sp readsheet and MUSI C m odels p roduce similar results that trend towards over-estim ation of mai ns water savings for larger tank sizes. This result is likely to be due to h igh er ann ual rai nfa ll depth, available rank storage and sum mer rainfall d istributio n that overwhelmed any di ffere nces in the mo del process. Nevertheless, for smaller tank sizes in Brisbane considerable d ifferences between MUSI C and the Spreadsheet were observed. T he difference between Spread sheet and MUSI C simulatio ns was the use o f 6-mi nute rainfall and a PETscaled ou tdoor demand in M US IC. The confi guration of MUSIC utilises 6-minute rainfall inpu ts to the tank and daily d emand extractio ns fro m the tank, resulting in an over-estimation of tan k overflow and therefore under-estimation of mains water savi ngs from sm aller tanks . In contrast, the u se of daily rainfa ll and water demand in the Spreadsheet u nd er-estimates tan k overflows, thus over-estimates m ains water savings for smaller tank sizes.

PURRS u tilises 6-min ute rainfall, 6- m in ute water demand based on a diurnal water pattern and a climate dependent outdoor use model. Figure 8 conceptualises the d ai ly

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Journal of the Australian Water Association

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Sales & Rentals

NOVEMBER 2006 93


technical features

water use demand patterns as used in the selected mod els. T he use of a d iurnal pattern (su ch as PU RRS) is mo re likely to realistically sim ulate water dem and from rainwater tanks. Figu re 8 highlights the significant variation in water demand fro m tanks using MUSI C and a constant water demand, wh ich is simu lated with the Sp readsh eet. M odelled resul ts imply the significance of sim ulating tan k con fig uratio ns at 6-m inu te tim es-steps to capture intra-daily dem and for robust results. Fo r example, if rain fa ll enters the tank in the m orni ng it is immediately ava ilable fo r use and as mo re water is d rawn from the tank there is increasing rank volume ava ilable to capture further rain chat day. Also, the use of a diurnal water use pattern is mo re real istic than using constan t daily d emands, as rhese patterns govern in trad aily available tank vol ume. Therefo re, co ntinuous sim ulation of rain fa ll, water d emand and diurnal water use patterns must be co nsidered fo r robustly evaluat ing rainwater harvesting srraregies . I n addition , a non -paramereric nearest neigh bourhood scheme has been developed co create syn thetic rainfall reco rd s rhac can b e used in con tinuo us simulatio n m od els such as P URRS (Coombes, 20 04). T he m ethodology relies on the use of a target sire with a daily rain fa ll reco rd , and nearby p l uviograph record s char are used as reference files to disaggregate the daily rain fa ll into a continuous series of storm events and dry period s. T his method has been successfu lly verified against observed pluviograph records at Brisbane Airport, Sydney A irpo rt and W elli ngto n Research S tation , with good re plication ofIFD cu rves and dry period s, indicating char reliable synthetic rainfall record s were p rod uced (Coo mbes, 2004) . The practical consideratio ns of selecting an o p timu m size tan k fo r a given develop m ent o r sub division will depend o n rhe physical

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limi tatio ns of rhe sire (]or-size, slop e, etc), com parative life-cycle costs (co mpared to centralised water system s) and rhe social/cost/environmental im pacts analysed d uring th e integrated water cycle management (IWCM) process. As such, rhe derai l requ ired to comment further on affordability, life-cycle costing and secu rity are o utside the scope of rhis paper however th e article by Coom bes in Water (M arch 2005) h igh lights rhe com plexity in analysing scales of water management and rhe solutions preferred by the water au tho rit ies.

The PURRS, MUSI C and Spreadsheet modell ing cools have been d iscussed in rhe co ntext of how rhey are common ly used in rhe water industry to eval uate rainwater harvesting strategies. Sign ifican t d ifferences were observed (-50% to +60%) . Even when climate files o f eq ual du ration were used in each m od el, majo r differences still existed (30% co + I 5%) . The selection of rain fa ll records chat are complete and have an ad equate d uratio n is importan t fo r mo re reliable simulatio n of rainwater harvest ing, as well as the m od els' ab il ity co account fo r variable cl imate regimes. The d ifferences between models were exp lained in terms of the d u ratio n and rime-seep of climate data, use of a diurnal pat tern fo r water demand and simulating tank co nfiguration ac a 6m inu ce t ime-step. Reducing time-seeps to mimic realistic fl ows and using a derai led tank con fig uration and diu rnal water use pattern co sim ulate ran k d rawdow n promote robust evaluation o f rainwater harvesting strategies. Boch M U SI C and the Sp readsheet were u nab le to reliably simulate available tank vo lume d ue to inadequate intra-daily water demand cime-sreps, particu larly for smaller tanks sizes.

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94 NOVEMBER 2006 Water

Australia. C oombes, P. J. and Kuczera, G. (200 I). Rainwater tank design fo r water supply and stormwater management. Stormwater

industry Association 2001 Regional Conference, Port Stephens, NSW , Australia. C RCCH (2005) . M USIC (v3) User G u ide. M US IC Development Team. C RC for Catchment Hydrology, Monash Universi ty, Victoria, Australia. Liebman M ., Garraway, E., Bain, L., Brown, M . and Dall mer Roach, L. (2004) H ow sustainable are stormwater management targets?, Proceedings ofthe 2004 international

Conference on Water Sensitive Urban Design, Adelaide, Australia. McLean, J. (2004) Aurora - Delivering a Sustainable Urban Water System for a New Suburb, Proceedings ofthe 2004 international

Conference on Water Smsitive Urban Design,

Accounting for Water Contaminants in Urban Areas, 10th World Water Congress,

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Adelaide, Australia. Phillips, B.C., Wade, W., Howa rd, T. and Breen, M. (2004) Towards the I ntroduction of Rainwater Tanks across the C iry of C alou nd ra, Queensland, Proceedings of the 2004 l nternationa.l C onference o n W ater Sensitive Urban Design, Adelaide, Australia. T anner, C and Ki ng, A. (2004) Integrated W ater Management At 599 Payne Rd, T he Gap, Proceedi ngs of the 2004 Sustainable Water in the Urban Environ ment, Brisbane, Aust ralia. Mitchell, V .G ., Gray, S. and Farley, T. (2000)

The Authors

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Management Group, School o f E nviron mental & Life Sciences, at the U niversity of Newcastle, em ail Sreven .Lucas@newcasrle.edu.au; Associate Professor P J Coombes (integrated warer system s) and Dr PM Geary (on-s ite wastewater systems) are sen ior m embers of this gro up. M J Hardy is a doctoral studen t with the U rban Water Research Gro up, School of E ngineering, at the U n iversity of N ewcastle.

Journal of the Australian Water Association

Melbourne, Austra.lia. M elbourne Water (2004) Revised MUSIC Input

Parameters Guidelines. H allmann, M. , G rant, T. and Alsop, N. (2003) Yarra Valley Water - Life Cycle Costing of Water T anks as a Supplement to Mains Water Supply, Centre for Design at RM IT Universiry, Melbourne.


.fereed paper

PROJECT DELIVERY AND COMMISSIONING: AN INTEGRATED APPROACH Z Slavnic Abstract This paper provides an insight into a project delivery process from the commissioning point of view where commissioning goes hand-in-hand with ocher phases from the project on-set throughout the facility acceptance phase.

PLANNING

.0. DESIGN

.0.

I

Introduction Commissioni ng has traditionally been viewed as a distinctive phase of a project del ivery process, i.e. a p hase at the end of co nstruction works. Ir serves different purposes, depending on which sid e of the fence one is looking from. For contractors, it is mainly co handover a facility and co obtain a project completion certi ficate. For end-users, it is co acquire a fu lly operational asset char meets their long-term O&M needs. Ir is felt that chis traditional approach rarely provides the best outcomes co either parry. From the contractors' point of view, the challenge is to fu lly integrate commissioning activities into design and construction p rocesses. From rhe end-users viewpoint, it is co eliminate the fence, i.e. co ensure char both parries jointly work in handing over an asset which can be managed in the most cost-effective way. Although it briefl y addresses the latter issue, rhe paper mainly discusses the challenge from the contractors' perspective. Therefore, the paper examines an integrated approach where a commissioning agent, as a member of the project delivery ream, provides inp ut from d esign th rough to constructio n and handover, and beyond, co the benefits of b oth end-users and con tractors as well.

Traditional Commissioning Concept The verb to commission, as explained in most dictionaries, means to make or become operative or operable. In the engineering terms commissioning can be defined as a systematic process for achieving, verifying and documenting rhar rhe performance of a facil ity, complete with its structures, plant, equipment, and systems, meets rhe intent of design and the end-users needs in respect to

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Figure 1. Traditional Project Delivery Method.

A commissioning agent, as a member of the project delivery team, provides input from design through to construction and handover. operability, maintainab ili ty, safety, protection of environ ment, ere. In general , delivery o f any project will encom pass several distinctive phases from a project in itiation through co design, construction and fina l handover. T raditionally, commissioning has been seen as a stage at the end of rhe consrrucrio n phase (Figure 1) or sometimes, d ep ending on rhe project size, as a sub-phase of the co nstruction. Comm ission ing usually entails establishment of a commissioning ream at the point in ri me when const ruction works

is almost complete, fo llowed by assignment o f responsibilities before carrying our various resting activities in accordance to inspection and rest plans (ITPs) and/or resting p rocedures. T he commissioning ream, led by a commissioni ng manager, is basically charged co conduct various checks of plant and equipment operation, funcrio ning and performance, as well as conducting the necessary training of the end-users personnel. In addition, fi nal documentation, such as O&M manuals, asconsrrucred drawings, ere, is furni shed co rhe end-users to enable chem ongoing management of rhe asset once h anded over. T his app roach exposes a fundamental flaw in rhe project delivery process. N amely, the input from commissioning specialists is sough t after design had b een carried our and with co nstruction works nearing completion, if not already fully completed. Under su ch circumstances, any su bsequent changes, as may be, and frequently are, identified d uring commissioning are therefore associated with significant costs and lengthy delays in p roject completion. This often results in implementation o f solutions that are partial and compromise needs of end-users, who ultimately pay the price due to higher operational and maintenance expenditure required throughout the eco nomic life of rhe asset acquired.

Integrated Commissioning In order co maximise benefits to end-users, comm issioning should ideally extend through all phases of a project d elivery, ideally from its planning phase through to operation of the facility during the warranty period. This is particularly true for projects: • where scope and construction works are of a complex narure; • new treatment tech nologies are employed; • process proving period is included; and • projects with operational phase, such as BOO and/or BOOT schemes. This approach requires a commissioning entity, e.g. commissioning manager or a

Journal of the Australian Water Association

Water

NOVEMBER 2006 95


technical features

project delivery faci lity management specialist, at the earliest stages to oversee project development. The main role of com missioning entity is to provide technical direction throughout d esign d evelopment and d uri ng execution of const ruction works to ensure operation and maintenance objectives are taken into acco unt, as well as to facil itate start-up of the treatment plant. As shown in Figu re 2, commissioning activities during the each phase of a proj ect are intended to ach ieve the following project specific o bjectives:

Planning • Provide initial commissioning plan and methodology as part of the project plan; • Provide preliminary commissioning p rogram for incorporation into the project p rogram;

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COMMISSIONING PROCESS

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• Assess o r revalidate required co mmissioni ng resources; • P repare or refine commissioning budget; • Generate or revalidate process design data through ope ration of pilot pla nes. This is particularly relevant when edge technologies are intended to be used , such as biological nutrie nt removal, membrane bio-reactors, etc.

Design • Provide a design review with a focus on operability and maintainabili ty. T his is best carried out in a team environment such as design wo rkshops a nd HAZOP studies. • Review design to fa cili tate com missioning process itself. This includes provision of equipment that is normally not required for day-co-day operation, but co enable smooth and timely commission ing. • Ensure that commissioning and O&M requirements are adequately reflected in enquiry documentation for tendering purposes; • Ensure tender co nformance w ith commissioning and O&M requirements during tender assessment and post-tender negotiations .

Construction • Form commissioning team and ensure everyone understands their roles and responsibilities; • Develop final com missioning plan, including sub-pla ns for commissioning of each unit process, in co mpliance wirh design inte nt; • Ensure ITPs a nd testing procedures are developed and adequate for commissioning tasks; • Develop overall process/facility O&M manual; 96 NOVEMBER 2006

Water

~ FACILITY ACCEPTANCE

Commissioning plan Commissioning team Commissioning procedures and ITPs O&M manuals Training plan Checks for accessibility Witness/review factory testing

-----------------------------• •

Pre-commissioning checks Plant/equipment performance tests • System performance tests • Functional performance tests • Operator training Commissioning Report • Start-up

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Review for operability Review for maintainability Design for commissioning Define commissioning for tendering and tender assessment

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Process & equipment troubleshooting Fine tuning and process optimisation • Standard operating procedures • Lessons learned

Figure 2. Project Delivery and Commissioning Process.

• Ensure suppliers O&M manuals a re not generic in natu re, but specific co plane and equipme nt installed;

• Ensure plant a nd equipment operational checkouts are carried out;

• D evelop training plan covering the en dusers O&M needs;

• Veri fy and document prope r operation, functioning and perform ance of plane, equipment and systems (i.e. unit p rocess);

• Inspect construction works for adequate access and operability and maintainability n eeds of end- users personnel;

• Verify performance of the treatment faci li ty through start-up and fu ll pro cess establishment.

• Witness and review facto ry testing of key equipment includ ing testing of SCADA a nd PLC logic;

• Ensure O&M personnel are provided with adequate training and operation and maintenance documentation for the ongoing faci li ty ma nagement after comp letion of the construction works. T his may include O&M manuals, unit process guidelines (UPGs), standard operating procedures (SOPs), o perating philosophy, control philosophy (functional description specification), etc.

• Arrange sampling and analyses by an accredited laboratory .

Facility Acceptance • Ensure relevant statutory approvals a re obtained; • Ensure plant a nd equipment are installed in accordance to manufacturer instructions a nd good engineering practices;

Journal of the Australian Water Association

• Provide commissioning repo rt, derailing performance , co ntrol a nd instruments set


technical features

project delivery points, alarm settings, etc, for later reference by the O&M team. • Ensure relevant O&M documentation is updated based on implemented modifications to the plane, equipment and control systems.

Post-Acceptance • Provide and ensure support to O&M personnel in equipment and process troubleshooting during d efects liab il ity period and /or process proving period; • Assist with p rocess fine-tun ing and optimisatio n; • Refin e/update U PGs and SOPs, as requi red, based on process fi netuning/optimisation; • Provide feedback to the project team (designers, constructors) o n things that are done well, but more importantly on areas that could have been done better. It is believed th at no project sh ou ld be closed withou t carrying ou t the lessons learned, as that exercise enables us to learn from our mistakes and deliver better next time.

Benefits of Integrated Commissioning

users should have a much greater role. This is a matter that d irectly concerns them in the short run, but more importantly on a long-term basis, i.e. throughou t the economic life of the asset to be acquired. T herefore, the end -users should take the lead to maximise benefits of th e integrated commissioni ng. For example, in order to accomplish that objective, a senior enduser's O&M specialist could be made a member of the contractor's team from th e project inception to work closely with the commissioning agent. It is believed the integrated commission ing app roach, coupled with the tender operab ility and maincainabilicy criterion (see 'P roject Delivery: An O &M Perspective', Water, Volume 32 No. 8, D ec 2005), would ensure best value for money in che lo ng term to the benefits of all parties invo lved , and che communi ty at large.

Conclusion T he integrated com missioni ng would ensu re an essential lin k b etween p roject delivery ream and che end-user's O&M

The need for the integrated app roach stems from the reco gni tio n that co nsulting and construction companies have know-how in design and co nstruction means/ method s respectively, but most have inadeq uate expertise in start up of treatment facil ities and aspects related to day-co-day O&M management. For the co ntractors, the integrated approach wou ld result in the fo llowi n g majo r benefits:

• Min imal delays throughout project execution due to less rewo rk after complet ion of construction works. This sh ould also improve the project bottom line.

• Lower asset life cycle costs; • Enhanced safety due to treatmen t facility being O &M fr iend lier. The D &C project delivery method requires that the end-users, to a great extent, give up control not only over design and co nstruction, bu t also over commissio ning. T here is nothing wro ng with this, as this approach provides mutual benefits, provided that both parties understand the delivery process and that the end-users fi rst, understand risks involved and second ensu re adequate oversight throughput the project execu tion. However, when it comes to com m issioning, it is felt that the end-

Acknowledgment The author wishes to than k Mr Sam Mahendra o f Syd ney Water Corporatio n for providing valuable comments on the subject.

The Author Dr Zoran Slavnic (PhD, M BT, M Eng, BEng) has almost 25 years experience in design, co nstruction, commission ing and O & M in the water industry, and has recently joined Barclay Mowlem. Email: zslavnic@bmcl.com.au

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• Improved client-co ntractor interface, hence improved relationship which raises prospects for follow-on works;

The benefits to the end-users would also be significa nt:

p lant team throughout a project execution. Ir would also ensure char resting and performance verificatio n is carried our in line with the intent of design with minimal delays. In addition, O&M needs would be captured up-front, which is crucial from the end-users viewpoint. Integrated commissioning is also, without any d oubt, in the interest of constructio n companies in D &C, as it fac ilitates implementation of design changes before construction works actually take place and, more importantly, improves relationship with the client.

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Journal of the Australian Water Association

water

NOVEMBER 2006 97


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MANAGING STRESS AND PREVENTING PROBLEMS The efficiency and reliab ility of cooli ng water systems are crucial in optimising your plane's operation and reducing rhe Total Cost o f Operation (TCO). Every cooli ng water system is under stress. When stress is coo high, scale, corrosion and fou ling result. W hen st ress is coo low, water and chemicals are wasted. Nalco's 3D TRASAR is a stress management program char integrates innovative chemistries, advanced software, scare-of- the-arr equipment, data management and remote communication along with new service cools. Ir optimises cooling system stress co minimise TCO and prevent operational problems. T his program is ideal when: • equipment rel iability is paramount; • upsets and process leaks threaten system degrad ation ; • hard ness variation is common; • phosph ate concenrrarions are variable; • system load ing varies; • gray water is used as makeup;

Water Business aims to keep readers alert ro business news and new product releases within the water sector. Media releases sho u ld be emailed to Brian Rault at brian.rault@halledit.com.au or Tel (03) 8534 5014. AWA wishes to advise readers that Water Business in for mation is suppl ied by third parties and as such, AWA is not responsible for t h e accuracy, o r otherwise, of the infor mation submitted. • pH control is poor; • biocide feed is inconsistent; • bio-popularions vary or the system is p rone to microbial contamination. A dedicated representative will work with you on site hands-on to develop sustainable sol utions chat meet you r cool ing system requ irements. For a reliable and efficient cooling water system, Nalco will concentrate on three key areas: mechan ical , operational and chem ical to contro l corrosion, scaling and bio-activity.

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POTABLE WATER'S ANSWER TO PORTABILITY There is a frequen t requi rement for measu ring d rinking water p arameters accurately, p recisely and easily in the fie ld . T he measurement of photo metric parameters like ch lorine, fluo ride, aluminiu m, iro n or manganese in co njunction with a turbid ity measurement and a pH measu rement has in rhe past, been a cumbersome task in the field . Three or more separate instrumen ts are required to perform the tasks. More st ringent controls and regulatio ns fo r these parameters and the time constraints an d associated costs in p erfo rm ing rhe req u ired tests open up th e door to new and innovative technologies. The n ew and uniq ue instrumen t from WTW, the pH otoFlex T urb, offers an ideal solution to the drinking water markers aro un d rhe world. Ir is rh e fi rst meter of its type char offers trad itional p H measu rement via an electrode of cho ice, plus turb idity. I r is a full y functional photometer capable of measuring up to sixty parameters photometrically in rhe fie ld. Most important d rinking parameters determined photometrically require min imal samp le preparation and in almost all cases are easily perfo rmed in the field . T he pHotoFlex Turb from W TW is supported and p rogrammed with all Merck reagent and cell test kits, ensu ring safe and so und chem istries are available du ring the analysis. The photometer makes use of a h ighly robust optical system, thus being suitable fo r mobile app lications. T he LED technology employed, which also incorporates fil ters for six wavelengths, has extremely low power consumption.

WaterGEMS®V8 MULTI-PLATFORM WATER MODELLING Bentley WaterGEMS VS brings the only platform-independent solution to the world of water distribution modelling, allowing engineers to build, analyse, and map water distribution models without being anchored to a specific engineering design or geospatial platform. For more information, see the inside front cover of the November issue of Water Journal, visit www.bentley.com/A WA, e-mail anz.marketing@bentley.com, or call +61(0)39699 8699.

98 NOVEMBER 2006

Water

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Water Journal November 2006  

Water Journal November 2006