Water Journal February 2008 by australianwater

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water Journal of the Australian Water Association

Volume 35 No 1 February 2008

OPINION AND INDUSTRY NEWS OPINION Contemporary Water DBarnes, President, AWA Valuing - and Pricing - Our Water TMollenkopf, CEO, AWA My Point of View Howard Jones, Chair, Murray Wetlands Working Group CROSSCURRENT International, National, States, Industry, People in the News AWA NEWS Eureka Prize for Water Research and Innovation; Meander Dam Delivers for Dairy Farmers in Northern Tasmania AWA EDUCATION Water Education Network; Water Industry Capacity Development; AWA Master Classes 2008 YOUNG WATER PROFESSIONALS AWA MEMBERSHIP NEWS New Members

s 6 8 14 18

24 26

TECHNICAL FEATURES (! Â·,] indicates the paper hos been refereed I SUSTAINABILITY OF URBAN WATER SYSTEMS Urban Metabolism - Improving the Sustainability of Urban Water Systems New ways of thinking FPamminger, S Kenway RECYCLING Iii Virus Reduction by Chlorination for Class ARecycled Water Determining Ct values for free chlorination of viruses in BNR effluent GHaylock [i] Opportunistic Pathogens in Drinking and Recycled Water Distribution Systems It is important to adopt a pragmatic approach to their incidence within a distribution system MVStorey, CEKaucner, MLAngles, J RBlackbeard, NJ Ashbolt [i] Water Reuse Projects: The Role of Community Social Infrastructure Success depends on community participation GBKeremane, J McKay DECENTRALISED SYSTEMS [I] Decentralised Water Supplies: South-east Queensland Householders' Experience and Attitudes Three groups with different motivations AGardiner, PSkoien, TGardner Alternative Indicators for Detection and Quantification of Faecal Pollution Distinguishing human from animal pollution WAhmed, AGoonetilleke, TGardner [I] Urine-Separation and Reuse Trial Urine collection as in Northern Europe: is it feasible here? CBeal, TGardner, WAhmed, CWalton, DHamlyn-Harris CENTRIFUGES ~ Comparing Centrifuge Capacities for Sludge Dewatering Key scaling parameters to compare machines on a common basis KCodee, AHertle COMMUNITY CONSULTATION [i] Customer Segmentation in the Residential Sector Applications for targeted products, campaigns and tailored water conservation programs KLa, KVino! WATER TREATMENT [ii Disinfection By-Products: An Australian View Brominated haloacetic acids ore potentially more toxic than THMs MDrikas, PSinger, CChow, MHolmes

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WATER BUSINESS NEW PRODUCTS AND BUSINESS INFORMATION - SPECIAL FEATURE: PIPELINES ADVERTISERS' INDEX

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OUR COVER Decentralised water and wastewater systems have long been used for residences distant from the main urban centres, b11t there is a move for their application in both new and retro urban developments, with rainwater tanks being subsidised by the major authorities. Decentralised wastewater systems are also benefiting from application of new technology. SE Queensland is at the forefront ofthese initiatives, and attitudes ofresidents in PimpanaCoomera are being explored (see page 53). A number of'eco-villages' are also being built and, in one ofthem, the Curnm1bin Ecovillage which is pictured on our cover, a trial ofurine separation is taking place (see page 66).

Journal of the Australian Water Association

Water

FEBRUARY 2008 l

~ AWA CONTACT DETAILS â&#x20AC;¢ AVS TU IIAM

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'Promoting the sustainable ,I' management o1 water J

POSTAL ADDRESS PO Box 388, ARTARMON NSW 1570

Journal of the Australian Water Association

EMAIL info@awa.asn.au WEBSITE www.awa.asn.au PRESIDENT

ISSN 0310-0367

David Barnes - president@awa.asn .au

CHIEF EXECUTIVE Tom Mollenkopf - cbeer@awa.asn.au

CHIEF OPERATIONS OFFICER Ian Jarman - ijarman@awa.asn.au

EVENTS Linda Kerr-6129495 9914 lkerr@awa.asn.au

MEMBERSHIP INFORMATION AND INQUIRIES Michael Seller - 6 1 2 6581 3483 mseller@awa.asn.au

MEMBERSHIP RENEWALS AND CHANGES Membership Team - 1300 361 426 info@awa.asn.au

MEDIA AND MARKETING Edie Nyers - enyers@awa.asn.au

SCIENTIFIC AND TECHNICAL INFORMATION Diane Wiesner PhD - 61 2 9495 9906 dwiesner@awa .asn.au

WATER EDUCATION NETWORK Corinne Cheeseman - 61 2 9495 9907 ccheesman@awa.osn.au

NATIONAL SPECIALIST NETWORKS Laura Evanson - 61 2 9495 99 17 levanson@awa.asn.au

AWA BRANCHES: AUSTRALIAN CAPITAL TERRITORY and NEW SOUTH WALE S Tanya Webeck - 61 2 9495 9908 actbranch@awa.asn.au, nswbranch@awa. asn.au NORTHERN TERRITORY Hayley Galbraith - 61 2 9495 9919 ntbranch@awa.asn.au SOUTH AUSTRALIA Sarah Ca rey - 61 8 8267 1783 sabranch@awa.asn.au QUEENSLAND Kathy Bourbon - 6 1 7 3397 5644 qldbranch@awa.asn.au TASMAN IA & VICTORIA BRANCH c/o Rachel-ann Martin - 61 3 9235 1416 tasbranch@awa.asn.au vicbranch@awa.asn.au W ESTERN AUSTRALIA Cath Miller - 0416 289 075 wabranch@awa.asn.au INTERNATIONAL WATER ASSOCIATION, AUST. (IWAA) iwabranch@awa.asn.au

DISCLAIMER Australian Water Association assumes no responsibility for opinion or statements of facts expressed by contributors or advertisers.

COPYRIGHT AWA Water Journal is subject to copyright and may not be reproduced in any format without written permission of AWA. To seek perm ission to reproduce Waler Journal material email your request to: enyers@awa .asn.au

2 FEBRUARY 2008

Water

Volume 35 No l February 2008

AWA WATER JOURNAL MISSION STATEMENT 'To provide o print ;ournal that interests and informs on water matters, Australian and international, covering technological, environmental, economic and social aspects, and to provide a repository of useful refereed papers.' PUBLISH DATES Water Journal is published eight times per year: February, Morch, Moy, June, August, September, November and December EDITORIAL BOARD Chairman: FR Bishop BN Anderson, TAnderson, CDiaper, GFinlayson, AGibson, GA Holder, BLobzo, 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: 1. TECHNICAL PAPERS AND FEATURES Bob Swinton, Technical Editor, Water Journal: bswinton@bigpond.net.au AND journal@awa.asn.au 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 4 for more details. 2. OPINION, INDUSTRY NEWS, PROFESSIONAL DEVELOPMENT Edie Nyers, enyers@awa.osn.au Articles of l 000 words or less 3. WATER BUSINESS Brian Raul!, National Sales & Advertising Manager, Hallmark Editions brian.rault@holledit.com.au Water Business updates readers on new products and associated business news within the water sector. ADVERTISING Brian Raul!, National Sales & Advertising Manager, Hallmark Editions Tel: 61 3 8534 5014 (direct), 61 3 8534 5000 (switch), brian.rault@halledit.com.au Advertisements are included as an information service to readers and ore 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 BOX 84, 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

HEALTHY RIVERS HEALTHY PEOPLE By Howard Jones I am a viticulturist with a vineyard within Western M urray I rrigation Ltd on the banks of the mighty Murray in Su nraysia, and like many ochers I rely o n irrigation to produce a crop. Nonetheless, I am very sensitive to the damage that has been done to rhe ecology of rhe river system over my own lifetime, particularly to the wetlands and lagoons. Consequently I was very happy to rake on rhe C hair of the M u rray Wetlands Working Group in 1996. The Grou p arose as a result of meetings between NSW Department of Water and rhe M urray and Lower M urray Catchment Management Committees where rhe idea of a wetland group was moored, to specifi cally focus o n wetland rehabilitation, emphasising the value of healthy waterways and riverine environment along the Murray in NSW and also the Darl ing from Men indee to Wentworth. The Group consists of co mmunity rep resentatives from all walks of life who have a love and respect for healthy wetland systems and good science. In irs deliberations rhe Grou p always uses a "good science" approach ro decide on app ropriate actions. We have undertaken significant data collection relating to rhe thousands o f wetlands connected to the M urray and Lower D arling, and chis data has been adopted by the M D BC. The Group is leading the way in research into rhe causes, impacts and management of' sulfi dic sediments in inland wetland s, ranging from Euston to the South Australian border, linking with rhe M u rray Darli ng Freshwater Research Centre, rhe National Water Comm ission (NWC), the NSW Environmental Trust and the South Australian authorities. Some dozen or more lagoons whose beds have been exposed by historically low water levels, have been identified as having sulfi dic sediments p resent which could potentially develop acidit ies, by oxidation of pyrites, down to a lethal pH 1.8, as observed at Bord e Bend Lagoon in NSW. Some of the targeted actio ns to rehabilitate wetlands have led to water savings, and this has led to contracts with the NSW Government to manage 32 GL o f Adaptive Environmental Water (AEW) within the annual Murray Allocations. The negotiatio ns with government resulted in rhe AEW retaining the original characteristics of use. Thus rhe Grou p can

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Howard Jones is the Chair of the Murray Wetlands Working Group, which was awarded the $100,000 National Thiess Riverprize at the10th International Riversymposium and Environmental Flows Conference, Brisbane, 2007. The Group has developed a number ofgrant schemes to enable individual landowners, community groups and Government agencies to manage and rehabilitate both privately owned and public wetlands and, since 2000, has managed the delivery of75 GL to 200 wetlands, covering 71, 000 ha. either use, or trade in rhe temporary market to the point where the Gro up has recouped in excess of $5M since 2000. T h is maintains the G ro up's activities and provides capital for on-farm projects as well as research into the many impacts facing the river system. An example of th is is the Inland Sulfid ic Sediments project. Jointly fu nded by the Grou p and the NWC ($100,0 00 and $500,0 00 respectively) ir is charged with explo ring management options for such events. One of the great successes o f rhe Group was to provide AEW to individual farmers,

initially within the boundaries of Murray Irrigation Ltd, to water many wetland s on private property. Mainly Black Box and lignum wetlands, they are very productive ecological areas if mai ntained by a healthy watering regime. Murray Irrigation Ltd has jointly p ro moted the project by utilising their irrigation chan nels to d eliver the water. Over 4000 ha have been watered this way during 200 3-200 6. T he program is so popular char other areas are taking part, all chis in the worst d rough t in developed history. The ecological outcomes and the hu man stories are both outstand ing. The challenges of wo rking with river management and werland systems involve borders and jurisdictions, both Seate and local government, bur the Grou p has operated on a "no borders" approach. T he Group has a close working relationship with South Australia and Victoria, with So uth Australia provid ing portable pumping infrastructure and the G roup providing water for wetlands in both Scares. In short, the Group maintains a strong focus o n good science to enable werlands to th rive, with great emphas is o n community involvement. T he strength of the Grou p is its combination of community members and staff. Both sections are experienced operators in many fields of rhe water management, fro m the physical movement of water to the complex ecological makeup o f wetland systems. T he achievemen t of winning rhe Thiess Riverprize provides u nique challenges, firstly to apply rhe generous fu nds to an appropriate target and secondly to choose an in ternational Twin ning Parmer to work with, and if need be, to nurture.

Just add water! A wetland on a property near Deniliquin, November, before a watering pro ject (left] a nd, i n Februa ry, the thriving result (right) . !Photos: Trish Alexander, MWWG's project officer).

Journal of the Australian Water Association

INTERNATIONAL

http://www.abc.nee.au/ news/srories/2008/ 01/15/2139239 .htm

The inaugural Singapore International Water Week will be held from 23 to 27 June 2008. The even t, comprising the Water Leaders Summit, Water Convention and W ater Expo, will culminate in the presentation of the Lee Kuan Yew Water Prize, a prestigious international award to recognise outstanding contributions in solving water issues. http://www.siww.com.sg/

A solution to increased flood risk due co climate chan ge in the Netherlands looks co controlled floodi ng. The government plan ' Room for the river' will see the protective outer dike to the Noordwaard polder lowered by 2m in 2015 to allow the area to flood, easing the pressure on more populated areas and lowering the risk of flooding elsewhere. http://www. rijkswaterstaac. nl

PUB, the national water agency of Singapore, has awarded the contract fo r the fifth and largest NEWater plant at Changi to Sembcorp Utilities (Sembcorp). Sembcorp wo n the bid to design, build, own and operate the plant with a production capacity of 50 ML/day. The plant will be built on the roof-cop of the C hangi Water R eclamation Plant, saving on land and cost of laying pipes. More information http://www.pub.gov.sg/ info_center/ press_release.aspx

Italy's farmers are demanding that the government invest billions of euros in improving water management and erosion control. 7 0% of towns are at high risk of flood s or landslid es and risks are expected to rise as Italy's outdated system of reservoirs and canals comes under increasing pressure from global warming and rapid urbanisation. http://www.enn.com/ top_stories/article/26919

China's government says just under half of its nearly 90,000 DAMS are dangerously unstable and need urgent repair, as it unveiled a th ree-year plan costing 27 billion yuan ($4.17 billion) .

NATIONAL PM Kevin Rudd plans to hold one-on-one talks with each of the State Premiers over the Federal Government's water reform

ASIA-PACIFIC WATER SUMMIT

Arasu Siva rama n o f PUB Si ngapo re w ith To m Molle nkopf o f AWA. The 1st Asia-Pacific Water Summit (APWS) was held in Beppu, Japan o n 3-4 December 2007. AWA C h ief Executive Tom Mollen kopf gave a p resentation at the IWAJWWA International Workshop o n Governance and Regulation in Water Services. Key recommendations from the summit focused on achieving M illen nium D evelopment Goals through

8 FEBRUARY 2008

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water finan cing and capacity d evelopment, d ealing with water related disasters, and water for development and ecosystems.

Presenters a t the 1st Asia-Pac ific Wate r Summ it.

Journal of the Australian Water Association

package. The talks aim to resolve outstanding disagreements, particularly involving the government of Victoria o n the $10 billion Murray-Darling program. http://news .smh.co m.au/pm-co-holdseparate-state-talks-on-water/20071217l hk2.html Several federal workin g groups have been announced by the PM Kevin Rudd at the press conference following COAG. Federal Minister Penny Wong will be the chair of a special worki ng group on climate change and wate r, and South Ausrralia its deputy chair. http://www.p m.gov.au/ news/ interviews/200 7 / interview_000 11.cfm Urban water authorities have faced growing criticism for fai ling co invest in adequate water supplies. H owever, Water Services Association (WSM) estimates that the largest 27 urban water au thorities paid total reported d ivid ends in 2005-06 of $1.104 billion co their state authorities up from $930 million the year before. http://www.wsaa.asn.au http://www.theaustralian. news.com .au/scory/0,,2303953623850,00.html%3Ffrom%3Dpublic_rss Federal Cabinet has approved the establishment o f Infrastructure Australia to be a key driver in the fight against inflation by boosting the eco nomy's productive capacity. The effort will be directed co unclogging roads and pons and fast tracking water and energy focused projects. h ttp ://www.pm.gov.au/ news/ releases/20 08/ media_release_0000 9 .cfm The Australian Government announced plans to establish a $30 million Centre for Groundwater Research and Training co seek solutions to Australia's water scarcity problems. The Centre will be funded join tly by the National Water Commission and the Australian Research Council, which would each provide $15 million over five years to the project. The key objective of the Centre is to b uild capacity in knowledge and skills in a new generation of groundwater scientists in order to improve the way groundwater is managed. http://www.nwc.gov.au /news/ media_ releases/ media_release_l 6nov07 .cfm Australia's two largest cities had contrastin g fortunes when it came to rainfall in 2007. At 1499mm, Sydney had its wettest year since 199 9 and its dams increased from about 36% to 60.1 % http://www.sca.nsw.gov.au On May 15, 2007, Melbourne recorded its driest 36 5 days on record, with just 316.2mm ofrain, less than half its average of 65 2mm. h ttp://www.bom. gov.au

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T he Water Services Association of Australia has released a National Waste Water Source Management Guideline for public comment. The guideline has been in development for the past 2 years and is intended to be a compli mentary document to the Australian Drinking Water and the National Water Recycli ng Guidelines. See hccps://www.wsaa.asn.au/framesec2.html before 20 February 2008. Co mments should be made to granc.leslie@wsaa.asn.au

ACT Minister for che Environment, Water and Climate Change Jon Stanhope an nounced increases to che ACT Govern ment's rainwater tank rebates chat will came into effect on 1 February 2008. The rainwater tank rebates available to ACT residents will increase by $200. The new rebates will range from $750 for a tank of at least 2,000 litres capacity. http://www.chiefminister.acc.gov .au/ media. asp?media=3355&section=24&tirle=Media %20Release&id=24

NSW H ouseholds in Sydney, the Illawarra and Blue Mountains have cut their annual water use by 75,000 litres since 2002-03 with average consumption fo r a single residential dwell ing falling from 297,000 licres per year in 2002-03 before water restrictions were introduced to 222,000 litres in 2006-07. http:/ /www.sydneywacer.com.au/Who We Are/Media Cen ere/ MediaView. cfm?ID =436 Water restrictions on irrigators, graziers and industry have been eased in pares of western New South Wales after much needed Christmas rain. In the Macquarie Valley 100 per cent of water entitlements have been reinstated for towns, high security licence holders and stock and domestic users, and domestic restrictions eased for the Barwon Darling River region. http:/ /www.abc.nec.au/ news/stories/2008/ 01/04/2131574.hcm

QLD Widespread storms and rain across south east and west Q ueensland continued co deliver benefits for rural communities and the environment over the Christmas-New

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Year period, with the state Minister for Natural Resources and Water declaring it a promising scare to the wee season despite the spectre of damaging floods in ocher areas. http://scacemencs.cabinec.qld.gov.au/MMS/ ScacemencDisplaySingle.aspx?id=55847 The Queensland Government has moved to link che Loganholme and Sandgate wastewater treatment plants to Gibson Island Advanced Water Treatment Plant (pare of che Western Corridor Recycled Water Project) to provide a further 44ML of water per day to Wivenhoe Dam. h ccp:// scacemen cs.cabinet.qld.gov.au/MMS/ ScacemencDisplaySi ngle.aspx?id=5 59 53 Groundwater resources of the Coastal Burnett region have been included in the Burnett Basin Water Resource Plan. The plan specifies objectives to protect existing access to groundwater and to protect the Coastal Burnett aquifers from further progression of seawater intrusion. A consultation report is available on the NRW website. lmp://www.nrw.qld.gov.au/wrp/burnett

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However, a conservation group is calling for the release of a Federal Government report it says has information that co uld potentially damage the Queensland Government's attempt to build a dam in the Mary Valley. T he Wide Bay Burnett Conservation Council says the Commonwealth's draft audit should detail the effectiveness of strategies to protect lungfish at Paradise Dam on the Burnett River. http:/ /www.saverhemaryriver. com/downloads/pdfs/U2BrochScreenA4. pdf http:/ /www.coordinatorgeneral.qld.gov .au/ library/ pdf/senate/Doc_ 15_Final_Draft_ Report_NRW_ v2_rev.pdf

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760 ,000 ML of floodwaters from heavy rains in the north have passed down the Queensland's Paroo River system into NSW, refilling parched wetlands along the way including Currawinya National Park's Lake Numalla, a bird breeding ground in SW Queensland, according to the latest statement from Namral Resources and Water M inister, Craig Wallace. h tcp:/ / scaremencs.cabiner.qld.gov.au/MMS /StacementDisplaySingle.aspx?id= 56113 Prolonged rains and floods in Queensland have failed to ease level 6 water RESTRICTIONS because increases in storages in che worst areas of supply have only moved to 27.2% total capacity (buc up from 7.20%). http://www.cheauscralian.news.com.au/ story/0,25197,23094184500 6786,00.hcml http:/ /www.qwc.qld.gov.au/ Warer+use+measuremen c

SA Rebates for audits on domestic water use are now available to help South Australians further reduce water consump tion. T he new Home Water Audit rebate of up to $1 10 allows homeowners to receive reimbursements on low-flow showerheads, wacerwise garden products, dual-flu sh toilets and efficient washing machines. http:/ /www.premier.Sa.gov.au/ news. ph p?id =2621

VIC Melbournians used approximately 69 billion litres less water in 2007 than in 2006 principally through savings, stage 3 and 3a restrictions, amounting to a 16% reduction in water consumption equivalent to adding three full Maroondah Reservoirs to che water supply system. http://rhesource.melbournewater.com.au/ con tent/ media_releases/ media_releases/ 200801 0 7.asp

Journal of the Australian Water Association

Victoria's Planning Minister Justin Madden has announced that the desalination plant near Wonchaggi will be subject co an Environment Effects Statement (EES) with preliminary analysis indicating there is a need for further investigation of potential loss of native vegetation and impacts on landscape, flora, fauna and marine ecology. Derails at http://www.dpcd.vie.gov.au Concerns about potential increases in domestic water prices have been raised about a fa ilure by the Victorian Governmen t to release detailed costing and funding options for the state's controversial new desalinatio n plant. http://www.theage.com.au/ news/ national/ key-calks-held-on-scate-water-supplybut-no-leaks/20 08/0 l /05/ 1198950131214.html http ://www.dse.vic.gov.au/DSE/ nren pl. nsf /LinkView/5249619A2A2 l 3442CA2573B E00 7EEAA992FBC7Cl33A6F520CA257 2DA00 7FAB8B On 20 December 2007, the Minister for the Environment, Heritage and the Am approved an application by the Port of Melbourne Corporation co deepen the mai n sh ipping channels in Port Phillip Bay under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). http:/ /www.environment.gov.au/ ep bc/ notices/assessments/2002/5 76/ approval-decision.pdfThe issue however remains controversial as final approvals are still co be given as at publication date. An outbreak of toxic blue-green algae in the Gippsland Lakes has prompted health authorities to warn people to stay our of the water. The hoc weather has caused an outb reak of algae on Lake Victoria and Lake King. http://www.abc.ner.au/ news/stories/2008/01/04/2131611 .htm In Victoria, the Essential Services Commission's (ESC) final report in to its review of a range of water tariff reforms has been completed with recommendations on pricing structures to deliver on economic efficiency, social equiry and environmental sustainability for the water sector. http://www.dpc.vic.gov.au/domino/Web_ N ores/ newmedia.nsf/8fc6e I 40ef5 583 7 cca 256c8c00 l 83cdc/39d04f2fea3a84b8ca257 3d600735d5a!OpenDocu menc

WA Research by WA's Department of Water confirms that remote communities continue to be at risk from poor qualiry water in soaks & groundwater, where levels of trace metals & elements such as uranium and arsenic exceed safe drinking

water guidelines. Th is has been a looming issue for some years. http: / /www.rheaustralian.news.com.au/ story/0, 25197,23052245-5006789,00.hrml http:// portal. water.wa.gov.au/ portal/page/ portal/WacerManagement/Publicarions/ PublicarionsLisc/Contenc/WQPN%2009% 20Community%20drinking%20wacer%20s ources.pdf

INDUSTRY A recent and thorough review of che guidance on fluoride addition to drinking water, a common practice in Austral ia, has confirmed its value and failed to find any clear link between claimed adverse effects including cancers claimed in some overseas media. http://www.nhmrc.gov.au/ publications/ synopses/eh4 l syn.hrm T ransfield Services Led and Worley Parsons will joinrly work on rwo mobile desalination facilities fo r the Brisbane River, a special $125 million project ai med ar addressing water shortages in south east Queensland. http://www.rransfieldservices.com/T S/LIVE /RESOURCES/DOCUMENTS/2008/ BrisbaneRiverDesalinarionPlancs.pdf The Busi ness/Higher Education Round Table (B-HERT) has named ICE WaRM as winner of its 2007 Award for Outstanding Internacional Collaboration in Education and Training for its groundbreaking profess ional development programme with China's Yellow River Conservancy Commission (YRCC). This program, managed by ICE WaRM, has involved extensive collaboration with its five fo unding partner universities in three stares - led by the University of South Australia, with the University of Adelaide, Deakin University, Flinders University and

Central Queensland University - as well as the water industry and ocher key stakeholders in Australia.

PEOPLE IN THE NEWS LARRY ZIMMERMAN has been appointed Program Management/ Construction Management (PM/CM) Practice Leader for BLACK & VEATCH's global water business. http://www.bv.com ROD LEHMAN, a past AWA President, has resigned from his role at CH2M Hill effective 14 December. In the near term he will be undertaki ng freelance consulting. Contact Lehmannrod@Primusonline.com.au VINCENT CHEAH has joined KBR's Syd ney office as a civil engineer and currenrly joins che Water Delivery Alliance ream at Erskineville vincenr. cheah@kbr.com ALAN WEE recenrly of COM Singapore's mari na barrage project, also joins KBR's Erskineville alliance ream with extensive pipelines and pu mp stations design experience alan. wee@kbr.com MURRAY THOMPSON, Port MacquarieHastings Council Water Supply Manager has taken out the 2007 National Local Government Engineering Medal. Congratulations Murray. KAITLIN LANGDON has won the 2008 Steve Balcombe H obart Water Scholarship, which provides the opportunity to work in rhe water sector while undertaking an undergraduate engineering degree at the University of Tasmania. http: //www.hobarrwater.com.au/ HobartWater/_Documen rs/2007 +Media+ Releases/Sceve+Balcombe+2008+ Scholarship+winner.pdf

GRAHAM DOOLEY, previously MD of Uni ted Utilities Australia has joined Osmoflo as an advisory board m ember. More information luke.ryler@fuller.com.au STUART GLENN, former Managing Director of PB in the Australia- Pacific, has been appointed as Chief Operating Officer of PB In cernational. Derails RRidgway@pb. com.au JIM MANTLE, fo rmerly Director of Operations for PB, Australia-Pacific, has been appointed the new Managing Director, Australia-Pacific. Derails RRidgway@pb.com.au TONY CORBETT formerly of Melbourne Water has joined Connell Wagn er in Brisbane as Systems Planning Lead in the Water and Environment Group. corbenT@conwag.com JOHN MCCALLUM, a Principal and group marker leader with Conne ll Wagner was recenrly appointed Director Water & Environment Business on the fi rm 's Development Board www.conwag.com ROBIN ALLISON, SHAUN LEINSTER and GEO RGIE WETTENHALL have moved from Ecological Engineering to establish a new consultancy called Design Flow all@designflow.ner.au JEFF PARISH from the Central Irrigation Trust was awarded an Order of Australia Medal. The head of the Riverland's largest water crust was honoured for his contribution to the irrigation industry and his efforts in developing and implementing water delivery services and contribution to efficient resource management. Mr Parish has been worki ng in the industry for 42 years. http: //www.abc.net.au/ news/stories/2008/ 01/28/2148057.htm

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Journal of the Australian Water Association

water

FEBRUARY 2008 13

EUREKA PRIZE FOR WATER RESEARCH AND INNOVATION

Professor Shahbaz Khan Recent winner of the 2007 Land and Water Australia Eureka Prize for Water Research and Innovation was the CSIR O and C harles Srurt project ream led by Professor Shahbaz Khan fo r rhe irrigation system now bein g applied across the Murray-Darling Basin. "Imagine bringing together th e hydrology of the padd ock and farm , connecting it to rhe groundwater and surface water flows of rhe regional catchmen t, and then being able to quantify rhe fl ows o f water, salt and nutrient in the whole system ," explained Professor Khan of the team's achievements. "S uch a complex and difficult undertakin g creates an irrigation system that is harmo nised with both the land scape and catchmen t. Ir also brings science and co mmunity together to manage water, productivity and eco system health in very progressive ways ." T he project's o u tpu ts p rovide critical in fo rmation to allow id entification of possible water savings and increased

effi ciency of water management for irrigated agriculture, one of Australia's maj or industry sectors and water users. T he work is the first assessment of its kind fo r any catch ment in Australia, and u tilised rhe combined expertise of the CSIRO, NSW Department o f Primary In dustries and rhe C harles Srurt U niversity in addition to internatio nal inputs through the U nited N atio ns H ydrology fo r rhe Environment, Life and Po licy P rogram. T he research included a full audit of water, nutrient and salt fl ows throughout the Murrumbidgee and Coleambally irrigation catchments. I t also involved the d evelopment of inn ovative tech nology to rapidly detect channel seepage hotspots, and a decision support system linking geographic and econ omic informatio n with water fl ows. The research is part of rhe Water for a H ealthy Co u ntry Flagsh ip , a CS IRO-led research program that aims to increase the benefits Australia gai ns from ir water resou rces. The p roject has m ade an impact abroad, leading to m ulti-level government policy dialogue and changed irrigation water practice in rhe Yellow River Basin , China and the Indus River Basin , in Pakistan. Professor Khan's team is also co ntributing to water management in Pakistan , the Ph ilippin es, C hina, United Kingdom, an d N ew Zealand , while aspects of the work have also been recognised by UNESCO who accredited the M u rrum bidgee as the first global reference catch ment under the H yd rology fo r the Environment, Life and Po licy Program.

NSW EVERY DROP COUNTS BUSINESS PROGRAM AWARDS Five Sydney companies were recognised for achieving significant water savings at th e an nual Sydney Water Every Drop Counts Business

Program Awards. T he awards ceremony, held last November, saw NSW Water Util ities M inister Nathan Rees recognise the organisations and individuals who had made significant reductions in water use and demonstrated commitm ent to water conservat ion. Accord ing to Sydney Water, since its launch in 2001 the p rogram has attracted 375 memb ers at over 1,9 00 sires that are generating savings of ap proxim ately 34.1 m illion litres of water a day, or 12 billion litres a year, enough to supp ly aroun d 51,000 households. This year's award recip ients are:

• Innovation- Am cor Fibre Packaging, Botany

• Largest percentage reduction Stockland fo r its properties at 333 Kent Street, Sydney and 60 1 Pacific H ighway, St Leonards

• Largest percentage Key Performance Indicator reduction Boral T ransport Sydney T ippers

• Largest volume reduction - BHP Billiton for Illawarra Coal in Appin

• Sustainable processes and practices - GPT Group (Office Portfolio) and JLL Asset Managem ent (Asset Managemen t Services).

We all like to be recognized In the water industry, companies are making leaps and bounds to improve sustainability in their operations. Some, however, jump higher than others. For nearly a decade, the Stockholm Industry Water Award has honoured the companies who set the bar on what can be achieved under creative, committed, and caring leadership. Our winners are recognised as the best in the industry with unquestioned dedication building a better world. Does that sound like your company? Apply online for the Stockholm Industry Water Award at www.siwl.ora. The deadline for nominations is February 28, 2008.

INDUSTRY ":::::::=:"'WATER AWARD

14 FEBRUARY 2008

water

Journal of the Australian Water Association

water FUTURE FEATURES MARCH - Energy mini misation , review of Austral i a' s desalinat i on plan ts, membrane technology, fu rther options for water resou rces, Asia -Pacific issues, odour management MAY· SCADA, disi nfection, tren ch less tech nology

JUNE - ENVIRO 2008 report & sel ected paper s, pres su re sewers, disinfectio n, WI CD, education & tr aining

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MEANDER DAM DELIVERS FOR DAIRY FARMERS IN NORTHERN TASMANIA The Meander Dam, located about 80km west of Launceston, is now complete and scoring water in che new lake, H untsman Lake. The dam, with an inundation area of 364 ha, has a gross capacity of 43,000 mega-litres (ML) and an irrigation capacity of 24,000ML. In che 1980s preliminary work o n the Meander Dam started when che site was cleared prior co rhe planned commencement of construction in 1989. A change of government saw che proposal shelved for some time; however in 2001 che Tasmanian government provided $7 million for che project as pare of the Economic Infrastructure Fund. In August 200 1, then p remier, the lace Jim Bacon, released che Water Development Plan for Tasmania, with che Meander Dam identified as its cornerstone The Meander Dam Project is unique in rhac the majority of fu nding will be generated th rough che sale of irrigation rights, commencing at $1,000 ML, and rising co $1, l 00 ML in July 20 07. There has been significant interest in irrigation rights from both local and interstate farmers looking fo r reliable irrigation water, with almost half che available water having being sold.

concrete panels. Roller Compacted Concrete has the same ingredients as conventional concrete, but is much drier with much less cement. The combination of low cement and dryness means ic can be placed quickly and easily with large-volume earth-moving equipment. In che case of the Meander Dam che RCC was transported fro m an onsice batching plane co the dam face via a conveyer belt and chen spread with a wheel loader and pozi-crack. Finally the mix was compacted by vib ratory rollers co a thickness of 300mm per layer as dictated by laser levels.

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The dam wall was co mpleted in November 2007 with the delivery of irrigation water co investor farms in December 2007.

Deadline for submissions is February 29th, 2008. For award categories and further details please visit www.iwahq.org

FEBRUARY 2008

Water

Journal of the Australian Water Association

International Water Association

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How? Thanks to an integrated location intelligence system informing Bill where he needed to be to carry out today's precautionary maintenance.

With ESRI Australia's Geographic Informat ion Systems (GIS) solutions, you too can accurately locate and better manage your company's assets, and plan your day-to day operations in greater detail to prevent any future potential problems that may impact specific properties or services. Not only can you organise and manage location-based information from various sources using GIS, but you can also enable distribution of this information via the web, and out in the field.

From improving the daily demands of routine maintenance, planning for and handling emergency events, to ensuring the future viability of your water network, location intelligence helps you to more effectively manage your water assets. Find out how we can help you benefit from improved incident management, better customer service delivery, and increased operating efficiencies by making your utility truly location intelligent.

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by users sea rching the di rectory's database.

AWA's newly fo rmed T echnical Programs Team wh ich includes: Community Education (WEN) and Awards, Water Induscry Capacity Developmen t (WICD), National Specialise Networks and the newly created Australasian Biosolids Partnership Program. AWA's new organisational structure is provided below to clear up any confusion in the changeover.

The directory aims ro provide a comprehensive catalogue of water related resources and programs that target school students and the community in Australia. Education providers and users can connect with each ocher after searching the Water Education Resources D irectory and then make d irect contact with the resource/program owner. U ltimately chis should increase networking, promote sh aring of leading p ractice education program and resource models, and prevent reinventing the wheel.

Ac the time of writing the Community Education Coordinator position was being recruited and we hope to have the position filled this month. The Community Education Coordinator will coord inate the WEN and its associated activities, including the upcoming Water Education Conference on the Gold Co ast, and will also take on the coordination of AWA's Natio nal Awards Program.

Corinne Cheeseman, National Manager Programs

WATER EDUCATION NETWORK {WEN)

The Water Education Resources Directory is now live and available publicly. Providers, creators and managers of school and commun ity water education programs and resources are encouraged to upload content. There is a simple registration step and once providers have received their username and password they are able co enter details of relevant resources and programs which are uploaded instantly for p ublic view. The Water Ed ucation Resources w ill on ly be as good as the content it contains so please ensure that your organisations education and communicat ions team is aware of it and d irect chem to register at: h ttp://resources.awa.asn.au/apply.php to upload resources and programs to make this valuable tool a success!

Water Education Resources Directory

A partnership pro;ect funded by A WA and the NSW Government Water for Life Program

water educ:atlon ne twort:

As you may be aware, AWA advertised the role of Community Education Coordinator in December and January. This position will replace my exist ing role as Educat ion Manager as I take on a newly created role in AWA, Nat ional Manager - Programs. In my new role, I will be leading program development fo r AWA's major con ferences (ENVIRO and Ozwater) and managing

A Water Education Resources Directory has been develo ped in partnership wit h the NSW Government Water fo r Life P rogram. Thi s national o nline di rectory, which focuses on school and commu n ity education, provides a space for providers and developers of education resources and programs (related to water) to list and categorise them so th at they can b e found

CHIEF EXECUTIVE Tom Mollenkopf

EA TO CHIEF EXECUTIVE C~re Beer

TECHNICAL & POLICY

Diane Wiesner

NATIONALMANAGER, PROGRAMS

CHIEF OPERATIONS OFFICER Ian Jarman

Corinne Cheeseman

IT MANAGER

POLICY OFFICER

Terrv Loos

NATIONAL SPECIALIST NETWORKS COORDINATOR

MartlnBjofke

FINANCE& COMPANY SECRETARY

EVENTS

CHIEF FINANCIAL OFFICER Rupa Bala

NATIONAL MANAGER, EVENTS

I PRINCIPAL SCIENTIST

I I MEMBERSHIP & AOMIN I I BRANCH SERVICES I

IT&COMMS

I Edie Nyers

NATIONALMANAGER, MEMBERSHIP Michael Seller

WEB CONTENT MANAGER

DATABASE ADMINISTRATOR

Scott Powell

Vlyada Gow

COMMUNICATIONS MANAGER

Wayne Castle

GENERALACCOUNTS Domenic.a Uardo

SENIOR EVENTS MANAGER Unda Kerr

laura Evanson

COMMUNITY EDUCATION COORDINATOR

EVENTS MANAGER

ACCOUNTS

Hayley Galbraith

Pam Bjorke

TBA

BRANCH & EVENT

MEMBERSHIP SERVICES ASSISTANT

I WATER INDUSTRY CAPACITY DEVELOPMENT COORDINATOR

Emma Dibben

Stephanle seddon

RECEPTION & OFFICE

ADMINISTRATION

AUSTRALIASIAN BIOSOUDS PARTNERSHIP COORDINATOR

Denise Whtte

I 18 FEBRUARY 2008

water

NSW/ACT BRANCH MANAGER Tanya Webeck

SA BRANCH MANAGER

QLD BRANCH MANAGER

Kathy Bourbon

Journal of the Australian Water Association

TBA

~rah Carey

VIC/TAS BRANCH MANAGER Rachel~ann Martin

WA BRANCH MANAGER Cath Miller

3rd Water Education Conference Water Efficiency 08 1st Water Industry Capacity Development Conference

If you are involved in water education , communications, water efficiency, water conservation, industry training and professional developmen t or H R then make sure you are at The Gold Coast International Hotel from 31 March - 2 April 2008 . The Water Education Conference, Efficiency 08 and the Water Industry Capacity D evelopment Conference are being run concurrently with combined functions and exhibitions. D elegates attending one of these conferences may cross over streams at no additional cost. Registration and programs are now available at www.awa.asn.au /events T hank you to our valued conference sponsors.

Conference Dinner Sponsor • MWH

3rd Water Education Conference • Gold Coast Water (Platinum)

Water Efficiency 08 • Field Force (Platinum) • MWH (Gold) • Department of the Environment and Water Resources Australian Government (Silver) • Smart Approved WaterMark (Bronze)

1st Water Industry Capacity Development Conference • C hifley Business School (Gold) • Queensland Government (Silver)

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In 2007, WICD Subscribers identified " national water industry b randing" as one of their h ighest priorities. Since then, WI CD's National Water Industry Employment Branding project team, led by Peter Mills (Sydney Water), have been working closely with Adcorp to create the H 2Oz brand for promoting "Careers in Water" and attracting people into the water industry. To date there has been strong support for the H2Oz concept. To view the Adcorp H 2 Oz creative go to http://www.wicd.org.au/documents/H2Oz_ C reative. pdf In the November WICD Steering Committee meeting, Grant Leslie (WSAA) presented some p reliminary resulcs from stagel of WSAA's Skills Shortage in the U rban Water Industry project, highlighting some sobering numbers, particularly in terms of staff turnover, that water utilities will be grappling with over the next 5 - 10 years. These figures reinforce the need to move quickly, ro attract people into the water industry as the competition for skilled staff is set to increase in the future. T he WICD Steering Committee agreed that the best way to progress this initiative is in several stages:

3rd National Water Education Conference

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FEBRUARY 2008

Water

Journal of the Australian Water Association

1. Purchase the brand identity, promotional materials and website mock-u p from Adcorp.

2. Engage a contractor to develop a submission to the Natio nal Water Commission for fu nding support for the full website and media rollo uc of the brand. 3. Develop H20z Careers in Water into an ongoing, self-funded initiative, possibly based on che highly successful S mare Approved Watermark model.

The project is seeking contributions to the cune of $65,000 to complete the first cwo stages as soon as possible. Sydney Water has already contributed $20,00 0 cowards che purchase of che H20z Careers in Water brand. Contributions from all sectors with in

AWA MASTER CLASSES 2008 The 2007 AWA Master C lasses were hugely successful, with marvellous support from our speakers and great sponsors: Allen Arthur Robinson (Evaluat ing Water Recycling Projects), GH D and Arup (DBOOT Intensive in Sydney and Adelaide) and Clayton Utz (Wacer Infrastructu re). O ur aim is to offer members equally attractive technical and management focused classes in 2008.

MWH Global who will cover practical and application-related issues and D r Tony Fane, Director of the Membrane Research Centre in Singapore provid ing theoretical input.

First off the blocks will be a Master Class on Pre-Treatment fo r Water Treatment, Reclamation & Reuse, emphasising low pressure membranes and water rather than high pressure RO, sales (as well as sodium chloride), and characterisation ofNOM and other perpetually troublesome foulants. T h is Master C lass will be held in Sydney from 23-24 July 2008 (subject to confirmation). Invited speakers for this class will include Dr Samer Ad ham from

T he second Master C lass in mid August will be Post-Kyoto Regulatory Issues for Water Business. W ith a management rather than a tech nical focus, this class will be limited co 20 members. Again the restriction o n numbers is to faci litate a workshop environment with group work and d iscussion.

che water industry are greatly encouraged as

of all. Please contact Stephanie Seddon on (02) 9495 99 18 or sseddon@awa.asn.au if

the H20z Careers in Water brand is aimed at increasi ng the pool of skilled staff with in the water industry nationally for the benefit

This Master Classes will be limited to 40 members, so as to give attendees sufficient time to ask q uestions and for the speakers to mount a d iscussion over selected key topics.

More information can be found on the Events section (National) ofthe A WA website http://www.awa.asn.au/events

you'd like to d iscuss contributing to chis important initiative.

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Water Journal of the Australian Water Association

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with the exception of Tasmania which is currently served by the Victorian YWP Committee. Each Committee is represented on the YWP National Representative Committee, which C h ris will continue to be strongly involved in as Past President. I would like ro thank Chris for all his hard work.

YOUNG WATER PROFESSIONALS

Erin Cini, National President, AWA Young Water Professionals You may notice a d ifferent photo accompanying this section of the Water J ournal. My name is Erin C ini and it is my pleasure and honour to be taking over from Chris Corr as the National President of the AWA Young Water Professionals. Chris was our first National President and over the last three years was integral in establishing the YWP Specialist Network nationally and increasing the profile of YWPs in the water industry. We now boast seven YWP Committees, one associated with each State and Territory A WA branch,

I now lead your YWP National Representative Committee and also represent Queensland. Other members of the committee are Amanda Kobes (Vice President; WA) Chris Corr (Past President: VIC); Victoria Leavold (VIC); Lee-Anne Carmody (NSW); Sarah Jewell (SA); Nie M organ (NT), Zoe Moore (ACT ) and Michael Storey (IWA). Michael is also the Chair of the IWA YWP Committee which adds an international dimension to our NRC. In addition , we are grateful to have the support of Laura Evanson (AWA National Specialist Network Coordinator), as well as three AWA Board Members (Christobel Ferguson, Paul Freeman and Trevor W inton) who generously give their time to attend YWP NRC meetings and provide us with invaluable input. The NRC aims to provide direction and support to the YWP Committees, each of which has a team of young professionals

water industry capacity development

WICD 2008 Ist Water Industry Capacity Deve lopment Conference

Water and Skills Shortage - Double Trouble The WICD lnltladwl was Implemented In 2006 and alms to provide greater nadonal coordination of and acc:ess to Wl1IINWIUld training and professional development c:oul'IIII and resoun:es to the lndunry.

WICD Includes nlnln& and professional development of people workin& In the water ti-om Y0Cltlonal to tertiary education u well u human resources upecu relevant to the Industry nadonally.

sector

In 2008,AWA wlD host a nadonalWICD conflnnce to meet the specific: needs of the deleptm In 11*8 profeulonal areu.

Sponsonhlp and exhibition opportunities are available Visit the conference website for program and further Information

Earlybird registration closes 29 February 2008 30 March - 2 April 2008

Enquiries

Gold Coast International Hotel

Phone:

(02) 94 13 1288

Surfers Paradise, Queensland

Fax:

(02) 94 13 I047

AUSTRALIA

Email:

wicd08@awa.asn.au

www.awa.asn.au/events/wicd08 24 FEBRUARY 2008

Water

Journal of the Australian Water Association

who engage local young water professionals and provide networking events and inspiring professional development activities, including technical forums, networking events, soft skills workshops, trivia nights, weekend trips, and conference workshops. All of these are great events not only for YWPs to attend but all AWA members, as participants gain much more out of an event with a cross section of generations and careers experience. We have a number of obj ectives for 2008, based on rhe 2007-2008 Business Plan which has been discussed on this page previously. Please check this section in the coming months for information on the roll out of a number ofYWP programs including mentoring, increasing the participation of student members, engaging non-engineering and science YWPs, capacity build ing, and strengthening our strategic alliances with like-minded organisations. More information on the Business Plan is available on rhe YWP section of the AWA website - www.awa.asn.au/ywp An example of such an alliance is the 2nd Australian Young Water Professionals Conference (Brisbane, 4 - 6 February) which was jointly organised by the AWA and I nternational Water Association. By the rime this is in print, rhe Conference will be over and I am sure has been a huge success expect to read all about ir in the March Water Journal and the next edition of the YWP Newsletter. Over the last two years I have been fortunate to have been a member of both the NSW and QLD YWP Committees. When I moved to Queensland as part of my role as an engineer with KBR, I turned up in a new state where I knew very few people and went to a QLD YWP Committee meeting. I found an energetic group of people who, although perhaps not necessarily similar in personality or interests, welcomed me and assisted in making my transition easier. Of course I reluctantly left behind an equally talented and fr iendly bunch in NSW; which seems to be a fairly consistent trait with the YWPs that I have had the privilege of meeting through my involvement in various events and committees. I look forwa rd ro meeting more of you and getting to know you through my role as National President. If you are not already involved I encourage you to consider getting in touch with your local YWP Committee and joining the Committee or participating in one of our upcoming events. You can find out more abour YWPs and upcoming events in your state or territory on the AWA website www.awa.asn.au/ywp

NEW MEMBERS AWA welcomes che following new members since the mosc cecent issue of Water fottrnnl:

H2 Options Australia Pty Ltd

IMCD Australia Limited

PO Box 254

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Water

Journal of the Australian Water Association

• Automation • Data Logging • Pressure Control • PH / ORP • Flow Meters • Plastic Piping Systems • Automated Meter Reading Equipment • Under Pressure Tapping Equipment

URBAN METABOLISM IMPROVING THE SUSTAINABILITY OF URBAN WATER SYSTEMS F Pamminger, S Kenway Sustainability has been a powerful concept shaping businesses and policy over the last decade. Some have chosen this aspirational path to be leaders and others see it as necessary for survival. Either way the concept has been adopted as it is perceived to add value by helping find solutions which improve environmental, social and economic conditions. For all the perceived value chat the concept of sustainability delivers, there will come a rime when it will either evolve into something else or be replaced. This article has been written to present a hypothesis of what rhat change might be. W e present this for those wanting to be at the vanguard of thinking to deliver business improvements. To hypothesise what that change might be, lee us first consider how the sustainability concept as typically used in the water sector could be improved. Curren rly, the relative contribution to sustainability of different optio ns primarily considers separate analyses of environmental, social and economic indicators. These results are then "traded-off' against each other using weighting criteria and value judgement. We believe that it is too si mplistic to reduce the concept of sustainability to its constituent parts. For example, if our task is to manage water resources, and we need to determine the quantity of water a city requires at a given time, traditionally we would have presented the result as o ne unique solution. In a world where there is little external variability or interconnectivity with ocher processes, people, or other elements in the environment, this co uld fu lfil the task. However, we have learnt this is no longer the case when we plan for water services. Supply-demand forecasts made for the next 50 years can be our-of-date within months of a study being completed. For example if new knowledge around climate change emerges. Energy or greenhouse intensive water supply solutions can be considered to add to uncertainty because of the additional impacts they may contribute to global warming. Consequently they exacerbate (even if only as a small percentage) the

28 FEBRUARY 2008 Water

..., \){"'80

a) Present

Imported w ater Rainwater Energy

,,,,.,,,,

Water Syst

8tJ,

.,.,- -

~~~

----row" Inputs

,.---,

LJvobHlty ond

' ___ ..... ' .-- - - - . . , ,

t:::),

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-.. . . . . . . , '- IIYOM-belng

Wastewater Stormwater Blosollds Greenhouse gas General waste s

Recycling

~~:ria ls

+ Efficiency

, '

,,,~

-----

/ 0 ~0 ,;

..._ :_rrr,ation & KnÂ°"" -

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----- .... '

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Inputs

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~:~:~i~ts Food

C)~ n

\ ,

, l'Jforrnation & KnovJ\e~; / -

I 1 /

mll:mCil~ Outputs

kX Efficiency / Recycling

...._ ._ -

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W astewater Stormwater 1

~ ~:o~~:use g;;1s General waMes

Figure 1. Metabolism of the " urban water system " a nd a sustainable future direction. water shortage problem they are trying to avert if proposed in isolation (i.e . without reducing emissions elsewhere) . We believe that the reductionist paradigms so commonly used in our society today are both lim iting us finding alternative solutions to today's problems and contributing co the downward trend of global ecosystem health (refer Millennium Ecosystem Assessment). The limitatio n exists because our management, reporting and the majority of o ur science and pu blication effort is focussed on components as opposed to whole systems. This largely reflects how we have historically allocated responsibilities for constructing and maintaining infrastructure. Conducting a sustainability analysis using a reductionist paradigm makes it very difficult to know if our actions contribute to the long-term health of the system o f which we are a part. This system could be at global, city or local scales. Some may argue that the use a of a Triple Bottom Line framework aims to circu mvent

New ways of thinking.

Journal af the Australian Water Association

such an outcome. H owever, these approaches arguably rely more on anthropogen ic value based judgements than o n science. Weighting variables d oes not advance the analysis. We would argue chat a Triple Bottom Line analysis is a pragmatic p rocess to reach a solution. However, it may not necessarily deliver a more sustainable solution. Let us propose another concep t chat we believe can advance the sustainability of urban water solutions. T o achieve this we need to begin thinking holistically about how nature works. T his is a degree more complex than usual as we need to think of all the interconnections. From this perspective, the processes that bind all th ings together are the flows of energy, water, air and food. These elements are needed to survive and grow. Essentially they are nature's currency. Nothing lives fo rever, and some species depend on the death of others for their survival. Seasonal variability is also evident and in some cases necessary fo r survival. Over billions of years organisms and ecosystems have evolved to use these resources p rimarily at high levels of efficiency. In many instances the most

tecnn1ca1 Teatures

resilient designs have survived and science is now uncovering elements of systems design which lead co consistent races of natural resources utilisation per unit of body mass from uni-cellular bacteria right through co the largest organisms such as whales. Looking at our own human body, Tambo (2002) presents another example of a very efficient system chat is pertinen t co the issues facing the water industry at the moment. 'The water inside the human body transports substances and heat, and is disposed o f from che body afrer it has been recycled and re-used about twenty times. This m eans that about 5 per cent of the amount of water inside the body must be replenished with fresh water supplied from outside the body.' Analysing nature from this perspective is achieved by thinking of the metabolism of a system. Urban metabolism is a systems way of looking at the resource inputs and waste outputs of groups. An urban metabolic analysis relies o n measuring the overall water, energy, materials and wastes moving into, out of (and ultimately scored within) a city. This mass-balance of a city "enti ty'' was first proposed by Abel Wolman in I 965 as a means of addressing evident "shortages of water and pollution of water and air". The movement of water, energy and m aterials ch rough cities are all increasingly measured, modelled and importantly verifiable using mass-balance principles. A schematic representatio n of an urban metabolism model is shown in Figure 1. Sustainable directions can be quantified using metabolic analysis by accepting or assuming chat the mass flow of energy, water and materials through a city need co reduce over time - even if the population increases. There are curren tly two principal ways of achieving chis: increased recycling or increased efficiencies. However if technology enabled complete recycling at minimal energy (or CO2 expense) efficiency would be less important. A fundamental challenge for the engineering of future cities and their water systems is co reduce metabolic throughput while improving

liveability and overall ecosystem well-being. The internal layers of our cities such as che infrastructure, economic and governance systems all influence how effectively these materials are used now and how easily our future systems will transition co more sustainable forms. Now let us present how using urban metabolism chinking could potentially refine our urban water services. Knowing the metabolic race of a city helps co understand che relative co ntribution chat a particular policy or sector can make co reducing the metabolic race. For example the water sector could aim co reduce urban dependence on the environment through the provision of water su pply and waste management services through recycling of wastewater or scormwacer or through improving efficiencies. In doing so the metabolism model gives a very tangible and practical way of id entifying co ntributions as organisations or individuals co reducing the metabolic race. Jc also high lights areas chat need the greatest attention or which could most cost-effectively reduce metabolic rate. By creating a co nsistent 'system boundary' for metabolic analysis, a frame of reference will also be created against wh ich the lifecycle of compo nents such as water system s can be viewed. Sustainable cities will require reduci ng our urban metabolism but we also need co recognise this cannot be done by planning for one 'organ' at a rime. For example the water sector is inextricably connected co the energy sector which is connected co p opulation and so on. Using the urban metabol ism m odel, we see the delivery of water as interconnected with greenhouse gas and nutrient emissions. Future city planners and infrastructure designers will not only consider potable water, sewerage and scormwater systems as one but will also consider water, energy and nutrient flows together rather than separately in their outlook plans. In doing chis, systems would be designed with flexibil ity for change rather than as a static independent element. Ultimately our cities and their water systems will be monitored and

benchmarked for their "metabolic efficiency" and their relative draw from and impact on local and global environments. Annual reports will record such m etrics together with the relative contribution chat a particular sector makes co che overall reduction of the coral metabolism of the city. Smart meters may well become fu ndamental measurement cools making transparent water, energy and nutrients flows co operators and co the market place. As we move forward with global carbontrading and local energy and nutrient trading schemes, metabolic analysis will inform the "race of exchange" between these parameters which are necessary fo r che life and future of our cities. In so-doing our systems will make better use of nacural capital, as suggested by Paul Hawken, Amory Lovins and Hunter Lovins in their b ook, Natural Capitalism, and drive systems to configuratio ns better suited and tailored co their local environment. In summary, sustainability wi ll continue co be a very useful concept co advance water services. Leaders in industry will however find new ways of chinki ng that wi ll add to this model and help chem use it in more practical ways and consequently add value co businesses. We believe chat urban metabolism is a key perspective and valueadding way of thinking that can be applied broadly within the water industry.

Acknowledgments The authors acknowledge the support of their respective organisations, Yarra Valley Water and CSIRO (Water For a Healthy Country Program). Help ful review comments from Allen Kearns and Tim Baynes are also acknowledged.

The Authors Francis Pamminger is che Manager of Research and Innovation at Yarra Valley Water, Melbourne, email: francis.pamminger@yvw.com.au; Steven Kenway is a Research Scientist w ith CSIRO Land & Water, Brisbane, email: Steven.Kenway@csiro.au

Journal of the Australian Water Association

water

FEBRUARY 2008 29

technical features .fereed paper

VIRUS REDUCTION BY CHLORINATION FOR CLASS A RECYCLED WATER G Haylock Abstract

Table 1. Treatment Plant Stages Microbiological Red uctions.

T he Epsom Spring Gully Water Recycling Project provides Class A recycled water for agriculture, irrigation of parks and gardens and miscellaneous industrial uses. A sevenlog10 reduction of viruses needs to be achieved by the treatment plant. A free chlorination process was designed to p rovide a four-log 10 reduction o f viruses. MS2 bacteriophage was selected as the challenge o rganism, and hepatitis A selected as rhe target organism. Samples of spiked tertiary effluent were disinfected by a free chlorine residual. A Cr of l 0 mg.min/L was required to achieve a fourlog10 reduction of MS2 in tertiary effluent at pH 8 and 2O°C. Use of literature values for the disinfection of MS2 and hepatitis A in buffered laboratory water were used to predict the pH and temperature dependence and extrapolate to rhe requ irement for hepatitis A inactivatio n. A Ct of 18.4 mg.min/L was derived for a fo u r-log inactivation of Hepatitis A, in this BNR, tertiary filtered effluent, for a pH range o f 6-9 and minimum temperature of 10°C.

Introduction The Epsom Spring Gully Recycled Water Plant is designed to produce C lass A recycled water for agriculture, irrigation of parks and sporrsgrounds and miscellaneous industrial uses. The plant supplies water to an area in and around the City of Greater Bendigo, Victoria, Australia. The project is further described by Fasham and Watson (2007) . The effluent for the recycled water p lant is sourced from the Bendigo Water Reclamation Plant (WRP) . The plant is a Modified University of Capetown Biological Nutrient Removal (BNR) process. The plant processes include:

Process

BNR treatment plant Primary ultraviolet disinfection Chlorination Secondary ultraviolet disinfection Total

• Primary alum dosing; • Maturation Lagoons; 30 FEBRUARY 2008

Water

Protozoan {109 10)

3.4 (2.2) 0.3 4.0

1.6 (0.6) 3.0

0.7 8.4 (7.2)

3.0 7.6 (6.6)

Figures based on median removals. Values in parenthesis are 5th percentile limits • Secondary alum dosing; • D eep bed dual med ia filte rs; and • Ultraviolet (UV) disinfection. The Epsom Sp ring Gully Water Recycling Plant includes the fo llowing process steps to produce Victorian EPA Class A recycled water: • Low Lift Pumping Statio n • C hlorination using free chlorine; • Ultraviolet disinfection. • Dechlorination using sodium metabisulfite; and • High Lift Pumping Statio n There is a second stage, curren tly under construction, to provide a parallel stream of ultrafiltration, followed by reverse osmosis and electrodialysis reversal process, to reduce the TDS of the fi nal effluent. Treated mine water, from Bendigo Mining Limited mine dewatering operations, is combi ned with the above Class A streams, just upstream of the High Lift Pumping Statio n, to produce "fit fo r purpose" water for reuse purposes. The Victorian EPA require the following effluent microbiological quality standards for Class A water (EPA Vic, 2005):

• E.coli - < 10 org/1OO ml-median • Virus - 7 log 10 reduction from raw sewage to treatment process outlet -

• Inlet works; • BNR plant (Modified University of Capetown process);

Virus (log1ol

Determining Ct values for free chlorination of viruses in BNR ejjluent.

Journal of the Australian Water Association

median, 6 log 10 reduction from raw sewage to treatment process outlet - 95th percentile • Protozoa - 6 log 10 reduction from raw sewage to treatment process outlet median, 5 log 10 reduction from raw sewage to treatment process outlet - 95 th percentile • Helminths - specified detention or filtration process (essentially 4 log 1o reduction) The microbiological removal performance of the treatment pro cess m ust be verified by the Victorian Department of Human Services (DHS). Helmi nth removal must meet rhe regulatory requirements of the Chief Veterinary Officer of Victoria. The combined treatment processes provide the microbiological removal performance detailed in Table 1. The removals through the BNR and tertiary fi lters are based upon 8 months of monitoring of autochthonous microbiological indicators through the WRP treatment process.

Chlorination of Viruses Chlori nation was chosen as the major process for virus inactivation, because it is more cost effective than UV disinfection. It also generates significantly lower amounts of greenhouse gases in its production than the electricity consumption of the equivalent UV disinfection process for C lass A reuse. Whilst it is used as the major virus inactivation pro cess, it is important to have multiple barriers. Combining d isinfection processes is complementary, so

mrefereed paper

recycling char if one process is not so effective agai nst one type of virus (e.g. adenovirus resistance co UV disinfection) it will be better inactivated by rhe other processes (e.g. ch lorine). T he cho ice of chlorine species is nor straightforward. A free chlorine residual requires a low ammonia concentratio n co reduce chlorine demand. A 1 mg/L co ncentration of ammo nia-N will consume approximately 10 mg/L of chlorine co pass the breakpoint and display a free chlorine residual (White, 1999). A free chlorine residual is, however, not as stable as a chloramine residual. However ch loramination requires, a small amount of ammonia in the effiuent as a minimum, which may require add ition of ammonia during summer. Monochloramine versus free chlori ne formation may also swing wildly if diurnal variations exist in treatment plant effl uent ammonia. Free chlorine was chosen over chloraminarion, because of the significantly lower Ct (Cr= chlorine co ncentration (mg/L) x contact ri me (mi n)) required for free chlorine versus chloramination. For example USEPA (1999a) requires a Cr = 6 mg.min/L fo r fo ur log 1o virus inactivation. Conversely chloramination requires Cr= 149 1 mg.min/L for fo ur log 10 virus inactivation (USEPA, 1999a). T his means free chlorination requires a smaller contact rank and/or a lower chlorin e res idual.

3. Monovalent metal salts, such as sodium and potassium, added to laboratory pH buffer solutions significantly increase virus inactivation, particularly at higher pH values (Sharp, 1980 and Berg, 1990). Measurable differences in inactivation have been observed between distilled water, surface or drinking water and laboratory solutions (Berg, 1989). 4. Particle attached and aggregated (as opposed co dispersed) virons show increased resistance to disinfection. The inactivation versus Cr curve will display shouldering or railing, depending upon rhe relative fractions of dispersed and aggregated virons Qensen et al., 1980, Berg et al., 1990 and Sobsey et al., 199 1). 5. Different viruses and different virus strains have differing inactivation responses to disinfectants such as free chlorine (Payment et a!., 1985), or was this due to particle association and aggregation differences between strains? It was considered that the effects of attachment to and shielding of viruses by particulate matter, ion effects and effects of organic nitrogen would mean char using

data from laboratory stud ies wo uld underestimate rhe required Ct for Bendigo WRP treated wastewater. Testing was th us undertaken on rhe effluent itself to investigate the stability of free c hlori ne residuals and the required Cr val ues for inactivation of viruses. l r was decided to use MS2 bacteriophage as the challenge organism, because it is non-pathogenic, readily cultu red, stable and readily assayed. The literature studies undertaken in phosphate buffered, chlorine-demand-free water would be used to adj ust the MS2 results to dete rmine the Cr required for disinfection of h epatitis A. This virus was chosen, in conjunction with OHS, as the target organism.

Experimental MS2 (ATCC 15597-Bl2) was prepared by incubating Salmonella typhimurium WG49 (ATCC 700730) with MS2 coliphage at 37Â°C in rryprone yeast extract-glucose broth (TYG B). T he culture was stored overn ight at 4Â°C in contact with ch lo rofo rm, followed by centrifugation to produce a phage suspension of approximately 10 10 pfu/mL. The TYGB

There is no literature readily ava ilable on the quantitative inactivation of viruses by free chlorine in well-nirrified treated wastewater effluents. W hilst there is some lirerarure available on chlorination of viruses in drinking water (USEPA, 1999a and USEPA, 19996) and buffered laboratory water (Sobsey et al., 1988 and Grabow eta!. 1983), these are not necessarily applicable co all wastewater effl uents (Metcalf & Eddy, 2003). A literature search identified a moderate number of studies on the inactivation of viruses by free chlorine in buffered laboratory water. The majority of studies have been carried our using strains of poliovirus. The fo llowing effects were identified from these studies: 1. pH affects inactivation of viruses by chlorine. Higher pH values, particularly above 9, make viruses significantly more resistant to inactivation. This is partly due co the hypochlorous acid/hypochlorire ion acid-base equilibria (Sobsey, 1989 and Englebrecht et al., 1980) . 2. Increasing temperature increases virus inactivation for the same Cr (USEPA, 19996).

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Journal of the Australian Water Association

Water

FEBRUARY 2008 31

exhib ited a signifi cant chlorine demand and so the M S2 was concentrated by two success ive centrifugation steps wi th polyethylene glycol (PEG6000) and then resuspended in phosphate-buffered salin e so lution. T he seed was transferred overnight, ch illed (at O to 4°C) , to Ecowise Environmental laboratory, Bendigo. Samples of fresh, tertiary filtered, UV disin fected, effl uen t were collected from Bendigo WRP and transfer red to the Ecowise laboratory, Bendigo. Six samples were taken , between lace O ctober and early D ecember 200 6. Ten litre samp les were dosed with 10 10 - 10 14 pfu ofMS2, which had been prepared approximately three days prior (except for the first trial, wh ere there was o ne week delay between preparation and use) . O nce the Bendigo efflu ent was dosed with the bacteriophage, the solution was stirred gently (G ~20 s· 1) fo r 30 minutes, to allow the phage to attach to any suspend ed solids presen t. Sod ium hypoch lorice solu tion was dosed to achieve a free chlorin e residual of 3 -6 mg/L. The required do se was p re-determ ined , by cescs with effl uent and a DPD chlo rine test kit. The sample was mixed rapid ly after chlorine addi tion, fo llowed by slow agitation (G ~ 20 s· 1), to sim ulate conditions in the chlorine contact tank. The effluent pH was not corrected fo llowing sodium hypochlori ce additio n, so as to mimic behaviour in the full- scale system. Pairs of aliquots of the chlorinated virus mixture were taken at set rime intervals. One aliquot was immediately titrated fo r chlorine resid ual species using the DPD-FAS titration method , based on APHA 4500-C l F (APH A, 1998). T he ocher aliquot was quenched with sodium thiosulfate and transported chilled by overnight co urier to the Ecowise laboratory, M elb ourne, fo r MS2 bacteriophage assay. Samples were assayed by the double layer method (H avelaar and Hogeboom, 1984) on plates p repared with nalidixic acid and Salmonella typhimurium W G 49 bacteria, with and without RNase.

Results

Parameter

Median

Maximum

< 0.1

0. 3

0.3 0.0 1 56.2 63. l

1.6 0.05 61.7 64.6 33

10 0.39

30 7.7 7.9 17.6

pH before chlorination

66.1 72.4 35 10 8.2 8.1 22.3

8 8.0

< 2

pH alter chlorination Temperature (0 C)

8.0 19.8

Table 3. Bendigo W RP tertia ry effluent quality recorded duri ng the trials. 5th Percentile

Parameter

BOD5 (mg/ L) Suspended solids (mg/L) Turbidity (NTU) UV transmittance before chlorination 1%)

0.4 59 25 455 120

Apparent Colour before chlorination (CU) TDS (mg/ L)* Sodium (mg/L)* Potassium (mg/L)*

Median

95th Percentile

4 1 0.5

5 2 0. 8 66 30 730 180 38

63 28 480 140 24

* Measured during July to Septem ber 2006

Table 4. Chlorine dosed and free chlorine residua ls. Run Date

Chlorine Dose [mg/ L]

Immediate Free Chlorine Residual [mg/ L]

Free Chlorine Residual after 30 mins [mg/ L]

18.4 9.0 6.75 7.5

8.8 5.2 4.7 4.9

7.3 8.0

5.5 Not available

4.3 2.6 1.6 1.8 2.0 3.6

26-10-2006 9-11-2006 16-1 1-2006 23-1 1-2006 30-11-2006 7-1 2-2006

10.0 9.0

8.0

..J

s.ii

7.0

II "\.'\ 5.0

Water

Minimum

Ammonia-N (mg/L) Organic-N (mg/ L) Nitrite-N (mg/L) UV transmittance before chlorination (% cm-1) UV transmittance alter chlori nation (% cm-1) Apparent Colour before chlorination (CU) Apparent Colour alter chlorination (CU)

·;;;

The Bendigo WRP effl uent quality is d etailed in T ables 2 and 3 . The ammonia was generally low and th us did not cause sign ificant demands on chlorine. UV transmittance and colour was measu red fo r pre and post chlorinatio n effluents. There was an average 24 colour units red uction and 6.4 percentage point increase in UV transmittance due to the free chlorine residual. T h is verified the in crease in UV d isinfection efficiency, and supported an early design decision to locate the secondary

32 FEBRUARY 2008

Table 2. Quality of Bendigo WRP sampled effl uent.

0,: QI

6.0

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4.0

3.0

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2.0

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0.0 10

.,_.

1.0

- -26-Oct-06 - - -9-Nov-06 -+- 16-Nov-06 - - 23-Nov-06 ~ '30-Nov-06' -+- 7-Dec-06

Tlme(mln)

Figure 1. Traces of Free Chlorine Residuals with Ti me.

Journal of the Australian Water Association

- ,, 50

,!,

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UV disinfection downstream of free chlorination.

6 ~ - -30 Noverrber 2006

oNCl3

The doses of chlorine and resulting immediate and 30 min free chlorine residuals are presented in Table 4. The free chlorine decay wirh time fo r the six ru ns is plotted in Figure 1. The free chlorine residual decay with time was observed to be divided in to three phases:

(mg/L)

;j' •

oDi chloramine (mg/L)

•Mono chloramine

g '

(.)

• an immediate chlorine demand exerted by the tertiary effluent. Its presence could only be detected as the difference between chlorine dosed and the immediate free chlorine residual. It is likely that this is due co reactions with organic substances and nitrogen species.

(mg/L) 1J Free Cl2 (mg/L) 10

Typical chlorine res idual fractions and their change with time are prese nted in Figu re 2. Inactivation of MS2 phage with Cc is plotted in Figure 3. The Cc, at each cimestep, was calculated by essentially linearly interpolating the residual with rime and then integrating chis C vs t trace with respect to time. The runs all show taili ng in disinfection effectiveness with ti me. T ai ling is hypothesised to be due to virus attachment to and shielding by suspended soli ds and virus aggregation. Aggregation is known to increase with the age of che MS2 suspensions. T he humps in the disinfection curves, approximately midway are unexplained. It was clear that four to six and possibly eight log 10 reduction of MS2 could readily be achieved with free chlorine in chis tertiary effluent.

The first data point, in Figure 3, fo r each curve is shown ac time c = 0 min. le is, however, likely chat chis free chlo ri ne residual and che co rresponding MS2 inactivation rep resent the scare at 1 to 2 minutes. T his is because there is a delay in adding che chlorine solution, mixing and then caking aliquots for chlorine res idual and MS2 analysis. A different experimental setup would be required to determine che disinfection performance during chis shore period. le is evident from Figure 2 chat significant disinfect ion is occurring during ch is period, due to the higher free chlorine residual at this rime. T he experimental setup however mimics che fu ll-scale setup, as che sodium hypochlorice is dosed in che contact tank inlet pipe, where it undergoes rapid mixing, and then the inlet free chlorine residual is measured in che contact tank inlet. Rapid virus inactivation is expected to occur during chis period. The worse-case Cc required for four-logio inactivation of MS2 in Bendigo tertiary wastewater effluent was 10 mg.min/L, at about pH 8.0 and temperature 20°C. This Cc was determined by linearly interpolati ng

. - t -~ 60

-2.00

::~!~'~rom mit.altest ten-peratures to 20 deg C

-4.00

!!!

r===:::-=i

-6.00

:::::,:~w;::::::::::--=it~- - - ·~~- --l..1 -+- 16 No11-06

> 0

E -8.00

~ _3"' -10.00

-12.00

"°*"" 23-No-,.06 ~ 30-No-,.06 -+- 7-Dec-06

---- -+

-14.00 CT Free (mg.min/L)

Figure 3. Laboratory MS2 Inactivation with respect to Ct.

34 FEBRUARY 2008 Water

Time (min)

Discussion

Alternatively, ch lori ne decay may be fitted by an exponential (first order) decay model. The linear fie however seemed to better fie the data points.

..-~ ..

Figure 2. Typical Chlorine Resid ual Fractions and their change with ti me.

• a slower, apparently linear, decay over the remainder of the test period.

Time (min)

• a rapid, but detectable, almost linear, decay over 5-10 mi n.

0.00

16 Noverrber 2006

Journal of the Austra lian Water Association

between the firs t two disinfection po ints of the data series for each cesc dare. T he laboratory rests were carried out at approximately pH 8 and temperatures of 17.6 co 22.3°C. The data was corrected co 20°C, before plotting in Figure 3.

le is necessary co extrapolate the data co che target organism hepatitis A and adjust for the expected range of pH and temperature. The results of laboratory trials, from che literature in phosphate buffered chlorine demand free water for both MS2 and hepatitis A were used for chis purpose. T he fo llowing fo rmula was used co extrapolate the Bendigo experimental Cc:

C.t HAV. Bendigo. pH x , operlemp _ C.! HAV,lab,pH x , closes1/ab1emp

C.t MS2.lab , pH 8. closest !ab temp X C.f MS2 , Bendigo, pH 8,test temp

X C .tVir11s ,USEPA,pH 6- 9, oper1emp C .t Virus ,USEPA , pH 6-9, tesi temp

References for MS2 and hepatitis A inactivation at 5°C (Sobsey et al., 1988) and ac 25°C (Grabow et al., 1983) and for the influence of temperature (USEPA, 19996) were used for chis purpose. The results are plotted in Figure 4.

le can be seen chat MS2 is the more resistant virus at pH 7.0 to 9.2. Beyond pH 9.2 both viruses require increased Cc values; presumably because of the higher pH favouring che existence less potent hypochlorice ion instead of che hypochlorous acid molecule. Using che Rothberg, Tamborini and Wi nsor water quality model V3.0, it was predicted char pH values in che chlorinated effluent would not exceed 8.6. To be conservative, a maximum pH of 9.0 and minimum pH of 6.0 was adopted for

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design. Historical data indicated the minimum effluent temperature is l0°C. A Ct= 9.2 mg.min/L was adopted, for hepatitis A over the pH range of 6.0 to 9.0 and temperature l 0°C. Whi lst there has been work on inactivation of a number of v iruses, most of the science is underpinned by work on poliovirus . Sobsey et al. (1991) states chat hepatitis A was adopted as the target organism, because of its severity, its substantial excretion by infected individuals, its stability in faeces, water and wastewater and evid ence of it being a cause of waterborne disease. T here is still a shortfall of work on the inactivation rates of more resistant and prevalent viruses such as Norovirus (Keswick et al., 1985). Aggregated Coxsackie BS virus is more resistant than hepatitis A, but it has not been possible to work with non-aggregated suspensions. These viruses are difficult to assay. Due to the prevalence and expected resistance o f Noroviruses, it is recommended that further research is undertaken into its inactivation by chlorine species. Keswick et al. (1 985) indicates the four-log 10 Cc of particle attached (veal infu sion broth suspension) Norovirus is of the order of 250 mg.min/ L, in free chlorine , at pH 7.4 and temperature 25°C. A safety factor needs to be added to the C t fo r the following reasons (in order of magnitude): • differences in the extent of particle association between MS2 and hepatitis A and other potential target viruses; • d ifferences in aggregation of M S2 and hepatitis A in Bendigo WRP tertiary effluent; • differences in the relative responses of hepatitis A and MS2, between buffered water and wastewater salinities; • changes in effl uent q uality not detected during the seven weeks of trials may impact on chlorine species, nitrogen species and suspended solids present; • rhe rapid demand at O to 2 minutes would affect the true shape of the inactivation vs Cr plots. The issue of dispersed and aggregated viruses needs to be considered and an appropriate allowance should be made for fil tered tertiary wastewater effluents. Our experiments used dispersed MS2 viruses, as chloroform was used for separation of the viruses from the culture. Extrapolation to hepatitis A was carried ouc using d ispersed virus tests (Sobsey et al. ,1 988). Also particle association in trials and tertiary effluent would be an issue. Sobsey et al. (1991 ) found that cell associated hepatitis A virus required 13.5 times the free chlorine C t to that required

FEBRUARY 2008

Water

35.0

~--------- -~------- _,__,_+1------+-Sobsey HAV 5C

------ sobsey HAV 10C Grabow H,O.: 25C

- . .SobseyMS2 SC - - sobseyMS2 10C

10.0

_... Grabow MS 25C

5.0

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

Figure 4. Extrapolation of Bendigo Ct values for MS2 and Hepatitis A Virus as a Function of Temperoture and pH, for a Four Log Reduction of HAV and MS2. for dispersed viruses, fo r four- log 1o inactivation at pH 8 and 5°C. Hejkal et al. (1 981) found char indigenous enterovirus in undisinfecred created wastewater was 3.4% particle associated virus and the rest particle free. Average virus aggregates in both free and particle associated fractions consisted of an average of only 3 to 4 virons. Wellings et al. (1976) found indigenous viruses in undisinfected effluents from a major wastewater treatment plant, were 17% particle associated at 0.08 mm filter size. Assuming free virus aggregates of 3 virons and applying multihir kinetics, adds a factor of (4+log 10 3)/4. This equates to a mulriplier of 1.12 times. As a conservative assumption based on H ej kal eta/. (1981), assu me 10% of hepatitis A is particle associated. Adopting a C t multiplier factor of 30, for particle associated hepatitis A, as a conservative multiplier based on Sobsey et al. (1991 ), then the reduction in kill for a fou r-log virus reduction, due to particle associatio n, is 4 log/(4log x 90 % + 4log/30 x 10%), which equals a multiplier of 1.1 1 times . T he combined multiplier for the two issues is 1.24 times. It is probable chat the M S2 was particle associated in the trials (Templeton et al. 200 5), thus incorporation of the particle associatio n factor may already be included. An overall multiplier of 2.0 was applied co the derived hepatitis A Ct (9.2 mg.min/ L, for a pH range of 6.0 to 9.0, at 10°C). This provides a conservative safety factor which incorporates all the mechanisms above. Presently we are not allowing for inactivation ofNorovirus, as the required C t in wastewater effluents is un known. T he proposed conservative Cc of 18.4 mg.min/ Lis 3.1 times higher than suggested drinking water Cc values (USEPA

Journal of the Australian Water Association

1999a and USEPA 19996) . The C c was calculated by integrating the free chlorine residual with respect to time. Further work is required to determine whether Ct values need to be based on other emerging pathogens, such as the abundant Human caliciviruses (Huffman 2003), instead of hepatitis A. Factors also need confi rming to allow for particle associatio n and aggregation of target viruses in wastewater efflu ents, instead of extrapolating figures for enteroviruses.

It needs to be noted that any further studies need to differentiate between effluents with measureable concentrations of ammonia, which chloraminate, compared with low ammonia effluents, which produce a measureable free chlorine residual. T reared wastewater effluents are also characterised as having moderate concentrations o f sodium and potassium, compared with lower concentrations in drinking water and d istilled water and high concentrations o f these cations in b uffered laboratory studies. Buffered water studies underestimate the required Ct for drinking water and wastewater effluents. Therefore they should not be used on their own for determining drinking water and wastewater disinfection Ct values.

Conclusions T his paper demonstrates a determination of required Ct values, for reuse applications, for free chlorination of viruses in a tertiary filtered BN R effluent. The required conservative Ct for four-log 10 reduction of viruses is thus 18.4 mg.min/L, at pH 6.0-9.0 and minimum temperature of 10°C. These Ct values are based upon integrating the free chlorine residual with respect to time.

Even in a BNR and dual media filtered effl uent, the Cr fo r virus inactivation by free chlorine is 3 rimes char required for similar inactivation in drinking water. Effluent quality factors alone require a 1.5 rimes higher Cr for Bendigo effluent over drinking water or USEPA values, without any safety facto rs. Safety factors were included to allow fo r particle associated viruses and effluent quality variation. Ir is expected that fil tered acrivared sludge (nonBNR) effluents may require higher Cr values again, due to lower sludge ages, the greater concentrations of organic nitrogen and particulate matter. Comparable membrane-filtered effluents would require lower Cr values, due to lower numbers of appropriately sized particles.

Acknowledgments Beca appreciates rhe assistance of: • Coliban Water for fu nding; • Ecowise Environmental for carrying our the experimental work; • Ian Law (IBL Solutions) fo r inputs into rhe experimental method; • Campaspe Asset Management Services in providing sampling and operational assistance for this study; and • rhe Victorian Department of Human Services fo r their com ments.

The Author

Grant Haylock is Senior Wasrewarer Engineer, Beca Pry Ltd, Level 4, 5 Q ueens Road, Melbourne 3004, granr.haylock@beca.com

References APHA (1998), "Standard Methods for the Examination of Water and Wastewater", 20t h Ed . Berg, G., H. Sanjaghsaz and S. Wangwongwatana, (1989), "Potentiation of the Viricidal Effectiveness of Free Chlorine by Substances in Drinking Water", Appl Env Micro, 55, 2, pp 390-393. Berg, G., H. Sanjaghsaz and S. Wangwongwatana, (1990), "KCl Potentiation of the Viricidal Effectiveness of Free Chlorine at pH 9.0", App Env Micro, 56, 6, pp 1571- 1575. Englebrecht R. S., M. J. Weber, B. L. Salter and C. A. Schmidt, (1980), "Comparative Inactivation of Viruses by C hlorine", App Env Micro, 40, 2, pp 249-256. EPA Victoria (2005), "Guidelines for Environmental Management - Dual Pipe Water Recycling Schemes - H ealth and Environmental Risk Management", Pub No. 1015, p 16- 17 . Fasham P. and A. Warson (2007), "Epsom Spring Gully Recycled Water Project: Which is More Precious - Gold or Water>", Proc Ozwater 2007, Australian Water Association.

Grabow W.O. K., V. Gauss-Muller, O.W. Prozesky and F. Dienhardt (1983), "Inactivation of Hepatitis A Virus and Indicator Organisms in Water by Free C hlorine Residuals", App Env Micro, 46, 3, pp 619-624. Havelaar, A. H . and W . M H ogeboom, (1984), "A method for the Enumeration of malespecific bacreriophages in Sewage",]. Appl. Bacterial., 56, 3, pp 439-447. Hejkal, T.W., F.M.Wellings, A.L. Lewis and P.A. LaRock, (1981), "Distribution of Viruses Associated with Particles in Wastewater", Appl Env Micro, 41, 3, pp 628634 Huffman D.E.,K.L. Nelson and J. B.Rose (2003), "Calicivirus-An Emerging Contaminant in Water: Stare of the Arr", Eviron. Eng Sci; 20, 5, pp 503-515. Jensen H ., K. Thomas and D. G. Sharp, (1980) "Inactivation of Coxsackieviruses B3 and B5 in Water by Chlorine", App Env Micro, 40, 3, pp 633-640. Keswick B. H ., T.K. Satterwhite, P.C Johnson, H.L. DuPont, S.L. Secor, J. A. Bitsura, G.W. Gary and J .C. Hoff, (1985), "Inactivation of Norwalk Virus in Drinking Water by Chlorine", App Env Micro, 50, 2, pp 261264. Metcalf & Eddy, (2003), "Wastewater Engineering, T rearment and Reuse", Fourth Edition, McGraw Hill, p 1243. Payment P., M. Tremblay and M. Trudel, (1985) "Relative Resisrance to Chlorine of Poliovirus and Coxsackievirus Isolates from Environ mental Sources and Drinking Water", App Env Micro, 49, 4, pp 981-983. Sharp D. G., D.C. Young, R. Floyd and J. D. Johnson, (1980), "Effect oflonic Environment on the Inactivation of Poliovirus in Water by Chlorine", App Env Micro, 39, 3, pp 530-534 . Sobsey M .D., T . Fuji and P.A. Shields (1988), "Inactivation of H epatitis A Virus and Model Viruses in Water by Free Chlorine and Monochloramine", Wat Sci Tech, 20, l 1/ I 2, pp 385-391. Sobsey M.D. (1989), "Inactivation of HealthRelated Microorganisms in Water by Disinfection Processes", Wat Sci Tech, 21 , 3, pp 179-195 . Sobsey M. D ., T. Fuji and M. Hall, (1991), "Inactivation of Cell-Associated and D ispersed H epatitis Virus in Water'', J AWWA, November 1991, pp 64-67. Templeton M.R.. R.C. Andrews, R. Hoffman (2005), "Inactivation of particle associated viral surrogates by Ultraviolet Light", Wat Res, 39, pp 3487-3500. USEPA (1999a), "Alternative D isinfectants and Oxidants Guidance Manual", Pub No. 8l5R-99-014, pp 2-26, 2-35 to 2-37. USEPA ( 1999b), "Disinfection Profiling and Benchmarking Guidance Manual", Pub No. 815-R-99-013, table 3.5, p 3.20. Wellings F.M., A.L.Lewis and CW.Mountain, (1976), "Demonst ration of Solids-Associated Virus in Wastewater and Sludge", Appl Env Micro, 31, 3, pp 354-358. White G. C. (1999) "Handbook of Chlorination and Alternative Disinfectants", 4th Edn, Wiley-Interscience, p 430-432.

.fereed paper

OPPORTUNISTIC PATHOGENS IN DRINKING AND RECYCLED WATER DISTRIBUTION SYSTEMS M V Storey, C E Kaucner, M L Angles, J R Blackbeard, N J Ashbolt Abstract T he spatial and temporal (seasonal) distribution of microb ial pathogens and indicators in seven m unicipal dri nking and six recycled water systems across a range of cl imatic zones in Australia was investigated. Members of the major opportunistic bacterial pathogenic genera aeromonads, legionellae, mycobacceria and pseudomonads were recovered from distribution systems by standard culture and molecular methods, with Naegleria fowleri and Type 1 Legionella pneumophila detected in some system s though only in the absence of a measurable d isinfectant residual. There was no di rect relationship observed between the concentration of nutrients and the number of culcurable heterotrophs, though given the m u ltitude of facto rs contributing to microbial regrowth in d istribution systems it was d ifficult co resolve cause and effect relationships. Nonetheless, cemperacure, hydraulic demand and disinfectant appear to be the most important factors influencing the incidence of opportun istic pathogens at the study sites and should remain the focus of furthe r attention . T he outcomes of chis study will assist the development of management protocols for opportunistic pathogens within d istribution systems and aid the ongoing refinement of local and international drinking and recycled water guidelines.

Introduction Depending on the characteristics of treatment and distribution, drin king water supplies may contain a wide range of m icroorgan isms . The vast majority of these do not pose a source of public health concern. A potential exception though lies with a group of naturally occurring organisms termed the opportunistic pathogens (Ashbolt, 2003; Szewzyk et al., 2000; Ford, 1999). Opportunistic pathogens, which include members of the aeromonads, legionellae, mycobacteria and pseudomonads, have been implicated in a

FEBRUARY 2008

Water

range of commun ity and hospital-acquired infections, and as their name suggests, can cause d isease in individuals with a compromised (primary or secondary) defence system . Primary defence mechan isms of the human body include the skin, which can be breached through burns, cuts and abrasions. Secon dary defences, including the body's imm une system, are generally compromised in the very elderly and young, through immu nosuppressive medication, HIV infection and chemotherapy. By definition, approximately 20% o f the pop ulation of an in dustrialised nation (such as Australia) is classified as immunocompromised (Gerba et al., 1996). Notwithstanding this statistic, opportunist ic pathogens are fou nd commonly in the natural environment though infection is relatively rare in the general community. Outb reaks and clusters of disease chat do cake place generally occur as a result of m an -m ade devices su ch as cooling cowers, humidifiers and endoscopes, where conditions for both the p ropagation and delivery of these organ isms is optimal. Using the legionellae as an example, clinical illness is reported in th e order of one infection per 100,000 persons per annum (Fields et al., 20 02). Based on serop revalence data and the under-reported and under-d iagnosed nature of legionellosis (Legionnaire's disease) though, chis figure is estimated co be at least ten times h igher. For the remainder of the opportunistic pathogens, most of which do not cause reportable disease, minimal surveillance data exists on their incidence and likelihood of infection in the community. There is anecdotal bel ief that given their nutrient-rich status, recycled water systems may provide an environmen t that promotes

It is important to adopt a pragmatic approach to their incidence within a distribution system.

Journal of the Australian Water Association

the growth of the opportunistic pathogens. Furthermore, water is often d istrib uted over long distances at elevated temperatures in Australia, providing conditions chat are favourab le for th e regrowth of microbial indicators and pathogens.

Ir is generally considered that reticulated water should be m aintained at temperacures less than 20Â°c (or greater th an 60Â°C) co inhib it the proliferation of organisms of human health concern such as the legionellae (Emmerson, 2001). In the majority of cases, though , chis is not achievable and Australia's water u tilities therefore m anage m icrobial regrowth through chlorination in accordance with local drinking and recycled water guidelines. This Cooperative Research Centre (CRC) for Water Quality and T reatment project demonstrates a fu rther seep in risk identificatio n and management in drinking and recycled water treatm ent and d istrib ution, and is currently supported by eight of Australia's major water utilities. Each of the opportunistic pathogens investigated in ch is study is described in the Australian Drinki ng Water Guidelines (NHMRC/ARMCANZ, 2004) though co date there are no health-based targets for these organisms in drinking and recycled waters in local or international guidelines.

Materials and Methods The incidence of the major opportunistic pathogen groups and faecal indicators was examined in seven drinking and six recycled water distribution systems around Australia. To account for seasonal variability, samples were taken during a w inter Oune-August 2005) and summer study Oanuary-March 2006). Sampling sires included the Rouse Hill Development Area, NSW as well as recycled water schemes in Canberra, Melbourne, Darwin, Adelaide and Broome. (Figure 1). With the exception of the Rouse Hill dual reticulation system, where water is designated fo r indirect h uman contact th rough to ilet fl ushing and garden use, the

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WJ08

refereed paper

recycled water sch em es reused water for the irrigation of landscape and recreational grounds. Though recycled water schemes provided the major focus of this study, for each recycled water system investigated, an adjacent drinking water system was studied as a co ntrol. A drin king water system in M arvel Loch, Western Australia, was also chosen to investigate microbial regrowth issues associated with the 600 km long Kalgoorlie Pipel ine. Drinking and recycled water distribution pipes were exhum ed at locatio ns rep resen ting d iffere nt res idence times within each d istribution system. P ipes were excised at proxim al, m edial and d istal sites from the point of distribution and biofil m recovered from pipe surfaces by scrapi ng . Biofilms and water sam ples were then individually assayed fo r the p resence of opportunistic pathogens by standard culture-based methods as well as by direct molecular detect ion using polym erase chain reaction (PCR). T he incidence of classical enteric pathogens such as Campylobacter and Helicobacter spp. and traditional microbial indicators E. coli, total coliform bacteria, en terococci, as well as Clostridium perfringens spores, F-RNA and somatic bacteriophages was sought using standard culture techniques. Organisms within the genera Aeromonas, Burkholderia, Legionella and Pseudomonas were also screened by cu lture and PC R; and the free-living pathogenic amoeba, Naegleria fowleri by culture. P hysical and chemical water quality parameters were system atically collected to assess their impact on pathogen incidence and regrowth in each water d istrib ution system. T his info rmation included the level of water treatment, age and condition of the distribution system, piping material, quantity and size distribution of particles, disin fectant type and concen tration , pH, conductivity, temperature and hydraulic demand. In addition, total nitrogen, phosphorus and total organic carbon (TOC) contents were measured.

Results and Discussion Results of analysis of water sam ples taken for two months prior to the excavation of pipes and sampling of biofi lms are summarised in T able 1. Briefly, reticulated water temperatures in temperate climates in sou thern and so uth-eastern regions of Australia ranged from a mean daily value of 12°C during winter to between 20 and 26°C during the summer months. At the top en d of Australia in D arwin and Broome the mean reticulated water temperature was 28°C during the d ry

40 FEBRUARY 2008

Water

Sampling Site

Location

Recycled Water Treatment

Application

North Canberra Effluent Reuse Scheme

ACT

Tertiary (incl. microfiltration)

Landscape irrigation and municipal use

Rouse Hill Development Area

NSW

Tertiary (including sand filtration , UV)

Dual reticulation, toilet flushing, irrigation

Eastern Treatment Plant

Vic.

Secondary

Landscape irrigation and municipal use

Bolivar Sewage Treatment Plant

Tertiary (incl. DAFF)

On-site STP

Marvel Loch

Broome recycled water scheme

Secondary

Landscape irrigation and municipal use

Darwin recycled water scheme

Tertiary (inc l. microfiltration)t

Landscape irrigation and municipal use

t samples token prior to microf;ltration p/1nt

Figure 1. Recycl ed water distribution systems investigated duri ng the study . (Drinking water samples were taken from adjacent system s).

Table 1. Average water quality parameters. Samples were taken at 3 locations along each distribution system (n = 8). Data was collected for 2 months prior to sampling in summer 2006.

Site

Unit

Temp (winter) Temp (summer) pH !potable) pH (recycled) Tot. Cl (pot.) Tot. Cl pH (rec.) Free Cl (pot.) Free Cl (rec.) TOC (pot.) TOC (rec.) HPC HPC

oc oc mg/l mg/l mg/l mg/l mg/l mg/ l du/ml du/ml

4. SA

7. NT

6.7

6 .8

7.1

7.5

2. NSW

3. Vic.

7.3

8.1

7.2

8.1

7.7

7. 3

0.9

0.8

0.05

0 .4

0.9

0.3

0.8

0.3

0.02

0.2

0.1

1. 1

0.4 3. ]A

0.4 N/A 0.3 N/A

2 .6

6 .5A

23. l

242

5000

21000

5600

1.3

3.6

1.8

AMeasured as dissolved organic carbon /DOC) N/AData not available.

Journal of the Australian Water Association

6. WA

5.WA

1. ACT

0.7

0.4

1.3

0 .1

0.7

0.3

0.9

0.08

0.7

2.8

30.2

18500

74500

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season (sampled July-August) increasing to 32°C during the wet season (sampled January-February). During rhe summer months pH was in the range of6.7 to 8.1 and 7.1 to 8.1 in drinking and recycled waters respectively, each withi n current national water guideline values (6.5 to 8.5). Total organic carbon (or its dissolved fraction) ranged between 0.7 and 3.6 mg/L in drinking water systems, increasing tenfold in recycled water systems, respectively. Recycled waters were comparatively higher in concentrations of carbon, phosphorous and nitrogen, w hich may explain in part the greater amount of biofilm biomass observed in these systems. A mitigation strategy for bacterial regrowth therefore could be to limit the amount of nutrients that enter a distribution system. Ir is unknown, however, wh ich nutrients should be limited and to what degree. W ith the exception of nitrogen and phosphorus, which were strongly correlated to one another, none of the other water quality parameters (temperature, TOC) or the total number of hererorrophs bore a statistical relat ionship to each other. This finding highlights the o ften anomalous growth of hererotrophs and furth er questions their significance within a distributio n system (Bamam et al., 200 3). With the odd exception, hererorroph numbers increased significantly over rhe length of each d istribution system; chis phenomenon being more p ronounced within recycled systems, with rwo to four orders of magnitude more bacteria cultured at distant sires with in the distribution system when compared to chose in close proximity to the treatment plant. There was generally a one to two log increase in hererorroph numbers over rhe length of a drinking water distribution system. In each case these observations were coupled with a concomitan t decrease in chlorine residual. To determine the significance of pathogen incidence a quantitative risk model was evaluated using the results obtained in this study. Such models have historically been hindered by a paucity of informatio n on the incidence of opportunistic pathogens, but more importantly on the absence of reliable exposure assessment and dose-response data (Rusin et al., 1997). Given che unsuitability of chis model, the outcomes of the project will therefore ad opt a risk-based approach, such as chat being adopted by most water utilities. Rather than focusing on numerically d riven compliance and maximum contaminant levels, the risk approach shifts the focus of performance assessment towards operational and process-driven evaluation of water

42 FEBRUARY 2008

water

Table 2. Incidence of opportunistic pathogens in drinking (potable - Pot) and recycled (Rec) water distribution system biofilms. Samples taken during th e a) w inter Uune August 2005) and b) summer Uanuary- March 2006) months. l. North Canberra Effluent Reuse Scheme, ACT; 2. Rouse Hill Development Area, NSW; 3. Eastern Treatment Plant, Vic.; 4. Bolivar STP, South Australia; 5. Marvel Loch drinking water system, WA; 6. Broome Recycled Water Scheme, WA; and 7. Darwin Recycled Water Scheme, NT. Results are expressed as colony forming units (cfu) in biofilms per square centimetre of pipe surface. In addition to each recycled water scheme, a n adjacent drinking water system was investigated. Winter

1.ACT

2. NSW

Rec

Collfonns

E.coli Enterococci

t t

Somatic phage

F-RNA phage

Aeromonads P se udom onas

t t

Leglonellae

t t t t t t

Burtc.holderta

Rec

Pot

Rec

Campylobact•r

Clostrldia Not sa mpled

Not detected

Rec

Pot

t t t

6. WA

5. WA

4.SA

3. Vic.

Pot

Rec

7. NT Pot

t t t

t t t t

t t

Rec

t t t

< 100 cfu/c m 2

Rec

> 1000 cfu/cm '

< 1000 cfu /cm2

Summer

1. ACT Pot

Rec

2. NSW Pot

Rec

3. Vic. Rec

Pot

5.WA

4.SA Pot

Rec

Pot

6.WA Pot

t t t

Collform1

E. coll Enterococcl

t t t t

Som atic phage F-RN A phage

I-

Aeromonads

Pseudomonas Leglonellao

Burkholdoria

Rec

Campylobactor Clostrfdia

Not sampled

Not detected

In 2004 the National H ealth and Medical Research Council (NHMRC) of Australia, in conjunction with the CRC for Water Quality and Treatment, fo rmulated the Framework for Management of Drinking Water Quality. The Framework now underpins local and international water q uality guidelines for drinking, recycled and recreational waters.

Journal of the Australian Water Association

7. NT Pot

·-

Rec

,._I

t t

< 100 cfu/cm 2

supplies (operator train ing, operational practices and best management approaches). The most effective means of consisrencly ensuring the safety of drinking and recycled water distribution is through the use of a comprehensive risk framework chat encompasses all steps in water supply from catch ment to tap.

The Framework encapsulates a multibarrier approach to managing water quality and related health risks and provides confidence to regulators, consumers and utilities chat risks are being managed

Rec

< 1000 cfulcm 2

> 1000 cfu/cm2

proactively and systematically and corrective actions in the case of noncompliance are undertaken efficiently. Australian water utilities typically manage chlorine levels in their supplies to meet Australian Drinking Water G uideline values, and in che case of water designated for indirect human contact via dual reticulation, Sydney Water manages chlorine levels and other disinfection in its Rouse Hill recycled water scheme in accordance with the NSW Guidelines for Urban and Residential Use of Reclaimed Water (1993). Faecal indicator organisms were not detected at any rime with in d rinking and cerciary-rreared recycled water schemes in the Rouse Hill Development Area and North Canberra Effluent Reuse Scheme over rhe course of the experimental period (Table 2). Members of the aeromonads were detected in low numbers and only at

the extremity of the recycled water distributio n system in Rouse Hill. Legio nellae detected in the Can berra system were found to be not of human health significance. Accordi ng to the ADWG aeromonads have been isolated from several drin king waters in Australia but the relationsh ip between the isolates and clinical disease is not clear.

reduction and recycled water was designated for urban (non-potable) use with restricted p ub lic access, generally recreational irrigation, and in the case of rhe Bolivar STP, on-site reuse. Each system mer current local recycled water guideline values for chemical and microbiological parameters (e.g. < 1000 E. coli per I 00 mL}.

F-RNA bacreriophages being absent from biofilms in both systems despite the presence ocher m icrobial indicators suggesting faecal contam ination (T able 2). Whilst these increased temperatures may play a d eleterious role through the growth of opportunistic pathogens and poss ible regrowth of faecal indicator bacteria, they may have a positive side-effect through the inactivation of enteric pathogens that ca n only grow within warm-blooded hosts (i.e. human enreric vi ruses and parasitic protozoa}.

Aeromonads were detected by standard culture in 9% of sam p les taken fro m drinking water systems (n = I 32) and 49% of samp les from recycled water distributio n systems (n = 114) around Australia. Pseudomonads were derecced in low numbers in d rinking and recycled water d istribu tion systems in Ro use Hill, and like aeromonads were commonly d etected in both types of water in the other study locations. W h ilst there were rwo to th ree orders of magnitude greater culturable bacteria in both Rouse Hill and Canberra recycled water system s com pared to their drinking water counterpart, this did nor translate directly into increased numbers or occurren ce of pathogens .

I n gen eral there were significan tly greater n u mbers of opportun istic pathogens in these recycled water systems when co mpared to tertiary-created systems, though this was expected given their respective level of treatment. There was, however, no direct linear relationship observed between rhe concentrat ion of nutrients and rhe n umber of culrurable heterorrophs in systems examined. Burkholderia pseudomallei were nor detected in biofilms or water in any of the systems examined and furth er analysis of the adjacent soil failed to recover the o rgan ism. Ocher members of the Burkholderia including the opporcunisric B. cepacia were detected in water and soils in endem ic regions.

from biofilms in Darwin and Broome, though it should be app reciated chat Pseudo monads occur common ly in Australian drinking water sup plies and h ave on ly been implicated in illness acquired from health-spa whirlpools. Mycobacceria were detected by PC R in 12% of dri n king (n = 33) and 70% of recycled (n = 26) water distribution systems. The speciacio n and human health significance of these organisms is the su bject of current investigations.

Four secondary-created recycled water system s were examined in the study. Treatment included minor pathogen

The warmer climates in D arwi n and Broome p romoted the inactivatio n of som e of rhe faeca l indicators, with so matic and

The ecology of the M ycobacceria is poorly und erstood and at present there is only circumstantial evidence of a causal

Pseudomonas aeruginosa were recovered

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Journal of the Australian Water Association

water

FEBRUARY 2008 43

relationship between the occurrence of these organisms in water and human disease. According to the ADWG, due to che low infeccivicy of environmental mycobacceria, standards and educatio n programs are not warranted. Little is known of che virulence of opportunistic pathogens and their human health significance within any water distribution system. Opportunistic pathogens are fo u nd almost ubiquirously in the environment, though chis very rarely translates in to incidents or clusters of disease. One notable exception was the outbreak of Aeromonas hydrophila infection char occurred amongst footballers in Western Australia following a game on an oval chat h ad been irrigated by co ntaminated river water (Vally et al., 2004). Ocher notable exceptions generally occur as a result of man-made devices such as cooling rowers, humidifiers and endoscopes; auxiliary devices chat provide conditions for both the propagation and delivery of these pathogens (Szewzyk et al. , 2000). On only one occasion in Australia has an incident of disease been directly attributed to microbial regrowth in a water distribution system per se, though it should be appreciated chat chis was in a remote community, in an uncreated water d istributio n system and in the absence of d isinfection residual (Inglis et al., 2000). Even then the exact causal pathway of chis illness remains the subject of open debate. Human pathogens L. pneumophila (Type 1) and Naegleria fowleri were detected within che drinking water distribution system in the Darwin metropolitan area. The incidence of these organisms in a potable water distribution system would o rdinarily raise concern, and an immediate d isinfection and flushing strategy was initiated by the local utility. le was noted chat both were detected in chis study in a dead leg of the system and in the absence of chlorine residual. This finding, as well as their absence from ocher sampling sires within che Darwin (and Broome) drinking water distribution

Jvvw Hytran WATER HAMMER SIMULATION SOFTWARE

44 FEBRUARY 2008

water

systems highlights the importance of maintaining d isinfectant residual in a distribution system as well as an adequate hydraul ic demand, particularly in warmer climates where elevated reticulated water temperatures (i.e. 28Â°C - 32Â°C) may provide an additional source of heal ch concern. A combined chlori ne concentration exceeding 0.2 mg/L has been shown to eradicate Legionella pneumophila from biofilms formed in experimental systems elsewhere (Storey et al., 2004; Langmark et al. , 2005) . The most effective means of consistently ensuring the safety of drinking and recycled water distribution is through the use of a comprehensive risk assessment and management strategy char encompasses all steps in water supply from treatment to consumer (WHO, 2004; NHMRC/ ARMCANZ, 2004) including improved water treatment, maintenance of disinfection residual and mains cleaning. Currently hindering the development of microbial risk assessment models however are knowledge gaps in microbial regrowth and pathogen and indicator incidence within distribution systems, subsequent exposure assessment, as well as an absence of reliable dose-response data for any opportunistic pathogen. Opportunistic pathogens and the environmental and water quality parameters chat regulate their growth within a distribution system are inherently comp lex, although pipe biofilms are thought to be the primary site for growth. No single parameter influences the extent of pathogen incidence; rather a complex synergism exists between a suite of environmental factors, che exact n ature of these being largely unknown. Whilst it is therefore difficult to establish cause and effect relationships between environmental parameters and pathogen incidence, hydraulic demand, temperature and disinfectant residual were che factors deemed most important in chis study. Ocher factors can include the level of treatment, pipe material, hydraulic conditions and general system condition and should also be taken into consideration.

Further work should therefore investigate mechanical mains cleaning (i.e. flushing, air scouring and swabbing) and quantify its efficacy in microbial risk management.

Conclusions The opportunistic pathogens project has identified a number of knowledge gaps and priority areas for research into the distribution of d rinking and recycled waters. First and foremost chis study highlights the role char temperature plays in che incidence of microbial pathogens, which has important implications in northern regions of Australia, where utilities may need to exercise greater cautio n in respect to microbial regrowth. Furthermore, the current study demonstrates the importance of maintaining dis infectant residual in a distribution system as well as an adequate hydraulic demand, given the absence of both coincidi ng w ith che detection of Naegleria and Legionella in the Darwin discribucion system. Opportunistic pathogens are found commonly in the environment though chis very rarely translates into incidence of illness or disease clusters. Given chis anomalous relationship , it is therefore important to adopt a pragmatic approach to their incidence within a distribution system. Outcomes of this study will assist the development of management protocols for opportunistic pathogens with in distribution systems and aid the ongoing refinement of local and international drinking and recycled water guidelines.

Acknowledgments The authors gracefully acknowledge the financial and in-kind contribution of che following organisations; CRC for Water Quality and Treatment, CSIRO, Sydney Water Corporation, U niversity of New South Wales, ACTEW/AGL, Ecowise Environmental, Melbourne Water, Power and Water Corporation, South-East Water Led , Water Corporation WA, SA Water Corporation, United Water I nternational, PachWest and Australian Water Quality Centre. Furthermore, the authors would like to gracefully acknowledge the

Simulate pressure transients and water hammer in pipes, networks, branches and loops including vapour cavitation. Investigate equipment performance such as air chambers, air release va lves, surge tanks etc. View the transients propagate along pipes in rea l tim e and pressure variations at se lected locations for co nditions such as pump trip and va lve closure. Draw the pipe system and enter equipment data using intuitive Windows graph ics.

Journal of the Australian Water Association

H 2000PtyLtd

Tel: (08) 9364 2211 info@accutech2000.com.au www.accutech2000.com.au

Cost invaluable assistance of Adam Lovell, D a mmika Vitanage, David Gregory, C lare Dixon, C hrisrobel Ferguson, Stephanie Rinck-Pfeiffer, Bret Robinson , Richard Walker, Andrew Wyber, Avram Levy, Tim Inglis, Paul Hearon and Kathryn Green.

The Authors Dr Michael V Storey (corresponding au thor) was a Research Scientist with CSIRO during th is stud y, a nd currently works as a Project M anager in Science and Technology at Sydney Water Corporation, michael.srorey@sydneywater.com .au ; Christine E Kaucner is a research assistant at the U niversity of New South Wales; Dr Mark L Angles is a Project Manager in Scie nce and Tech nology at Syd ney Water Corporatio n; Dr Judy R Blackbeard is Program Manager, Wastewater at the CRC for Water Q uality a nd Treatme nt; Professor Nicholas J Ashbolt is currently Senior Water M icrobiologist at the National Exposure Research Laboratory, US E nvironmemal Protection Agency in C incinnati.

References Ash bolt, N. J. (2003)

Methods co identify and enumerate fra nk and opporrunistic bacterial pathogens in water and biofilm s. In Bartram, J., Cotruvo, ]., Exner, M., Fricker, C. & Glasmacher, A. (Eds.) Hmrotrophic plate counts and drinking-water safety. London, IWA Publishing.

Bartram, J., Corruvo, ]. , Exner, M. , Fricker, C. & Glasmacher, A. (2003) Heterotrophic plate counts and drinking-water safety. The significance ofHPCs for water quality and human health, London, IWA Publishing.

Effective C,_!!joEnergizer Lagoon Desludging Without Taking the Lagoon off-line! The results speak for themselves !

BioEnergizer is a non-bacterium liquid biostim ulant designed to accelerate the breakdown of sludges in flowing and static wastewaters. BloEnergar rr- ,,... re balance exist! g m1

Proven results in • Municipal wastewater • Industrial wastewater • Pulp and paper mills • Dairy farms and piggeries • Cut sludge handling costs • Decrease polymer cost • Improve sludge digestion

• Cut aeration costs • Increase lagoon capacity • Enhance wastewater biology • Eliminate lagoon downtime • Reduced foaming • Increased settlability • Lower BOD/COD levels

Before BloEnerglzer Solids virtually filling entire lagoon. Lagoon out of effective service

Emmerson, A. M. (2001) Emerging waterborne infections in healthcare setrings. Emerging Infectious Diseases, 7, 272-6. Fields, B. S., Benson, R. F. & Besser, R. E. (2002) Legionella and Legionnaire's disease: 25 years of investigation. Clinical Microbiology Reviews, 15, 506-526. Ford, T. E. ( 1999) M icrobiological safery of drinking water: United Srates and global perspect ives. Environmental Health Perspectives, I 07, 191-206.

After 1 month Of BloEnerglzer treatment solids beginning to break

Gerba, C. P. , Rose, J.B. & Haas, C. N . (1996) Sensitive populations: Who is at the greatest risk' International journal of Food Microbiology, 30, 113-123. Inglis, T . J., Garrow, S. C., Henderson, M. , Clair, A., Sampson, J., O'reilly, L. & Cameron, B. (2000) Burkholderia pseudomallei traced co warer rreatment plane in Australia. Emerging Infectious Diseases, 6, 56-9. Ungmark, J., Storey, M. V., Ash bolt, N. J. & Stenstrom, T. A. (2005) The accumulation and fate of microorganisms and microspheres in biofilms form ed in a pilot-scale water disrriburion system. Applied and Environmental Microbiology, 71, 706-712. NHMRC/ARMCANZ (2004) Australian D rinking Water Guidelines. Summary. National Health and Medical Research Cou ncil and the Agricultural and Resource Management Council of Australia and New Zealand. Rusin, P.A., Rose, J. B. , Haas, C. N. & Gerba, C. P. (1997) Risk assessment of opporrunistic bacterial pathogens in water. Reviews in Environmental Contamination and Toxicology, 152, 57-83. Storey, M . Y., Langmark, J., Ashbolt, N. J. & Stenstrom, T. A. (2004) The fare of legionellae within distribution pipe biofilms: Measurement of their persistence, inactivation and derachmenc. Water Science and Technology, 49, 269-275.

After 2 months Of BloEnergizer treatment significant reduction in solids, water now flowing through system

After 4 months Of BioEnergizer treatment sludge blanket almost gone. High water flow, lagoon returned to operational status

Szewzyk, U., Szewzyk, R., Manz, W. & Schleifer, K.-H. (2000) Microbiological safety of drinking water [Review] . Annual Review ofMicrobiology, 54, 81-127. Vally, H., Whittle, A., Cameron, S., Dowse, G. K. & Watson, T. (2004) Outbreak of Aeromonas hydrophila wound infecrions associated with mud football. Clinical lnfectiow Diseases, 38, 1084-9. WHO (2004) Guidelines for drinking water quality. Recommendations. 3rd Ed, Geneva, World H ealth Organizat ion.

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Water

FEBRUARY 2008 45

.fereed paper

WATER REUSE PROJECTS: THE ROLE OF COMMUNITY SOCIAL INFRASTRUCTURE GB Keremane, J McKay Abstract This paper is based 011 the experiences of implementing cwo water reuse schemes for horticulture in South Australia. It focuses 011 Community Social In frastructure, an important ingredient in successful implementation of such schemes.

SOUTH AUSTRALIA

Introduction Urban wastewater reuse for non-potable applications can augment water supplies, but successful implementation is a multifaceted challenge requiring inputs beyond mere tech nical. T his is mainly because wastewater man agement is a complex set of organised efforcs and actions chat requires proactive participation and contribution of various governmental and non-governmental stakeholders. Successful integration of water recycling into water management plans faces several barriers such as public acceptance & participatio n, environmental & health issues, technology co treat water co an appropriate standard, costs compared co ocher water sources, and private sector involvemen t. Addressing these issues requires mainly three factors: (1) involvement of all the stakeholders from the very beginning; (2) lin king the wastewater sector co ocher economic sectors co ensure financia l stability and sustainability, and (3) innovative financ ial mechanisms, including private sector involvement. Focusing o n the first factor, 'social capital provides a framework for collective action- building shared solutions to a joint p roblem through negotiation and d ialogue processes chat are necessarily and inherently social' (Wo olcock, 20 04, p.1 88). Apart from individual leadership and physical infrastructure, a third component 'social infrastructure' is very important and it links the indiv id ual leadership co physical

Success or failure of any wastewater reuse project largely depends on the community participation. 46

FEBRUARY 2008

Water

Gulf Vincent

Figure 1. Location of the study sites in South Austra lia (note: figure not to scale).

infrastructure (Flora and Flora, 1993) . In line with chis, chis paper focuses on the importance of 'community social in frastructure' in implementi ng water reuse projects.

The Approach Two water reuse p rojects operating near Adelaide: (1) Virginia Pipeli ne Scheme (VPS) and (2) Willunga Pipeline Scheme (WPS) were selected for the srudy. Initial exploration of both the research sites (see Figure 1) in Sou th Australia revealed that altho ugh similar in terms of the objective, the schemes were u nique in their own right and had d ifferent organisational setups (Gransbury, 2000; Kelly & Stevens, 2000). Boch schemes have performed well since their incep tion. Data were co llected through reviews of project documents and interviews with the irrigacor's - face -co-face and telephone interviews, in the case of VPS and WPS respectively. Key stakeholder interviews were carried o ut to gather information about the issues pertaining co the theme of the study, such as the history of the schemes, management practices, and co augment the information gathered through

Journal of the Australian Water Association

the ho usehold and telephone interviews . A structured questionnaire with a mix of question types (Likert scale, multiple choice etc.) was used. In case of the VPS, since most of the irrigacors belonged co nonEnglish speaking community (domin ated by people from V ietnam and Cambodia) interpreters were hired and the q uestionnaire was translated into Vietnamese and Khmer co faci litate the interview p rocess. The telephone interviews with the WPS irrigacors were conducted by the professional interviewers at the Marketing Science Centre, University of South Australia.

Outline of the Two Water Reuse Projects Although both schemes are reuse schemes they differ from each other in some aspects (see Table 1). The VPS is built o n the b uild-own-operate-transfer (BOOT) model, and is the largest of its type in the wh ole of Australia (Keremane and McKay, 2006). The scheme is a co-operative undertaking of the Virginia lrrigacors Association (VIA) - representing market gard eners and ocher irrigators; SA Water Corporation (p ublic sector) and Water Reticulation Services Virginia (WRSV) (a private company). The

Table 1. Attributes of the schemes under study. Attribute

Virginia Pipeline Scheme

Willunga Pipeline Scheme

Location

Northern Adelaide Plains region

Mclaren Vale region

Date of commissioning PSP option/model

1999 BOOT

Divestiture

Main source of reclaimed water

Bolivar Sewage Treatment Plant (BSTP)

Christies Beach Wastewater Treatment Plant (CBWWTP)

Number of contracts

252

Capacity

120 mega litre/day

46 mega litre/day

Cost of construction

AUD 22 million

AUD 7.2 million

Length of pipeline

l 00kms

Water class/quality

'A'

l 3.2kms '8'

Used for

Irrigate market gardens

Irrigate vineyards

1999

Source: Initial exploration of study site private water company won a contract from the SA Water Corporation co access the o utput from the treatment plane, and also signed up clients for the reclaimed water and built the water d istribution system. Since rhe project is built on the BOOT model, the project will be returned to the ownership of SA Water by WRSY in 201 9, at rhe end of the contract term. As of 2005, the scheme su pp lies C lass-A treated water co around 252 irrigacors on the Northern Adelaide Plains (NAP) in South Australia.

Role of Community Social Infrastructure in Implementing Water Reuse Projects Wastewater reuse history is marked with fai lure of reuse projects mainly because of lack of community involvement (Po, J uliane & Nancarrow, 2004; Hurlimann & McKay, 2006). According co Jones (2005), working with a commun ity char does nor have wastewater as a highest priority requires building participation through a combination of discussions about community outcomes, and more derailed action seeps of technology identification, design work, and management. T he author further suggests char lack of community participation results in a wide gap between what is desired from wastewater reuse and what is necessary co get there, and inability to bridge chis gap is the primary reason for fa ilure of locally driven wastewater projects. Since ir is the public who will be served by and pay for chem, the policies on wastewater use and management muse include rhe human dimension (Robi nson , Robinson & Hawkins, 2005). Therefore, for a reuse project co be successful com munity involvemen t and/or participation are very important and social infrastructure p rovides a framewo rk for bu ilding shared sol utions co a joint p roblem through negotiation and dialogue processes

On rhe ocher hand, the WPS is the result of a licensing agreement negotiated between rhe Willunga Basin Water Company (WBWC) and the SA Water Corporation ro access reclaimed water from the C hristies Beach wastewater treatment plant for 40 years. The WBWC is a joint venrure company formed by a consortium of grape growers and winemakers, which owns the p ipeline and is responsible for its operation and maintenance. Unlike rhe VPS , chis scheme did not receive any kind of financial support or subsidy from the public sector. All rhe costs were mer by rhe WBWC. Since its inception in 1999, the scheme has expanded and today supp lies Class B water co around 80 beneficiaries. A second wave of users, as a third party, were required co sign water supply agreements with the WBWC.

Table 2. Stages of participation. Four

Five

Six

Seven

Information-shoring

Consultation

Joint-decision making

Participation

Initiation and control by stakeholders

Collaboration

Co-determination

Empowerment

Joint responsibility

Empowerment

Control by stakeholders Partnership Control by stakeholders

(Woolcock, 2004; Flora and Flora, 1993). Success here implies meeting the desired outcomes for all the parties involved, co all the parties' satisfaction. Since the projects under study, for that marrer any water reuse projects, involve an entire co mmunity the term 'community social infrastructure' is used in this srudy. Before discussing the concept of Community Social Infrastructure, a brief note on communi ty participation is presented co set the scene.

Community participation Community participation is nor new co the water sector, as rhe governmen ts of several coun tries, the World Bank and ocher multinational financing agencies, and donors are promoting rhe con cept of decentralisation for managing water resources (Mody, 2004). Participation is a broad term with many variations in its meaning and in terpretation; in simple terms it can be expressed as nominal membersh ip, while in a broader sense ir can be defined as a process in which people have voice and influence in decisionmaking (White, 1996). l n the political sense, it is a principle char allows citizens co rake part in the political process (Heyd & Neef, 2004). According co Sinha and Suar (200 5) there are two dimensions co participation - d irect and indirect - while other scholars like Pretty (cited in Heyd and Neef, 2004) give a more derailed classification with seven forms of participation. Eberlei (200 1) argues char in recent literature, between four and seven degrees of participation are distinguished (see Table 2).

Social capital T he role of social capital is viral in policy studies, yet planners and policy makers often fai l co understand chis concept. There is a growing body of lirerarure char examines the importance of social capital in

Source: Adapted from (Eberlei, 2004)

Continued on page 50 Journal of the Australian Water Association

Water

FEBRUARY 2008 47

PUMP & PIPING TRAINING PUMP FUNDAMENTALS '.

Seminar Objectives At the completion of this seminar, each delegate should be able to: • Identify common centrifugal and positive displacement pum p types and their components. • Understand pump, associated component, hydraulics and slurry terminology. • Select the most appropriate pump type, make and model for a particular application. • Be competent in reading and using pump performance curves. • Understand cavitation, how to design it out of the system and how to correct an existing system experiencing cavitation related problems. • Specify the correct installation configuration fora particular pump type of application. • Install, commission, operate and maintain common pump types. • Troubleshoot pump problems. • Feel comfortable when dealing with pump suppliers and be able to double-check their pump selections.

Delegate Pre-Requisites It is a requirement that each delegate has an understanding of mechanical components. A basic understanding (trade level) engineering maths would also be advantageous.

BACKGROUND INFORMATION Terms and Definitions Fluid Properties Basic Hydraulics Theory and Calculations Cavitation Friction Losses in Pipes and Fittings Pump Classification and Exam ples Pump Selection Guidelines CENTRIFUGAL PUMPS Components, Types and Examples Affinity Laws and Characteristic Curves Matching the System to the Pump System Curve Calculations Viscosity Effects Parallel and Series Pumping Troubleshooting

EDUCTORS (JET PUMPS) Principle of Operation Applications SEALS AND PACKING General Overview Components and Types Applications and Selection Installation, Maintenance, Troubleshooting PUMP DRIVES General Overview Canned and Magnetic Setups 'Belts, Gearboxes, Mechanical Variators Electric Motors and Inverters Other Drive Types

INTRODUCTION TO CENTRIFUGAL SLURRY PUMPS Slurry Classifications and Rheology Slurry Characteristics Solids Content and Settling Velocities Typical Components and Assemblies Characteristics Curves Selection Criteria POSITIVE DISPLACEMENT (PD) PUMPS PD Pump Theory Typical System Curves Comparison to Centrifugal Pumps

Who Should Attend?

PD PUMPS (CONTINUED) Common PD Pumps - (Gear, Lobe, Progressive Cavity, Piston, Diaphragm, Peristaltic) Selection Guidelines Troubleshooting

INSTALLATION & MAINTENANCE Foundations and Bases Alignment Recommended Piping Configurations Condition Monitoring Preventative Maintenance General Installation and Maintenance Tips

Seminar Materials

•The "Pump Fundamentals" Training Manual - a reference manual comprising Process, Design, Project and Consulting theory, worked example problems, tables and Engineers. charts, illustrations etc based on the training seminar outline. This manual has been Line Managers and Supervisors. designed to be a valuable future resource for Maintenance Technicians. Pump Sales Representatives. the office, workshop, factory or plant. Anyone who needs to select, specify, commission, install and/or maintain pumping • Certificate of Attendance - which states the number of hours of training and serves as equipment. documentary proof of attendance.

This seminar has been designed for:

Pump Fundamentals Seminar Sydney 1 & 2 April 2008

Liquid Piping Fundamentals Seminar Sydney 3 & 4 April 2008 Rydges Hotel Parramatta

The Rydges Hotel Parramatta

Brisbane

8 & 9 April 2008

Brisbane

Perth

14 & 15 April 2008 The Mercure Hotel Perth

10 & 11 April 2008 The Chifley at Lennons, Brisbane

The Chifley at Lennons, Brisbane

Perth

16 & 17 April 2008 The Mercure Hotel Perth

SEMINARS -APRIL 2008 LIQUID PIPING SYSTEMS FUNDAMENTALS DAY1

DAY2

BACKGROUND INFORMATION Terms and Definitions Fluid Properties Basic Hydraulics Theory and Calculations Cavitation & Water Hammer Friction Losses in Pipes and Fittings Scaling Pipe Sizing Methods Pipe Manufacturing Methods

DESIGN & DRAFTING Piping Specifications Drafting Symbols Process Flow Diagrams, Piping & Instrumentation Diagrams, Line Lists, Plot Plans, Layouts, Isometrics, Spool Drawings

SELECTING PIPE AND FITTINGS Common Codes and Standards Materials of Construction Connections - Screwed, Flanged etc Gaskets and Jointing Materials Fittings VALVES Common Valve Types - (Ball , Butterfly, Globe, Gate, Pinch, Angle, Needle, Check, Pressure Reducing, Solenoid, Vacuum/Pressure Break, Pressure Relief, Diaphragm, etc) Materials of Construction Valve Actuators Valve Selection and Sizing Guidelines Control Valve Selection and Sizing INSTRUMENTS Typica l Instruments Found in Piping Systems Selection Guidelines

GUIDELINES FOR PIPING LAYOUT General Overview Maintenance and Operating Requirements Process Requirements Safety Considerations PIPE SUPPORT SYSTEMS General Overview Rigid, Variable and Spring Supports Applications and Selection Introduction to the Design of Pipe Supports INTRODUCTION TO PIPING DESIGN LOADS Sustained, Occasional and Thermal Loads Basic Manual Calculation Methods for Simple Loading Problems MISCELLANEOUS TOPICS Insulation and Tracing Fabrication and Erection Filters, Strainers, Static Mixers etc

SEMINAR FEE: $1,295.00 each (inclusive of GST) 10% discounts apply for (i) Previous KASA seminar attendees, and/or (ii) a multiple seminar registration , and/or (iii) three or more registrations from the one company at the same time, and/or (iv) registration prior to 5:00pm Sydney time on Friday 14 March 2008. The maximum discount claimable shall be limited to 20%. For more information on these two day seminars (including a full seminar synopsis) and to obtain registration forms and cond itions, cal l KASARedberg on (02) 98681111 or email info@kasa.com.auorvisitwww.kasa.com.au. KASARedberg Ply Ltd,ABN 35107 585 375, Ph: (02) 98681111 , Fax: (02) 8246 6387 Suite 2, 42 Langston Place, PO Box 147, Epping , NSW 1710

technical features

Continued from page 47 organising groups to cake a collective action and couple social capi tal with development (Paldam, 2000; Putnam 2004; Ostrom 1990; D ietz, Ostrom & Stern, 2003). In the social capital literature we come across various definitions for social capi tal. Social capital is a person's or group's sympathy coward s another person or group that may produce a potential benefit (Robison, Schmid & Siles, 2002). According ro Putnam (2004), social capital includes networks, norms and t rust. While d iscussing social capital we come across many perceptions about the concept; some scholars fo cus on dense networks (Dietz, Ostrom, & Stern , 2003); some o n values and connections (Sen, 1995); and some argue that citizen engagement, interpersonal trust, and effective collective action are what form social capital (Ro he, 2004). Irrespective of the variations in the percep tion about social capital, it is apparent that the social capital theory encompasses three aspects: (i) groups and networks, (ii) trust and solidarity, and (iii) cooperation. In the p resent context, since success or failure of any wastewater reuse p roject

Table 3. Characteristics of social infrastructure . Dimensions of socio! infrastructure

Characteristics

Symbolic diversity

Communities engage in constructive work to arrive at workable commu nity decisions; intense and frequent interaction between community members

Resource mobilisation

Willingness to invest collectively, wi llingness to invest private copital locally

Networks

Diversity, horizontal network, vertical network

Source: Flora and Flora, 1993 Table 4. Community social infrastructure in Virgi nia and W illunga pipeline scheme. Dimensions of social infrastructure

Virginia pipeline scheme

Willunga pipeline scheme

Symbolic diversity

+++

++·

Resource mobilisation

++·

+++

Networks

+++

largely d epends on the com munity participation and involvement it makes it important to measure the social capital at the community level and maintaining social capital means social sustainability (Keremane and McKay, 2007). Putnam (1993) has measured indicators of social capital on provincial and national level;

I~ Fulton Hogan

Coleman ( 1988) has addressed social capital on an individual and household level.

Community social infrastructure meaning and dimensions This study adopts the concept of 'Social Infrastructure' (Flora and Flora, 1993) which is an important mechanism of institutional analysis as a basis for change. According to the authors social infrastructure means chat communities begin to look at making sloes rather than fitt ing into sloes; entrepreneurial social infrastructure means communi ties begin co look at risk, both collectively individually, in a different way (Flora and Flora, 1993, p. 58), and it has three major dimensions:

• Symbolic diversity implies a collective o r communi ty level orientation coward inclusiveness rather than exclusiveness ,

This change makes Fulton Hogan one of the largest trans-Tasman civil contracting company and builds on more than 70 years experience in New Zealand and Australia.

• Resource mobilisation implies chat

Fulton Hogan will continue to offer the same quality products and services aaoss a @nge of civil contracting disciplines including;

communities must be ever more dependen t on their own resources if development is to occur, and

· Civil construction

· Pipeline conS11Uction and;

· Qual1)1ng

· Infrastructure maintenance

· Asphalt supply and laying

• Linkages or networks means chat networks, formal and informal, within the community and with the ou tside, facilitate the flow o f resources, and so broad linkages are important. As noted in Table 3 communities with high symbolic diversity engage in constructive work to arrive at workable community decisions and the members will be having incense and frequent interaction among themselves. Similarly, when communities are willing to invest collectively and also invest p rivate capital locally for the benefit of the community it is believed chat such communities are positive towards resource mobilisation. Further, communities with quality linkages both, within the community (horizontal) and outsid e (vertical) have increased social capital.

50 FEBRUARY 2008

Water

Journal of the Australian Water Association

Measure of social infrastructure in the two projects

Table 4 presents the level of community social infrastructure in relation co che rwo projects under study. Overall, both projects exhibit increased community social infrastructure although ic is comparatively higher in case of che Virginia pipeline scheme. When compared co che Will unga pipeline, che Virginia pipeline scores high on symbolic diversity and che quality of linkages. This is attributed co che face chat irrespective of che group heterogeneity (che irrigacors belonged co different cultural backgrounds and ethn icity) chey were having frequent and regular interactions amo ng themselves. Tn addition, che trisector partnership formed between che private sector, public sector and che community via BOOT model had resulted in quality horizontal and vertical networks. The low score in case of WPS on these cwo dimensions is mainly because of che model on which che scheme is built. The study observed chat in case of WPS ic was a homogenous group of itrigacors and by virtue of che divestiture model most of che interactions were limited within che investment cohort and the chi rd party users. However, WPS scored higher in resource mobilisation because the entire scheme was fu nded by che consortium of growers without and public sector support. This implies chat che community's willingness co invest collectively and more importantly invest private capital for che benefit of che entire commu nity. In addition co these three dimensions, cruse is one of che most freque ntly encountered elements in definitions of social capital and is an indication chat social capital plays an important role in sustainable development (Danchev, 2005). As argued by Danchev (2005, p. 26), "there is no evidence that deterioration of social capital can be compensated fo r by the rise of ocher forms of capital; on che contrary, when we observe the worsening of social capital, all ocher forms of capital including development deteriorate". Therefore, building social capital can be a powerful mechanism for plan ners who seek co promote greater equity in and across cities (Vidal, 2004 p. 164). Thus, social capital makes a difference in terms of a community's ability co solve ics own problem (Flora, I 995). Since, wastewater management involves different stakeholders; in che present case ic is che Government, Environment Protection Auchoricy, Department of Health services, che Water Company and the community, ic is important co measure che level of confidence che irrigacors' have

1.5

1,-----

"~:~ ). ._____411_4____-___J~ Water company

----~-::-'-3___

8116

_,J

17.2

8118

10%

20%

30%

40%

50%

P e rc e natge

60%

700/4

80%

90%

100%

or lrrl ga tors

I c High • Medium o Low a Indifferent j

Figure 2a. lrrigators' level of trust in case of Virg inia Pipeline Scheme.

Health

316

••

EPA

Water company

82.8

Go,.;

158

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Porco na tg o of irrigators

IDHigh • Medium o Low o Indifferent I Figure 2b. lrrigators' level of trust in ca se of Wi llunga Pipeline Scheme.

in che fellow irrigacors and the various agencies involved in implemencacion of the scheme. As fa r as crusting che fellow irrigacor is concerned the three dimensions of social infrastructure, symbolic diversity and network in particular, indirectly measure the level of cruse within che community. However, che study went on measure che level of confidence chat irrigacors, in both che schemes, had in various associated agencies which is presented in Figures 2a and 26. In both che schemes, che irrigacors' had high co medium level of cruse in che related agencies. However, arou nd 16 percent of che irrigacors' in case of WPS had low cruse in che government and only IO percent fu lly crusted the government because of the face that the scheme received no fina ncial support from the government(s) as opposed co VPS which did receive financial support.

Conclusions Experience from these t\vo projects suggests that Social Capital and Community Social Infrastructure are essential ingredients in implementing water reuse project as they link the physical infrastructure co individual leadership. The Virginia pipeline scheme demonstrates char it is possible co achieve

increased social capital even with heterogeneous or diverse groups. The Wi ll unga pipeline scheme on the other hand demonstrates what can be achieved when people come cogecher co cackle water scarcity challenges on their own. Further, confidence in the associated agencies co deliver and perform their duties effectively is also crucial in implementi ng a reuse project. In addition, these projects exemplify the benefits of involving all che stakeholders through effective partnerships which include: utilisi ng che experience of che private sector co improve service delivery, shifting che role of government from being a service provider co a facilitaror for service provision, and improve che relationships between public and private sector and che community to work in partnership for mutual benefit and che general public good. Finally, a favourable policy and regulatory regime is also instrumental in ensuring successful implementation of a water reuse proJecc.

References Ausrralian Bureau of Statistics. (2005). Water Accountfor Australia 2000-01, (Report no. 4610.0. ABS). Canberra, Australian Capital Territory: Author.

Journal of the Australian Water Association

water

FEBRUARY 2008 5 1

refereed paper

Coleman, S.J. (1988) . Social Capital in rhe Creat ion of Human Capital. The American journal ofSociology, 94, 95-120. Oanchev, A. (2005). Social capital influence on sustainability of development (Case study of Bulgaria). Sustainable Development, 13 (2005), 25-37. Dietz, T. , Ostrom, E., & Seem, P. (2003). The Struggle to Govern the Commons. Science, 302, 1907- 1912. Eberlei, W. (200 I). Institutionalised participation in processes beyond the PRSP. Study commissioned by GTZ, Eschborn, Institute for D evelopment and Peace (INEF), Gerhard-Mercator-University, Duisburg, September 200 l. Flora, C. B. (1995 ). Social capital and sustainability: Agriculture and communities in the Grear Plains and Corn Belt. Research in Rural Sociology and Development, 6, 227246. Flora, C. B. & Flo ra, J. L. (1993). Entrepreneurial social infrasrrucrure: A necessary ingredient. The Annals ofthe

Academy ofSocial and Political Sciences. Gransbury J (2000) . The Willunga Basin Pipeline - Stage 1. Water 27 No. 5 pp 27-3 1 Heyd, H. , & Neef, A. (2004). Participation of

local people in water management - Evidence from the Mae Sa watershed, northern Thailand, (Discussion Paper No.128). Environment and Production Technology

Division, International Food Policy Research lnscirure (I FPRI), Washington, DC. Jones, K. (2005). Engaging community members in wasrewarer discussions. EcoEng Newsletter, Number 11 , October, 2005. Kelly J, Stevens D (2000). From Problem co Profit ... the Northern Adelaide Plains. Water 27 No 5 pp 37-41 Keremane, G. B., & McKay, J. (2007) . Successful wastewater reuse scheme and sustainable development: a case study in Adelaide, Water and Environmental journal, 21(2), 83-9 l. Keremane, G. B. , & McKay, J. M. (2006). The role of community participation and parrnerships: T he Virginia pipeline scheme.

Water, journal ofthe Australian Water Association, 29(34), 29-33 . McKay, J.M. , & Hurlimann, A. (2003). Attitudes to reclaimed water for domest ic use: Parr 1. Water, journal ofthe Australian Water Association, 30(5), 4 5-49 .

Paldam, M. (2000). Social Capital: O ne or Many? Definition and Measu rement. journal ofEconomic Surveys, 14(5), 629-653 . Po, M., Juliane, K., & N ancarrow, B.E. (2004) .

Literature Review ofFactors influencing Public Perceptions of Water Reuse. Australian Water Conservation and Reuse Research Program. CSIRO. Putnam, 0. R. (1993). The prosperous community: Social capital and public life. The American Prospect, 13, 35-42. Putnam, 0. R. (2004). Preface. Journal ofthe American Planning Association, 70 (2), 141143. Robinson, K. G., Robinson, C. H. , & Hawkins, S. A. (2005). Assessment of public perception regarding wastewater reuse. Water Science and Technology: Water Supply, 5(1), 59-65. Robison, J. L., Schmid, A. A., and Siles, E. M. (2002). Is Social Capital Really Capital. Review ofSocial Economy, 60( 1), 1-21.

H url imann, A. & McKay, J . M. (2003) . Attitudes to reclaimed water for domestic use: Parr 2. Trust. Water, journal ofthe Australian Water Association, 31(5), 45-49.

Sen, A. (1995). Rationality and Social Choice. American Economic Review, 85(1), 1-24.

Mody, J. (2004) . Achieving accountability through decentralisation: Lessons for integrated river basin management. Policy Research Working Paper 3346. T he World Bank: Washington, DC

International journal of Rural Management, I (I ), 125-143.

Sinha, H., & Suar, D. (2005). Leadership and people's participation in community forestry.

Vidal, C. A. (2004) . Building Social Capital to Promote Community Equity. journal ofthe American Planning Association, 70(2), 164168. White, S. (1996) Depoliticizing development: The uses and abuses of participation. Development in Practice, 6(1): 6-15 . Woolcock, M. (2004). Why and How Planners Should Take Social Capital Seriously.

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Journal ofthe American Planning Association, 70(2): 183- 189.

Acknowledgments

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The authors thank the University of South Australia and the C RC for Irrigation Futures fo r providing financial support to carry out the study. T he authors extend their deepest grat itude to the participants of the survey and the management of both the reclaimed water schemes for their time and cooperation.

The Authors Ganesh B Keremane is with the Centre fo r Comparative Water Policies and Laws, School of Commerce, University of South Australia. This paper is based on his PhD research work that looked at the governance regimes and institutional arrangements for urban wastewater reuse in agriculture. Email: ganesh.keremane@unisa.edu.au; Jennifer McKay is Professor of Business Law and D irector of the Centre for Comparative Water Policies and Laws, University of South Australia. Email: J enn ifer. Mckay@unisa.edu. au

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DECENTRALISED WATER SUPPLIES: SOUTH-EAST QUEENSLAND HOUSEHOLDERS' EXPERIENCE AND ATTITUDES A Gardiner, P Skoien, T Gardner Abstract The use of decentralised water sources, including rainwater tanks, onsice water treatment systems and dual reticulation system s are playi ng an increasing role in the management of urban water resources. The successful implementation of decentralised water su pp ly options depends on the acceptability and safe management of new systems at rhe household level. We report on a study of nearly 500 tank owners in South Ease Queensland, and 102 residents of develop ments with dua l reticulated recycled water, who were surveyed in June and July 2007. This srudy compares rhe maintenance practices, reuse behaviours and morivario ns of three disrincr groups; urban ' rerrofirrers', 'peri-urban ' residents with established ranks, and residents of 'greenfield' estates where rainwater ran ks and/or a dual reticulated supply has been mandated . Disti nct differences in the use of rainwater tanks are found between these three grou ps. Co nclusions highlight the difficulty in promoting the co nnection of rainwater tanks for internal ho usehold purposes and the need for on-going commu nication in estates with dual reticu lation of recycled water. New tank owners, especially where ranks are mandated through development cond itions, have yet to learn how to maintain their systems or uti lise their tank water effectively to reduce mains consump tion.

Introduction P romotion of alternative water sources is an important strategy in managing the increasing demand for water in urban areas. However, little is known about the knowledge, attitudes and practices of households who have experience with a decentralised urban water supply, and the role of the community as social actors who shape the outcomes of decentralised initiatives such as tanks, greywater reuse and reticulated reclaimed water supply. In South East Queensland (SEQ), the uptake of these technologies has been accelerated by legislation over new development and incentive-based programs.

sociological theories and models to understand and explain resid ential experience with rainwater ranks and recycled water for no n-potable pu rposes (e.g. Hurl imann & M cKay, 2004; Marks, 2004; Russell , 2002; 2004); (3) research into the organisational and inst itutional arrangements co ncerning the implementation of decentralised urban water supply systems as alternatives to m unicipal water supplies (e.g. Brown, 200 4; Livingston et al., 2006), and marker sryle research, as ch is study is, that m easure behavio urs and attitudes to recycled warer (Roseth 2006).

Methodology

In January 2007 the Queensland Governmen t introduced legislation requ iri ng all new detached houses in SEQ co save 70 kilolitres per year through the use of rai nwater ranks, dual reticulation, communal rainwater tanks and stormwater reuse (Queensland Governmen t, 200 6). In new housing developments, centralised water su pply must now be supplemented by decentralised water systems (Queensland Government, 2007a). T he WaterWise Rebate Schem e, implemented in June 2006 in SEQ and extended to the whole of Queensland in late 2006, offers subsid ies for rainwater tanks, water efficient internal fitt ings and greywater systems. While a number of stud ies have addressed the motivations that could drive the purchase and installatio n of tanks or connection to dual supply, few studies have fo llowed residents' attitudes and behaviours afterwards. There are fou r main areas of social science research in relation to alternative urban water supply and systems in Australia. These are: (1) studies that have used psychology based behavioural models to predict stakeholder attitudes an d behavioural intention towards variou s options (e.g. Nancarrow et al., 1996-7; Po et al., 2005); (2) studies that have employed

Three g1oup~ w,u., diffe,.ent motivations.

This study is rhe first of a th ree-stage longitudinal survey of attitudes and experiences with rainwater ranks and dual supply systems using a statistically robust sample of 600 residents. Two catego ries (pe ri- urban and retrofit), of 200 residents each , who have had a rai nwater rank for ar lease six months were su rveyed using a computer assisted telephone interview (CATI) by Enhance Managemen t. The 'peri urban' cohort was randomly chosen from areas nor serviced by a municipal supply an d were d rawn from rhe Maleny (I 4), Beaudeserr (156) and Tambourine Mountain (31) areas (Figure 1: map). Two hund red 'recro fitters' were selected as a random sample from approximately 30,000 SEQ recipients of rank rebates under the Queensland Home Warerwise Rebate Scheme. The sample size provides a maximum m id range sampling variation of ± 4% at a 95% level of confidence (Enhance Management 200 7, 17). Identifying a representative sample of residents of 'greenfield' estates firred wirh dual reticulation supplies who also had rainwater tanks was difficult as council requirements for this came in to effect in January 2007. In new developments teleph one records were not searchable so face-to-face interviews were conducted in targeted clusters. Respondents were chosen from four estates, of which two require residents to install rain warer tanks Oacobs Ridge at Ormeau on the Gold Coast and Sanctuary Pocket in South West Brisbane).

Journal of the Australian Water Association

water

FEBRUARY 2008 53

technical teatures d aper

The ocher cwo are located in che PimpamaCoomera develop ment zone on che Gold Coast where a reciculated recycled water supply system is being established, and is currently supplying potable water. The recycled water treatment plant will be operating in 2008. In total, 135 of the 200 greenfield respondents had a rainwater tank and 102 had dual reticulation of whom 37 h ad both a tank and dual reticulation. The surveys comprised a core set of questions applicable to all residents as well as questions relevant to the particular samp le. Survey questions were generated in conjunction with the contractor (Enhance Management), t rialled and revised to remove ambiguous or extraneous questions. Demographic information was collected on household size and family composition, age of the respondent, total household income, working status, and education level. Questions about rainwater tanks included the age and size of their tanks, use of rai nwater; perceived advan tages and disadvantages of owni ng a rainwater tank; satisfact ion with and maintenance of their tanks. Reported behaviours in relation to grey water and ocher water saving practices were reco rded . Four questions addressed perceptions, beliefs and concerns about water sh ortages and the impacts of personal efforts. The questions specific to the retrofitter sub-sample addressed motivations for purchasing a tank; intended and actual use of rainwater; and information sources sought prior to the purchase of the rainwater tank. The questions specific to the peri-urban sub-sample asked about their motivation for living in the area; whether the tank is fitted w ith an electric pump; whether water had ever been delivered to the tank. The questions sp ecific to greenfield sub-sample capped residents' motivation for movi ng to the subdivision; level of awareness and understanding of dual reticulation and water sensitive urban design; intended use of dual reticulation; perceived benefits and disadvantages o f dual reticulation , information sources about recycled water for non-potable usage, and attitudes coward recycled water for non-potable usage.

Table 1. Comparison of ta nk owners. Cohort

54 FEBRUARY 2008

Water

Retrofit (N=200)

Greenfield (N= 135)

45 [73%)

<44 [63%)

Household size [mean)

3.1

55-65+ [63%) 2.9

Tank copacity (kl)

>20

3 ta 5

2 to 3

High [gutters, pipes and inside tank)

High [mainly gutters and traps)

<l Low

Age range

Length of experience [years) Maintenance

3.5

Percentage who use their tank water for: Gardens Outdoor Internal Drinking Percentage who use greywater

87 [62% installed)

lifestyle to any great degree. Nearly all of the respondents had positive attitudes to the tanks and their contribution to water conservation. The very few (7 greenfield residents, 2 recrofitters and 2 peri-urban residen ts) who exp ressed dissatisfaction with thei r tanks complained ab out the inadequacies of the roof collection area, the small tank and lack of internal connection co toilets or laundry. Individual complaints included contam ination in the tank, noisy and expensive to run pump, toilets chat do not function during electricity fa ilure and the lack of a level gauge in the tank. Table 1 presents a summary of tank owners and their wacer practices. The periurban respondents live in semirural environments fo r lifestyle reasons, nominating reasons such as location, rural aspect and open space. They are generally middle-aged with no children at home.

A Comparison of Tank Owners All of che respondents interviewed expressed concern abour water shortages and more than half believe chat not enough is b eing done to address the water crisis in Queensland. Respondents generally felt they were making some form of contribution co the water crisis and chat their contribution was not curren cly inconveniencing their

Peri-Urban (N=200)

Figure 1. The Survey Markets.

Journal of the Australian Water Association

Most had more than one tank. T wo thirds have on occasion had their tanks topped up with delivered water (68%) . The taste and purity of their water was a key issue for chis gro up and co nsequencly their maintenance practices were of a higher standard. Conserving water is a p riority for chis group. The retrofitters are the oldest group and are mainly couples with or without older children and, rarely, one person households. This group installed cheir tanks followi ng Level 5 drought restriccions which allow bucker watering only. Many regarded che wacer collecced as 'theirs' and available to serve their own purposes. While water for ch eir garden was volunteered as the major mocivacion for inscalling cheir rank (by 46%) over 85% use che wacer on cheir gardens, compared wich 37% of peri-u rban rank owners and 57% of greenfield residents wichouc dual supply (Figure 2).

tecnn1ca1 teatures fere d paper

Retroficters were the most satisfied with their rainwater ranks (over 85% very satisfied compared to only 33% of the greenfield respondents). The factor that most commonly determined the size of retrofitted tanks was rhe land available (68%) as opposed to the cost of rhe rank (14%), water use estimates (12%) or the roof area available (3%) . Retrofirrers demonstrated a genuine commitment to savi ng water and many practised ocher water saving strategies such as grey water diversion (63%), bucketing water from the house (46%), shorter showers and installing dual fl ush toilets (35%) or low flow shower roses (40%). Half of the 200 households raced th eir overall water efficiency as a 9 or IO on a scale from 1 (lease) to IO (most), and only 3 respondents rared themselves below 6. T he greenfield residenrs surveyed were generally young fam il ies with children of various ages. Their motivations fo r living in rhe area were mainly fo r geographical reasons, with licrle regard for the WSUD context. Many were double income fami lies and 51% quoted family incomes over $80,000 (ch is may be even higher as 17% refused to answer income related questions). Th is group had significantly

Pool ~

Drinking

Laundry

.., Hot water Bathroom

h 1-------1

Kitchen

I I I I

L..-.....J

J.-..J I

o Greenfield (non dual) • Peri-urban I

I I I I

I I

Washing machine (cold)

Other outdoor

CJ Retrofit

Garden

Toilet

'-------' O'lo

10%

I 20'/o

30%

I 40%

50%

60',4

70%

80'/o

90',4 100%

Figure 2. Uses of tank water. What does your household use the water for? (Greenfi eld responses are from those w ithout d ual supply) .

higher education levels than residents with peri-urban tanks or rerrofirrers. Greenfield residents who had tanks used the water for toiler fl ushing (49%), washing machine (37%), and outdoor uses such as car washing and house cleaning (60%).

[f their self assess ment is taken at face value, rhe greenfield residents with dual reticulation appeared to be less concerned about water savings beyo nd selfco ngratu lations fo r happening to live in an area where water savings initiatives are in

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Journal of the Australian Water Association

Water

FEBRUARY 2008 55

technical features 1

place. Interestingly, although the greenfield group of tank owners rated themselves the lowest at ' having done everything in your control to be water efficient' (only 21 % at very high levels compared with 49% of the retroforers) they were the most likely to have applied each of the top ten reported household water savings actions (Figure 3) . C learly the greenfield famil ies set higher environmental standards fo r themselves than the retrofi tting retirees.

Promoting the Connection of Tank Water for Indoor Uses A previous smaller study in Brisbane (AC Neilsen 2005) identified a wide acceptance for using rainwater for laundry and toilet flushing but this study shows that most residents who installed tanks under rebate schemes d id not do this. Retro firters were asked to compare their expectations from rheir rank with their actual uses of rank water and the patterns matched. Those expecting to use tankwater indoors installed rheir systems with these capabilities from the start. Interestingly there was a slighrly more frequent report of connections to the kitchen and bathroom (13%) than to rhe laundry or hot water system (8% and 6% respectively) even though these were the uses promoted by the council. More than half of both the greenfield sample and the retrofit sample suggested an additional rebate would encourage connection to internal uses. However it is questionable if the garden-focussed retrofitte rs would use their tank water for essential internal uses given regulations which restricts the use of water from any ranks topped u p by a mains supply (Queensland Government 20076).

Attitudes to Recycled Water in Dual Supply Estates Residents of estates with WSUD and dual reticulation displayed patchy knowledge of how the systems function or what constitutes WSUD features. 56% of respo ndents rated their own knowledge about dual reticulatio n tech nology poorly, yet 37% rated their knowledge very highly. The reported understanding of WSUD showed a similar bimodal pattern. This is despite a substantial effort bei ng made to educate residents of these estates by the Council and/or the developers. Interviewers anecdotally reported a high level of rental properties and resident tum-over although this was not a survey question. This may explain the bimodal results if new residents do not receive educational material. T heir decision to live in such estates was a result of the geographic location, convenience and open space as opposed to 56 FEBRUARY 2008

Water

fereed paper

Greenfield

Peri-Urban

Retrofit

People take s horter showers

People take shorter s howers

People tak e s ho rter s hower s

A water efficient shower rose

efficient shower r ose

Only was h dis hes/clothes o n a full load

A dual flu sh toilet

Only wash dishes/clothes on a full load

Don't leave tap running wh en brus hing teeth

Collect wate r fr om bath/shower for use outside

A dual flush toilet

Changing water habits within the house

A water

Divert grey

water

Wate r garden

less or not at all

A dual flush toilet

Divert grey water

A AAA rated or greater front load Ing washing

Don't wash car

Only wash dis hes/clothes on a full load

Don't leave tap runnin g when brushing teeth

A wate r efficient s hower rose

Don't leave tap running w hen brushing teeth

Have less showers/share s hower s/share baths

Shower ti mer/a

A AAA rated or greater front loading washing Alling of flow limiters and tap aerators

I have always saved wate r

Flush toilets less

Alling of flow limiter s and tap aerators A AAA rated or greater front loading washing

Figure 3. Water Savi ng s Practices. To date, what are all of the individual things your household has done in order to save water? Top 10 responses. rhe environmental credentials of the developments, although they could identify ranks (41 %) and/or dual reticulation (56%) as unique feature of their estates, with considerably fewer volunteering WSUD landscaping practices or specific stormwater controls such as sedimentation basins native plants and sand fi lters. T he potential of dual supply to reduce the demand on drinki ng water was recognised significantly more often by residents with both a tank and dual supply (95%) compared to those without a tank (68%).This suggests that the presence of the mandatory tank heightened water awareness. However environmental benefits such as reducing the flow of waste water into rivers and reducing greenho use em issions from water infras tructure were nominated at low levels (17%), but significantly more frequent, levels by those with d ual supply bur no tank (5%) . Overwhelmingly the residents were comfortable with using recycled water for gardening, outdoor uses and toilet flu shing. T his is consistent with ocher studies in Australia (AC Neilsen 2005, Brown and Davies 2006). Opinion was d ivided, however, as 12% strongly agreed rhar they

Journal of the Australian Water Association

did not like the idea of using recycled water on their gardens and 14% d id not want to use it for car washing. Surprisingly, more of the residents with both dual supply and a rainwater tank envisaged using the recycled water for laundry use (22% as compared to 15% of those without a tank), and 8% of those without tanks considered rhe recycled water ap propriate for topping up the pool altho ugh this is forb idden by the Gold Coast City Council. T he assumption that this is appropriate may be reinforced by the interim measure of providing potable supply through the purple pipes. The recycled water is not intended to be used for purposes involving direct contact yet a small but significant number of residents nominated showering (5%) or pool fillin g (8%) as acceptable uses of the recycled supply.

Maintaining Trust and Goodwill with Dual Supply Systems The Pimpama-Coomera recycled water will be supplied at a class A+ standard and rigorous monitoring and testing regimes are required to ensure its puriry however there is a possibility of unforseen aesthetic

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problems (Pimpama Coomera Alliance 2007). A study of residents experience with recycled water in Newhaven in Adelaide fou nd chat many residents were dissatisfied with the q uality of water for toilet fl ushing, specifically with odour, colour and tu rbidity (Marks et al. 2003). The develop ment and maintenance of cruse is a critical issue in pro moti ng the acceptance and ap propriate use of recycled water supplies. Marks (2004) listed a set of conditio ns for the development of cruse in recycled water for non-potable uses. Sh e estab lished chat developing trust is an ongoing social process subject to renewal and revisio n. Residents will confirm or revise their crust in recycled water depending on their experien ces with the water, social cues (such as what the neighbour does) and social and legal structures chat enforce standards and pro mote the hab ituation of compliance, amo ngst ocher factors. O n ly 5 of the I 02 respondents with dual supply disagreed with any of the three direct questions abou t cruse. Ap proximately half reported a level of cruse of9 or 10 (out of I O) in the technology, the authorities' ability co ensure safety and the suicabilicy of che standard of che recycled water. When asked about the d isadvantages of d ual supply two thirds of respondents said there were none, although around 20% nom inated an eco no mic answer such as the cost to install o r unkn own costs and 11 % of chose without a tank nominated the danger of accidental ingestio n. T his trust transcend s knowledge as demo nstrated by the gap berween chose residen cs who report a good understanding of how their dual system fu nctions (34% rate themselves 9 or 10 ou t of IO) and chose reporting none to liccle (35% race their knowledge 4 or less). This suggests cruse in au tho rity has been rein forced by both the clear design protocols and demonstrated social and organisational accep tance. This may result in worse o utcomes in the event of teething problems with the new system u nless clear and consistent communication and regulatio n strategies are in place. A common perception is chat water availab le through a dual reticu lated supply is somehow free of use limitations. Residents with dual supply are far less likely than ocher groups co engage in ho usehold grey water recycling and over 30% did not see a link to potable water consumption. Only 30 % of greenfield residents have run greywacer hoses out o f the house, whereas 50% of tank recrofitters do so. Comments indicate chat residents of suburbs with dual supplies do not consider it necessary co install a rainwater tank as they expect the

a Reeycled (proposed use)

a Tank water (actu al use)

I Bathroom Kitchen Washing machine (cold)

Garden Toilet 0%

10'/4

20'!.

30'.4

40'.4

50%

60%

70% 80%

90% 100 Âž

Figure 4. Uses of ta nk water and recycled supply by households with both (N=37). Wh at does your household use the tonk water for? What will you use the d ual reticulated wa ter for? dual supply to provide su fficient water for all their requirements. Residents with both rainwater tanks and recycled water appear not to have a clear understanding of how to

use the rank water (Figure 4). Tan ks and d ual supply com pete as supplements to p otable water fo r the household er and strategies wi ll be needed to p romote the use

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Journal of the Australian Water Association

QUALITY ENDORSED COMPANY AS/NZS ISO 9001 STANDARDS AUSTRALIA Licence no: 1628

water

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d ,e c ,e ntralised s ~ of rank if recycled water is not to be used for hot water and laundry. Greenfield residents generally report char they do not save water for dry periods nor do they know what volumes remain in their tanks and this is reflected in their tendency nor to carry our general maintenance. They were significantly more likely to believe that rank water is not safe to drink. In contrast, peri-urban residents expressed strong belief in the safety of rainwater, while retrofi rrers as a group ftr between these viewpoints.

Information Different informatio n chan nels reach each of these groups. Periurban residents access technical info rmation from suppl iers. Retrofoters access a much broader spectrum of information sources including local council, frie nds and fa mily, medi a stories, websites and retailers. Few greenfield residents report having sought info rmation about their dual reticulation systems and those chat have received information did so via the developer (37%) or the local council (20%), although the majority said they would go to the council if they wanted more information (66%).

Conclusions The motivacion for insralli ng a rain water tank was quire diffe rent for che three cohorts: peri-urban residents require che water to live in their area, retrofttters are supplementing town water for purposes usually restricted during droughc and greenfield residents have a rank as part of the building development process and are discovering how to use the water. Urban retirees are less concerned with reducing their demand for parable water chan supplementing restricted supplies. Greenfield fam ilies, on the other han d, have readily accepted a range of alternative praccices imposed as cond itions of living in the subdivision, and are less likely to judge their water saving activities as sufficient already. A number of factors may contribute to this, such as the shorter tenure in their homes means practices are more flexible, the younger age group has assimilated more environmental responsible values, and the social modell ing of behaviour with in new esrates reinforces and validates new practices. What is not apparent is that knowledge of the water sensitive features of estates, or the technology of water treatment was necessary for the acceptance of new practices by greenfield residents. The fli p side is that knowledge levels for managing home water ranks or dual supply were also lacking. In spite of this there was pride in the

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environmental cred ibi lity of estates and a reported feel ing that they could personally be doing more to help. Th is group appeared to be very receptive to educational strategies, even though chey reported little effort in seeking information themselves. Rebates, educatio n and developme nt regulation have effectively promoted the installation of rainwater ranks. T here is now a clear need for management scracegies to address the effective use and mai ntenance of rainwater ranks and promote the addition of plumbing connections for internal household uses. Scracegies for improving maincenance practices will need to be actively dissem inated, perhaps as fact sheets or fo llow up mail outs to rebate recipients. A seco ndary rebace scheme to subsidise the con nection of existing urban tank to toilets or laund ry is nor likely to succeed with recrofirrers who would avoid the imposition of any restrictions on their tank water use, but may be more effective in greenfield estates.

Acknowledgments The community research and prelim inary analysis, including the graphs presented here, was undertaken by Enhance Management. Dr Petra Skoien ofN RW Qld designed the survey instrument.

AC Neilsen (2005). Imegrated water management research. Report prepared for the Brisbane City Council. Brown, R. (2004). Local institutional development and organizational change for advancing sustainable urban water futures. Keynote Address in Proceedings of the International Conference on Water Sensitive Urban Design: Cities as Catchments, 21st25th November 2004, Adelaide, Australia. Brown R. and Davies P. (2006) Understanding community receptivity to water re-use, In 7UMD & 4WSUD Book of Proceedings (Vol 1) Eds, Deletic A. and Fletcher T . 119126 Enhance Management (2007) SEQ Householders Attitudes Toward and Experiences with Decentralised Water Supply Systems, report prepared for Natural Resources and Water, Queensland Government to

Livingston, D., Ashbolr, N., & Colebatch, H. (2006). Institutional barriers to decentralized systems. Water, 33(3), 75-77 Marks, J.S ., Cromar, N., Fallowfield, H., Oemcke, D. & Zadoroznyj, M. (2003). Community experience and perceptions of water reuse. Water Science and Technology: Water Supply, 3(3), 9- 16.

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d[ p

Marks, J.S. (2004). Advancing community acceptance of reclaimed water. Water 31 (5), 46-51. Nancarrow B., Smith, L., and Syme, G.J . (1996-7) The ways people chink about water journal ofEnvironmental Systems 25(1), 15-27 Pimpama Coomera Alliance, Recycled Water in Pimpama Coomera, Fact sheet 5, Gold Coast Waterfurure, http://www.goldcoasr.qld. gov.au/ attachment/goldcoastwater/ PC_FS5_recycledwater.pdf Po, M., Nancarrow, B.E., Leviston, Z., Porter, N.B., Syme, G.J . & Kaercher, J.D. (2005). Predicting Community Behaviour in Relation to Wastewater Reuse: What drives decisions to accept or reject? Water for a Healthy Country National Research Flagship, CSIRO Land and \~acer: Perth. Radcliffe, J.C. (2004). Water Recycli ng in Australia. Australian Academy of Technological Sciences and Engineering, Melbourne. Roseth, N . (2006) Community Views of Water Shortages and Conservation, CRC for Water Quality and Treatment, Research Report No 28, www.watercenrre.org/ resources/ ResourcesLibrary/CRC%20Reporr28_ Corn m unity_ views_water_shortages. pdf/ download Russell, S. (2002). \~acer recycling as a sociotechnical system: contributions from technology studies to analysis and intervention. lnviced paper co workshop Integrated Concepts for Advancing Sustainable Urban Water Management: Developing Interdisciplinary Research Agendas for Total Water Cycle Management, Wollongong.

References

Hurlimann, A. & McKay, J. (2004) Attitudes reclaimed water for domestic use: Parr 2. Trust. Water 31 (5), 40-45.

Russell, S. (2004). Beyond 'impacts' and 'obstacles': a wider role for social analysis in water reuse. Paper to workshop OzAQUAREC VI: A Triple Bottom Line Approach to \Irater Recycling, Wollongong. Queensland Government, (2006). Water-savings targets mandatory for new homes from January l: Fraser. Ministerial Media Statements. Brisbane: Queensland Government. http:/ /stacements.cabinet. qld.gov.au/MMS/StatementDisplaySingle. aspx?id=49661. Accessed l 0/0 l /2007 Queensland Government (2007a), Development Code 25, MP 4.2 Water Savings Targets, h crp:/ /www.lgp.qld.gov.au/ docs/bu ii ding__codes/queensland_developmenc_code/d rafr/QDC_Part25_drafr_2.pdf Queensland Government (2007b) Home Waterwise Rebate Scheme: rainwater ranks brochure, http://www.nrw.qld.gov.au/ water/saverscheme/pd f/ rainwacer_tanks .pdf, 13/3/07

The Authors Anne Gardiner, Petra Skoien and Ted Gardner all work for the Queensland Department of Natural Resources and Water. Anne is a Senior Natural Reso urce O fficer working in Community and In cegration Sciences (anne.gard iner@nrw. qld.gov.au).

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ALTERNATIVE INDICATORS FOR DETECTION AND QUANTIFICATION OF FAECAL POLLUTION W Ahmed, A Goonetilleke, T Gardner Abstract T raditional faecal indicator bacteria such as faecal coli forms, Escherichia coli and enterococci have long been used as indicators of faecal pollution in enviro nmental waters. However, the reliability of these traditional indi cators has been questioned in terms of their ability to pred ict the likely presence of path ogens. Another limitation of these ind icators is that they cannot be used co distinguish the sources of faecal pollution which need to be known to ensure the improved management of water quality and the assessment of health risk. fn recent years, the use of alternative microbial faecal indicators such as faecal anaerobes (i.e. Bacteroides spp., Bifidobacterium spp., Clostridium perfringens), and viruses (phage), and chemical indicators (i.e. faecal sterols, caffein e, and optical brighteners) has become popu lar because these can provide sensitive and accurate measurement of faecal poll ution in environmental waters. In this paper, the advantages and limitations of using alternative indicators fo r predicting the sources of faecal pollution are briefl y evaluated. The correlations between alternative indicators and pathogens in environmental waters are discussed. A combination of traditional indicators along with alternative indicators and markers is suggested for monitoring faecal pollution, and future research directions for direct pathogen monitoring are also discussed.

Introduction Coastal an d inland waters are commonly polluted by pathogenic mi croorganisms, particularly following heavy rainfall. Nonpoi nt sources such as domestic and wild anima ls, p oo rl y perfo r min g on-site wastewater t reatment systems, u rb an stormwater runoff, and point sources such as industrial effluents and raw sewage are known to be potential sources of such pollution. Traditional faecal indicator bacteria such as faecal coliforms, E. coli and enterococci have long been used to assess the microbiological quality of environmental

waters, bu t do not distinguish between sources. T he public health risk from humanassociated faecal po llu tion is well recogn ised and the risk is co nsidered to be greater than fro m anim al-derived faeca l poll ution (Field & Samadpour 2007). However, pathogens such as Escherichia coli O l 57:H7, Salmonella, Campylobacter jejuni, Giardia sp p ., Cryptosporidium spp., and hepatitis E viruses ca n also be spread via animal faecal poll11tion (Craun et al. 2004). Direct monitoring of pathogens in environmental waters is an attractive option as ir can provide valuable informa tion regarding public health risk. However, there are hundreds of different types of pathogens chat can be found in water, and therefore it is not an economically, technologica lly or practically feasible option fo r th e routine monitoring of water quality. Epidemiological studies have established human health standards based on exposure to faecal ind icator bacteria (Pruss et al. 1998) . However, the ideal faecal indicator bacteria should satisfy a number of specific criteria. They should be universally native to the intestine of warm-blooded animals, should nor be pathogenic, their conce ntration should be higher than pathogens, they should not mul tiply outside the host and they should be resistant to a variety of environmental stresses. Finally, ideal indicator bacteria should have a strong association with the presence of pathogens. T he shortcomings of the traditional indicators in relation to these have been common ly reported in the li terature. These include the following: • may originate from non-faecal sources (Scott et al. 2002); • ability to replicate in environmental waters in tropical regions (Desmarais et al. 2002); • susceptible to the disinfection process (Hurst et al. 2002); • cannot be used to differe ntiate the sources of faecal poll ution (Field and Samadpour 2007); and

human from animal pollution. .1.Jutn1guts1J111g

• weak association with the presence of pathogens (Horman et al. 2004). In recent years, phenotypic and genotypic microbial source tracking (MST) meth ods have been developed to distinguish various sources of human and animal faecal pollu tion in surface waters (Scott et al. 2002). The most commonly used methods such as antibiotic resistance ana lysis (ARA), biochemical finge rprinting (BF), ribotyping, repetitive extragenic palindromic (rep) PCR require the development of a known source database of traditional indicators (i .e. E. coli and enterococci) from host groups, based on the hypothesis chat phenotypic or ge notypic characteristics of specific bacteri al strains are associated with specific ani m als. The developed database is then used to compare fingerprints fro m these same indicator bacteria found in environmental waters (Field and Samadpour 2007). Despite the successful application of these database-dependent methods, several questions have arisen regarding t heir utility. For instance, the size and the representativeness of the database need co be add ressed prior to developing a database for optimal performance. It has further been reported that tern poral and geographical variability ex ists in faecal indicators, which may restrict their use for a un iversal database. In response to these facto rs, it has been suggested chat a specific database should be developed for each catchment of interest (Wiggi ns et al. 2003). This approach, however, is unlikely to be cost effective and for this reason may nor become an accepted monitoring tool for regulatory authorities. Some of these limitations of MST using£. coli and enterococci could be partly overcome by usi ng alternative faecal indicators such as faecal anaerobes (Bernhard & Field 2000), viruses (Borrego et al. 1987) and faecal organic compounds (Leeming & N ichols 1996). The most important feature with alternative indicators is that most of them could be used to distinguish the sources of faecal pollution without the need for developing a database. Therefore, better

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Figure 1. Commonly used alternative indicators of faecal pollution. management practices can be implemented to minimise the potential health risk associated with faecal pollution. The use of some of these alternative indicators is gaining popularity as evidenced by a recent special issue of Water Research (volume 41, issue 16, 2007) which focused on faecal source tracking (FST) methods and their application. Of the 24 research papers, 13 reported the use of alternative indicators alone or in combination with traditional indicators. T he purpose of this review is to evaluate rhe ad vantages and limitations of alternative indicators for their ability to predict the sources of faecal pollutio n. The correlation between alternative faecal indicators with pathogens is also discussed. Furthermore, current methodologies for direct monitoring of pathogens in environmental waters and future research directions are discussed.

Alternative Indicators The most commonly used alternative indicators are listed in Figure 1. The advantages and limitations of these indicators are d iscussed below.

1. Bacteroides spp. The members of the Bacteroides genus hold promise as alternative indicators of faecal pollution due to a number of advantages including their short survival rates outside the hosts, their exclusivity to the gut of warm-blooded animals and the fact that they constitute a relatively larger portion (i.e. 1,000 fold) of faecal bacteria compared to traditional indicators (Sghir et al. 2000). However, the use of these anaerobes fo r water quality monitoring has been limited because of the difficulties in

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growing them using traditional culture methods. Nevertheless, recent advances in PCR tech nology can result in rapid detection and identification of these microorganisms (Field & Samadpour 2007). A recent study reported the identification of human and bovine specific Bacteroides-Prevotella 16S rRNA gene markers by using PCR, and concluded that these markers can be considered as potential faecal indicators to detect human or bovine origin faecal pollution (Bernhard & Field 2000) . Due to these advantages, P CR detection of Bacteroides markers has emerged as a potential tool for MST, and field studies have been conducted in the USA (Bernhard & Field 2000), France (Gourmelon et al. 2007), UK, Portugal, Ireland (Gawler et al. 2007), Belgium (Seurinck et al. 2006), Japan (Okabe et al. 2006), Austria (Reischer et al. 2006) and Australia (Ahmed et al. 2007). Consequently, real-time PC R methods have also been developed to quantify the h uman-specific Bacteroides markers in environmental samples (Okabe et al. 2006; Seurinck et al. 2006). Such an assay would provide precise information regarding the extent of sewage pollution in environmental waters. A limitation of the Bacteroides markers is that geographical specificity must be assessed prior to application because horizontal transfer of faecal bacteria is possible amongst species in close contact such as humans and dogs (Dick et al. 2005).

2. Bifidobacterium spp. Bi.fidobacterium spp. are an obligate anaerobic, non-spore-forming enteric bacteria, which are abundant in human

Journal of the Australian Water Association

faeces and rarely fou nd in animals (Bonjoch et al. 2004). As such, this group of bacteria can be considered as a potential faecal indicator to identify human faecal pollution. T he key advantage of Bi.fidobacterium spp. is that they do not replicate outside of the digestive tract due to strict growth requirements, and therefore provide evidence of recent faecal pollution. H owever, the use of these organisms for routine monitori ng of water quality is also limited due to the difficulty in growing them using traditional culture methods. I t has been reported that certain Bi.fidobacterium spp. are host-specific (Bonjoch et al. 2004). PCR and real-time PCR assays have been developed to detect and quantify these host-specific Bi.fidobacterium spp. for environmental samples (Bonjoch et al. 2004). An important characteristic of these bacteria is their limited persistency as the numbers can decrease by 3 to 4 orders of magnitude within 2 weeks in the environment. In addition, high background levels of predators and gram-positive bacteria can prevent growth and/or detection of Bi.fidobacterium spp. (Rhodes & Kator 1999). Little is known regarding the persistence and geographical d istribution of Bi.fidobacterium markers.

3. Clostridium perfringens C. perfringens are gram-positive sporeforming sulphite-reducing, anaerobic bacteria which are commonly found in the gut of warm-blooded animals. The advantage of using this bacterium is that unlike traditional indicators, they do not replicate in natural waters due to their strict growth requirements (Davies et al. 1995). C. perfringens are extremely

resistant to d isinfection processes and environmental stresses as most of the populations form spores. As such, they persist longer in the environment than traditional faecal indicators and pathogens. Consequently, these microorganisms have been suggested as an indicator for the inactivation and removal of viruses in drinking water treatment (Payment & Franco 1993). Ir has been reported that the presence of C. perfringens significantly correlates with the presence of pathogens in environmental waters (Ferguson 1996). A li mitation of C. perfringens is that they may not be sui table fo r identifying recent faecal poll ution because their persistence results in detection long after the pollution event (Desmarais et al. 2002). Similar to many alternative faecal indicators, C. perfringens standards have not yet been evaluated based on epidemiological studies in relation to the acceptable risk associated with faecal pollution.

4. Bacteroides fragilis bacteriophage

B. ftagilis is an anaerobic gram-negative rod-shaped bacterium present in high numbers in both humans and animals. The phages which infect B. ftagilis have been proposed as an indicator for human faecal pollution. B. ftagifis HSP 40 strain has been found in human samples but not detected in samples fro m animals (Tartera & Jofre 1987). For this reason B. ftagifis bacteriophage is considered as a poten tial candidate for human faecal pollution tracking in surface waters. The key advantage of using Bifidobacterium spp. is that they do nor replicate in the environment. In addition, their presence in the environment has been found to significantly correlate with the presence of human enteric viruses Oofre et al. 1989). However, these phages do nor occur commonly in some geographical areas including the USA and Canada (Scott et al. 2002). Additionally, the difficulty in recovering this phage from waters wich low levels of faecal pollution limits the use of this organism as a faecal indicator. 5. F+ RNA coliphage Coliphages are viruses chat infect E. coli. It has been reported that animal and human faeces contain different serotypes of RNA coliphages, and therefo re can be used to identify the sources of faecal pollution (Cole et al. 2003). The F+ RNA coliphages comprise of 4 sub groups namely I, II, III and IV. Members of group I are commonly found in both humans and animals, while group IV is associated only with animals. However, members from group II and III have been found to be associated with sewage. One important featu re of phages is that their physical characteristics and genetic makeup are similar to human enteric vi ruses. As such, coliphages have been considered as an index of viral pollutio n. Another notable feature is that coliphages exhibit high resistan ce to che water purification process. Hence, they are valuable indicators for viral inactivation by both UV and chemical disinfectants (Tree et al. 2003) . It has been reported that coliphages are relatively sensitive to high temperature and sunligh t inactivation in seawater (Chung & Sobsey 1993) . Nonetheless, coliphages exhibit much better resistance in freshwater systems where they could be considered as a potential indicator of enteric viruses (Sin ton et al. 2002). Overall, fu rther research into the d ifferential survival characteristics and genetic characterisation of the various groups of coliphage is warran ted.

6. Host-specific viruses Over 100 different enteric viruses are found in the in tesrine of humans. Because of their h igh degree of host-specificity they could be regarded as excellent indicators of human faeca l pollution. One major limitation is that many of them are not detectable using conventional cell culture techniques (Arraj et al. 2005). Furthermore, cell culture assays are laborious, time-consuming and

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decentralised s ~ lack sensitivity for unequivocal detection of viruses (Baggi eta!. 200 1) . H owever, PCRbased methods have been developed co detect human-s pecific adenoviruses, polyomavirnses, and enceroviruses Oiang 2002; McQuaig et al. 2006) in environmental waters. Bovine enceroviruses and porcine adenovirnses have also been proposed for che detection of animal faecal pollution. Addit ional viral targets could also be hose-specific, but molecular assays are not available at chis stage. O ne important feature of virns detection is chat they are not only hose-specific but also indicate public h ealth risk. One limitation of hose-specific viruses is char their concentration is low in receiving waters. Therefore a large volume of water need co be processed for detection.

7. Faecal sterols Faecal srerols and scanols have also been used widely as alternative indicators of faecal po llu tion (Leeming et al. 1996; Shah et al. 2007a). Coproscanol is the m ajor srerol (comprising about 40-60% of the total scerol content) in human faeces and is considered a biomarker of human faecal pollution (Leeming et al. 1994). H owever, the use of coproscanol alone as a biomarker can lead to a false indication of results as it is also present in the faeces of ocher animals such as pigs (Leeming et al. 1996). In addition, sm all amounts can be generated from cholesterol in anaerobic sed iments (Mudge et al. 1999). As such, the ratio of coprosranol with other faecal sterols has been proposed as an imp roved method to identi fy the sources of human/animal faeca l pollution (Leeming 1997). In recent studies, ratios across a range of C27:C29 scerols and 5~:5a scanols have given a m ore specific measure of pollution (Bull et al., 2003; Leeming et al., 1996). When C27:C29 and 5~:5a ratios are both greater than 1, the faecal source is likely to be of human origin. Ratios C27:C29 and 5~:5a) < l , are indicative o f mixed faecal pollution and C27:C29 <l and 5~:5a > 1 ratios are indicative of herb ivore faeca l pollution. H owever, a recent study reported the poor performance of faeca l scerols in determining the percentage contribution of sources in mixed faecal samples (Shah et al. 20076). In addition , no direct relationship has been established between the p resence of faecal scerols and pathogenic organism s or consequent health risks.

8. Caffeine Caffeine is of anthropogenic origin, and is fou nd in beverages and m any pharmaceutical produces. I r is excreted in rhe urine o f individuals who have

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consumed ir. Because of this, ir has been suggested chat the presence of caffeine in che environment could indicate rhe presence of human sewage (Burkhardt 1999). Levels of caffe ine in domestic wastewater have b een reported to be between 20 to 300 Âľg/L (Roger et al. 1986). As such , dilution of m ore than 1:200 would make it difficult to detect in environmental waters. Little is known about the fate of the caffe ine in the environment (Sta ndley et al. 2000). Fu rtherm ore, si milar co faecal scerols, no direct relationship has been established between the presence of caffeine and pathogenic microorganisms.

9. Optical brighteners Optical brighteners have been suggested as potential indicators to d etect the presence or absence of human faecal pollution in environmental waters. Optical brigh reners (also known as flu orescent whi ten ing agents) are white dyes, a common component of laundry detergents, wh ich act to make light colours appear brighter (Kaschig 2003). Laundry effl uent is a major co mponent of human wastewater as plumbing system s collect wastewater from both toilets and washing machines. Because o f this, optical brighteners serve as indicators of the p resence of sewage in environmental waters. Optical brighteners in environmental waters could be detected using several methods such as 1) leaving a cotton pad in environmental waters followed by detection using exposure to UV light, 2) high performance liquid chromatography (HPLC) detection, and 3) flu oromerry d etection. The combination of flu orometry detection and bacterial cou nts were successful in determining rhe sources o f faecal pollution (H agedorn et al. 2005). H owever, one major disadvantage of optical brighteners is the lack of specificity as background fluorescence can originate from various organic compounds (Gregor et al. 2002) . A recent study reported high fluoromecric value in areas with no faecal pollution (Harrel et al. 2008) .

Correlation Between Alternative Indicators and Pathogens The correlation between indicator bacteria (both traditional and alternative indicators) and pathogenic microorganisms is one of rhe m ost important issues in risk assessm ent. Lierle is known regarding th e correlation between faecal anaerobes (i .e. Bacteroides spp. and Biofidobacterium spp.) and pathogens. A recent study found a positive correlatio n between general Bacteroides spp. and zoonoric pathogens (Walters et al. 2007) . In the sam e study,

Journal of the Australian Water Association

rumi nant-specific markers were also found to predict the presence of E.coli O157:H7 and Salmonella while the human specific markers predicted the presence of Campylobactel' spp. Anorher recent study in California reported a moderate correlation between the presence of h uman-specific Bacteroides marker and human-specific polyomaviruses in surface waters (M cQuaig et al. 2006) . Human-specific Bacteroides markers were also found to show significant correlation with E. coli 0157 and Salmonella sp p. (Olga et al. 2007). Davies et al. (1995) reported a significant co rrelation between C. perfringens and rhe occurrence of pathogens in surface waters. Signifi cant correlation was also observed between the presence of C. perfringens and Salmonella spp. in fr esh and marine waters. Positive correlation between bacteriophage, enreric virnses and ocher pathogens have been demonstrated for marine waters by Rozen and Belkin (200 1). However, co dare there have been no published data on rhe correlation between chemical indicators/organic compou nds and pathogens.

Molecular Methods for Direct Monitoring of Pathogens The detection and enumeratio n of rradirional indicators and pathogens using conventional cultu re and biochemical methods have some major limitations such as underestimation of rhe bacterial co ncentration due to injured or stressed cells. Furthermore, certain microorganisms in environmental waters co uld b e viable but cannot b e cultured using conventional culture techniques. In addition, some of rhe rest methods are time consuming and labour intensive. H owever, rhe application of PCR-based methods has generated interest in direct monitoring of pathogens in environmental waters. The advantages of PC R-based m ethod are chat they are rapid and can detect organisms char are difficult to grow using conventional tech niques . PCR-based methods have been used to detect a wide array of pathogenic microorganism s in environ mental waters (Olga & Okabe 2006) . Multip lex PCR methods have been developed which are able co target multiple pathogens in a single tube; as have realtim e PCR methods, which are able co quantify target genes in environ mental waters. A major drawback of PCR-based methods is their inability co distinguish between viable and non-viable organism s si nce the DNA of both live and d ead cells could potentially be amplified in a reactio n. However, reverse transcriptase (RT) PC R can be used co detect viable cells

Iecnn1ca1 reatures fo reed paper

only (Yaron 2002). RT is an enzyme able co synthesise single-stranded DNA from RNA which gives sensitive resu lts without a pre-enrichment seep (Deisi ngh 2004). To increase the sensitivity and specificity of che dececcion, PCR may also be used in conjunction with ocher techniques such as the most probable number counting method (M PN-PCR) (Rose et al. 1997), PCR enzyme-linked immunosorbenc assay (PCR-ELISA) (Sails et al. 2002) or the fluorescence in situ hybridisation (FIS H) technique (Moreno et al. 2003) . The immunology-based methods such as ELISA (Crowther 1995) and immunomagnecic separation (IMS) (Mine 1997) provide sensitive detection of a wi de range of targets. ELISA co mbi nes the specificity of antibodies and the sensicivicy of si mple enzyme assays by using antibodies and antigens. l MS is a pre-concentration

technique which can be used co cap ture and extract che targeted pathogen from bacterial suspension by using antibody coated magnetic beads. Microarrays are increasingly being used in pathogen detection. T his method was developed for srudies of gene expression and regulation in organisms for which che complete genome sequence is known (Kaeo-Maeda et al. 2001) . Arrays exist for the dececcion of several viru lence factors for E. coli 0 l 57:H7 and Shigelfa spp. and application of these suggests that virulence factors may be useful in che automated identification and characterisation of bacterial pathogens (Chizh ikov et al. 2001).

Conclusions The use of alternative faecal indicaror bacteria appears co be promising for distinguishing between the sources of

human an d animal faecal pollution in environmental waters. A tabulation of advantages and limitations is given in Table I. However, srudies reporting the correlation between these al ternative indicators and pathogens are limited and warrant further invescigacion. None of rhe cradicional and/or alternative indicator bacteria can be seen as a 'gold standard' in rerms of predicting the presence of pathogenic bacteria, viruses and protozoans. However, a combination of rradicional indicators along with alcernacive indicators and markers could provide valuable information regardi ng the extent of faecal pollution, its origin and possib le correlation with pathogens. Th is approach has been applied in only a few studies (for example Boehm et al. 2003; Horman et al. 2004; Simpson et al. 2004). le has bee n reported char traditional indicators and a lternative

Table 1. Advantages and limitations of alternative indicators of faecal pollution. Alternative indicators Bacteroides spp.

Advantages

Limitations

1. Certain species ore host-specific.

1. Little is know about the relationship with pathogens.

2. Indicate recent faecal pollution.

2. Difficulty in g rowing using traditional meth ods.

3. Do not replicate in the environment. 4. PCR-bosed rapid detection .

Bifidobacferium spp.

1. Certain species ore host-specific.

l. little is know about the relationship with pathogens.

2. Do not replicate in the environment.

2. Limited persistency. 3. Low sensitivi ty of detection methods.

Closfridium perfringens

1. Do not replicate in the environment.

1. Do not exh ibit host-specificity.

2. Highly resistant to environmenta l stress.

2. Indicate post faecol pollution. 3. Labour-intensive.

Bacteroides frogilis phage

F+ RNA coliphoge

1 . Human-specific.

1. Present in low concentration.

2. Do not replicate in the environment.

2. little is known about the relationship w ith pathogens.

3. Good correlation with enteric viruses.

3. Variable persistency.

1. Human-specific.

l. Do not present in all geographical areas.

2. Do not replicate in the environment.

2. Variable persistency.

3. Good correlation wi th enteric viruses.

3. Warrants more genetic characterisation.

4. Highly resistant to disinfection process. Host-specific viruses

1. Human and bovine specific.

1. Present in low concentration

2. Highly resistant to d isinfection process

2. Con be absent in the presence of faecal pollution.

3. PCR-bosed rapid detection.

3. Concentration and purification of viral nuc I eic acid from environmental samples con be difficult.

Foecol sterols

l . Con be used to distinguish between human and animal sources.

1. Expensive analytical techniques. 2. Indicate post faecal pollution. 3. No direct relationship with pathogens. 4 . Low sensitivity of detection methods. 5. labour-intensive.

Caffeine

l . Indicate the presence of human faecal pollution.

1. Low sensitivity of detection methods. 2. No direct relationship with pathogens.

Optical brighteners

l . Indicate the presence of human sewage

1. Low sensitiv ity of detection method

2. Inexpensive

2. Locks specificity. 3. Can yield false positive. 4. No direct relationship with pathogens.

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decentralised s ~ indicators showed sign ifica nt crosscorrelation with each other as well as significant co rrelations with enreropathogens in surface waters (Horman et al. 2004). Since the correlation between indicators and the presence of pathogens in waters is co ntroversial, the best app roach could be direct m onitoring of pathogens (where possible) so char p ublic health risk co uld be assessed. The recent advances in PCR, immunology-based methods and microarray technologies will not only allow sensitive and specific detection of pathogens, but also will enable detection o f multip le targets with a single assay and wou ld provide important information on microbial water quality and consequent h ealth risk.

The Authors Dr Warish Ahmed has had a career in identifyi ng the sources of faeca l pollution in environmental waters. H e is curren tly working as a water microbiologist at the Queensland Department of Narural Resources and Water and Queensland University of Tech nology. Email: warish.ahmed@nrm.qld.gov.au. Professor Ashantha Goonetilleke is a professor in water/environmental engineering at Q ueen sland U niversity of Tech nology. Ted Gardner is Principal Scientist with th e Q ueensland D epartment of Natural Resources and Water and an adjunct professo r at Q ueensland U niversity of Techn ology.

References Ahmed, W ., Stewart, J. , Powell, D . & Gardner, T. 2007, 'Evaluation of Bacteroides markers for the detection of human faecal pollution' , Letters in Applied Microbiology, doi : 10. I 11 l/j. 1472-765X.2007.02287.x Arraj, A., Bohatier, J., Laveran, H. & Traore, 0 . 2005, 'Comparison of bacteriophage and enreric virus removal in pilot scale activated sludge plants', journal ofApplied Microbiology, 98, pp. 516-24. Baggi, F. , Demarca, A. & Peduzzi, R. 2001, ' Persistence of viral pathogens and bacteriophages during sewage treatment: lack of correlation with indicator bacteria', Research in Microbiology, 152, pp. 743-51. Bernhard, A.E. & Field, K.G. 2000, 'A PCR assay co discriminate human and ruminant faeces on the basis of host differences in BacteroidesPrevotella genes encoding l 6S rRNA', Applied and Environmental Microbiology, 66, pp. 4571-4. Bonjoch, X., Balleste, E. & Blanch, A. R. 2004, ' Multiplex PCR with 16S rRNA gene targeted primers of Bifidobacterium spp. to identify sources of faecal pollution', Applied and Environmental Microbiology, 70, pp. 3171-5. Boehm, A.B., Fuhrman, J .A., Morse, R.D . and Grant, S.B. 2003, 'Tiered approach for identification of a human faecal pollution source at a recreational beach: a case study at Avalon Bay, Catalina Island, California',

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Environmental Science and Technology, 37, pp. 673-80. Borrego, J.J., Morinigo, M.A., de Vicente, A., Cornax, R. & Romero, P. 1987, 'Coliphage as an indicator of faecal pollution in water, its relationship with indicator and pathogenic microorganisms', Water Research, 21, pp. 1473-80. Bull, l.D ., Elhmmali, M .M ., Roberts, D .J . and Evershed, R.P. 2003, 'The application of steroidal biomarkers co track the abandonment of a Roman wastewater course at Agora (Athens, Greece)', Archaeometry, 45, pp. I 49-61. . Burkhardt, M.R., Soliven, P.R., Werner, S.L. & Vaught, D.G. 1999, 'Determination of submicrogram per litre concentrations of caffeine in surface and groundwater samples by extraction and liquid chromatography', journal ofAOAC International, 82, pp. 161-6. Chung, H . & Sobsey, M.D. 1993, 'Comparative survival of indicator viruses and enreric viruses in seawater and sediments', Water Science and Technology, 27, pp. 425-8. Chizhikov, V., Rasooly, A., Chumakov, K. & Levy, D.D. 2001, 'Microarray analysis of microbial virulence factors', Applied and Environmental Microbiology, 67, 3258-63. Cole D ., Long, S.C. & Sobsey, M.D. 2003, ' Evaluation off+ and DNA coliphages as source-specific indicators of fecal contamination in surface waters', Applied and Environmental Microbiology, 69, pp. 6507- 14 Craun, G.F., Calderon, R.L. & Craun, M.F. 2004, In: Cotruvo, J.A., Dufour, A., Rees, G ., Bartram, J., Carr, R., Cliver, 0 .0., Craun, G.F., Fayer, R. and Gannon V.P.G (Eds.), 'Waterborne outbreaks caused by zoonotic pathogens in the USA', World H ealth Organization, IWA Publishing, London, pp. 120-135. Crowther, J.R. 1995, ' ELISA Theory and P ractice', Humana Press Inc., USA ISBN 089603-279-5 . Davies, C.M., Long, J.A.H. , Donald, M. & Ashbolt, N.J. 1995, 'Survival offecal microorganisms in marine and freshwater sed iments', Applied and Environmental Microbiology, 6 1, pp. 1888-96. Deisingh, A. K. & Thompson, M. 2004, 'Strategies for the detection of Escherichia coli 0 l 57:H7 in foods', journal ofApplied Microbiology, 96, pp. 419-29. Desmarais, T.R., Solo-Gabriele, H.M. & Palmer, C.J. 2002, 'Influence of soil on fecal indicator organisms in a tidally influenced subt ropical environment', Applied and Environmental Microbiology, 68, pp. 1165-72. Dick, L.K., Bernhard, A.E., Brodeur, T.J., Santo Domingo, J .W., Simpson, J.M. Walters, S.P. & Field, K.G. 2005, ' Host distributions of uncultivated fecal Bacteroidales bacteria reveal genetic markers for fecal source identification', Applied and Environmental Microbiology, 71, pp. 3184-91. Ferguson , C.M., Coote, B.G., Ashbolt, N .J. & Stevenson, l.M. 1996, 'Relationships between indicators, pathogens and water quality in an estuarine system', Water Research, 30, pp. 2045-54. Field, K.G . & Samadpour, M. 2007, 'Fecal source tracking, the indicator paradigm, and managing water quality', Water Research, 41, pp. 3517-38.

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Gawler, A.H., Beecher, J.E., Brandao, J., Carroll, N.M ., Fabio, L., Gourmelon, M., Masterson, B., Nines, B. et al 2007, 'Validation of hostspecific Bacteroides l 6S rRNA genes as markers to determine the origin of fecal pollution in Atlantic Rim countries of the European Union', Water Research, 41, pp. 3780-84. Gourmelon, M., Caprais, M.P., Segura, R., Mennec, C. L., Lozach, S., Piriou, J.Y. and Rince, R.A. 2007, ' Evaluation of two-libraryindependent microbial source tracking methods to identify sources of fecal contamination in French estuaries', Applied and Environmental Microbiology, 73, pp. 4857-66. Gregor, J ., Garrett, N ., Gilpin, B. , Randall, C. & Saunders, D. 2002, 'Use of classification and regression rree (CART) analysis wirh chemical faecal indicators to determine sources of conramination', New Zealand j ournal of Marine and Freshwater Research, 36, pp. 38798. H agedorn, C., Salura, M., H assall, A. & Dickerson, J. 2005, 'Fluorometric derection of optical brighteners as an indicator of human sources of water pollution: development as a source tracking methodology', Environmental Detection News, 2, pp. 1-13. Harrel, P.G., Rodgers, K., Moody, G.L., H em mings, S.N.G., Fisher, J.A. & McDonald, J.L. 2008, 'Combining targeted sampling and fl urometry to identify human feca l contamination in a freshwater creek',

journal of Water and Health, doi: 10.2 166/wh.2007.004. Hurst, C.J., Crawford, R.L., Knudsen, G.R., Mclnerney, M.J. & Stetzenbach, L. D . 2002, 'Manual of Environmental Microbiology', second ed. ASM Press, Washington, DC. Horman , A., Rimhannen-Finne, R., Maunula, L., von Bonsdorff, C.-H ., Torvela, N ., Heikinheimo, A., H anninen, M.-L. 2004, 'Campylobacter spp., Giardia spp., Cryptosporidum spp., noroviruses, and indicator organisms in surface water in southwestern Finland, 2000-200 l ', Applied and Environmental Microbiology, 70, pp. 8795. Jiang, S.C. 2002, 'Adenovirus as an index of human viral contamination: Microbial source tracking workshop', Proceedings of USEPA workshop on Microbial Source Tracking, February, Irvine, CA. Jofre, J., Blasi M., Bosch, A. & Lucena, F. 1989, 'Occurrence of Bacteriophages infecting Bacteroides fragilis and other viruses in polluted marine sediments', Water Science and Technology, 21, pp. 15-9. Kaschig, J. 2003, 'Fluorescent whitening agents (FWAs) in laundry detergents. In: Proceedings of the second Symposium on Detergents, Damascus, Syria. Karo-Maeda, M., Gao, Q. & Small, P.M. 2001, 'Microarray analysis of pathogens and their interaction with hosts', Cellular Microbiology, 3, pp. 7 13-9. Leeming, R., Ball, A., Ashbolt, N., Jones, G. & Nichols, P. 1994, ' Distinguishing between human and animal sources of faecal pollution', Chemistry in Australia, 61, pp. 434-5. Leeming, R. & Nichols, P.D. 1996, 'Concentrations of coprostanol that

lt:\.11111\.C:II

I t:c:I lU It::,

decentralised s ~ correspond to existing bacterial indicator guideline limits', Water Research, 30, pp. 2997-3006. Leeming, R. 1997, ' Use of faecal srerols and bacterial indicators ro discriminate sources of faecal pollution entering Lake Macquarie, Newcastle, NSW, CS I RO Report 96-HWC I, Report prepared for che H unter Water Corporation. McQuaig, S.M. , Scott, T.M ., H arwood, V.J., Farrah, S.R. and Lukasik, J.O . 2006, 'Detection of human-derived fecal pollut ion in environmental waters by use of a PCR-based human polyomavirus assay', Applied and Environmental Microbiology, 72, pp.7567-74. Mine, Y. I 997, 'Separation of Salmonella enteriditis from experimentally contaminated liquid eggs using a hen IgY immobilized immunomagneric separation system', journal ofAgriculture Food and Chemistry, 45, pp. 3723-7. Moreno, Y., Borella, S., Alonso, J .L., Ferrs, M .A., Hernandez, M. & H ernandez, Z. 2003, 'Specific detection of Arcobacter and campylobacter strains in water and sewage by PCR and fluorescent in sicu hybridisation', Applied and Environmental Microbiology, 69, pp. I I 8 1-6. Mudge, S.M. & Gwyn Linren, D. 1999, 'Comparison ofsrerol biomarkers for sewage with ot her measures in Victoria Harbour, B.C., Canada', Estuaries, Coastal and ShelfScience, 48, pp. 27-8. Okabe, S., Okayama, N., Savichrcheva, 0. & Ito, T. 2006, 'Quantification of host-specific Bacteroides-Prevote!La 16S rRNA generic markers for assessment of fecal pollution in freshwater', Applied Microbiology and Biotechnology, 74 , pp. 894-90 l. Olga, S. & Okabe, S. 2006, 'Alternative indicators of fecal pollution: Relations with pat hogens and conventional indicators, current methodologies for direct pathogen monitoring and fucure application perspect ives', Water Research, 40, pp. 2463-76. Olga, S., Okayama, N. & Okabe, S. 2007, ' Relationships between Bacteroides 16S rRNA generic markers and presence of bacterial enteric pathogens and conventional fecal indicators', Water Research, 41, pp. 36 15-28 . Payment, P. & Franco, E. 1993, 'Clostridium perftingens and somatic coliphages as indicators of the efficiency of drinking water treatment for viruses and protozoan cysts', Applied and Environmental Microbiology, 59, pp. 24 I 8-24.

oligonucleoride probe hybridisation', Applied and Environmental

Microbiology, 66, pp. 2263-2266. Shah, V.G ., Dunstan, R.H., Geary, P.M., Coombes, P., Robe rts, T.K. & Rorhkirch, T. 2007a, ' Bacteria.I source tracking from diverse land use catchments by srerol ratios', Water Research, 41, pp. 3667-74. Shah, V.G., Dunstan, R.H ., Geary, P.M., Coombes, P., Roberts, T.K. & Von Nagy-Felsobuki, E. 2007b, ' Evaluating potential applications of faecal srcrols in distinguishing sources of faecal contaminati on from mixed faecal samples', Water Research, 41 , pp. 3691 -700. Sinton, L.W., H all, C.H., Lynch, F.A. & Davies-Colley, R.J. 2002, 'Sunlight inactivation of fecal indicator bacteria and bacreriophages from waste stabilization pond effiuenr in fresh and saline waters', Applied and Environmental Microbiology, 68, pp. 1122-31. Standley, L.J., Kaplan, L.A. & Smith, D. 2000, 'Molecular tracer of organic matter sources to surface water resources', Environmental Science and Technology, 34, pp. 3124-30. Tarrera, C. & Jofre, J. 1987, 'Bacteriophages active against Bacteroides .fragilis sewage-polluted waters', Applied and Environmental Microbiology, 53, pp. 1632-7. Tree, J.A., Adams, M. R. & Lees, D.N. 2003, 'Chlorination of indicator bacteria and viruses in primary sewage effiuenr', Applied and Environmental Microbiology, 69, pp. 2038-43. W alters, S.P., Gannon, V. P. G. & Field, K.G. 2007, ' Detection of Bacteroides fecal indicators and the zoonotic pathogens E. coli O157:H7, Salmonella and Campylobacter in river water', Environmental Science and Technolflgy, 41 , pp. 1856-62. W iggins, B.A., Cash, P. W ., C reamer, S., Darr, S.E., Garcia, P .P., Gerecke, T.M . et al. 2003, 'Use of antibiotic resistance analysis for representat iveness resting of multi-watershed libraries', Applied and Environmental Microbiology, 69, pp. 3399-405 . Yaron, S. & Matthews, K.R. 2002, 'A reverse rranscripcase-polymerase chain reaction assay for detection of viable Escherichia coli O l 57: H 7: investigation of specific target genes', journal ofApplied Microbiology, 92, pp. 633-40.

Pruss, A. 1998, 'Review of epidem iological scudies on health effects from exposu re to recreational warer',journal ofEpidemiology, 27, pp. 1-9. Reischer, G. H., Kasper, D.C., Steinborn, R., Mach, R.L. & Farnleirner, A. H . 2006, ' Quantitative PCR method for sensitive detection of ruminant fecal pollution in freshwater and evaluation of this merhod in alpine karsric regions', Applied and Environmental Microbiology, 72, pp. 5610-4. Rhodes, M.W . & Kator, H. 1999, 'Sorbi tol-fermenring Bi fidobacreria as indicators of diffuse human faecal pollution in escuarine watersheds', Journal ofApplied Microbiology, 87, pp. 528-35 . Rogers, I. H., Birtwell, I.K. & Ksuzynski, G .M . I 986, 'Organic extracrables in municipal wastewater', Canadian journal of Water Po!Lution Research, 21, pp. 187-204. Rose, J.B., Zhou, X., G riffin, D.W. & Paul, J .H. 1997. Comparison of PCR and plaque assay for detection and enumeration of coliphage in polluted marine waters', Applied and Environmental Microbiology, 63, pp. 4564-6 . Rozen, Y. & Belkin, S. 200 I, 'Survival of enteric bacteria in seawater', FEMS Microbiology Reviews, 25, pp. 513-29. Sails, A.D., Bolton, F .J. , Fox, A.J., Wareing, D.R.A. & Greenway, D .L.A. 2002, ' Detection of Campylobacter jejuni and Campylobacter coli in Environmental waters by PCR enzyme-linked immunosorbenr assay', Applied and Environmental Microbiolflgy, 2002, pp. 13 19-24 . Scott, T.M., Rose, J.B., Jenkins, T.M., Farrah, S.R. & Lukasik, J. 2002, 'Microbial source tracking: current methodology and fucure directions', Applied and Environmental Microbiology, 68, pp. I 089-92. Seurinck, S., Verdievel, M., Verstraete, W. & Siciliano, S.D. 2006, 'Identification of human fecal pollution sources in a coastal area: a case scudy at Oosrende (Belgium)', journal of Water and Health, 4, pp. 16775. Simpson, J.M., Santo Domingo, J .W. & Reasoner, D.J. 2004, 'Assessment of equine fecal contamination: the search for alternative bacterial source tracking rargers', FEMS Microbiology Ecology, 47, pp. 65-75. Sghir, A., Gramer, G ., Suau, A., Rocher, V., Pocharr, P. & Dore, J. 2000, 'Quanrificarion of bacterial groups within human faecal flora by

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decentralised s ~

feree

pape

URINE-SEPARATION AND REUSE TRIAL C Beal, T Ga_rdner, W Ahmed, C Walto

Abstract Urine-separating toilets (UST) have been used as an effective source control measure in many pares of Europe for years. The pu rpose of UST is to separate nutrients (N, P, K) at source to avoid mixing with faecal matter. Urine separation reduces water use and nutrient discharges to sewage treatment systems and the receiving environment, and increases the potential for closi ng the nutrient loop since the stored urine can be used as a ferti liser. UST technology ranges from single and dual flush systems to dry (com posting) to ilets. This paper wi ll fi rstly provide a brief background on UST and the reuse of urine in Europe, and then describe its application to 20 homes at the Ecovillage at Currumbin.

potassium (K) excreted by humans are co ntained in the urine, its fracrion of total volumetric wastewater flow is only around I% Qohansson et al 2002) (Figure 1). By separating the urine, nutrients can be captured and used withour the intensive, expensive and time-co nsumi ng process of treatment that is rraditionally required when urine is mixed with faeces . Urine separation ca n also reduce the peak flows of am monia in sewage treatment planes (STP) by 30% and reduce the impact of sewer overflows on rhe aquatic environment (Wilsenach and Loosdrecht 2006).

DGreywater

Although up to about 80% of nitrogen (N), 50% of phosphorus (P) and 60% of

This article has been reduced from "Closing the Nutrient Loop: A Urine Separation and Reuse Trial in the Currumbin Ecovillagc, Queensland" i n Patt erson, RA a n d Jones, MJ (Eds) Innovation and Technology for O n-site Systems. Proceedings of On-site '07 Conference 25-27 September 2007. Lanfax Laboratories, Armidale ISBN 978-0-9579438-3-4

66 FEBRUARY 2008

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Closing the loop

Manufacture of nitrogenous fertilisers is energy intensive (see below). Our deposits of economically recoverable phosphate rock

• Faeces

oUrine

90% C

0 ::, .0

;

·.:: C

U1·ine collection as in No,·thern Europe: is it feasible here?

An advantage of urine separating toilets is their lower water use. Johansson et al. (2002) report abom 0.1 to 0.3 L of water is required to flush the urine. T his is a reduction of over 90% per flush co mpared with a half fl ush from a standard 3/6 dual to iler. For a so lids flus h, the vo lume ranges from 2 to 6 L.

100%

I. Background on Urine-Separation Advantages of source separation

Reduced water use

80% 70% 60%

(,J

50%

-12 gN /p/d

-1 gP /p/d

-3 gK /p/d

Nitrogen

Phosphorus

Potassium

40%

...41 I.)

30%

20%

10% 0% Wastewater flow

Figure 1. The percentage of nutrients a nd thei r dai ly excreted mass in various w astewater components (Johansson et al. 2003).

Journal of the Australian Water Association

technical features ~

are reducing, as are our sources of potassium. Experience in Europe has shown chat it is feasible co use collected urine as a concentrated fertiliser co replace at lease some of the agriculture demand.

Life cycle analyses of different removal and recovery technologies fo r nutrients indicated source-separation can be energetically more efficient than their removal ar rhe STP and their new production from natural sources (Maurer et al. 2003) . Indeed one study reporred chat removi ng more rhan 60% of urine resulrs in che STP having a net production of energy (Wilsenach and Losdrechc 2006). The specific energy requirements for denicrificacion and phosphorus precipiracion at a STP are 13 kWh/kg N and 14 kWh/kg P, respectively (Maurer et al. 2003) whilst rradicional ferti liser production requires specific energies of 13 kWh/kg N and 8 kWh/kg P (Maurer et al. 2003). In comparison the thermal reduction of urine consumes about 10 k Wh!kg N (Maurer et al. 2003) whilst Struvite production (producing available P for separate fertiliser use) from separated urine, uses only 6 kWh/kg P (Maurer et al. 2003) Health Considerations Pathogens

In healthy humans, urine is a parhogenically sterile in che bladder Qohansson et al. 2002; Kvarnscrom et al. 2006) . Freshly excreted uri ne normally contains different dermal bacteria. The most commonly observed pathogens excreted in urine of INFECTED patients are Salmonella typhi, Salmonella paratyphi, Mycobacterium tuberculosis, polyomaviruses, hepari cis B viruses and adenoviruses. If crossconcaminacion with faecal matter occurs during che use of a UST, bacteria and enteric viruses are likely co be present in the urine. However, such pathogenic microorganisms transported through urine are not considered a publ ic health risk as research on separated urine demonscrares chat storage conditions of high pH and high temperature (e.g. >20°C) for 2'.6 months will effectively render che urine solution sterile Qohansso n et al. 2002). The typical concentrations of £. coli in collected urine can reduce by > 6 log 1o within a week of storage. Considerable research has been performed in Europe on bacterial regrowth and faecal indicators (Schonning et al 2002).

although Johansson et al. (2002) suggest char the environmental risk is less than chat from traditional STPs (where discharge co waters is common). Kvarnstrom et al. (2006) also point out chat urine and fertilisers are mixed into the active topsoil, which has a microbial community comparable co that in STPs where substantial removal or inactivation of residues can occur (e.g. Watkinson et al 2007). Additionally, the residues can be retained and degraded for months in the topsoil, further reducing the likelihood of transmission into plant material via plant uptake.

•

Energy reduction

fe eed paper

Figure 2. The Gustavsberg toilet selected for the trials.

Heavy metals

Heavy metals have also been shown co be low in urine solutions from UST Qo nsson et al. 1997; Vinneras et al. 2002). Heavy metal contam ination of urine can also occur from che corrosion of metal pipes and storage tanks due co rhe high pH and high ammo nia content. Therefore standard metal should be avoided anywhere in the urine collection and transport system . Pharmaceuticals

Hormones and pharmaceuticals are excreted in urine. There is currently a knowledge gap regarding the risk of exposure from land application of urine,

Notwithstanding the above, in complex chemical mixtures such as urine, threshold values are very problematic co set and research indicates chat environmental and human toxicological effects of pharmaceuticals may be additive (Maurer et al. 2006). Lienert et al. (2007) report a > 50% removal of pharmaceuticals from the wastewater scream by separati ng urine from faeces, thereby reducing the ecorox icological risks in the aquatic environment. However, the risks from urine application co soi l for use as a fe rtiliser on food crops remain under review. II. Urine Separation and Reuse Demonstration Project Site description and project overview

T he Ecovillage at Currumbi n (the Ecovillage) is a 144 lot development on a former 110 ha grazing property in the Currumbin Valley, in the Gold Coast region of south-east Queensland

New Turbidity and Chlorine Meter from H~NN~ Hl93414

Turbidity

Features • • • • • • •

Free or Total Chlorine range - 0.00 to 5.00 mgll (ppm) Turbidity Calibration - 2. 3 or 4 point Chlorine Calibration - 1 point Turbidity Method - Ratio Nephelometric Method (90") Ught Source - Tungsten filament lamp, user replaceable Turbidity Range -0.00 to 9.99; 10.0 to 99.9; 100 to 1000 NTU auto-ranging LOG memory - 200 records, with time AND location

• Serial Interface - USB 1.1 and RS232

Tel:

+61 3 9769 0666 +61 3 9769 0699 hannains@hannainst.com.au

H~NN~

instruments

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FEBRUARY 2008 67

technical features

decentralised systems

!fereed paper

(http://www.cheecovillage. Monitoring program com.au). A core philosophy o f It is expected chat monitoring The Ecovillage is one of results collected during this sustainable livi ng where minimal project will provide a baseline impact on che environment and database fo r futu re urine maximum conservation and/or separation trials. There will be recycling o f resources is achieved. two main elements: biophysical Each house muse be constructed parameters and survey of to achieve high thermal efficiency, participant behaviour and self sufficiency in potable water, attitudes. Monitoring and partial self sufficiency in componen ts include: energy generation/use. A • Monthly collection, volume communal STP/advanced water measurement and analyses of reclamation plant treats sewage urine solution (flush water plus and reticulates Class A+ water for u rine) for N, P, K, and Figure 3. The 300 L storage bladder located under the household toilet flush ing and pathogens; house. external water use.In line with • Field and laboratory chis, a demonstration project, 3 people per household and 1.5 L u rine managed by the Q ueensland Department of experiments investigating Natural Resources and Water (DNRW), is pathogen d ie-off plus 2.5 L of fl ush water per person per day. triall ing the use of urine-separating toilets • Social survey of the behaviour and as a sustainable and achievable method of attitudes of users and the likelihood of Each bladder will be emptied monthly by a nutrient capture and water conservation pump-out truck and transferred to a 23,000 adopting the technology in the longer-term; and on-site reuse. The DNRW will manage and L polyethylene rainwater rank giving a the project with close liaison with capacity of at least 2 months urine storage • Analyses of some common developers Landmatters Currumb in Valley assuming 20 USTs at full operational pharmaceuticals and their fate in stored Pry Ltd and design engineers Bligh Tan ner capacity. During Stage I of the project un ne. Pry Ltd. There are two stages to the p roject: urine will be trucked offsite to a local STP. The first stage of the project will also STAGE I - D emonstrating the practicality Based on the lessons learnt from Swedish docu ment the practical aspects of UST such of the UST principle and STAGE II demonstration trials (e.g. Johansson et al. as plumbing challenges (wall mounted vs. Benefi cial reuse of urine. 200 2) the following points are considered fl oor mounted to ilets), blockages, odour, The objectives of the project will be to (1) in the design of the collection and storage and p umpi ng issues. storage demonstrate the advantages of separating of urine: nutrien ts such as N, P and Kat the source On-site reuse of urine • Watertight pipes and tanks and no metal for subsequent reuse as a concentrated form used for pipes and ranks in contact with T he average mass of nutrients excreted in o f fertiliser; (2) q uantify the water savings urine; the urine compared with the requirements and recovery/person of nutrients that are for grain production is presented in Table • Horizontal pipes should have a slope of achieved by UST; and (3) demonstrate to 1. T he average adult excretes sufficient 2'. 1 % as sludge continuously precipitates the urban d evelopment, local authority, and nutrients in their urine to grow enough from the urine mixture (although easy to state regulatory sectors chat urinewheat (2 00kg/year) to produce a loaf of flush away); separation and reuse can provide a safe, bread a day fo r each day o f the year. socially acceptable and sustainable • Pipes should be able to be easily There are several options for urine reuse at inspected; and alternative to trad itional wastewater the Ecovillage. T hese include land treatment management solutions. • System should not be ventilated (to application on crop area such as food crops minimise am monia loss and o dour). System selection and fru it trees, fo rage crops for mulch Odour prob lems have occurred due to poor Based on expert advice (e.g. Prof Nick supply (i. e. cue and cart); application on design and where installations are not Ashbolr, Prof Ralf Orcerpohl, Dr Hakan p u blic use land and park (i.e. landscape); watertight. In projects where the UST are J onsson), cost, cleansing capability and the use in the plant n ursery as a ferti liser; land properly connected to the pipe system, ability for men to stand up while using chis application o n dedicated area, (e.g. in the these problems have not occurred. When unit withou t splashing, the UST chosen for Stage 2 of the research project) and off-site connected and operating properly, residents the project was the Gusravsberg unit reuse as a fertiliser to farmers who direccly from Swedish studies report that the odour (Figure 2), They were shipped from supply food to Ecovillage residents. problems in connection with UST do not Germany through the sup plier Berger To determine the initial feasib ility of using appear to be greater than with other toilers. Biotechnik (www.berger-biocech nik.de). urine as a fertil iser in the cropping areas, Urine collection and storage estimates o f areas required for uptake of Table 1. Estimated nutrient loads a nd urine fertilise r were calculated, and are At each of the 20 ho useholds involved in crop requ irements for w heat (values shown in Table 2. There is clearly sufficient the project at the Ecovillage the diverted for nutrien ts from STOWA , 200 2). land in the 110 ha development to urine will be collected from the UST into a sustainably reuse the nutrients from 20 or 30 0 to 500 L flexible polyethylene bladder Nutrient Urine kg/p/ yr 200 kg grain more houses. tank using a combination of stainless steel N 4.4 4.5 pipe and plastic hosing (see Figure 3). The In Sweden, it is common for tank wagons p 0.4 0.6 volume of urine solution generated will or tractors, equipped with a pump, to be K 1.0 1.0 equate to about 350 L per month, assuming used to spread urine solut ion using trailing 68 FEBRUARY 2008

Water

Journal of the Australian Water Association

technical features fe eed pap

decentralised s ~ hoses or tynes. Application should be subsurface with riming to coincide with active crop growth periods and should rake into account the potential of some crops to burn if ammonia is applied on the plants themselves. Chloride and sodium salts can be present at high concentrations. (e.g. EC of urine/water solution ~ 1 to 3 dS/m). Guidelines fo r rhe Use of Urine and Faeces in Crop Production Oonsson et al. 2004) will be used as a guide for establishi ng protocols for urine reuse during rhe project. A urine reuse management plan will be written and implemented, in consu ltation wirh Queensland Health and Gold Coast City Council.

Consultation and decommissioning Consultation with Queensland Health, the Environmental Protection Agency, Department of Local Government, Planning, Recreation and Sport, Gold Coast City Council, and Gold Coast Water has been undertaken. Implementation of the 20 household UST project may require M inisterial exemption under rhe relevant legislation (Plumbing and Drainage Act 2002) as a temporary research project. Ar che completion of rhe project, retrofit ti ng with a standard toiler unit, if desired by che householder, will be at rhe cost and responsibility of DNRW. Participants who choose to retain their UST wi ll do so at their own cost, and share respo nsibil ity with the Body Corporate who wi ll manage the pu mp-out of rhe USTs, and the urine storage and reuse scheme.

Conclusions Urine contains che most concentrated source of N and P in human wastewater and can be reused beneficially as a liquid fertil iser. Life cycle assessment of UST indicate rhar substantial energy savings ac rhe STP, and from reduction in fertiliser man ufacm re can be gained from separating urine ar rhe source. An Australian-first project where twenty urine separation toilets will be trialled at the Ecovillage at Currumbin is underway in southeast Queensland. The objectives of rhe firs t stage of the project are to quantify rhe recovery per

Table 2. Estimated nutrient loads and crop requirement data a ssuming 3 people per househo ld and 100% use of UST. Crop

kg N/ hh/ yrA

N uptake (kg/ ha) 8

Area (m2) required/ hh'

Area (ha) required for 20 households (hh)

Rice

8.6 8.6 8.6

150 · 200 135 · 225 200 - 400

s 300 s 200 s 215

s 0.60 s 0.40 s 0.45

Corn

Grasslands

A. Assuming 0.008 kg N per person/day B. Based on nutrient uptake rates reported in Reid ( 1990) C. Assuming 50% plant uptake efficiency

perso n of nutrients rhar are achieved by UST, explore the reuse alternative fo r urine, gauge rhe social acceptance of UST and assess disinfection efficacy using extended storage duration. The second stage of the UST project will focus on the potential crop production onsire from urine fertiliser. Swedish studies have shown rhar urine ferti lisers can achieve at lease 85% of rhar from yields fertil ised with manufacm red mineral fertiliser.

Scockholm: EcoSanRes Programme and the Stockholm Environment Institute .. Leinerc, J., Burki, B., Escher, B. (2007) Reducing micropollutanrs with source control: Substance flow analysis of 212 pharmaceuticals in feces and urine. Proceedings of lWA Advanced Sanitation conference, Aachen, March 2007 : 15.1 15.9. Maurer, M, Schwegler, P & Larsen, TA (2003) Nutrients in urine: energetic aspects of removal and recovery. Water Science and Technology, 48 (19), 37-46.

Cara Beal, Ted Gardner (email:

Maurer, M, Pronk, W & Larsen, TA (2006) Treatment processes fo r source-separated urine. Water Research, 40, 3 I 51-3 I 66.

red.gardner@nrw.qld.gov.au) and Warish Ahmed are with the Department of

Reid, R. (1990). The manual of Australian agriculture (5th ed.) . Butterworchs Pry Ltd.

Natural Resources and Water, Brisbane.

Schonn ing, C., Leeming, R., & Strenscrom , T. (2002). Faecal contaminarion of sourceseparated human urine based on the content of faecal sterols. Water Research, 36, I 9651972.

The Authors

Chris Walton is a Director of Land Matters P/L the developer of rhe Ecovillage ar Currumbin, and David Hamlyn·Harris is Director of Bligh Tanner Pry Ltd, Brisbane.

References Johansson, M. , Jonsson, H., Hoglund, C., Stinrzing, A., & Rodhe, L. (2002) Final Report for Source-Separated Human Urine: A

Future Source OfFertilizer For Agriculture In The Stockholm Region' Prepared for the Stockholm Water Company, Stockholm, 2002. Jonsson, H , Stinzing, A R., Vinneras, B. & Salomon, E. (2004) Guidelines for the Use of Urine and Faeces in Crop Production. EcoSanRes Publications Series, Report 20042, Stockholm, Sweden. Kvarnscrom, E., Emilsson, K., Richert Stintzing, A., Johansson, M., Jonsson, H., Petersens, E., Schonning, C., Christensen, J. , Hellstrom, D., Qvarnstrom, L., Ridderstolpe, P. , & Drangert, J. (2006). Urine separation: One step coward sustainable sanitation.

STOWA (2002) Separate urine collection and treatment. Options for sustainable wastewater systems and mineral recovery. Stichting Toegepast Onderwek Waterbeheer (STOWA), Utrecht, Holland, November 2002. Vinneras, B., Jonsson, H. (2002). The performance and potential of faecal separation and urine separat ion to recycle planr nutrients in household wastewater. Bioresource Technology, 84, 275-282. Watkinson, A., Murby, E. & Costanzo, S. (2007) Removal of antibiotics in conventional and advanced wastewater treatment: Implications for environmental discharge and wastewater recycling. Wat.Res., doi: 10.1016/j.wacres.2007.04.005. Wilsenach, J A, Loosdrecht, MCM (2006) Integration of processes to treat wastewater and source-separated urine. journal of Environmental Engineering, 132 (3), 331-341.

Journal of the Australian Water Association

Water

FEBRUARY 2008 69

tprhnical tPc:hnical features

centrifuges

fereed paper

COMPARING CENTRIFUGE CAPACITIES FOR SLUDGE DEWATER ING K Codee, A Hertle Abstract The assessment of decanter centrifuges from different manufacturers is not straightforward due to the absence of a simple model which accurately predicts centrifuge performance from first principles. T he process design engineer m ust therefore rely heavily on the experience and know-how of the man ufacrurer. In chis paper several key scaling parameters are introduced fo r the com para rive assessment o f centrifuge capacity wh ich may be used to compare machines o n a common basis. W h en com bined with thorough checking of reference installations these scaling parameters may be used to select the most suitable centrifuge for a particular application.

Introduction Over rhe past few decades there has been a general move cowards the greater use of decanter centrifuges for rhe dewacering of wastewater sludge worldwide. The same trend has also raken place in Australia, mainly in urban areas, driven by risi ng dewacered sludge disposal coses, limired space and the need to reduce odou r emissions at larger metropolitan plants.

Centrifuge Installation at Beenyup W astewater Treatment Plant in Perth. parameters to be d ireccly used to calculate the required decanter size and shape. In chis sicuarion, the process designer is highly dependen t on technical data and application know-how from the manufaccurers. This presents its own challenges, because rhe centrifuge manufaccurers have the best information on the capacity and performa nce of their machines, however p rocess design en gineers must make sense of o fte n co nflicting claims chat can result from a competitive ren der process. The reason for chis is char different centrifuge manufaccurers emphasise different features, and even different models from the same manufacturer may be different in key design parameters. All manu facturers quote maximum solids and hydrau lic loading fo r their mach ines, b ur chis informat ion should only be used when it is obtained from all manufacturers on rhe same basis - generally centrifuge capacities must be compared on a common basis to determine the most suitable machine for a particular application.

The Australian user can chose from a large number of decanter manufaccurers, wh ilst chis is generally positive, it does not necessarily make the choice easier. A diligent comparison of the technology and the process guarantees offered is required. However, compared to ocher equipment used on a wastewater treatment plant, decanter centrifuges are one of the more difficult items when it comes to technological assessmen t. The rwo main reasons are char rhe centrifugation process can not be d ireccly observed, as it occu rs inside a closed rotor, and secondly, there is no precise model for a decanter centrifuge which allows the sludge feed rate and other

Theoretical Considerations

Key scaling parameters to compare machines on a common basis.

The first rigorous analysis of the clarificatio n performance of decanter centrifuges was by Am bler (l 952). He introduced the "Sigma Concep t" as a means of scaling up (or down) between similar

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Water

Journal of the Australian Water Association

mach ines. This concept is based on the sed imentat ion of a homogeneous and spherical particle in laminar flow regime, described by Stokes' law. Determining the feed rare at which a particle of a certain cut off size can just be captured (actually 50% of those particles, as chis is the definition of the cue off point), leads to a result where ch is limiting feed rate can be expressed as fun ction of p roduce parameters (density, viscosity) and decanter parameters (radi uses, speed, etc). Ambler "summarised" chose parameters which are on ly functio ns of the centrifuge into one single factor "I".

The parameter is the area of a gravity seeding rank of equivalent sedimentation characteristics co the centrifuge. For deep pool decanter centrifuges, such as used for the dewacering of wastewater sludge, rhe is given in (1) below. This formula for formu la is slightly different to Ambler's original form ula, as the latter had been derived for decanters with shallow pools (r 1/r 2 ~ 0.75), which was the state of the art in those days (and is still used today for certain produces).

( I) W here L = th e bowl length (m)

tech n ica I features

r2 = the radius of the inner wall of the bowl (m) r 1 = the radius of the liquid surface (m)

w = radial velocity (rad ians/sec) g = acceleration due to gravity (m/sec2) Note: Equation (1) is a version of Ambler's formula which specifically describes deep pool decanters. .Ambler's original fo rmula describes shallow pool decanters. A number of simplifications for the L formula have been developed over the years (a nice summary of which can be fo und in Records and Sutherland, 200 I). W hen using L as a way of comparing L values from various sources, it is therefo re very important to make sure that all values have been calcu lated with rhe same formu la; otherwise very significant deviations can occur only due to the differences in rhe calculation method, rather than due to real di ffe rences in centrifuges. The Sigma Co ncept is based on a number of simplifying assumptions (Vesiland, 1979) chat do not truly reflect rhe actual conditions in rhe centrifuge and is therefore not particularly useful in accurately predicting rhe performance of new

centrifuge designs. Also, quire clearly, most products in real life do nor contain solids of perfect spherical shape or of one sharply defi ned diameter. Despite these limitations, rhe Sigma Concept may be useful in some applications to understand rhe relative clarification capacity of different machines of similar geometry and proportions developing similar centri fuge forces. Ir should be used with caution when the centrifu ge forces vary by more rhan a factor of two (Perry et al, 1973), or if rhe decanters' geo metry data is too different (e.g. one being a deep pond and the other being a shallow po nd machine). Ir is also usefu l to understand the potential impact of changes to rhe pool depth and rotational speed on the relative clarification perfo rmance of a particular machine. When used within tight limits, e.g. scale-up or down between very similar decanters of one manufacturer only, it is nor so important which L fo rmula is used, as long as the same form ula is used consistently.

Comparing Different Machines g-force The operating principle of decanter centrifuges is ro accelerate the naturally occurring separation of phases of different specific gravity by applying a gravitational field which is many times larger rhan natural gravity. One performance parameter fo r a centrifuge is rherefore the gravitational acceleration ir can produce expressed as multiples of rhe earth's gravitational acceleration. This parameter is usually referred to as g-force (though not a fo rce bur a dimensionless number). For rotating equipment, this factor is a function of angular speed and distance from the axis of ro tation. ?

g-force =

rar

(2)

For co mparative assess ments, rhe maximum g-force (gmaiJ may be calculated at the bowl wall (i.e. using the inner bowl radius r = r2) and ar maximum operating speed. An important aspect for th is analysis is the speed fo r which the g-force is calculated. Unfo rtunately the max imum operating

--- IMCD

Journal of the Australian Water Association

Water

FEBRUARY 2008 71

technical features

speed of a specific model is often not clearly shown in the technical information provided by the manufactu rer. Due to rhe importance of rhe speed, rhe process designer must therefore rake great care char information on the maximum operating speed has indeed been provided, rather rhan on the maximum speed. The latter is more of a mechanical design parameter, bur in many cases the decanter cannot be operated at chis speed, or may require further checks and/or modifications. If in doubt over the information on a specific machine, rhe actual operating speeds on comparable installations of the same machine should be checked. Ir is noted char mechanical stress, wear, power consumption, and noise increases with g-force. Naturally, for machines of othe1wise same d imensions, higher speed designs will be more expensive, but at rhe same rime, g-force is rhe key to compact space-saving designs, and for some products it is the only key to successful treatment. Cake dryness also increases with g-force. However, chis curve is believed to be nonlinear for wastewater sludges. Historically, the step from the slow machines (below and up to around 2,000 x g) to the modern high performance centrifuges (operating at around 3,000 x g) brought a significant increase in cake dryness and allowed significantly increased throughputs through smaller machines. A similar significant increase in cake dryness was however nor observed between 3,000 x g and 4,000 x g. From experience to date, approximately 3,000 x g seems to be rhe most advantageous operating point for wastewater sludge dewatering applications, offering a good balance between capital cost and spare part unit costs, wear and performance. There are however, many high quality centrifuges which can operate between 3000 x g and 4000 x g.

Equivalent Clarification Area For relatively d ilute wastewater sludge (typically < 1.5 - 4.0% TS), the hydraulic loading will most likely govern the capacity of the centrifuge. While the Sigma Concept could be used to compare the capacity of different machines, the operating pool depth is a variable that is determined as part of the commissioning and optimisation of the centrifuge and is therefore not known up-front. For rhe comparison of the capacity of decanter centrifuges with similar geometry, proportions and g-forces, rhe maximum value of I (r1 "' r2) may be used. Lmax

2 rc L

r/ oP g

72 FEBRUARY 2008

Water

(3)

Table 1. Comparison of four different centrifuges Parameter Inner bowl diameter

Solids discharge diameter

Bowl length

Length of cylindrical section

Length of conical section Maximum bowl speed

m rpm

gmox Lmox g-volume Maximum hydraulic throughput Maximum hydraulic load ing rotes

m2 m3 m3/h L/h per m2 Lmox L/h per m3 g-volume

This is equivalent to the inner bawl area (not including the conical section) multiplied by the g-force, and referred to as "equivalent clarification area". For example, the values of Lmax for four different centrifuges from four different manufacturers with inner bowl diameters in the range 500-550mm and treating a particular type of wastewater sludge are shown in Table l. From chis comparison of these h igh speed, high solids centrifuges, with inner bowl diameters in rhe range 500-550mm, the maximum hydraulic capacity of rhe centrifuge will be approximately 6L/h per m 2 of Lmax for chis particular type of wastewater sludge. Similar comparisons may be made for centrifuges with different bowl diameters. Also, chis method can also be used to scaleup and scale-down results from other sizes of rhe same manufacturer, provided char the product created, the process setup, and the decanter derails are comparable. Although the maximum hydraulic loading rate will be different for machines with significantly different bowl d iameters. This type of analysis can identify any manufacturers' claims chat may be ou tside the norm, which requires more detailed evidence of the claimed performance before accepting such claims. Centrifuges operated at lower loading rares (L/h per m 2 LmaJ are more likely to produce dryer cake, and better centrate ar lower polymer dose rates than otherwise similar centrifuges operated at higher loading rares. At the same time ir is noted char the selection of the most appropriate polymer and polymer dose rare often is more important fo r good performance than small differences in scaling parameters such as gmaxâ&#x20AC;˘ Lmax and g-volume.

Journal of the Australian Water Association

0.529 0.315 2.099 1.699 0.399 3250 3 123 8819 753 50 5.7

0.520 0.298 2.600 2.028 0.572 3200 2976 9860 862 60 6.1

0.544 0.300 2.359 l .592 0.767 3300 3311 9009 853 6.l

0.510 0.265 2.032 1.041 0.991 3800 4116 6865 639 40 5.8

g-pool surface area According ro the boundary layer theory the water flow pattern inside a counter-current solid bowl centrifuge is two-fold. A very chin layer on rhe surface of the annular pool is flowing towards rhe centrate outlet at very high velocity. Below this chi n layer, che bulk of the pool is stagnant in relation to che reference frame of rhe rotating bowl. After particles have seeded through the fast fl owing boundary layer (which includes significant lateral movement as per direction of che boundary layer flow) into the "stagnant" layer, they basically settle unimpeded and scraighc downwards (radially outwards). Once they have seeded on che bowl wall (or on top of existing sediment there) they can be conveyed by che scroll towards rhe solids discharge; during chis p rocess compressible products, such as wastewater sludge, are dewacered further. It is evident from this basic description of the liquid flow pattern inside a centrifuge, char che residence time of the liquid under the gravitational fiel d is a key parameter, because only che solids particles char have serried on the bowl wall or on top of an existing sediment layer can eventually be conveyed our of the machine as dewarered cake. Due to che pattern of flow, the hydraulic residence rime fo r the fast flowin g top layer of rhe pool is a critical parameter. Due to chis layer being very chin (of the order of millimetres), rhe pool surface is a more practical substitute for this parameter. As rhe centrifugal force determines the radial component of rhe vector of movement of the particles, pool surface area x g-force is often used as a scaling parameter. Ir fo llows from chis model char whatever passes through the fast moving rop layer

(approximated using the pool surface) has settled, the rhus calculated "g-pool surface area" and "equivalent clarification area" borh provide a measure for rhe clarification capacity of a decanter.

is based, is nor as inaccurate as ir may appear for wasrewarer sludges, because in rhis application, dewarering decan ters are usually operated wirh weir settings around neutral (ranging from slighrly positive to slightly negative pond).

For comparisons between different machines, the g-pool surface area may be calculated based on the solids discharge radius r, (" neutral pond depth") as rhe operating pool depth can only be determined fro m optimisation trials.

Commonly, g-volume may be calculated by multiplying the pool volume (not incl uding the conical section) by gmaxÂˇ 2

2 1< L (r2 - rs 2 ) t 2 oi g-volume = ----'--=--..::_'---=--g

Commonly, g-pool surface area may be calculated by multiplying rhe pool surface area (nor including the con ical section) by gmaxÂˇ g-poo l 2 1l L rs r2 w surface area = g

(4)

Ir should be noted however, chat neither of the surface based parameters is a truly objective measure for rhe capacity of decanters of various shapes and sizes and in particular not for various types of feed material. Both parameters can only be used to compare decanters following the same design approach fo r the same product. For example, the largest pool surface area is obtained when the pool radius approaches the inner bowl wall. For two decanters of same bowl diameter and cylindrical bowl length, this would make the one with shallower pool more powerful in regards to throughput. But a quick reality check reveals that wasrewater sludge decanters are so-called "deep pool" type decanters and are typically operated wirh more or less neutral weir setti ng, and even with negative po nd depth. According ro the g-pool surface area concept, this would be counter-productive; however, in practice rh is has been shown to maximise decanter capacity for wastewater sludges as well as many ocher produces (and reduce energy consumption ar rhe same time) . Due to these limitations, rhe authors do nor recommend rhe use of g-pool surface area fo r evaluating rhe relative capacity of decanter centrifuges fo r wastewater sludge dewarering. It does not provide any more meaningful information than the equivalent clarification mos, " "";fog~ ha,c gcoccally ,;m;l,c goomm ;, c,dos

'{; r

(5)

Centrifuges operated at lower loading rates (L/h per m 3 g-volume) are indicative of a longer residence time in the centrifuge for solids consolidation and are more likely to produce dryer cake, and better centrare at lower polymer dose rares than otherwise similar centrifuges operated at higher loading rares.

Relevance of Technical Parameters for Performance Guarantees Unfortunately, all of rhe parameters discussed above are unsatisfactory in many respects to their accuracy in determining a centrifuge's capacity. This shortcoming is however even more significant for ocher important design aspects, such as cake dryness, centrat e clarity or polymer consumption. T hese aspects cannot be calculated, and because decanter centrifuge design details may impact significantly on those parameters, it cannot even be assumed char decanters which are similar in geometry, speed and the technical parameters discussed above, will produce similar results in regards to these performance parameters.

---. = -8 ~ by-JaS ~

QUALITY ASSURED ENGINEERED PRODUCTS

g -volume

T he g-volume is a measure fo r hydraulic residence rime in the sedimentation area of the machine. Similar to pool surface area, the true volume of the liquid body in the centrifuge is not known upfro nt, so that g-volume (pool volume x g-force) based on pool radius equal to solids discharge rad ius ("neutral depth") is more practical as a parameter for upsizing of machi nes. In fact it is a similar parameter to pool surface area, but due to the shortcomings of the boundary layer theory in some aspects as discussed above, ir takes pool depth into account. In wastewater sludge dewatering applications, pool depth is typically large, sometimes to the extent where the surface diameter is smaller than the solids discharge diameter in order to maximise g-volume and hence capacity, and also in order to assist conveying rhe cake out of the centrifuge. W hile centrifuges may be tuned to operate in this mode, dewatered cake quality will be poor until a plug of solids has formed at the solids discharge end of the machine to prevent the loss of centrare with the dewatered sludge. It requires close operator attention to operate in this mode. For comparisons between different machines, the g-volume may be calculated based on the solids discharge radius, as rhe operating pool depth can only be determined from optimisation trials. The assumption of neutral pond on which rhe calculation of g-volume

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Journol of the Australian Water Association

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FEBRUARY 2008 73

The best way co determine che performance a particular centrifuge can achieve on a particular sludge is co carry out full-scale trials on-site. Optimally these tests should be carried ou c wi ch a cen crifuge of che same type, model and size as considered for the fi nal installation. Alcernarively, an on-sire rest with a centrifuge of the same type and model, bur different size, may be undertaken , though the size difference should nor be coo large. Of course, chis procedure would have co be carried out with each manufaccurer being considered for a specific project. Results from laboratory rests should be used with caution. Typically, laboratory tests are carried out with small bench centrifuges or other batch-wise working devices. Dynamic effects caking place in a full-scale centrifuge which are important for its performance do not rake place in such laboratory tests. Therefore, such cescs can be used co determine the suitability of decanter centrifuges for a certain product, and also co some extent che approximate determination of suitable polymer, polymer consumption and cake dryness. For a comparison between bids however, these tests are not suitable. As for other key equ ipment, the value of thoroughly checking installation references cannot be stressed enough fo r decanter centrifuges. Speaking to users about their operating experience, performance achieved (and how that compares co the performance that was originally guaranteed), as well as the operators' experience regarding service frie ndliness, maintenance costs, and support from the manufact urer or his representative - all th is is probably the most valuable information of all.

Determining Suitable Centrifuge Duties While centrifuges may be operated at the manufacturer's maximum quoted hydraulic throughput, for some situations the cake dryness may be sub-optimal and the polymer dose rate may have co be high co achieve good solids capture. For this reason it is recommended that in the absence of test or full-scale operating experience on the sludge co be processed, a hydraulic loading rate of approximately 50-70% of che maximum throughput be used for sizing centri fuges as this will likely achieve a good balance between capital cost of the centrifuge cake dryness and polymer consumption. It is also desirable that che normal solids loading race not exceed 5070% of the manufacturer's maximum loading race for good cake dryness and low polymer consumption. The maximum raced solids load usually relates co che capacity of the sl udge conveyor rather than the capacity

FEBRUARY 2008

Water

of the machine co perform optimally in terms of cake dryness and polymer consump tion. In che design of centrifuge installations, it is important that the right balance be set between being overly optimistic in the capacity of the machines and not being coo cautious. The degree of conservatism used in the selection of centrifuge selection is of course also dependent on che availability of on-site testing information, previous experience with the particular sludge co be dewacered, the budget available, as well as the relative importance of capital cost versus operating cost for a specific project. In any case, it is uttermost important co consider downtimes, planned and unplanned , in the design of a centrifuge plant, e.g. by installin g stand-by capacity, or by holding a spare rotating assembly in stock, or by over-sizing the decanters such, chat in case of one being out of service, the ocher units can cover.

Example 1 Three duty machines sized co operate 140 hours per week (20h per day) at the maximum weekly so lids production rate and conservatively loaded at about 50% of the maximum load ing race, also have che capacity co process che maximum weekly solids production with two duty machines operati ng 154 hours per week (22 hours per day) at 70% of che maxim um loading rate. During periods when the centrifuges are heavily loaded, the polymer consumption may be higher than normal and cake dryness may also deteriorate, but not to a significant degree. In chis case, it will likely be beneficial to operate all centrifuges when available co achieve che lowest polymer consumption, albeit at the expense of slightly higher energy consumption.

Example 2 Two machines sized co operate on a duty/standby basis 40 hours per week (8 hours per day) 5 days per week at che maximum weekly solids production race and loaded at 70% of the maximum loading rate, also have the capacity co process the maximum weekly solids production with two duty machines in 7 hours per day/4 days per week at 50% of the maximum loading race. Alternatively, one duty machine would have the capacity co process the maximum weekly solids production in 8 hours per day/7 days per week, at 50% of the maximum loading rate. This will provide a very flexible and robust dewacering facility where the preferred operating mode may be established by

Journal of the Australian Water Association

optimising the trade-off between operating times and polymer consumption.

Summary Several parameters for the assessment of a decanter centrifuge's capacity or fo r comparison of several decanter centrifuges have been introduced. A closer look at those parameters reveals that the best picture is obtained if not just one, but several parameters are analysed in the course of a bid evaluation, as several aspects of centrifuge physics are important for its performance. No single parameter covers all these aspects. When comparing the relative capacity of different centrifuges for wastewater sludge dewacering, the authors recommend chat che greatest weight be given co g-volu me with equivalent clarification area, g-force and operating speed used as seco ndary indicators of centrifu ge capacity and performance. In spite of these performance parameters, performance guarantees can only be assessed on che basis of truly comparable on-site tests. As these are often not available, the im portance of a thorough and diligent check of installed references is stressed. In the absence of on-site testing, or previous experience, a conservative approach is recommended, wherever the budget allows it. In any case, the management of planned and unplanned downtimes is a key aspect in the design of a dewaceri ng fac ility and should be carefully considered as pare of the design.

The Authors Keith Cadee is General Manager Water Tech nologies Division, Water Corporation, Leederville, Western Australia 6007. Email: keich.cadee@watercorporation.com.au; Arnim Hertle is Senior Process Engineer and Sales Manager of Hiller GmbH , Schwalbenholzscr. 2, D-84137 Vilsbiburg, Germany. Email: hercle@hillerzentri. de. He is also working as an independent process engineer, providing consulting services for aeration systems and sludge treatment systems. Email: arnim.hercle@gmx.net References Ambler, C. M. ( 1952) The Evaluation of Centrifuge Performance. Chem. Eng. Prog.

48:3 Vesiland, P. A. ( 1979) Treatment and disposal of Wastewater Sludges. Revised Edition, Ann Arbor Science Publishers, Inc. Perry, R.H. and Chilton, C.H. (1973) Chemical Engineers' Handbook, Fifth Edition; New York, New York. McGraw-Hill Records, A. and Sutherland, K (2001) Decanter Centrifuge Handbook, First Edition, Elsevier Advanced Technology, Oxford (UK)

refereed paper

CUSTOMER SEGMENTATION IN THE RESIDENTIAL SECTOR K La, K Vinot Abstract There are many driving factors in relation co water conservation that influence a custo mer ro limit their consumption of water. This paper discusses how these driving factors have been used ro produce a segmentation solution. T here is also discussion on the relevance of segmentation ro a public water uciliry and how it has been applied co water conservation and produces and services marketing.

Introduction Segmentation efforts have gained momencum in che private sector as more and more businesses seek co gain an edge over their co mpetitors ch rough providing tailored solutions chat meet their customers' expectations better than their competitors, or through their ability ro acq uire rhe most profitable customers in a particular marker. Segmentation identifies customers and customer groups with similar groups of characteristics, providing businesses with the ab ili ty co match rhe best sales prospects ro specific prod uces and services in order co maxim ise rhe return on investment.

As a pu blic water utility with monopoly rights ro provide water and sewerage services co a particular geographica l region, Sou ch Ease Water does not have co compete for its custo mers. However, its primary produce, potable water, is in shore supply. The relevance of customer segmentation for So uth East Water is therefore nor rhe acquisition of profitable customers bur the necess ity co understand its custo mers' water needs co ensure desired behavioural change. Th is paper discusses how South Ease Water recently segmented its residential customer base using a data-driven analytical approach. The intention is co develop a segmentation solution chat can be applied in practice over and above understanding customers' water needs. Application areas include targeted products and services campaigns and tailored water conservation programs.

Previous Studies Segmentation has previously been considered as a viable method for demand management. The Melbourne water

authorities collectively commissioned Newton Wayman and Chong (2001) co undertake a market research project that explores customer values. T he study produced a segmentation profile based on a survey sample of 1411 which encompassed attitudin al themes such as: • the level of importance customers place on water usage in their lives, • percep tion of the need co save water, • beliefs around a customer's right to as much water as they need, • perception of cost, and • atti rudes ro indoor and outdoor water usage. These attitudi nal themes are based on the scudy undertaken by Nanca rrow, B E and Syme, G J (1989). Sydney Water has used segmentation together with an End-Use Demand Model (Sydney Water (2005)) co prioritise target areas for demand management options. Other studies including Eardley et al. (2005) and [PART (2004) profiled households based on socio-economic va riables chat drive high water usage.

Background T he Victorian Government's Central Region Sustainable Water Strategy (Department of Sustainability and Environment, 2006) aims at reducing coral per capita water use across Melbourne by 30 per cent from 1990's average by the year 2015. Mass-marketing campaigns run by the retailers and Government, particularly the co-funded Our Water, Our Fu cure programs (Depa rtment of Sustainability and Environment, 2004), had resulted in per capita water co nsumption falling ro 22% below 1990 levels by mid-2006. This was achieved without water restrictions fo r most of the period.

Applications for targeted products, campaigns and tailored water conservation programs.

Although water restrictions have been used recenrly in Melbourne in response ro the parti cularly dry conditions in 2 006/07, work is conti nuing co find ways in which customer's water consumption can be reduced on a voluntary basis. H owever, it is questionable how much fur the r water consumption can be reduced through massmarketing programs. South East Water's Towards 2015 Vision is for the company to expand its core functions ro offer a range of leading products and services to meet cu stomers' needs in a supply-constrained world. T he organisation has ro meet chis objective and at rhe same rime, meet the above water conservation targets sec by the Government.

Water Conservation Segments Sou ch East Water in the past has divided its customer base in one way or another, and have referred ro chis practice as 'segmentation'. The most common approach has been ro segregate data acco rding ro readily-available characteristics such as postcode or geographical region or into broad categories such as residen rial/non-res idential, trade waste customers, houses and uni ts or Aacs, and concess ions for a number of pen sion categories. T hese themes have often been referred co in rhe organisation as 'segments' bur they are based on readily available data or categories of convenience rather rhan their ability ro provide insights into how co better deliver on rhe business's s trategic goal of offering a more extensive range of produces and services ro meet cu stomers' water needs. South Ease Water needs co be ab le ro segregate its customers into groups that reflect chei r water use preferences and the driving factors char influence chem co change their behaviour. T hese range from rhe most fundamental survival need ro ear, drink and go ro rhe to iler, co their social and culcural needs fo r showering, swimming, washing, cooking and doing the gardening. How much and how often a customer carries our these activi ties, and how South Ease Water can influence their level of consumption, will depend on the type of customer char they are, w h at their lifestyles are like, and what their atticudes

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FEBRUARY 2008 75

Table 1. Data used in Segmentatio n Model. Customer Value & Loyalty

Household Demographics

Customer Lifestage and Lifestyles

Geodemographic Attributes

Psychographic Attributes

Level of consumption

Pension status

Leisure interests e.g. gardening

MOSAIC classifications

Will consider using renewable/green energy

Rebate applications: rainwater tanks, greywater

Household composition and size

Professional occupation

Postcodes

Showerhead exchanges

Age grouping

Conduct business at home

Local government areas

Income grouping

Level of education

are cowards water conservation. If there are so many characteristics that can define one water user from another, why should any organisation in che water industry settle on making business decisions based on results derived fro m just one or two conven ien tly available defining characteristics? T he approach adopted by South Ease Water is an analytical, data-driven propensity modelling approach using commercially available data bases, proprietary customer data and data mini ng techniques char reveal hidden patterns and relationships in data and infer rules about the future. The data mining methodology used, simultaneously classifies customers based on: • Customer value, primarily by their level of consumption and secondly by their loyalty and advocacy towards water conservation; • Household demographics; • C ustomer life stage and lifestyles; • Geo-demographic attributes: the demographics o f the area in which customers live; and • Psychographic attributes: customers' values, motivations and attitudes towards water conservation, which ultimately determine behaviour. All of these variables are used to produce a multivariate segmentation model char not only categorises significant driving factors b ur also produces a single response objective for an individual customer. The model is termed multivariate as it simultaneously accounts for all factors.

Customer Data Actual billed consumption d ata for residential houses was used. Dara for unics/flacs was filte red our as usage patterns within these property types are very different to chose of houses. Quarter 4 winter consumption data of the 200 4/05 and 2005/06 financial years were used. These were chosen because the same Permanent Water Saving Rules were in place during both periods, and the lace autumn/winter period minimised the likelihood of outdoor use, allowing the 76 FEBRUARY 2008

Water

segmentation model to determine any natural behavioural change without the imposition of external influences such as water restrictions and the recent droughtdriven media interest. South East Water purchased data from various external sources to enhance the breadth of custo mer information already available internally. These included demographic variables such as income, household composition, customer lifestyles and geographical classifi cation. Table 1 summarises the data variables used in building the segmen tation model. Given char consu mption data from as fa r back as two years ago was used, only chose customers who have lived at their current address for at least cwo years were selected , and it was assumed chat any changes were insignificant. Of South Ease Water's 580,000 residential customers, 160,000 data points rep resenti ng 28% of the total base were available for seven of the 15 variables after accounting for the above assumption. T he dataset of 160,000 records was used for the model building. The seven variables are level of consumption, pension status, household composition and size, age grouping, MOSAIC, postcodes, and local government areas. Even though data is available for all of these variables, some will be d iscard ed due to their high correlation with each other. Data on the ocher eight variables was available bur for a much smaller percentage (<10%) of the complete customer base. Such a small percentage did not contribute a significant amount of information in the analysis.

Analytics and Data Mining The objective fo r South East Water is to identify chose customers who have a propensity to increase or decrease their water usage defined by a log odds index which is based on the actual change in their billed water consumption between the Q4 winter period of 2004/05 and of 2005/0 6. Customer characteristics were firs t categorised into homogeneous clusters and classification b ranches, or 'customer

Journal of the Australian Water Association

segments' using the data listed in Table 1 and data mining techniques. As there are quite a number of customer characteristics to consider, segments were required to be further refined and customers further d iffe rentiated . For chis, segments were broken down iteratively into sub-groups called microsegments using the same techniques. The aggregated probability of increasing or decreasing consumption in the second winter period (Q4 05/06) compared to the first (Q4 04/05) was calculated. The propensity fo r a customer in a microsegment to increase or decrease usage was then determ ined by a relative index, defined by a log odds index, using the aggregated probability for chat microsegmenc. A positive index for a microsegmenc represents a propensity to increase and conversely, a negative index represents a propensity to decrease. The mai n data mining techniques chat were used to construct the microsegmencs are classification 'tree' and clustering techniques. These algorith ms were used to estimate a customer's propensity to change their water usage in the future given a number of significant variables which are current characteristics, such as household co mposition, pension status, recent consu mption levels, and affluence levels. C lustering and classification tree algorithms are compu ter-based iterative algorithms whose purpose is to detect significant clusters in the given variables and to assign customers into their respective clusters. For a more comprehensive technical description of the techniques, see Witten and Frank (2000) and Breiman et el (1984). In essence, tree techniques are appropriate to use when there is a single objective, in chis case, a response in terms of propensity to either increase or decrease usage. The single objective can be classified into mulciple groups and the purpose is co fi nd mutually exclusive branches char maximise discrimination and understanding of the objective. In practice, every individual customer muse be allocated co one and only one segment, there should be no overlaps and every customer must be allocated. This

of course is because a customer can not be described wirh more rhan one conflicti ng set of characteristics, or ic would nor be possible co separate rhe target markers. Tree techniques allow identification of segments of customers who have a propensity co increase or decrease usage. T hey do nor, however, in isolation allow rhe calculation of the degree of likelihood co increase or decrease usage. T o address chis challenge, the use of rhe tree technique is used in combination with rhe log odds ratio, allowing the degree of likelihood fo r a whole segment co increase or decrease co be determined. Tree techniques are only capable of assessing rhe propensities of each individual segment. Regression-based techniques are a further, more soph isticated approach which allows assessment of rhe propensities of each individual customer. Regression-based techniques were nor used in chis data segmentation project bur represent a potential fu ture application of the data segmentation ar South Ease Water. Results

T he segmentation model resu lted in rhe identification of fou r major segments char have been classified firs tly by their pension status, which is rhe first level used in explaining rhe distinction between each n:ee branch. These four segments were fu rther subdivided into a coral of 17 microsegments based on a cusromer's household composition and winter consump tion level during che 2005/06 year. From here, it is possible co identify the distinct microsegmenrs chat have a propensity co increase and decrease. T he fo ur segments and associated microsegmenrs are shown in Figure 1. T he most significant factors driving rhe propensity of a customer co increase or decrease their water co nsumption, under si milar seasonal conditions and Permanent Water Saving Rules, can be described as fo llows:

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• Pension status - representing aged pensioners, sole parents and customers on disability pensions

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- low - less than 352 1/hh/day - medi um - between 352 and 560 1/hh/day - high -between 560 and 813 1/hh/day - very high - greater than 813 1/hh/ day • Household composition - representing households contai ni ng homeshares, singles, couples or fa milies The iterative algorithm underlying rhe tree technique determined rhe number of customers co classify into each group fo r a given significance level and judgement was used co decide che number and type of segments char made business sense. Sample sizes within each microsegment cannot be coo small, nor can there be coo many segments, as their applications can become irrelevant. An intuitive driving factor would be the size of rhe household, or number of people living at the property. H ousehold size was analysed in the modelling process bur did not end up fo rming a direct component of the model as ic was cross-correlated with consumption levels and household composition. One interesting behavioural insight char can be seen in Figure 1 is char chose customers who are already the lower users of water have a propensity co decrease and chose who are already the higher users have a propensity co increase. This is an important insight into customer behaviour. Lower users of water are more likely co decrease consumption bur when they do decrease, their anticipated water savings will be relatively smaller given their already low consumption levels. Higher users of water are more likely co

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Journal of the Australian Water Association

water

FEBRUARY 2008 77

•

increase co nsum ptio n but when they are able to ach ieve water savings however, it is anticipated chat relatively larger gains are possible. T o understand t he 'portrait' of each m icrosegment, they were furthe r profiled using MOSAIC, a comm ercially-avai lable geodem ographic data base chat classifies customers according to where they live as well as the lifesryles they lead and their level of affluence.

•

Propensity to decrea se

Propensity to increase

SEGMENT 2

SEGMENT4

IIIGMINT 1

SEGMENT3

Pensk>n Status • Yes

Penalon Status • No

Penllon lllllle •YM

Penak>n Status • No

3 mlcroeegmenta

S mlcroHgmenta

lml--si-

• m lcrosegmenta

High IO Vtl'f ._h W1111r

Medium to Very High Water User Singles, Couptes, FamilM;a, or Hon,eshlres

Low to Medium Water User Singles, Couples oc F1milfe1

Low to High WalefUIOf

u..r

81nglot, CauplN, or F1mlll

Singles, Couples, Famor Hometh1ret

Figure 1. Da ta-derived seg ments a nd mi crosegments of 160,00 0 custo mers.

Strategic Outlook

Figu re 2 is a bubble chart chat shows the level of consumptio n of customers in all of the 17 microsegm ents and their propensity to in crease or decrease their water usage. T he sizes of the bubbles offer an indication of the number of customers in each m icrosegmen t. The b ubbles in the red zone on the right hand side of the chart represent chose customers who have a propensiry co increase whilst the bubbles in che green zone on th e left hand side of the chart represent chose who have a propensity to decrease. Strategically, the business m ust strive co move customers out of the red zone on the right and into the green on the left. W hile it may be tempti ng to ignore the customers in the green zone as they have already reduced their consump tion and appear likely to continue to do so, it is very important chat these custo mers contin ue to sustain their low water usage patterns. If they should become frustrated at on-going demands on them to reduce water use when they feel they have already worked hard, without any reward, they may become d isengaged and decide to reduce their efforts. To encourage customers in these segments to remain loyal to water conservation, the business would want to employ som e type of reward and recogn ition strategy Indeed, a recent direct marketing p roject conducted by South East Water identified that the vast majority of the 100 customers who volunteered to participate in th e water audit and receive individual advice, were keen co show South East Water what they were doing and co receive fee dback chat they were indeed low water users. (See Field force (2007) and case study p resented below) .

m icrosegments are further analysed and tailored p rograms are developed to reduce customer water consu mption o r provide loyalty p rograms fo r custom ers seeki ng recogni tion o f their o n-going good water pe rfo rmance. T he data also needs co be revised and updated periodically as custo mers are continuously going through different lifestages and their water usage patterns change to reflect changes in their lifesryles. Analytics, data min ing, and database management expertise are required no t only to develop the segments bm also co develop programs and cam paigns that b efit the business strategy. Marketi ng and co m munication expertise is req uired to deploy targeted messages . Using the sorts of d ata segmentation techn iques ad op ted in com petitive private industry, South East Water believes it can ach ieve greater overall water conservation im pact, more cost-effective ach ievement of water conservation goals and greater uptake of new pro ducts and services co better manage water use. H owever, there is also a business cost co not implementi ng effective data segmentation, namely wastage. Water

customers are currently evolving at a m uch quicker pace than the water industry can keep up w ith and u nless the approaches are tailored cowards their m ost effective outco mes, resources can be wasted on chasing 'low-value' custo mers, and w ith missed op portun ities from gaining 'h ighvalue' loyal customers. In terms of the benefits of segmen tation, the return on investment for communicating to a highly targeted, segmented market compared co the m ass market is the p reventio n o f many custo mers b ecoming annoyed w ith on-going com mu nications about saving water when they have already undertaken significant savings and the prevention of not attracting the attention of ocher customers who have no t made efforts co achieve savings with irrelevant, general ised messages chat do not h it the m ark in triggering reductions in co nsumptio n. Hence, segmentation provides a streamlined , p roactive app roach that opt imally cakes advantage of opportun ities and eliminates high-cost, low-value pursuits. It also aids in appropriately allocating enough resou rces to the right

Microsegmonts

The Costs and Benefits of Segmentation The main cost to South East Water of undertaking chis segm entation project was the cost of p urchasing and analysing the externally acquired data. Add itional costs will be incurred as the

FEBRUARY 2008

Water

.,oo

.75

.50

-25

100

Propensity to Increase/Decrease Water Usage

Figure 2. M icroseg ments according to propensity to decrease/increase consumptio n.

Journal of the Australian Water Association

(

fu nctional business areas by minimis ing wastage.

Applications South East Water has begun to use these segments. Targeted campaigns have been developed to deliver rhe showerhead exchange programs required by the Strategy, and will soon be applied ro a large scale household assessment program. The business will also use the segments in developing its Products and Services Portfolio. The following case study describes rhe application to a small pilot household assessment program that was recently implemented.

Cose Study In early 2007, South East Water commissioned FieldForce Services Pry Ltd ro implement a pilot househo ld assess ment program, named as "Warerl00 ", rhar targeted 100 customers within the service region. The program was aimed at achieving a positive change to customers' behaviour rhar would lead to a measurable reduction in water usage through individ ual water advice, internal and external household assessments and solutions. Customers of above-average affluence residi ng in the local cou nci ls of the City of Kingston and City of Glen Eira in suburban Melbourne were targeted to receive a direct mail recruitment lerrer and brochure with instructions to call in for the offer. When Water I 00 co mmenced, water conservation segments had nor been developed yet and so geodemographic criteria were used to select rhe target marker. The offer was limited to the firs t 100 callers who could receive a co mplimen tary household and garden assessment, water saving advice and a showerhead retrofit. The response rare of more than 10% (383 callers) in terms of number of telephone calls expressi ng interest in participation was much higher rhan expected. The response to the program by the 100 recruited participants was very positive wich indications char they wanted to do something about rhe current water shortage and wanted more education, reassurance and recognition rhar they were doing the right thing co help the community. After program completion, che Warerl 00 participants were mapped onto the water co nservation segments using the classification rules sec by the segmentation model. The response races found for segments 2 and 4 are about 8% respectively and about 4% for segments 1 and 3 respectively. The higher percentage

amongst those in segments 2 and 4 who have a propensi cy to decrease rei rerare che point rhac these are the customer groups who are loyal towards water conservation and are good sales prospects for a service such as these household assessments. Ir is still too early though co assess whether there has been any measurable water savi ngs achieved as a resul t of this household assessment intervention. If programs such as the presented case study prove co be effective, they would trigger a change in behaviour char leads to customers ' migrating' From a ' low value' segment to a 'high value' segment. Segment profiles over rime would change as more and more direct marketi ng activities make an impact on customers' behavioural patterns. Ic is therefore paramount to track usage patterns and to uncover any segment migration over rime in order to keep our pulse on rhe customer.

Future Challenges T he work char has been done so fa r is only the start of a journey that is breaking into new terrain for the business. As che orga nisation evolves into a customer-centric business, customer segmentation provides rhe foundation for better understanding the needs of our customers - nor just the basic fundamental physiological needs bur also their social and cu ltural needs. This can be effectively achieved primarily th rough accessing and collecting rich data sources and using data-driven, quantitative analytics and supported by qualitative analyses. Challenges for the immediate furure are for rhe busi ness to apply segmentation to targeted marketing campaigns and to measure how effective campa ign strategies have had on customer behaviour and on che level of uptake of the product or service offering. A furthe r challenge for che business is to develop data collectio n strategies utilising our existing channels and to be set-up in a way rhar will allow more analytics and data mining ro be done and messages and offerings to be disseminated across rhe board.

Concluding Remarks Prior co che commencement of rhe work described in this paper, there were questions raised as to rhe relevance of customer segmentation techniques to a public uriliry such as South East Water. Through a process of change management and influencing and engaging stakeholders, segmentation is now been recognised as an applicable means, especially when it provides che supporr mechanism for one of

che strategic directions of che o rganisation's Towards 2015 Vision.

Acknowledgments We thank the Branch Managers in Corporate Strategy, Customer Service, and Marketi ng & Communications for their comments, Feedback, support and encouragement and open-mindedness to change.

The Authors Kacie La, ac rhe rime of writing, was Manager, Strategic Analytics, working in rhe Corporate Strategy Group at South East Water. Kate Vinot is Acting Chief Executive Officer, South Ease Water Limited. Email: Kace.vinoc@sewl.com .au

References Breiman, L., Friedman, J. H. , Olshen, R. A. , & Stone, C. J. ( 1984). Classification and regression trees. Moncerey, CAz: Wadsworth & Brooks/Cole Advanced Books & Sofrware. Deparcmenc of Suscainabilicy and Environment (2004). Securing Our Water Future Together Our Water, Our Future. Victorian Government White Paper. Department of Suscainabilicy and Environment (2006). Central Region Sustainable Water Strategy. Viccorian Governmen r. Eardley,T., Parolin, B. and Norris, K. (2005) .

The Social and Spatial Correlates of Water Use in the Sydney Region, Final Reporc of a research projecc for che Wacer Futures Research Alliance, Universicy ofWescern Sydney. Field Force (2007). Household Engagement Pilot Program. FieldForce. !PART (2004) Residential Water Use in Sydney, the Blue Mountains and illawarra, Research Paper No. 26, Independent Pricing a nd Regulatory Tribunal of NSW, Sydney. Nancarrow, B.E. and SYM E, G .J. ( 1989).

improving Communication with the P11blic 011 Water lnd11st1y Policy Issues. Urban Warer Research Associacion of Ausrral ia:Melbou rne. Research Reporc No.6. Newcon Wayman Chong & Associaces (200 I).

Customer Values St11dy - a Research Report on Qualitative Stage, Syscem Securi ty Scandards Srndy Group, 72, Melbourne. Sydney Warer (2005). Water Conservation and Recycling implementation Report 2004-2005, Augusc 2005. Troy, T., Holloway, D. , & Randolph, B. (2005). Water Use and the Built Environment:

Patterns of Water Consumption in Sydney, Research Paper No. I , Cicy Fucures Research Cenrre, Universicy of New South Wales. Webber, R., Dove, M., Shaw, C., Sarson, A. (2002). Segmenting/or Profh. The lnscicuce of Direct Marketing and Experian Micromarkecing. Winen, I., H., & Frank, E. (2000) . Data

Mining: Practical Machine l earning Tools and Techniques. New York: Morgan Kaufmann.

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.fereed paper

DISINFECTION BY-PRODUCTS: AN AUSTRALIAN VIEW M Drikas, P Singer, C Chow, M Holmes Abstract T h is paper summarises research into the formation of disinfection by-products (DBPs) in a selection of typ ical Australian waters. It then discusses the mon itoring limits recommended by the Australian Drinking Water Guidelines and notes chat b rominated HMs, which are more toxic th an the chlorinated species, are not specifi cally covered in the Australian

Drinking Water Guidelines. I n Australia, a gu ideline level has b een established for total trihalomethanes (THMs) encompassing both ch lorinated and brominaced trihalomechanes species whereas for the o cher major class o f halogenated DBPS, h aloacecic acids (HM) species only rhe th ree chlorinated species have guideline values. H owever, there is mounting eviden ce chat bromin aced DBPs are more toxic than their chlori nated counterparts. I n the South Australian water supplies stud ied, brominated HMs were fou nd to dominate overall HM occurrence. Including guidelines fo r brominaced HMs within the Australian D rinking W ater Guideli nes would encou rage im proved monitoring and enhance the understand ing of the full extent of DBP formation and public exposure to this class of DBPs.

Introduction Disinfection is a key component in providing a safe drinking water supply to consumers with chlorine the most widely used d isinfectant. The cond itions in Australia invo lve the presence of h igh concentratio ns of natural organ ic material (NOM) lo ng pipelines, correspondingly high resid ence times, and high water temperatu re in many supplies. These result in a high disinfectant demand and, therefore, the p roductio n of appreciable levels of DBPs. T H Ms were the fi rst reported halogenated by-p roducts to be identified, and the fi rst investigated for potential adverse health effects As a resu lt, rhey have been the main focus of guideli nes and regulations developed by national and international health organ isations. W ith time and co ntinuing research effort, add itional by-p roducts have been identified and indeed continue to be

FEBRUARY 2008

Water

identified. Th is has prompted the inclusion of other halogenated DBPs, such as haloacecic acids (HMs), into th e regulatory arena, and th ere is an increasing awareness of rhe p resence and potential p ublic health impact of many o ther unidentified D BPs. The extent of H M for mation in Australian water supplies is certainly not as well understood as in US water supplies. Whilst the epidemiological evidence linking any specific DBP or class o f D BPs with a particular health impact co nt inues to be complicated by the complexity of DBP mixtures in different water sup p lies and proper assessment of DBP exposure, there is an increasi ng body of evidence for a link between chlorinated water and an increased bladder cancer risk. Studies to minimise DBP levels in tap water have used THMs as a surrogate for overall DBP form ation, bu r recent research has demonstrated chat approaches which minimise T H M formation may not necessarily impact o ther DBPs to rh e same extent. T he removal of N OM, the recognised precursor for the formation of many of these D BPs, co ntin ues to be an essential treatment strategy in reducing overall DBP fo rmation, b ut an increased awareness of th e impact of b romide on DBP formation and speciation has added to the complexity of ch is issue. A recent visit by Professor Philip Singer fro m the D rinking Water Research Center, University of North Carolina at C hapel H ill, USA, supported in part by the Cooperative Research Centre for Water Q uality and Treatment (CRCWQT), has reinforced rhe importance of understanding the extent of DBP fo rmation in our drinking water. This paper discusses the issues related to DBP formation and associated regulatory policies in Australia, with specific d iscussion relating to the drinking water gu idelines and standards implemented for HMs. Methodologies to describe the extent of b romine incorporation in to DBPs are presented and are used ro assist in understand ing the extent of formation of

Brominated haloacetic acids are potentially more toxic than THMs.

Journal of the Australian Water Association

b rominated H M s and overall HM occu rrence in Australia.

General Conditions in Australia Australian d rinking water can be sourced fro m either surface or ground water supplies. Surface supplies can in turn be sourced fro m a confi ned catchment and/or a river. T he dissolved organic carbon (DOC) concentratio ns of source waters are qui re d iverse - ranging from very low(< 2 mg/L) to very h igh (> 15 mg/L) T reatment of supplies having a h igh sou rce water DOC concentration typically use several clarification processes, including coagulation/ flocculation/ sedimen ration/filer ation prior to disinfection, wh ile treatment of water with a low D OC concentration may consist simply o f disinfection. However all drin king water supplies must include a disi nfection step. Commo n practice is to ensure char an adequate co ncen tration of disinfe ctant (chlorine o r chloramines) is maintained throughout the d ist rib ut io n system to prevent bacterial recontamination and re-growth. Determining a d isinfectant residual sec-po int for water entering the d istribution system, particularly for systems with a h igh residence time, presents a significant challenge for network managers, as a balance muse be achieved between meeting bacteriological, DBP, and aesthetic water quali ty go als. Conditions in Australia make control of disinfectant residual particularly d ifficult in distribution systems. In add ition to many source waters containing a h igh DOC concentration, extreme water temperatures (> 40Â°C) may also b e experienced an d both lead to increased d isinfectant dose requiremen ts at treatment plants . T h e combinatio n of h igh source water DOC, high tem perature and h igh d isin fectant d ose contribute to increase the potential to for m DBPs. A snapshot o f total T H M fo rmation potential (su m of all fou r THM species), based on laboratory chlorination stud ies for several water supplies collected fro m different pares of Australia, is shown in Figure 1. Based on this survey, T H M fo rmation from the chlorination of several of the raw waters was higher than the recommended

guideline of 250 µg/L sec by the Australian Drinking Water Guidelines (ADWG) (N HMRC, 2004), but fo llowi ng effective treatment, THMs were below chis guideline. From che same data sec, a general trend of higher THM formation potential levels wich higher DOC concentration was observed. In addition, specific coral THM (THM co ncentration normalised per mg/L DOC) can be used co show che link between THM formation potential and organic carbon characteristics. In Figure 2, the specific coral THM formation potential of chis sec of water samples was in che ra nge 17 co 43 µg/mg C. The face char these samples have different specific TH M formation potentials indicates char che character of the DOC differs among samples, wich some of the DOC having a higher potential for formation of THMs. In general , waters with higher DOC levels have higher specific THM formation potentials. Also, by comparing che raw and created water samples of che same supply in chis data sec, it is apparent that the treated waters have a lower specific TH M formation potential, indicating the preferential removal ofTHM precursors by conventional treatment processes (coagulation/ floccu lario n/ sedimen ration/ filtration). Similar findings have been reported by others (Liang and Singer, 2003).

:::r C)

300

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'iii 200 0

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Figure 1. Total THM formation potential from laboratory chlorination of selected water sources around Austra lia (for water sources incorporating treatment, THM formation from both raw and treated waters are shown). Dashed line represents Australian Drinking Water Guideline (Chlorination conditions, pH 7.2, 40°( , 30 min and 20 mg/L Cl 2].

45 40

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Conventional Treatment Process for DOC Removal and THM Reduction

Although che results in Figure 3a indicate chat maximum NOM removal occurred at pH 5, the residual aluminium concentrations at char pH exceeded che N HMRC guideline value of 0.2 mg/L (_Figure 36). T he best compromise co

400

::::,

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DOC removal and T HM reduction is a key research focus of the Water T reatment Tech nology program of the CRCWQT, with a number of projects established co identify che best approach co achieve chis outcome. Conventional treatment incorporating coagulacion/flocculacion/ sedimentation/filcracion, is widely used in Australia. The co ntrol of pH during coagulation is one of the most important factors impacting NOM removal (Babcock and Singer 1979; Young and Singer, 1979; White eta!, 1997; Chow eta!., 1999; Drikas et al. , 2003) . In Figure 3a, the relationship between DOC removal and alum dose at different pH values fo r a high DOC source water (S upply H ) is presented. From the dose-response curves, it was found chat maximum DOC removal (lowest residual DOC concentration) can be achieved by the combination of high alum dose and low pH (e.g. pH 5).

600 1 500

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maximise DOC removal but maintain acceptable aluminium concentrations was found co be a combination of high alum dose and pH controlled in the viciniry of pH 6.

Alum and ferric chloride are che most commonly used coagulants in Australia. Figure 4 shows results for coagulation of a source water (Supply H in Figure 1) high in DOC and colour using alum and ferric

Journal of the Australian Water Association

water

FEBRUARY 2008 81

technical features

chloride co illustrate the removal of T HM format ion potential for different coagulant doses with coagulation pH maintained at 6.2. The T H M formation potential of the raw water was not reseed prior co creacmenc but was expected co be in the 400 co 600 µg/L range based on che findings shown in F igure 1. From Figure 4, the T HM levels of all created waters were below the NHMRC 250 µg/L guideline value. When compared with the US Environmental Protection Agency 80 µg/L regulatory value (USEPA D/DBP R ule, 2003), some waters created wich che lower alum doses did nor reach chis level whilst all ferric chloride treated samples were equal or below che 80 µg/L value, predominantly due co the lower pH achieved with fe rric chloride and the stronger NOM binding capacity of ferric iron compared with aluminium (Komatsu et al., 2005) .

Are We Measuring the Right DBP?

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Figure 4. Total THM formation potential under different treatment conditions. Doses were applied as equimolar concentrations of the metal ion with respect to al um and coagulation pH was control led at 6.2.

acceptable analytical methods, and occurrence data were only available fo r five of che HMs. H ence che HM regulation was p romulgated only for HAA5. Since chat ti me, analytical standards have become available and data (Robercs et al, 2002; O bolensky and Singer, 2005) has shown rhat the four unregulated HMs can co nstitute from 20-50% of the overall H M content of created drinking water in the

guideline values for individual THM species, although it has also stipulated char coral THMs can be d erived as che sum of che ratio of the co ncentration of each species co its respective guideline value and chat che sum o f che ratios should not exceed 1. For HAAs, che WHO has also sec guidelines o nly for che three chlorinated HMs.

Limited understanding of the health effe cts for individual DBP compounds, analyt ical o bstacles, and lack of water treatment and occurrence data for most non-THM species Mose water ucilicies in Australia monitor for has led the USEPA ro regulate dri nking T HMs and che analytical technique water maximum contaminant levels for che measures che concentrations of all four In Australia, the NHMRC ADWG (2004) su ms of THM and HAA species individual THM species. T he measurement concentrations (USEPA, 1998, 200 3). The also recommends maximum values for che of HAAs is less common and chose u cilicies regulated THMs comprise four species sum of che four T HMs; however, in che chat do monitor HMs generally only incorporating both chlorine and bromine case of the HMs, there are guideline values measure che three fully chlorinated forms sec fo r individual HM species rather than chlorofo rm (CH C13), chat are listed in che ADWG. T he for che sum of che species. Furthermore, bromodichloromechane (CHBrC l2), fo rmation of che different species dib romo chloromerhane (CH Br2CI) and N HMRC has sec guid eline values only for comprising both THMs and HAAs is the th ree chlorinated H M species, b romoform (CH Br3). HMs co mprise a d ependent on a range of interrelated chloroacecic acid (ClAA), d ichloroacecic total of nine species, which include rwo conditions including chlorine dose, NOM acid (Cl2M), and trichloroacetic acid monohaloacecic acids (ClAA and BrM), concentration and character, pH, (Cl3M) . In comparison, che World Health three d ihaloacecic acids (Cl2M, BrClAA temperature and contact time. The presence Organisatio n (WHO , 2006) has sec and Br 2M), and four crihaloacecic acids o f halogen ions such as bromide (Cl3M, BrCl2M, Br2ClAA and and iodide results in conversion Br3M) . In che US, THMs are of these ions co oxidising acids regulated as "coca] T HMs", che O DOC 6 mg/L, Chlorine 12 mg/L 60 chat convert NOM co sum of all fou r brominaced and brominaced and iodinated • DOC 3.1 mg/L, Chlorine 4 .2 mg/L chlorinated species' DBPs. T he extent o f chis 50 concencracions, whereas HAAs ~ conversion is dependent on the are only regulated as HAA5, che 'E conditions identified earlier as .$ sum of five of the nine 0 40 well as che bromide (or iodide) 0.. brominaced and chlorinated C co ncentration and ratio of HM species' concentrations. 0 30 applied chlorine co bromide (or ~ HAA5 includes both E iodide). An example of the monohaloacecic acids, cwo of the 0 impact ofNOM and chlorine LL 20 dihaloacecic acid s (Cl2M and dose on THM speciacion is ~ Br2M), and one of the I in Figure 5. illuscraced crihaloacecic acid (Cl3M ). The I- 10 ~ 0 I n chis water source, remaining four HMs (three conventional treatment removed brominaced crihalo acecic acids 0 nearly half of the DOC (6 mg/L and one brominaced dihaloacecic CHBr3 CHCl2Br CHCIBr2 CHCl3 co 3.1 mg/L) and lowered the acid) were excluded because at chlorine demand of che creace/d the rime che H M regulatio ns water such chat the chlorine Figure 5. Change in THM speciation with change in were first proposed in the US in dose required co achieve a DOC concentration and chlorine dose. 1998, analytical standards,

us.

82 FEBRUARY 2008

Water

,. Journal of the Australian Water Association

,..

residual after 12 days was reduced from 12 mg/L to 4.2 mg/L. This resulted in a significant reduction in the total THM fo rmation potential from 265 ug/L to 14 l ug/L. H owever due to the relatively high co ncentration of b romide ion (0.4 mg/L) it also resulted in a change in the distribution of the T H M species from a predominance of chloroform to a predominance of che brominaced species, b romodichloromechane and dibromochloromechane. Ocher workers have also reported char DBP speciacion was affected by changes in Br to DOC ratio as a result of changes in the character of NOM by removal, alteration by chemical treatment and adsorption (Owen et al., 1998).

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Figure

(R 2 =0.782). T h is is important because research suggests char brominated DBP compounds may be more harmful than their fully ch lorinated counterparts (Bull et al, 200 l , Rich ardso n, 2003). The situation is especially important in Australia where b romide concentrations in the drinking water so urces can be relatively high in so me supplies, and bromine (and iodine) will certainly be present in membrane-desalinated seawater unless specific m easures are taken to reduce their concentrations (although the NOM content should be low) . Recent research has also drawn attention to the occurrence and potential health effects of iodinated byp roducts (Plewa et al, 2004, Weinberg et al, 2002). Thus, furth er insights into halogen substitutio n patterns in drinking water DBP data are important for improving our understanding of DBP formati on, occu rrence, and exposu re in drinking water. T h is information form s pare of the overall goal of main taining public health protection th rough optimised treatment and appropriate regulation and monitoring. The THM speciation patterns ill ustrated in Figure 5 suggest that brominated HM species can be formed to a significant degree during chlorination, and that monitori ng of on ly mono-, di-, and trichloroacetic acid may not accoun t for overall HM formation, especially in waters domi nated by brominated T H Ms. Obolensky and Singer (2005) have shown that, for any sample of chlorinated water, the extent of bromine substitution in any DBP class can be characterised by expressing the molar co ncentration of bromine incorporated in to the various DBP species in that class as a fraction of the total molar halogen concentration for chat class. This ratio is termed the Bromine Incorporation Factor (B IF), an d is defined as shown by Equation 1. T o obtain the BIF fo r any class, the molar concentrations of bromine-contain ing species an d total halogen-containing species are computed for each compound in the class. After summing bromine and total halogen concentrations across all species in the class, BIF can be determined as the ratio between class-sum bromine and class-sum total halogen . All calculatio ns are done on a molar basis.

L L

(species molar cone. )x (species # Br substituents) (Br/) - ~ "·~-----,IX cv.ss (species molar cone.)x (species # halogen substituents)

incorporatio n into THM and HM species, and illustrating differences in dist ribution of species with changing treat ment or disinfection con ditions (Drikas et al., 2003; Boyer and S inger,

2004; Singer et al, 2007). Previous research (Roberrs et al, 2002; Obolensky and Singer, 2005) has shown char the extent of bromine incorporation into th e three d ihaloacetic acids parallels b romine incorporation among th e fo ur T H Ms. Lim iced HM data for eight South Australia treated waters which included the measurement of seven HMs (excluding

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An example of the BIF calculation for T H M species is shown in Equation 2 . BTF (THM) = (BrC'2CH + 2*Br2CICH + 3•Br,CH)/ (3*(C'3CH + BrChCH + Br2ClCH + Br3CH))

(2)

BIF values range from O to 1, with an increase in BIF representing

'll.i:i increase in the fo rmation o f brominated DBPs. BIF has proven to B~ a useful method of representing the extent of bromine

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Journal of the Australian Water Association

Water

... the bolter way

FEBRUARY 200B 83

200 -

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two crihaloacecic acids, dibromochloroacecic acid (Br2 ClAA) and cribromoacecic acid (Br3M)) were available from a specific investigation of water quality and DBP formation undertaken over several months (Holmes and Oemcke, 2002). Comparison of the BIF for the THMs and the dihaloacetic acids calculated from chis data (Figure 6) conformed co che linear relationship expected based on previous work in the U.S (Robercs et al, 2002; Obolensky and Singer, 2005) . In addition, che assump tion was made chat bromine incorporation into che four crihaloacecic acid species cracks bromine incorporation into che THMs, an observation made by previous researchers. As such, che concentration of the two missing crihaloacecic acids can also be determined from che available South Australia data for che four measured THM species and trichloroacetic acid. This assumption enabled calculation of the concentrations of Br2 ClAA and Br3M, which allowed che sum of all nine bromineand chlorine-containing HMs (HM9) co be determined for the available samples. This sum was chen compared co the coca! concentration of the four bromine- and chlorine-containing THMs. Figure 7 is a plot of the paired THM and HM concentrations in che eigh t South Australia finished waters comparing the sum for the three chlorinated HMs in accordance with established guidelines in Australia, and che sum of che nine total HMs, including both the seven measured HMs and che two calculated using the method described above. Two important features are apparent. First, coca! HM (HM9) concentrations, on average, are approximately 60% of che coca] THM concentrations, on a weight basis. Second, and most importancly,

84 FEBRUARY 2008 Water

measurement of only che three chlorinated haloacecic acids represents an average of only 40 -50% of che coral HM concentration formed. This indicates chat measurement of only mono-, di-, and trichloroacetic acid in waters containing appreciable levels of bromide are likely co exclude che HM species chat are che most dominant species in these waters . An indication of che relative importance of these bromine-containing species can be seen by inspecting the distribution among the THM species. If chloroform is a minor T H M species in chlorinated drinking water compared with che ocher THM species, then che chlorinated HM species are also likely co be minor HM species in these waters. Establishing guidelines only for che th ree chlorinated HMs species does not encourage water utilities co determine che full extent of HM formation.

Conclusions Many Australian water utilities use chlorine for disinfection and generally monitor DBPs identified within che ADWG. T he key halogenated DBPs monitored are che four THMs and only the three chlorinecontaining HMs with guideline values in che ADWG. Treatment processes can be optimised co remove NOM, and the Australian water industry has focused on reducing the fo rmation ofTHMs as a surrogate fo r all DBPs, with liccle data available on the concentration of ocher DBPs. However, there is mounting evidence chat brominaced DBPs are of greater heal ch significance than their chlorinated counterparcs. Analysis of limited South Auscralian data confirmed US experience chat the extent of incorporation of bromine inco HAAs parallels chat of bromine incorporation in

Journal of the Australian Water Association

THMs. This indicated chat che coca! concentration of all nine bromine- and chlorine-containing HMs was about 60% chat of the total THM concentration on a weight bas is, and chat che brominated H Ms constituted more chan 50% of che coca! HM concentration. This suggests chat excluding brominated HMs from che measurement of HMs and from the ADWG may significancly underestimate the extent of HM formatio n and public exposure co chis major class of DBPs. This is of particular importance in water supplies co ntaining significant concentratio ns of bromide and where brominaced THM species dominate. With the increased health concerns surrounding brominaced DBPs, ic is important chat Australian water ucilicies investigate and acknowledge the full extent of brominated DBP formation in their supplies, and chat che ADWG include guidance for HMs ocher than the three fu lly chlorinated species.

The Authors Mary Drikas (email: Mary.D rikas@ sawacer.com. au) is the Program Leader, Water Treatment Technology, CRC for Water Quality and Treatment and the Principal Chemise, Water Treatment unit, Australian Water Quality Centre, Private Mail Bag 3, Salisbury, South Australia, 5108, Australia. Philip Singer is the Dan Okun Distinguished Professor of Environmental Engineering in the Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina, Chapel Hill, NC, USA. Christopher Chow is a Project Leader within the CRC for Water Quality and Treatment and Senior Research Scientist, Water Treatment unit, Australian Water Quality Centre. Michael Holmes is che Sensor Research Scientist, United Water Incernacional.

Acknowledgment The authors wish co thank Rolando Fabris and Fiona Fitzgerald for che experimental work and che CRCWQT 2501 project partners for the coordination of the water sampling p rogram.

References Babcock, D. B. and Singer P. C. (1979) Chlorination and Coagulation of H umic and FulvicAcids.j.AWWA., 71, 149 Boyer, T.H. and Singer P.C. (2005) BenchScale Testing of a Magnetic Ion Exchange Resin for Removal of Disinfection ByProduct Precursors. Water Research, 39, 1265-1276 Bull, R. J.; Krasner, S. K.; Daniel, P.A.; Bull, R. D. (2001 ) Health Effects and Occurren e of

refereed paper

Disinfection By-Products; American Water Works Association Research Foundat ion and American Water Works Associarion: D enver,

co,.

Chow, C.W.K., van Leeuwen, J.A., O rikas, M., Fabris, R., Spark, K.M. and Page, 0.W. ( 1999) The Impact of the Character of Natural Organic Matter in Conventional T reatment with Alum. Wat. Sci. Tech. 40(9) 97-104. Drikas, M. , Chow, C.W.K. and C ook, 0. (2003) The Impact of Recalcitrant Organic Character on Disinfection Srability, T rihalomethane Formation and Bacterial Regrowth - An Evaluation of Magnetic Ion Exchange Resin (M IEX") and Alum Coagulation./ Water SRT - Aqua 52(7) 475487 . Holmes, M and Oemcke 0. (2002) Optimisat ion of conventional water treatment processes in Adelaide, South Ausualia, Water Science and Technology: WaterSupply 2 (5-6) 157-163 Komatsu, K., Nakajima, F., Furumai, H. and Miki, 0. (2005) Characterisation of dissolved organic matter (DOM) removed by iron coagulation using spectrofl uorimetry and pyrolysis GC/MS analysis. journal of

Water Supply: Research and Technology AQUA 54(3), 157-163. Liang, L. and Singer P.C.. (2003) Factors

N HMRC/NRMMC (2004), Australian D rinking Water Quality Guidelines, http://www.nhmrc.gov.au/ publications/ synopses/eh l 9syn. hrm Obolensky, A. and Singer P.C. (2005) Speciat ion Patterns Among D isinfection Byproducts Using the Information Collection Rule Database. Environ. Sci. and Technol., 39, 8, 2719-2730 Owen, O.M , Chowdbury, Z.K., Scott Summer, R., H ooper, S.M ., Solaik, G. and Gray, G. (1998) Removal of D BP Precursors by GAC Adsorpt ion . Denver, American Water Works Research Foundation. Plewa, M .J ., Wagner, E.D., Richardson, S.O., Thruston, A.O., Woo, Y and McKague, A.B. (2004) C hemical and Biological C haracrerizarion of Newly Discovered lodoacid D rinking Warer Disinfecrion Byproducrs Environ. Sci. Technol. 38, 47 134722. Richardson, S. D. (2003) D isinfection byproducts and orher emerging conraminants in drinking water Trends Anal. Chem. 22, 666-684. Roberrs M.G , Singer P.C and Obolensky A., (2002) Comparing roral HM and total THM concentrations using !CR dara, JAWWA, 94, 1, 103-114

Influencing the Formation and Relative Oiscribucion ofHaloacetic Acids and

(. LOWARA

T rihalomerhanes in Drinking Water. Environ. Sci. Technol., 37, 13, 2920-2928

Singer, P.C. , Schneider M., Edwards-Brande J . and Budd G.C. (2007) Magnetic Ion Exchange for the Removal of Oisinfecrion By-Product Precursors: Pilar Plant Findings. j.AWWA, 99, 4, 128-139 U.S . Environmental Prorecrion Agency. National Primary Drinking Water Regulations: Oisinfecranrs and Disinfection Byproducts; Final Rule. Fed. Regist. 1998, 63, 69390-69476. U.S. Environmental Prorecrion Agency. Narional Primary Drinking Water Regulations: Stage 2 D isinfectanrs and Disinfection Byproducts Rule; National Primary and Secondary Drinking Warer Regulations: Approval of Analytical Met hods for Chemical Conraminanrs. Fed. Regist. 2003, 68, 49548-49681 . Weinberg, H.S., Krasner, S.W., Richardson, S.O., Thrusron, A.O. (2002) The Occurrence of Disinfection By-Produces (DBPs) ofHeal rh C oncern in Drinking Warer: Resulrs of a Nationwide OBP Occurrence Study; EPA/600/R-02/068; U.S. Environmental Prorecrion Agency, Office of Research and D evelopment, National Exposure Research Laboratory: Athens, GA. White, M.C., Thompson J.D, Harrington G .W., and Singer P.C. (1997) Evaluating Criteria for Enhanced Coagulation Compliance. JA WWA 89, 5, 90 W H O (2006) lmp://www.who.inr/ water_saniration_health/dwq/guidelines/en/

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The Safety of Internal Epoxy Coating • Internally the steel pipe has a solvent free Epoxy bonded coating • Hydraulic advantage with a smooth epoxy finish • Effective against bacteria • W.S.A.A Appraised and recommended as 50 year pl us design life • Corrosion free • Epoxy will handle all types of water qualities • Epoxy is environm entally friendly and safe for drinking water

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line connections to lined sewer pipes, uses a prop rietary blend of silicate resin and an installation process chat allows it to be more quickly installed in a far wider range of non-standard junctions than was previously possible.

Project, che largest recycled water project in che Southern Hemisphere, which will provide 11 0 MGD (400 MLD) of recycled water ro reduce che load on che region's water supply. The plant employs 18-inch diameter MegaMagnu m® reverse osmosis (RO) elements from Koch Membrane Systems (KMS) to reclaim mun icipal effiuent for use as che water supply for cooling rowers at the Swanban k and the Torong power stations.

lnterflow's lnterfit™ - to be shown at the ASTT Conference and Exhibition . It is also stronger, and, importantly in the crenchless technology ind ustry, installation is less disruptive for che community. The Interfic will be joined by the Interpacch™ an advanced type of patch liner used fo r spot repairs in damaged pipelines - and an improved type of house service liner. The company will also be showing and demonstrating an advance in manhole rehabilitation chat allows work to be completed more quickly and practically. Also on d isplay wi ll be op tions fo r renewal of non-round ovoid and box section conduits. The ASTT Conference and Exhibition runs from March 2-3, at the Waterview Centre, H o mebush Sydney. The Conference will feature demonstratio ns of crenchless technology in action.

www.interflow.com.au or tel (02) 9631 2444.

REVERSE OSMOSIS ELEMENTS REDUCE COSTS The Bundamba Advanced Water Treatmen t Plant was commissioned near the city of Ipswich, Queensland, in September of last year The 7.9 MGD (30 MLD) water reclamation system is pare of the Western Corridor Wastewater Recycle

The 18-inch d iameter MegaMagnu m elements are the wo rld's largest com mercially available spiral-wou nd R O elements. These elements are designed to sign ificantly reduce che cost, footp rint and installatio n rime of R O systems. Each l 8by-61 inch MegaMagnu m spiral element used for the project contains 2,800-squarefeec of membrane surface area, compared to 400-square-feec in commonly deployed 8-by-40 inch prod uces. Bu ndamba Advanced Water Treatment Plant (AWTP) Stage lA was awarded to the Thiess Black & Veatch joint venture by the Queensland scare government in early 2007. Stage lA is the first of cwo projects chat make-up che Western Corridor W astewater Recycle Project. The Thiess Black & Veatch joint venture selected a fo u r-train MegaMagnum RO system from KMS for the fast- crack first phase of che water reclamation initiative. Each preengineered, packaged MegaMagnum MM13 train holds 65 membrane elemen ts. Bundamba AWTP Stage l A was com pieced with four trains for a total of 260 memb rane elements in the system. The packaged MegaMagn um MM13 systems enable fas t installatio n and scare-up. I nstallation of the MegaMagnum RO

system began in May of 2007 and the plane became operational in August 2007, three weeks ahead of schedule. "Koch Memb rane Systems' equipment started arriving at the Stage lA site on May 14th, with the lase pieces of equipment arriving in the first week of J une," said Sandy Berman, sen ior project manager at KMS . "Thiess Black & Veatch was contracted by che Q ueensland government ro build, commission and scare-up the plant very quickly, with firm daces required for water production. KMS was able to provide che resources necessary to complete che majority of the scare-up in four weeks rather than the seven chat had been scheduled." O n 2Sepcember 20 07, a dedicatio n ceremony was held at the Bundamba AWTP Stage lA site co mark che official scare-up of the plant. The MegaMagn um RO System is currently performing u p co expectations. KMS has also supplied MegaMagnum systems with a capacity of 9.5 MGD (36MLD) for Stage 1B of the Bundamba plant. When complete, the BundambaAWTP will treat 17.4 MGD (66 M LD ). Based in Wilmi ngton, Mass ., Koch Membrane Systems is a Koch Chemical Tech nology Group, LLC company.

For more information on Koch Membrane Systems and its full line of membranes and accessory products, visit www.kochmembrane.com, or write to info@kochmembrane.com.

UV TECHNOLOGY ENSURES STANDARDS ARE MET Berson UV disinfection equipment is helpi ng che award-winning Flat Creek Water Reclamation Facility (WRF) in Georgia, USA, exceed permit limits fo r faecal ou tput by a significa nt margin. "We installed three Berson medium pressure InLine UV systems over six years ago, adding three more in 2004, and they have performed exactly as expected, with all our faecal samples well below the permit limit," commented Flat Creek's Plane Manager, M ichael West. The Flat C reek WRF recently gained a second place Nation al C lean Water Ace

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FEBRUARY 2008

Water

Journal of the Australian Water Association