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Journal of the Australian Water Association

Volume 34 No 5 August 2007

OPINION AND INDUSTRY NEWS OPINION Water Industry Skills - Cause and Effect DBarnes, President, AWA The AWA You Want to Have TMollenkopf, CEO, AWA My Point of View NFletcher, Emeritus Professor of Physics, University of New England AWA NEWS Includes: RiverBank - Breaking New Ground; Smart WaterMark Working with Water Utilities; Report on the NWC Stakeholder Forum; Climate Activist to Kayak Murray-Darling; Celebrating 'Water for Life' During October AWA EDUCATION Includes: Young Water Professionals (YWP) CROSSCURRENT National Issues and Policy, States, New Reports and Papers, Awards, People in the News AWA MEMBERSHIP NEWS New Members

4 5 6 8 18 20 30

PROFESSIONAL DEVELOPMENT NATIONAL EVENT CALENDAR EVENTS; CONFERENCE REPORTS

32 34

TECHNICAL FEATURES (' ·,1 indicates the paper has been refereed) IRRIGATION Irrigation Versus Ecosystems: What are the Choices? Can we achieve sustainable development of wetlands? CMFinlayson TDS REDUCTION [i) TDS in Sewage: Sources and Trends in Melbourne's West . . /,, / The impacts of trade waste TDS on recycled water can be reduced ~\./ TR Ibrahim, BMeehan, PCarpenter, NCorby PUMPING & PIPELINES Pressure Sewerage Systems: Seminar, April 2007, Melbourne A technology attracting a lot of interest Report by Andrew Chapman and Bob Swinton [I] Improved Cytotoxicity Testing of Products in Contact with Drinking Water Amendment of the Australian Standard {AS/NZS 4020) S Fanok, S Froscio, AHumpage CLIMATE CHANGE [El The Enhanced Greenhouse Effect: Threats to Australia's Water Resources· Part 2: Potential Impacts and Solutions Ableak scenario for southern and eastern Australia ABPittock DESALINATION lll Treatment of Wastewaters by RO: Operating Issues - Part 1 Identifying potential membrane foulants ADavey, RSchumann, KHoehn Tolerance of Marine Life to Desalination Plant Discharges Establishing the site-specific tolerable level of salinity NVoutchkov RECYCLED WATER ~ Risk Management: Bovine Johne's Disease and Water Recycling Quantifying and managing the risk of disease transmission TAnderson WATER SUPPLY AState Water Plan For Western Australia Extensive community consultation and 13 government agencies involved MBlais, HForte

39

44 50

55

59

62 67

71

75

WATER BUSINESS NEW PRODUCTS AND BUSINESS INFORMATION · SPECIAL FEATURES: SEWER SYSTEMS; SLUDGE MANAGEMENT ADVERTISERS' INDEX

80 96

OUR COVER The environmental impacts ofthe saline outfalls from seawater desalination plants are closely scrutinised wherever they are in the world. The paper on page 67 outlines the biologi,cal testing program used in California. In Australia the first big plant was commissioned in Perth early this year and discharges its concentrate into Cockburn Sound via a 1.5 km pipeline and 40 diffuser ports. The mixing zone is less than 3 ha. There is an ongoing program, the most intensive ofany in the world, to monitor the health ofthe receiving water. Our photograph shows the team preparing to launch one of the buoys which transmit physical and meteorological parameters every 30 minutes to the Water Corporations Operations Centre. Photo courtesy of the Water Corporation. Journal of the Australian Water Association

Water

AUGUST 2007 1


~ AWA CONTACT DETAILS • 'Promoting the sustainable ,I' .,;:::::,,. management o1 water Alli!UUAM

J

POSTAL ADDRESS PO Box 388, ARTARMON NSW 1570

EMAIL info@owo.osn.au WEBSITE http://www.owo.osn.au PRESIDENT David Barnes - president@owo .osn.au

CHIEF EXECUTIVE OFFICER Tom Mollenkopf - tmollenkopf@owo.osn.au

CHIEF OPERATIONS OFFICER Ion Jarmon - ijormo n@owo .osn.au

EVENTS Lindo Phillips - 61 2 9495 9914 lphillips@owo.osn.au

MEMBERSHIP INFORMATION AND INQUIRIES Michael Seller - 02 6581 3483 mseller@owo.osn.au

MEMBERSHIP RENEWALS AND CHANGES Membership Team - 1300 361 426 info@owo.osn.au

MEDIA AND MARKETING Jennifer Sage - jsoge@owo.osn.au

SCIENTIFIC AND TECHNICAL INFORMATION Dione Wiesner PhD - 61 2 9495 9906 dwiesner@owo.osn.au

WATER EDUCATION NETWORK Corinne Cheeseman - 61 2 9495 9907 ccheesmon@owo.osn.au

NATIONAL SPECIALIST NETWORK Louro Evonson-6129495 99 17 levo nson@owo. osn. au

AWA BRANCHES: AUSTRALIAN CAPITAL TERRITORY and NEW SOUTH WALES Errin Dryden - 61 2 9495 9908 edryden@owo.osn.au NORTHERN TERRITORY c/ o Ion Jarmon - 61 2 9495 99 11 ijormon@owo.osn.au SOUTH AUSTRALIA Sarah Corey · 6 1 8 8267 1783 so bronch@owo.osn.au QUEENSLAND Kathy Bourbon - 61 7 3397 5644 owoq@owo.osn.au TASMANIA & VICTORIA BRANCH c/o Rochel-onn Mortin - 61 3 9235 1416 tosbronch@owo.osn.au vicbronch@owo.osn.au W ESTERN AUSTRALIA Coth Miller - 0416 289 075 cmiller@owo.osn.au INTERNATIONAL WATER ASSOC IATION, AUST. (IWAA) c/o Tom Mollenkopf · tmollenkopf@owo.osn.au

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

COPYRIGHT AWA Waler Journal is subject to copyright and may not be reproduced in any format without wri tten permission of AWA. To seek permission to reproduce Waler Journal material emai l your request to: jsoge@owo.osn.au

2 AUGUST 2007

Water

Journal of the Australian Water Association ISSN 0310-0367

Volume 34 No 5 August 2007

AWA WATER JOURNAL MISSION STATEMENT 'To provide a 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 eighl times per year: February, March, May, June, August, September, November and December EDITORIAL BOARD Chairman: FR Bishop BN Anderson, TAnderson, CDiaper, GFinlayson, AGibson, GA Holder, BLobza, 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.ou AND journol@awo.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 ore tabled at monthly editorial board meetings and where appropriate are assigned to referees. Referee comments will be forwarded to the principal author for further action. See box on page 8 for more details. 2. OPINION, INDUSTRY NEWS, PROFESSIONAL DEVELOPMENT Jennifer Sage, jsoge@awo.osn.au Articles of 1000 words or less 3. WATER BUSINESS Brion Rauh, Notional Sales & Advertising Manager, Hallmark Editions brion.roult@halledit.com.au Water Business updates readers on newproducts and associated business news within the water sector. ADVERTISING Brian Rault, National Sales & Advertising Manager, Hallmark Editions Tel: 6138534 5014 (direct), 6138534 5000 (switch), brian.rault@halledit.com.au Advertisements are included as an information service to readers and are reviewed before publication to ensure relevance to the water environment and objectives of AWA. PURCHASING WATER JOURNAL Single issues available@$12.50 plus postage and handling; email dwiesner@awa.asn.au BACK ISSUES Water Journal back issues are available to AWA members at www.awa.asn.au PUBLISHER Hallmark Editions, PO BOX84, HAMPTON, VICTORIA 3188 Tel: 61 3 8534 5000 Fax: 61 3 9530 8911 Email: hallmark.editions@halledit.com.au

Journal of the Australian Water Association


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• The National Water Commission's report 'Using Recycled Water for Drinking Purposes' provides an overview of the national and international experience of indirect and direct potable re-use. This report will complement the national guidelines for the use of recycled water for drinking purposes currently being developed. • The Chairman of the National Water Commission, Ken Matthews, and Commissioner Peter Cullen today released the findings of the second stage of the baseline assessment of water resources for che National Water Initiative, 'Australian Water Resources 2005'. • Water restrictions are "not sustainable" or adequate in themselves to meet the projected shortfall between population growth and demand in the cities in particular accordi ng to a report prepared by water experts for che J une 2007 meeting of the Prime M inister's Science, Engineering and Innovation Council. • Dr Rick Evans's report for Land and Water Australia 'The Impact of G roundwater Use on Australia's Rivers' cautions chat we have often double counted water as surface and groundwater, when they are usually closely linked and are really only a single source. This has exacerbated shortages, but can cake many years ro emerge. • The Final Report of the Prime M inisterial Taskforce on emission trading co operate at a national level from 2010 has been released. U ntil a nation emission reporting scheme is established, interim schemes are being established by the states. The water industry is among entities with a responsibility co submit data though these schemes.

AWARDS • The Australian finalists of the 2007 National and International T hiess Riverprizes are: the Lake Macquarie Improvement Project; Maroochy Shire Council's River Recovery Initiative; NSW Murray Wetlands Working Group; and Greening Australia's River Recovery Programme. The international finalists come from Austria, Canada, China and New Zealand. • To encourage the development of young professionals in the irrigation industry, the Australian National Committee on Irrigation and Drainage is again offering a travel fellowship award of $10,000 for a young scientific achiever in irrigation research and development. V isit the AN C ID website fo r details. www.ancid. org.au • Singapore's national water agency, the Public Utilities Board (Singapore PUB), has been awarded the 2007 Stockholm Industry Water Award fo r its excellent water management system combining a good policy framework with innovative engineering such as water recycling.

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PEOPLE in the NEWS • Sean McKinney takes up National Sales Managers role with Phoslock Water Solutions. Tel: 0433 989 123. Email: smckinney@phoslock.com.au • Natalie Foley has been appointed as Cardno's Business Unit Manager, Water Supply and Sewerage for Cardno, based in their Brisbane Head Office. Tel: 07 3369 9822. cardno@cardno.com.au

• Graham Dooley is stepping down from the role of Managing Director of United Utilities Australia. Kevin Starling has been appointed Regional Director and will also assume the role as MD of UUA. Details Stan Boath stanboath@uua.com.au • Roberta Brazil has been reappointed Chair of Land and Water Australia for a further two years. Contact details from robin.pash@daff.gov.au • SKM Chief Executive Paul Dougas has just announced the appointment of Tim Boyle as global Chief Operating Officer. Terry Petersen has been appointed General Manager, Infrastructure, with Graeme Booth becoming Regional Manager, NSW.

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• Chris Davis, retired CEO of AWA, has now left AWA and will be joining the Institute for Sustainable Futures at UTS, as Sustainability Partnership Development Manager. Until he scares at ISF in August, his email address is cdavis3@bigpond.ner.au • Ray Borg, formerly with Western Water, is taking up the position of Director Water for H yder Consulting in Melbourne • Andy McPharlin, Service Delivery Manager for SA Water in Mount Gambier, has been awarded the Public Service Medal in that stare for three decades of work for water resources management. Andy.mcpharlin@sawarer.com.au

• Prof Nancy Millis AC has been given che ATSE's Lifetime Contribution Award for her long-lived contribution to microbiology and water. • Emeritus Professor P L Darvall AO FTSE, former Vice Chancellor of Monash University and director, Melbourne Water Corporation, was recognised for his service to education and as an engineering academ ic and researcher • Paul Hackney has returned to Sydney after working for SA Water in Adelaide for 3 years, to become Senior Water Scientist at NSW Water Solutions. paul. hackn ey@commerce.nsw.gov.au

• Robyn McLeod, fo rmerly Executive Director, Major Projects Division, Department of Sustainability in Victoria, has joined KPMG as D irector, National Water Group based in Melbourne. rmcleod@kpmg.com.au

• ProfJurg Keller has been elected for a second term as Chairman of the International Water Association's Australian National Committee (IWAA), and Dr Therese Flapper is the new V ice Chairman. IWAA is actually a branch of AWA and members are encouraged to hold joint membership in the two associations www.awa.asn.au and www.iwahq .org

• Chris Godfrey, previously with Babcock & Brown P ower, has joined Veolia Water Australia as CFO. Email: chris.godfrey@veoliawater.com.au

• David McGill has been appointed Business D evelopment Manager of Rico Pipe Industries, contact david.mcgill@ricopipeindustries.com.au

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• Steve O'Brien from URS has won the fi rst AN COLD Scholarship fo r Young Professionals in 2007. T his award has been introduced to allow young professionals to increase their skills and knowledge in particular fields of dams engineering by international study tour. The subject of Steve's scholarship is "Seismic Assessment of Appurtenant Structures at D ams" . • Doug Miell has left the NSW Irrigators' Council to get married and live in the USA. Doug's m easured approach to hot water issues will be missed.

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Water

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AUSTRALIAN WATER ASSOCIATION NATIONAL EVENT CALENDAR 2007 & 2008 Accurate at time of printing. For branch events, please visit the AWA website www.awa.asn.au and/or check with your local branch contact for up to date information. Date

Event

Location

Contact

Phone

3 Aug 07

AWA NSW Heads of Water Gala Dinner

Sydney NSW

Errin Dryden

02 9495 9908

3 Aug 07

AWA NSW Drinking Recycled Water Half Day Forum

Sydney NSW

Errin Dryden

02 9495 9908

16 Aug 07

AWA Vic Annual Dinner

Melbourne, VIC

Rachel-Ann Martin

03 9235 1416

21-23 Aug 07

Rainwater and Urban Design 2007

Sydney NSW

Tour Hosts Pty Ltd

02 9265 0700

21 Aug07

AWA One Day Seminar- Recycled Water Guidelines

Adelaide SA

Diane Wiesner

02 9495 9906

22Aug07

AWA One Day Seminar- Recycled Water Guidelines

Perth WA

Diane Wiesner

02 9495 9906

27 Aug07

AWA One Day Seminar- Recycled Water Guidelines

Brisbane QLD

Diane Wiesner

02 9495 9906

29-31 Aug 07

AWA NSW Water Treatment Workshop

Port Macquarie NSW

Errin Dryden

02 9495 9908

3-6 Sep 07

10th International Riversymposium 2007

Brisbane QLD

Emily Smigrod

07 3034 8230

6 Sep 07

AWA One Day Seminar- Recycled Water Guidelines

Sydney NSW

Diane Wiesner

02 9495 9906

13-14 Sep 07

AWA DBOOT Desalination Master Class

Adelaide SA

Diane Wiesner

02 9495 9906

17-18 Sep 07

AWA DBOOT Desalination Master Class

Sydney NSW

Diane Wiesner

02 9495 9906

19-21 Sep 07

AWA NSW Engineers and Operators Regional Conference

Coffs Harbour NSW

Errin Dryden

02 9495 9908

23-27 Sep 07

IWA I Ith World Congress on Anaerobic Digestion (AD I I)

Brisbane QLD

Jenny Marsden

07 3855 37 11

26 Sep 07

AWA One Day Seminar - Recycled Water Guidelines

Melbourne VIC

Diane Wiesner

02 9495 9906

11 - 13 Oct 07

AWA VIC Regional Conference

Traralgon, VIC

Rachel-Ann Martin

03 9235 1416

13-17 Oct 07

WEFTEC.07 80th Annual Technical Conference and Exhibition

California, USA

WEF Association Services

1-703-684-2552

19 Oct07

South Australian Water Awards

Adelaide SA

Sarah Carey

08 8267 1134

21 -27 Oct 07

National Water Week

National

Jennifer Sage

02 9495 9916

24-26 Oct 07

AWA NSW Trade Waste Conference & Exhibition

Sydney NSW

Errin Dryden

02 9495 9908

Perth WA

Linda Phillips

02 9495 9914

28 Oct- I Nov 07 IWA 2nd ASPIRE Conference and Exhibition 7-8 Nov 07

Worry Wastes in Water

Sydney NSW

Diane Wiesner

02 9495 9906

9-11 Nov 07

AWA Q LD Regional Conference

Sunshine Coast QLD

Kathy Bourbon

07 3397 5644

26 Nov 07

AWA NT Regional Conference

TBC,NT

Errin Dryden

02 9495 9908

28-29 Nov 07

AWA Master Class - Water Infrastructure II

Sydney NSW

Diane Wiesner

02 9495 9906

4-6 Feb 08

IWA Young Water Professionals Conference

Brisbane, QLD

Sandra Hall

07 3346 7209

Linda Phillips

02 9495 9914

Wayne Castle

02 9495 9921

30 Mar - 2 Apr 08 Water Efficiency 2008; )rd National Water Education Conference; Surfers Paradise QLD Ist National WICD Conference. 5-7 May 08

Enviro Convention & Exhibition

32 AUGUST 2007

Water

Journal of the Australian Water Association

Melbourne, Vic


CLIMATE CHANGE AND AUSTRALIA'S WATER RESOURCES: SHARING IDEAS ON THE WAY FORWARD

Water 1or a Healthy Country NAHONAl IHSEARCH

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FLAGSHIPS

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Water and climate change scientists fro m arou nd the nation will gather in Canberra in November for a symposium offering an ind epth an alysis of che hydrological impacts of climate change on Australia. T he Hydrological Consequences of Climate Change symposium b rings together leading researchers co discuss how co better understand the consequences o f fu ture climate change on Australia's water reso urces. T he two-d ay meet ing, from Novem ber 15 co 16, is spo nsored by the CSI RO's O ffice of the C h ief Execu tive Science Team, and suppo rted by the Austral ian C limate C hange Science Program, the National Water Commission and Land and Water Australia. H eld at the CSIRO D iscovery Centre, th e symposium will cackle key questions, such as: • W hat are the future climate predictions for Australia? • What are the hydrological consequences of these futur e climate proj ections fo r Australia? • W hat technology/techniques have the greatest potential co imp rove the accuracy of hyd rocl imacological prediction immed iately and in fi ve co 10 years time?

wca11ter

AWA

IEffIT<eDf f/lty

AUSTR A LI A N WATER ASSOCIATION

--------

2008

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~~~ The aim of the Aust~a; an Water Association's biennial National Water Efficiency Conference is to achieve a common understanding on the best way forward for a national approach to regulations for improving water efficiency and developing some perma~ t controls over the use of water. The next conference will be held in 2008.

Call for abstracts closes 10 August 2007 Sponsors ip and exhibition opportunities are available

• What are the merits o f better in tegrating hydrological prediction in co climate modelling and what is requi red co ach ieve such in tegratio n? Water resources will be o ne of the most im pacted sectors from climate ch ange, says Symposium organiser D r Ian Prosser, Science Di rector fo r the W ater fo r a H ealthy Co untry Flagship. In fo rmation shared throughout the cwo days will in clude newlydetermined Intergovernmental Panel on C limate C h ange (I PCC) predictions fo r Australia, a d etailed assessment of the way in which climate change is likely co change th rougho ut chis century. Also discussed will be the impacts o f climate change on the El Nino-Souchem O scillatio n (ENS O) and resulting effects o n Australian precipitatio n, with the possibili ty of longer and more frequent El Ninos, lead ing co longer and more severe droughts. "Under an extended drought, there may simply no t be en ough water co go around, so techniq ues which allow us co include the possible future impacts of climate change on water availability will be of paramount impo rtance," Dr Prosser says. However, h e says there are many new technologies which may be useful in determining exactly how climate change is going co im pact Australia's water resources. " Remote se nsing of rainfall and soil moisture has ch e ability co improve the accu racy of our models co a great degree," he says . "These improvements along with the coupling of h ydrologic and climate models represents a massive improvement in our abi lity co forecast. This meeting will certainly help us work cowards achieving the goal of d etermining how climate change is going co impact Australia's water resources." Dr Prosser says che symposium is ch e first opportunity fo r hyd rologists and climate modellers co come together in chis way for an in- depth analysis of chis research. "The Flagship is facilitatin g chis initiative as pare of ics collaborative approach on the issue, which includes work between che Flagship and collaborators such as the South Ease Australian C limate Initiative, che Indian Ocean C limate Ini tiative, and the National Water Commissio n. " Expressio ns of interest are being sought from early career scientists co concribuce co a poster session, co be sponsored by Land and W ater Australia . Researchers undertaking pose graduate studies or within five years o f completion of a PhD are invited co express their interest in presenting a poster by submitting a title and abstract of no more than 200 words by email co Helen.Beringen @csiro.au, cc co Ian.Prosser@csiro.au by July 31, 2 00 7. D erails of the symposium , including the program are available on h ttp ://www. csiro.au/ evencs/ H ydroC onseq uences.h cml. Registration s, which are lim ited co 13 0 places, are filli ng fast, and can be made online.

Helen Be1·ingen

THE PROFESSIONAL DEVELOPMENT AGENDA August 2007 - February 2008 The next few months offer lots of oppo rtunities for AWA members and their colleagues co cake up some professional skills upgrading specially targeted ac changes co regulatory requiremen ts or meeting knowledge gaps faced by the water industry.

Enquiries. Ph: (02) 9413 1288, Fax: (02) 94131047, Email: efficiency08@awa.asn.au

34 AUGUST 2007

Water

Journal of the Australian Water Association

All these professional development seminars, confe rences and master classes are listed under the Events C alendar on the AWA web sire http://www.awa.asn.au/events/


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• Recycled Water Guidelines Seminars (Phase 1): These seminars are for non- potable application of the reuse guidelines for irrigation, industrial processes and playing field watering. Speakers take participants step-by-step through these new guidelines using case studies to show how they are applied. All major cities will host a seminar between 9 August and the end of September. A seminar in Hobart will be run at a later date. • DBOOT Desalination Master Classes -Adelaide 13-14th September and Sydney l 7-18th September, 2007. Nikolay Voutchkov, a highly regarded engineer from USA with lots of hands-on experience in design, construction and management of seawater desalination plants, is the principal speaker for a "how to do it" class. Nikolay's skills will be complimented by Professor Tony Fane, Australia's own membrane specialist and other specialist engineers. • Two Day Seminar "Worry Wastewaters II" - Sydney November ?-8th 2007. This seminar is specifically designed to showcase some of the latest wastewater technologies and their application to real life projects where industries and business are facing major challenges in dealing with production wastewaters high in nutrients, salt, BOD and other pollutants which pose disposal problems. Pulp and paper, dairy, abattoirs, piggeries, chicken processing and ocher rural industries are all chose facing such issues. • Water Infrastructure Master Class - Sydney 28-29th November 2007 . The water industry is being called upon to rapidly answer a lack of critical infrastructure. What are the pitfalls of the various types of project management models? How does one best arrange to finance such expensive projects - and construct

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• Great networking opportunities • A multi-discipline exhibition focusing on innovation • Day registrations to accommodate specialist

"W"lVIE Environmtnl Busintu Mt dh1

them quickly? Public-private sector partnership or alliance contracting - which best suits smooth delivery and minimises risk? • Conference Special: Accounting for Carbon in the Water Industry- 27-28th February 2008, Sydney. Yes, emissions trading and carbon accounting will be required of all water utilities, local government authorities and those contractors servicing the water industry. This special conference is intended to bri ng together industry planners and managers to share ideas and experiences on how best to capture and manage carbon related emissions data, renewables to reduce usage and offsets most suitable to adopt.

All of the above are designed to meet calls on the industry and the skills of industry professionals. As well, local state branches of AWA hold their regular technical sessions and regional conferences which are excellent in bringing members together to swap experiences and trouble shoot problems. We look forward to seeing more of you at these local and national events as we all try to respond to the current demands on our industry.

Queries on all of the above can be directed to Diane Wiesner on 02 9495 9906 or dwiesner@awa.asn.au.

AWA TWO DAY SEMINAR: WORRY WASTEWATERS II 7- 8 November 2007 Crowne Plaza Hotel, Parramatta

WORRYII WASTEWATERS AWA's Worry Wastewaters II (registration brochure enclosed within the Journal) is designed to showcase some of the various treatment methods and technologies developed specifically to address problems faced by manufacturers and processors in the dairy, meat, piggery, cereal and other processing industries dealing with difficult process wastewaters which risk breaching discharge conditions. Paper manufacturers, paint and printing must also employ new wastewater treatments to achieve sustainability goals within their operations. The program for the seminar is varied in the treatment methods covered - biological treatment, wetlands, membranes, anaerobic digestion - which are applied either alone or in combinations dependent on the industry and the situation. Hence it is packed with case studies rather than theory, showing what works, why and how. The end product of treatment in each instance is purified water char can be reused on site, in process or withi n plant operations. The added benefit of engaging in this exercise in sustainable reuse for the industry concerned is chat by recycling former wastewater, the volume {and cost) of treated water drawn from the public system is reduced - an added cost benefit to the business The keynote speaker Peter Macintosh, Director, QED-Occtech Services Limited, spoke at Worry Waste I in 2006 and feed back indicated chat his practical, hands-on engineering experiences were what people wanted to hear about. Peter has over 25 years experience in the design, construction and management of wastewater treatment systems for industry. The venue for this two day seminar is conveniently located in the geographic heart of Parramatta at Crowne Plaza Hotel, 30 Phillip Street. This is a very practically focused session with plenty of interesting contributions from engineers, researchers and project consultants on adapting the more conventional treatments to real life situations and circumstances. We hope to see lots of members there!

36 AUGUST 2007

Water

Journal of the Australian Water Association


AWA WATER & HEALTH SPECIALTY Ill CONFERENCE Sydney, 23-24 May 2007 Opening Address by David Barnes, President AWA

The quality of drinking water and human health is well documented. There is a wide range of water borne pathogens chat have the potential to transmit illn ess from one person co the next. The role of faecal contamination n spreading cholera was clearly shown in the mid nineteenth century. The resu ltant efforrs to provide treated water supplies, is a major factor in reducing mortality races. In face, the engineering contributions of provision of safe drinking water and improved housi ng condi tions have made significant impacts upon general health and life expectancy. Hence the role of water quality as a factor in the maintenance of human health is well established. The circumstances in which the water has co be managed are curren tly changing. This reflects a series of facto rs, several of which are interlinked, including: • A period of prolonged drought in southern Australia, generally linked to a change in climate • Development of technologies chat offer the potential co achieve desired water quality using processes chat are not conventional municipal practice e.g. membrane processes

• Public expectation that includes improved environmental quality, access to recreational facil ities, expectation of inputs to decision making processes and widespread access to information To identify the challenges chat face rhe water industry in protecting human health it is worthwhile to examine the previous current and probable future water supply conditions.

Previous The basis of water supply was a single use of water. Preferably collecti ng raw water from an undisturbed upland catchment e.g. at or over the hills behind our major ciries. The raw water collected: could then be provided with simple low cost treatment chat may not be more complex than screening and disinfection. Th is represented a low heal ch risk due co che high quality of che raw water - in face the specification of the protected catchments was included in guidelines for water supplies. Even supplies based upon river waters could produce drinking water quality with simple coagulation/ flocculation/ fi Icratio n/ disinfection based treatment plants. Particularly in coastal communities the water would have a si ngle use - raw water collection, treatment, distribution and use within che town or city, sewage collection, treatment and discharge of eilluen t to an estuary or the sea. Generally the different fo rms of water within che urban environment - water, sewage and storm water - were kept separate. In Sydney, we had che Metropoli tan Water Sewerage and Drainage Board, the title reflecti ng rhe separate management of the diffe rent types of water. Current The unprecedented activity in the water sector and che intense public interest and

debate about water reflect several changes chat have occurred in recent years. Water storage levels are at historically low points - chis has lead to changes in the volume, quality and accessibility of dam storage and groundwaters. There is active competition for water from different water users - industry, power generation, agriculture, municipal supplies and to maintain environmental quality The impact of discharges on water quality at points of downstream abstraction has increased with general population and economic growth and low surface and groundwater flows. Catchments char have provided raw water are for more developed than when they were established. For example groundwater supplies under the city of Perch and che location of Prospect Reservoir almost in the centre of the Sydney conu rbation. Hence water quality collected from the catch ments is of lower quality than in previous years.

Near Future A series of changes are currently occurring in che water used as raw water and the consequent requirements for treatment to protect the quality of supply. T he changes vary with location in some places changes have already occurred, in ochers there are a range of activities ranging from planning through co construction. The shifts include: • Desalination of sea water to provide a proportion of the water supply. The use of sali ne water as the raw water provides a constantly available source and has become feas ible with advances in membrane technology. • Indirect potable reuse has been a topic of local debate and tends co polarise opinions. This use of efflu ents as raw water has been implicit in some of the downstream river intakes for many years. The current

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Journal of the Australian Water Association

Water

AUGUST 2007 37


professional development II:

drough t conditions has moved forward several initiatives ro use effluents as a source water for potable and non potable applications. This tend co indirect potable reuse is gathering momentum and it is highly likely chat in the next decade we will accept chis form of reuse as normal practice and wonder at the intensity o f che debate. • As a drought response there has been increased installation of water tanks within urban areas. Obviously many people have and do rely upon water ranks for all of their domestic water needs. However che use in urban areas was discouraged until recently and, while the collected water is primarily for non potable purposes, the potential for human co nsumption is not negligible. Hence chis means char water with little or no treatment and no direct quality regulation is becoming part of the water supply mix. • T he development activity within water catchments will continue with increasing pressure co allow access co scored water for recreational purposes. T his is common in ocher countries but again alters the raw water risk profile. • There will be an increased race of deterioration of assets due to climate change. This means the recurrent coses will increase and the poten tial for water loss and contamination increase.

Consequences The sequential changes from the low risk high quality raw water sources are moving the water qualicy/healch equation. Water has co be sourced from a range of raw water qualities chat can include very high sale concentration and very high pathogen concentrat ions. Similarly che segregation of water within the urban

environment will not be valid. The harvesting of urban scormwater, which occurs locally in rainwater tanks, is being implemented from urban catchments in cities such as Singapore. Treated effluents p rovide a reliable source of water t han can be reliably converted co potable standard. Whilst ocher social pressures mean that public access co water reservoirs will further modify water quality. The consu mer will also be subject co change. T he supply of a single high quality water for all municipal purposes is changing. Dual water supplies with potable and non potable quality are a feature of recent develop ment. The non potable supply could be from a range of sources - effluent stormwater, rainwater - and hence will be supplied at different chemical and microbial quality depending upon the source. T hese changes have implications for the associated institu tional arrangements with the reliance upon single (postage stamp) pricing of water supplies less defensible on economic and financial grounds. T his means that there are multiple and variable risk p rofiles for the supply of water. These will need co be managed within the context of the raw and supply water quality. T he consequence of the more complex operating regimes mean chat so me organisations are better positioned co manage the risks. More remote locations chat may have a greater need for water generally have less capacity to manage risks.

Challenges Moving Forward As with all problems, the first step cowards a solutio n is co properly understand the issues, causes, effects and consequences. The Water and Health Specialty Co nference foc uses mainly on these technical aspects. The technical understanding then has co be converted into sensible, appropriate and viable regulation and the associated control regime. Th is may mean customised requirements co reflect raw water qualities and water usage. Plus management of the water supply by prescribed organisations chat have the capacity and expertise co meet the conditions. The skill levels of all personnel within the water cycle will need co rise. The whole of the water cycle and its infrastructure will co be act ively managed as a single integrated system. The certification and associated training of personnel that operate water treatment and distribution systems will need co be upgraded and implemented.

4-6 February 2008

For more information contact:

UQ Centre

YWP2008 Organising Committee

The University of Queensland

Cl- Dr Pierre Le Clech UNSW

Brisbane, Australia

Website: ywp2008@awa.asn.au

Jointly Organised by

AWA ~

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Advanced Wastewater

~ Management Centre

Of QuEENSUINO

www.ywp.org.au 38 AUGUST 2007

water

Journal of the Australian Water Association

The protection of health will require 'buy in' by the community. Generally water professionals have been slow co participate in public debate, have tended to respond rather than lead opinion and have tended co shun community participation in decision making. Several of the water/health interfaces necessitate active community involvement including a scormwater management and harvesting, use of water from rainwater tanks and the general plumbing and use of water from several sources. Returning co the initial strong con nection between water quality and human health, the Newcastle Morning Herald (13 August 1894) reflected 'Doccors acquire renown by the cure of diseases induced by unhealthy surround ings and there ought co be quit as m uch praise accorded co people who exert themselves for the bringing about of a sanitary state of things, and thus minimising the necessity fo r the curative agencies of the professional healer'. Clearly the second wave of 'people who exert themselves' is now needed to p roduce the same health outcomes but within a more difficult matrix of risks.


IRRIGATION VERSUS ECOSYSTEMS: WHAT ARE THE CHOICES? C M Finlayson Abstract The recently compiled Comprehensive Assessment of Water Management in Agricu lture and the 2005 Millennium Ecosystem Assessment both foreshadow, over the next 50 years, increasing use of water for food and fibre, wich resultant degradation of valuable rivers and wetlands. These are likely co occur in Australia as well as on a global scale.

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T his paper discusses some issues chat need co be considered if we are co make better use of our wetlands fo r che long-term and co balance our water uses.

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Introduction Developing and managing water resources co help end poverty and hunger and feed an additional 2 billion people, while reversing ecosystem degradation, presents a significant global challenge, as outlined in che recently compiled Comprehensive Assessment of Water Management in Agriculture. Th e dilemma is chat more people will require more water for agricul ture, yet che way in which people use water in agriculture is globally one of the most important drivers of ecosystem degradation. T his is especially so for wetlands char provide many valuable ecosystem services fo r people. The Millennium Ecosystem Assessment reported in 2005 char che expansion of agriculture and water regulation were the key drivers of ecosystem degradation globally, threatening the resource base upon which many people depended. The Assessment fur ther showed chat rivers and wetlands have borne the brunt of degradation; chis is very evident in Australia with river regulation and water abstraction along with vegetation clearing and infill ing of wetlands havi ng inexorably changed che landscape. Given che extent of ecosystem degradation and water regulation globally it is feared chat the equation fo r fu ture food and water supply and demand globally may not add up. More water is required for poverty alleviation, for food production, for cities and industries, yet more water regulation threatens che provision of the ecosystem services chat directly and indirectly underpin che livelihoods and well-being of many people. T he scenarios are complex, for example, we know chat globally many fisheries have been degraded through che regulation of rivers in order co obtain water supply fo r energy and irrigation and for urban use, and yet we still regulate rivers and divert water from valuable fisheries. There are vociferous arguments when ic is realised chat within many river basins there simply is not enough water - it has been allocated, or even over allocated. This scenari o occurs in many countries; it is well known in Australia where drought exacerbates comm unity debate over water management. The Comprehensive and Millennium Ecosystem Assessments both recommended changes in che way we do business. Yesterday's approaches in support of agriculcure and water regulation have not been fully effective in reducing poverty; instead they have led co a new sec of issues - increased competition, environmental degradation, and water scarcity. New approaches are required co solve today's water and food production problems. These may not be chat elusive.

Figure 1. Cultivated systems (areas in which at least 30% of the landscape is cultivated) in 2000 (derived from the Millennium Ecosystem Assessment).

Can we achieve sustainable development of wetland.sf

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water

AUGUST 2007 39


Global Assessment of Ecosystems

Table 1. Water management in agriculture and the Millennium Development Goals

The key messages developed by che Millennium Ecosystem Assessment are outlined below before considering che challenges people face in making decisions about investing in water for food, ecosystems and livelihoods.

(From the Comprehensive Assessment of Water Management in Agriculture).

i) Over the past 50 years, humans have changed ecosystems more rapidly and extensively chan in any comparable period of rime in human hiscory, largely co meet rapidly growing demands for food , fresh water, timber, fibre and fuel. ii) The changes chat have been made co ecosystems have concribuced co substantial nee gains in human well-being and economic development, but have b een achieved at growing coses in che form of the degradation of many ecosystem services . . . . . . and the exace rbation of poverty for some groups of people. iii) The degradation of ecosystem services could grow significantly worse during the firs t half of chis century and is a barrier co achieving the Millennium Development Goals. Ecosystems globally have been transformed as a co nsequence of changes in land cover and land use (Figure 1). These changes have resulted in substantial gains in human well-being through the production o f food, but there are increasing questions about whether or not chis is sustainable given the loss of ecosystem services, including fisheri es and ochers such as che regulation of erosion, floods and local climates. This is very apparent when considering wetland ecosystems - che situation is well known co Australia's irrigacors who have witnessed salinisacion and water logging associated with broad-scale changes in the landscape as water flows have been transformed and th e native vegetation cleared. The imperative has been to produce food for both local consumption and export - the question is nor whether we need more food , it is whether or not the real coses are being counted; have we gone coo far and how can we do things differently? The Comprehensive Assessment has attempted co answer such questions within the context of achieving the UN-established Millennium Development Goals (Table 1).

Millennium Development Goal

Role of water management in agriculture

Goal l Eradicate extreme poverty and hunger

Increase agricultural production and productivity to keep up with rising demand and maintain affordable food prices for the poor; improve access to factors of production and markets for the rural poor.

3 Promote gender equality

Goal

a nd empower women

Enhance equitable access to water and thus the ability to produce food.

Goal 4 Reduce child mortality Goal 5 Improve maternal health Goal 6 Combat HIV/ AIDS, malaria and other diseases

Contribute to better hygiene a nd diets, particularly through the appropriate use of marginal-quality water and the integration of multiple water-use approaches into new and existing agricultural water management systems, including domestic and productive functions.

Goel 7 Ensure environmental sustainability

Integrate the principles of sustainable development into agricultural water development to reverse the loss of environmental resources.

Goal 8 Develop a global partnership

Involve the diverse range of practitioners, researchers, a nd for development decisionmakers in the preparation of water management actions .

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Figure 2. Intercepted co ntinental runoff a nd reservoir storage (derived from the M illennium Ecosystem Assessment).

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Agricultural Demand for Water and Pressures on Wetlands The push for greater agricultural production has resulted in more land being converted from natural co cultivated systems that now cover one quarter of the Earth 's terrestrial surface (Figure 1). Ac che same time in order co provide water for cultivated systems, natural water regimes 40 AUGUST

2007

Water

Developed countries

Africa

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Figure 3. G lobal irrigated areas (derived from information suppl ied by FAO and presented i n the Comprehensive Assessment of Water Management in Ag riculture).

Journal af the Australian Water A ssociation


technical features

have also been altered. In response to increasing demands for water, large numbers of reservoirs have been constructed (Figure 2); rhe number of large dams in rhe world increased fro m 5000 in 1950 to more than 45,000 at present. Reservoi rs now store water for 30-40% of irrigated land and generate 19% of global electricity supplies. Regulation of the water regime to chis extent has caused significant degradation of wetlands/rivers, both inland and coastal. Dams have resulted in rhe fragmentation and modification of aquatic habitats, disrupting water flows, altering the flow of matter and energy, and establishing barriers to migratory species. An assessment of 227 major river basins globally showed 37% were strongly affected by fragmentacion/alcered flows, 23% moderately, and 40% unaffected. In many instances the trend for further land conversion and water regulation and/or increased food production continues, as shown by the trend for irrigated areas in developi ng countries and globally (Figu re 3) . Projected increases in water withdrawals for irrigation for 2025 range from 4-24% with che lower value being due to optimistic projections about increases in rain-fed areas and an assumption char increased foo d trade will play a major role in overcoming demands for more food globally. Producing more food also means using more water, and on past trends, continued environmental degradation of wetlands through furt her conversion and/or water regulation! T he amount of water used for producing a range of food prod uces has been calculated by various authors and despite some variability in che figures each person is held responsible for convening 2000-5000 litres of liquid water to vapour each day, compared to 2-5 litres for drinking and 50200 litres fo r other household tasks. T hese figures illustrate the importance of food production in rhe water cycle. As consumption patterns conti nue to cha nge, with, for example, increased demand for higher water-demandi ng grain-fed meat prod uces, the demand for water will intensify. Over the next 50 years ch e demand for food crops is projected ro grow and food production to intensify. Demand for water will therefore inevitably increase, with water withdrawals in developing countries increasi ng significantly and chose in industrial countries declin ing. Many countries or basins are expected to suffer water scarcity, whether from physical or econo mic constraints (Figure 4). Substantial increases in the efficiency of water use and management may lessen che

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Physical water scarcity

D Economic water scarcity

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Figure 4. A reas of physica l and economic water scarci ty (from the Comprehensive Assessment of Water Management in Agriculture) .

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Figure 5. W ater scarce basins in 2000 and 205 0 (from the Comprehensive Assessment of Water Management in Agricultu re).

future demand fo r water, although achieving efficiencies may be made more complex by che consequences of global climate change. Further development of irrigation may also result in further physical scarcity of water in many basins (Figure 5), even if economic scarcity declined. Under che scenario shown in Figure 5 some 2.6 billio n people may be living in water scarce basins by che year 2050. Scenarios involving large increases in irrigation also highlight the need for more dams and increases in water withdrawals by some 50-60% with potential large impacts on rivers and wetlands and alterations in the ri ming and variabili ty of flows. Scenarios involving increased productivity of rain-fed agriculture could reduce such

impacts, bur further diversion of rainfall and runoff from aquatic ecosystems is expected to exacerbate rhe impacts caused by dams and river regulation. The issue of intercepting and storing large volumes of off-channel water is already contentious in Australia.

Wetlands - Extent and Change Estimates of rhe global extent of wetlands differ significa ntly and are highly dependent on the definition of wetlands and on the methods used for deli neating chem. The estimated extent of weclands globally derived from national inventories is approximately 1,280 mi llion hectares, which is considerably higher than previous estimates. Nevertheless, this figu re is

Journal of the Australian Water Association

Water

AUGUST 2007 41


technical features

considered an underestimate, especially for southern America and for certain wetland types (such as intermittently flooded inland wetlands, peatlands and artificial wetlands) where data were incomplete or not readily accessible. The estimate for Australia of 24 million hectares (<2% of the global total) is based on an incomplete and inconsistent information source. T he extent of wetland loss and degradation is widely recognised, but not often supported by quantitative data. More than 50% of specific types of wetlands in parts of North America, Europe, Australia, and New Zealand were lost during che twentieth century, bu c extrapolation of this estimate to wider geographic areas or to ocher wetland types is fraught with inaccuracy. There is insufficient in formation available on the extent of all wetland types to document the extent of wecland loss globally. Much of the loss that has been recorded occurred in the northern temperate zone during the first half of the twentieth century, whereas many tropical and sub -tropical wetlands, such as swamp forests, were lost or degraded over the second half of the century. Clearing and drainage, often for agricultural expansion , and increased withdrawal of freshwater are the main reasons for the loss and degradation of inland wetlands such as swamps, marshes, rivers, and associated flood plain water bodies. By 1985, an estimated 56-65% of inland and coastal marshes (including small lakes and ponds) had been drained for intensive agriculture in Europe and North America and 27% in Asia. Agriculcural systems and practices have exerted a wide range of mostly adverse impacts on inland and co astal wetlands globally. Both the extensive use of water for irrigation and excessive nutrient loading associated with the use of nitrogen and phosphorus in fertilisers have resulted in a decline in the delivery of services such as freshwater and some fish species. The introduction of invasive alien species is now considered to be a major cause of extinction of native freshwate r species.

8 120----------------------------

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40.------,,------.-----.-----,-----~---~ 1970

1975

1980

1985

1990

1995

2000

Note: The Index incorporatn data on the abundance of 656 te,rntrill 1pecin, 323 lre1hwater apecln, and 287 marine 1pecin around the world. While the Index fell by aome 4096 between 1970 and 2000, the terrntrial Index fell by about 3096, the frnhwatw index by about 6096, and the marine Index by about S()9(,_._

------------J

Figure 6. Th e Living Pla net Index (from the Millennium Ecosystem Assessment based on information from WWF and UNEP-WCMC) .

and 200 0 - more drastic than chat fo r terrestrial or marine species (Figure 6). Even in the case of more poorly known wetland fauna, such as invertebrates, assessments show chat species in these groups are significantly threatened with extinction. A summary of information on the status of wetland species is shown in Table 2.

The Future - Concluding Comments In concluding, a few key statements are presented as a basis for further analysis and consideration when discussing management responses. These introduce some issues chat need co be considered if we are to make better use of our wetlands for che long-term and to balance our water uses: • I ncreased pressure from increased population and con sumption of food will translate to increased pressure on wetlands and further loss of wetland species and ecosystem services -can we afford to lose further wetlands and their ecosystem services, many of which are provided without cost to society as a whole?

nature and result in more environmental degradation, and possible persistence of poverty and food insecurity - the manner in which we do business needs to be reassessed and placed within the context of reducing poverty and en suring sustain able agriculture; • I mproving irrigation efficiency may make gains for food production, but may not enhance the surrounding environment as in many basins little water is being wasted leakages from irrigation systems can be captured, but with likely adverse affects on groundwater recharges or flows chat currently occur back to wetlands; • Improving productivity through improved crop yields through irrigation may result in increased use of fertilisers and agricultural chemicals and increased pollution and eucrophicacion of many types of weclands - the balance between intensification and extensification of agriculture still needs to be explored as it may not be a panacea for better environmental outcomes;

• Increases in water productivity and upgrading of rain-fed food production hold • Business as usual will result in more a lot of promise for increasing food There is also evidence of a rapid and competition between food production and production and could occur continuing widespread given better governance, policies decline in many populations and institutions - che social of wetland-dependent Table 2. Condition of wetland vertebrates globally (derived from dimension for en suring species, including mollusks, the Millennium Ecosystem Assessment). sustainability and poverty amphibians, fis h , reduction cannot be Condition Vertebrate group waterbirds, and some underestimated. mammals. An index of the 20% extinct or threatened Waterbirds As a final comment, the trend in vertebrate species 30% in decline (especially dolphins, porpoises ... ) Mammals followi ng is proffered . Can we populations shows a 20% threatened or extinct Fish (freshwater) achieve sustainable development continuous and rapid 30% threatened (not all are aquatic) Amphibians of wetlands - can we put our decline of 50% in Turtles 50% threatened concepts into practice and freshwate r vertebrate 45% threatened Crocodiles develop wetland resources and populations between 1970

42 AUGUST 2007

Water

Journal of the Australian Water Association


conserve rhem ar rhe same rime? Is ir possible to develop wetlands without further running down the resource and rhe very p rocesses and interactions char support the wetland? An integrated approach is need ed for managing land, water, and ecosystems. Much of the discussion above relates ro a global scenario of increased p ressure on water resources and balancing societal o utcomes. Australia is nor immune to chis pressure - we face rhem when making choices about the allocation of our water as demand from urban uses increases and climate variability and drought imposes more stress on our water reso urces and infrastructure. As a major food exporting country our choices will have international ramifications and will b e influenced by international conditions.

The Author Dr Max Finlayson (email m.finlayso n @cgiar. org) is a Pri ncipal Researcher in Wetland Ecology and T heme Leader for Water Management and rhe Environment ar the Internacional Water Management Insrirure (IWMI) based in Colo mbo, Sri Lanka . He is currently President of W etland Internario nal's Supervisory Council and past-Chair of the Ramsar W etland Convention 's Scientific and T echnical Review Panel. H e has been involved with several global assessments, e.g. The Millenium Ecosystem Assess ment, rhe Third Assessment Report on C limate Change, and most recently rhe Comprehensive Assessment of Water Management in Agriculture. Previously he was Director of rhe Environmental Research Institu te of rhe Supervising Scientist with the Federal D epartment of Environment and H eritage, in D arwin, NT. In late 2007 h e moves to Charles Srurr University in AJbury, NSW, as Professo r for Ecology and Biodiversity.

Bibliography Balmford, A., A. Bruner, P. Cooper, R. Cosranza, S. Farber, R.E. Green, and others. 2002. Economic Reasons for Conserving Wild Nature." Science 297, 950-53. Falkenmark, M ., Finlayson, C.M. & Gordon, L. (coordinating lead authors) 2007. Agriculture, water, and ecosystems: avoiding the costs of going too far. In Molden, D. (ed.), Water for food, water for life: a comprehensive assessment of water management in agricul ture. Earthscan, London, UK, pp. 234-277. Finlayson, C.M . & D'Cruz, R. (coordinating lead authors) 2005 . Inland water systems. In Millennium Ecosystem Assessment, Volume 2 Conditions and Trends . Island Press, Washington DC, USA. Finlayson, C.M ., D'Cruz, R. & Davidson, N.J . (coordinating lead authors) 2005. Ecosystem services and human well-being: water and wetlands synthesis. World Resources Institute, Wash ington DC, USA. Kura, Y., C. Revenga, E. Hoshino, and G . Mock. 2004. Fishing/or Answers. World Resources Institute, Washington D .C. Millen nium Ecosystem Assessment. 2003. Ecosystems and Human Wellbeing: A Framework for Assessment. Island Press, Washington D .C. Millennium Ecosystem Assessment 2005. Millennium Ecosystem Assessment Synthesis Report. Island Press, Washington D .C. Molden, D. (ed.), 2007. Water fo r food , water for life: a comprehensive assessment of water management in agriculture. Earthscan, London,

UK. Foley, ] .A., DeFries, R., Asner, G.P., Barford, C., Bonan, G ., Carpenter and others 2005 . G lobal consequences of land use. Science 309, 570-574. Revenga, C., J. Brunner, N . H enniger, K. Kassem, and R. Payner. 2000. Pilot Analysis of Global Ecosystems, Freshwater Systems. World Resources Institute, W ashington, D .C.

Journal of the Australian Water Association

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AUGUST 2007 4 3


~fereed paper

TDS IN SEWAGE: SOURCES AND TRENDS IN MELBOURNE'S WEST T R Ibrahim, B Meehan, P Carpenter, N Corby Abstract

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A significant impediment to reuse of recycled wastewater in western Melbourne is the high Total Dissolved Solids (TDS) co ncentration in the sewage flowing into the Western Treatment Plant (WTP) at Werribee. There are three sources of TDS in the western sewer system; trade waste inputs (industrial processing and neutralisation), domestic inputs and infilcracion from groundwater sources. T h is paper presents an investigation of the TDS characteristics for the influent at WTP and of a sample of domestic wastewater catchment from a residential sewer. The average flow-weighted TDS concentration at WTP was 913 mg/ L and average flowweighted TDS concentration in the domestic sewer line was 3 19 mg/L. The average total load calculated at WTP was determined to be 444 tonnes/day but it was estimated chat the TDS load at WTP from C ity West Water residential customers was only about 37 tonnes/day. The paper suggests two strategies for reductio n of trade waste TDS: use of buffering capacity to reduce neutralisation impacts and diversion of peaks.

40

Introduction Water reclamation, recycling and reuse are now recognised as key components of water and wastewater management in all areas of Australia. In light of the lase 8 years of drought the vulnerability of Victoria's water reso urces has been brought sharply into focus. In response, the Victorian Government set a target to recycle 20% of Melbourne's treated effluent by 2010 (D SE 2003). Melbourne is a city of over 3 million people (ABS 2004-05) and currently consumes 480,000 ML of potable water per year (D SE 2004, MWC 2003) . Residential use acco unts for 60% and industry accounts for 28% (MWC Nov 2003, MWC 2003). Melbourne produces approximately 350,000 ML per year of domestic and industrial wastewater (MWC Nov 2003). There are three retail water companies in Melbourne. City West Water (CWW), Yarra Valley Water (YVW) and South Ease Water (SEW) and one wholesaler: Melbourne Water Corporation (MWC) . 44 AUGUST 2007

water

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Figure 1. Hourly W TP Influent Flow, 2005. City West Water is responsible fo r the larger proportion of industries located in Melbourne. and consequently is responsible for the largest percentage of trade waste being discharged into the sewer system, rhe majority of which is discharged to che Melbourne Water's Western Treatment Plane (WTP) (ca 500 ML/d). The Western T reatmen t Plane's sewage treatment process is by a huge lagoon system and currently some effluent is used on-site for irrigation , and a proportion further treated and exported as recycled water, for horticultural, recreational and domestic customers. (Poon et al. 2006).The balance is discharged into four separate outlets in to Pore Phillip Bay under strict Environmental Protection Authority (EPA) license agreements O ne of the major factors limiting the reuse of recycled water is the concentration of Total Dissolved Solids (TDS). As a result, the Victorian Government, CWW and MWC have developed the Sali nity Reduction Strategy, which was introduced with the aim of reducing the sale content in recycled water by 40% by 200 9 (DSE 2004). TDS is a measure of the coral amount of d issolved solids in water. I t is the combined content of all sol uble inorganic and organic

The impacts of trade waste TDS on recycled water can be reduced.

Journal of the Australian Water Association

substances which are present in a molecular or ionised form. Inorganic compounds include sulfates, phosphates, chlorides, fluorid e, bicarbonates, carbonates and nitrates of calcium, sodium, magnesium, potassium and aluminium. The organic compounds include organic sales, humic and fulvic acids, and sugars. Organic TDS is largely broken down by conventional wastewater treatment processes. Therefore che contribut ion chat organic TDS has on the total TDS in the effluent is relatively small (TWACC 20 04). Essentially there are three sources of TDS in the western sewer system: trade waste inputs (industrial processing and neutralisation), domestic/commercial inputs and infiltration fro m groundwater sources. I c has been est imated that industries contribute between 40-50% of this TDS (DSE 2004), but with limited data available on sewage characteristics there was a clear need co obtain accurate inflow data on the western Melbourne sewage system in order co be able co investigate st rategies to manage the amount of TDS entering the sewage system through these three sources.

Estimation of Inputs An intensive sampling program was conducted co characterise raw sewage inputs at WTP. A sampling site immediately prior co the first lagoon was chosen co collect raw sewage hourly for two weeks between 16th co 23 rd of March 2005 and 4th co 11th of May 2005. Two composite samplers were


technical features refereed paper

used each consisting of 24 one litre collection bottles. Samplers were set at 10:00am and run for 24-hours. 250 mL was taken every 15 minutes during a 1-hour period, giving a 1-hour composite sample of one-litre. Forry-four parameters were analysed which included standard wastewater parameters such as pH, acidity, alkalinity, total dissolved solids, ammonia, sulphide and a suite of heavy metals. All parameters expect pH and electrical conductivity were determined in a NATA registered laboratory according to standard methods fo r analysis of wastewater (Clesceri et al. 1999) . A permanent flow monitor installed on the main trunk sewer was used to obtain the flow races. In general, the flow of wastewater entering the Western Treatment Plant tends to follow a diurnal pattern as shown in Figu re 1. T he flow is low during the early pare of che morn ing. Aro und 2.00 pm it increases sharply and peaks between 3.00-6.00 pm. Since ic cakes approximately 8-12 hou rs (MWC 2002) for the sewage to flow to che WTP ic is consistent with daily domestic routines (i.e. morning showers, fl ushing of toilets and laundry). Boch sampling weeks had minimal rainfall, therefore there was little or no impact from rainfall on the actual flow from domestic and industrial sources. T he average daily flow into the WTP over the two-week sampling duration was 486 ML/day. Over the diurnal period the TDS differed considerably as shown in Figure 2. Fluctuations over the day are shown, with the highest recorded concentration at 1800 mg/L and the lowest at 300 mg/L. The average daily flow-weigh ted concentration over che two-week sampli ng program was 913 mg/L. The EPA Guidelines fo r Wastewater Reuse recommend chat (EPA 1996), " ... it is desirable that the total dissolved solids of the wastewater are less than 1000 mg/L and preferably less than 500 mg/L." As shown in Figure 2 the levels entering WTP are generally greater chan 500 mg/L and often greater chan 1000 mg/L.

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T he TDS loads presented in Figure 3 were calculated using the measured flow rate and the hourly composite TDS concentrations. The TDS load varies considerably throughout che day and shows the same diurnal trends as the co ncentration (Figure 2). Based on che observarions a possible explanation of these trends and distinctive load peaks could be due to accumulation of high TDS industrial effluents in the sewer system during low flow periods and then at times of high flow these substances flus h down the sewer system causing high concentration spikes at WTP. The average

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Figure 3. Hourly TDS Load from W TP Influent for sampling weeks l ( 16-23 March 2005) and 2 (4- 11 M ay 2005).

daily load was determined to be 444 tonnes/day during the two-week sampling period. It was determined form the results analysed chat 81 % of the total TDS was inorganic and the remaining 19% organic.

Domestic Inputs Unlike industrial trade waste discharges, a domestic household is not restricted in the quality of wastewater discharged to che sewer system. T he major sources of TDS from domestic households are through the use of laundry produces, cleansing chemicals, soaps, strong chemical disinfectants and strong acids and alkalis (Patterson 1998). Minor sources ofTDS also include faeces and uri ne, cooking and food preparation (Patterson 1998). Domestic sewage was monitored hourly for 5 days in February 2006 where a suite of parameters were analysed. The sampling site chosen was a wee well located on Garden Avenue, Keilor, free from trade waste. T he site had a total of 1194 properties connected to che sewer line where 1128 are residential and 66 non residencial. Samples were collected and analysed as described earlier for WTP and were taken from a pump well which was operated on a level concroller. Once the level reached a height of 2 metres, one of the pumps would run and continue co pump until the level in the well reached a height of 1 metre. Measurements of the level of wastewater in the well were

obtained from the pu mp station's Supervisory Control and Data Acquisition (SCADA) at CWW. These depths were used co determine the volume of sewage passing through the wee well in any give hour. Domestic sewage volume entering the sewer system fo llowed a diurnal pattern as shown in Figure 4. In the morning and evening periods the flow was at its highest. The morning peak probably corresponds co residents preparing to go to work/school and in the evening the flow starts co increase at times residents would be returning home. The lace night minimum flow period of approximately 5 hours corresponds co residents sleeping hours. The daytime flow shows a small decline corresponding to residents' working hours. During the sampling period there was minimal rainfaJI therefore not influencing the diurnal flow. The average daily flow was calculated co be 507 kl/day. With 1194 properties within the sewer line region the per capita daily discharge was 425 L/day per property. Using the city wide average 2.5 5 people per property che average discharge per person was 166.7 L/day. Figures 5 and 6 show the diurnal TDS trends for the concentration and load over the 5 day domestic sampling period. There was little difference between weekdays and weekends. There is a low T DS concencracion period between midnight to 6 am corresponding co residencs sleeping

Journal of the Australian Water Association

Water

AUGUST 2007 45


technical features

~

TDS reduction hours. The average daily flow-weighted concentration was 3 19 mg/L and average daily load was 162 kg/day. The percentage of inorganic and organic TDS in the domestic wastewater determined from the results analysed were 72% inorganic and 28% o rganic. The average TDS load calculated per residential property in the sampled area was 135 g/day. Based on the load calculated per property in the sampled area, rimes rhe total of CWW residential properties, the extrapolation estimates a discharge of 37 tonnes/day ofTDS into the WTP. Figure 7 illustrates rhe percentage of CWW residential TDS load entering WTP, only 8.3% of the total.

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To determine if neutralisation even ts can be reduced or elimi nated, it was suggested char the buffering characteristics of the sewer wastewater could be utilised. Titration curves for alkalinity and acidity were determined for the WTP influent and three

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Neutralisation of a waste stream prior to discharge causes an increase in TDS levels in the sewer system. Sodium hydroxide is the most common reagent used in acid neutralisation. bur in a few cases magnesium hydroxide is used. By eliminating or reducing neutralisation then the amount of salts and consequently the levels ofTDS will be decreased.

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TDS Reduction Strategies Trade waste industries have specific discharge guidelines. The allowable pH discharge range is between pH values of 6 and 10. These discharge limits were set to prevent risks to the public, workers, sewer infrastructure and the environment. In 1995 the Trade Waste Acceptance Advisory committee (TWMC) reviewed the current discharge limits to sewer. In the absence of a driver for change it was recommended that no change would be made (TWMC 1995). Theoretically, broadening pH discharge limits could increase the in-sewer evolution of ammonia or hydrogen sulphide.

refereed paper

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Figure 6. Hourly Domestic TDS Load. incoming acidic/alkaline industrial waste streams before neutralisation. Tirrarions were also carried our on the WT P influent using the industries' discharges as ritrants in order to determine if the sewage has enough buffering capacity to absorb low/high pH trade waste inputs without significant changes in the overall pH.

The titration curve illustrated in Figure 8 shows a sample of 60mL of WTP sewage influent titrated with an acidic trade waste at pH 3.52. The titration curve shows that 4 rimes the volume of the industrial waste stream can be discharged into the sewer without the pH of the mix dropping below the TWMC pH value of 6. This showed

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46 AUGUST 2007

Water

Figure 8. Experi mental and simula ted titration curve of a 60ml W TP influent titrated with an Industry waste stream pH of 3 .5 2.

Journal of the Australian Water Association


technical features

that the sewer system has the capacity to absorb untreated acid ic inputs with little change in the overall sewer pH.

of TDS occurring during the peak period further reducing the final T DS load in recycled water.

Also shown in Figure 8 is a simulated titration curve together with the actual experimental titration curve of industry wastewater into the average WTP influent. The simulated titration curve was calculated from the individual acidity/alkalinity titration curves of the WTP influent and the industry waste stream prior to neutralisation and su bsequent discharge. T he experimental and simulated curves closely fo llow the same trend wh ich d emonstrates that the model can be used to manage industrial d ischarge co nd itions for untreated wastewater while maintaining sewer pH levels. This experiment was based on the characteristics of the influent from WTP . Ir should be noted, however, that the characteristics o f individual sewers from ind ustrial zones throughout Melbourne's Western Sewage System are currently unknown. T herefore, further data at different rimes of the day and differen t days of the week is requ ired.

Diversion Another possible strategy fo r the reduction of TDS is the d iversion of the sewage flow at WTP at the highest TDS periods. As shown in Figure 9 there is a distinctive peak of h igh TDS load and the major inorganic ions during the mid to late afternoon. During the 15.0 0 co 18.00 period an average of 22% of daily TDS loads was reco rded during the two week sampling period. A diversion strategy at WTP co a suitable sacrificial land site, or to a separate lagoo n system, could result in a significant reduction in the TDS of treated effl uent sched uled for re-use. Online monitoring of electrical co nductivity (EC) could be used to determine high and low TDS flows and be used co manage the d iversion. In additio n, industries with high T D S discharges could be regulated co discharge at certain rimes thus en hancing the percentage

Conclusion T he suitability of wastewater reuse optio ns nor only depends on economic factors, location and volume available, but more importantly on the chemical and biological p roperties in the wastewater. C urrently the reuse of effluent at WTP is restricted by the high TDS levels especially sodium salts present in the wastewater. T he results presented in this paper show that the average daily TDS fl ow-weighted concentration at WTP was 9 13 mg/Land the average d aily TDS load was 444 tonnes/day over the two sampling periods. The domestic average daily TDS flow-weighted concentration was 319 mg/L and the average daily TDS load from a sample catch ment was 162 kg/day over the sampl ing period. This extrapolates to a total for households in the CWW residential area of about 37 tonnes/d ay of TDS. Two strategies have been described to reduce the amount ofTDS in the infl uent at WTP . The mod el used co generate the simulation described above has the poten tial to manage industrial discharge conditio ns for wastewater withou t significant change to the overall sewer p H. By altering the p H discharge limits trade waste customers could reduce the amount of neutralisation chemicals used to correct the pH , thus reducing the amou nt ofTDS entering the sewer system. The d iversion strategy at WTP could be further invest igated as either a short-term reductio n option until ocher T DS reduction measures at sou rce begin co rake effect, or even a permanent system ..

Acknowledgments We would like co than k the continuous support from C ity West Water, the School of Applied Sciences RMIT and Melbourne Water. T h is project was undertaken as a PhD study, one of a number of student projects

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Figure 9. Ma jor Ions and TDS 17-18 March 2006.

involving the Memorandum of Und erstanding between RMIT University and City West Water. Refer co Meehan, B (2005) Water 3 1, No 8, December 2005, pp 31-34

The Authors Trisha R Ibrahim is a PhD student under Associate Professor Barry Meehan and Dr Peter Carpenter at the School of Applied Sciences, RMIT University, GPO Box 247 Melbourne 3001 Australia, trisha.Ibrah im@rmic.edu.au, barry.meehan@rmit.ed u.au, perer.carpenter@rmit.edu. au . Nigel Corby is Cleaner Production Consultant at City West Water, Locked Bag 350, Sunshine 3 020 Australia, ncorby@cirywestwarer. com.au.

References ABS. (2004-05). Regional Population Growth Australia (32 18.0). Canberra: Australian Bureau of Statistics. Clesceri, L. S., A. E. Greenberg, and A. D. Eaton (ed.). 1999. Standard methods for the examination of water and wastewater, 20th ed . American Public H ealth Association, Washington, D.C. DSE. (2003). Green Paper/or Discussion: Securing our Water Future. Ease Melbourne (VIC): Depart ment of Sustainability and Environment. DSE. (2004). Victorian Government White Paper: Securing our Water Future Together. East Melbourne (VIC) : D epartment of Sustainability and Environment. EPA. (1996). Guidelines for Wastewater Reuse: Publication 464: Environment Protection Authority Victoria. MWC. (2002). Western Treatment Explorer. Melbourne (VIC): Melbourne Water Corporation .www.melbournewater.com.au MWC. (November 2003). Environment

Improvement Plan, Western Treatment Plant. Melbourne (VIC): Melbourne Water Corporation. MWC. (2003) . Recycled Water Handbook. Melbou rne (VIC) : Melbourne Water Corporation. Patterson, R.A. 1998. Household Solutions to End-of-line Re-use Problems. In Proceedings 11 t International Water Services Association - Asia Pacific Regional Conference "Integrating the Urban Water Cycle" Sydney. 1st-5th November, 1998. pp 578-585. Poon, P., K. Keegan, et al. (September 2006) . "UV Disinfection for Class A Water Recycling." Water: 56-60. TWAAC. (1995). Recommendations on

Temperatttre and pH for Trade Waste Discharged into the M elbo11rne Trunk Sewer System: Repott No. 4. Melbourne: T rade Wasre Acceptance Advisory Committee. TWAAC. (2004) . Total Dissolved Solids

Discharged into Melbo11rne's Sewerage System: Interim Report. Melbourne: Trade Waste Acceptance Advisory Committee.

Journal of the Australian Water Association

Water

AUGUST 2007 47


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technical features

pumping & pipelines

PRESSURE SEWERAGE SYSTEMS Seminar, April 2007, Melbourne Report by Andrew Chapman and Bob Swinton • Designing the installation to use less land and locating the pump to avoid possible fu ture development on the block.

The Pressure Sewerage Seminar, sponsored by ' us' -Utility Services, attracted a larger than expected number of delegates with nearly 100 people in attendance. Nor only did the presenters share their experiences and knowledge bur delegates joined in answering questions as well as asking them. O bviously chis is a technology attracting a lot of interest, and rhe current major players are happy to share their 'learnings'. The major users to dare are Melbourne's South East Water, with flat, high groundwater, terrain, and Yarra Valley Water with both steep undulating terrain and flat basaltic areas. Sydney Water has numerous systems, in coastal, mountain and country areas.

Andrew then listed all the known applications throughout Australia and New Zealand.

SE Water Experience Greg Mann has been involved in PSS since the first installation of the system in SE Water in 2000. In SEW's experience the main drivers have been the elimination of sewer easements in backyards, flexibility in design and minimisation of environment impact. Despite the seeming simplicity of the system rhere are challenges:

Installations David Cox, WSAA, noted char rhe first system was installed in South Australia in the lare l 970s as a development of their STEP (septic rank effluent pump system), and ir is still running. He then outlined the current situation in the development of the WSAACode. It aims to provide a reliable, robust and constantly evolving system to meet customers' needs and ensure that future engineers build on hard-won experience.

David Moore of SE Water noted that it was easy to operate and user friendly, particularly the digital version, with hyperlinks to clauses, drawings and search facilities. SE Water has formulated a supplementary company manual providing guidance on such matters as purchase specifications and product appraisal.

Andrew Chapman: General Observations

With respect to engineering these can be summarised as: • Interfaces with the conventional system • Modelling and design of PSS • Managing odour and air • Back up and recovery (e.g. from power outages)

Their first projects were Tooradin, Warneet and Cannons Creek, all on flat, waterlogged coastal terrain. He summarised their initial comparison of the options (gravity, vacuum and pressure), what they had learned and then reviewed their performance.

Tooradin option analysis Engineering factors:

• Training of staff for a new operating regime

• Installation issues: PSS had the smallest pipe size required (PSS 63/90/125 PE, versus Gravity 225/150/1 00, Vacuum 80/100/150), the shallowest depth for pipes (PSS I.Om, Gravity 3 -4m, Vacuum 2-3m) and shortest time for construction (PSS 4, Gravity 10, Vacuum 9 months)

On a more general note there are:

• Financial evaluat ion:

• Design for hydraulic flows, capture of grey water, issues on drought, variable climate for the hydraulic point of view

• H ealrh issues and environment issues • Customer's issues, e.g. cost of installation and operation. e.g. rhe householder is required to pay ca. $20/yr for electricity. • Who owns the pumps

- Capex: Vacuum is 8% higher and Gravity is 40% higher than PSS. - Opex: Vacuum is 70% higher and Gravity is 75% higher than PSS - NPV: Vacuum is 73% higher and Gravity is 70% higher that PSS

• H ow to address issues of power supply, outages, alarms

Performance of current system

• What to do if our of power for several days

• 0 & M issues higher than expected, but

Pressure sewer systems (PSS) offer rhe benefit of lower cost of network construction, do not need grades and with near zero I/I, there are lower sewer flows. They are generally used for backlog sewerage where there is a high cost of servicing, but other applications are for low density residential development, remote community faci lities and large industrial/ commercial lots

• How to manage solids and fats

• Customer issues • Pipe and fitting fai lure

A technology attracting a lot of interest.

• Land issue (ownership) : e.g. PSS uses land in the customer's backyard fo r the pump and rank, so how does the authority access the backyard for services.

50 AUGUST 2007 Water

Issues at T ooradin: mainly infancy failures

• Trade waste: e.g. how to handle pumps, laundry or large storages

• Storage volumes

• How co adopt to green energy: carbonneutral as possible

• Alarm noise

Journal of the Australian Water Association

• Poor outage response (brown outs)

However, overall, it has just met expectations for maintenance frequency and costs.


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ITT Engineered for life


technical features

meter, time delay relay on alarm circuit, trafficable location, vandal resistance, flashing light, stator selection • Design tools for property audits, customer management and database system, street main setouts, hydraulic analysis software, service history database, after PC service structure • Project management & design skills are different from gravity sewerage system engineering, e.g. intensive community interface for on-property works is essential • Establishment of correct loading parameters is essential • · T he hyd raulic analysis muse be developed for the system parameters. DON'T use a generic solution. Australian and US conditions are different and therefore design parameters must be different • Understanding of how a pressure sewer system actually performs and where the performance boundaries really are is viral data to feed into the design process. In summary the main point made was char each situation is unique and rhe designer must determine whether pressure sewer actually is the right solution. He was backed up by Steven French of SE Water, who stated that PSS has some limitations and risks which need co be carefully addressed during planning/design. His very detailed presentation covered hydraulic modelling, flow and pressure profiles, selection of the correct pump and control systems, downstream infrastructure such as bypasses, booster station wells, and emergency valve placement. He noted that simultaneous recovery after a power outage could lead to instantaneous overload, both electrical and hydraulic. One solution was to install different timers on individual pumps to stagger their re-scares.

Normal Flows Vs Power Outage Recovery Shem Macdonald ofYarra Valley water has been involved with a large green-fields development on a flat basaltic area north of Melbourne. H e discussed what benefits, if any, there were for looping in pressure sewer networks. The following were observations made, using a hydraulic modelling example: Benefits of looping: • Greater scope to reduce pipe sizes possible CAPEX reductions • Greater operational flexibility - can divert flows following bursts or blockages • Lower maximum and average system pressures 54 AUGUST 2007

water

• Energy savings as less head pumped • Life expectancy of pump possibly increased? Disadvantages of looping: • Two way flows? • May lead to accumulation of fats/sediment in low flow sections of pipe? • Longer detention times • Additional costs - shut valves, loop pipe lengths In summary, a case by case assessment was strongly recommended. W hat may work for o ne area may not necessarily work for another.

Steven Theodorlis of MWH focused on the modelling process, making an interesting point in the advantages and disadvantages of applying water modelling software in comparison to sewer modelling software. Water modelling packages are adequate for pressure sewer, as they are fast, and provide robust results for pressure sewer systems and pump operation. However, water modelling packages can' t model gravity components, or inflow/infiltration Sewer/Drainage hydraulic modelling packages do allow fo r inflow/infilrracion; however, they are generally slower, subject co instabilities. In summary, if pressure sewer systems and combined systems (combined gravity and pressure) become a more feasible option in the future and become more popular, a modelling package which can cater for chis would be highly recommended.

Pump Units Currently there are three major suppliers: • E-One • Aquacech (Barnes Pumps) • Mono With the expansion of the market, not only in Australia but overseas, they are all developing better systems. Locally, Mono Pumps Australia have had the benefit of the partnership with US (Utility Services) and Steve Watt, Mono Australia Engineering Manager, outlined the derails of the control systems which have been cooperatively designed. Pressure protection is needed since pumps are capable of producing pressure above the ratings of piping and equ ipment. Mono has chosen "Current Sensing" over other pump protection methods, such as thermal overload, pressure sensor, high slip pump. Ir has the advantages of being simple, cost effective, can be integrated to the controller and has proportional control. The sensor is not exposed to sewerage, and it also

Journal of the Australian Water Association

provides motor protection. The disadvantages are che need for repeatable pump performance, but Mono pumps provide chat consistently. The system has been integrated with a diagnostic unit so chat the pressure cur-off point can easily be adjusted. In event of a trip, the pump remains off for five minutes, then cries again.

Operation and Maintenance Gary Grogan (SE Water) backed up by a DVD from 'US', summarised their major issues over the past five years. Maintenance issues relate to blockages, motor assemblies, power supplies and vandalism but overall there have been relatively few issues with PSS system. Most were infancy issues. The introduction of the PSS has resulted in operation crews requiring training in mechanical and electrical components of the network and che requirement of carrying more equipment to be able to carry out required remedial works. (US has built a specially equi pped vehicle co deal with PSS rather than conventional sewer maintenance). The key message was to reduce the customer interface as much as possible with the use of telemetry and the need to educate customers and call centre staff. They experience many 'false alarms, particularly after power outages, so If a customer phones they ask the customer co wait for one-two hours and co phone in again if the problem persists. The inclusion of 24 hour storage on each property has enabled SE Water co manage response times and contain most co business hours. Educating staff has enabled more information co be passed on che customer and therefore rather than sending a crew our immediately once an alarm is activated we can work with the customers ro determine the reason for the alarm activating and whether or not we are required on-site immediately or if the call out can wait for a more suitable time.

Conclusion As discussed above, this is another option for sewerage, which should be considered, particularly for waterlogged terrain, steep terrain, environmentally sensitive sites and greenfield developments with unknown potential. Ir is applicable for backlog and infill. It has its own problems but the WSM Code is endeavouring to systematise design .


technical features refereed paper

IMPROVED CYTOTOXICITY TESTING OF PRODUCTS IN CONTACT WITH DRINKING WATER S Fanok, S Froscio, A Humpage Abstract The Australian Water Quality Centre (AWQC) routinely conducts resting in accordance with Australian and New Zealand Standard 4020 'Testing of products for use in contact with drinking water'. Cyroroxicity resting is included as part of the Standard to determine if product extract waters exert detrimental effects against mammalian cells. In this study the MIT (-(4, 5 dimethylthiazol-2yl]-2, 5-diphenyltecrazolium bromide) assay was evaluated as a quantitative alternative ro microscopy evaluation of cytotoxic results. A good correlation was obtained for analysis of product extract waters by the rwo methods, with the MIT assay

providing additional certainty for the classification of borderline cytotoxic samples. As a result of the data presented rhe Australian Standard was amended in 2005 (AS/NZS 4020:2005) to include the quantitative MIT assay format. Use of a new positive control, nickel nitrate, was also recommended.

Introduction Evaluation of a product's suitability for use in contact with drinking water has been extensively performed ar the Australian Water Quality Centre (AWQC) in accordance with the Australian and New Zealand Standard AS/NZS 4020 'Testing of products for use in contact with drinking

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water'. A wide range of materials have been tested ro the Standard including pipes, fittings and valves (Glasson, 2002). The Standard specifies test methods to assess parameters rhar have the potential to affect the quality of the water. Products are assessed to determine if they leach substances that may alter taste or appearance of the water, support microbial growth, or release cyroroxic or muragenic compounds or metals. AWQC has

Amendment of the Australian Standard (ASINZS 402 0).

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technical features refereed paper

previously reported on tastes associated with products in contact with water (Marchesan and Morran, 2004). The focus of the current study is on improving the cytotoxiciry resting component.

follows: Samples (2.7ml) were dispensed into sterile 5 ml polycarbonate rubes. Then 300 µL ~ 90 u 80 of !OX Vero growth medium was ,c 70 added followed by I ml of Vero !:? 60 0 cells ( I05- I06cells/mL). Samples 50 were mixed briefly and then plated The cytotoxiciry testing protocol 40 in triplicate (I ml/well) into a 48 ~ 30 following AS/NZS 4020:2002 is ~ 20 well flat bottom tissue culture place carried out as a qualitative :IE 10 Bottom (NUNC) . In each experiment, ultra assessment of cell morphology via 0 pure (Milli-Q) water was used as the microscopy following exposure to -1 0+-...................._I'""""........... _.......- -. . product extracts. Vero (African negative control and 0.4 mlv'.I zinc 10-4 10~ 10-2 10·1 10"' sulfate solution as the positive Green monkey kidney) cells are Metal concentration (mM) exposed to the water extracts for a control. Plates were incubated at 37 Figure 1. Cytotoxicity concentration-response curves ± I °C, 5 ± 0.5% CO2 • Following 24 24 hr incubation period and (MTT assay) for the heavy metals nickel nitrate and ± 2 hr exposure, assessment of cell assessed for morphological changes zinc sulphate. Data were modelled to a sigmoid morphology was carried out via light that indicate a toxic response. A dose-response curve (variable slope). cytotoxic concentration of zinc microscopy, 400 X magnification sulphate is used as the positive (Olympus IX70 inverted microscope) . Samples were control. (dimethyl sulfoxide), trypan blue and categorised as cytotoxic, borderline or nonThis quali tative assessment of cell death via 0.25% porcine trypsin-0 .02% EDTA cytotoxic. microscopy is subjective, relying on • solution were purchased from Sigmaexperience of the technician to achieve Aldrich. Zinc sulfate and nickel nitrate were MTT Assay accurate and consistent results. obtained from BDH Chemicals. The MIT assay was based on the procedure Furthermore, while a si ngle cytotoxic described by Mosmann (I 983). Vero cells Sample Preparation concentration of zinc sulphate is useful in were exposed to product water extracts on demonstrating the appearance of non-viable Water extracts 96 well flat bottom plates (Sarstedt, cells to the technician, without a Extract water was obtained from 67 Australia). Keeping the same ratio of cells to quantitative response it does not allow for produces following AS/NZS 4020:2002 growth area used on the 48-well microscopy monitoring the performance of the assay Appendix F (Section F7.4 - Extraction places, samplc:s were prepared by che over time. Procedure). For each product, 24, 48 and addition of 202.5µ1 of sample, 22.5µL of An alternative quantitative assay was sought 72 hr extract waters were obtained. 10 X Vero growth medium and 75µ1 of to provide a more informative result. The Vero cells (I0 5-I06cells/mL) per well. Six Heavy metals MIT (-(4, 5 dimethylthiazol-2-yl] -2, 5wells were placed per sample. Following 24 Stock solutions ( I0mM) for zinc sulphate diphenylrecrazolium bromide) assay was ± 2hrs incubation at 37 ± 1 5 ± 0.5% and nickel nitrate were prepared in ulcra chosen for evaluation. This assay has been , the MIT assay was carried out. MIT CO 2 pure (Milli-Q) water and adjusted to pH widely used for cytotoxiciry assessment by (5mg/ml) was dissolved in phosphate 7.0 ± 0.05. researchers and industry. Mitochondrial buffered saline (PBS), and then further dehydrogenase activity of viable cells Cell culture diluted in cell culture medium co give a 0.7 convens the MIT salt to a formazan The Vero cell line (African Green Monkey mg/ml solution. The medium was removed product in a colorimetric reaction. The kidney, adherent, epithelial cells) was from microplate wells and 60 µI MIT extent of formazan production relies on the obtained from the American Type Culture solution (0.7 mg/ml) added. Places were amount of viable cells present. Therefore a Collection (ATCC CCL-81) and cultured returned co che incubator (37°C, 5% CO2) decrease in the amount formed indicates the routinely in 75cm 2 flas ks (Sarstedt, for 30 mins. The MIT solution was then degree of cytotoxiciry caused by the test Australia). Cells were maintained in IX removed and 100 µI of dimethyl sulfoxide material. Medium 199 with Earle's salts, added to solubilise the reduced formazan The aim of this srudy was to evaluate use of supplemented with 0.68mM L-glutamine, produce. Plates were placed on a shaker for the MIT assay as a quantitative 0.05 IU/mL gentamycin, 25mM sodium 20 minutes prior to determining the cytocoxiciry assay for testing of products in bicarbonate, 0.0005% (w/v) phenol red and absorbance at 570 nm/reference at 650 nm contact with drinking water. The MIT 7% newborn calf serum (GIBCO). Cells using a Perkin Elmer VICTOR3 (Boston, protocol was established and its quantitative were grown at 37 ± I °C in a humidified 5 ± MA, USA) place reader. A reduction in nature demonstrated by the generation of 0.5% CO2 incubator. Cells were passaged MIT result compared to control cells concentration-response curves to heavy as required using 0.25% trypsin-EDTA (ultrapure water) was expressed as % solution. Cells were used between passage metals used as positive controls. The cyroroxiciry. numbers I - 200, viability 2:90% as correlation between the standard determined by trypan blue exclusion. microscopy method and MIT cytotoxiciry Concentration-response Curves was evaluated using a range of produce Zinc-sulphate and nickel nirrac~ (1 x I Q-4 Cytotoxicity Testing extracts. mM to 0.5 mM) were analysed for Microscopy Endpoint cytotoxiciry by MIT assay as detailed Methods Cytotoxiciry testing using the microscopy above. EC 50 values were determined from Reagents endpoint was carried out as detailed in sigmoid dose-response curves (variable AS/NZ 4020:2002. Briefly, samples co be MIT (3-(4, 5 dimethylthiazol-2-yl]-2, slope). The nickel concentrations were 5-diphenyltetrazolium bromide) , DMSO tested were prepared in growth media as analysed by microscopy and categorised as 110 100

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cytotoxic, borderline or non-cyototoxic. MIT classifications were then defined as follows: cytotoxic MIT >50%, borderline MIT 20-49%; and non-cytotoxic MIT <20%.

Testing of Product Extract Waters by Microscopy and MTT assay The cytotoxicity of extract water (24, 48 & 72hr rime points) from 67 products was assayed by both microscopy and MIT methods as detailed above.

Data Analysis G raph Pad PRISM (GraphPad software, San Diego, California, USA Version 4.00 for Windows) was used for all statistical analyses and graphing.

Results and Discussion Nickel nitrate is recommended as a new positive control The heavy metals zinc sulphate and nickel nitrate (l xlO-4 mM to O.5mM) were used co generate concentration-response curves in the MTT assay. As shown in Figure l, the concentration-response curve for the positive control zinc sulphate is steep, changing from being cytotoxic to non-cytotoxic over a very narrow concentration range. The EC50 (effective concentration required to kill 50% of the cells) was determined as 0.40 mM. If one cytotoxic concentration (O.4O mM) is used as a positive control , it can be seen char a relatively slight operational error in preparatio n of chis concentration could lead to unnecessary rejection of the assay results if a cytotoxic result is not seen . Nickel nitrate, on the other hand, exhibits a broad concentration-response curve over a 3-4 log concentration range. The EC50 was determined as 0.039 mM. Small changes in concentration will not have the same impact on the cytotoxic response. It is therefore recommended that nickel nitrate be used as an alternative positive control. Use of 3-4 concentrations to obtain a range of quantitative MIT results will enable sensitive monitoring of the assay performance over rime.

Nickel nitrate evaluation of MTT response compored to microscopy Nickel nitrate was used to demonstrate {a) non-toxic, (b) borderline and (c) cytotoxic responses as determined by microscopy. These classifications were compared to the MIT result categories.

vessel {Figure 2 {a)). Non-viable cells are rounded, having lost control of cell structure and contact with each other. Nore that there are always some dead cells present, even when the majority of the cells are healthy. This is a potential source of confusion for inexperienced operators relying on visual assessment. The MIT assay result was non-cytotoxic (O o/o cytotoxicity). An example of where uncertainty can arise is illustrated in Figure 2 (b). This sample was classified as borderline cytotoxic by microscopy, showing an increase in the number of non-viable (rounded) cells present compared to the non-cytotoxic result shown in Figure l (a) . Ir was subsequently identified as bei ng noncytotoxic under the MIT classification {l 5% cytotoxicity). It is likely that this confusion by the microscopist was actually caused by too many cells being dispensed into the well. A cyrotoxic result is shown in Figure 2 (c) illustrating destruction of the cell monolayer by the test compound. This was quantified as 76% cytotoxicity by the MIT assay.

Testing of Product Extract Waters by Microscopy and MTT assay To determine whether MIT assay results correspond with microscopy observations, results were correlated for 215 product extract waters rested for cytotoxicity by both methods (Table I). The samples analysed included 3 extracts (24, 48, 72 hr extracts) from 67 products. In addition, some extracts were repeated following dilution. The average intra sample variabili ty of MIT results (coeffi cient of variation on 6 replicates per sample) was 9.17% for this data set. Therefore, the 95% confidence interval on 50% MIT reduction was 45.2- 54.8%. The Pearson correlation coefficient of the two methods was r = 0.54 (p <0.0001). This indicates chat the two methods tend to vary together measuring the same end result. As shown in Table l there were no results classified as cytotoxic by microscopy that were determined to be non-cytotoxic by MIT, and no results classified as noncytotoxic by microscopy chat were determined to be cytotoxic by MIT. Some variability in results from the two methods comes from the 'borderline' classification

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As shown by microscopy, viable cells exhibit an elongated appearance, flattened out to form a monolayer on the culture Journal of the Australian Water Association

water

AUGUST 2007 57


technical features refereed paper

group. In chis group, 12 out of 19 samples classified as borderline by microscopy were determined co be non-cytotoxic by MIT assay. The classification of a borderline result by che microscopist occurs when the operator is unsure whether cycocoxicity has occurred or not based on the morphology of che Vero cells. The protocol then requires the produce extract water co be retested co confirm the resulcs. As illustrated here, chis additional work in confirming a borderline sample could be avoided by use of the MIT assay co provide a quantitative answer.

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Conclusions

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The MIT assay was demonstrated co be a suitable quancitacive cycocoxicity assay for testing of products in contact with drinking water, with good correlation co m icroscopy for determining cytotoxic and noncycocoxic resulcs. The quantitative MIT assay had a distinct advantage over microscopy when borderline cytotoxic samples were reseed, eliminating uncertainty in results and avoiding che need co re-cesc che samples. As more produces are reseed, che MIT classifi cations will be further refined.

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Furthermore, nickel nitrate was identified as a suitable positive control for cycocoxicity testing. Use of chis heavy metal at 3-4 concentrations in the MIT assay would allow sensitive monitoring of the assay performance over time by the use of standard quality control procedures such as Sheward charts.

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As a result of the data presented, the Australian Standard was amended in 2005 (AS/NZS 4020:2005) ro incl ude the q uancicacive MIT assay format. U se of a new positive control, nickel nitrate, was also recommended.

Figure 2. (a) Non-cytotoxic, (b) borderline and (c) cytotoxic responses obtained following 24 hr exposure of Vero cells to varying concentrations of nickel nitrate. MTT assay results are compared to microscopy observations.

Acknowledgments The Authors

This work was funded by an SA Water Research and D evelopment grant. Michael G lasson (Team Leader, Produce T esting) and Warwick Grooby (Manager, Microbiology Services) both of AWQC are thanked for valuable advice and support.

Stella Fanok is a T echnical Officer, Suzanne Froscio is a Research Officer and Andrew Humpoge (andrew.humpage@ sawacer.com.au) is a Senior Research Scientist at the Australian Water Quality

Table 1 Correlation between microscopic classification and MTT result for 215 water extracts.

MTT Result

Cytotoxic

Cytotoxic Borderline Non<ylotoxic

58 AUGUST 2007

>50% 20.49% <20%

water

Microscopic Classification Borderline Non-cytotoxic

5 2

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Centre, Private Mail Bag 3, Salisbury, Sou ch Australia, 5108, Australia.

References Glasson, M. (2002). AS/NZS 4020 ' Produces fo r use in contact with drinking water'. APR/ journal December, 27. Marchesan, M., and Morran, J. (2004). Tastes associated with produces in contact with drinking water. Water Sci Ttchnol 49, 227-231. Mosmann, T. (1983) Rapid colorimetric assay for cellular growth and survival: application to proliferation and cycocoxiciry assays. J Immunological Mtthods. 65, 55-56. Standards Australia. Australian/New Zealand Standard AS/NZS4020:2005. Testing of

products for uu in contact with drinking water.


technical features refereed paper

THE ENHANCED GREENHOUSE EFFECT: THREATS TO AUSTRALIA'S WATER RESOURCES . PART 2: POTENTIAL IMPACTS AND SOLUTIONS AB Pittock Summary Climate change may have more severe impacts than earlier projected on rural and urban water supply in Australia, both directly via changes in rainfall and increases in evaporation, and indirectly via changes in wildfires, land cover, soil erosion, siltation, water quality and sea-level rise impacts on salinisation of coastal aquifers and estuaries. Solutions must include both adaptation and reductions in greenhouse gas emissions both locally and globally. Some hopeful ideas are explored.

Introduction Pare 1 of chis paper established chat climate change is happening, and that it presents a prospect of decreasing rainfall in southern parts of Australia, possible increases in the primarily north-western summer monsoon regions, and a possible trend towards more frequent and severe El Nifio type "droughts" centred on New South Wales, northern Victoria and southern Queensland. The observations suggest these changes are already having effects on water supply. Here I will outline some possible ramifications in the water supply sector and outline my view as to what might be done about it.

Potential Impacts In addition to the impacts of climate change on rainfall, water supply is likely to continue to be negatively affected by global warming via regional increases in evaporative losses (Nicholls, 2004),

Figure 1. Photo of Lake Wendouree, Ballarat, Victoria, in January 2007. Lake Wendouree was the venue for the Olympic rowing in 1956. Boatsheds are visible at far side. Photo by A B. Pittock. This is perhaps typical of what may become common place in many parts of southern and eastern Australia as climate change continues. aggravated by increased demand (Power et al., 2005). A combined tendency to decreases in water supply is likely co be especially severe in southern Australia and, with somewhat less certainty, in eastern Australia. Continued increases in the summer monsoon may well increase runoff in northern Australia, bur here storage is a big problem, with little built capacity, high evaporative losses and large distances to most existing centres of water demand.

A bleak scenario for southern and eastern Australia.

It cannot be stressed enough chat runoff, as the generally small difference between the much larger quantities of precipitation and evaporation, is more sensitive to climate change than precipitation alone. Where precipitation decreases and evaporative losses increase, as now seems likely in southern and eastern Australia, this can lead to large reductions in available water supplies. Thus in the now classic case of the Perth water supply, the observed multidecadal decrease in average rainfall after 1976 was only some 10 to 20%, but inflow into Perth's water supply decreased by some 40 to 60% (IOCI, 2002) . Even greater

.....

M1a1. . . GHIM-

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reductions have been experienced in recent years in the flow of the Murray-Darling river system, where evaporative and seepage losses are large. Episodic penetration of monsoonal activity further south is likely in summer, but chis will likely occur in heavy rainfall outbursts causing local or regional flood ing, with little likelihood of lasting benefits to water storage levels in the southern MurrayDarling Basin nor in urban storages in southern Australia. In general, occasional heavy rain in summer, when the soil is dry and potential evaporation is large, is less effective in terms of runoff than equivalent Fainfall in winter when soils are recharged and potential evaporation is less. Major cities such as Perth, Adelaide, Melbourne, Canberra and Sydney are thus very likely co continue to suffer major water shortages, with shortages also quite likely in Brisbane and Hobart. Many smaller rural cities and towns will also be under dire threat of continued and exacerbated water shortages. The situation dramatically illustrated in Figure l is likely to be common place. Continued "drought" conditions (compared to a mid-20th century baseline), will also lead, along with higher temperatures and episodes of low humidity, to an increased frequency and intensity of wild fire (Williams et al., 200 l; Cary, 2002, Hennessy et al., 2006). This is likely to lead in the short term to reduced land cover and shifts in ecosystems, especially if the intervals between fires become shorter than the time needed for forests to regrow. Reduced land cover in turn will lead to more rapid runoff and more severe water and wind erosion, leading to increased siltation of rivers and water storages (Warner, 1995; Prosser et al., 2001; Scott, 2001; Pitcock, 2003). However, regrowth after a few years leads to a decrease in runoff due to increased evapotranspiration in rapidly growing vegetation. This can lead to long-term decreases in runoff of as large as 50%, lasting decades co a century depending on species and fire recurrence intervals (Kuczera, 1987; Marcar et al., 2006) . Water quality will be adversely affected by runoff of ash and nutrients after forest fires (as experienced in Victoria in 2007). H igher temperatures will add to chis problem by fostering eutrophication and algal blooms in riverine and estuarine systems (Pitcock, 2003; UN, 2003). Both flash floods in small catchments and wider flooding in large catchments are likely to increase in frequency and severity due to the increasing strength and southward 60 AUGUST 2007

water

penetration of the summer monsoon and related tropical lows and monsoon troughs. Tropical cyclones are also likely to become more intense (IPCC, 2007), and as they cross the coast turn into tropical lows that often travel further south (Pitcock et al., 2006).

Australians, but both are capital intensive and will lead ro higher prices for energy (and thus treated or desalinated water). Moreover, both are decades from coming online in significant quantities (Cook, 2006; MacGill et al., 2006; Falk et al., 2006).

In coastal and estuarine areas rising sea levels will add to these problems by causing saltwater intrusion into coastal aquifers and estuaries, especially where barrier dunes are breached allowing sea water into coastal wetlands (Ghassemi et al., 1996). Salt water intrusion is likely to be aggravated by an increased reliance on bore water in coastal areas.

This leaves renewable energy, which many leading Australians have repeatedly seated cannot supply base-load power (but see: Diesendorf, 2006, 2007; TREC, 2007). There are two things wrong with this negative argument regarding renewable energy, especially for water supply:

What to Do? Water supply challenges are already with us. We therefore have to adapt to them. But perhaps more importantly, things will get worse unless we turn around the global warming process that is brought about by the increasing emissions of greenhouse gases from human activities. Both adaptation and emissions reductions are urgent challenges, and ideally we need solutions chat will contribute to both. Adaptation is a local problem. Reducing greenhouse gas emissions is both a local and global problem. Higher average temperatures provide an argument against increased water storages, especially in shallow valleys, which are the only remaining options in many developed regions. Moreover, increased storage capacity is of little use if we cannot fill existing storages. More efficient water use, and the avoidance of evaporative losses through greater use of pipes rather than open channels are obvious partial solutions, but the competition between rural and urban water supply is a growing concern and long-distance transfer of water requires large amounts of energy for pumping, and is therefore costly and likely to add to greenhouse gas emissions unless powered by renewable energy sources. This leads to the possibility of effectively increasing water supply through the treatment and reuse of water, or the desalinisation of brackish groundwater, water in estuaries, and sea water. Both reuse and desalinisation require energy, which is costly and potentially would contribute more to greenhouse gas emissions if the energy comes from fossil fuels. Australia is of course well endowed with large potential supplies of coal, uranium and renewable energy, especially solar, tidal and wind energy. So-called "clean coal" and nuclear energy seem to be the present favoured options by at least some influential

Journal of the Australian Water Association

â&#x20AC;˘ Firstly, to treat or desalinate water does not require base-load energy, but can utilise peak energy supplies when they are not needed for ocher purposes, e.g. in peak summer sunshine, at peak tidal flows, or in wi ndy conditions, provided the capital investment in the desalination plant is not prohibitive. â&#x20AC;˘ Secondly, renewable energy can be stored and made available as required for either base-load or peak demand. Besides the direct use of batteries, which are expensive as energy storage devices, energy from renewable sources can be, and is, stored efficiently by a number of techniques including the latent heat of melting of large volumes of sale, heat storage in large thermal mass such as rock piles, generation of bulk electrolytes that can later be run through batteries, or even the generation of hydrogen for use as a fuel on demand. One particularly inspiring example is a proposal by the Trans-Mediterranean Renewable Energy Cooperation (TREC, 2007) for a network of renewable energy generators across Europe, the Middle East and North Africa. This would be linked by direct current high voltage cables, such as that presently in use across Bass Strait, which are highly energy efficient. The main source of energy would be solar thermal stations in North Africa and the Middle East, which concentrate solar energy to raise steam which powers electrical turbines. Excess heat is scored in tanks of molten salt for use at night or at times of low sunlight, while waste heat or excess electricity can be used to desalinate seawater. TREC estimates chat they can supply all of Europe's electricity needs by 2050 ar a cost (including transmission) of about 5 Eurocents per Kilowatt hour, which is competitive with alternative power sources, especially if a price is placed on carbon dioxide emissions. Solar-thermal systems are in operation in several European countries and in the US in California and Nevada, and in experimental setups in Australia (Lovegrove and Dennis, 2006).


technical features refereed paper

Development of such a scheme on a small bur increasing scale in Australia is one hopeful possibility.

Conclusions Boch adaptation and reductions in greenhouse gas emissions, locally and globally, are needed urgently. Adaptation measures are essentially local or regional, but should not aggravate rhe global climate change problem, which would be counterproductive. The best solutions include increasing water use efficiency, recycling and desalinisation powered by renewable energy supplies, plus urgent participation in global efforts to reduce emissions. Such solutions do seem possible, but much effort is required in all these areas in the next decade if we are ro have secure urban and rural water supplies.

Acknowledgments T hanks are due to the Chief of CSIRO Marine and Atmospheric Science for continuing my Honorary Fellowship, and to Tim Cowan of CSIRO for help with Figures. I also wish to thank Wenju Cai and Ian Smith of CSIRO for their critical comments which have been most helpful.

The Author

Dr Barrie Pittock is an Honorary Fellow CSIRO Marine and Atmospheric Research. He retired in 1999 as Leader of the CSIRO Climate Impacts Group, and was awarded a Public Service Medal. H e is the author of

Climate Change: Turning Up the Heat (CSIRO Publishing, 2005), email: bpittock@bigpond.com; barrie.pittock@csiro.au

References Cary, G.J. (2002), Importance of changing climate for fire regimes in Australia. In: Bradstock, RA, J.E. Williams and M.A. Gill (eds.), Flammabk

Awtralia: The Fire Regimes and Biodiversity ofa

Continent, Cambridge University Press, UK, pp. 26-46. Cook, P.J. (2006), Carbon dioxide capture and storage: research, development and application in Australia. lnternat. J. Environmental Studies, 63, 731-750. Diesendorf, M. (2006), Wind power in Australia. lnternat. J. Environmental Studies, 63, 765776. Diesendorf, M. (2007), Gmnhowe Solutiom with Sustainabk Energy, University of New South Wales Press, Sydney. Falk, J., J. Green and G. Mudd (2006), Australia, uranium and nuclear power. lntemat. J. Environmental Studies, 63, 845-858. Ghassemi, F., K.W.F. Howard and A.J. Jakeman (1996), Seawater intrusion in coastal aquifers and its numerical modelling. In: Environmental Modelling, Zanneti, P. (ed.), Computational Mechanics Publications, Southampton, UK, Vol.3, pp.299-328. Hennessy, K., C. Lucas, N. Nicholls, ) . Bathols, R. Suppiah and J. Rickens (2006), Climate change impacts on fire-weather in south-east Australia. Consultancy report for the NSW Greenhouse Office, Vic. Depc. Sustainability and Environment, Tas. Dept. of Primary Industries, Water and Environment, and the Australian Greenhouse Office. CSIRO and Bureau of Meteorology, 78 pp. IPCC (2007), Climate Change 2007: The

Physical Basis, Summary far Policymakers. lntergovernmental Panel on Climate Change, Geneva (see: http://www.ipcc.ch) IOCI (2002) . Climate Variability and Change in South West Western Australia. Indian O cean Climate Initiative, Perth, 36 pp. See: http://www.wrc.wa.gov.au/ioci/news.hcm. Kuczera, GA (1987) Prediction of water yield reductions following a bushfire in ash-mixed species eucalypt forest. journal of Hydrology, 94, 215-236 Lovegrove, K, and M. Dennis (2006), Solar thermal energy systems in Australia. lnternat. J. Environmental Studies, 63, 791-802. MacGill, I., R. Passey, and T. Daly (2006), The limited role for carbon capture and storage (CCS) technologies in a sustainable Australian energy future. lnternat. J. Environmental Studies, 63, 751 -764.

Marcar, N.E., R.G. Benyon, P.J. Polglase, K.1. Paul, S. Theiveyanathan and L. Zhang (2006), Predicting the hydrological impacts of

bwhfim and climate change in forested catchments ofthe River Murray Uplands: A Review. CSIRO: Water for a Healthy Country National Research Flagship. Nicholls, N. (2004), The changing nature of Australian droughts, Climatic Change, 63, 323-336. Pitcock, A.B. (2003). Clil/lilte Change: An

Australian Guide to the Science and Potential Impacts, Barrie Pirtock (ed.). Australian Greenhouse Office, Canberra. See: http://greenhouse.gov.au/science/pubs/science -guide.pdf. Pittock, A.B., D. Abbs, R. Suppiah and R. Jones (2006). Climatic background to past and future floods in Australia. In: Floods in an Arid Climate, Poliani, A. (ed.), Advances in Ecological Research 39, 13-39, Elsevier/ Academic Press. Power, S.B., 8. Sadler, and N. Nicholls, 2005: The influence of climate science on water management in WA: lessons for climate scientists. Bulletin American. Met. Soc., 86, 839-844. Prosser, J.P., l.D. Rutherford, J .M. Olley, W.J. Young, P.J. Wallbrink and C.J. Moran, 2001: Large-scale patterns of erosion and sediment transport in river networks, with examples from Australia. Marine and Freshwater Research, 52, 81-99. Scott, A. (2001), Water erosion in the MurrayDarling Basin: Learning from the past. CSIRO Land and Water, Tech. Report 43/01, November 2001, 134 pp. TREC (2007), Clean power from the deserts. Available at http://www.TREC-EUMENA. net. UN (2003), United Natiom World Water Development Report, World Water Assessment Program. See: http://www.unesco.org/water/ wwap/wwdr/index.shcml. Warner, R.F. (1995), Predicting and managing channel change in Southeast Australia. Catena, 25, 403-418. Williams, A.J., D.J. Karoly and N. Tapper (2001), The sensitivity of Australian fire danger to climate change. Climatic Change, 49, 171 -1 91.

H~N~

instruments

tel: +61 39769 0666 fax: +61 39769 0699

email: hannains@ hannainst.com.au

www.hannainst.com.au Journal of the Australian Water Association

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AUGUST 2007 61


tech ·r~I

t:l

tures

desalination

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TREATMENT OF WASTEWATERS BY RO: OPERATING ISSUES - PART 1 A Davey, R Schumann, K Hoehn Abstract There are significant issues in operating an RO desalination plant to reclaim water from treated effiuents. While fouling due to mineral scaling is well understood and can be controlled by anti-sealants, other rypes ~f foulants due to both industrial contaminants and domestic contributions are less understood or well controlled within wastewater reclamation plants. This two-part paper outlines a strategy for the treatment of wastewater usi ng RO membrane technology. In Part I of this article we provide a general approach to testing and measuring parameters relevant to the performance of RO membranes and in Pare 2 provide options for selecting pretreatment options to prolong the life of the membranes.

Membrane treahnent for the Eastern Irrigation Scheme located close·to Melbourne.

Introduction Membrane technology is now being widely adopted for both water production and reclamation. The combined pressures of climate change and water conservation are encouraging wastewater reuse and improvements in membrane filtration to protect community health. Recycled water in Australia is now used for irrigation and industry with indirect potable reuse now becoming more likely.

the membrane does not necessarily have a high rejection of synthetic and pharmaceutical compounds commonly found in wastewater; this is especially true of uncharged small molecular weight organic molecules which can pass into the permeate. fl I

Membrane technology is capable of efficient removal of contaminants from wastewater. Reverse Osmosis (RO) has been shown to accomplish the best overall removal of organics, metals and Total Dissolved Solids (TDS), and the potential to remove all classes of micro-organisms. RO in combination with adequate pretreatment can provide the desired water quality in terms of salt and nutrients.

I n the case of indirect potable reuse, some micro-pollutants which are commonly found in wastewater are potentially harmful when present in drinking water. Endocrine disruptors, which are derived from the use of pharmaceuticals in humans and livestock, are among the micro-pollutants in this category12l. Trace organics such as biocides, endocrine disruptors (e.g. ibuprofen), carcinogens (e.g. disinfection bi-products), surfactants and chelating agents (e.g. EDTA, NTA, etc) still present a major challenge to membrane treatment.

While RO has the smallest pore size compared to other membrane technologies,

There are significant issues related to operat ing a RO desalination plant to

+GF+ Piping & Flow Control Speclellsta

reclaim water from effiuent sources. While fouling due to mineral scaling is well understood and can be controlled with anti-sealants, other types of foulants due to industrial contaminants are less understood or well controlled within wastewater reclamation plants. Organic chemicals are likely to be derived from a number of point sources which may end up in the treated effiuent and potentially foul the RO membranes. In fact, contamination of the environment can occur from simple routes such as manufactured products or industrial sources, pharmaceuticals, pesticides, agricultural runoff, accidental spills and releases of compounds, chemicals used in PVC manufacture, plasticisers, detergent products and personal care productsl31.

Identifying potential membrane foulants.

GEORG FISCHER

PIPING SYSTEMS

f.e\ec Ph: 07 3390 7166 Fax: 07 3390 7177 Email: info@allflowsupply.com.au Web: www.allflowsupply.com.au

62 AUGUST 2007

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Journal of the Australian Water Association

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


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MEMBRANE SYSTEMS


technical features

The p rimary goal fo r m ost m u nicipal W aste Water T reatment Plants (WWTPs) is the protection of receiving waters from pollution (or nutrients) and n ot the removal of industrial contaminants or refractory organics that cause issues with memb rane rreacmenrl 41. It is therefore necessary to cry to identify the co ntaminants in the efflu ent to p rovide som e warning about p otential fo uling issues to be faced by reverse osmosis.

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Characterisation of Tertiary Treated Wastew a ter T here are several groups of residual organ ic chemicals such as Synthetic Organ ic C o m po unds (SOC), Natural O rganic M atrer (NOM) and Soluble M icrobial P rod uces (SMP) generated d uring wastewater creatmentl5l. T he un iden tifi ed bulk of residual coral o rganic carbon (TOC) is also designated as Efflue nt Organic m atter (EfO M ). T o properly characterise rhe fo uling potential of EfOM it must be characte rised accordi ng to size, structure and fu nctio nali ty and for practical purposes by operating an RO pilot uni t for 3 months on the particular feed water source. Its potential fo r interaction with the mem b rane can be determined by mo lecular weigh t d istributio n , fract ionation and fun crional group analysis. C ertain contam inants contai ned in EfOM which are not removed in the pre-trearment step m ay adsorb onto the RO membranes w ith drastic results such as loss o f planr p roducrion, excessive chemical cleaning, and reduced m embrane life. T here are usually higher levels of chemical oxygen demand (COD) and nonbiodegradable matter in wasrewarers in compariso n with o cher water types, due to the p resence of EfOM and indusrrial micropollurants. To red uce t he effects of fo ulin g it is necessary to rem ove degrading o rganic m atter and ascertain a rrue indication o f refractionary organics no r rem oved in rhe preced ing WWTP. H ence a typ ical approach to fully characterising the wasrewarer sho uld inclu de: • Silt Densiry Index (SDI) resring and d etermi nat ion of colloidal fractions; • High Perfor m an ce Size Exclusio n C hrom atography (H PSEC) to determine th e m olecular weight d istri bu tion of o rganics (5 0 to 50,000 Dalrons); • Rap id Resin Fractionatio n to determine the o rganic character fraction co ncen trat ion , including humic and fulv ic acid co ntent and hydrophobi c and hydro philic fractions;

64

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~ - - - - - - - - -" - - - - - - - - - - - - - - - - - - - - - ~m"'-'~\!~-~ Figure 1. GC-MS chromatograms of DCM extract of effluent adjusted to pH l l (top) and pH 2 a fter addi tion of diazomethane (bottom). Peaks marked w ith X indicate substa nce fou nd in a blank a na lysis.

• G as C h ro matography/Mass Spectrometry (GC/MS) to id entify specifi c organic m olecules either through membrane ext raction or grab samples of wastewater. Check for sp eci fic co m pou nd s known to typically fou l and interfe re with RO membrane performan ce, e.g. hydrocarbons, phenols, kerones, aldehyd es, non-ion ic and catio nic surfactants, quaternary am m onium compounds, iodine, and stro ng oxidising agents to nam e a few; • TOC and D issolved O rganic Carbo n (D OC); • T he assimilable o rgan ic carbon (AO C) to provide a measure o f the bacterial grow th potential of treated warer; • An alysis of inorgan ic consti tuents through ro ut ine laborato ry resti ng; • Inclusion of pilot p lan t testing and a membrane au topsy at the en d of the testing period . Attenuated Total Reflectance Fourier T ransfo rm In frared Spectroscopy (ATR-FTlR) can be used to identify So luble M icrobial products (SM P) and Extra-cellular polymeric substances (EPS) that maybe causing foul ing of the RO m embrane. Furtherm ore, membrane comparib ilicy can be compared w ith

Journal of the Australian Water Association

questionab le key com pounds kn own to be present constantly or sporad ically in the p re-treated RO feedwaterl6J. The SDI is a simple and q u ick resr to determ ine the amount of coll o idal mater ial grearer rhan 0.45 um . Boch microfi lrracion (M F) and ulcrafil cracion (UF) can provide a SDI less than l, with pre- treatmen t by UF providing a 30% decrease in pressure to operate the RO system in compariso n to an RO system on lyl7l. It s hould also be noted that a Membrane Fouling Index (MFI) is now being developed co provide addi tional perfo rmance info rm ation for RO op erarion . For example, EfO M after u lrrafil crario n generally contains a sizeable portion of colloidal organi cs of molecular weigh t less than l 000 Dal ton s. This fra ction of colloid s/solu tes is not meas ured by the SD I test. H ence, there is a large fraction of colloidal m atter chat could poss ibly cause o rganic or increase b io-fouling o n the RO mem brane if not p roperly characterised and d ealr with app ropriately. Arrenuaced T otal Reflectan ce Fourier T ransform In fra red Spectroscopy (ATRFTIR) can also identify fu n ctio nal groups of organic materials de positing o n the membrane surface. FT IR can analyse


technical features

functio nal group peaks at wave numbers of 1540 to 1640 cm- 1 char represent primary or secondary amides often associated with proteins, peaks at 1040 cm- 1 representing polysaccharides, proteins and possibly bacterial cell walls, and peaks at 1720 cm- 1 indicative of carboxylic groups typical of humic and fu lvic acidsl81. Soluble proteins can make-up approximately 90% of the EfOM with molecular weights> 10 kDa. GCMS can be used to characterise low molecular weight organic constituents present in wastewater. The RO membrane supplier can often provide advice on particular organic and inorganic compounds char are detrimental to membrane performance (i.e. hydrocarbons, solvents or heavy metals) usually present in the wastewater as a result of industrial discharges. Comparison of the compounds identified by GCMS in rhe wastewater which is to be created by the RO membrane and chose compounds identified by the memb rane manufacturer as potentially derrimenral, will help in determining which, if any, sol uble species present in rhe wastewater could be problematic to good membrane performance. For example, a recent GCMS chromatogram obtained from dichloromerhane extracts of effl uent created in a membrane bioreactor identified two major orga nic fractions in the tertiary created effl uent (as shown in Figures I and 2). The base-neutral fract ion (pH 11 extract) indicated che presence of cripropylene glycol, and a number of burylaced phenols. T he presence of bucylaced phenols in che wastewater is not unexpected as they are frequenrly used in commercial produces as antioxidants. T he acid fract ion (pH 2 extract) included a number of saturated fatty acids or hydrolysis produces of lipids commonly foun d in wastewater. In addition, two aromatic acids were also identified. Particular SOC identified by GCMS analysis, which can also be detrimental co membrane performance included: • various metabolites of bucylaced phenols;

bio-reaccors maybe an acceptable form of pre-treatment for wastewater desalination (and it depends on the source of wastewater) there still appears co be a significant portion of compounds char are passing direcrly through the filter onto the reverse osmosis membrane.

Selection of the RO Membrane T he most commercially available membrane configuration is rhe spiral wound polyamide based chin film composite reverse osmosis element. The membrane aces as a molecular filter char rypically removes 95 ro >99% of dissolved inorganic ions. The spiral wound membrane has a chin dense surface on one side which aces as a semi-permeable barrier while che other aces as a support layer. Reverse osmosis works through che application of an external pressure greater than osmotic pressure co cause water co flow through a semi-permeable membrane from the high sali nity side co the low saliniry side of the membrane. There are a large number of choices for selecting an RO element for wastewater

creacmenr. These include evaluating membrane types, membrane surface charge, fouling resistance, feed channel spacer thickness, active membrane area in the element and element construction, feed pressure requirements and rejection levels of dissolved ions and organics. Low Fouling or Fouling Resistant Membranes offer significant advantages in long term flux stability when compared co conventional Thin Film Composite (TFC) membranes. Pilot plane resting of reverse osmosis membranes is the only way co find the optimum choice. Typically, acceptable wastewater limits for desalination are 3 ppm ofTOC (Toca! Organic Carbon as C), 6 ppm of BOD (Biological Oxygen Demand as 02) or~ 10 ppm of COD (Chemical Oxygen Demand as 02). The actual co ncentrations chat are still acceprable for sustainable operation of the RO membranes can vary significanrly depending on the nature of che consriruenrs char actually make up the TOC, COD and BOD. To maxi mise the efficiency and life of a RO system, effective pre-treatment of the RO

View a demonstration of ROCI at Stand 17, Victorian Wat.er Industry Engineers & Operators Bendigo Exhibition Centre, September 4-6th

• 2,4-dimechyl benzoic acids fou nd in pharmaceutical produces; • rri-propylene glycol which is commonly used in paints and industrial coatings; and • benzyl alcohol used in the production of plastics. Many of rhe industrial compounds identified are hydrophobic in nature which may adsorb and form a waxy coating on the RO membrane surface. Such coatings are hard to remove through chemical cleaning. In chis particular case, while membrane

Email: sage@sagetechnologycom.au

www.sagetechnology.com.au

SAGE TECHNOLOGY Journal of the Australian Water Association

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AUGUST 2007 65


technical features

feedwate r along with selection of appropriate operating flux is required to minimise fou ling, scaling and degradation of membranes over their operating lifetime. The rate of membrane surface fou ling is a funct ion of permeate fl ux rate, measured as L/m2/ h (litres per square metre of membrane area per hour). The lower the flux rate, the lower the rate of fouli ng and at h igher flux rates the rate of fou ling will increase steadily up to a critical flux rate above which fouling will increase exponentially. The relationship o f foul ing rate to the flux can usually be demonstrated both during pilot testing and full scale plant operation . The increase in fou ling race with higher flux is a resulc of higher concentrations of organics and ocher fou lants at the membrane surface and higher drag force perpendicular to membrane surface. A higher cross flow velociry (feed-brine flow) parallel to the membrane surface usually helps to lower rhe rate of fouli ng. Foulants are flushed away from the membrane surface by the higher shearing action . Higher area membrane elements allow for the use of fewer pressure vessels and higher feed and concentrate flows. H ence, foul ing is known to increase as cross flow decreases, flux increases and concentration of the foulant increases. C ritical flux is also an important parameter because this is the point at which deposition of particulates, micro-organ isms and precipitation of species of limited solubiliry commences for a given feed and cross-fl ow velociryl91.

Summary There are significant issues related to operati ng a RO desalination plant to reclaim water from effluent sources. W h ile fou ling due to mineral scali ng is well understood and can be controlled with antiscalants, other rypes of foulants rypically found in created effluents are less understood or well controlled within wastewater reclamation plants. The identification of these contaminants in the wastewater and use of proper analytical techni ques to characterise them are relevant to the performance of the RO membrane for desalination. The choice of the membrane rype, active membrane area etc., is also important in optimising desalination performance. Finally determining the optimum permeate flux race to minimise fou ling while still maintaining acceptable product water generation rates is critical to the successful desalination of treated effluent with RO membranes W ith d ifficu lt wastewater it is necessary to review the risks of operating che reverse osmosis after pre-treatment. Some organic

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Retention Time (min) 13.59 13.83 13.91 15.05 15.50 16.86 17.05 17.51 17.72 17.99 19.20 20.11 20.56 20.61 21.21 22.05 22.29 23.26 23.78 23.94 24.26 26.02

Identification Nonanoic acid Trioroovlene alvcol isomer Trioroovlene alvcol isomer Decanoic acid Dimethyl benzoic acid o-Ethoxvbenzoic acid 2,6-di-t-butvl-2,5-cvclohexadiene-1,4-dione 2,6-di-t-butvl-phenol Dodecanoic acid Nonanedioic acid Benzoohenone Tetradecanoic acid 3,5-di-t-butyl-4-hydroxybenzyl alcohol 3,5~i-t-butvl - 4-hydroxybenzaldeyde Pentadecanoic acid 2,6-di-t-butvl-4-nitro-phenol Hexadecanoic acid2 (Palmitic acid) Heotadecanoic acid Manool Linoleic acid Octadecanoic acid (Stearic acid) Eicosanoic acid

Figure 2. Compounds identified by GC-MS analysis of the DCM extracts of the effluent sample at pH 2 and 11 .

and industrial compounds are not removed effectively by the biological wastewater t reatment, tertiary filcration or chemical addition. Careful design of pre-treatment is necessary to minimise RO foul ing from colloidal, organic and biological foulants. In part 2 of this article we will d iscuss options for adequate pre-treatment.

The Authors Anthony Davey is the Technical Manager IMD, Earth Tech, Melbourne Australia (anchony.davey@earthtech.com.au); Russell Schumann is a Senior Research Fellow with Levay & Co Environmental Services in the Ian Wark Research Institute at the Universiry of South Australia (Russell.Schumann@un isa.edu.au); and Kai¡Uwe Hoehn is a Senior Account Manager for Dow Water Solutions - Dow C hemical (Australia) Limited, based in Sydney (kuhoehn@dow.com). References [l ) DOW Technical Fact Sheet "Estimated Percent Rejection of Various Solutes by FILMTEC Membranes" - Form No. 60900240-204 [2) Falconer I.R., Chapman H.F., Moore M., Ranmuchugala G., "Endocrine-Disrupting Compounds: A Review of Their Challenge Sustainable and Safe Water Supply and Water Reuse" (2006)

Journal of the Australian Water Association

to

[3) Petrovic M ., Gonzalez S., Barcelo D., "Analysis and removal of emerging contaminants in wastewater and drinking water", Trends in Analytical Chemistry, Vol.22, No.10 (2003), pg 685 - 696 [4) Davey A, Schumann R. and D avey, D., "Characterising Wastewater for Ulrrafilrrarion", Water, Vol 33 No 4, (2006). pg57-61 [5) Jarusutthiraka C., Amy G. and Crouec J.P. " Fouling characteristics of wastewater effiuent organic matter (EfOM) isolares on NF and UF membranes", Desalination 145 (2002) pg 247-255 [6] Chapter 9.1 1 "Testing Chemical Comparibiliries wirh FILMTEC Membranes - Dow Liquid Separations FILMTEC Reverse Osmosis Membranes Technical Manual", July 2005 Form No. 609-0007 10705 [7] Leslie, G.L, D univin W.R. Gabiller P., Conklin S.R., M ills W.R, Sudak R.G "Pilot resting of micro filtration and ulrrafiltration upstream of reverse osmosis during reclamation of municipal wastewater" Proc. Amer. Desalination Ass. Nae. Conf, Monterey, CA, Aug 4. (1996) [8) Jarusutthiraka, Amy G . "Membrane filtration of wastewater effiuenrs for reuse: effiuenr organ ic matter rejection and fouling", Water Sci. Tech. 43 (200 1), pg 225 - 232 [9] Fane A.G., Li H., Beatson P., ea! P.R. "Critical Flux Phenomena and its implications for fouling in Spiral Wound Membranes", International Desalination Association (1999)


technical features

desalination

TOLERANCE OF MARINE LIFE TO DESALINATION PLANT DISCHARGES N Voutchkov Abstract This work presents a novel method for establish ing the site-specific maximum level of salin ity concentrat ion (salin ity tolerance threshold) at which marine organ isms not only survive, bu r can also grow and reproduce normally. The described method was used successfully fo r permitting the ocean discharges of two large seawater desalination projects in California, USA the 20 0 ML/d (50 MGD) Carlsbad and Huntington Beach desalinat ion plants.

Introduction Seawater desalination planes produce concentrate (brine) which is usually 1.5 to 2 rimes h igher than the concentration of total dissolved solids (T DS or salinity) of the ambient seawater (normally in the range 30-40 parts per thousand (pp r). W hen returnc::<l tu rhe ocean without dilurion, the concentrate may have negative impact on the aquatic environment in the area of the d ischarge. This impact is very sire-specific and d epends to a great extent on the salinity tolerance of the specific marine organisms in habiting the water column and benchic environ ment influenced by the discharge. T he existing US EPA whole effiuent toxicity (WTE) tescs are indicative of the level of salinity which causes mortality of pre-selected test organisms, which may or may not in habit the d ischarge area. T his work presents a novel method that enables establish ing the site-specifi c maximum level of salinity concentration (salinity tolerance threshold) at which marine organisms not only survive, bu t can also grow and reproduce normally.

Salinity Tolerance Threshold of Marine Species Environmentally safe disposal of the concentrate produced at seawater desalination planes is one of the key factors determin ing the viability, size and costs of a given project. The maximum total dissolved solids (TD S) co ncentration that can be tolerated by the marine organisms living in the desalination plane ou tfal l area is defined as a salinity tolerance threshold and depends on the type of the aquatic organisms inhabiting the area of the discharge and the period of rime these

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Figure 1. Collocation of Carlsbad Desalination Plant with Encino Power Station.

organisms are exposed to the elevated salinity. H ow well organ isms adapt to salinity d epends to a great extent on the aquatic environment in which these organisms have evolved. Strictly marine species such as the sea urchin, the sand dollar or the sea star (starfis h) encounter little variation in salinity in their natural environment and have more limited ability to control the salinity of their body flui ds. These organisms however, are typically more sensitive to low sal in ity (fresh water discharges such as effluents from wastewater treatment planes), rather than h igh salinity exposure. The maxi mum salinity these species could withstand is often in a range of 50 to 75 ppr. Most fis h can survive maximum TDS levels of 75 to 85 ppr, while benth ic worms have been found in Laguna Madre, Texas (in the USA), living in salinity range of 50 to 80 pp r. Salinity tolerance of most marine species also depends on the stage of their d evelopment - usually adult species are more salinity tolerant than the embryos. For example, many ad ult barnacles can survive salinity of up to 100 ppr wh ile at

Establishing the site-specific tolerable level ofsalinity.

embryonic stage of development they cannot typically tolerate concentrations higher than 65 p pr.

Novel Method for Salinity Tolerance Assessment Since the marine organisms and environmental conditions are usually sitespecific for the area of each desalination ou tfall, a general rule of thumb for determining the salinity tole rance of the entire marine habitat in the ou tfall area is very diffi cult to d evelop. A n in novative method specifically developed to identify the sali nity tolerance of the aquatic life inhabiting the area of given seawater desalination plant d ischarge was d eveloped at the Carlsbad seawater desalination demonstration plane in California. This method includes the following fo u r key steps: 1. Determination of the T est Salinity Range; 2. Identification of Site-Specific T est Species Inhabiting the D ischarge Area; 3. Biometrics Test at Average D ischarge Salinity; 4. Salin ity T olerance T est At Varying Concentrate Dilution Levels.

Determining Test Salinity Range T he first step of the sali nity tolerance evaluatio n (ST E) method is to define the

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AUGUST 2007 67


technical features

minimum and maximum T DS concentrations that are projected to occur in the area of the d ischarge after t he start up o f plant operations. T h is salinity range should be established taking under consideration the effect of mixing and associated d ilu tion in the area of the discharge as a result of the site-specific natu ral hydrodynamic forces in the ocean (currents, winds, tidal movements, temperature differences, etc) as well as the mixing energy introduced with the desal ination plant d ischarge d iffuser system. If the desalination plant concentrate is d iluted wirh another d ischarge (i.e. cooling water fro m power plant or wastewater treatment plant effiuent), p rior to the exit from the ou tfall in to the ocean, chis addi tional dilution should also be accounted for when establishing the salinity range for which the salinity tolerance of the aq uaric species is assessed. Because of the complexity of the various facrors that impact the mixing and d ilutio n of desalination plant concentrate with the am bien t ocean water, especially for large projects (i.e. projects with d ischarge volume of 1 MGD or higher), rhe actual salin ity range that would occur in the area of the d ischarge is recommended co be delermined based on hydrodynamic modelling. As a minimum, the salinity rest concen trations recommended co be used are: rhe T DS concentration at the middle of the water colu mn and the middle of the zone of initial d ilut ion (ZID); rhe maximum seabed salinity concentration at the edge of the ZID . The ZID is d efined as the area of rhe ocean within 1,000 fr fro m the point of t he desal ination plant d ischarge.

Identifying Test Species T he purpose of rhe seco nd step of rhe STE method is to identify the most sensitive, site-specific species chat would be ind icative of the salinity tolerance of the aquatic flora and fau na in the area of the desalination plant d ischarge. These species are used for the Biomerrics and Salinity T olerance T esrs. Ar least three species are recommended to be selected for the tests: one rep resentative for the fish population in the area, one fo r the invertebrate population and one for macro-algal population (i.e. kelp, red alga, ere), if such species arc present and occu r in signifi cant n umbers. The selection of the specific rest species should be completed by an expert marine biologist who is very fam iliar with rhe site-specific aquatic fl ora and fau na in rhe area of the desalination plant d ischarge. The test species should be selected based

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on : (1) presence and abundance in the area; (2) environmental sensitiviry (i.e. endangered/ protected marine species are fi rst p riority); (3) sensitivity to salinity in the range projected to occur in the discharge; (4) signifi cance in terms of commercial and recreational harvesting/fishing.

The Biometrics Test The p urpose of the Biometrics Test is co track how well the ind icative rest species wi ll hand le a long-term steady-state exposure co the elevated average discharge salinity char will occu r in the middle of the zone of initial d ilution after the desalination plant is in o peration. T he Biometrics Test is recommended co be completed in a large marine aquarium (rest tank) in which the desalination plant concentrate is blended with ambien t seawater co obtain salinity equal to that projected to occur in the midd le of the Z ID in the ocean for at least 95% of the rime. T h is salinity level should be maintained in the aquarium fo r the du ration of the rest. I n add ition, a second aquarium (control tan k) of the same size and number and type o f rest marine organisms should be employed , with the main d ifference chat chis rank should be fi lled up with ambient seawater collected from the area of the discharge. T he control tan k should be operated in parallel with rhe rest rank and observations from this tan k are used as a base fo r comparison and statistical analysis. O nce rhe salin ity in the aquariums is set to target levels, t hey should be populated with

Journal of the Australian Water Association

t he selected test species and key bio metric parameters (appearance; willin gness co feed; act ivity; and gonad prod uction) of these species should be monirored frequenrly (min imum every two days) by an expert marine biologist over a prolonged period of rime (minimum of three months, preferably five or more months) . Percen t weight gain/loss and ferti lisatio n fo r one or more of the rest and control organisms should measured as well. Ar rhe end of the rest, the q ualitative and quantitative bio metric parameters of the marine species in the test and control tan ks should be com pared to identify if the species exhibit statistically sign ifi cant differences - especially in terms o f weight gain/loss and fert ilisation capabilities.

The Salinity Tolerance Test The main purpose of the salin ity tolerance test is co establish if the selected test species will survive the extreme salinity cond itions chat may occur with in rhe ZID and on the ed ge of the ZID , and if these organ isms will be able to retai n their capacity to reproduce after exposure co these conditions for a length of t ime char is expected co occur in full scale operations u nd er worse-case scenario . The rest species should be exposed co several blends of concentrate and ambient seawater char can occur within the range of the discharge salin ities. The low end of the range should be the average salinity in the Z ID (middepth) and the high end should be the maximum salini ty above the seabed at the boundary of the ZID (i.e. 1,000 ft from the point of the d ischarge) .


technical features

Sim ilar to the Biomet rics Test, this experiment includes two sets of aquariums for each salin ity co ncentration - a series o f rest tanks, one fo r each test salin ity level, and a control rank. The d uration of the Salinity Tolerance Test should be d etermined by the length of occurrence of the worst-case d ischarge salinity scenario. Th is d u ration should be established based on the results from the h ydrodynam ic modelling o f the desalinatio n plant discharge. Usually, extreme salin ity discharge conditions are not expected to contin ue for m ore than two weeks. H owever, if this is likely in specific circumstances, than the length of the study should be extended accord ingly. Starting from the low end of the salin ity concentration, individ ual rest ran ks should be set for salinity incremen ts of 1,000 mg/L until the maximum test salinity concentration is reach ed.

Application of the STE Method for the Carlsbad Desalination Project The STE method described above have found practical application for the 200 ML/d (50 MGD) Carlsbad seawater desalination p roject, located in Southern Californ ia. This project includes d irect connection of the desalination plant intake and d ischarge facil ities to the discharge outfall of an adjacently located coastal power generation plant using seawater for once-th rough cooling (see Figure I). T he power plant has a total of five power generators and depend ing on the number of units in operation pumps between 800 ML/d and 3,280 ML/d (200 M G D and 820 MGD) of cooling water through the condensers. The warm cooling water from all condensers is d irected to a common discharge tunnel and lagoon leading to the ocean . T h e fu ll-scale desalination facility is planned to tap to chis discharge tun nel fo r both desalination p lant feed water and for dischargi ng h igh-salin ity concen trate downstream of the intake area.

Tobie 1. Marine Species Used for the Carlsbad Biometrics Test.

2 3 4

5 6 7

8 9 10 11 12 13 14 15 16 17 18

Scientific Name

Common Nome

Number of Individuals Per Species

Paralichthys californicus Paralabrax clathra fus Paralabrax nebulifer Hypsoblennius genii/is Strongylocentrotus Fronciscanus Strongylocentrotus purpuratus Pisaster ochraceus Asterina miniata Parastichapus californicus Cancer productus Crassadoma giganfea Haliofis Fu/gens Megathura crenulata Lithopoma undasum Cypraea spadicea Phragmalopoma californica Anthropleura eleganlissima Muricea Fruticasa

California halibut

5 juveniles

Kelp bass

3 juveniles

Barred sand bass

3 juveniles

Boy blenny

5

Red sea urch in

4

Purple sea urchin

14

Ochre sea star

3

Bot star

3

Seo cucumber

2

Red rock crab

2

Giant rock scallop

3

Green abalone

3

Giant keyhole limpet

3

Wavy turban sna il

3

Chestnut cowrie

3

1 colony

Sand castle worm

4

Aggregating anemone Brown gorgonion

1 colony

plant and the power p lant would be between 35 ppt to 40 ppr The average salinity in the m iddle of the ZID is projected to be 36 ppt. T herefore, the Biometrics Test was completed for this salin ity, while the test range for the Sal in ity T olerance Test was between 37 ppt to 40 ppt with 1 ppt increm ents. Both tests were executed by an expert marine biologist very fam iliar with the local fl ora and fau na in the area of the future desalination plant discharge.

is p resented in Table I. The Salinity Tolerance T est was com pieced using three local species which are known to h ave h ighest susceptibility to stress caused by elevated salinity: (1) the purple sea urch in (Stronglyocentroutus purpuratus), Figure 2; (2) the sand dollar (Dendraster excentricus), F igure 3; and (3) the red abalone (Haliotis rufescens), Figure 4.

A list of the 18 marine species selected for the Biometrics T est fo r the Carlsbad Project

The Biometrics Test was continued for a period of 5.5 months. T he results of th is

The Biometrics and Salinity T olerance T ests were completed in 110-gallon marine aquariums (Figure 5).

Water collected from one end of the power plant d ischarge can al would be conveyed to the desalination plant to prod uce fresh water and the concen trate from the desalination plant would be returned into the sam e discharge canal, ap proximately 270 m eters d ownstream from the poin t of intake. The d esalin ation plant concen trate, which would have apptoxi mately two tim es th e salinity of the source seawater (68 ppt vs. 33.5 p pt) would be blended with th e remaining cooling water discharge of the power plant and conveyed to the ocean for disposal. T he salinity range of the m ixed discharge from th e Carlsbad seawater desalination

Figure 3. Sa nd Dollar. Journal of the Australian Water Association

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AUGUST 2007 69


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test indicate that all organisms remain healthy throughout the test period. No mortality was encountered and all species showed normal activity and feed ing behaviour. The appearance of the individuals remained good with no changes in colouration or development of marks or lesions. The d uration of the Salinity Tolerance Test for the Carlsbad project was 19 days. The three test species had a survival rate of 100 %, which confi rms that they have adequate salinity tolerance to the desalination plant discharge in the entire range of operations of the desalinatio n plant (i.e. up to 40 pp t). All individuals of the three tested species behaved normally during the test, exhibiting active feeding and moving habits. In summary, the Salinity Tolerance Evaluation Method applied to the Carlsbad seawater desalination project confirms that the elevated salinity in the vicinity of the plant discharge would not have a measurable impact on the marine organ isms in this location and these organisms can tolerate the maximum sali nity of 40 ppt that could occur in the discharge area under extreme conditions. Additional acute and chronic toxicity studies completed subsequently for this project using the United States Environmental Protection Agency's standard whole effluent toxicity (WET ) test have confirmed the validity of the new STE method. WET testing using Abalone (Ha!iotis ruefescens) showed that the chronic toxicity threshold for these species occurs at TDS concentrations of over 40 ppr. An acute toxicity test completed using another standard WET species, the Topsmelt (Atherinops affinis), indicates that the

Figure 4. Red Abalone.

salinity in the discharge can reach over 50 ppt on a short-term basis (one day o r more) without impacting this otherwise salinitysensitive species. The results of the salinity tolerance evaluation completed for the Carlsbad desalination project were well accepted by the state and local regulatory agencies responsible for environmental p rotection in California. These results were also used for the environmental review and permitting of the 50 MGD Huntington Beach desalination project, which is developed by Poseidon Resources in parallel with the Carlsbad project. In August 2006 both projects received approvals for discharge

their concentrate to ocean. In addition, the innovative STE method described herein was recognised by the American Academy of Environmental Engineers, which awarded Poseidon Resources the 2006 Grand Prize for Applied Research for work com pleted at the Carlsbad desalination demonstration plant, including the STE studies. In September this project has also received the 2006 Global Grand P rize in the category "Applied Research Projects" category by the International Water Association - the highest recognition for innovation in the water and wastewater research field worldwide.

Summary and Conclusions The innovative Salin ity Tolerance Evaluation (STE) method enables the assessment of both the long-term and the short-term impacts of a given desalination plant discharge on the marine organisms in the vicinity of the discharge. The method has won awards and was used successfully for permitting the ocean discharges of rwo large seawater desalination projects in California, USA - the 200 ML/d (50 MGD) Carlsbad and Huntington Beach desalination plants.

The Author Nikolay Voutchkov (nvoutchkov@

Figure 5. Carlsbad Biometrics Test Tank.

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poseidonl.com) is Senior V ice P resident Technical Services, Poseidon R esources Corporation, Stamford, California, and a frequent keynote speaker at Australian confe rences on desalination.


technical features

recycled water

RISK MANAGEMENT: BOVINE JOHNE'S DISEASE AND WATER RECYCLING T Anderson Summary

The catchment of South East Water's Pakenham sewage treatment plane includes a car tie sale yard and an abattoir. T reared effluent from rhe plane is used to irrigate pasrure grazed by dairy cattle. There is a consequent possibility char cattle diseases can be transmitted to the grazing animals. Advice from the Victorian Insrirute of Animal Science indicated that the cattle co ndition of most concern was Bovine Johne's Disease (BJD). T his disease is common in dairy herds in a num ber of scares withi n Australia and management practices are well developed and widespread in the dairy industry. The disease reduces milk production in mature animals and affects the value of both the carcass and infected land . South East Water has undertaken a number of actions to quantify and manage the incremenral risk of BJ D occurring at Pakenham as a result of water recycling. These actions include obta ining opi nion from persons expert in BJD, sponsoring research projects, obtaining advice on the possible link with Crohn's d isease in hu mans and legal advice. The outcome is char there is no evidence of a material ri sk to either humans or mature cattle although the risk co susceptible animals such as calves cannot be d iscounted. As a consequence, measures designed co eliminate exposure of calves to recycled water have been incl uded in agreements with recycled water cuscomers. Introduction

South East Water is a government-owned retail water company formed in 1995 with about 1.3 m illion cuscomers in the south eastern suburbs and outlying areas around Melbourne. The Company purchases potable water from Melbourne Water Co rporation, delivers it to customers and collects the consequent sewage and trade waste. There are two other similar retail water companies in Melbourne - Yarra Valley Water and City West Water.

Quantifying and managing the risk of disease transmission.

Cattle on pasture irrigated with treated sewage at Pakenham.

In South East Water's case, about 90% of the sewage and trade waste is retu rned to Melbourne Water for treatment at one of the two major facilities serving the central metropolitan region. The remain ing 10% of waste arises in townships remote from rhe central system and is treated in small facilities owned by South East Water and with capacities in the range 0.5 co 15 ML/day. When these plants were firs t established, the effl uenr discharged co local water courses which drained inco either Port Phillip Bay or Western Pore. Th is approach became inco nsistent with government policy expressed in Stare Environment Protection Policies first published by the Viccorian EPA during the 1980s. These policies consistently favour recycling of effluent from sewage treatment plants co land wherever "practicable". In response to this policy position, South East Water has sought to eliminate discharge co inland water courses at each of its treatment planes. Effluent recycling represented a predomi nantly new activity for the Melbou rne water industry at rhe time when South East Water was formed as a separate

organisation in 1995. As a consequence, South East Water sought co identify risks associated with ch is new activity and develop appropriate management systems. The purpose of rhis present paper is to describe South East Water's general approach to risk management and rhe speci fie actions taken to manage the possibility chat effluent from the Pakenham sewage treatment plane could increase the incidence of disease in cattle. General Approach

South East Water's general approach to management of risk is based on the concept char compliance with regu lations is a necessary but not always sufficient bas is for / 1 managing risk. For example, regulations and guidelines may not be adequate to manage either well recognised risks or specific issues arising from unique or unusual circumstances. In such circumstances, the obligation under Civil Law to exercise due care requires that all reasonable efforts are made to identify, evaluate and mitigate the risk. Because of chis general approach to management of risk, South East Water

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technical features

recycled water initially sought to identify aspects of proposed water recycling schemes that were unique or unusual. Investigation of these matters was then undertaken using a combination of literature sources and co nsul tancies. The p ractices at existing sites with similar circumstances and a long track record of satisfactory operation were also of particular interest since this can be an effecti ve way o f identifying satisfactory management arrangements. Thus, the desk top work based o n literature and consultancies was supported by visits to recycling sites and regu lators in Australia and also overseas in Israel and USA where there is a long history of water recycling. A unique aspect of p roposals to irrigate pasture grazed by cattle with effluent from the Pakenham sewage treatment plant arises because of the p resence of cattle waste in the plant in fl uent. T he possibility that this situation would increase the probability of disease occurring in the grazing h erds was clearly an unusual issue which may not have been envisaged by the normal regulatory framework. Advice from the Victorian I nstitute of Animal Science, which is a bran ch of the V ictorian Government Department of Natural Resources and Environment, indicated that the only disease worthy of detailed investigation was Bovine Johne's Disease (BJD).

Bovine Johne's Disease BJD is a chronic bacterial infection caused by a mycobacterium (M. paratubercolosis) and it is present in about 25% of Victorian dairy herds. The d isease is normally co ntracted by calves grazing pasture contaminated with faecal material from infected cattle and the incubation period prior co development of clinical signs is protracted (i. e. typically 4 to 5 years). The exposure risk is not insubstantial because a clinically affected animal typically discharges about 5xl0 12 bacterium per day. A sub-cli nically affected animal discharges a lesser amount of about 8x l 06 bacterium per day. Cl inical signs associated with the disease are persistent diarrhoea and emaciation. However, cattle remain b right and exhibit a n ormal appetite during the initial stages of infection prior co exhibition of clinical signs. The disease is invariably fatal once cl inical signs develop but not all infected cattle develop clinical symptoms. The reason fo r this difference in response is unknown and there is no treatment fo r the disease. The incidence of BJD is not uniform throughout Australia. Areas where the disease is particularly p revalent include

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Viccoria, Tasmania, South Australia and New South Wales whereas Western Australia and Northern Territory are considered to be disease free. The Viccorian Livestock Disease Control Act requires that the suspected presence of BJD is notified to animal health staff at the Department of Natural Resources and Environment. Penalties apply if persons aware of the suspected presence of BJD fa il to carry out chis notificatio n. If the p resence of BJD is confirmed, then rhe land is regarded as contami nated. T his status remains unless the land is descocked of all susceptible animals for a period of 12 months. Clinically affected animals must be destroyed on the fa rm or sent to a knackery. BJD is of significance to the dairy industry because milk production drops in clinically infected animals and the carcass has no value because it must be sent co a knackery. Th ere are also a number of indirect effects such as a reduction in the value of co ntaminated land and constraints on the movement of animals. Mature animals are widely regarded as resistant to infectio n and the basis of all BJD man agement programs is to isolate cattle less than one year old from potentially contaminated pasture.

Pakenham Sewage Treatment Plant Pakenham sewage treatment plant is a 5 ML/day secondary fac ili ty which includes maturation lagoons and chlorinatio n for disinfection. The plant is located about 80 km south-east of central Melbou rne in a rural area with a traditio nal emphasis o n dry land dairy farm ing. The plant serves the cownshi p of Pakenham as well as a small industrial zo ne. Two of the signifi cant industrial businesses d ischarging trade waste inco the Pakenham system include a cattle saleyard and an export abattoir. In 1995, Sou th East Water committed co recycling 90% of the plant effluent co land by the year 2000. This commitment required a plant upgrade to accommodate expected growth in flows, a 900 ML storage reservoir to store effluent in winter and an effluent pump station and piping system co provide irrigation water co potential customers. These works were completed by 1998 at a cost of around $ 13 M. Agreements were also formed with a number of customers to recycle efflu ent from the plant by irrigating land. Inevitably, a number of these customers were dairy fa rmers because this was the most common farming activity in the district.

Journal of the Austra lian W ater Association

A feature of the plant is that it includes two parallel process streams and some inflows only receive treatment in an aerated lagoon and maturation ponds for about 20 days b efore chlorination (CT of about 60 mg. min/L) and application directly to dairy pasture as a Class C effluent. T he Victorian EPA guidelines for use of recycled water require that Class C effluent has a median composition of less than 1000 E.coli/l00ml, 20 mg/L ofB OD and 30 mg/L of suspended solids.

Actions Taken by South East Water to Assess the Risk of BJD Initial assessment

The prefe rred approach to identification of approp riate management practices for BJ D at Pakenham was to identify a similar situation elsewhere with a long hiscory of satisfactory operation. However, it proved very diffi cult to locate an existing recycling sch eme where the risk had b een assessed and was being specifically m anaged. The only similar scheme based on irrigation o f dairy pasture identified worldwide was in a region immediately to the north of San Francisco. H owever, a visit to the sire indicated that the effluent was of tertiary quality (i .e. the process stream included a particulate filtration step after secondary treatmen t) and very highly chlorinated. Additionally, the possibility chat water recycling cou ld increase the incidence ofBJD had not been recognised and there were no management practices specifically designed to limit this possibili ry. Thus two specific furth er steps were taken co prepare an initial assessment o f the risk due to the possible presence of BJD in effluent at Pakenham. The first of these involved seeking advice from th e Office of the C hief Veterinary Officer in Victoria. The 1996 advice received from this office states that the risk of adult cattle contracting BJD at Pakenham is "very low co n egligible". South East Water also engaged the Victorian Institute of Animal Science co prepare a desk top evaluation of potential risks associated with BJD at Pakenham. Their 1996 report indicated that there was no quantitative data in the literature abou t the removal of M. paratubercolosis in sewage treatment p lan ts. H owever, there are reports in the literature which indicate that the bacterium is very resistant to chlori nation and an exposure of up to 2400 mg.min/Lis required to achieve complete disinfection in "waste water". Furthermore, the organism can survive for more than 8 months in moist faeces and for a similar


technical features

recycled water period in water although ocher studies have demonstrated that the organism does nor survive 100 hours of exposure to sunlight. The resistance to the chlorine dose in the recycled water and the protracted survival period in moist conditions indicate that reduction to safe levels by the treatment process will be essential to reduce the dose of bacteria received by grazing an imals. T h e authors prepared an approximate assessment of the likely dose of the BJD bacterium assimilated by cattle grazing irrigated pasture at Pakenham. This assessment assumed: • O nly su bclinically affected animals contributed waste to the plant. The assumed incidence of such animals was 0.5% and it was also assumed that cattle were only p resent in the saleyard or abbatoir fo r one day before processing. • Raw sewage concentrations of M. paratubercolosis would be reduced by 1 log (base 10) d u e to "settling" in the treatment plant, a further 2 logs due to detention in the maturation ponds and a further I log due to the 5 day withholding period between cessation of irrigation and commencement of grazing at Paken ham. • Only I 0% of the bacterium applied to pasture were "available" to cattle because of th e effects of die off on the pastu re. The concl usion arising from this assessment was that an adult animal grazing irrigated pasture at Pakenham would ingest an average of l organ ism every 100 days. This result allowed the au thors to conclude that the chance of cattle infection occurring th rough recycling effluent "is m inimal if risk management strategies are properly instituted". These strategies have the objective of ensuring that calves less than I year old are not exposed to M. paratttbercolosis through contact with either infected cattle or in fected effl uent. The report also considered che possibil ity that exposure to the BJD bacterium could cause disease in humans. The o nly d isease in humans w here a possible link with BJD has been postulated is Crohn's Disease. T his condition is a chronic inflammatory bowel d isease that is debilitating but rarely fatal. However, the report indicated chat a clear link has not been established between Crohn's disease and BJD.

Refinement of the initial assessment

Disease in cattle The advice described above was nor based on quan titative data on the concentration of the BJD bacterium in sewage o r effluent ac Pakenham and was also limited by the paucity of data about the durability of the

bacterium on pasture. South East Water initially sought co address chis deficiency by engaging the Victorian Institute of Animal Science to develop a method for enumerating M. paratubercolosis in sewage samples and applying it to the particular circumstances at Paken ham. A method was successfully developed after a protracted development period and the 2002 report of chis work indicated char che bacterium was detected in about 15% of trade waste grab samples obtained from the cattle sale yards. The average value of these results was about 7900 baccerium/L. No sampling of trade waste from the abattoi r was undertaken because the pre-treatment process u pstream of the discharge point included an aerated reactor and extensive maturation ponds. Consequently bacterial n umbers would be much lower than fo r the sale yards . Similar work at the sewage treatment plant inlet only detected the bacterium in 1 of the 565 samples tested and fai led to detect the organism in any of 237 samples of plant effluen t. These resu lts indicate char the sensitivity of the test method was inadequate to detect the low concentrations of M. paratubercolosis at both locations. To confirm chis explanation, the Institute of Animal Science prepared an estimate of likely concentratio ns based on rhe trade waste data. These estimates assumed: • D ilution was rhe on ly mechanism red ucing concentrations in the sewerage system and • There were two mechanisms reducing bacterium n umbers in the treatment process - sedimentation and die off. The Institute argued chat the bacterium would absorb on to solids and thus the effect of sedimentation could therefore be estimated by assuming bacterium numbers were proportional to rhe reductio n in suspended solids concentrations. The effect of die o ff was quantified by assuming a linear relationsh ip with time and relying on a published result wh ich showed chat viable bacterium numbers in a moist slurry dropped to zero after 6 months. The outcome was char calculated values averaged about 220 organisms/L at the plant inlet (compared with a limit of detection of 10 0) and about 20 organisms/Lat the plane outlet (limit of d etection 20). The authors were not able to explain rhe co nsistent failure to detect rhe BJD bacterium at the plane inlet and ou tlet given chat expected numbers were above or comparable to the limit of detection in both cases. An explanat ion favo ured by the authors was that actual values were lower than estimated and a

value of 5 organisms/L was adopted for the purposes of assessing the probability of infection in cattle grazing irrigated pasture. This probability can be quantified ro some extent since typical irrigation rates at Pakenham are about 2ML/ha/year, resulting in the application of say 107 organisms/ha over an irrigation season if the low chlorine doses at Pakenham are assumed to have a negligible effect. It is possible chat a large proportion of these organisms survive for some time given the reported durability of M. paratubercolosis in moist conditions. Interpretation of this result is complicated by the absence of dose response data fo r cattle bur the literatu re indicates that an oral dose of I 00 bacterium, repeated once per week over IOweeks, can cause infectio n in lambs. T his caused rhe authors to conclude char rhe possib ility chat effluent from Pakenham could cause infection in susceptible animals "could not be ruled our" . However, the expected incidence of M. paratubercolosis on irrigated land is low compared w ith expected levels on land grazed by clinically affected animals, which can deposit u p to 10 12 organ isms per day. le is therefore likely char there is no material increase in the probability of illness in mature cattle which are generally regarded as resistant to infection. The key aspects of rhe analysis above are the constraints imposed by the limit of detection in plant effluent and the absence of dose response data fo r calves. The analysis also failed to allow fo r the effects of chlorination, effluent storage and d ie off on pasture b ut these limitations are probably less significant given the results of previous work reported in the literature. Discussion with the authors indicated that further quantification of the actual concentration of M. paratubercolosis in effluent wou ld require resting of impractically large volumes to improve the detection limit. A su bsequent consultancy with the Victorian Institute of Animal Science indicated that the infectious dose for BJD has not been determined for cattle or calves and is not a priority research area in the shore term. T he probab ility of a BJD outbreak in a dairy herd was further assessed by providing the 2002 report from the Victorian Institute of Animal Science to the Office of the Chief Veterinary Officer. The Office subsequently indicated chat "our assessment has not changed" from that in 1996 which indicated that the "risks are low to negligible".

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technical features

recycled water Disease in humans

Negligence

â&#x20AC;˘ Negligence. The evaluation work and

Consultants Ausvet were also approached to provide an assessment of the likelihood that M paratubercoiosis causes disease in humans. Ausvet has an ongoing association with national Johne's Disease programs and also sough t specialise advice from an Associate Professor in che Department of Medicine at the U niversity of Syd ney.

The BDW report indicates chat a successful action in negligence wo uld require a demonstration, on the balance of probabilities, chat BJD was caused by exposure to irrigation water and not from some ocher source.

expert opinion described above indicated char it is very unlikely chat effluent from Pakenham will cause an outbreak ofBJD in mature cattle grazing irrigated pasture. T h is outcome nocwichscanding, South Ease Water assessed a number of options for furth er reducin g the prevalence of che bacterium in effluent at Pakenham. These options included enhanced on-site trade waste pre-treatment, diversion of affected trade wastes to another treatment facil iry and enhanced chlorination. The net present cost of each of these options is about $1M. This is much greater than the foreseeable loss co a dairy fa rmer fo llowing an outbreak ofBJD. For this reason and because of the low probability of BJD occurring, South Ease Water has ad opted the position chat it would not be acting reasonably co incur this additional expenditure for chis purpose.

The Ausvet report concluded that the only h uman disease for which the BJD mycobaccerium "has been p roposed as an important causal factor at a population level is ..... Crohn's disease", which is p resent in the Australian population at a p revalence of about 50 cases per 100,0 00 people. The Ausvec report indicates char chat there has been extensive research worldwide seeking to resolve the possibil ity of a causal link between BJD and Crohn's d isease. This research received renewed impetus fo llowing isolation of che BJD mycobaccerium from a small nu mber of patients with Crohn's disease in the USA in 1984. There have been a number of studies, however, which provide evidence against an association between the two condi tions. For example, epidemiology studies do nor demonstrate a higher incidence of Croh n's disease in farm workers with a high exposure to potentially infected animals and faeces. Furthermore, similar studies d o not show a correlation between che prevalence of the two conditions. For example, che incidence of Crohn's d isease is high in Sweden but BJD is rare. The overall body of research has been summarised in number of reviews over the lase decade. The fo llowing co nclusion reached by the Australian Government's D epartment of H ealth and Ageing in mid 2003 is typical of che findings of these reviews: "Although che cause of Crohn's d isease is still uncertain, there is no substantiated causal link between Johne's disease and Crohn's d isease". The Ausvec report also indicated char Ausvec had nor been able co identify any Government or industry warning issued to fa rmers specifically concerning occupational health and safety and BJD in Australia.

Risk Mitigation Legal advice South East Water received advice fro m lawyers Blake D awson Waldron (BDW) in 2003 concerning che potential liability associated with supply of irrigation water possibly containing M. paratubercoiosis. T his advice indicates char the most significant risks are liability for actions in negligence and for misleading and deceptive conduce.

If causation was demonstrated, chen South East Water would become liable due co a breach of its d u ty of care if it could be proven chat the infection occurred because of an ace or omission which Sou th Ease Water should have fo reseen and char South Ease Water failed to do what a reasonable person would have done co prevent such an act or omission. In such a case, South Ease Water would be liable for all loss which is che reasonably foreseeab le resul t of its negligence. Misleading and deceptive conduct The BDW report indicates chat the definition o f misleading and deceptive conduce in che Trade Practices Act (TPA) includes a corporation falsely representing chat go ods are of a particular standard . Contravention of these requirements allows a plaintiff co seek damages and ocher remedies provided by the T PA. Additionally, a defendant may be fined up co $1.1 million per contravention.

Risk mitigation actions As a consequence of the work described above, South East Water undertook a range of actio ns co m anage the risk posed by the possible presence o f M. paratubercolosis in effluent at Pakenham. T hese actions included:

â&#x20AC;˘ Recycled water agreements. Recycled water agreements were modified to include a number of specific requirements co isolate calves from recycled effluent. South Ease Water monitors compliance with these requirements.

Water Advertising To reach the decision-makers in the water field, you should consider advertising in Water Journal, the official journal of Australian Water Association. For information on advertising rates, please contact Brian Rault at Hallmark Editions, Tel (03} 8534 5000 or email brault.rault@halledit.com.au

74 AUGUST 2007 Water Journal of the Australian Water Association

â&#x20AC;˘ Misleading and deceptive conduct. Information about the possible presence ofM. paracubercolosis at Pakenham and the possible implications was provided co recycled water customers and an acknowledgement chat such information had been provided was obtained.

Conclusion Compliance wich che regulatory framework is not always an adequate approach co risk management and there is an obligation to undertake all reasonable efforts to identify, evaluate and mitigate risks. This obligation has led South Ease Water to undertake a derailed evaluation of the probability of BJ D occurring in cattle grazing pasture irrigated with effluent from Pakenham treatment plane. The evaluation has involved a n umber of expert consulcancies and a sponsored research program. This work has demonstrated chat the probability of BJD occurring in mature animals is negligible and there is no substantiated link between BJD and disease in humans. However, the possibility of a risk co susceptible animals such as calves cannot be discounted and management controls have been adopted to mitigate chis risk. Despite che low probability of BJD occurring at Pakenham, South Ease W ater evaluated a nu mber of options co further mitigate che risk. These evaluations indicated chat the cost of these options was much greater than foreseeab le loss should BJ D occur. Implementation of these options has therefore been regarded as unreasonable, particularly because the p robability of BJD causing harm is so low.

The Author Dr Terry Anderson is Technical Projects Manager, South Ease Water Limited. Email: cerry.anderson@sewl.com.au


A STATE WATER PLAN FOR WESTERN AUSTRALIA M Blais, H Forte Abstract In May 2007, the Western Australian Government released State Water Plan 2007. It summarises the State's existi ng knowledge of water resources, use, experience of climate change and fo recasts demand growth in major seccors. The Plan outlines water policy and plan ning frameworks to integrate reforms at state and national levels. State Water Plan 2007 outl ines over 100 priority actions co im p lement these changes and sup port the sustainable enjoyment of water resou rces in W estern Australia.

Background Water is highly valued by Western Australians. le is essential co the environment and supports the enormous biodiversity of our native flora and fauna. Water is fundamental co life and public health, d rives and facilitates economic developmen t and provid es a variety of social, sporti ng and recreational opportunities. Water has cultu ral and spiritual value, particularly for Indigenous people.

State Water Plan 2 007 is a high level strategic document chat encompasses a vision and principles for water managemen t chat apply co urban, town , rural and remote communities . While chis was a major challenge in terms of consultatio n and scope, it reflects the community's desire co better understand the range and scale of water issues in the Seate and for all seccors to work cogecher co secure our water fucu re. The Plan seeks to integrate a range of water resources issues, for chis vase scare that accou nts for more than o ne third of Australia's land mass. A whole o f water cycle approach has been adopted with a planning horizon to 2030. The Western Australian State Govern ment has given water and the management of water resources strategic priority since

Extensive community consultation and 13 government agencies involved.

200 1. T h is w ill continue into the future given climate change and variability, resource scarcity and contin ued increases in demand.

Building on Strong Foundations State Water Plan 2007 has built o n the fou ndat ions of extensive commun ity involvement over che past five years. In 200 2 a series of W ater Forums were h eld throughout the Seate, culminat ing in a Water Symposium and the release of the Scace Water Strategy in February 2003 . This was a land mark in Government and commun ity collaboration co invest in water use efficiency, research and new sources.

• Extensive consultation on the Water Reform Program that led co new policy directio ns fo r water entitlements, planning, metering, trading and cost recovery • Independent reviews of numerous alternative water sources including options from the Fitzroy an d Ord river systems and the redevelopment of the Wellington D am in Collie .

Governance and Community Engagement

State Water Plan 2001 highlights over 80 major ach ievements in water resource management in Western Australia since the release of the Strategy. These include:

The initiative to develop a State Water Plan was launched by the then Premier, Hon G eoff Gallop, in September 2005 with a commitment co extensive community consultation. As ou tlined, the state-wide nature of the Plan and the broad range of stakehold er in terests provided a significant challenge in chis regard.

• A 20 % reduct ion in scheme water use in Perth over a five year p eriod without the need for a coca! sprinkler ban or severe restrictions

Consul ration was p rimarily delivered through State Water Plan 2007 and Water Reform Program (refer previous section) chat operated concurrently in 2006.

• An in crease in statewide water recycl ing from just over 2% co almost 14% in five years

State Water Plan 2007 was supported by che consultation mechanisms o utlined in Table 1, com p leted over an eighteen-month period.

• Launch o f the Scace Grou ndwater Investigation p rogram and com p letion of initial priority investigations • Over 270, 000 Wacerwise rebates granted by the Scace Government co promote water use efficie ncy, resulting in over 60 gigalicres in water savings • N umerous integrated catch ment man agement and salinity reduction strategies implemented, incl uding the national award winning Torbay Watershed program

The results of these processes, including summaries of meetings and community workshops and all public submissions, were made available on a Government website, during p roject d evelopment. I n add ition co consultatio n w ith the commu nity and interested groups, integratio n across Government was required co ensure chat the range of issues and solution s were co nsidered and addressed. The Scace Water Plannin g

Table 1. Consultation mecha nisms. Process

Role

Engagement

State Water Planning Review Panel

Four member independent panel to advise Government and critique Plan development

Three meetings during project development

State Water Forum

Consult with representative stakeholder organisations (over 40)

Five forums during project development

Comm unity workshops

Engage and consult with the community on values and options with regard to water policy

25 workshops in all reg ions of the State

Public submission periods Formally invite and consider comment on draft documents, including priority actions to implement the Water Policy and Planning Frameworks

Journal of the Australian Water Association

Two submission periods totalli ng 24 weeks

Water

AUGUST 2007 75


technical features

water supply Implementation Committee was convened wich representatives from 13 Government agencies, chaired by che project leader from the Department of che Premier and Cabinet. This Committee met monthly. The Minister for Water Resources, che Hon John Kobelke MLA oversaw the development of the Plan and provided regular briefi ngs co che Water Resources Cabinet Sub Committee, chaired by the Depu ty Premier and Treasurer, the Hon Eric Ripper MLA. The consultative process used co develop State Water Plan 2007 brought cogecher water experience from a wide range of policy, industry and community perspectives. The Plan was strengthened through chis engagement as ic led co an improved understanding of current issues, aspirations and options for the fu ture management of water resources.

Water Resources The Plan acknowledges the diverse range of surface water and groundwater systems in Western Australia. There is a need co protect and manage water quality and availability in catchments and wace1ways chat are impacted by changing land use and the sharing of water for use. Natu ral events, inclu ding droughts and floods, require t imely and flexible management responses. The sustainable yield of Western Australia water resources is estimated co be 11,515 gigalitres. These resources are a combination of surface and groundwater resources, wich groundwater accounting for over 50% of che sustainable yield . About half of these groundwater resources are located in fractured rock provinces chat are typically isolated, relatively small and do not lend themselves co large-scale development.

Table 2. Water resources availability in Western Australia (2005).

Sustainable yield (gigalitres)

Current allocation limit (gigalitres)

Canning Carnarvon Perth Officer-Eucla

827 244 1,937

357 78

Kimberley Pilbara

813 472 1,740 6,304

Yilgarn GROUNDWATER

271

0 8 191 509 1,690 321

1,054

16 312

5,211

4,409

l 650

ALL WATER RESOURCES

11 ,515

8,193

2,340

Only about 30% of current allocation limits statewide are used and in most areas of the Srace water resources are not yet fully allocated. There are areas where there is significant competition for water resources however, especially in che Pilbara, Metropolitan and Sou th West regions of the Scace. Where water systems are overused, State Water Plan 2007 gives priority co the restoration of these systems. The Plan includes actions co support increased investment in resource investigation and assessmen t, statutory water p lanning, providing legal securiry to water entitlements and more metering and monitoring. These practical measures will improve the integrated man agement of water resources for all Western Australians. Table 2 summarises the estimated sustainable yields, water resource availability and use of water resources in Western Australia.

Estimated use 2005 2,340 gigalitres

• Groundwater use

ell (I)

>- 1,500

ell

Adapting to Climate Change Western Australia has d ifferent climate zones rangi ng from tropical areas in the north, arid areas in the centre and a more temperate climate in the sourh. Over the past ten years, there have been n oticeable changes in climate, particularly in the southern half of the Srace. These changes are predicted co continue, resulting in lower rainfall and runoff and higher average temperatures. In addition co chis placing pressure on water security for use, impacts on ecosystems, water quality, recreational and other values are predicted. Climate modelling by CSIRO shows char average annual rainfalls are projected co decline in the South West of Western Australia (where more than 75% of the population resides) by as much as 20% by 2030 and 60% by 2070, compared with average recorded rainfalls co 1990. The Indian Ocean Climate Initiative has already identifi ed the followi ng regional climate trends for the Somh West of the State: • Increased average temperatures of 0.8 degrees Celsius since 1910 with most change occurring over the past 50 years • Average Indian Ocean surface temperatures have increased by 0.6 degrees Celsius • Over the past 35 years, the number of storms have decreased, bringing less rain

"'(I) L.

1,000

Estimated use 1980 749 gigalitres

0

500 0

83 29 316 1,449 3,784 2,952 402

L.

-~

1,472

3,160 440 1,610 l

f'."l Surface water use

"'iij 00

24 50 908

Timer Sea Indian Ocean South West Western Plateau SURFACE WATER

2,500

2,000

Estimated use (gigalitres)

l-----.---.-----.;;;;;;;;;;;;;;;....,---m11

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Figure 1. Historical water use in Western Australia.

76 AUGUST 2007

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Journal of the Australian Water Association

• Over chis same period, annual rainfalls decreased by 10% and winter rain fa lls have decreased by 15%. Mose strikingly, reduced rainfalls have resulted in decreases in flows to public water supply dams by more than 50% on average . In some areas, decreased recharge co aquifers has also occurred. In the


technical features

water supply metropolitan area, srreamflows have decreased by rwo thirds. The 2006 winter was one of the driest on record. State Water Plan 2007 has been informed by work completed in Western Australia ro understand and adapt ro these changes. Ir supports ongoing research into che nacure of climate change and impacts on other regions of rhe Stare.

that have been embraced by the community ro dare. T he most sustainable way ro meet growing demand differs by sector, user and location. T he environmental, social and economic impacts of a range of demand and supply alternatives need to be evaluated. Groundwater remains an important resource due ro irs • Agriculture 37% • Households 18% relative availability and proximity • Commerce and industry 16% Minerals and energy 26% to demand in most pares of rhe Public o pen space 3% Water Use in Western Scare. Increasingly, demand will Australia be mer through water Figure 2. Water use in Western Austra lia by sector. co nservation, efficiency and Figure 1 demonstrates rhar over rhe past 25 years, water use has recycling. The Stare is co mmitted Ord irrigation scheme may significantly to fu rther significa nt advances in these tripled in Western Australia. Groundwater increase sectoral water use in rhe order of areas, enabled by research, rebates and now accounts for almost three quarters of 400 gigalirres. industry partnerships. water used. Mining uses about 26% of all water in State Water Plan 2007 identified rhac Figure 2 summarises water use in Western Western Australia. The minerals and desalination and other trearment Australia by sector. The agricultural, petroleu m secto r was valued at over $40 tech nologies are economical options for mining and household sectors have high value water use. In 2006 rhe Water billion in 2005/06 and ic is a driving force different water needs and account for more Corporation of Western Australia in the local and national econo my. Gold chan 80% of all water use. More work is commissioned a 45 gigalicre desalination mining accounted fo r about half of all needed ro better understand rhe nature of plane, powered entirely by wind energy, to water use with iron ore and nickel being the water use in commerce and industry and augment public water supply fo r rhe major users. Importantly, about 60% next for public open space. State Water Plan Incegrared Water Supply Scheme. This of all water used by che sector is brackish ro 2007 commits to derailed actions to invest plant has built capacity and confidence in hypersaline and there is lirrle competition in this understanding in rhe next rwo years. desalination as a sustainable resource for rhe for this water. T he outlook is for conti nued strong growth future. There are ongoi ng changes to water in rhe economy and rhe State's popu lation, Shortly after rhe release of State Water Plan placing further pressure on existing demand in th is sector, due ro rhe relatively 2007, the Premier of Western Austral ia short life of many projects. The demand resources. announced the decision ro construct a forecasts for mining and energy will be While agriculture is rhe largest water user in second desalination plane, powered by influenced by national and state policies Western Australia (as in most other stares renewable energy, as Western Austral ia's and rhe nature of commercially viable of Australia) in 2005 ir accounted for only next major water source. In the mineral projects. Meeting rhe demand for 37% of all water used. Water use in announcement, rhe Premier, the Hon Alan water to support the iron ore ind ustry in agriculture in WA is predo minancly for Carpenter MLA, noted that the plant rhe Pilbara and Mid West regions of rhe high value horticul tural crops such as would have rhe capacity to deliver at least is a priori ty for Government and Stare grapes, fruit and vegetables, many of which 45 gigalirres per annum on com missioning private industry. are exported. Further, the Ord irrigation in 2011, wi ch che potential to increase scheme in rhe Kimberley accounts for 10% In Western Australia, households use abour production ro 100 gigalirres per annum. of all use and coincides with the largest 18% of all water. Of chis, about a quarter availability of water in a surface water of rhe demand is met from privately owned Water Policy and a Vision for Water system. garden bores that provide a sustai nable Resource Management water resource in most parts of rhe Stare. There is competition for water used in In response to the drivers of reductions in Outdoor water use in Western Australia is agriculture in rhe southern part of rhe tradi tional water resource availability and generally higher than in other pares of Stare, particularly in rhe Gnangara increases in demand, a Water Policy Australia due ro che sem i-arid cl imate and groundwater system north of Perth and the Framework has been developed (Figure 3) scarcity of summer rainfall in che populous Harvey irrigation area in rhe South West. co gu ide water resource management in southern half of the Stare. Opportunities for tradi ng within rhe Western Australia. T he framework: agricultural sector and to other sectors exist Water demand fo r household use wi ll • Provides strategic rationale fo r derailed and are being facilitated by policy and increase due to projections rhac fo recast a policies, action plans and strategies legislative changes. There is a need to 40% increase in che Stace's population by • Ourlines key concepts co implement improve the licensing and metering of use 2030 (an increase of more than 800,000 Government decisions on rhe Water in rhis secto r. people ro a total population of 2.8 million). Reform program Growth of water use by the agricultural Options are being evaluated ro seek co • Facilitates the implementation of the sector will be influenced by macro and constrain this demand, while preservi ng the National Water Initiative in a manner micro economic policy including water social, recreational and aesthetic amenities appropriate fo r Western Australia policy decisions with respect to charging for that greenspaces bring. Importantly, there is water use and management. In terms of • Ensures water plans address issues in che a need to continue to embed che context of shared whole of Stare objectives geographical development, expansion of rhe behavioural changes to outdoor water use Journal of the Australian Water Association

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AUGUST 2007 77


technical features

water supply â&#x20AC;˘ Ensures consistency of approach to water policy over time

Our precious water resources are managed and developed

â&#x20AC;˘ Builds a shared understanding of water resource management p rinciples.

in a sustainable manner to maintain and enhance our

The seven objectives of the framework support the vision for water resource management by building on the foundations of the State Water Strategy and the National Water Initiative to imp rove water resou rce securiry and certainty for users, the communi ry and the enviro nment.

natural environment, cultural and spiritual values, our quality of life and the economic development of the State. Deliver services for strong and healthy communities

Plan and manage

water resources sustainably

Water Policy objectives reinforce each ocher and work together to support water for ecosystems, recreational and cultural use, its vital role in developing our economy and the provision of safe, quality water services for healthy commu nities. Each o bjective has a number of policy statements that further outline the approach to water management in Western Australia. They include statements on a diverse array of issues including water sensitive design, communiry involvement, interests of indigenous co mmunities, impact of cl imate change, scientific knowledge base, water education, catchment management, energy use, water markers and trading, fir for purpose, resource development in remote areas and drinking water source protection.

Water Planning State Water Plan 2007 includes a Water Planning Framework (Figure 4) to deploy further strategic and derailed water planning. Water planning is a mechanism to imp rove certainty for the enviro nment, the community and all water users. The Water Planning Framework outlines water plans rhac are che primary respo nsibiliry of the Western Australian Department of Water. Water plans acknowledge the multiple objectives in water cycle management and potential and agreed cradeoffs between these objectives. Plans outline the actions, operating strategies and compliance practices to achieve agreed outcomes.

Protect ecosystems, water quality

and resources

environment and use

Figure 3. Vision and objectives for water resource management.

Statutory Water Management Plans will communicate decisio ns chat have legal obligations and can be enforced. They will be prescriptive to facilitate certainry. Derailed water plans to protect drinking water sources and manage drainage and floodplains will also be developed. Plans wi ll be written in a manner chat supports community involvement and understanding. Incegraced water management is a goal of strategic water management in Western Australia. Where poss ible , planning will be integrated to address the suscainabilicy of the resource, use, protect catchments and drinking water sources and manage ocher impacts.

Ir is important char water plans integrate with land use planning in a manner that avoids duplication and unnecessary delays in decision making.

Water Conservation, Efficiency and Recycling The Scace Water Strategy set a target to reduce Perch's co nsumption to less than 155 kilolitres a year a person (from a high of 185 kilolitres a year) by 2012. Figure 5 outlines che achievement of this target by the community through che adoption of a range of water conservation measures, including the two-day a week sprinkler roster system.

Plans will be prioritised by risk and need and not necessarily developed in hierarchical order. This approach recognises the need for plans to be developed at all levels where there is greatest pressure.

State Water Plan 2007, Regional Water Plans and St rategic Water Issue Plans are strategic in nature. They are intended to be informative and will seek to opti mise all aspects of che water cycle. Strategic water plans will be informed by plans p repared by water users (such as for mining or public water supply) and natural resource management groups.

78 AUGUST 2007

Water

Statutory Water Management

Plans

Drinking Water Source Protection Plans

Figure 4. Water planning framework.

Journal of the Australian Water Association

Drainage Plans

Floodplain Management

Plans


technical features

Now rhar rh is rarger has been achieved, Government h as reviewed water efficiency opportunities and ser new rargers fo r each sector (Figure 6). Importantly, rhe Scare Govern ment is seeking ro conserve water in all areas of Western Australia, nor just in Perch.

250

200

~

f.

The Stare W a ter Srraregy ser a target to recycle 20% of all wasrewarer by 2012 . Progress on this rarger is bein g made wirh coral wasrewa cer recycling now over 13%.

100

so

T h is rarger is being retained and strengthen ed. T he lo ng-term goal is fo r wascewarer recycl ing in Western Aus tralia ro exceed 30% . A Scace W ater Recycl in g and C onservation Strategy w ill be d evelo ped to e ngage wit h che communi ty ro exp lo re o p t ions to ach ieve these cargers.

1941 1945 1949 1953 1957 1961 1965 1969 1973 1977 198 1 1985 1989 1993 1997 2001 2005

Figure 5. Perth' s water co nsum ptio n. Water Conservation

Priority Actio n 2007 - 20 I I

Agnculture

20% improvement in water use efficiency 20% improvement in water use efficiency

Minerals and energy Commerce and industry Household use - Perth Household use - regional areas Public open space

Priority Actions 2007-2011 State Water Plan 2007 o utlines priority actions fo r imp lementation that align ro the o bjectives and current focus of water resou rce management in Western Australia (T able 3) . These actions wi ll be progressively d elivered over fi ve years by n ine lead Government agencies . State Water Plan 2007 co n tains more informatio n on these priorit ies . Government will coordinate che imp lementat io n of State Water Plan 2007 and p ublicly repo rt on p rogress. Signifi cant resources h ave been committed co fu nd ongoing improvements in water resource managemen t in Western Australia.

150

Review

Less than I00 kilolitres a person a year ReVJew Review

Water Recycling

Priority Action 2007 - 20 I I

By 20I2

20% wastewater recyding 30% wastewater recycling

Long-term

Figure 6. Targets fo r water conservation and recycling.

Legislative Program The W estern Australian D ep art ment of Water is spearheading a program co modernise and consolid ate water resource managemen t and water services legislatio n. This wide-ranging reform p rogram is

critical co fu lly realise rhe vision of chis Plan, and support decisions o n W ater Reform. In addi tion ro actions listed , che review and reform of water statu tes is a signi fica nt priority for Governmen t.

Ongoing Need and Opportunities for Community Involvement Table 3. Priority Actions 2007-20 11 . 1 Use and recycle water wisely

Conservation and efficiency Recycli ng

2 Pla n and manage water resources susta inably

Regional water plans Statutory water management plans Integrated land and water planning Pricing and cost recovery

3 Invest in science, innovation and education

Groundwater investigation Adapting to climate change Information sha ring and capacity building

4 Protect ecosystems, water qua lity and resources

Catchment protection a nd restoration Dra inage plans Floodplain management pla ns Groundwater dependent ecosystems

5 Enhance

the security of water for the environment

and use

Entitlements and reg istration Trading Metering

6 Develop water resources for a vibrant economy

Source development Sustainability assessment

7 Deliver services for strong and healthy communities

Safe drinking water Service delivery

Regional and ocher water planning will fac ilitate community engagement o n the water cycle and local actions co implement

State Water Plan 2001. T here is an ongoing need for con tin ued investment in public educatio n and collaboration with users, local commu nities and natural resource managemen t groups.

The Authors Meredith Blais and Helen Forte were seconded co the D epartment of the Premier and Cabinet from rhe Water Corporation and Department of W ater respectively, co develop State Water Plan 2001. Mered ith is on rhe AWA WA Branch Committee and H elen is an AW A member. Email: m blais@dpc.wa.gov.au

For more information on water resource management in Western Australia, or to download a copy of State Water Plan 2 007, visit www.water.wa.gov.au.

Journa l of the Australian Water Association

Water

AUGUST 20 07 79


PUTTING A LI D ON EVAPORATION Ballarac company, C.E. Barclerr, has been purring a lid on evaporation with the EVap Cap â&#x201E;˘. F ro m vineyards to walnut crops, fa rmers are relyi ng on th e E-VapCap to elimi nate evap oration and improve water quality. O nly recencly, Des Wood, a farmer at Donald, Victoria, received funding to install the lid on a storage dam on his property. E-VapCap is a p atented floating cover of light impervious, UV treated polyethylene. A black b ubble underside enables flotatio n while preventing evaporation, while the white UV stabilised top side, deflects the sun. Su itable for any water storage configu ration ,

E-VapCaps are installed at dam and reservo ir locations across the country. Benefits of the E-VapCap also include reduction of sale build up, reductio n in algal growth, reduction in bank erosio n and imp roved water quality. E-VapCap's are prefabricated and sections are installed using a unique 'on the water' welding process that allows fo r the covers to be tailored to shape and placed on fu ll dams.

Water Business aims to keep readers alert to business news and new p roduct releases within the water sector. Media releases should be email ed to Brian Raulc at brian.rault@halledic.com.au or Tel (03) 8534 501 4. AWA wishes co advise readers that Water Business information is supplied by third parties and as such, AWA is nor responsible fo r the accuracy , or oth erwise, of the information submitted. Des Wood states chat "since installing our Bartlett Evap Cap dam cover in 2006 on o ur 40 megalitre dam, we estimate chat we have saved over 8 megalitres of water!" Des also po ints out that ' the p roduce has endured severe weather extremes including high winds, incense heat and frosts, yet the water q uality remains a h igh standard, "giving us clear, algae free water". Another customer explains th at in n ine mon ths since installation, "we believe we have eliminated evaporation fro m the d am losing o n ly 60 0mm from the 20% o f the dam we chose to have uncovered . D u ring che same period , neigh bouring dams lose about 2.0 metres."

Cali Bartlett today to arrange a quote for an E- VapCap or inquire about their dam liners, Tel 1800 63 99 66.

ROCI MONITORS LONE WORKER SAFETY Other covers need to be installed when dams are em pty. The E-VapCap cover can bes installed when the dam is at capacity ensuring a benefit from day one.

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Call In, ROCI, was developed by Sage Technology specifically for organisarions with employees workin g alone or in remote areas. ROCI addresses the occup ational health and safery concerns associated with monitoring the safery and well-being of chose workers. le elim inates the need for repeated calls to mobile p hones to check on people working alone. Instead , lone workers are issued wirh GPSenab led PDA phones run ning Windows Mobile 5.0 . They log in at the scare of their sh ift and are then remin ded, via visual and aud ible alerts, of approaching check-in times at p redetermined intervals throughout their work day. Checking in is as simple as tapping the PDA screen with a fi nger or stylus, so there is minimal interruption to the worker. ROCI's monitori ng featu re automatically alerts no minated personnel when a check in is missed while the inbuilt GPS p in points the worker's location to within five metres. ROCI provides all the necessary infor mation to follow up on m issed checkins and locate the remote worker. A key benefit of ROCI is chat ir delivers passive management of a critical OHS issue. Boch employers and employees enjoy peace of mi nd knowing chat monitoring is caking place and chat action is only required if a check-in is missed.

Employers are also able to divert staff from making monitoring phone calls to u ndertake other duties. ROCI is suited to any industry with remo te o r lone workers including water authorities. Water authorities, for example, may have employees working alone o r remotely on a range of inspection, maintenance and metering casks, and even gardeners .

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80 AUGUST 2007

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