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Volume 37 No 1

FEBRUARY 2010

AWA JOURNAL OF THE AUSTRALIAN WATER ASSOCIATION


Water loss is a US$14 billion problem.

WaterGEMSÂŽ - de livers active le akag e cont rol , press ure man agement strategies an d imp roves the sp eed and qual ity of re pairs. HAMMERÂŽ - reduces breakages ca used by high pressure t ran sients. BentleyÂŽ Water - identifie s aging infrastructu re and enables remedi ation pl anning strateg ies.


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Journal of the Aust,al;an Wale, Assoc;auon ISSN 0310-0367

Volume 37 No 1 February 2010

contents REGULAR FEATURES From the AWA President

Flexibility for Sustainability

PRobinson

4

From the AWA Chief Executive Another Federal Intervention? T Mollenkopf 5 My Point of View EUnderwood 6 Crosscurrent 10 Aquaphemera RKnee 10 Industry News

Cream of the Crop Recognised at the Victorian Water Awards - see page 20

16

AWA News

19

Events Calendar

38

Conference Reports

41

FEATURE REPORTS Accounting for Australia's Water MSmith, Chair of the Water Accounting Standards Board

44

Water Quality Research Australia (WQRA): Our First Year A Gackle, DHalliwell, J Dawe

48 Recognising Excellence in the Australian Water Industry see page 30

AWA CONTACT DETAILS Australian Water Association ABN 78 096 035 773 Level 6, 655 Pacific Hwy, PO Box 222, St Leonards NSW 1590 Tel: +61 2 9436 0055 Fax: +61 2 9436 0155 Email: info@awa.asn.au Web: www.awa.asn.au DISCLAIMER Australian Water Association assumes no responsibility for opinion or statements of facts expressed by contributors or advertisers. COPYRIGHT AWA Water Journal is subject to copyright and may not be reproduced in any format without written permission of the AWA. To seek permission to reproduce Water Journal materials, send your request to media@awa.asn.au WATER JOURNAL MISSION STATEMENT 'To provide a journal that interests and informs on water matters, Australian and international, covering technological, environmental, economic and social aspects, and to provide a repository of useful refereed papers. ' PUBLISH DATES Water Journal is published eight times per year: February, April, May, June, August, September, November and December. EDITORIAL BOARD Chair: Frank RBishop; Or Bruce Anderson, AECOM; Dr Terry Anderson, Consultant SEWL; Michael Chapman, GHD; Robert Ford, Central Highlands Water (rtd); Anthony Gibson, Ecowise; Dr Brian Labza, Vic Health; Dr Robbert van Oorschot, GHD; John Poon, CH2M Hill; David Power, BECA Consultants; Professor Felicity Roddick, RMIT University; Dr Ashok Sharma, CSIRO; and EA (Bob) Swinton, Technical Editor.

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EDITORIAL SUBMISSIONS Water Journal welcomes editorial submissions for technical and topical articles, news, opinion pieces, business

information and letters to the editor. Acceptance of editorial submissions is at the discretion of the editor and editorial board. • Technical Papers and Features Bob Swinton, Technical Editor, Water Journal- bswinton@bigpond.net.au AND journal@awa.asn.au Papers 3,000-4,000 words and graphics; or topical articles of up to 2,000 words relating to all areas of the water cycle and water business. Submissions are tabled at monthly editorial board meetings and where appropriate are assigned referees. Referee comments will be forwarded to the principal author for further action. Authors should be mindful that Water Journal is published in a 3 column 'magazine' format rather than the full-page format of Word documents. Graphics should be set up so that they will still be clearly legible when reduced to two-column size (about 12cm wide). Tables and figures need to be numbered with the appropriate reference in the text e.g. see Figure 1, not just placed in the text with a (see below) reference as they may end up anywhere on the page when typeset. • Industry News, Opinion pieces and Media Releases Helen Kelton, Editor, Water Journal- journal@awa.asn.au • Water Business and Product News Brian Raul!, National Sales and Advertising Manager, Hallmark Editions - brian.rault@halledit.com.au

ADVERTISING Advertisements are included as an information service to readers and are reviewed before publication to ensure relevance to the water sector and objectives of the AWA. Brian Raul!, National Sales and Advertising Manager, Hallmark Editions - brian.rault@halledit.com.au Tel: +61 3 8534 5014 AWA BOOKSHOP Copies of Water Journal, including back issues, are available from the AWA Bookshop for $12.50 plus postage and handling. Email: bookshop@awa.asn.au PUBLISHER Hallmark Editions, PO Box 84, Hampton, Vic 3188 Tel: 61 3 8534 5000 Fax: 61 3 9530 8911 Email: hallmark.editions@halledit.com.au

OUR COVER Ms Tanya Doody, a CSIRO Spatial and Forest Eco-hydrologist, took this photo of the sunset over the Murray River at Murtha Floodplain near Renmark (SA). To help manage Australia's precious rivers and water resources, CSIRO' s Water for a Healthy Country Flagship and the Bureau of Meteorology are together developing technology to provide up-to-date and ongoing assessments of the past, present and possible future water balance. See page 110.

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FEBRUARY 2010 1


water

Reducing Water Use for Industrial and Commercial Cleaning - see page 92

Monitoring Australia's Water Resources - see page 11 O

Catchment Knowledge - the Underrated Barrier to Waterborne Disease - see page 132

TECHNICAL FEATURES ( [B] INDICATES THE PAPER HAS BEEN REFEREED) WATER RECYCLING & REUSE

[ii

Quantifying Pathogen Log Reduction in Australian Activated Sludge Plants T G Flapper, B Campbell, D Deere, J Blackbeard, D Halliwell

For recycling purposes a log reduction of 1 to 3 can be attributed

56

[I]

Efficiency of RO for Removal of Chemical Contaminants Results from a two year monitoring program in Perth, WA

C Rodriguez, R Lugg, P Van Buynder, B Devine, A Cook, P Weinstein

64

[II] Effective Removal of Pathogens and Micropollutants by Ozone and GAC An alternative to membrane processes J Reungoat, M Macova, S Carswell, B I Escher, J F Mueller, W Gernjak, J Keller

69

WATER EFFICIENCY

[ii What's the Return on a Rebate? Incentives via a points system

[I]

GWatkins

76

A Turner, J Fyfe, M Retamal, S White, A Coates

82

A Jones

92

P Holt, D Lee, M Ferguson, M Dawson, GWalgenwitz

101

A van Dijk, R Lemon

110

J Stanmore, R lyadurai

118

R Ford

128

R Considine, R Ford

130

C Ferguson, D Sheehan

132

SEQ's One To One Water Savings Program

Unpacking residential high water usage

Reducing Water Use for Industrial and Commercial Cleaning Both technology and psychology are needed ENERGY EFFICIENCY

[i] Sydney's Water and Energy Efficiency Balance A combined view to ensure energy and water efficiencies are optimised CLIMATE CHANGE IMPACTS

Monitoring Australia's Water Resources New observation system to assess water availability and use

[I] Quantifying Climate Change Impacts on the Urban Water Cycle Not only on water availability, but also the performance of urban water systems WATER SOURCE PROTECTION FEATURE

Catchment Management for Drinking Water Protection Risk Management of Catchments for Drinking Water Catchment Knowledge - the Underrated Barrier to Waterborne Disease 2 FEBRUARY 201 0 water


Journal of the Australian Water Association ISSN 0310-0367 Volume 37 No 1 February 201 O

contents

Development Control Within Catchments - see page 139

Black Saturday in Melbourne's Catchments - see page 144

Finding a Water Balance for Cotton Production - see page 164

TECHNICAL FEATURES( [~] INDICATES THE PAPER HAS BEEN REFEREED) WATER SOURCE PROTECTION FEATURE - continued

Tools and Resources for Catchment and Groundwater Management Strategic Land Use Planning Development Control Within Catchments Possible Changes to the ADWG: Quantifying the Risks

P Feehan, A Brinkley

134

RFord, NLewis

137

A Hurlimann, R Ford

139

R Ford, D Cunliffe

142

T Conway, K Miller

144

K Hellier, M Stevens

149

N Schofield

153

R Dexter, C Chow

158

A Kay

164

M Griffith, S Biddulph

166

S Shmia, N Bradley

173

Water Source Protection: Incident Management

Black Saturday in Melbourne's Catchments

The 2007 Storm Impacts On Melbourne's Unfiltered Water Supply RIVER HEALTH

Australia Wide Assessment of River Health A remarkably rapid paradigm shift

[i] Real Time Monitoring of Water Quality in Rivers New technology now proving itself for all forms of water quality management

Finding a Water Balance for Cotton Production The national debate needs balance and factual evidence Replacement of Environmental Flows in the Hawkesbury-Nepean River Assessing the influence of low conductivity recycled water on freshwater aquatic biota WATER QUALITY

[i] Microwave-Powered UV Disinfection Receives Validation for 'Crypto' Successfully validated against MS2 bacteriophage WATER BUSINESS

New Products and Business Information. Special feature: Pipelines

177

Advertisers' Index

200

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FEBRUARY 2010 3


from the president

Flexibility for Sustainability Peter Robinson AWA President

Welcome to 2010. I trust everyone had a refreshing break over the festive season as we all look forward to continuing challenges in the Australian Water Sector for 2010. As I mentioned in the final edition of Water for 2009, our industry, and specifically our Assoc iation, has enjoyed a period of strong growth and unprecedented interest over the recent past. It is incumbent upon us all to maintain this community involvement and levels of interest going forward. One area of opportunity, or challenge, depending on which side of the optimist or pessimist coin you are, is the broad field of alternative water sources for sustainable cities. Evidence exists from recent and cu rrent projects of the gradual removal of demarcation between urban and rural water supplies. A more holistic approach to the management of the total water cycle will be required for a sustainable future, particularly for us here in 'water constrained' Australia. This issue does face significant emotional and political considerations. In some cases the exchange of water from historical markets, such as the rural irrigation sector into new markets, such as a growing urban demand , requires the unraveling of decades worth of commitments, cultures and methods. Current considerations of alternative sources for sustainable cities have gone well beyond the 'water sensitive urban design' benefits that have become part and parcel of 'sensible' urban development design practices. These considerations include stormwater harvesting, recycling, groundwater sources, aquifer storage and recovery and desalination. The trick for governments, both State and Federal, will be to get the balance of these alternative sources right for sustainable long term solutions. Currently, the five largest capital cities in Australia have built (or are building) major desalination plants. This is understandable - it is simply not acceptable to have our cities run out of wat er and desalination provides a rainfall independent supply. Further, the intensity and length of drought has forced immediate actions to ensure security of supply. Under these tight timeframes and community pressures for action, major investment decisions have been required.

4 FEBRUARY 2010 water

Having made an extensive capital investment into one or two alternative water sources to ensure security of supply, it is unlikely that similar levels of investment, at least in the short term, can be expected in other alternative supply areas. Unless we are carefu l this could impact the take up rate, or expansion of these other sources such as recycled water in urban centres. We have bought ourselves some time. We should use this to continue to build our portfolio of water resources and demand management approaches for the next decades. The communit y looks to us, as an industry, t o make sure we inform, influence and direct where the future alternative water sources come from in a sustainable way. "Flexibility for Sustainability" means, as our population grows and demand for water increases, particularly for cities, we won't rely on one or two sources for water. It wi ll be a balanced suite of alternative sources. This will take time to debate and deliver before we achieve a truly integrated sustainable water cycle. Enjoy 2010.


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feature article

Accounting for Australia's Water By Mike Smith, Chair of the Water Accounting Standards Board What is Water Accounting? Water accounting is a systematic process of identifying, recognising, quantifying, reporting , and assuring information about water, the rights or other claims to that water, and the obligations against that water. Through the National Water Initiative (NWI), Australian federal and state and territory governments have committed to the achievement of a national water accounting process which is able to 'meet the information needs of different water systems in respect to planning, monitoring, trading, environmental management and on-farm management'. This commitment is being actioned through the development and implementation of:

THE WATER ACCOUNTING STANDARDS BOARD The Water Accounting Standards Board (WASS) has been established by the Bureau of Meteorology as an independent expert advisory board. The initial WASS members, who will continue until the end of 2010, have been drawn from the membership of the Water Accounting Development Committee to ensure continuity of the National Water Accounting Development project commenced in 2007. The WASS members bring to the board wide ranging expertise covering both accounting and water resource management disciplines.

• water accounting system standards

Chairman

• standardised water reporting formats

The WASS is chaired by Mike Smith who is currently the Director State and National Water Programs for the Department of Water, Land and Biodiversity Conservation in South Australia. Mike is a Civil Engineer and has had 27 years of experience in water resources management.

• water resources accounts that can be reconciled and • aggregated to produce a national water account. The outcome of water accounting under the NWI is 'to ensure that adequate measurement, monitoring and reporting systems are in place in all jurisdictions, to support public and investor confidence in the amount of water being traded, extracted for consumptive use, and recovered and managed for environmental and other public benefit outcomes.' A national approach to water accounting encompasses: • the user requirements of water accounting • institutional arrangements for the development and issuing of water accounting standards and guidelines • the conceptual framework and procedures underpinning the development of water accounting standards and guidelines • the water accounting standards and guidelines that inform the preparation and presentation of water accounting reports • the water accounting information systems and data sources from which water accounting reports derive • the assurance processes that attest to the integrity of the information systems and the level of compliance of reports with standards (Figure 1).

Members W Peter Day is currently chairman and non-executive director of a number of companies. Peter is a former Chairman of the Australian Accounting Standards Board, has worked in International Accounting Standard setting and served as Deputy Chairman of the Australian Securities and Investments Commission. Denis Flett is a civil engineer and currently a director of DG Consulting. Denis has had wide ranging water resource operations and management experience including as the foundation CEO of Goulburn-Murray Water and Chair of the Independent Audit Group for the Murray-Darling Basin Authority. Professor Jayne Godfrey is Professor of Financial Accounting and President of the Academic Board of Monash University. She has served on the Australian Accounting Standards Board, been a Director of a State Borrowing Authority, CPA Australia Divisional President and President of the Accounting Association of Australia and New Zealand. Tom Vanderbyl is a civil engineer and currently the Manager, Corporate Strategy for SunWater. Over the past 15 years, Tom has taken a leading role within Queensland in the planning and delivery of water reforms relating to the sustainable allocation of water, the establishment of tradeable water entitlements and the provision of water for the environment. Contact The Water Accounting Standards Board is supported by a small team located within the Bureau of Meteorology. Volker Aeuckens is the WASS Executive Officer and can be contacted at v.aeuckens@bom.gov.au or telephone (02) 6232 3519.

Figure 1. Key elements of a national approach to water accounting.

44 FEBRUARY 2010 water

feature articles


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In2025, two-thirds of the planet Will not have drinking water, are we going to wash our hands of it all?

Be_ 1s an attitude. A can t.o action in order t.o start up the thousands of ecttonsweilOed t.oC&Tyouttogetbe,..AD4--todo1t;-.

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feature article Why Do We Need Water Accounting? In 2008-09, 1.5 million megalitres of water entitlements and 2.2 million megalitres of allocations were traded throughout Australia at a cumulative market value of $2.8 billion. Systems are in place to account for the volume and value of water being traded, but they have been developed in an ad hoc and inconsistent fashion across the country, leading to divergent outputs and understandings. As the competition for water resources increases, it is more important than ever to account, fully and consist ently, for how water is shared between the economy, critical human needs and the environment.

Who Benefits from Water Accounting? Water accounting facilitates informed decision-making based upon information about water resources. Similar to the way general purpose financial reports assist financial and business decision-making, General Purpose Water Accounting Reports (GPWAR) will assist their users to make and evaluate decisions about the allocation of resources. These reports wi ll usually be prepared by those with a water management responsibility and wi ll address the general information needs of people -water users, water market investors, traders and brokers, environmental organisations, auditors, financiers, local governments, researchers, planners and policy formulators-who cannot normally command this information directly from the organisations that hold it. General Purpose Water Accounting Reports and the National Water Account are designed to: • provide information that is relevant, reliable, comparable and understandable • inform their users about how water resources have been sourced, managed, shared and utilised during the reporting period • enhance their users' confidence in their water-related investment decisions (Figure 2).

Developing the Foundations of Water Accounting Australian governments have been involved in the project t hrough a Jurisdictional Reference Panel and the hosting of pilot projects to test water accounti ng concepts and standards through demonstration water accounts. Under the Commonwealth Water Act (2007), the Bureau of Meteorology has three specific responsibilities with respect to water accounting: • the issuing of water accounting standards • compiling and maintaining water accounts for Australia, including a set of water accounts to be known as the Nat ional Water Account

ensure they remain cohesive and integrated . However, preparers of reports can draw on the WACF for principle-based guidance in the production of a GPWAR. The WACF comprises eight Statements of Water Accounting Concepts and has been written in consultation with water industry experts, financial accountants and financial accounting standard setters. The WACF is now available for public comment. Feedback will be t aken into account when the WACF is formally reviewed following publication of the first National Water Accou nt at the end of 2010. This document can be downloaded at: http://www .bom.gov.au/water/wasb/wacf-download.php, and feedback can be emailed to wasbofeedback@bom.gov.au.

Preliminary Australian Water Accounting Standard (PAWAS) The PAWAS is a preliminary version of the Australian Water Accounting Standards (AWAS) prepared specifically to guide the Pilot for the National Water Account released in December 2009. The PAWAS has been available for public comment since July 2009. Feedback on the practical application of the PAWAS wi ll inform the development of the AWAS. The PAWAS was also tested more broadly to identify issues that need to be addressed in future AWAS by: • Harvey Water in Western Australia • Hydro Tasmania • Northern Territory Power and Water • the Minerals Council of Australia • AMCOR. An exposure draft of the AWAS is scheduled for release in June 2010. This will be used for preparation and presentation of the National Wat er Account. At the broader level, wat er entities are encouraged to prepare GPWAR using the exposure draft of the AWAS on a voluntary basis. Significant further testing (including a cost benefit analysis) of the AWAS Exposure Draft and its successor, the AWAS, will occur in the f uture. The decision on whether adoption of the AWAS wi ll ever be made mandatory is one for the Bureau of Meteorology and the Australian Government to make once the AWAS has evolved to a suitable level. The PAWAS can be downloaded at: http://www.bom.gov.au/water/wasb/pawas-download.php, and feedback can be emailed to wasbofeedback@bom.gov.au Further information on the development of water accounting in Australia, can be obtained at www.bom.gov.au/water!wasb

•...-

- il

• publishing annually the National Water Account in a form readily accessible by the public. The Water Accounting Standards Board (WASB) has been established as an independent expert advisory board to the Bureau to oversee and coordinate all Australian Water Accounting Standards development activities.

Water Accounting Conceptual Framework The theoretical foundation of water accounti ng is contained in the Water Accounting Conceptual Framework for the Preparation and Presentation of General Purpose Water Accounting Reports (WACF). The primary purpose of t he WACF is to guide the development of Australian Water Accounting Standards to

4 6 FEBRUARY 2010

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1

.

Figure 2. Delivery of General Purpose Water Accounting Report to a user.

feature articles


feature article

Water Quality Research Australia ... our first year Angela Gackle, David Halliwell, Jodieann Dawe Water Quality Research Australia (WQRA) was officially launched in August 2008 and has completed its first full year of operation. The formation of WQRA marks the successful transition from a Cooperative Research Centre model (the CRC for Wat er Quality and Treatment) to an indust ry-funded company. Thi s reflective paper outlines the year that was for a relatively new start up company. It is one of the very few examples of a company that has made a successful transition from a Cooperative Research Centre t o a member funded, public company. A key req uirement in being able to make this transition was a clearly articulated scope of operations that fulfils an industry need, as well as significant engagement with the key players with in the Australian water community. The formation and on-going success of WQRA is a tribute to the broad range of stakeholders that share the company's vision as well as a desire to see the water industry grow and prosper. The foc us in 2009 was on laying a solid company foundation to ensure a sustainable and efficient organisation that is able to provide value to its members and the Australian water community. The last 12 months have been a challenging but exciting time as WQRA recruited key staff, developed and implemented the initial research portfolio, and most importantly, engaged with members and key stakeholders to determine the strategic priorities to be addressed both now and in t he years ahead. At the completion of the CRC for Water Quality and Treatment (CRCWQT), WQRA assumed responsibility for overseeing the completion of unfinished CRCWQT projects and there has been a concerted effort to complet e and distribute all outstanding reports to ensure that the wealth of knowledge developed through the CRCWQT is captured and transferred to users. More than 20 reports have been completed and disseminated and can be freely downloaded from the WQRA website: www.wqra.com.au - along with many other CRCWQT publications. Table 1 lists the reports that were released in 2009.

Membership WQRA's membership is its backbone, and two-way engagement with members is critical to the success of the research programs and WQRA. A key focus has been to get to know members and their organisational needs, as well as determining how WQRA can support members through research and related activities. Communication and engagement with members is through many channels including meetings, newsletters, website and company visits. During 2009 the WQRA CEO and Program Managers met with many inspiring and dedicated people comm itted to ensuring water security and the provision of high quality wat er for Australians. In the past year WQRA has been delighted to welcome a number of new members - Cradle Coast Water (Tas), Ben Lomond Water (Tas), Syme and Nancarrow (WA), Murdoch University (WA), Water Futures (NSW) and ChemCentre (WA). This brings the WQRA membership to 43, which encompasses all states of Australia and many different facets of t he Australian

48 FEBRUARY 2010 water

Table 1. CRCWQT reports completed in 2009 - available to download from www.wqra.com.au. RR 49: Small water system reliability in remote Indigenous communities in the Kimberley RR 62:

Causes and prevention of chlorinous off-flavours in potable water

RR 63:

Membrane distillation of brine wastes

RR 66:

Optimisation of Cylindrospermopsin screening assays

RR 67:

A practical guide to reservoir management

RR 68:

Optimising the water treatment and disinfection train for pathogen removal

RR 77:

Benchmarking water sensitive urban design - Payne Road

RR 79: Understanding the growth of opportunistic pathogens within distribution systems

water community. The current WQRA members are listed in Table 2. New membership enquiries are always welcome. There are many benefits of membership, including access to almost $40m of current R&D investment in water quality research projects in Australia and overseas, as well as access to a wide network of academic, government and industry contacts involved with the water industry.

Governance Since its inception, WQRA has had strong governance, through the leadership of its Board of Directors. The WQRA Board comprises industry, regulatory and academic representatives elected by the members. To ensure corporate knowledge is retained, the Board has a staggered membership, with half of the positions vacated each year. At the recent AGM in November 2009 two incumbent Board Directors were re-elected and two new Directors were appointed. The current Board Directors are: Prof Michael R Moore - Independent Chair Ms Jan Bowman (DoH, Vic) - Industry Represent ative (reelected 2008) Dr Dharma Dharmabalan (Caliban Water) - Industry Representative (re-elected 2008) Ms Anne Howe (SA Water) - Industry Representative (re-elected 2008) Dr John Howard (AWQC) - Research Representative (re-elected 2009) Prof Simon Beecham (UniSA) - Research Representative (new director) Prof David Waite (UNSW) - Research Represent ative (new director) Mr Keith Cadee (Water Corporation) - Industry Representative (re-elected 2009) Ms Jodieann Dawe (WQRA) - WQRA CEO The Board is supported by the Company Secretary Mr Phillip Auckland (WQRA) and Ms Susan Spragg, EA to the CEO. WQRA wou ld also like to especially thank the two outgoing Direct ors - Professors Chris Davis (UTS) and J ohn McNeil (Monash University) - for all their hard work and enthusiasm

feature articles


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feature article Table 2. WQRA Member organisations. Industry Members

South Australian Water Corporation

Murdoch University

Australian Water Association ltd

South East Water Limited

RMIT University

Degremont Pty ltd

Sydney Catchment Authority

University of Adelaide

Barwon Region Water Corporation

United Water International Pty ltd

University of NSW

Ben Lomond Water Central Gippsland Regional Water Corporation

Wannon Region Water Corporation

University of Queensland

Water Corporation of WA

University of South Australia

Central Highlands Water

Yarra Valley Water Ltd

University of Technology, Sydney

City West Water ltd Caliban Region Water Corporation

University of Wollongong

Research Members

Victoria University

Cradle Mountain Water

Australian Water Quality Centre

Department of Health (Vic)

Centre for Appropriate Technology

Grampians Wimmera Mallee Water Corporation

ChemCentre

Department of Water (WA)

Goulburn Valley Regional Water Corporation

Curtin University of Technology

Lower Murray Urban and Rural Water Corporation

Hunter Water Corporation

Flinders University

NSW Department of Health

Melbourne Water Corporation

Griffith University

Syme & Nancarrow Water

Power & Water Corporation

Monash University

Water Future

during their two year tenure on the WQRA Board, particularly in providing valuable advice and guidance in developing the WQRA strategy. The WQRA Board is supported by a Scientific Board Advisory Committee and a Regulatory Board Advisory Committee, which provide insightful and strategic advice and direction to the research priorities. In addition, to the Board and the Board Advisory Committees, WQRA has two management committees - the Project Review Team and the Education Committee - which provide invaluable support to WQRA in its operations and include representatives from industry and research organisations. One of the key objectives of the Board has been to determine the ongoing strategic direction of WQRA. Through a series of workshops and an extensive consultative process, WQRA has been able to determine its focus for the coming years.

Research Programs WQRA's research portfolio is fundamental to the company's success and is structured around 3 programs - Drinking Water,

General Members

Recycled Water and Wastewater Research. Refining the immediate and emerging research issues for the Australian water community has been a priority over the last 12 months to ensure that members' funds are invested judiciously. Identification of high level research issues and priorities was achieved through workshops in late 2008, which were attended by a wide cross- section of WQRA membership and invited stakeholders. The workshops were followed by a call for project concepts and the final short list of project concepts was determined by a two-stage member voting process. Throughout the development of the initial research portfolio, both the engagement of members and the integrity and transparency of the selection process has been critical. Projects are either wholly funded by WQRA or funded in partnership with key stakeholders. During 2009 funding

Vision The trusted provider of scientific evidence needed to ensure safe water for Australians

Mission

To lead and facilitate high quality and collaborative research of national significance and to promote implementation of research outcomes to address current and emerging public health issues in water quality Strategic Aims - 2009-201 0 1. Develop the research strategic plan to address water quality issues of national significance 2. Collaborate with all key stakeholders to deliver the research plan 3. Provide scientific evidence to underpin the rolling review of guidelines relating to safe drinking water and recycled water 4. Facilitate knowledge transfer and uptake of research outcomes to mitigate risk 5. Promote importance of safe water on the national agenda

Some of the initial WQRA Directors.

50 FEBRUARY 201 0

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6. Build capacity and capability for high quality research to support the Australian Water community.

feature articles


feature article success was achieved with a number of col laborators, including the NHMRC, Australian Research Council , the Victorian Smart Water Fund, the National Water Commission, the Water Research Foundation (US) and numerous Australian water authorities. A highlight of the year was the successful application by Monash University, with WQRA as the industry partner, for funding under the inaugural NHMRC ' Partnerships for Better Health' initiative.

2010 Summer Students at the Orientation Day in Adelaide with Carolyn Bellamy (far right) Coordinator of the Education Program.

A significant benefit of the philosophy and research approach adopted by WQRA is th e significant leverage of member funds achieved. For example, at the end of 2009, WQRA achieved approximately $4 of external cash funding for every WQRA $1 invested, and approximately double this fundi ng ratio, when in-kind funding is included.

Building Future Capability WQRA has acknowledged the success of the former CRCWQT Education Program, through the contin uation and ext ension of this Program. The prime objective of the Program, through the various initiatives offered, is to build future capability and capacity for the Australian water industry. Selecting, nurturing and encouraging high quality students to pursue careers in

A

water-related research areas is critical as the industry faces looming staff and skills shortage. Targeted at undergraduate researchers, the second successful Summer Scholarships reporting seminar was held in Melbourne, Feb 2009, with 10 students presenting on a wide range of indust ry related research topics. In November 2009, nine new Summer Research students commenced their projects and attended an orientation day. The students subsequently had the opportunity to meet a range of WQRA member representatives and other leaders in the water commun ity. The reporting seminar is an integral component of the WQRA Members Meeting, scheduled for the end of February 201 0 in Sydney.

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feature article water and in recycled/wastewater, lagoon treatment systems and decentralised systems.

Two new PhD students have commenced under the WQRA PhD Initiative with two more commencing in 2010. WQRA's first two Honours students will also be starting this year.

WQRA is committed to supporting and attending the annual AWA Ozwater conference, the most significant and welltargeted event on the Australian water industry calendar. At Ozwater '10 WQRA will once again have a stand at the trade exhibition, and is also running a workshop "Determining the Water Quality Research Agenda - Perspectives from the Australian Water Community". During this session a panel will explore the perspectives of different stakeholders and debate R&D priorities in the face of significant changes facing management of water supplies.

In t he coming years, WQRA aims to bu ild the various initiatives for the Education Program so that it continues to provide high q uality, motivated and trained researchers to t he water industry and greater opportunity for industry members to become more involved with t he Program. Details about WQRA's Education Program initiatives can be found on t he 'Education ' page of the website.

Workshops and Conferences

The Future

WQRA has supported t he development of the wat er industry and transfer of research outcomes through targeted sponsorship of conferences and by conven ing workshops that bring together researchers from around t he country with interest in specific topical areas.

WQRA has achieved a significant amount in t he short time since its incept ion. This paper has highlighted some of the key areas of progress over t he past year. Having complet ed many of the essential tasks requi red to initiate a start up, WQRA is evolving into a more st rat egic and focused company wh ich values the influential relationships t hat have been - and contin ue to be - formed both nationally and internat ionally. WQRA is committed to continuing the catalytic role it is perform ing in t he water quality and health space for the Australian water community.

Outcomes from involvement in these act ivities include identification of research gaps that may subsequently be developed into funded WQRA project s, t he establishment of new collaborations or interest groups to develop ideas further or alternatively, the further disseminat ion and applicat ion of existing information for industry benefit. Many of the presentations and documents resulting from these activities can be viewed on t he WQRA website in the 'Conferences and Workshops' area www .wq ra. com. au/ conferences. ht m.

Researc h outcomes are now starting to flow from WQ RA projects for the benefit of its members and the wider indust ry, as well as Australian consumers, and these benefits are expect ed to grow as more momentum is generated in the year ahead.

Since its inception, WQRA has convened workshops for its members and other invited stakeholders on t he following topics, including research issues and priorities in drinking

For more information about WQRA go to www.wqra.com.au

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PUMP & PIPING TRAINING PUMP FUNDAMENTALS Seminar Objectives

DAY1

DAY2

At the completion of this seminar, each delegate should be able to:

BACKGROUND INFORMATION Terms and Definitions Fluid Properties Basic Hydraulics Theory and Calculations Cavitation Friction Losses in Pipes and Fittings Pump Classification and Examples Pump Selection Guidelines

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

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

Delegate Pre-Requisites

CENTRIFUGAL PUMPS Components, Types and Examples Affinity Laws and Characteristic Curves Matching the System to the Pump System Curve Calculations Viscosity Effects Parallel and Series Pumping Troubleshooting

SEALS AND PACKING General Overview Components and Types Applications and Selection Installation, Maintenance, Troubleshooting PUMP DRIVES General Overview Canned and Magnetic Setups Belts, Gearboxes, Mechanical Va riators Electric Motors and Inverters Other Drive Types

INTRODUCTION TO CENTRIFUGAL SLURRY PUMPS Slurry Classifications and Rheology Slurry Characteristics Solids Content and Settling Velocities Typical Components and Assemblies Characteristics Curves Selection Criteria

It is a requirement that each delegate has an understand i ng of mechanical POSITIVE DISPLACEMENT (PD) PUMPS components. A basic understanding (trade PD Pump Theory level) engineering maths would also be Typical System Curves advantageous. Comparison to Centrifugal Pumps

Who Should Attend?

EDUCTORS (JET PUMPS) Principle of Operation Applications

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

Seminar Materials

This seminar has been designed for:

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

Pump Fundamentals Seminar

Liquid Piping Fundamentals Seminar

Adelaide

Adelaide

10 & 11 May 2010

Perth

17 & 18 May 2010

Perth

19 & 20 May 2010

Brisbane

26 & 27 May 2010

Rydges Hotel, Perth

Rydges Hotel, Perth

Brisbane

24 & 25 May 2010

The Chifley at Lennons, Brisbane

The Chifley at Lennons, Brisbane

Melbourne

1 & 2 June 2010 The Vibe Savoy Hotel, Melbourne

12 & 13 May 2010 The Chifley on South Terrace, Adelaide

The Chifley on South Terrace, Adelaide

Melbourne

3 & 4 June 2010 The Vibe Savoy Hotel, Melbourne


DAY 1

DAY2

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

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

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

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

SEMINAR FEE: $1,295.00 each (inclusive of GST) 10% discounts apply for (i) Previous KASA seminar attendees, and/or (ii) a multiple seminar registration, and/or (iii) three or more registrations from the one company at the same time , and/or (iv) registration prior to 5:00pm Sydney time on Friday 9 April 2010. The maximum discount claimable shall be limited to 20%. For more information on these two day seminars (including a full seminar synopsis) and to obtain registration forms and conditions, call KASA Redberg on (02) 9868 1111 or email info@kasa.com.au or visit www.kasa.com.au. KASA Redberg Ply Ltd, ABN 35107 585 375, Ph: (02)98681111 , Fax: (02) 8246 6387


G

water recycling & reuse

refereed paper

QUANTIFYING PATHOGEN LOG REDUCTION IN AUSTRALIAN ACTIVATED SLUDGE PLANTS T G Flapper, B Campbell, D Deere, J Blackbeard, D Halliwell Abstract This work describes the prediction of pathogen reduction performance of Australian activated sludge plants (ASPs) and enables the effect of 'upset' plant conditions on pathogen red uction to be integrated into treatment plant management plans and critical control points (CCPs). The project outcomes assist with the implementation of Australian national and state water recycling guidelines, and aim to minimise the costs associated with validation and management of recycled water plants. This will inform regulators as to the scientifically warranted log red uction value (LRV) of protozoa, viruses and bacteria that can be attributed to ASPs. This paper reports on two major project tasks: a literature review on pathogen and indicator reduction by ASPs; and collation and analysis of Australian ASP data sets that report pathogen and indicator reduction. It was found that a pathogen log 10 reduction value of 1.0 to 3.0 can be attributed to the activated sludge process. Further Pilot Plant work investigating the effect of sludge age on LRV will be presented at Ozwater 2010. Keywords Pathogen , activated sludge, indicator organism, log reduction value (LRV)

Introduction The Australian Guidelines for Water Recycling, Phase 1, 2006 (AGWR) require process steps to undertake validation to demonstrate the log 10 reduction value (LRV) that can be attributed to them over a given operating envelope. For activated sludge plants (ASPs) this can be a difficult, cumbersome and expensive task. This project aims to provide scientific evidence to red uce the cost of validation via two major tasks. Firstly, the cond uct of a detailed literature review, and secondly a review of available Australian datasets. The literature review focused on three key areas: • Mechanisms of pathogen reduction and relationships with surrogates and plant operating parameters that may exist • Pathogen reduction across activated sludge processes from national and international studies, as distinct from primary and tertiary treatment processes • Pathogen monitoring approaches for studies of this type, including both the sampling strategies and analytical tech niques (not discussed in this paper). The data survey review was conducted to better understand national data and possible correlations amongst process parameters and effluent quality parameters from fu ll-scale activated sludge plants demonstrating pathogen reduction. A particular focus of the data review was the investigation of correlations between pathogen LRVs and surrogates, and plant

For recycling purposes a log reduction of 1 to 3 can be attributed. 56 FEBRUARY 2010 water

operating parameters. Twelve treatment facilities from across Australia were surveyed t o capture their operating data and pathogen monitoring information. These represented a cross section of activated sl udge plant configurations, operating regimes and climate zones. Their names and details are held in confidence. For one site, a detailed statistical analysis was cond ucted to review possible correlation coefficients between pathogen LRVs and operating parameters.

Literature Review International review

An int ernational literature review was conducted to collate data associated with pathogen reduction from the activated sludge treatment process unit. Protozoa, viruses and bacteria were evaluated, as well as combi ned pathogen reduction studies. The key factors found to influence pathogen reduction within activated sludge treatment processes were reported to be: • Adsorption of pathogenic microorganisms to suspended solids. Adsorption appears to be relatively rapid with the majority of adsorption complete within an hour, although parasite adsorption may increase for several hours. The rat es of adsorption are not dramatically affected by the mixed liquor suspended solids (MLSS) concentrations or the pH ranges that are characteristic of activated sludge plants. However, anaerobic conditions can rapidly reduce adsorption rates, leading to decreased removal rates. It is therefore concluded that adsorption rates should be relatively st able within an activated sludge process under normal operating conditions. Dramatic changes in operation, such as loss of aeration (leading to anaerobic conditions), significant red uctions in MLSS concentrations (i.e. < 1000 mg/L) or significant reductions in hydraulic retention times would be needed to meaningfully impact on pathogen reduction performance. • Predation/loss of infectivity. As hydraulic and sludge retention time increases, predation becomes increasingly important for virus and bacterial removal/i nactivation. Inactivation of parasite eggs/cysts/oocysts does not appear to occur (i.e. eggs/cysts/ oocysts in final effluent did not appear to have altered infectivity), while limited information on predation rates was found. For viruses and bacteria, predation and inactivation rates are expected to be relatively stable, but would be impacted upon by significant changes in microorganism population characteristics in the biomass, or significant reductions in hydraulic retention times. • Efficiency of clarification. Solids removal (with adsorbed pathogens) is the key pathogen reduction step for activated sludge treatment. Therefore, removal rates will be impacted in proportion to any factor that alters the efficiency of clarification. However, since the suspended solids in the c larified effluent is only a small percentage of the suspended solids that are removed through sludge wasting, pathogen

technical tea ures


G

water recycling & reuse Table 1. Literature review reported pathogen log reduction in activated sludge plants. Pathogen/Indicator No. of papers

% Reduction Mean Median

Log Reduction Value No. of papers Mean Median Std. Dev.

Std. Dev.

(Rose, 1996) (Rose, 2004)

1.2

1.2

0.7

(Rose, 1996)) (Rose, 2004) (Ottoson, 2006

2.5

1.9

1.3

F-RNA phage

(Zhang, 2007) (Ottoson, 2006) (Lucena, 2004) (Rose, 2004)

2.3

2.1

0.7

Somatic coliphage

(Rose, 2004) (Zhang, 2007) (Ottoson, 2006) (Lucena, 2004)

1.9

1.6

0.8

(Sedmak, 2005)

2.4

2.4

0.5

(Ottoson, 2006)

2.44

(Rose, 1996) (Rose, 2001) (Zhang, 2007) (Lucena, 2004)

1.9

2

0.2

(Rose, 2004) (Ottoson, 2006) (Lucena, 2004)

2.2

2.2

0.7

(Rose, 2004) (Ottoson, 2006) (Lucena, 2004)

1.7

1.7

0.6

(Rose, 2001) (Rose, 2004) (Chauret, 1999) (Mayer, 1996) (Ottoson, 2006)

2.0

2.0

0.8

(Rose, 2001 ) 1.7 (Rose, 2004) (Chauret, 1999) (Mayer, 1996) (Ottoson, 2006) (Montemayor, 2005)

1.5

0.6

Coliphage

(Rose, 2001) (Omura, 1989)

98.3

Enterovirus

(Rose, 2001)

97 .8

Total enteric virus

(Yanko, 1993) (Aulicino, 1996) (Rolland, 1983)

98.3

90.1

1.8

88.5

7.3

E.coli Faecal coliforms

(Rose, 2001) (Omura, 1989)) (Aulicino, 1996) (Rolland, 1983)

95.5

Entercocci

(Omura, 1989)

97

96.5

3.3

C. pertringens

Giardia

(Rose, 1996) (Robertson, 2000) (Casson, 1990) (Chauret, 1995) (Neto, 2006) (Caccio, 2003) (Reinoso, 2008)

86.6

91

13.7

Cryptosporidium

(Rose, 1996) (Robertson, 2000) (Chauret, 1995) (Neto, 2006) (Reinoso, 2008)

81.4

97.4

27

ref ereed p aper

acknowledged that this variability cou ld reflect changes in virus influent concentrations, rather than plant performance. The literature findings for both the per cent removal and LRV are summarised in Table 1. The literature also supports that activated sludge should read ily achieve a 1.0 t o 1.5 log 10 removal of Giardia. Cryptosporidium may have lower rates of removal , but it is not possible to establish a definitive removal ratio between the two parasites. Cryptosporidium removals range from similar to the Giardia removals, to approximately 50% lower. The data suggests that activated sludge treatment can achieve 0.5 to 1.5 log 10 removal of Cryptosporidium. Individual plants will have higher or lower levels of pathogen removal performance, influenced by factors such as operational control, plant flows and loadings, and the inclusion of primary treatment before the activated sludge process.

Data Review From Australian ASPs Survey data from twelve ASPs

reductions should be relatively insensitive to small changes in clarifier performance. The literature suggests that activated sludge treatment plants should be able to readily achieve 1.0 to 2.0 log 10 reduction of bacteria and viruses. However, not all the studies reported virus removals of 1.0 log 10 and above. Therefore, some mechanism to quantify actual removals at a treatment facility is critical for accurate predictions. It is also critical that a procedure is in place to address periods of potentially poor treatment plant performance. However, it must be

Public water utilities were contacted to complete a data survey form request associated with activated sludge plant s. Data summaries from twelve plants were submitted representing a range of climate conditions (temperate and cool), operat ing configurations (nitrification, full BNR), and upstream process steps (some with coagulation). Data provided was generally statistically summarised and not provided as raw data. Table 2 presents a summary of the LRV data obtained across twelve surveyed facilities. That is, the 50%ile of

Table 2. Summary of average pathogen data across all sites surveyed. Coliforms

E Coli

FRNA

S Phage

C Pert.

Enteric

Reo

Entero

Adeno

Crypto

Giardia

1.44

50%ile

2.28

2.80

3.91

2.93

2.24

1.90

1.60

1.50

1.70

0.90

95%ile

3.19

3.51

6.02

3.23

2.78

1.90

1.60

1.50

1.70

0.99

1.92

Std Dev

0.55

0.52

1.87

0.29

0.61

na

na

na

na

0.06

0.76

Number

7

13

7

11

13

3

2

Coliforms are thermotolerant coliforms. S Phage is somatic phage. Enteric, Rea, Entero, Adena are virus types investigated. Crypto is Cryptosporidium.

58 FEBRUARY 2010 water

technical features


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water recycling & reuse

Cs]

reported average data. Average data reported was used, as this was the most commonly determined statistic across t he dataset. No adjustment has been made for process configu ration. It can be seen that the log reductions vary across the organism, and within the organism, with general ly high standard deviations reported.

°i ~

1

Detailed statistical review of one ASP

_3

0.5

A statist ical review of one AS P was conducted, in wh ich a short term raw data set, including information on the concentrations of various microbial indicator organisms and physico-chemical factors, was examined to identify operational parameters that may be predictive for pathogen removal - i.e. to represent a 'surrogate' . LRVs for t he microbial parameters are shown in Figure 1. The parameters indicate LRVs of 2.50 for bacteria, 2.24 for spore-forming bacteria and protozoa, and 2.76 for viruses. The variation over time was around 0.3 log 10 for viruses and spore-forming bacteria and protozoa, and around 0.2 log 10 for bacteria. Despite the small data set, significant correlations were observed between the following microbial and physico-chemical variables:

refereed paper

3.5

!:

3 2.5

ii

i;

2

~

1.5

-+-Average of Somatic collphage LRV -a-Average of E. coli LRV _,._Average of Clostridium perfringens LRV

Figure 1. Pathogen log reduction value (LRV) over time.

Acknowledgments We wish to acknowledge t he fund ing of the Victorian Smart Water Fund and the project manager, Water Quality Research Australia. This project has been possible due to t he support of Melbourne Water and its Eastern Treatment Plant , as well as the many survey participants. We particularly wish to thank T erry Anderson and Michelle Carsen of Sout h East Water.

• Effluent Suspended Solids and E. coli LRV (0.95) • Suspended Solids Mixed Liqu or 1 and C. perfringens LRV

The Authors

(0.90) • Suspended Solids Mixed Liquor 2 and C. perfringens LRV (0.92) • Effluent NH 3 and C. perfringens LRV (-0. 93).

Conclusions It was found that few studies have isolated and separately monitored the activat ed sludge process, with more investigations focusing on downstream process units such as disinfection technologies and sludge han dling approaches. Pathogen red uction data varied for the secondary activated sludge process from arou nd 1.0 to 3.0 log 10 for different organisms (Table 3). Few studies had isolated the cause or effect of the log reduction, or related variabi lity with other operating cond itions. Most stud ies mentioned the physical process of sedimentation and adsorption as likely mechanisms contributing to the observed reduct ion d uring this process, and some demonstrated t his effect experimental ly. A correlation was reported for log reduction of pathogen ic protozoa with effluent pH, redox potential and total organic carbon. Others noted some correlation with mean cell residence time (MCRT) and mixed liquor suspended sol ids (MLSS), or effluent SS. Studies found no appropriate su rrogate that could be used for pathogenic protozoa, but data was shown to correlate phages with viruses.

Dr Therese Flapper (Email: t herese@waterfut ures.net.au) and Dr Daniel Deere are Directors at Water Futures, consultants specialising in the scie nce and risk management of wat er. www.thewaterhub .com. Dr Bradley Campbell is a Post Doctorate at Biotechnology Research Centre, La Trobe University, Bendigo, and is responsible for Pilot Plant operat ions and the monitoring program. Dr Judy Blackbeard is Manager, Water Recycling Research with Melbourne Water. Dr David Halliwell is Program Manager, Wastewater & Recycled Water Programs, Water Quality Research Australia, South Austral ia.

Literature Survey Aulicino, F.A. , A. Mastrantonio, P.Orsini, C.Bellucci, M.Muscillo and G. Larosa (1996) Enteric viruses in a wastewater treatment plant in Rome. Water, Air and Soil Pollution 91: 327-334. AwwaRF (2008). Effect of pathogen load on pathogen reduction by conventional treatment. Bonadonna L, Briancesco R, Ottaviana M, and Veschetti E (2002) Occurrence of Cryptosporidium oocysts in sewage effluents and correlation with microbial, chemical and physical water variables. Environmental Monitoring and Assessment. V 75, Pp 241 - 252.

Table 3. Summary of log reduction value (LRV) findings from the literature and data review. Study

Bukhari, Z., H.V. Smith, N. Sykes, S.W. Humphreys, C.A. Paton, R. W.A. Girdwood, and C.R. Fricker (1997) Occurrence of Cryptosporidium spp oocysts and Giardia spp cysts in sewage influents and effluent s from treatment plants in England . Water Science and Technology 35(11 ): 385-390.

LRV Viruses

Bacteria

0.5 - 1.5 Cryptosporidium 1.0 - 1.5 Giardia

1.0 - 2.0

1.0- 2.0

Australian literature review

1.0 Cryptosporidium 1.9 Giardia

1.0

1.8

Data review survey

1.0 Cryptosporidium 1.5 Giardia

1.5- 2.9

2.8

Carraro, E., E. Fea, S. Salva and G. Gilli (2000) Impact of a wastewater treatment plant on Cryptosporidium oocysts and Giardia cyst s occurring in a surface water. Wa ter Science and Technology: 41(7): 31-37.

Detailed data review

2.24

2.76

2.5

Casson, L.W. C.A. Sorber, J.L. Sykora, P. O. Gavaghan, M.A. Shapiro, and W. Jakubowski (1990) Giardia in

Protozoa

International literature review

60 FEBRUARY 2010 water

Caccia S, Giacomo M, Aulicino F and Pozio E (2003). Giardia Cysts in Wast ewater Treatment Plants in Italy. Applied Environmental Microbiology, June 2003, pp 33933398.

technical features


wastewater - effect of treatment. Water Pollution Control Federation Research, 62: 670 - 675. Chauret, C., N. Armstrong, J. Fisher, R. Sharma, S. Springthorpe, and S. Sattar (1995) Correlating Cryptosporidium and Giardia with microbial indicators. Journal American Water Works Association, 87(11 ): 76-84. Chauret, C., S. Springthorpe and S. Sattar (1999) Fate of Cryptosporidium oocyst s, Giardia cysts, and microbial indicators during wast ewater treatment and anaerobic sludge digestion. Canadian Journal Microbiology, 45(3): 257-262. Clancy, J.L., K.G. Linden and R.M. McCuin (2004) Cryptosporidium occurrence in wastewaters and control using UV disinfection. International UV Association, News 6(3): 10-14. Cram E.B. (1943) The effect of various treatment processes on the survival of helminth ova and protozoan cysts in sewage. Sewage Works Journal 15(6): 1119-38. Dai, X. and J. Boll (2003) Evaluation of Attachment of C. parvum and G. lamblia to soil particles. Journal Environmental Quality, 32: 296-304. DoE (1985) Parasites in sewage effluent. Department of the Environment. United Kingdom. Report No DWI0664. Funderburg S.W. and C.A. Sorber (1985) Coliphages as indicators of enteric viruses in activated sludge. Wa ter Research 19: 547-555. Gerba C.P. C.H. Stagg and M.G. Abadie (1978) Characterisation of sewage solid-associated viruses and behaviour in natural waters. Water Research 12: 805-812. Glass J.S. and R.T. O'Brien (1980) Enterovirus and coliphage inactivation during activated sludge treatment. Water Research 14: 877-882. Graczyk T, Lucy F, Tamang L, and Allen Miraflor (2007). Applied Environmental Microbiology, Mar 07, Pp 2013 - 2015. Hawkins, P.R., Swanson, P., Warnecke, M., Shanker, S.R. and Nicholson, C. (2000). Understanding the fate of Cryptosproidium and Giardia in storage reservoirs: a legacy of Sydney's water contamination incident. Journal Water Supply and Research Technology - Aqua, 49(6), 289-306. Irving, L.G. and F.A. Smith (1981) One-year survey of enteroviruses, adenoviruses, and reoviruses isolated from effluent at an activated-sludge purification plant. Applied and Environmental Microbiology 41(1): 51-59. Keller R., R.F. Passamani-Franca, F. Passamani, L. Vaz, S.T. Cassini, N. Sherrer, K. Rubim, T.D. Sant'Ana and R.F. Goncalves (2004) Pathogen reduction efficiency from UASB + BF effluent using conventional and UV post-treatment systems. Water Science and Technology 50(1):1-6. Ketratanakul A. and S. Ohgaki (1988) Indigenous coliphages and RNA-F specific coliphages associated to suspended solid in activated sludge processes. Water Science and Technology 21: 73-78. Kim, T.D and H. Unno (1996) The role of microbes in the removal and inactivation of viruses in a biological wastewater treatment system. Water Science and Technology 33: 243-250. Lauria-Filgueiras, A.I. and E. Hofer (1998) Diversity of Campylobacter isolat es from three activated sludge systems. Membrane Institute Oswaldo Cruz 93(3): 295-298. Leong L.Y.C. (1983) Removal and inactivation of viruses by treat ment processes for potable water and wastewat er - A review. Water Science and Technology 15(5): 91 -114. Madore M.S., J.B. Rose, C.P. Gerba, M.J. Arrowood and C.R. Sterling (1 987) Occurrence of Cryptospordium oocysts in sewage effluents and selected surface wat ers. Journal Parasitology 73: 702-5. Martinez, V.M.I., M.E. Ares-Mazas, D. Duran-Oreiro and M.J. Lorenzo-Lorenzo (1992) Efficacy of activated sludge in removing Cryptosporidium parvum oocysts from sewage. Applied and Environmental Microbiology 58(11 ): 35 14-3516.

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Mayer, C.L. and C.J . Palmer (1996) Evaluation of PCR, nested PCR, and fluorescent antibodies for detection of Giardia and Cryptosporidium species in wastewater. Applied and Environmental Microbiology 62(6): 2081-2085. Medema, G.J ., F.M. Schet s, P.F.M. Teunis and A.H. Havelaar (1998) Sedimentation of free and attached Crytposporidium oocysts and Giardia cysts in water. Applied and Environmental Microbiology 64(11): 4460-4466. Moore, B.E. , Sagik B.P. and Malina J.F. (1975) Viral association with suspended solids. Water Research 9:197-203.

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FEBRUARY 2010 61


Omura T., M. Onuma, J. Aizawa, T. Umita and T. Yagi (1989) Removal efficiencies of indicator micro-organisms in sewage treatment plants. Water Science and Technology. 21: 119-124. Ozaki M, Suwa M, Suyama A, Wirojanagud W, Tantemsapya N, Homwong J, and Shipin O (2005). Survey of sources, routes and fate of pathogens in the water environment in monsoon Asia. Payment, P. Fortin, S. Trudel , M (1986). Elimination of human enteric viruses during conventional waste water treatment by activated sludge. Canadian Journal of Microbiology, V32. Pp922-925. Payment, P. , and Trudel, M. 1987. Detection and quantitation of human enteric viruses in waste waters: increased sensitivity using a human immune serum globulin - immunoperoxidase assay on MA-104 cells. Canadian Journal of Microbiology, 33: 568-570. Payment P, Plant e R, Cejka, P (2001) Removal of indicator bacteria, human enteric viruses, Giardia cysts, and Cryptosporidium oocysts at a large wastewater primary treat ment facility. Canadian Journal of Microbiology, V 47, pp 188-193. Payment (2003), Waterborne pathogens, occurrence in wastewater, removal by treatment and risk assessment of effect on public health. INRS Institute Armand-Frappier, University of Quebec, Canada. Payment, P and Pinter, K (2006). Waterborne pathogens - a critical assessment of methods results and data analysis. Revue des Sciences de /'Eau. Vol 19(3). Pp 233-245. Reinoso R and Becares E (2008). The occurrence of intestinal parasites in swine slurry and their removal in activated sludge plants. Bioresearch Technology Vol 99 . Pp 6661 - 6665. Robertson L, Paton C, Campbell A, Smith G, Jackson M, Gilmour R, Black S, Stevenson A, and Smith H (2000). Giardia cysts and Cryptosporidium oocysts at Sewage treatment works in Scotland, UK. Water Research, V 34 N 8, Pp 2310 - 2322 . Rolland, D., Ph. Hartemann, J.C. Joret, A. Hassen and J.M. Foliguet (1983) Evaluation of the load of enteroviruses in a biological wastewater treat ment plant. Water Science and Technology 15: 115-121. Robertson, L.J. C.A. Paton, A.T. Campbell, P.G. Smith, M.H. Jackson, R.A. Gilmour, S.E. Black, D.A. Stevenson and H.V. Smith (2000) Giardia cysts and Cryptosporidium oocysts at sewage treatment works in Scotland, UK. Water Research 34: 2310-2322. Rose, J.B. (1996). Water reclamation, reuse and public health . Water Science & Technology Vol 55 No 1-2 pp 275-282. Rose, J.B., D.E. Huffman, K. Riley, S.R. Farrah, J. O. Lukasik and C.L. Hamann (2001 ) Reduction of enteric microorganisms at the Upper Occoquan Sewage Authority Water Reclamation Plant. Water Environment Research 73(6): 711-720. Rose, J.B. et al. (2004) (WERF Project). Reduction of pathogens, indicator bacteria and other organisms by wastewater treatment processes. IWA Publishing . Shimohara E., S. Sugishima, and M. Kaneko (1984) Virus removal by activated sludge treatment. Water Science and Technology 17: 153-158.

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St adterman K.L. , A.M. Sninsky, J.L. Sykora and W. Jakubowski (1994) Removal and inactivation of Cryptosporidium oocysts be activated sludge treatment and anaerobic digestion Water Science and Technology 31: 97-104. Suwa, M. and Y. Suzuki (2001) Occurrence of Cryptosporidium in Japan and countermeasures in wastewater treatment plants. Water Science and Technology 43: 183-186. Tanji, Y. Mizoguchi, K. Yoichi, M. Morita, M. Hori, K. Unno, H (2002). Fate of coliphage in a wastewater process. Journal Biological Science and Biological Engineering, Vol 94. No 2. Pp 172 - 175. Van der Drift , C., E. van Seggelen, C. Stumm, W. Hol and J. Tuinte (1977) Removal of Eshcerichia coli in wastewater by activated sludge. Applied and Environmental Microbiology 34(3): 315-319 . Walker-Coleman, L. (2003) Removal of Cryptosporidium and Giardia at a Central Florida Water Reclamation Facility. Report by the Florida Department of Environmental Protection. Yanko, W.A. (1993) Analysis of 10 years of virus monitoring data from Los Angeles County treatment plants meeting California wastewater reclamation criteria. Water Environmental Research 65(3): 221-226.

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Zhang, K and Farahbakhsh K (2007). Removal of native coliphages and coliform bacteria from municipal wastewater by various wastewater treatment processes: Implications to water reuse. Water Research V 41. Pp 2816 - 2824.

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~ refereed paper

water recycling & reuse

EFFICIENCY OF RO FOR REMOVAL OF CHEMICAL CONTAMINANTS C Rodriguez, R Lugg, P Van Buynder, B Devine, A Cook, P Weinstein Abstract This paper presents an overview of the chemical results of the Premiers Collaborative Research Project: Characterising Secondary Treated Wastewater for Drinking Purposes Following Reverse Osmosis Treatment. The chemical groups analysed include a broad range of analyt es with different physical and chemical characteristics and toxic effects. Their potent ial human health impacts at the concentrations observed in the post RO water were evaluated using a screening health risk assessment methodology. The results confirm that reverse osmosis is effective in control ling chemical hazards and reliably producing recycled wat er suitable for augmenting, through indirect potable reuse, public drinking water supplies. Specific health recommendations, detailed in the tech nical report, were developed for the monitoring of the Water Corporation's three-year groundwater replenishment trial

Background Perth, like many other cities in Australia, has been experiencing water shortages exacerbated in recent years by both rapid population growth and drying c limate. Predicted climate changes are expected to bring dryer and hotter conditions in Western Australia and up to a 10-30% decrease in rainfall during the winter and spring months by 2100 (Passey 2003). One of the options

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64 FEBRUARY 2010 water

considered to ensure sustainability is groundwater replenishment (GWR) to supplement drinking water supplies. Perth is unique among Australian capital cities in that it is the on ly city that derives more than half of its drinking water from groundwater. GWR has the capacity to store large volumes of water and it is considered a rainfall independent source of water. Currently only 6% of the treated wastewater produced in the metropolitan area is recycled for industrial use but the Water Forever draft plan sets a target of 60% of wastewater recycled in the metropolitan area by 2060 (Water Corporation 2009). In order to characterise contaminants in recycled water, a two-year interagency monitoring program was conducted. The study aimed to characterise cont aminants in the secondary treated wastewater of the three major wastewater treatment plants (WWTPs) in Perth, and to evaluate the recycled water quality after advanced treatment using microfiltration (MF) and reverse osmosis (RO) at the Kwinana Water Reclamation Plant and the Beenyup Pilot Plant A screening health risk assessment methodology, based on a th ree-tiered approach was used to calculate Risk Quotients (RQs) before and after the advanced treatment process (Rodriguez, et al. 200 7). RQs were calculated as the ratio of the measured concentration and the health value . RQs were calculated using the median (RO median) and maximum (RO max) contaminant concentration in wastewater and post RO water. Parameters with guideline values from the Australian Drinking Water Guidelines (NHMRC and NRMMC 2004), WHO (WHO 2006), USEPA (U.S. EPA 2008) or other organisations were classified in tier 1 and were selected in that order of priority. Parameters with toxicological information available for the derivation of health values in drinking water were classified in tier 2. For those chemicals without guideline values or toxicological information, health values were calculated using the threshold of toxicological concern (TTC) approach (Kroes, et al. 2004; Kroes, et al. 2005; NRM MC EPHC & NHMRC 2008).

Results A total of 19893 individual measurements of a total of 355 analytes were analysed, excluding field blanks, trip blanks and replicates. The distribution of analytical samples by event and location is summarised in Table 1. The list of chemical groups analysed included a broad range of parameters with different physico-chemical characteristics and toxic effects. For nine of the twenty one groups listed in Table 2, all the tested chemicals were detected. The lowest percentage of det ection in secondary treated wastewater was for pesticides with 10 detected out of 117.

Metals The majority of the tested metals were detected in the secondary wastewater of the three WWTPs. Arsenic, cobalt, cadmium, mercury and beryllium were not detected in any of the samples. Aluminum and iron were occasional ly detected at levels above the aesthetic health standards (RQmax above 1) in the secondary treat ed wastewater. However, RQ(max) and RQ(median) were below 1 for all post RO wat er samples.

Pesticides Atrazine, simazine, 2,-D, Chlorpyrifos ethyl, MCPA, metolachlor, piperonyl butoxide, propiconazole, triclopyr and triflurali n were detected in the secondary treated wast ewater. RQ(median) was equal t o or above 1 for atrazine, propiconazole and triflural in. However, after RO, the RQ(median) for the above mentioned pesticides, were 0.0025, 0.001 and 0.0095 respectively. Metolachlor was the only pesticide detected post RO water on one occasion. However, the detected concentration (0.08 µg/L) was below the guideline value of 2 µg/L (RO=0.04) and the health value of 300 µg/L

Results from a two year monitoring program in Perth, WA.

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water recycling & reuse

refereed paper

Table 1. Frequency of samples by event and location. Event

Month

No days

Year

Sample

Location

Total GW

Grab

1

November

4

2006

2531

sww

Water Reclamation Plant Before MF

Comp

2786

255

58

0

After MF

After RO

Dam

Sub Total

K

B

K

B

K

B

K

1006

0

193

0

779

0

750

2728

0

0

3055

2

May/June

6

2007

3226

1685

4911

701

1155

280

0

1387

0

1388

3 4

September

6

2007

2002

1974

3976

0

0

1051

819

97

97

1045

867

0

3976

January

6

2008

1721

1223

2944

493

495

710

0

0

512

734

0

2451

5

April

5

2008

1318

1384

2702

0

0 268

457

635

0

197

436

709

0

2434

6

June

5

2008

1241

1279

2520

0

0

500

595

90

268

430

637

0

2520

7

October

2

2008

54

0

54

0

0

0

18

0

18

0

18

0

54

4590 2965 750 17218 1767 580 12093 7800 19893 1252 1423 3789 2777 Total 32 Comp, composite; GW, groundwater; SWW, Subiaco wastewater; MF, microfiltration; RO, reverse osmosis; K, Kwinana Water Reclamation Plant; B, Beenyup Pilot Plant.

THMs were detected in 84% of the wastewater samples followed by HAAs (14%) and haloketones (6%). RQs for DBPs below limit of detect ion (n=14) were below 1. Detections of DBPs were greater in the post RO water than in t he wastewater for some samples. Their formation during the advanced treatment and the lower rejection of TH Ms through the RO membranes may explain the higher concentrations of these DBPs in the post RO water samples. Of 23 DBPs detected in the post RO water, RQ(max) was above 1 for bromodichloroacetaldehyde and dibromoacetaldehyde both calculated using the ne. None of the RQ(median) post RO were above 1 and for 13 of the 23 DBPs (56%) the RQs were one to four orders of magnitude below 1.

Proportion of detection in wastewater ranged from 3.5% for NEMA to 93% for NOMA. RQ(max) was above 1 in the wastewater for all n-nitrosamines except NDPhA. RQ(med ian) was above 1 for NOMA, NEMA and NMOR in secondary treated wastewater.The overall median concentration of NOMA in post RO was 5 ng/L. NOMA concentrations after RO were higher at Kwinana Water Reclamation Plant (mean=8.5 ng/L, max=30 ng/L) compared with Beenyup Pilot Plant (mean =4.8 ng/L, max 9 ng/L). All n-nitrosamine RQ(median) were below 1 in the post RO water. In post RO, NOMA was occasionally above the AGWR (Phase 2, 2008) value of 10 ng/ L. However, the guideline value is very stringent, being a tenth of the WHO Guidelines for Drinking-Water Quality (2008) and the proposed 2009 draft Australian Drinking Water Guidelines (ADWG) value of 100 ng/L.

N-nitrosamines

voes

All n-nitrosamines were detected in both wastewater and post RO water.

1,2-dichlorobenzene (94.6%) followed by tetrachloroethene (83.8%) and carbon

(RQ=0.0003). None of t he pesticides have a RQ above 1 in the post RO water.

DBPs

disulfide (80.0 %) were the more common ly detected VOCs in wastewater. In the post RO water the most commonly detected voes were 1,2-dichlorobenzene (89. 7%), chloromethane (62.1 %) and carbon disulfide (47.1 %). The median concentration range from 0.2 Âľg/L for 1,2-dichlorobenzene to 0.01 Âľg/L for 1,2-dichloroethane. Al l calculated RQs for detected voes were below 1 and none of the calculated RQ(max) in the post RO water was above or near 1. The highest RQ(max) was for 1,3-dichlorobenzene (RQ=0.17).

PAHs Individual potency equivalency factors (PEF) were calculated using the median concentrations of each detected PAH to BaP concentrations in wastewater and post RO water respectively. The values of every single TEF reported (Nisbet and LaGoy 1992; MOE 1997; Larsen and Larsen 1998) were used to calculate TEQs. RQ (median) PAHs in RO water expressed as TEQ was below 1.

Table 2. Total number of analytes tested and percentage of analytes detected in secondary treated wastewater. Parameter

n

Detected (%)

Volatile Organic Compounds (VOCs)

59 17

45.8

Polycyclic aromatic hydrocarbons (PAHs) Dioxin and Furans

17

23.5

83

Polychlorinated biphenyls (PCBs)

12

75

100

Gross alpha and gross beta particle activity

2

100

100

Hormones

4

50

4

100

3

100

n

Detected (%)

Trihalomethanes (THMs)

6

100

Haloacetic acids (HAAs)

9

89

Haloacetonitriles

6

Haloaldehydes

6

Haloketones

4

Parameter DBPs

100

Chloropicrin

1

100

Complexing Agents

N-Nitrosamines

9

100

Anions Other Chemicals

12

75

Antibiotics

10

90

Metals

29

65.5

Iodinated Contrast Media

8 20

63

Pesticides

117

8.5

85

Pharmaceuticals

Other Pharmaceuticals

66 FEBRUARY 2010 water

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water recycling & reuse Dioxins, Furans and Dioxin-like PCBs None of the samples analysed were above the health standard of 16 pg TEQ/L, using either the middle bound or the upper bound TEO (Van den Berg, et al. 2006) calculated from the 29 congeners. The TEO (middle bound) of all dioxin-like compounds produces a combined TEO of 3.34 pg TEQ/L before MF and a 2.45 pg TEQ/L after RO. Expressed as risk quotients these values were below 1 (RO before MF=0.21 and RO after RO=0.15). Gross alpha and gross beta None of the samples were above the ADWG screening level of 0.5 Bq/L for gross alpha or gross beta particle activity in wastewater (with 4°K contribution excluded). Maximum gross alpha particle in the post RO water was 0.035 Bq/ L and the maximum gross beta (excluding 4°K) particle activity was 0.03 Bq/L, wh ich corresponds to a RO max of 0.07 for gross alpha and 0.06 for gross beta particle activity respectively. Pharmaceuticals Calculated RQs(median) in wastewater were one to five orders of magnitude below 1. Diclofenac was the pharmaceutical with the highest RQ(median)=0.023. None of the RQmax was above 1 in the secondary treated wastewater and calcu lated RQs after RO were three to seven orders of magnitude below 1. Results from other chemical groups listed in Table 2 were all below levels of health significance in the RO water. Conclusions Th is study confirms that reverse osmosis (RO) is effective in i) substantially reducing chem ical hazards in treated waters and ii) reliably producing an end-product water suitable for augmenting public drinking water supplies. A range of chemical c ontaminants were all removed to levels below health significance. The outcomes of this research allowed the development of specific health recommendations for the Water Corporation groundwater replenishment trial (GWRT) in Western Australia. The objective of the GWRT is to treat the secondary wastewater from the Beenyup WWTP using advanced treatment (ultrafiltration, reverse osmosis and ultraviolet disinfection) and inject up to 5 MUday into the confined Leederville aquifer at a depth of approximately 200 metres for a trial period of three years. The recycled water is planned to be injected in a P3 drinking water source protection area (about 3 kms from drinking water abstraction bores). This study indicates that, provided the system are appropriately

implemented and monitored, the resulting water will pose negligible risks to the environment or human health. The Authors Clemencia Rodriguez, Senior Project Officer and Richard Lugg, Principal Medical Consultant, are with the Western Austral ian Department of Health. Clemencia Rodriguez, Paul Van Buynder, Brian Devine and, Angus Cook are Researchers in the School of Population Health, The University of Western Australia. Phil Weinstein is Deputy Head in the School of Population Health, The University of Queensland. Email: Clemencia.Rodriguez@health.wa.gov.au References Kroes, R., J. Kleiner, et al. (2005). "The threshold of toxicological concern concept in risk assessment." Toxicol Sci 86(2): 226-230. Kroes, R., A. G. Renwick, et al. (2004). "Structure- based thresholds of toxicological concern (ITC): guidance for application to substances present at low levels in the diet." Food Chem Toxicol 42(1): 65- 83. Larsen, J. C. and P. B . Larsen (1998). Chemical carcinogens Air Pollution and Health T. R. S. o. Chemistry. Cambridge, U.K: 33- 56. MOE (1997). Polycyclic Aromatic Hydrocarbons (PAH). Part 1: Hazard Identif ication and Dose-Response Assessment. Standards Toronto, Ontario, Ontario Ministry of the Environment and Energy (MOE). NHMRC and NRMMC (2004). Australian Drinking Water Guidelines. Artarmon, NSW, National Health and Medical Research Council and Natural Resource Management Minist erial Council: 615 p. Nisbet, I. C. and P. K. LaGoy (1992). "Toxic equivalency factors (TEFs) for polycyclic aromatic hydrocarbons (PAHs)." Regul Toxicol Pharmacol 16(3): 290-300. NRMMC EPHC & NHMRC (2008). Aust ralian Guidelines for Water Recycling. Phase 2: Augmentation of Drinking Water Supplies. Canberra, Natural Resource Management Ministerial Council, Environment Protection and Heritage Council and the National Health Medical Research Council: 173

p. Passey, R. (2003). Uncertain Harvest: The Predicted Impacts of Global Warming on Australian Agriculture, The Australian Wind Energy Association and Climate Action Network Australia. Rodriguez, C., P. Weinstein, et al. (2007). "A proposed approach for the assessment of chemicals in indirect potable reuse schemes." J Toxicol Environ Health A 70(19): 1654-1663. U.S. EPA. (2008). "Drinking water contaminants." 2008, from http://www.epa.gov/OGWDW/contaminants/index.html. Van den Berg, M. , L. S. Birnbaum, et al. (2006). "The 2005 World Health Organizat ion reevaluation of human and mammalian toxic equivalency factors for dioxins and dioxin-like compounds. " Toxicol Sci 93(2): 223-41. Water Corporation (2009). Water Forever: Directions for Our Water FutureDraft Plan. Perth. WHO (2006). Guidelines for Drinking-water Quality - Incorporating First Addendum to Third Edition - Volume 1: Recommendations. Geneva, World Health Organization.

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~ refereed paper

water recycling & reuse

EFFECTIVE REMOVAL OF PATHOGENS AND MICROPOLLUTANTS BY OZONE AND GAC J Reungoat, M Macova , S Carswell, B I Escher, J F Mueller, W Gernjak, J Keller Abstract Th is study evaluated the biological and chemical quality of the water produced by a full- scale reclamation plant based on the combination of ozonation and activated carbon filtration. The biological quality of the final water was assessed by t ests to detect the presence of pathogens. The chemical quality was assessed by the quantification of micropollutants (pharmaceuticals and pesticides) along the treatment train. Moreover, bioassays were used as complementary tools to evaluate the level of various biological adverse effect s induced by the water. The resu lts suggest that it is possible to produce reclaimed water of a quality comparable t o reverse osmosis treated water without the problem of disposal of the concentrate stream.

Introduction With the ever increasing pressure of the population on natural resources and t he threat of climate change consequences, wastewater reclamation for indirect potable reuse has become of growing interest to secure a safe water supply. To date, many of the large reclamation schemes operating in the world rely on the combination of microfiltration and reverse osmosis (MF/RO) to provide a physical barrier to biological and chemical hazards. The major drawback of this technology is that it prod uces a concentrate waste stream equivalent to about 15% of the treated volume, limiting the recovery efficiency of the process to 85%. Moreover, this stream has high salt and other compounds concentrations which make it very difficult to discharge in water bodies other than the open sea to avoid major impacts on the environments. Therefore, alternatives to MF/ RO have

to be developed to promote indirect potable reuse for inland locations. But can these alternatives produce water with a quality suitable for indirect potable reuse?

Materials and Methods The reclamation treatment train of the South Caboolture Water Reclamation Plant (Old) consists of the following steps: denitrification, pre- ozonation (2 mg.L·1), coagulation/flocculation/ dissolved air flotation-filtration (DAFF), main ozonation (5 mg.L·1), activated carbon filtration (18 min contact time) and post-ozonation (2 mg.L· 1). The influent water comes directly from the Caboolture (Old) nutrient removal act ivated sludge plant of 40,000 equivalent people, a storage tank between the two plants ensures a continuous flow rate (approximately 8,000 m 3 .d·1) in the reclamation plant. Biological performance data were kindly provided by the plant operator. Samples were collected weekly in tripl icates from the final effluent of the plant in the period of March 2006 to Apri l 2007 to t est for the presence of Clostridium perfringens, Escherichia coli and somatic coliphages. Another sampling campaign was carried out over one month in 2008 to perform chemical analysis and bioassays. Four composite samples (over 24 h) were col lected from the influent and the effluent flow of the reclamation plant as well as after each treatment step in the process train. For dissolved organic carbon (DOC) measurements, samples were fi ltered through a 0.45µm membrane before

membrane processes.

For micropollutants analysis, samples were concentrated using solid phase extraction (SPE) within 24 h, and later analysed by HPLC/MS-MS to measure the concentration of 56 pharmaceuticals and 28 pesticides, with a limit of quantification (LOO) of 0.01 µg/L for most analytes. For bioassays, water samples were concentrat ed via SPE before being diluted to determine full dose response curves. Results were generally expressed as toxic equivalent concentrations, TEOs. TEOs represents the concentration of a given reference compound that would be required to produce the same effect as the mixture of the various different compounds in the sample. The following biological adverse effects were evaluated: nonspecific toxicity (bioluminescent inhibition test), estrogenicity (E-SCREEN assay), genogenicity (UMU assay), phytotoxicity (PSII inhibition I PAM assay), neurot oxicity (Acetylcholinesterase inhibition assay) and dioxin-like effects (Ah receptor response - CAFLUX assay).

Results and Discussion A summary of the resu lts of the biological tests is presented in Table 1, during the period tested , under normal operating conditions; none of the pathogens investigated was detected in the fi nal water. These results show that the treatment process is capable of achieving a biological quality suitable for indirect potable reuse. Somatic coliphages were detected in three out of

Table 1. Summary of biological tests results. Parameters

An alternative to

performing non -purgable organic carbon analysis.

Clostridium perfringens (cfu/100 ml)

Escherichia coli

Somatic coliphages

(cfu/100 ml)

(cfu/100 ml)

Number of samples

51

51

Number of positives

0

0

39 0

water FEBRUARY 2010 69


GJ

water recycling & reuse five samples collected d uring a period when the ozone generators were operatin g on a lower ozone production. This show s the importance of the ozonation steps for the removal of pathogens and t hat ozone dose is a key parameter. Fifty-four com pounds were detected in the influent with a median concentration above t heir LOO. The concentrat ions or these compounds ranged from 0.01 µg.L·1 to 2.10 µg.L·1, except for gabapentin w hich ranged from 5.63 µg.L·1 to 6.50 µg.L· 1 . The influent DOC was between 14.2 and 19.7 mg.L· 1 . The development of the number of compounds detected along t he treatment train is shown on Fi gure 1. The first treatment steps, i.e. denitrification, pre-ozonation and DAFF, had no influence on the number of compounds detected and their concentration generally decreased by less than 20% . In t he meantime, the DOC was reduced by 40 to 50% in t he DAFF stage. Ozonat ion reduced the concentration of the compounds generally by more than 75% and 26 compoun ds were removed below t heir level of quantification indicating that oxidation by ozone is a very effic ient way to remove mic ropo llutants from treated wast ewater. During ozonation, t he DOC did not decrease significantly showing t hat oxidation of mic ropollutants and organic matter lead to the formation of by- products. The activated carbon filtrat ion was ab le to fu rth er reduce t he concentrati on of 25 compounds below LOO and only 2 compounds remained in the water: roxithromyci n and gabapent in w ith median concentrations of 0. 01 and 0. 70 µg .L· 1 respectively. Act ivated

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Figure 1. Number of compounds quantified and dissolved organic carbon (DOC) along the treatment train. Bars represent the number of compounds with a median concentration above the LOO (4 samples). Dots represent DOC on two different sampling days.

carbon also removed 20 to 30% of the DOC. Finally, the post- ozonation d id not have a significant effect on the micropo llutant c oncentrat ions or DOC. Four compounds were

what percentage of error can you afford? data loggers ~ sensors ~ weather stations ~ monitoring systems

7 0 FEBRUARY 2010 water

technical features


[;I

water recycling & reuse

refereed paper

Table 2. Biological adverse effects levels in the influent and effluent water of the reclamation plant.

Non-specific toxicity Estrogenicity Neurotoxicity Phytotoxicity Dioxin-like effects Genotoxicity

Decrease

Blank

0.48±0.20

79%

0.21±0.003

< 0.06 0.36±0.40 0.061 ±0.020 0.31 ±0.04 < 0.01

> 99% 88% 75%

< 0.02 < 0.3 < 0.01 0.08 < 0.01

Expression of results

Influent water

Effluent water

Baseline toxicity EqC (mg.L·1) Estradiol EqC (ng.L·1) Parathion EqC (µg.L·1)

2.3±0.7 6.0±2.1 3.1±1.0

Diuron EqC (µg.L·1) 2,3,7,8 TCDD EqC (ng.L·1)

0.25±0.10 0.83±0.26 0.23±0.10

Bioassay

1/ ECIRl.5

64% > 96%

EqC: equivalent concentration

detected in the final effluent: gabapentin (0.45 µg.L·1) , roxithromycin (0.01 µg.L·1), caffeine (0.02 µg.L· 1) and DEET (0.03 µg.L·1). The detection of caffeine and DEET was probably due to sampling and/or analytical variat ions. Table 2 gives the results of the bioassays for the influent and effluent water of the reclamation plant. The results are expressed as the equivalent concentration of a reference compound that induces the same effect as observed with the sample. The genotoxicity is expressed as 1/ ECIR1 .5, EC 1R1 .s represents how many times the samples have to be concentrated or diluted to elicit a t hreshold induction rat io {IR) of 1.5 (IR > 1.5 is considered significantly genotoxic). Table 2 shows that the level of all the biological adverse effects significantly decreased along t he treatment t rain. The denitrification and pre-ozonation stages had no significant influence on the level of biological adverse effects. On one hand, the coagulation/floccu lation/DAFF stage red uced acute cytotoxicity, genotoxicity, neurotoxicity and phytotoxicity by 40-70% compared to the pre-ozonated water. On the other hand, dioxin-like effects were not affected and estrogenicity increased which cou ld not be explained in this study. The main ozonat ion reduced all the biological adverse effects, by 36 to more than 90%, except neurotoxicity. Ozonation is known to lead to the formation of by-products wh ich is likely t he case here as t he DOC was barely decreased by the treatm ent. These byproducts are potentially of concern because they are largely unknown therefore it is difficult to evaluate their potential effects on the environment and the human health. Here, the bioassay results showed that the mixture of these by-products induced significantly lower levels of biological adverse effects compared to the mixture of parent compounds. The activated carbon adsorption was able

72 FEBRUARY 201 0 water

to further reduce non-specific toxicity, estrogenicity and neurotoxicity by 46, 95 and 84% whereas it did not significantly affect the other bioassays. Finally, post-ozonation had a negligible effect on all the bioassays and the levels measured in the effluent water were close to the blank levels (MilliQ water).

Conclusion The biological tests showed that pathogens were not detected in the final water of the reclamation plant. The combination of ozonation and activated carbon adsorpt ion was able to efficiently remove micropollutants from treated wastewaters; most of the compounds measured were below LOO in the final water. This indicates that concentrations were several orders of magnitude below the guideline values of the Australian Water Recycling Guidelines - Augmentation of Drinking Water Supplies. The bioassays results demonstrated a decrease of biological adverse effects consistent with the removal of micropollutants. They also confirmed that no negative effects appear to be generated from possible ozonation by-products at least on the range of tests used in this study. These processes are well known and already widely used in drinking water treatment, thus could be easi ly implemented in wastewater treatment plants to achieve further removal of micropollutants before discharge of the effluent to the environment or reuse of the wat er. These results also suggest that it is possible to produce reclaimed water of a quality comparable to reverse osmosis treated water processes for indirect potable reuse without using reverse osmosis. Nevertheless, before t his process can be recommended for indirect potable reuse, additional consideration needs to be given to the overall risk management strategies of the overall process train, as well as the

potential to form disinfection byproducts due to the remaining DOC levels.

Acknowledgment Funding support was obtained through the Urban Water Security Research Alliance. The authors thank Moreton Bay Water for giving access to the plant.

The Authors

Dr Julien Reungoat is a post-doctoral researcher at the Advanced Water Management Centre (AWMC), at The University of Queensland, under the supervision of Dr Wolfgang Gernjak and Professor Jurg Keller. Email j.reungoat@awmc.uq.edu.au. Dr Miroslava Macova is a postdoctoral researcher at the National Research Centre for Environmental Toxicology (EnTox) at The University of Queensland, under the supervision of Professor Beate I Escher and Professor Jochen Mueller. Email mmacova@entox.uq.edu.au. Stewart Carswell works at the Organic Laboratory of Queensland Health Forensic and Scientific Services, and is also a part time PhD student at EnTox.

References Full versions of this study are published online. Macova, M. , Escher, B.I., Reungoat, J., Carsw ell, S. , Lee, C.K., Keller, J. and Mueller, J.F. (2009) Monitoring the Biological Activity of Micropollutants during Advanced Wastewater Treatment with Ozonation and Activated Carbon Filtration. Water Research, In Press, DOI: 10.1016/j.watres.2009.09.025 Reungoat, J ., Macova, M., Escher, B.I. , Carswell, S. , Mueller, J.F. and Keller, J. (2009) Removal of micropollutants and reduction of biological activity in a full scale reclamation plant using ozonation and activated carbon filtration. Water Research, In Press, DOI: 10.1016/j.watres.2009.09.048.

technical features


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water efficiency

, refereed paper

WHAT'S THE RETURN ON A REBATE? G Watkins Abstract Water efficiency offers substantial benefits to our customers, the broader community and environment by delaying future capital works, less water extracted from the environment per household, reduction of residential electricity usage for hot water production and community involvement in resource efficiency.

MCW developed a broad rebate system to encourage existing households to convert over to more water efficient appliances. This rebat e scheme was introduced in January 2008 and has had over 2300 households take up at least one appliance change over. This wi ll save an estimated 70MUyr or 30kUhousehold/yr. For expenditure of $222/household, annualised over 30 years suggests we have provided this capacity for about $0.60/kl which is about a third of our current cost to provide water supply. With alternative water sources such as rainwater tanks water saving can be extended even further.

Introduction MidCoast Water (MCW) provides water and sewerage services to the urban areas of the Great Lakes and Greater Taree City Councils on the mid north coast of NSW. MCW has about 36,000 customers. Part of MCW's sustainable management of water provides for the efficient use of water as the first component before alternative sources and recycling are considered. Water efficiency offers a substantial benefit to our customers by delaying future capital works. With our current water supply headworks and status quo water usage compared to wat er efficiency usage, components such as increased st orage and treatment can be delayed by 1O to 15 years as shown in Figure 1. What this means to our customers is that a difference of $80/year can be deferred. Other triple bottom line benefits such as environmental and social impacts can also be achieved. Over the past 8 to 9 years, without the effect of water restrictions our customer's usage has declined as shown in Figure 2. The decline in water usage has been in part community awareness but more than likely the result of the introduction of a 'user pays' system. The user pays system commenced in

mcennves via a pomts system. 76 FEBRUARY 2010 water

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Over the last 8 to 9 years MldCoast Water's customer's water usage has declined while the number of connections has increased. This has been achieved without water restrictions. Most of the success has been attributed to the phasing in of a user pays system. This has been seen as a 'stick' approach, what we needed to further encourage water efficiency was a 'carrot'.

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2001,'()2 2002'03 2003J04 2004.'05 2005.08

20CMJ07 2007108

20<W09

Figure 2. Annual water usage compared to number of customers. 1998/99 at $0.35/kl to $1.95/kl in 2009/10. The pricing turning point was reached in 2001/02 at $0.55/kl. This is demonstrated in figure 3 where the meters of a duplex (2 units with a common wall) were incorrectly billed by accidental reversal of the meters such that Unit 2 received the bill from Unit 1 and Unit 1 received the bi ll from Unit 2. Both units are occupied by 1 person. As Unit 1 received a larger and larger bill for usage they reduced their water usage. While Unit 2 who received a modest bill for usage continued t o use water without apparent restriction. Once the error was corrected in March 2008 and the bi lls correctly issued, usage in Unit 2 reduced considerably. However 'user pays' is seen as a 'stick' approach and what was needed was a more customer informative and friendly 'carrot' approach to ensure our customers moved to higher water efficiency.

End Use Analysis To achieve water efficiency, an understanding of how and where water is used in the household wou ld be beneficial to demonstrate what wat er could be saved. A sample of our customer's usage specific to our conditions would provide the data we needed. The informat ion could then be used to drive our campaign to present the wat er efficiency message to all our customers, target education and rebates for older households.

technical features


THE TRENCHLESS PIPE REPLACEMENT SPECIALISTS


~ refereed p a per

water efficiency MidCoast Wat er has distributed about 120 'smart meters' over a range of our domestic customers for the purpose of evaluating water usage in the house and opportunities for water efficiency.

100

"'

it

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The period of analysis was leading into winter 2008 following 3 to 4 weeks of substantial rainfall . The smart meter results were adjusted to reflect how the smart met er participant's recent annual water usage compared to the rest of MCW's customers. From this comparison the average household used about 200 litres/person/ day (Up/d) including about 28Up/d for outside purposes. The biggest single c omponent of water usage was for the shower and clothes washing. Leaks represented a small component of wat er usage at around 1% of total water used . Leaks represented about 10% of participating households and were associated with water appliance operat ion past what was normal use i. e. toilet and taps run ning for extended periods . There were no continuous underlying leaks. The low outside usage may be associated w ith the preced ing wet period and cooler month.

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7}0511190 31/01/1ltt3 21/1CW1H 6 24/C711H 8 19/04l2001 14/011'2004 1Q/'10il200I S/07/2009 1/04/2012 Unit 2 pra fflMittcha~--. cOffKtty • • ~ - Unit 1 , - r n e u t f " c ~ ~ cOtNCtly auJgned Unk 1 newmet.r correc ... Md - Untt1Mfllnwlef'co"9C a11 ntd

Figure 3. Two units adjacent to one another but meters rotated on billing system.

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Efficiency for just the clothes washing machine, shower and toilet were examined using 'best usage' of 60Uload for clothes washing, once per day for 5 minutes @ 9Umin for shower and 3.8Uflush based on a 3/6L dual flush toilet. Current usage of the participating house was used to compare with ' best usage'. The results suggested 47Up/ d could be saved by water efficiency overall. The greatest wat er saving was 51 % of wat er cu rrently used in clothes washing machines, 39% in toilet flushing and on ly 17% in shower usage. Clothes wash ing and toi let fl ushing will have very little impact on customer lifestyles. Figure 4 shows the water efficiency that could be achieved based on our smart meter data.

....

150 111 ,4) ,3

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2008 Smart JMter lldjustlKI with water

I

Figure 4. MCW customers change in water usage in the typical household. The environmental and social benefits are not as easy to quantify as the financial benefits. The environmental benefits covered issues such as reduced water extracted from the environment to supply each household. Reduced greenhouse gas emissions were also a benefit by using less water not only in cold fixtures, with less energy used to deliver and transfer water t o and from each house but also less energy for hotwater systems at household level. Other environmental benef its for rainwater tanks, not necessarily providing water efficiency but providing an alternat ive water source, are reduced nutrients released into the stormwater system.

MCW needed a way to encourage and reward our existing customers to become water efficient and convert over old water inefficient appliances.

Social benefits include reduced infrastructure footprints on the community, education and socially responsible use of all resources.

MCW's direction was to develop a com prehensive incentive rebate scheme that allowed customer choice as to how each would tackle water efficiency.

78 FEBRUARY 2010 water

2001 Smart met~ • dJuated

efficie ncy

Carrot Rather than Stick

The fi nancial impact of deferring capital works, such as new water sources, through red uced demand was obtained. From th is a calcu lated net present worth of costs was made. This provided a benefit of about $450 per household.

IU

1r:: 0 -=e,c,h:-room--c • c=r o""' 11<1-, D ,,..,L-, u-nd,ry.,, a.,,. K•-•ho _ n_ •.,,. o-an~kln-g-0 -G1.,~."

Overall water usage may be reduced from 200Up/d to 153Up/ d by adopting water efficiency just in the areas of clot hes washi ng, showering and toilet flushing. Further reductions can be achieved by reducing outside and inside tap water usage.

Estimated water savings were made for each water appliance and these were converted to points for every 10kUannum saved, providing a maximum point score of 20. The next important question to answer was, what water efficiency was each point worth? A 'trip le bottom line' approach (financial , environmental and social) was made to define the val ue.

....

Previous TBL assessment s provided the split of fi nancial, environmental and social, knowing the value of the financial component we cou ld then provide an overall value of water efficiency of $1500 per household. lf(M SMOWU:HUD --

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Figure 5. MCW rebate point system.

Not all options of water efficiency are suitable to all customers, so we limited the maximum points available to 15, selectable from the 20 available. This provided $100/ point. MCW now had a value for water efficiency and a rebate points system which is shown in Figure 5. The rebate scheme has been available since January 2008 and will continue for 10 years to allow

technical features


water efficiency

I

... I ,... t ... l ... ... ,

progressive uptake of water efficient appliances and rainwater/grey water systems. During this time MCW wi ll also give away free restrictive washers as an alternative to shower head replacement. As of May 2009, 2340 participants have taken up the rebate and MCW has paid out $521,000 since the program commenced. Th is is an average expenditure of $222/household. Most have taken up a single rebate at this stage with only 140 taking up more than one rebate. Number of rebates by appliance is presented in Figure 6 where water usage was available for 2194 households, with strata properties excluded as they are not individually metered.

,...

'a

Based on this analysis approximately 40MUyr has been saved by these 1318 households or 70MUyr if extended to all 2340 households. This represents about 30kUhousehold/yr. For expenditure of $521,000 we have reduced water need or provided a further system capacity of 70MUyr, annualised over 30 years suggests we have provided this capacity for about $0.60/kl which is about a third of our current cost to provide water supply. Other benefits would include a slight reduction in wastewater flow and the energy to transport and treat wastewater flows. Using our smart meter data we were able, on a smaller scale, to examine changes in wat er use more definitively. A number of houses with smart meters have converted some fixtures to more water efficient ones. The average water usage change is presented for these properties in Figure 8 and shows what practical water efficiencies have been achieved: Once a household is water efficient, alternative water sources can obtain even more savings on centralised water supplies. My house's water usage, as an example in Figure 9 has water efficiency and a modest 8500 litre rainwat er tank with about 80m2 of roof area. The rainwater tank was connected to the whole house in early 2008. Approximately 90% of the water used can be supplied from the tank. I have gone from 110 to 120kUquarter in the mid 1990's to 1 to 6 kUquarter in 2008/09.

1000

15 E

l

Figure 6. Number of 'water smart' applicants.

n.--------------------,--

An analysis of the data collected has been undertaken using pre and post quarterly water meter usage data from those households that took up the rebate. Of the 2194 households only 1318 had a long enough period post appliance changeover to allow evaluation. The quarterly water meter readings for a 12 month period post appliance change-over and 24 months pre appliance change over were used to derive changes in water usage. The quarterly water meter readings are not necessary useful for this analysis as the quarterly readings are subject to seasonal variation and possibly also the general trend in less water usage. This analysis should be considered as an approximate method of comparison. Households with multiple rebate claims had a slightly greater reduction in water usage then single claimants. The results of this broad analysis of quarterly water meter readings and its impact on change in water use by appliance altered is shown in Figure 7.

refereed paper

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Figure 7. Water smart - water usage prior & after appliance change.

Fixture Winter OB Shower 40Ushower Toilet 8.5 1./flush Clothes washing 113 Uload Figure 8. Reductions achieved.

Summer09 35 Ushower 5.1 Uflush 65 Uload

% reduction 12.5% 40% 43%

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Figure 9. My water usage including water efficiency and 8500 litre rainwater tank. annualised over 30 years suggests we have provided this additional system capacity for about $0.60/kl which is about a third of our current cost to provide water supply. The incentive that MCW has provided has demonstrated that a non asset solution is a good business investment that minimises or delays future asset creation options.

The Author

Conclusion To encourage water efficiency in January 2008 MCW introduced a broad rebate system to allow the progressive conversion of old inefficient water appliances to more efficient ones. Over 2300 participants have taken up one or more rebates as of May 2009. The cost on average has been $222/ household to reduce water by 30 kUhousehold/yr. This capital cost

80 FEBRUARY 201 0 water

Graeme Watkins , a civil engineer is Manager, Strategic Operations for MidCoast Water, based in Taree NSW. Email graeme.watkins@midcoastwater.com.au

technical features


water efficiency

;-:J

refereed paper

SEQ's ONE TO ONE WATER SAVINGS PROGRAM A Turner, J Fyfe, M Retamal, S White, A Coates Abstract This paper provides an overview of the innovative One to One Water Savings Program implemented in the South East Queensland (SEQ) region of Australia in 2007. The program aimed to assist households classified as high water users (HWUs) to reduce their water demand during the worst drought on record. The program consisted of sending out a survey to over 79,000 HWUs using more than 800 Uhousehold/ day (Uhh/d) and for those that completed the survey, a personalised plan was provided on how to save water. The program had a unique combination of: a very large sample size (over 70,000 respondents); access to individual customer water meter readings; and availability of detailed household survey responses on water using practices. Due to this unique combination it was possible to investigate the suite of reasons why HWUs have above average water consumption. It was also possible to analyse how HWUs could save water to inform future water saving policy initiatives. The analysis outlined in this paper draws on an extremely important water usage dataset, of a size that has never been collated and analysed before in Australia. The research is of significant importance at a regional, national and international level and will be of significant interest to those water resource managers facing a drought situation and those involved in water forecasting and demand management interested in understanding how water is being used and could be saved.

Introduction The SEQ region of Australia has a population of 2.5 million. From early 2004 to the end of 2007 this large region experienced an unprecedented fall in dam levels, from just over 60% to less than 20%. The drought gripping the area was one of the worst on record. During this time strong measures were required to slow the depletion of the dam reserves through both demand and supply side measures (i.e. embedding water efficient behavioural pract ices into the community and developing new sources of water). To do this the Queensland Government set up the Queensland Water Commission (QWC) to develop and oversee the implementation of a diverse drought plan. Th is involved the implementation of water restrictions and short and long term demand and supply side drought measures from major water efficiency rebate programs through to the construction of the State's first major desalination plant. During this period restrictions were tightened breaking new ground for the region in terms of the extent of behaviour change expected by the community. The campaign included "Target 140" encouraging individuals to reduce household water usage to less than 140 litres per capita per day (LCD), where 2004/05 levels had been over 220 LCD. This campaign

Unpacking residential high water usage. 82 FEBRUARY 2010 water

Figure 1. Twelve (former) councils participating in the One to One Water Savings Program.

was so successful that other jurisdictions have subsequently adopted a similar approach (i.e. Victoria - "Target 155").

The One to One Water Savings Program As part of Level 5 water restrictions and "Target 140" the QWC released the One to One Water Savings Program. The QWC engaged the Local Government Infrastructure Services (LGIS) to implement the program which is an extraordinary water efficiency program in terms of both size and the timeframe in which it was completed. It involved: â&#x20AC;˘ identifying HWU households (classified as those households using more than 800 Uhh/d) in the 12 participating councils (refer to Figure 1); â&#x20AC;˘ providing a survey form to over 79,000 households in June 2007 (the Water Use Assessment Form) to find out why households were using so much water; â&#x20AC;˘ receiving and processing more than 92% of responses by September 2007;

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water efficiency

refereed pape r

• providing a Personalised Water Savings Plan to each household that responded (using > 140 LCD) advising them on how they could reduce water consumpt ion; • collating water meter read ings for each respondent post implementation of the One to One Water Savings Program; and • by February 2008 undertaking a major data analysis exercise on the survey results, socio-economic data and water meter reading data to unveil the reasons behind high water use to inform future water policy direction. Behind t he scenes LGIS engaged a team of special ists to develop t he survey, associated databases, cond uct social marketing surveys and analysis, design the survey responses and conduct data mining and analysis of the survey results and associated water meter readings. Due to its significant experience in water efficiency t he Institute for Sustainable Futures (ISF), at the University of Technology, Sydney, was engaged to assist in the development of the survey, the design of the personalised responses and subseq uent analysis of the survey responses and customer water dat a. The analysis aimed to investigate t he characteristics of HWUs, det ermine why they were using more water and how to assist HWUs to save water and ultimately inform future water policy in the region for this sub-sector.

Survey Information Collated and Analysis Tech niques Used The survey The survey (or Water Use Assessment Form) consisted of over 58 quest ions and sub questions. The information col lated was considered from an end use perspective, that is, both the level of efficiency of appliances and water use behaviour around t he home were invest igated. To aid the analysis component of t he program the questions were aligned where possible with standard Australian Bureau of Stat istics (2007) questions in order to enable comparison with State and Australia- wide norms. The informat ion provided by t he survey was broadly categorised into the following groups: • household statistics - rent/own, lot size, residence time, no. of occupants, age of occupants; • lifesty le indicators - ownership of a pool, spa, lawn, spec ial garden, pets, livestock; • behaviour - loads of washi ng and dishwashing, dishwashing activities, no. of showers and baths, garden activities; • uptake of technology, level of efficiency of different appliances and alternative water sources; • type of washing machine, dishwasher, toilet, shower, use of rainwater or groundwater; • uptake of subsid ies and rebates ;

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water efficiency • special circumstances - health conditions, home businesses, etc. • leaks

Analysis techniques and statistical methods A range of tech niques and statistical methods were used to analyse this unique data set. By using the combi nation of survey results, water meter data and socio-economic data it was possible to view the households and their water use from multiple perspectives. The methods used included: • frequency analysis • cross tabulation analysis and development of graphical outputs • basic demand management/ conservation potential options analysis • basic participant versus control comparison for a subset of data • regression analysis modelling (univariate and stepwise regression analysis of key variables and binary logistic regression) , • socio-demographic profiling and analysis using Mindshare a proprietary data analysis tool.

Summary of Findings The analysis cond ucted unveiled numerous new insights into the water usage of HWUs overall and for specific counci ls. The findings below provide a summary of key findi ngs that will be of use to the water industry more broadly.

refereed paper

Pre and post intervention The benchmark for water demand during the Level 4 restrictions in SEQ in the summer of 2006/07 was 140 LCD, reinforced by the "Target 140" campaign. A household using less than 140 LCD in this "summer" or "pre" period before the One to One Water Savings Program was considered "efficient", given the limited potential for outdoor water use due to restrictions rules. However, because the number of occupants within a household was not known before the survey forms were sent out, t o determine LCD consumption households were selected for inclusion in the program based on a household demand of 800 U hh/d or more. When later divided by the number of occupants stated in the survey responses it was found that 93% of the HWUs were correctly classified as "inefficient" (i.e. demand > 140 LCD). After households were select ed for the program and ret urned their surveys, a special meter reading was taken, which allowed an estimate of the co nsumption for a period of time (referred to as the "winter" or "post" period) t hat largely overlapped the period after t he program intervention. In the post period the HWUs reduced household demand significantly and the number of households usi ng less t han 140 LCD (and thus classified as "efficient") increased from 7% to 45%. This significant reduction is due t o a combi nation of comparing summer versus winter usage, the effects of the One to One Water Savings Program and other restrictio ns and demand management programs highly acti ve at that time.


~ refereed paper

water efficiency Table 1. Key characteristics. No.

Queensland and Australia-wide norms

Key characteristics

Across all councils Above average home ownership at 80% (ranging from 75% to 85% depending on counci l observed) 1

Queensland (69%), Australia-wide (72%)

2

High occupancy ratio of just over 4.6 (ranging from 4.46 in Gold Coast to as high as 5.13 in Beaudesert)

Queensland and Australia-wide (2.8) for detached dwel lings

3

High proporti on of tee nagers (ranging fro m 21 % to 27% depending on counci l)

Queensland (12%), Austra lia-wide (13%)

4

High pro portion of pools with an average of 50% (ranging from 14% to 63%)

Queensland (18%), Australia-wide (12%)

For majority of councils 5

High proportio n of households operating a small business 18% (15% to 21%) with 441 (3.5%) indicati ng high water use, 23% indicating medium and 73% indicating low.

No state or nation-wide comparison data available

6

High proportion of households with major leaks recorded, 22% (ranging from 19% to 33%)

No state or nation-wide comparison data available

Other key characteristics 7

High proporti on of households with rainwater tanks, 28% (ranging fro m 22% to 68%)

Queensland (22%), Australia-wide (19%)

8

Lower than average uptake of the HWWRS (excluding HWWS) at 11%

SEQaverage (excluding HWWS) 16.6%.

Notes - HWWRS - Home WaterWise Rebate Scheme, HWWS - Home WaterWise Service.

The average overall demand for the pre period for all 12 councils was 1,126 U hh/ d or 290 LCD. In the post (winter) period (where data was available for 10 of the 12 cou ncils) the overall demand dropped by over 35% to 724 Uhh/d or 174 LCD. None of the cou nci ls reduced their average demand to below 140 LCD, however, a hig h proportion of ind ividual households did (a shift fro m 7% to 45 %). Upon further inspection of water demand it appears th at the demand of the non HWUs in the 12 participating councils dropped by 22 % between th e pre and post periods whilst the HWUs reduced their overall average demand by 40%. At the same time it was observed that the HWUs in the pre period had an uptake of 11 % for th e Home WaterWise Service (HWWS). sim ilar to the overall uptake of the 12 participating councils. However, in the post period th e HWUs increased their uptake to 22% compared to 19% for the overall 12 participating councils, ind icating a positive uptake of demand management prog rams as a res ult of the One to One Water Savings Program . The drop in demand can therefore in part be explained by water savings assoc iated with the One to One Water Savings Program and other effi ciency acti vit ies. However, with insig hts from furth er analysis such as freq uency analysis, discussed below , it appears this drop in demand is also associated with significant discreti onary outdoor water demand being used by the HWUs in the pre (su mmer) mo nths despite Level 4 restrictions having been in place during the pre peri od analysed . This was further verified with th e res ults of a basic partic ipant versus control comparison for one of the councils with available data. Investigations in other areas of Queensland, namely Hervey Bay where Wide Bay Water has been able to observe the effectiveness of restrict ions through the use of smart meters, have found numerous cases of customers not complying wi th restri ctions in fo rce and using banned sprinklers at night (Tu rner et al 2009). Approximately 9% of the 79 ,843 households did not retu rn their survey forms. These "non compliant" househo lds had an average demand in the pre period of 1,225 U hh/ d. Whilst only 100 U hh/d (9%) higher than th e "co mpliant" group, this was statistically significant.

Frequency analysis characteristics of HWU households The investigations undertaken focused on determining why HWUs use so much more water on a per househo ld and per

86 FEBRUARY 2010 water

person basis. The HWUs were compared against state and nati onal norms where data was avai lable. The HWUs were fo und to have a higher proportion of end uses related to outdoor demand such as pools, lawns and gardens, which increase overall demand especially in the pre (summer) period. A higher th an average num ber of households were also fo und to have indoor appliances such as effi cient washing mac hines and dishwashers and a normal proportion of effi cient showerheads and dual flush toilets. This ind icates that these ho useho lds have a hig her demand primarily due to outdoor water use factors and it is highly likeiy th at these households used water in the pre (summer) period , which was outside water restrictions ru les. Key characteristics th at stand out when looking at frequency analysis, which may potentially have an im pact on water usage , are summarised in Table 1.

Household size compari son As part of the analysis it was observed th at whilst households with large fami lies use more water overall per day, such households are likely to become more effi cient (use less water) on a per person basis as th e nu mber of people in the household increases . This is most obvious with respect to outdoor water usage where for example in two similar houses with an occupancy of (a) 2 people and (b) 4 people with simil ar size gardens, the gard ens may requ ire a simi lar vo lume of water, yet the demand will actually be divided by 2 people for household (a) and 4 people in household (b). This increase in effi ciency is also likely to be observed fo r vari ous indoor appli ances, with which economies of scale can be achieved when shared by a larger group of people in a household. These econ om ies of scale are shown in Figu res 2, 3 and 4 for washing mac hines , dishwashers and showers respectively. As would be expected the economies of scale for showers are less pronounced. These resu lts are extremely usefu l for th ose practiti oners building end use demand fo recasting models th at integ rate detai led stock models. The results are also useful for targetin g water effi ciency progra ms. Various studies have evaluated th e savings associated with specific appliances . For example Kidson et al (2006) fo und that a pilot rebate program for 4A washi ng machines ach ieved a saving of 23 kUhh/a and Tu rn er et al (2005) reported on th e savings from various showerh ead programs bei ng approx imately 14 to 16 kUhh/ a. These stud ies

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water efficiency show actual savings achieved from these programs for an average household which is likely to have an average occupancy of approximately 3. By replacing washing machines (currently 80% inefficient) and showerheads (currently 45% inefficient) in HWU households with a high occupancy ratio, significantly higher water savings could be achieved for each single device replaced compared to those savings stated in the literature. This in turn would result in a low unit cost water efficiency program .

,.

Additional segmentation using water and frequency analysis The HWUs were segmented in terms of water demand to determine how much water various groups with specific household characteristics use, where water savings potentially exist and to gain a better understanding of the groups that might need to be targeted with a water efficiency program and associated comm unication strategy. Groups of interest are discussed below. When comparing renters versus owner occupiers, renters were found to use more water on average (d uring the post winter period) because t hey commonly have equipment and appliances that are less efficient than owner occupant households. Many efficiency programs concentrate on homeowners. Whilst HWU renters only represented 19% in SEQ, which may be similar for other areas, this still provides significant opportunity for savings and a targeted indoor wat er efficiency program tailored for renters that have specific barriers to implementing water efficiency. Households with businesses (18% of respondents) were found to have significantly higher water use than those without, in both the pre (summer) and post (winter) periods, 1,182 versus 1,113 Uhh/d and 770 versus 713 Uhh/ d respectively. However, it was found that the small number of households (441) that indicated they had high water use, dominated the water usage results. Small tai lored programs that investigate how to assist households with a home business classified as high water using co uld potentially achieve significant savings. A surprisingly high proportion of households (22%) indicat ed that they had major household leaks. Those that reported a leak (l ikely to be active in the pre summer period) had a much higher water demand (1,273 U hh/ d) than the average in the pre (summer) period across all councils. In the post (winter) period the average of the group reporting that they had the leak fixed reduced to 722 Uhh/ d. Those that reported a leak in the pre period which was repaired in the post period consistently demonstrated a reduction in demand often showing lower household demand than those reporting no major leak. This implies that major leaks are a significant contri buting factor to high water use and when fixed can substantially red uce demand. Limited research is available on household leaks but recent research carried out in Hervey Bay in Queensland (Britton et al, 2008) verifies t hat significant savings are possible through household leak detection and repair. The HWUs have a higher than average proportion of households with 11 -19 year olds ranging between 21 % and 27% , depending on council, compared to the State and Australia-wide averages of 12% and 13%. From the analysis households with a high proportion of teenagers, 11-19 year olds, use more water per person than 20-70 year olds. This is also the case for 3-10 year olds that used very

88 FEBRUARY 2010 water

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similar per person usage to the 11-19 year old teenagers. T his higher water usage in the 3-10 and 11-19 year old brackets is more evident in the post (winter) period when indoor water usage dominates. This findi ng implies that households with this age bracket have higher water use on a per person basis than households with predominantly adults (20-70 year olds), which could be related to behaviour around indoor end uses such as showers, wash ing machines and dishwashers. Creating schools programs that specifically target education on water efficiency in the 3-10 and 11-19 year olds could represent a major opportunity to save water in this age group, which will have long-term benefits as they grow older.

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water efficiency Households with outdoor uses such as swimming pools and lot sizes greater than 1,000 m2 , show higher than average water demand, especially in the pre (summer) period. In SEQ over 50% of HWU respondents had a pool but only 19 % of these indicated that they have a pool cover. In limited available research water savings of 8 kUhh/ a have been identified (although of marginal statistical significance) in areas such as the Gold Coast (Snelling et al, 2006) where pool cover water efficiency programs have been employed. In areas of high evaporation where HWUs are likely to have pools it would be advantageous to investigate a swimming pool cover program together with other pool water saving initiatives. The proportion of households with rainwater tanks was higher than the State average (28% versus 22% , ranging from 22 % to 68% depending on council). Analysis indicated households with a rai nwater t ank used marginally more than those that don't in the pre (summer) period (1,136 versus 1,121 U hh/d} but in

refereed paper

the post period this was reversed (692 versus 735 Uhh/ d) with savings being achieved in the winter months. Households with bores and spear pumps had consistently higher average demand in both the pre (summer) and post (winter) periods. Hence the existence of an alternative water source does not necessarily result in lower water use overall. Limited research on rainwater tank savings has been undertaken in Australia. In the Gold Coast (Snelling et al, 2006), it was found that rainwater tanks do provide a saving (approximately 20 kUhh/a) but this is significantly less than esti mated theoretical savings of approximately 70 kUhh/ a (Coombes and Kuczera, 2003). Hence there is significant sc ope to increase the water savings achieved from rainwat er tanks (both already installed and being installed} through connection to more indoor end uses to maximise potential savings. However, care needs to be taken in the rainwater configuration chosen to minimise the potential impacts on energy usage (Retamal et al 2009).

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Socio-economic analysis The HWUs group was found to be biased towards households with mid to high socio-economic standing (SES) and high fami ly orientation (56%), although the definition of high family orientation is a complex mix of measures obtained from census data such as household composition , number of vehicles , whether dwellings are being purchased and if females aged 35 to 54 in the household are employed part-time. It was found that there was very little difference in the occupancy ratio of these two groups (high and low family orientation). The HWUs had a fairly even split between high (31 %), medium (32 %) and low (26%) SES, with the disadvantaged only representing 12%. Splitting by family orientation the majority were high fami ly orientation at 72 %. Households with a high SES used more water per person (316 LCD), compared to the medium, low and disadvantaged (288 LCD) groups especially in the pre (summer) months


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water efficiency

REDUCING WATER USE FOR INDUSTRIAL AND COMMERCIAL CLEANING A Jones of constant use and total volumes, rather than transient peaks and short water use events.

Abstract The culture and expectation of how cleaning is approached varies widely between industries, and the increasing trends in monitoring and auditing water use are starting to highlight these variations. There are a number of trends that have become apparent when comparing the water efficiency of cleaning. When combined with technological advances, opportunities can be identified for expanding efficient practices into d ifferent areas and industries. For many sites and utilities, th is means a small adjustment in their approach to cleaning could dramatically reduce overall water use, but scepticism must be overcome.

Introduction Water used in cleaning is one of the key water use areas on the majority of commercial sites, and different sites and industries show a wide variety of technical and management-related approaches. Why is it that vast public areas in shopping centres are cleaned with negligible q uantities, while floor hosedown can account for the majority of water bills on small manufacturing sites? How is it that the daily cleaning of amenities throug h a large hospital can use less than the daily cleaning of a small pool deck? Through information gleaned from continuous remot e monitoring of water met ers in a variety of different projects in Sydney, this paper wil l draw together some general impressions about water used for floor and surface cleaning. Clean-In-Place (CIP) systems installed in custom designed manufacturing plant equipment and dishwasher/glasswasher units are not considered in this

Both technology and psychology are needed. 92 FEBRUARY 2010 water

An example of the equipment used is provided as Figure 1. The logger sends data to an online server via the next-G network, allowing temporary wireless installation on existing main meters, and on individual hosetaps on commercial sites.

Figure 1. Typical Meter and Logger Used for Flow Data Capture.

discussion, as the water use of these is typical ly controller by individual manufacturers, rather than site users and managers. But there are some principles that can be generalised about water used for rinsing floors, pool decks, cars, trucks, toi lets areas, conveyors, mixing tanks, cooking pots, trays, animal enclosures, tables and other similar surfaces. The purpose of this paper is to draw together wider principles that have been fou nd to be water efficient in particular industries or sectors. In many cases, these principles are fou nd to relate more to the history or culture of th.e work than to any tech nical requi rements. When combined with technology change, there is the opportunity for expansion of ideas and principles into areas and industries where these principles have not yet been trialled or considered.

Origin of Observations and Monitored Data The observations and flow monitoring data were generated through water efficiency audits of commercial and industrial sites, pilot trial studies of low flow spray guns, and water checks of various carwash facilities in Sydney. The data is gleaned from mechanical water meters attached to data loggers that average pulses (at 5 or 10 litres per pulse), averaged over 5 minute periods. Th is dat a format focuses on the flowrate

Other dat a was gathered using personal surveys of operators and cleaners about their cleaning practices and impressions of changing their processes to make use of lower flow devices.

General Principles of Cleaning Relating to Water Efficiency Flow rate The amount of water used per unit of time spent cleaning obviously has a very significant effect on the amount of water used. An operator or kitchen hand ri nsing down with open hose providing a laminar flow cou ld use 2 to 20 times the water used by a nearby staff member with a different orifice on a similar hose. An example is a catering kitchen in an entertainment facility. This had a number of hosepoints - one was a spray gun with a 15Umin flowrate, and another was an open hose with a 36Umin flowrate for the same purpose (Figure 2). It is often not easy to tell the flowrate without measurement, but the vast majority of fittings in all industries are above 20Umin - higher than average showers.

Frequency and duration More critical to overall water use, however, is the freq uency of use - how many minutes per day water is flowing for cleaning purposes. This is directly related to the roles and responsibilities of site staff - those who only have the job of keeping things clean

technical features


water efficiency (and little else to do) can spend much of the day wandering about wit h a hose. Sites where cleaning is done ext ernally or one of many other responsibilities can dramatically reduce the freq uency and duration of use. Frequency and duration are often influenced by t echnical and time fact ors also. A busy kitchenhand does not have time to turn off a tap every time they are fi nished wit h rinsing a pot or bench - and this may lead to hoses left running for significant durations compared t o the actual use requirement. A line operator (on the other hand) may need to sufficiently clean a tank or bay area before a product switch or shift change, and in this case a short duration is the single greatest priority. These factors were found t o create situations where a high flow fixture on a large (pressure boost ed) manufacturing site used significantly less than a kitchen or pool fac ility. For example the manufacturi ng site profile in Figure 4 shows similar flowrates to the kitchen profile (Figure 5) but the frequency of use leads to the kitchen using 10 t imes the water used on the manufact uring site

Figure 2. Open hose and Spray Nozzle in the same room.

This was attributed t o the targeting of the hand -held wat er spray to the most affect ed areas, and the use of soapy sponges to remove stuck dirt (in a single swipe) rather than water force gradually dislodging over the whole car surface.

Limiting the time of both deliberate and accidental use was therefore found to have the largest effect on red ucing water used for c leaning on all sites.

Hands-on vs hosing

Automatic washes were found to be the least efficient, despite the ability to use reuse water - as the water jets for a standard wash needed to be calibrated for a 'worst case' d irty car scenari o rather than simply washi ng until the car is c lean (Figures 5 and 6).

Analysis of competing car wash sites has highlighted the benefits of human effort in the cleaning process. The carwash sites where staff were employed t o wash and high-pressure rinse vehicles by hand were found to use

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technical features


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Figure 7. Site operator hosing broken glass bottles from under equipment. This same principle was found to apply in kitchen and on floors in manufacturing sites.

The effect of public areas safety Large shopping centres generally use a small amount of water to clean a very large area - through tank-filled floor cleaning units. While this is partially due to a lower loading of oi l and grease on these surfaces, the driver for such low water use is a safety related issue - an aversion to pooling on wet floors. The lack of moisture reduces the risk of slips and falls, wh ich ensures the centre is better covered against injury claims. Conversely, pools are expected to be wet, and are designed with surfaces that will retain maximum grip even when wet. This has the double effect of allowing constant hosing of the deck and floors during all times of day, and making the removal of debris with a hose more difficult (due to the rougher surface designed for grip). For this reason, excessive hosing is common at pool sites, but not in shopping centre public areas.

Figure 8. New spray gun of flowrate 12L/min 'cleans much better' than old gun with flowrate 30L/min at 800kPa.

ignored by operators (preferring the simplicity of hosing everything down). Figure 7 shows a site operator attempting to move a large amount of broken glass out from under a machine using a hose. Enforcing rules throug hout the site would dramatically reduce duration of water use, and at the same time reduce time taken and the effectiveness of the clean.

The impression of pressure Surveys of operators and cleaners in a variety of industries indicat ed that 'pressure' is a subjective concept. Swapping fixtures does not reduce water pressure, but the water flow which can influence the force and inertia of water as it moves through the air and impacts a surface. Users preferring higher flow for their cleaning were found to refer to ' better pressure' when they observed more of a 'kick back' effect from a hose being turned on, and more capacity for extra water to 'float' debris to drains. Neither of these attributes influence the ability for a water spray to rinse a surface free of

residue - this is affected by the force at the surface point. This force is dependent on nozzle design more than water volume. It was therefore identified that a barrier to water efficient pract ice was a misunderstanding about water pressure, and scepticism about the ability for effective cleaning with lower flowrates. There were examples recorded of hospital, manufacturing, kitchen and animal care sites that found significantly lower flow fixtures more effective at cleaning after a brief t rial. But the initial reaction is most commonly sceptical (Figure 8).

Helpful Technological Advances The development of a variety of technologies in recent years has opened up possibilities for cleaning to be done to a higher standard using less water.

Nozzle design Spray nozzles disrupt the laminar flow of water, and use the pressure force to introduce turbulence and aeration. This encourages smaller volumes of wat er to exit at significantly higher velocities.

Many manufacturing sites have existing procedures in place, and may already have the main floor stocked with brooms, squeegees, scoops and bins to allow solid waste to be quickly removed by solid objects (leaving the water use for a rinse of sticky or small remnants).

Nozzles are used for a variety of purposes, but in regard to commercial cleaning, variable pattern spray guns and pre-rinse spray valves allow rinsing and hosing of small solids to be done with less water and more force. Variable patterns provide versat ility - allowing the same unit to provide a wide mist and a focused zero degree jet.

These are excellent solutions and wou ld make a strong difference to water use if they were not so regularly

Nozzles are particularly effective with higher pressures - high pressure cleaners (with boost er

Following existing principles

96 FEBRUARY 2010 water

Figure 9. A Low Flow Spray Gun 'wide' pattern.

technical features


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pumps) allow very high water forces with flowrates comparable to an efficient basin tap.

Alternative forces

The improvement of other non-water cleaning tools is another area for consideration.

Long handles Brooms to clean under benches or equipment

Air pressure can be useful for outdoor areas (as with leaf blowers), as wetting some solids like leaves and dust can make cleani ng more difficult. Removing them dry with air can be quicker and more efficient.

It is common in kitchen and manufacturing areas for areas under equipment to be cleaned with an operator spraying a hose from a distance - even when cleaning heavy solid waste. In many cases, this is the single reason why a very high hose flowrate is used in a large area. An opportunity exists for the introduction of ergonomically appropriate brooms with a long reach length to remove solid waste from under tables and equipment. One difficulty with lower flowrate devices is that the lower volumes of water have less inertia. This can cause a spray to disperse or ' mist' if long distance spraying is required. More manufacturers are now taking this into account, offering lance options to extend the gun length and put the nozzle closer to the surface. Th is can dramatically improve effectiveness and ergonomics of use. Another new adaptation of this is the Wat erBroom, now available in Australia (Figure 10). This has a broom like shape, but instead of bristles there are a number of low flow nozzles very close to the floor surface.

This design allows fast and low flow cleaning of large surfaces, and the units are already part of rebate programs in some water utilities.

Also, the development of ergonomic and effective broom and hand scrubber products is progressing. In most cases, these are significantly more effective than using water only to clean large solid or 'caked' waste. Improvements t o these products allow them to be correctly specified to a particular task - allowing operators to use these tools more efficiently, and encouraging the continued use of these more effective methods.

Automatic shutoff

Alternative water supplies

With duration of usage being such a critical factor in the total water used, it is important that water is only flowing when it is used. Automatic shutoff is useful in ensuring that even in the case of a busy workplace or a careless operator, leakage or continual flow is avoided.

Automatic cleaning equipment has been making use of internal recirculation for some time - many commercial dishwashers and washing machines allow reuse of final rinse water f or initial ri nse.

Figure 10. 'Watermiser' Water Broom. Photo courtesy of Jeff Tresselt, www.walerwareproducts.com

Sites where fixtures are left running or leaks are common can use large volumes without noticing - automatic shutoff valves in spray gun triggers and timed tap valves can provide a technical

But on a larger scale, a similar opportunity exists on many sites - to make use of relatively clean water from cooli ng jackets, rainwater tanks or another nearby process in pre rinsing, cleaning of floors, and hosing outdoor areas. As the costs for basic water treatment continues to fall, more streams of single-use water can become available for a 'second use'.

Opportunities Identified The comparison of cleaning in different industries, combined with the influence of technology, creates a large number of variables and influencing factors. The following opportunit ies have been identified as common principles that can be applied across a relatively large proportion of the industry to reduce the water used for cleani ng.

Scrubbing and soaking In residential homes, car washes and kitchens, it is common practice to use soaking and scrubbing to remove solid, heavy, sticky, greasy or 'caked' waste from vessels, tools or equipment.

98 FEBRUARY 2010 water

technical features


water efficiency But on larger manufacturing , educational, health and animal care sites, the cu lture or available equipment only lends it to an operator cont inually hosing from a significant distance. Th is is not only wat er inefficient (requiring large flowrates and long durations), the cleaning effect tends to be less effective and slower. The implementation of procedures for basic soaking, followed by a manual clean (with well-maintained and effective manual tools) is expected to save time, money and water on many 'hose reliant' sites.

Brooms and floor cleaners A similar principle applied to floors, encouraging manual use of brooms and dedicated floor scrubbing units, allows much more targeted surface cleani ng. This is uncommon in health areas, kitchens and workshops where younger staff or cleaners are expected to hose down t he entire facility once or more per day - again as part of the c ulture. The use of these alternative tools also reduces the likelihood of staff 'killing t ime' with unnecessary cleaning - as is common with hosing.

Proximity When hoses are used, it is important that operators are as close t o the surface as possible. Both large manufacturing sites and relatively compact kitchens often have sparse hosepoints and relatively short hose lengths - encouraging staff to spray long distances. Longer hoses, more hosepoints, extensions on spray nozzles, the use of central cleaning bays, and improved accessibility to all floor areas can allow more effective hosing - even with significantly less water used. The washing of cars, trucks, and conveyors are normally done with suitable proximity, but floors, tanks and enclosures are typically cleaned from long distances.

Properly specified flow nozzles There is a significant opportunity for saving water with appropriately selected spray nozzles, as these become more common in smaller businesses. The use of open hoses is common in hospitality and smaller commercial

industries. This is usually relatively ineffective and wasteful , while nozzles would allow faster, better and more efficient cleani ng. One key barrier is the selection of appropriate nozzles, as there are a large number of patterns orifice sizes and types - affecting flowrate and practicality. For light wetting of glass and vehicle rinsing, a wide light spray is most effective. For heavy solid waste a straight and powerful jet is req uired. Some products provide a variable spray pattern, and this was found to be a common reason for acceptance by site operators. This is attributed to the fact that many small businesses use the same hose for cleaning a variety of surfaces (such as in a mechanic's workshop).

Consideration for surfaces The selection of floor surfaces was found to make a significant difference to the cleaning conducted on the site. Floors designed to provide grip when wet are particularly difficult to clean. In most cases , a large amount of water wi ll be required to flood and 'float' debris away. Most attempts to use normal


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blasting force wi ll encourage waste to grip t he floor and inconven iently break up into smaller pieces. More careful placement of high-traction surfaces and drains can therefore lead to improved cleaning efficiency. On sites with rough floors al ready installed, dry blowing , close proximity and scrubbing tools are all recommended to clean more efficiently than water 'f looding'.

Managing personal impressions Though many site users were found to have an in -built scepticism regarding lower flow devices, it was noted that this was often overcome if they were ab le to test a device in their own workplace. The majority of users noting a lower f low going to drain are uneasy about swapping from existing fitt ings - for fear of inconvenience and lower time efficiency. Enforcing a trial period was found to allow the psychological barrier to be overcome with many sites developing an acceptance or even a preference for lower flow units withi n days . A c ritical factor is allowing the devices to be tested in the workplace. The average immediate user rating after trying a new low-flow fitti ng in their own workplace was 8.1 out of 10 compared with 5.1 out of 10 for their higher flow exist ing fittings. This shows that many barriers to lower flow are more related to personal impressions and fears t han technical issues - and the opportunity for wider adoption of more efficient devices exists. Ecolab through its Water Care Services is providing a total system approach that begins when water enters the plant, continues at each point of use and then ensures that any water leaving the plant meets local regulations. Water Care Services has been providing innovative solutions in the Australasian Market Place since the 1960's, and is one of Australia's leading water management solution providers. Water Care Services has strategically based its Territory Managers across Australia and New Zealand to ensure the continued delivery of innovative solutions.

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100 FEBRUARY 2010 water

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Disclaimer and Future Development There is still much to be learned about the efficiency of cleaning - flow data is currently only analysed on a small scale as part of studies with other focus areas, and this paper has only touched on the psychological elements, variations between sites within industries, and applicability of new t echnology. There are also considerations for the impact of the use of hot water and pumps on energy use, and the downstream health and wastewater impacts of chemicals and solids loading. The further development of these specific areas is expected to generate more cost effective opportunities for reducing resource use while maintaining and improving hygiene.

Conclusion The consideration of water efficiency in cleaning remains a relatively new concept - particularly in the approach t o cleaning practices across different industries. It has been possible to identify some general opportunities from flow and survey data in a range of workplac es. The further development of these and other opportun ities identified (as water used for cleaning starts to be accurately measured) have the potential to significantly reduce water on a variety of sites.

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The Author Adam Jones (emai l ajones@wbmpl.com .au), an envi ronmental engineer, spent four years with the NSW Government Architects Office before joining the global com pany BMT WBM Pty Ltd in 2008. He has managed and assisted in more t han 100 water efficiency audits through NSW, developed and managed ro llout of commercial pilot programs for Sydney Water, and assisted with design of innovative water treatment and reuse works.

technical features


~ ref ereed pape r

energy efficiency

SYDNEY'S WATER AND ENERGY EFFICIENCY BALANCE P Holt, D Lee, M Ferguson, M Daw son, G Walgenwitz Abstract The emergence of alternative water sources (e.g. desalination, recycled water) and energy sources (e.g. cogeneration, trigeneration, renewables), has significantly increased the complexity of the inter-relationship between energy and water. Th is has required planners to shift t owards integrated and innovative energy and water efficiency solutions. To achieve integrated solutions, planners need to apply systems thi nking. This may involve considering energy and water use both withi n the traditional boundary (i.e. withi n the transport and treatment system) and its interactions with the broader system (i.e. the community).

This paper reviews Sydney Water's portfolio of energy savings and nontraditional power generation. Future efficiency programs wi ll need to consider the balance between energy and water to ensure that cost-effective and sustainable solutions can be delivered. This wi ll become increasingly important with the introduction of the Carbon Pollution Reduction Scheme and the need to fully account for carbon costs.

A combined view to ensure energy and water efficiencies are optimised.

Introduction Water and energy are underlying resources that support communities and economic activity. Increased population and economic growth have driven an increased demand for water and energy. This increased demand is occurring, at times, with prolonged drought periods when limited water resources are available resu lting in stressed water availability for customers including the energy generation sector. Efficient resource use is essential t o managing the challenges of climate change and resource constraints. This has resulted in planners developing integrated and innovative energy and water efficiency solutions.

Dematec Water


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energy efficiency The urban water cycle system is complex, as is the energy sector. The numerous interactions between these systems create an additional layer of complexity.

Systems thinking

environmental

stressors • Climate change • Resource use • Land use

• develop and implement an effective energy and carbon management program including purchase and sale of electricity, energy conservation and efficiency, as well as energy monitoring and reporting • manage Sydney Water's portfolio of viable renewable energy generation projects. The strategy

Figure 1. Systems approach to water and energy efficiency.

To achieve integrated solutions, water authorities need to apply systems thi nking. Figure 1 presents a concentric model of the urban water and energy system and its relationship with ecosystem, society and technology domains. The urban water and energy systems are a sub-set of the built environment within the overall ecosystem. Applying a concentric model of the environment, society and technology to urban water management provides an explicit understanding of limits. As we approach biophysical limits, urban systems (both water and energy) are required to operate within these limits or change so significantly that limits are no longer evident. Water and energy efficiency are key to managing our resources within these limits. Clearly numerous interactions occur between the community, environment and technology elements. Our focus is only on the water and energy elements of the system.

Learning from nature Nature provides a model for com plex systems that have proven resilient to change. Ecosystems are complex, with a multitude of individual components working synergistically. By examining natural ecosystems, insights can be attained and many of the attributes transferred to water management. For an ecosystem t o operate effectively and efficiently the individual components must be able to communicate efficiently to manage material, energy and waste flows (Mitchell and Campbell, 2004). Inherent to the robust 'operation' of most ecosyst ems is the ability to adapt to change. Translating these attributes provides direction in the creation of sustainable water systems.

102 FEBRUARY 2010 water

The objectives of the partnership are to:

Interaction between water and energy systems

Our approach is to examine energy and water resource efficiency by learning from nature, through the application of systems thinking and life cycle thinking to the water and energy efficiency interaction.

refereed paper

In order to create a sustainable water system that is resilient, it is desirable that the attributes and characteristics of the system are analogous to those in the natural ecosystem. These include: • focus on water service provision through efficient end use behaviour (rather than just supplying water) e.g. water demand management programs. • diversity of wat er sources applied on a 'fit for purpose' basis e.g. investment in water recycled water supplies. • flexibility in infrastructure to adapt to changing conditions e.g. the ability t o upgrade treatment technologies or increase transfer system capacities.

Application to Sydney Water The systems thinking approach requires multiple initiatives to address complex systems. Sydney Water's approach has been achieved by: • water efficiency as a key element in Sydney Water's strategy for residential and business customers • introduction of a diversity of water sources through desalination and water recycling to augment runoff stored in dams • dual pipe reticulation schemes such as Rouse Hill and Newi ngton developments.

Energy Partnership Sydney Water recognised energy as a key component in its business agenda. The drive to improve cost effective delivery of water services aligned with Sydney Water's business approach. In 2002, a 10-year strategic Energy Partnering Relationship Agreement was formalised between Sydney Water, Energetics and Worley Parsons t o achieve Sydney Water' s energy goals.

The energy partners - Sydney Water, Energetics, Worley Parsons have: • Developed an Energy Management Plan 2004-05 to 2009-10 outlining broad strategies to achieve Sydney Water's energy goals • Prepared a detailed proposal for the tech nical and commerc ial implementation of renewab le power projects capable of providing almost 20% of Sydney Water's current electricity needs, reducing greenhouse gas emissions by 80 000 tonnes per year and providing attractive financial retu rns • Developed an energy efficiency strategy capable of saving a further 10% of energy consumption and greenhouse emissions and up to 15% on energy costs • Implemented a corporate strategy to maximise the benefit of the NSW Greenhouse Gas Abatement Scheme. The outcomes

The Sydney Wat er Energy Partnering Relationship has demonstrated the ability of the partners to form a single effective team with aligned objectives drawing on the respective strengths of each of the parties to deliver significant value. To date, the Energy Partnership has completed a range of projects, which have resulted in multi-million dollar oneoff savings as well as recurrent savings. Whilst the strategy was initially established to drive cost effective business solutions, its relevance and applicabi lity has elevated due t o the growth in a low carbon economy. Large scale implementation of cogeneration

Th e Energy Partnership has eleven cogeneration plants in operation or in planning at Sydney Water wastewater treatment and water filtration facilities.

technical features


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~ refereed paper

energy efficiency Cogeneration captures biogas, mainly in the form of methane, a by-product from the wastewater treatment process, and converts it to electricity using combustion technology. These biogas plants are located at North Head, Bondi, Glenfield, Liverpool, Warriewood and Wollongong sewage treatment plants. In addition to this, Sydney Water has three hydroelectric generation plants at North Head Sewage Treatment Plant and Woronora and Prospect water filtration plants. The hydroelectric plants capture energy generated by the flow of water or wastewater within the treatment system. The cogeneration plants will produce approximately 20% of the total direct energy requirements of the water and wastewater treatment plants.

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The plant, set to be operational in summer 2009-10, will be powered using 67 wind power turbines at a newly constructed wind farm at Bungendore, NSW. Power from the wind farm will be supplied directly to the east coast electricity grid from which the desalination plant will draw its power.

Water Efficiency Programs Water efficiency programs provide the link between water and energy efficiencies. Outside the water authority's boundary, Flower et al (2007) reveals that the majority of energy usage within urban water systems is within the control of

104 FEBRUARY 201 0 water

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Desalination

The desalination plant relies on reverse osmosis technology, which is highly energy dependent. As part of the planning process, energy requirements and potential energy sources were identified and assessed. It was determined that all of the plant's energy requirements would be met by renewable energy sources.

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Now in addition to these larger scale energy reduction type projects, smaller scale projects are starting to consider the water-energy balance, such as Sydney Water's Every Droup Counts business program.

Sydney's Desalination Project aims to secure Sydney's water supply against the effects of climate change, population growth and drought. Initially, the desalination plant will be capable of providing an additional 250 MUd to Sydney Water's customers. This is equivalent to 15% of Sydney's water demand. The plant design allows for future upgrade to a capacity of S00M U d when required.

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II Figure 2. The closed loop system at Ralph St commercial laundry reclaims water for reuse, cuts energy use, and reduces compliance risk.

end-users of water (i.e. on-site water heating). Sydney Water has an extensive water reduction program focusing on both residential and business customers. These programs have not only resulted in water savings but have also resulted in energy savings. We demonstrate the realisation of these water and energy efficiencies through selected case studies in both the business and residential sectors.

Water efficiency programs - business programs Sydney Water's Every Drop Count's (EDC) program uses a partnership approach to drive water efficiency with large water users. To date, the business program has in 400 participants with 80MUd of savings identified and actual savings of about 40MUd of water. These savings have been achieved by embedding continuous improvement process for water management and close relationship with the client. In addition to improved water management at these business sites, the program may also deliver significant energy savings, if hot water is used.

Case Study - Ralph Street Laundry Ralph Street Laundry operated by the Four Seasons Hotels and Resorts Group uses significant amounts of hot and cold water in its continuous batch washers (CBWs) and washer extractors. Operations Manager, Owen Guarin has holistically managed water and energy to the greatest efficiency possible using typical equipment and technologies. The EDC program highlighted the potential for greater control of the wash program on the CBWs to reduce water use and the associated energy required to heat the water. In addition to this, the steam system feeding t he ironers and CBWs has been modified to be a closed loop (refer to Figure 2). All available condensate is returned to the boiler, saving water and energy as the returned water is hot. Heat from the wash wastewater is transferred to the incoming mains water that is used for the rinse cycle via a heat exchanger. The heat exchanger minimises trade waste compliance risk because hot water is no longer discharged to the sewer. Under the laundry's agreement with

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energy efficiency Sydney Water, wastewater cannot be hotter than 38°C. Working with businesses in this way, Sydney Water demonstrat ed an effective business engagement approach that results in both water and energy efficiency.

Water Efficiency Programs Residential Sydney Water implements a number of water efficiency programs targeted at residential water use. Three of these programs, WaterFix, DIY Water Saving Kits and the Washing Machine Rebate, also consider the potential for energy savings not only water savings. Wat erFix aims to increase the number of homes with water efficient showerheads, toilets and taps. This is achieved through a registered plumber installing 3 star rated showerheads, tap flow regulators, toilet cistern flush arrestors in existing single flush toilets and repairing minor leaks. Since it began in 2000, Sydney Water has provided this service in 474,534 homes, approximately 29% of all homes in Sydney Water's area of operations. It is

~ refereed paper

estimated that this equates to water savings of 9,918 MUyear at the end of 2008-09.

32 kWhr. Hence, a typical WaterFix or DIY retrofit may reduce household energy consumption by 480 kWhr each year.

The DIY Water Saving Kit program targets the same water end uses as the WaterFix program, but it relies on homeowners installing the water saving devices themselves. Sydney Water has distributed 204,471 DIY kits since 2005. At the end of 2008-09, the water savings from the program are estimated to be around 776 MUyear.

Future Trends

Sydney Water also offers a $150 rebate for the purchase of a water efficient washing machine. Initially 'water efficient' referred to a wash ing machine rated at 4 star or above (2006 - 2008); however this changed to 4.5 star or above in August 2008. Since the beginning of the rebate program in 2006, 157,599 rebates have been paid to households, equating to water savings of approximately 3,056 MUyear. Consideration of energy savings from these programs focuses on the volume of hot water saved. For every kilolitre of hot water saved by a household, the energy saving is estimated to be approximately

Sydney Water is currently working to improve its understanding of the water and energy relationship in an operational context, including the sourcing, treatment and transfer of water and wastewater. In addition to this, Sydney Water is investigating the potential role energy will play in the continued development of residential and business wat er efficiency programs. As opportunities for improving energy use arise, these opportunities are being delivered if they fit into broader sustainable decision-making, ensuring optimal outcomes for the commun ity, business and environment. In the future , we will be transitioni ng to a low carbon economy, energy prices will rise and the demands on our existing system further pressured through increased population and the impact of climate change. Efficient resource management is essential to ensure a secure and reliable wat er service is provided to the community.

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Advanced tec hnolo gy enabled the Ap ollo 11 mission to be the fir st manned spacecraft to land on the Moon. On a much sm aller yet still impor tant scale, the wo rld 's first submersible sewage pump dr iven by a premium-effici en cy motor launched by ABS is a giant step for wastewater handling. The ABS EffeX range of submersible sewage pumps offers you compliance wit h forthcoming legislation and the perform ance benefit s of:

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~ refereed paper

energy efficiency

More recently, Sydney Water has implemented an extensive capital works program to reduce demands on traditional energy resources. It has also reduced energy demands through the delivery of water efficiency programs in homes and businesses.

The Authors

the Metropolitan Water Plan. Dennis Lee is a Water Efficiency Specialist within Sydney Water's Every Drop Count's Business team. This team aims to assist Business' to save water through behaviour, equipment and/or process modification.

Learning from the programs, Sydney Water's focus is increasingly to examine jointly the water and energy implications of a given program or piece of infrastructure. This com bined view will ensure energy and water efficiencies are optimised and resources are directed to programs that achieve broad efficiency goals.

Dr Peter Holt (email: Peter.holt@ energetics.com.au) and Giles Walgenwitz are Pri ncipal Consultants with Energetics Pty Ltd, a specialist management consultancy in the business of climate change. Matthew Ferguson and Marcia Dawson are both part of Sydney Water's Sustainability Division, Strategic Directions team. Matthew is a Technical Advisor with the Product & Servicing Strategy team that provide guidance in the long-term planning of Sydney Water's core water, wastewater, stormwater and related strategic products and services infrastructure. Marcia is a Demand Analyst for the Demand Strategies team. This team review water savings from Sydney Water's water efficiency programs, forecast Sydney's long-term water demand and provide input into a number of strategic planning documents, such as

Bibliography

Sydney Water's experience provides a model for other water authorities to apply in a low carbon economy. Future research will predominately focus on a better understanding of Sydney Water's energy profile and the investigation of lower carbon servicing strategies.

Acknowledgment Sydney Water and Worley Parsons as Energy Partners.

Beck, M. B . (2005). Vulnerability of wat er quality is intensively developing urban watersheds, Environmental Modelling and Software, 20, 381 - 400 .. Flower, D.J .M. , M itchell, V.G., Codner, G.P. 2007. Urban Water Systems: Drivers of Climat e Change? Rainwater & Urban Design 2007, Joint 13th International Rainwater Catchment Systems Conference and the 5th International Water Sensitive Urban Design Conference, Sydney, Australia, 21-23 August, 2007. Jeffrey, P., R. Seaton, S. Parsons, T. Stephenson, B. J efferson (1999). Exploring water recycling options for urban environments: a m ultic riteria modelling approach, Urban Water 1, 187 - 200. Mitchell, C. and S. Campbell (2004). Synergy in the City: making the sum of the parts more than the whole, Second IWA Leading-Edge Sustainability Conference Proceedings, Sydney 8-10 Novem ber. Perdan, S. (2004). Introduction to Sustainable Development. In: Sustainable development in Practice, A. Azapagic, S. Perdan, R. Cliff (Eds.), John Wiley & Sons, West Sussex, pp.329.

Groundwater monitoring for Diverse environments CTD-Diver* is a multi-parameter datalogger ideal for applications in water resources, mining, remediation, and coastal zone aquifer management. Designed for corrosive and high salinity conditions, environmental professionals rely on CTD-Diver to get accurate results. • • • •

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climate change impacts

MONITORING AUSTRALIA'S WATER RESOURCES A van Dijk, R Lemon - CSIRO's Water for a Healthy Country Flagship Water scarcity is a major national challenge. Timely and accurate water resources information is a vital step to address t his challenge. CSIRO's Water for a Healthy Country Flagship and the Bureau of Meteorology (Bureau) are developing systems to monitor water resources availability across the nation. These systems combine the strengths of field measurement, satellite observations and hydrological models. The systems produce daily precipitation and evapotranspiration information of unprecedented quality and detail. These products are combined in a wat er resources assessment modelling system to provide co mprehensive and consistent estimates of the water balance from continental to sub catchment scale. This information w ill underpi n the Bureau's annual National Water Account and regular water resources assessments, and also provide val uable and timely information to water management practitioners, policy makers and researchers.

Murtho floodplain, near Renmark, South Australia

(Photographer: Ms

Tanya Doody).

Protecting Water Security Prolonged low rainfall in parts of Australia has exposed the lack of water balance information req uired for timely response and adaptive water resources management. The water scarcity currently being experienced has highlighted the tension over equitable transferable water resources for example, between upstream users and downstream users, between urban and rural users, and between irrigation and the environment. Climate change predictions suggest that water scarcity may represent a new hydrological reality for Australia. Federal and State governments are reforming water management across the country to deal with these chal lenges. A prerequisite for adaptive management is good baseline information and an ability to continuously monitor the impact of actions. Water resource information is collected and held by over 200 organisations across Australia, making it difficult to get an accurate and up-to-date insight into the availability and use of Australia's water resources and to accurately forecast water availability. This situation impedes effective water resources management. Australian governments are responding with programs to provide up-to-date, detailed and accurate information about the generation and use of water resources.

Bureau's New Water Resources Information Services With the introduction of the Commonwealth Water Act 2007 the Bureau is now required to gather and make available water information from all sources across Australia. The Bureau's functions have also expanded to include analysing, managing and disseminating Australia's water resource information. This enables all water resource information to be combined in such

New observation system to assess water availability and use. 110 FEBRUARY 2010 water

a way that it provides a comprehensive view of Australia's water resources. This information is essential for sound decision-making by governments, business and the community. The Bureau's new statutory functions include providing a yearly National Water Account; regular and occasional water resources assessments that interpret current water availability and trends in a historical context; and forecasts of water availability over days to decades.

Developing the Water Information Systems CSIRO researchers have been assisting the Bureau to transform water resource information by delivering new science and tech nology needed to produce value-added water information products and services. CSIRO's Water for a Healthy Country Flagship and the Bureau have established a water information research and development alliance (the Alliance) t o deliver most of this innovation. This Alliance is a strategic investment of $50 million over five years. More than 40 CSIRO researchers are focussing their research efforts on data interoperability (the compatibi lity of different data systems), earth observation, hydrologic modelling, water accounting, water resources assessment and water forecasting. A key activity of the Alliance is developing the technology that will enable the Bureau to provide water resou rces assessments and water accounts to Australian governments, businesses and people. These products need to have sufficient local detail, accuracy and currency, and must be able t o be produced on demand in a robust and transparent manner. This is achieved by objectively testing the performance of different computer models that describe parts of the water cycle and then combi ning the appropriate models in an integrated way within a flexible model-data syst em.

technical features


climate change impacts Model-data Fusion: the Science of Combining Information Hydrological models capture our knowledge of the processes that drive the water cycle. They can provide full water balance information, but without observations are only mental constructs that do not describe reality well . Over many decades weather forecasting has dramatically improved because of the use of local measurements and satellite observations in operational systems. Water resources observation systems can equally benefit from better use of observations. In Australia, the hydrometric measurement network (precipitation , streamflow, diversions, groundwater pressure) is generally sparse. Therefore remotely sensed observations play a crucial role alongside on-ground measurements. Remote sensing observations are obtained by satellites or by so-called proximal remote sensing instruments (for example, precipitation radar or airborne surveys). They provide information at high resolution over large areas. Satellite instruments exist that passively measure reflected sunlight and emitted radiation in the thermal infrared, microwave, and radioactive wavelengths; actively emit and receive reflected radar frequency radiation; or measure variation in the Earths' gravitational field. These observations provide a wealth of information on surface and atmosphere conditions. Generally, on-ground observations are often sparse; remote sensing often indirect; and biophysical models unconstrained. Model-data fusion avoids those weaknesses by combining all three information sources (Figure 1). Pragmatic choices need to be made on the model-data fusion methods and observations used. These choices are being guided by performance testing, in which the improvement in relevance or accuracy of the water information produced can be quantified.

Figure 2. Schematic of the landscape hydrological model in the current version of the Australian water resources assessment system. also provide valuable and timely information to water management practitioners, policy makers and researchers. The system includes a landscape hydrological model that describes the vegetation and soil water balance (Figure 2). The landscape hydrological model is currently being coupled to models used for river and groundwater resource planning. All components of the system continue to be improved through evaluation against a range of observations. These observations include on-ground measurements by soil moisture sensors, river gauging stations and irrigation diversion metering, and satellite observations of vegetation cover, flooding, soil moisture, precipitation, evaporation and groundwater dynamics. The system is capable of providing regular updates on soil water and groundwater storage, generation of streamflow, vegetation water use and other components of the water balance.

What Can it Tell Us? • How much water has been generated as streamflow? • How much water is used where? • How much water is in store? • How does this compare with the past? • Is a trend or shift emerging? • How can we expect water availability to develop?

Figure 1. The water resources observation system combines the benefits of on-ground measurements, satellite observation and biophysical models.

• What are the observed impacts of extractions, land use, farm dams and bushfires on water security and the environment?

Water Scarcity Started 15 Years Ago The First Australian Water Resources Assessment System A prototype Australian water resources assessment system is being evaluated by the Bureau. All information will be generated daily and will have both national coverage and local detail. This system will underpin the Bureau's annual National Water Account and regu lar water resources assessments, and

112 FEBRUARY 2010 water

The first findings from the water resources assessment system have already provided new insights into the recent history of Australia's water resources. The monitoring system has also enabled researchers to examine the archive of data to look at earlier signals of water scarcity currently being experienced in south-eastern Australia. It shows that the water scarcity being currently experienced had its early beginnings 15 years ago when south-eastern Australia

technical features


climate change impacts

total atorage trend (1980-2008) High 3

''81

-100MIA!tl2

Low . -3

Figure 3. Left: Cumulative streamflow generation for the year 2009/10 to date (1 July to 4 November 2009) expressed as the difference compared to average 1980-2009 conditions for the same period. Right: The long-term trend in total water availability in soil and groundwater between 1980 and 2008. Red areas indicate declining trends; blue areas increasing trends.

entered a relatively dry period, causing lower inflows into the large reservoirs (Figure 3). This period has seen reduced water availability in southeastern Australia and increases in northern Australia. Patterns of water balance (and land cover) changes in space and time can be linked to c limate drivers, such as the El Nino Southern Oscillation and Indian Ocean Dipole. More localised effects on the water cycle from human and natural disturbance events such as land clearing and bush fires could also be detected. Figure 4 shows that the time period on which much of our current water planning and expectation in south-eastern Australia is based (1950s-1980s) was generally a relatively wet period. It was during this wet period that Australia started capturing river flows in large reservoirs for growing cities and irrigated agriculture.

40 ,000

If Australia had the observation system technology previously, the onset of dry conditions could have been detected earlier. The information provided by the system will support planning water supply infrastructure and use in the future. For example, the system shows that the catchments supplying the large water reservoirs in south-eastern Australia are still dry and groundwater stores low, suggesting that even one or two good precipitation years may not return good inflows into the dams. Insights like these should help authorities and individuals to plan accordingly.

The Need for Better Data

It appears that we have become over-reliant on what now looks like 'bonus' precipitation during the 1950s-1980s. Drier and warmer cond itions also mean that crops require more

50,000

water to grow, and more water is lost to evaporation from storages. The water resources assessment system shows that winter soil moisture now tends to be lower over large parts of south-eastern Australia than it was in the past, due to reduced precipitation and increased evaporation.

The Alliance is building systems to monit or water resources availability across the nation. These systems combine the strengths of river measurement gauging and water metering, satellite observations and ,----------------------------, hydrological models (Figure 1). The systems CII total system Inflows (10-y a...,rage) produce information of unprecedented quality Irrigation use about: -

dam storage capacity

â&#x20AC;˘ precipitation â&#x20AC;˘ evapotranspiration

30,000

3'

"

These products are combined in a water resources assessment modelling system to provide comprehensive and consistent estimates of the water balance from continental to small catch ment scale.

20,000

10,000

a) Better precipitation data 1907

1917

1927

1937

1947

1957

1967

1977

1987

1997

2007

Figure 4. Time series showing the patterns in total Murray-Darling Basin system inflows over time (shown as 10-year averages to remove noise), as well as the increase of maximum storage capacity in public and private dam storage, and irrigation water use (data from the CSIRO Murray-Darling Basin Sustainable Yields project). 114 FEBRUARY 2010

water

High quality precipitation estimates, with adequate spatial coverage, are essential for accurate water balance modelling, for several reasons. For example, river flow is not measured in many cat ch ments and therefore needs to be estimated from precipitation. Similarly,

technical features


climate change impacts b) Better evapotranspiration data

groundwater recharge needs to be estimated from prec ipitation. At present no precipitation data exists with the resolution and accuracy that fully meet s t he needs for water resou rces assessment and forec asting. The precipitat ion gauging network is very sparse in parts of Austral ia (Figure 5, left), where the current knowledge of precipitation is highly uncertain. Satellite precipitat ion observations provide valuable additional information (Figure 5, right). Over t he past year, CSIRO researcher Dr Luigi Renzu llo (pict ured) and his team prod uced a blended precipitation product by developing a new met hod to exploit the strengths of t he two data sources: t he point accuracy of the gauge observations, and the comp lete coverage of the sat ellite est imates. The blended precipitation prod uct is being compared w ith existi ng dat a sets to evaluate the accuracy of t he new prod uct, and is scheduled for implementation alongside current Bureau operations for further extensive testing and evaluation. Research cont inues into the development of methods t hat accommodate addit ional spatial variables (e.g. elevation) and precipitat ion informat ion sources such as precipitation forecasts and observat ions fro m the on- gro und precipitat ion radar network.

Water use across Austral ia is cu rrently poorly known. In many irrigation areas metering of water takes occurs infrequently, and wetland wat er use can only be inferred from streamflow measurements. Evapotranspiration is the sum of evaporat ion from water and soil and plant water use. Like precipitation, higher resolution and more accu rate spatial information on evapotranspiration is essential for better water management, especially given Australia's large ungauged areas and high evaporation rates. The information needs to be produced for the entire continent, ideally at field scale and at a weekly or better timestep. Currently available water use estimation techn iques include water balance models, algorithms driven by sat ellite observat ions, and combinations of the t wo approaches. Generally water balance models are more accurate in humid areas and areas w here local precipitation is the only source of water use. Satellite methods t hat rely on land surface temperature or wetness are more reliable where river flows and groundwater are being used, for example in wetlands and irrigat ed areas. Each technique has strengths and weaknesses , therefore finding the best way of combining these is the key to producing the information required. A CSIRO team led by Dr Edward King (pictured) is assessing evapot ranspiration data sets prod uced by a number of alternative techniques. Their performance is being assessed both against independent data sets, such as catchment-scale streamflow measurements and direct field measurements of evapotranspiration , and against one anot her, to analyse t heir relative strengths and weaknesses to provide insight into how they can most effectively be combined . A prototype operational system to routinely prepare actual evapotranspiration wi ll be developed based on the outcomes of the evaluat ion (Figures 6a, b).

Closing the Water Balance Accounting for all storage, transferred and fluxes of water over areas ranging from small catchments to the continent, with adequate accuracy, has not yet been achieved in Aust ralia. Better information about precipitat ion and evapotranspiration is a prerequisite to achieving this.

Dr Edward King (left) and Dr Luigi Renzullo.

Gauges per 0.25° cell

oo

0 1

0 2 â&#x20AC;˘

â&#x20AC;˘

3-4 5-25 mm/day

Figure 5. Left: The distribution of precipitation gauges across Australia. Right: an example of the blended gauge-satellite precipitation product for 5 January 2005.

water FEBRUARY 2010 1 15


climate change impacts Much progress has been made in the weather and climate modelling community. Land surface models that are used in weather and climate modelling use a wider range of observations and consider observational errors better than hydrological models. However these models operate on spatial scales that are too coarse and do not describe hydrological processes very well.

Dr Albert van Dijk.

A CSIRO team led by Dr Albert van Dijk (pictured) is developing the world's first integrated system for detailed water balance analysis at continental to sub-catchment sc ale. The team assesses the performance of the variety of existing models that describe parts of the water cycle, and integrates the best methods within a flexible software system. Performance tests are applied to assess the most appropriate model structure and complexity, and to allow objective, ongoing improvement. Mathematical model-data fusion methods (see Figure 1) are being developed to bring the model and data into agreement. This requires comprehensive consideration of all errors, in the models as well as in the observations. It allows the wat er balance to be estimated with greater detail and accuracy and with quantified uncertai nty.

Figure 6a. Water balance for Australia averaged over the period 2001-2006, produced by combining precipitation and satellite evapotranspiration products. In blue areas precipitation exceeds water use for this period, in brown areas evapotranspiration exceeds precipitation (e.g. irrigation areas, floodplains and wetlands).

New ways are developed to present the generated data in insightful ways , for example through data summary techniques (e.g. trend analysis, anomaly analysis) and appropriate reporti ng of data uncertainty.

Looking Ahead Over the coming years, further research will enhance and expand the system for a wider range of uses. Some of the enhancements include more complete tracking of river and groundwater flows in some of Australia's complex water systems and combining the observing system with seasonal climate outlooks. New information developed may include vegetation growth (of importance for example to predict crop yields) and information on carbon uptake across the continent. This information, and the insights and expectations that can be derived from it, wi ll help Australia respond to its variable climate.

Acknowledgment A component of this article has been reprinted with permission from Farming Ahead.

The Authors Murray River (near Murray Bridge), South Australia. (Photographer: Ms Tanya Doody).

116 FEBRUARY 2010 water

Dr Albert van Dijk is with the Commonwealth Scientific and Industrial

Figure 6b. Water use in part of the Murrumbidgee and Murray Basins, NSW (the red box in Figure 6a) for February 2002. Blue colours indicate high water use.

Research Organisation (CSIRO) in Canberra, Australia. He leads a team of around 30 scientists and engineers to develop water resources assessment and accounting technology, through the water information research and development alliance between CSIRO's Water for a Healthy Country Flagship and the Bureau of Meteorology Water Division. Ms Roz Lemon is a Science Communicator with CSIRO in Canberra, Australia. She delivers communication services to CSIRO's Water for a Healthy Country Flagship and CSIRO's Land and Water Division. Email: Roz.Lemon@csiro.au.

technical features


climate change impacts

[sl

refereed p a per

QUANTIFYING CLIMATE CHANGE IMPACTS ON THE URBAN WATER CYCLE J Stanmore, R lyadurai

-

Abstract Projected climate change has t he potential to impact not only on water availability, but also t he performance of urban water systems. Th is paper outlines tech niques to quantify the impacts of p rojected climate change on the int egrated urban water cycle and the subsequent management risks, responses, challenges and opportunities for local water utilities (LWU). The results of applying t hese techniques to t wo LWU in New South Wales are reported in this paper.

.,,_ . . ... ,

Introduction Qualitative descriptions of expected climate change impacts on water resource management have been well documented both in Australia and abroad (IPCC 2008). Within t he urban water sector, these impacts include increased water demands, frequency of urban stormwater flooding, frequency of sewer overflows and red uced potent ial for harvesting from alternative local water sources (rainwater tanks, stormwater harvesting and sewer mining). Th is paper outlines techniques to quantify the impacts of projected climate change on the urban water cycle and the subsequent management of risks, responses, challenges and opportunities for local water utilities (LWU). These tech niques are presented in t he co ntext of integrated water cycle management (IWCM).

Methodology Defining the urban water cycle The components of the urban water cycle that are impacted by cl imate change (red text and arrows) are outlined in Figure 1. This paper explicitly deals with the impacts of climate change on water demands, sewer flows and stormwater runoff, while Studies of the impacts on other elements of the urban water cycle are in progress.

R8UN(vla NWlr n1M'lg)

-

......

Figure 1. Components of the Urban Water Cycle Impacted by Climate Change. town. The climatic variables in Table 1 (and al l further results in this paper) relevant to LWU1 relate to the coastal cli mat ic zone (the most heavily popu lated).

Climate change in Australia Projected regional cli matic variables (CSIRO 2007) were utilised to quantify future changes in the urban water cycle. The best estimates of the Medium Emission (A1 B) Scenario projections (incl uding seasonal variation) for temperat ure, precipitation and potential evapotranspiration were then app lied t o local climatic data of the study area.

It is important to note that t he projected impact of climate change on raw water sou rces (e.g. catchment hydrology) has not been considered as part of this paper.

St udy areas The techniques for quantifying the impacts of climate change have been applied t o two distinct NSW LWU (LWU1 and LWU2). Table 1 summarises some key demographic and climatic parameters for the study areas while Figure 2 shows the NSW regions where the LWU are locat ed. Note that LWU1 was spread across two climatic zones while LWU2 is an inland

Murray Regk)n (LWU2)

Il Not only on water availability, but also the performance of urban water systems. 11 8 FEBRUARY 2010 water

Figure 2. Location of Study Areas.

technical features


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climate change impacts Table 2 summarises the projected seasonal impact of climat e change on the climatic variables of rainfall, temperature and evapotranspiration (the 3 variables most relevant for the urban water cycle). The numbers in Table 2 represent the percentage increase or decrease for each of the climatic variables due to climate change. The climatic corrections in Table 2 are important for determining t he impact of climatic change on t he natural variability of the historical record. This data is relevant for average year water demand (AYO) and dry year wat er demand (DYD). AYO is relevant for determining annual recurrent costs wh ile DYD is used in the design of water supply headworks. With respect to extreme cl imatic occurrences, the literature examines the impacts of climate change on low frequency events e.g. floods, bushfire and d roughts (Hennessy et al. 2004, CSIRO 2007). Table 3 shows the published impact of climate change on extreme daily rainfall events in the st udy area. Such infrequent events are not necessarily applicable for projecting the impacts of climatic extreme on the urban water cycle. For example, urban wat er cycle managers would not plan to manage overflows from sewerage networks at 1 % AEP rainfall events as t he majority of their network would most likely be submerged. As such the 2030 2.5% AEP event impact has been applied in this paper. It is noted that the 2050 cl imate change impacts shown in Table 2 and Table 3 are t he result of non-downscaled projections based on a modelling grid size of 175 km 2 (CSIRO, 2007). Downscaling produces high resolution climate change projections at finer spatial and temporal resolutions. This allows for a more detailed assessment of the impact that climate change wi ll have on the intensity, frequency, and duration of rainfall extremes (including flood and drought conditions). Downscaled cl imate impacted time series of a number of climatic variables have been established for NSW based on a modelling grid size of 25 km 2 0Jaze et al. 2008). This downscaled time series data was not available when the results in this paper were produced.

Impact on annual water demands In order to determine relationships between climatic variables and historical water consum ption, time-series modelling of residential end-use

120 FEBRUARY 2010

water

Table 1. Selected Characteristics of the Study Areas. Characteristic

LWU1

LWU2

Permanent Water Supply Population (2008)

13,000

7,300

No. of Population Centres

5

NSW Region

Northern Rivers

Murray

2

1

1,405

404

657

141

2

No. of Water Supply Systems No. of Climatic Zones Annual Rainfall (mm)

Average Dry

1,644

1,863

No. of Days Above 35°C

1.5

32.6

No. of Days Above 40°C

0.3

7.3

Average Annual Evaporation (mm)

Table 2. Impact of Climate Change on Climatic Variables in 2050. Climatic Variable Maximum Day Temperature (% Change)

LWU1

LWU2

Annual

+9.4

Summer

+7.7

+5.5

Autumn

+6.4 +9.1

+7.4

Annual

+9.4 -3.5

+7.4 -3.5

Summer

+0.0

+0.0

Autumn

-3.5

Winter Spring

-7.5

+0.0 -7.5

-7.5

-15.0

Annual

+6.0

+6.0

Summer

+6.0

+3.0

Autumn

+6.0

+6.0

Winter Spring

+6.0

+10.0

+6.0

+3.0

Winter Spring Daily Rainfall (% Change)

Evapotranspiration (% Change)

+7.4

+8.2

Note: The percentages in Table 2 represent the midpoint in the range of impacts

Table 3. Impact of Climate Change on Extreme Daily Rainfall Events. Event Frequency

LWU1

LWU2

% Impact in 2030 (2.5%AEP) 1

-2.5%

+11 .0%

% Impact in 2050 (1.0%AEP)2

-3.0%

+1.5%

% Impact in 2070 (2.5%AEP)1

+7.5%

+7.0%

1 Hennessy 2

et al. 2004

CS/RO, 2007

components is undertaken. A lot-scale climate-driven daily water balance model, wh ich incorporates indoor, evaporative cooler (if appropriate) and garden water use components, is used to estimate consumption for a residential house over a historic climat ic data set. Garden demand estimation is achieved throug h a soil -moisture triggered irrigation function while evaporat ive coolers is also calculated daily based on empirical factors for days when the maximum temperature exceeds 27°C. A detailed explanation of demand generation using the above model can be found in Stanmore et al. (2007).

Through this approach, unit residential AYO and DYD can be established over the modelling period . By applying the climat ic corrections of Table 2, climat e impacted AYD and DYD can be established for the climate-dependant residential end-uses. These lot-scale residential demands can then be aggregated to the reservoir zone scale, climatic zone scale (as was relevant for LWU1) and ultimately to the headworks scale. End use models that match local demographic and water efficient technology profiles complement this process.

technical features


G

climate change impacts Non-residential demand (sp lit across a number of customer categories) is added to the si mulated residential demand based on historical customer b illing records and other relevant parameters (e.g. visitor numbers for tourist categories). Non-residential cl imatedependent end-uses are also identified. The daily si mulation is then compared against historic bu lk records on a monthly basis with suitable corrections made for water rest rictions (if appropriate), water pricing and lot sizes.

Impact on peak day water demands Peak Day Demand (POD) is examined at both a syst em-wide and reservoir zone scale using t he water balance model at the lot-scale. POD is an important parameter in the design of water supply networks as it det ermines the size of water treat ment and distribution infrastructure (up to and includ ing distribution reservoirs). Through spatial

analysis of customer bil ling and demographic records, and matching with historical water production records, unit POD are determined for distinct customer categories at a reservoir zone scale. Further end use analysis al lows for th e determination of climate independent (fixed) and dependent (variable) POD across the customer categories. Using the wat er balance model, ratios are determined between maximum mont h and average day variable demands for non-climate and climate impact ed scenarios. The time-series analysis met hodology was not considered sufficient t o estimate the impacts of cl imate change at a daily time step (see earlier comments with regards to downscal ing). By aggregating t he reservoi r-zone specific unit demands, taking into account t he split of residential and nonresidential con nect ions, non -revenue

Table 4. Impact of Climate Change on Annual Water Demands for a Single Residential Dwelling. Demand Type

End Use

Average Year Demand (kl )

Dry Year Demand (kl)

Non CC Impacted LWU1 LWU2

2050 CC Impacted LWU1 LWU2

Internal

161

148

161

148

External

70

321

82

345

EC

0

40

43

Total

231

509

0 243

536

Internal

161

148

161

148

External

99

397

116

418

EC

0

58

0

63

Total

260

602

277

629

Table 5. Impact of Climate Change on Peak Day Water Demands for a Single Residential Dwelling. End Use Type

Non CC Impacted LWU2 LWU1

2050 CC Impacted LWU1 LWU2

Fixed Variable

0.64

0.66

0.64

0.66

1.85

5.01

2.01

5.29

Total

2.50

5.66

2.64

5.95

Note: Unit PDD are in kl

Average Year

Dry Year

water (NRW) and local demog raph ic parameters, POD is projected across t he relevant planni ng horizon.

Impact on sewer wet-weather flows The impact of wet weather flows on the sewerage network is established by comparing actual and theoretical storm allowances for historic wet -weather events. By linking historical overflow events to rainfall annual exceedance probabilities (AEP), the increased frequency of sewer overflows for individual sewage pumping station (SPS) and gravity catchments can be quantified.

Impact on alternative local water sources The availability of cli mate-change impacted rainwater and stormwater as alternative water sources is quantified t hrough extensive land-use analysis on a stormwater sub-catchment basis. The si m ulation of end-use demand (typically but not limited to urban irrigat ion opportunities) in parallel with sou rce availability allows for a detailed analys is of req uired storage size, expected yield and conseq uent potable water savings.

Results and Discussion Annual water demands Table 4 shows the si mulated impact of climat e change on average year and dry year annual water demands for a si ngle residential dwelling. Table 4 shows t hat although LWU2 exhibits a greater absolute increase in AYO and DVD due to climate change, LWU1 is more severely impacted in terms of percentage increase, especia lly with regards to external demands (17% increase for both average and dry years). This can be explained by t he relatively high rainfal l conditions at LWU1 and the historic response of customer behavio ur to changes in rainfall.

Toilet

99%

93%

99%

91%

T + Washing Machine

88%

86%

62%

Garden

58%

65% 14%

53%

13%

T +WM+ G

52%

15%

47%

14%

It is noted that Table 4 outlines a snapshot of unit residential demand across t he study area for a given household size (HHS), lot size and water efficiency technology profile. When projecting customer category consumption across t he planning horizon , these parameters are varied w ith t ime in order to accurately represent end use demand.

69%

100%

64%

Impact on peak day water demands Table 5 shows t he impact of climate change on variable and total unit residential POD across the study area.

Table 6. Percentage of End Use met by a 5 kl Rainwater Tank for a Residential House. Year Type

refereed p a per

End Use

Toilet

Non CC Impacted LWU2 LWU1

100%

2050 CC Impacted LWU1 LWU2

T + Washing Machine

82%

36%

78%

34%

Garden

49%

13%

44%

9%

T +WM+ G

38%

6%

35%

5%

122 FEBRUARY 2010 wat er

technical features


~ refere e d p ape r

Table 5 shows that lWU1 is again impacted more t han lWU2 (i n percentage increase terms with respect to PDD, especially for variable demands (8.6% lWU1 , 5.6% lWU2). The ratio of maximum month to average day demand is much more susceptible to climate change impacts, again due to the high average rai nfall at lWU1.

climate change impacts

..

70%

I

I -

-

-

-

-

-

_I_ I

-

-

-

-

-

Table 6 shows the compound impact on RWT yield through higher end use demand, reduced rainfall and increased evaporation. Table 6 shows that RWT pl ay an important role as an alternative water sou rce across t he study area. 5 kl RWT installed at a typical residence at lWU1 exhibit yield reductions of 5% and 3% (due to climate change) when trying to meet toilet, washing machine and garden demands during average years and d ry years respectively. Figure 2 shows d iagramatically t he sim ulated impact of c limate change on RWT yield at l WU1 for various RWT size attempting to meet toilet , washing machine and garden demand at a residential house. Figure 3 shows how additional rainwater tank storage is required to negate the impact of cl imate change in terms of meeting residential end uses. Such risks impact on the costs and benefits (from both a customer and utility perspective) of rainwater tank rebate programs.

Cumulative impact at headworks After combin ing the residential and nonresidential demands through the process outli ned above, projections of AYD and DYD at the headworks scale can be

••• - · · · · · · · · · · : - -

-

-

-

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j

I

-

-

-

-

-

-

-

I

- - ~.:.:-::::.,...-·c:··.:.··.:.··~··; - - - - - - I

Impact on rainwater tank yield Table 6 shows the impact of cl imate change on rainwater tank (RWT) yields (5 kl tank) for a number of residential end use scenarios across the st udy area.

-

I I

···t ··· - -:.-··.:..··:..· - l. - I

••• ••

-I -

-

t· 30%

-

-

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-

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--0-lnll rtd (AV)

·· • ··Inland (AY-CC)

--+-1,..nd (DY)

·· + ·• Inland (DY-CC)

-

-

-

- -----------------------+-------' 2()

10 15 Rainwater Tank Slz• (k.L)

25

Figure 3. Percentage of Garden, Toilet and Washing Machine Demand met by RWT at LWU1 . 4'00 , - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ~ ~

--------------- ----------------------

'·""'

-

-

r- -

«" -

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1 500

1,000

-

-

-

-

-

-

-

-

-

-

-

-

-

-

---Traooon.l · Dry Ytar

-+- Ttad.tionel • CC 2050 (.Av y..,.) -+- Tr.Slioo.l • CC 2050 jO!'y YMt)

~

------------~--------------~

Figure 4. Projected Annual and Dry Year Water Demands at LWU1 .

prod uced . Figure 4 shows the projected AYD and DYD at the headworks of l WU 1 together with c limate change impacts. Figure 4 shows that the simulated impact of cl imate change at l WU1 resu lts in increases of 4.7% AY D and

8.9% DYD respectively at t he end of t he p lanning horizon. Furthermore, cl imate change results in the lWU1 extraction licence being exceeded five years earlier (DYD). T hrough projecting climate impacted d emands at the headworks

water

FEBRUARY 2010 123


~ ref e reed p a p e r

climate change impacts scale, t he LWU can plan to adapt to such risks with appropriate lead t imes of action. Through the use of time series modelling on a daily time step, the impact of cl imate change on monthly demands can also be simulated. This is especially important for security of water supply analysis by superimposing demand patterns on the availability of water. Figure 5 shows the impact of climate change on the monthly distribution of DYD at LWU1. Figure 5 shows the significant increases in the January and October components of DYD due to the impact of climate change. The increase in Oct ober is particularly significant as this coincides with the period of highest risk with regard to water availability. Figure 6 shows the projection of POD including the impacts of climate change at the headworks of LWU2. The pot able water syst em at LWU2 consists of two reservoirs and associated distribution systems. Both reservoir zones have their POD increased by 4.5% due to close proximity and relatively small growth rates. At LWU1 however, simulated climate change resulted in a POD increase of 0.4% to 3.7% at the reservoir zone scale depending on the customer category profile, climatic zone and ratio of new to existing dwellings.

Impact on sewer wet-weather flows Using the 2030 2.5%AEP extreme rainfall impacts from Table 3, the impact of climate change on the frequency of known sewer overflow events was determined. Table 7 shows the noncl imate impact ed and climate impacted results for the study area. Table 7 shows that at LWU1, sewer overflows are already occurring more frequently than once a year in some SPS catchments. Consequently, the impact of extreme rainfall event project ions (see Table 3) has little significance at LWU1 . At LWU2 however, known overflows only occur during 16% AEP daily events (5.6 year ARI) or above. This is due to the low rainfall nature of the climatic zone of LWU2. Due to climate change, LWU2 therefore can expect to have a 7% increase in probability of having sewer overflow events in any given year. This process identified SPS augmentation requirement s across a hierarch ical sewerage network under both non-climate impacted and climate impacted scenarios.

124 FEBRUARY 2010 water

,.,.

-

---

--

,.,. C NoCC

,,..

CICC2050

r~ ..

-

1,

.... ... -

-

-

-

-

~

-

-

-

-

... 2%

...

0

A

M

M

0

Figure 5. Impact on Monthly Distribution of Dry Year Water Demand at LWU1.

25

----

M

------ -

----------------- ---- ---------

n -------------------------22

----- ----=-~-~-~-~------------------------ -

------------

18

-

-

-

-

-

17

-

-

-

-

-

16

-

-

-

-

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Headworka Projeetk>n

' - - - - - --

-

HW(CC2050)

- --

-

-

-

-

-

-

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---' -

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-

-

-

15 -1------------ ~ - - - - - - ~ - - - -- ~------l 2005

2010

2 01 5

2025

2020

2030

2035

20<0

Figure 6. Projected Peak Day Water Demand at LWU2. Table 7. Impact of Climate Change on the Frequency of Sewer Overflows. LWU1

LWU2

82.0

62.6 16%

ARI (years)

88% 0.5

%AEP

88%

23%

ARI (years)

0.5

3.9

Climatic Parameter 24 hour rainfall event (mm) Non-CC Impacted 2030 CC Impacted

%AEP

5.6

Table 8. Impact of Climate Change on Annual Stormwater Runoff for a Single Residential Dwelling. Non CC Impacted LWU1 LWU2

Year Type

Average Year (kl)

Dry Year (kl )

2050 CC Impacted LWU2 LWU1

Typical Lot Size (m 2)

750

990

750

990

Existing (No RWT)

595

105

556

95

Existing (5kl RWT)

528

57

488

49

New (5kl RWT)

535

57

494

49

Existing (No RWT)

458

35

398

38 10

441

Existing (5kl RWT)

381

9

New (5kl RWT)

401

10

384

9

technical features


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k

f e:J

-Pi-

!/

f {:2--5


D!]

climate change impacts 20,000 , - - -- - - - - - - - - - - - - - - -- -- - - - - - - - ,

19,000

-

Ulton Runoff (No CC)

-

Ulton Runoff (CC20SO)

-

NabJ<*ised{No CC)

18,000

i

11,.000

refereed paper

Table 8 shows that runoff from a typical residential lot at LWU2 is low, reflecting the low rainfall conditions. As such, the impact of climate change on stormwater runoff at LWU2 , although high in percentage terms , is not significant when considering stormwater as a harvesting source.

0:

~ • 12,000

! 10,000

9 ,000

0,000

+ - - - - - - - - - ~ -~ - - -- - - - - - - - - - - - - - - - <

2000

2005

2015

201 0

2020

2025

2030

2035

2040

2045

20SO

Figure 7. Impact on Average Year Stormwater Runoff from Urban Areas at LWU1.

Impact on stormwater runoff Table 8 shows the modelled unit annual stormwater runoff (including the impacts of climate change) for typical residential lots across t he study areas. Stormwater runoff from existing dwellings without

RWT, as well as new and existing dwellings with RWT have been included in Table 8. Such category separation is necessary to quantify the impact on stormwater generation of fitting RWT to new dwellings as well as RWT retrofit programs.

• Potable Water • Remote Well Sites • Booster Stations

In contrast LWU1 exhibits significant reductions in unit stormwater runoff in both average and dry years due to climate change. This is most pronounced in existing dwellings with RWT (i.e. as part of RWT retrofit programs). This can be explained by existing dwellings having less efficient water efficient technology profiles as opposed to new dwellings, coupled with the increased drawdown of RWT under c limatic impacted conditions. New dwellings at LWU1 with a 5 kl RWT have their annual runoff reduced by 7.7% and 4.2% respectively due to climate change. Th is may be seen as a positive or negative depending on particular catchments and management objectives. For example, if stormwater harvesting were an objective than this is a negative factor, however if an objective were to return runoff to pre-urbanised conditions than this is a positive outcome. In order to project stormwater runoff quantities from urban areas to receiving streams, the unit residential results of Table 8, together with an analysis of impervious, pervious irrigated and nonirrigated pervious areas is undertaken on a stormwater sub-catchment basis. Figure 7 shows the projection of average year stormwater runoff from the urban areas within LWU1.

Uncertainty and limitations

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126 FEBRUARY 2010 wat er

It is important to note that the techn iques discussed in this paper have been developed and applied withi n the context of IWCM. IWCM is a scenario based exercise for addressing issues related to the management of the urban water cycle by LWU. As a consequence the quantifying of climate change impacts is only one aspect of the study process, and hence extensive sensitivity analysis within this context is not possible. This notwithstanding, the presented tech niques allow urban water managers to undertake further detailed analysis of climatic impacts as part of more targeted studies. Such studies would allow for all of the climate change impacts on the urban water cycle (red items in Figure 1) to be quantified. The climatic records relied upon for this paper were sourced from SILO. As a consequence, climatic dependent

technical features


····---.-....-..

WA I I:. K.'-U

Water, the liquid of life demands were estimated using the climatic record from 1/1/1970 to present, as evaporation data is often erroneous before this date (DNRME, 2004). This modelling limitation could be overcome by relying on the projected data sets prepared by Vaze et al. 2008.

LWU

Local Wat er Utility

NRW Non-Revenue Water NSW

New South Wales

POD

Peak Day Water Demands

RWT

Rainwater Tank

SPS

Sewage Pumping Stations

COMMERCIAL FIBREGLASS WOUND VESSELS

The Authors

Conclusion The application of the tech niques presented in this paper allow urban water cycle managers to make informed infrastructure decisions taki ng into account the risk of climate change impacts. The elements of the water cycle that are frequently relied upon for decision making include: • AYO {for the evaluation of costs and benefits of water conservation measures); • DYD {for the sizing of headworks infrastructure); • Climate impacted POD and AYD (as a benchmark for identifying water conservation targets); • Climate impacted DYD (as the basis for water licence allocat ion renewal); and • Climate impacted extreme rainfall events (under some scenarios) for the sizing of SPS using storm allowances, providing the necessary flexi bility for future augmentation. Projected climate change has the potential to impact not only on water availability, but also the performance of of all urban water systems. In the absence of reliable projections of future changes in hydrological variables, adaptation process and methods which can be usefully implemented in the absence of accurate projections, such as improved water-use efficiency and water-demand management, offer noregrets options to cope with climate change (Bates et al. 2008).

Nomenclature AEP

Annual Exceedance Probability

ARI

Average Recurrence Interval Average Year Water Demands

AYD

cc

Climate Change

DYD EC

Dry Year Water Demands Evaporative Cooler

HHS Household Size IPCC Intergovernmental Panel on Climate Change IWCM Integrated Water Cycle Management

John Stanmore (email john.stanmore@services. nsw.gov.au) is an environmental engineer with 9 years experience in the areas of integrated water cycle management, climate change adaptation strategies, community consu ltation and water conservation programs. Roshan lyadurai (emai l roshan .iyadurai@services. nsw .gov .au) is a chemical engineer and has extensive experience in integrated water cycle management studies and in the development of water services strategies for NSW towns. Both Roshan and John work as consultants to the water industry with the NSW Department of Services, Technology and Adm inistration (formerly Department of Commerce).

Capable of processing up to 396 m3/hr. Suitable for commercial, industrial, municipal and water treatment applications.

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CARTRIDGE AND BAG FILTERS

References Capable of withstanding up to 600kPa.

Bates, B.C., Z.W. Kundzewicz, S. Wu and J.P. Palutikof, Eds. , 2008. Climate Change and Water. Technical Paper of the Intergovernmental Panel on Climate Change, IPCC Secretariat, Geneva, Switzerland.

Suitable for commercial and water treatment applications.

CSIRO, 2007. Climate Change in Australia Technical Report 2007. DN RME, 2004. New Australian Daily Historical Climate Surfaces Using CLIMARC Summary, Queensland Department of Natural Resources, Mines and Energy, August 2004.

ELECTRONIC COAGULATION

Hennessy, K., Mclnnes,K., Abbs, A. , Jones, R., Bathols, J., Suppiah, R., Ricketts, J., Rafter, T., Collins, D. and Jones, D., 2004. Climate Change in New South Wales - Part 2: Projected changes in climate extremes, CSIRO, November 2004.

Precipitates and coagulates a wide range of contaminants.

IPCC, 2000. Emissions Scenarios. Special Report of the Intergovernmental Panel on Climate Change. Nakicenovic, N. , and R. Swart, Eds. Cambridge University Press.

Suitable for grey water recycling applications.

Stanmore, J. , Renshaw, M. , Blaikie, J. and lyadurai, R. , 2007. Innovation in Demand Profile Estimation for Rural Communities, NSW Department of Commerce, Sydney, NSW, Australia.

Vaze, J., Teng, J ., Post, D. , Chiew, F. , Perraud, J-M. and Kirono, D. , 2008. Future climate and runoff projections (- 2030) for New South Wales and Australian Capital Territory, NSW Department of Water and Energy, Sydney, NSW, Australia.

NSW (Head Office) 02 9898 8686

QLD 07 3299 9900

SA / NT 08 8244 6000

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water source protection feature

CATCHMENT MANAGEMENT FOR DRINKING WATER PROTECTION R Ford The provision of safe drinkin g water is the responsibility of water supply authorities. The Australian public has a high level of confidence in their water supplies and expect the water provided at the tap to be safe to drink at all times and under all conditions, without exception. Any suggestion that the water is contaminated or not suitable for drinking attracts intense media interest and commu nity outrage. This high expectation is backed in most states by legislation specifying stringent quality criteria, which emphasises a catchment-to-tap approach to drinking water quality management. In many situations the catchment is not managed by the water agency with the responsibi lity for treating and distributing drinking water to the public consequently water authorities often have little or no control over the raw material used to produce their final product. As water production is a continuous process it is virtually impossible to recall the final product should routine sampling detect a non compliance. The Australian Drinking Water Guidelines emphasis that pathogens are the greatest risk to public health from a water supply. The consequences of a contamination event caused by pathogens is likely to be catastrophic and in capital cities would impact on the health of literally millions of people. Consequently water authorities must always have as their primary focus their public health responsibility. The requirement to ensure that public health is protected is assured by the provision of multiple barriers to protect water quality. Any one barrier can, and probably will at some point in time, fail. This may be due to a mechanical failure, environmental situation or human error. It is important that there are additional barriers that can maintain water quality and assure the protection of public health when this occurs. It is equally important that there are surveillance programs in place to detect the failure of any barrier and management programs and resources available to immediately ensure restoration. Should routine sampling of the final product detect

128 FEBRUARY 2010 water

contamination it is likely a number of barriers have been allowed to fail and either not detected or the importance of immediate rectification not understood. The first barrier to water quality protection is the protection of source waters. Although most catchments are not under the control of the wat er authority there are many actions that water authorities can and should take to reduce the risk of contamination. Water treatment plants are designed to accept and treat water up to a specified quality. During extreme storm events the ability of the treatment plant to produce safe water may be chal lenged. Unfortunately this is also the time when the highest levels of contaminants and pathogens are likely to be present. Catchment management can reduce the size of the challenge on water treatment plants and consequently reduce the risk of failure. As a secondary benefit protection of source waters will generally also reduce the capital and operating costs associated with treatment. To discuss catchment management in the context of source water protection a number of specialists working in the area from Australia and the United States met for a joint workshop in Hawaii in March 2005. The objective was to workshop the actions water authorities can t ake in catchments, particularly those not under their control, to protect water quality and

document suitable case studies. The workshop was convened jointly by the Australian Water Association and the American Water Works Association. The outcome was to be a "Best Practice" manual on catchment management for source water protection. The workshop examined a range of issues involved in managing catchments and protecting water quality including stakeholder identification and involvement, land use planning, monitoring and surveillance, incident management and available tools and resources. Each area was investigated and case studies prepared. The manual titled Watershed Management for Drinking Water Protection edited by Chris Davis, the then CEO of AWA, has been published and is available from the AWA bookshop. The following articles include a precis of chapters from that manual prepared by members of the Catchment Management Specialist Network of AWA for WATER.

The Catchment Management Specialist Network The Network was formed about 15 years ago at the request of the AWA Board. Bob Ford, then Engineer-in-Chief of the Ballarat Water Board, was asked to be the first convenor. The Network initially distributed irregular newsletters, prepared

technical features


water source protection feature submissions to government and established local convenors in the Eastern States. In late 1990 's the NSW branch held the first AWA catchment management conference in Parramatta which helped establish contacts between the academics and the industry. The AWA Board continued to support the Network and in 2004 Chris Davis was seeking closer ties with the American Water Works Association and approached Bob to see if the Network would be interested in a joint project. These discussions led to the 2005 Hawaii workshop and eventually to the publication of the joint AWA, AWWA manual. The group has organised a number of networking opportunities and in 2009 a major travelling convention involving international speakers in Melbourne, Sydney, Brisbane and Adelaide. In 2008 Bob retired from full time employment and Christobel Ferguson took over the role of convenor with Rob Considine as co-convenor. Bob remained active in the group and other AWA comm ittees and being retired, took on the lead responsibility of coordinating and preparing this series of papers on catchment management for WATER for the Network. The Catchment Management Specialist Network is interested in expanding its interest s and activities to include not just protection of drinking water sources but wider issues of catchment management, its impact on the quality and quantity of water available in the nations waterways and increasing the awareness of state and local government of the value of catchment management. Any AWA members interested in being involved in the Network's activities are invited t o contact any of the authors who are members of the Catchment Management Specialist Network Committee or email networks@awa.asn.au.

Bob Ford

WATER SOURCE PROTECTION FEATURE AUTHORS Nearly all are members of the Catchment Management Specialist Network Committee INTRODUCTION: Bob Ford retired from Central Highlands Water in 2008 after 35 years involvement in the water industry which included a special interest in catchment management. He is still actively involved in AWA and currently a member of the Journal Editorial Committee. bob.ford@ncable.net.au RISK: Rob Considine leads Melbourne Water's drinking water quality planning team. Having been involved in drinking water quality since completing his PhD in Cryptosporidium in 2000, Rob leads a team of scientists, engineers and town planners. Rob is also studying toward a law degree from Monash University. robert.considine@ melbournewater.com.au KNOWLEDGE: Christobel Ferguson is the Research and Development Director and Practice Leader Water Sector for Ecowise Environmental. Her research includes modelling pathogen loads from drinking water catchments, and the application of new methods to quantify and prioritise pathogen risks to drinking water quality. She is also Co-Convenor of the Catchment Management Specialist Network of the Australian Water Association. cferguson@ecowise. com.au. David Sheehan is the Manager, Drinking Water Regu lation Department of Health, Victoria. David has been in his current role at the Department of Health for five years. Prior to that, he had involvement in the water industries of New South Wales and Queensland. He has spent most of his working life as a water microbiologist, but is now involved in policy development and the administration of Victoria's Safe Drinking Water Act. David. Sheehan@dhs.vic.gov.au TOOLS: Pat Feehan has 35 years experience in catchment, natural resources and water quality management and manages his own consulting business in Shepparton, Victoria (email pfeehan@ mcmedia.com.au). Anthony Brinkley is a Senior Associate with Sinclair Knight Merz and has over

20 years ecperience in hydrogeology and water resources management (email abrinkley@skm.com.au). STRATEGIC PLANNING: Bob Ford is the Former Manager of Catchment Policy for Central Highlands Water (retired). Email: bob.ford@ncable.net.au. Nicole Lewis is a Catchment Management Officer at SA Water. She has a strong interest in legislation and policy and is involved in integrated natural resource management and development planning. Nicole is also working towards her Masters in Water Resources management. Nicole.Lewis@sawater.com.au DEVELOPMENT CONTROLS: Dr Anna Hurlimann is a Senior Lecturer in Urban Planning at the Faculty of Architecture Building and Planning at the University of Melbourne Australia. Ph: +61 3 8344 6976; Email: anna.hurlimann@ unimelb.edu.au. Bob Ford is the Former Manager of Catchment Policy for Central Highlands Water (retired). Email: bob.ford@ncable.net.au PATHOGENS: Dr David Cunliffe is Principal Water Quality Adviser, Public Health, Department of Health, South Australia. David.Cunliffe@health.sa.gov.au FIRE: Tommie Conway qualified as a civil engineer from University College, Galway, Ireland in 1995 and this year completed a Masters in Water Resources Management at University of Melbourne. He is currently working with Melbourne Water as an engineer in the water supply asset planning team. Katherine Miller, a civil engineer, with additional degrees in both environmental science and business, is a Key Customer Manager with South East Water. FLOOD: Kevin Hellier is the Manager of Tech nical Support within Melbourne Water's Operations and Maintenance Group. He has developed Melbourne Water's drinking water quality management systems since the late 1990s. Melita Steven, a microbiologist, is the Research Programs Manager withi n Melbourne Water's Strategic Planning Group.

water FEBRUARY 2010 129


water source protection feature

RISK MANAGEMENT OF CATCHMENTS FOR DRINKING WATER R Considine, R Ford Introduction Failure to provide safe drinking water can have catastroph ic impacts on a community or city. The entry of a hazard into the water supply of a comm unity can impact large numbers of people in a short period overwhelmi ng the ability of governments and municipalities to respond. Because of t he large number of people at risk of serious illness or death if pathogen contaminat ion were to occur, The Australian Drinking Water Guidelines emphasise t hat: ... the greatest risks to consumers of drinking water are pathogenic microorganisms. Protection of water sources and treatment are of paramount importance and must never be compromised. Even if no illness is detected t he percept ion that t he water supply system is not safe can destroy a commun ity's trust in its wat er supplier. This can take years to restore. The economic costs to the comm unity and to the utility (in both financial terms and use of internal resources that could have been better utilised elsewhere) will be very large.

Assessment of Risk Managing a water supply system involves the establishment and continual su rveillance of multiple barriers to contami nation. Protection of source water is the first of these barriers. Hrudey and Hrudey (1) in their book Safe Drinking Water point out t hat: Once human development occurs in a catchment the range and magnitude of water quality problems grow substantially along with the difficulty of successfully managing them . Development once allowed cannot be easily reversed .... Society needs to assure that competing water use demands are satisfied in a manner that will not allow other valid water users to externalise their true costs by polluting water needed for critical use such as drinking water supplies. There is such a large number of water borne hazards that routine testing for

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their presence is impossible. Testing for indicators has been a useful common practice for many years but this assumes that the indicators behave in a similar manner t o al l hazardous agents they are assumed to represent. This is clearly not the case. For example, some pathogens can survive long periods of dry conditions, many have different reactions to t he common disinfectants used in water treatment, Viruses are able to be transported more rapidly t hrough soil than indicator bacteria. As well as pathogens algal blooms can release potent neurotoxins that are extremely difficult to detect. There are many taste and odour causing agents attributable to algal blooms and t hese often result in more common and over t he long term, more expensive, impacts on t he operat ions of the utilities. There are over 50,000 industrial chemicals in use in Australia, the majority of which have poor toxicological data, in addition, with an increasingly competitive horticultural sector there are ever increasing numbers of "new age" pesticides and herbicides in use. While water treat ment, disinfection and testing are extremely important aspects of water quality management a risk management plan is not complete unless it contains source protection. To minimise risk, sou rce water should be protected as far as possible from pollution. In any com mercial environment, as in a utility, it is critical to understand the costs of managing risks at source and balance t hese with the costs of t reatment. In general, the financial and social cost of fai ling to protect both the quantity and quality of water supply sources will far outweigh t he cost of additional treatment, especially when the multiple benefits (i.e. environmental and social amenity, biodiversity, agricultural productivity, etc) are taken into account in economic measures. In any assessment of public health risk t he ability to draw on a secure high quality source will result in a lower overall risk than accepting a polluted source and providing a high level of treatment together with the high level monitoring

and management systems needed t o assure safe water at all times.

Risk Assessment and Identification Because of the heavy responsibility to ensure safe and acceptable drinking wat er, risk management is a critical aspect of managing any water supply system supplying drinking water. Risk management involves two key steps which are well known within t he ind ustry 1. Identification and Assessment of r isks, followed by 2. Eliminat ion of the risk or Implementing controls that manage the identified r isks. (where the risk cannot be eliminat ed). The identification and assessment of risk will be very specific to each source (whether it be a catchment, grou ndwater aquifer, marine environment or recyc led wat er source). While there are a num ber of generic f rameworks t hat can be applied a substantial effort involving t hose who are thoroughly knowledgeable with t he catchment will be necessary. Equally important is the involvement of experts in pat hogens, organfc chemicals, algal blooms and customer values. Useful sources of informat ion can also be found in t he lit erature (2,3). The assessment wi ll be catchment specific but need to identify and consider, among other things, the following: 1. Current land use practices and activit ies 2. Local "hot spot s" 3. Pot ential changes in land use and likely threat s from t hese (involving the local counci l's strategic planners is critical) 4. Adequacy of exist ing planning controls that apply to new development (works and subdivision) or change of use 5. Effectiveness of existing controls (i.e. there may be appropriate regulations and conditions controlling many activities but are they being enforced and are they effect ive?)

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water source protection feature 6. Willingness of other agencies t o be involved and the alignment of thei r priorities with the water authority's need for catchment protection . 7. The political climate (what can be achieved?) 8. State and local policies and how supportive they are, and how effective they are in practice? 9. Likelihood of overseas visitors staying in the region, who may introduce exotic pathogens into the catchment. 10. Risk of contami nation by agricultural chemicals 11. Accessibi lity of the waterways to stock and the general public. 12. Sources of pollution such as failing domestic treatment systems or overflowing sewers and the level of maintenance and performance of these systems 13. Length of waterways with adequate buffer strips 14. Level of community awareness

supplied drin king water. Therefore, it is vital that treatment and catchment managers participate in the "source t o tap" risk assessment process, and agree on a balance between multiple barriers in the source water and downstream barriers, based on effectiveness and cost. Because of the extreme public health implications the adopt ed control measures must be understood and accepted by all employees involved in the catchment. In many cases the Catchment Risk Management System can become a subsection of a larger Water Quality Risk Management document written by an external party residing in head office. Clearly if it is to have any effect and credibility operational staff should understand the high level of responsibility their authority, and they, have to the commun ity. If it is to be implemented effectively, operational staff must be intimately involved in its development and have ownership of the control measures and be provided with ti mely feed back from the monitoring system to help them identify and manage the ever changing risks.

15. Frequency or opportunity for illegal dumping and unhygienic activities

The joint AW/VAWWA publication Watershed Management for Drinking Water Protection provides a number of useful case studies for catchment managers.

16. Likelihood of spills from agricultural activities and along transport routes (especially near waterway crossi ngs)

References

17. Effect of storm events on water quality, especially following a long dry period

2

18. Effectiveness of downstream treatment and a balanced approach between source protection and treatment.

3

For each identified event or situation an assessment of the likelihood and consequences will be required generally using the approach set out in AS/NZS 4360:2004 Risk Management.

4

Hrudey S. E. and Hrudey E.J. (2004) Safe Drinking Water- Lessons from Recent Outbreaks in Affluent Nations, IWA Publishing. Roser and Ashbolt (2007). Research Report No 29. Source Water Quality Assessment and the Management of Pathogens in Surface Catchments and Aquifers, CRC for Water Quality and Treatment. Miller, Guice and Deere (2009). Research Report No 78. Risk Assessment for Drinking Water Sources. CRC for Water Quality and Treatment. Western Water v Rozen & Anor [2008] VSC 382 (29 September 2008).

Risk assessment can be uncertain especially where there is limited knowledge or understanding of the processes involved. However where public health is involved a precautionary approach is essential. In a recent legal challenge by a Victorian water utility to a civi l administrative tribunal decision to permit a subdivision in a catchment, the Victorian Supreme Court held that the water utilities were entitled to use The Precautionary Principle in their decision making with respect to catchment management (4). In a large cat chment with a large number of hazards the risk assessment process provides a way of prioritising management action so that the highest risks are dealt with first.

Identifying and Implementing Controls The usual steps involved in identifying and implementing controls are: 1. Evaluation of preventative measures to eliminate an existing or prevent an anticipated risk 2. Evaluation of control measures to manage the risk (balance the costs/ benefits of source protection with ongoing treatment) 3. Design of a management system to monitor the risk creating activities, provide early warning of breakdown in the control measures and initiate a rapid restoration of the control 4. Implementation and monitoring of the system 5. Management of incidents and emergencies. It can be said that the multiple barrier concept advocated by the Australian Drinking Water Guidelines implies the need for endless source protection and treatment, this is the wrong interpretation. The multiple barrier concept advocates that the failure of a single barrier should not compromise the quality of

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water source protection feature

CATCHMENT KNOWLEDGE THE UNDERRATED BARRIER TO WATERBORNE DISEASE C Ferguson, D Sheehan Introduction The Australian Drinking Water Guidelines (ADWG) emphasise a proactive approach to the management of drinking water supplies through the development and implementation of risk management plans. The application of risk management principles requires a detailed description knowledge, and understanding of the water supply system, wh ich stretches from the catchment area, where raw water is collected, to the point where treated water is supplied to the customer. Risk management under ADWG is based on the application of multiple barriers to contamination. Catchment areas are often described as the first barrier in this multi -barrier approach to the protection of drinking water quality. Well maintained catchment areas improve the quality of source waters. Catchment areas are often very large. They can include sub-surface, as well as surface areas, and frequently contain a large variety of land uses, ranging from undisturbed forest, to improved pasture for agriculture to areas of urban development. Therefore, knowledge of the catchment, and its impact on water quality, is essential to determining the hazards that need to be managed and the implementation of the relevant control points. This knowledge can be gained through survei llance and monitoring programs.

Surveillance To understand the catchment area, visual inspections, otherwise known as surveillance, of the catchment should be undertaken.

• Environmental stewardship undertaken by landholders related to duty of care obligations

be used t o map various landuses, identify areas of high risk or track changes over time.

• Regulatory observations for com pliance with relevant land and waterway management legislation

Sanitary surveys are also a useful supplement to routine survei llance and can be used to investigate potential high risk activities or unusual results detected by water quality monitoring programs.

• Validation and verification of hazards and risks • Checking for unusual, unapproved or unlawful activities • Inspections following incidents e.g . wildfire, heavy rainfall, spills or unauthorised discharges • Proactive management of catchments to predict risk events/activities. Surveillance activities are often separated into pro-active and reactive activities. The frequency of surveillance is often related to the level of risk identified in the catchment. Catchment areas wh ich are closed to access typically require less survei llance activity than open, multi-use catchments.

Surveillance activities have multiple benefits with regard to risk and vu lnerability assessments of water supply systems and are the key activity that wi ll increase a utility's knowledge and understanding of its catchment area. The objectives of survei llance include:

Surveillance techniques range in sophistication from the traditional visual on-site inspections, t o aerial photography, remote sensing and satellite imagery.

• Observation of general landuse activities and landuse changes

GIS is increasingly been used a surveillance management tool, as is can

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One final advantage of surveillance is that the very action of being seen proactively patrolling the catchment can send a positive signal to landowners that the utility does care about land management issues and is interested in their activities.

Monitoring The primary objective of monitoring is the detection of changes in raw water quality. However, withi n a risk managementbased framework, and particularly a framework based on HACCP (Hazard Analysis Critical Control Point) principles, monitoring is primarily used to validate and/or verify of the effectiveness of identified critical control points. Monitoring is also used to measure the dynamic range of variations in raw water quality from the catchment. Baseline data collected in dry weather will adequately reflect the risk to water quality most of the time, but it will not be adequate to predict the increased risk that typically

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water source protection feature occurs during wet weather events and following incidents. Other factors that need to be evaluated to adequately describe the hazards within the catchment and the subsequent likely level of risk include: • Seasonal effects • Rainfal l and runoff • The influence of landuse changes on water quality • The influence of farm management practices on water quality • The impact of the implementation of best management practices. These factors can be estimated via monitoring and sometimes modelling. What water quality parameters are included in the monitoring program , where they are monitored and the frequency at which the monitoring occurs should be determined by the risk assessment. Monitoring programs tend to be expensive, so monitoring programs should be tailored to reflect the issues identified in the risk assessment. Monitoring can be undertaken in the field, using portable measuring instruments, or by the collection of samples, which are then submitted to a laboratory for analysis. Preferably, the laboratory will be NATA accredited.

meaningless. Laboratories can provide advice on correct sample collection and transportation.

reafforestation) and changes in stream management (fencing off and vegetation of stream banks)

The use of pro-active monitoring for the detection of specific sources of contamination within the catchment can be used t o identify and prioritise problems. Microbial Source Tracking (MSD uses microbial markers that are specific to particular hosts to identify sources of contamination. The aim of these techn iques is frequently to discriminate between human and animal sources of faecal contamination. Th is type of monitoring can be partic ularly effective when combined with sanitary surveys and surveillance.

Conclusions

Finally, monitoring can also include the recording of changes within the catchment, and monitoring the policies and practices of other agencies, wh ich can provide an early warning of developments or activities that may impact on water quality. Monitoring catchment changes should include creati ng a record of physical changes. This could include changes in land use, (such as number of new dwellings and their location), changes in vegetation (such as clearing of timber or

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If field-based measurement is being undertaken, care needs to be taken in selecting an instrument which accurately measures the parameter of interest. Additionally, instruments should be regularly calibrated and maintained, as the manufacturer's specifications, to ensure that they are recording meaningful data.

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In situ data loggers, which can remotely collect and transmit water quality data, can also be utilised, but as with any field-based measurements, reg ular calibration and maintenance of the instruments is required to ensure that the water quality data which is being collected is meaningful. If samples are being collected for submission to a laboratory care should be taken to ensure that the correct type of sampling container is used to collect the sample, that the appropriate preservation technique is used to transport the sample to the laboratory, and that the sample is submitted to the laboratory within the recommended holding time. The results of poorly collected or poorly preserved samples undermine the potential benefits of monitoring, as the results may be

Collection of Catchment Know ledge is an important on-going activity for many water utilities, Natural Resource Management and Catchment Management Authorities. The v alue of this collected knowledge and information is often under-rated, probably because it is not easily quantified in dollar terms. However, this information informs risk management plans for the essential first step in any water supply which is the collection of the raw source water. The knowledge of how to manage this raw water and to protect it from contamination is vital to reduce the need for downstream treatment and control measures. Although sophisticated treatment processes are widely available these are not infallible. There are also many supplies that still rely on the provision of raw, unfiltered and sometimes un-disinfected water and it is in these situations that catchment knowledge contributes significantly to the prevention of waterborne d isease outbreaks.

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water source protection feature

TOOLS AND RESOURCES FOR CATCHMENT AND GROUNDWATER MANAGEMENT P Feehan, A Brinkley Context The aim of this article is to provide a quick overview of some of the classes and types of tools available to catchment and groundwater managers along with some examples of useful tools. Catchment managers need a variety of tools to assist management. Tools are required for each step of the management cycle which includes assessment, planning , implementation, monitoring and evaluation. Modern organisations are called upon to be smart, fast, agile and responsive and this is impossible without using good tools. When practitioners think of tools they perhaps automatically think of computer based tools such as models, GIS, visualisation tools, remotely sensed imagery and electronic databases. However tools for catchment and groundwater management can include things such as management systems and frameworks (e.g. the Australian Drinking Water Guidelines), best management practices, communication tools (such as conceptual models) as well as tools for managing the social and economic aspects of catchment management and systems or methods of turning data into information and knowledge.

Tools for Catchment Management Here are some examples of catchment tools that the authors have found useful over the years.

Catchment Hydrology (CRCCH undateda; CRCCH undated-b). They discuss the major considerations in selecting an appropriate model for a particular application. They are available from the eWater CRC toolkit webpage: http://www. toolkit. net. au/modelchoice/ Catchment Modelling Toolkit

The Catchment Modelling Toolkit (http://www.toolkit.net.au/) is a source of software tools and information relat ed to the modelling and management of water resources. The cat chment modelling toolkit is populated with a number of models and tools arranged around the themes of:

Storage and aquatic ecosystem models

Water informa tion

The University of Western Australia's Centre for Water Research (http://www.cwr.uwa.edu.au/) has developed a series of models capable of describing the interaction between individual transport and mixing processes in stratified lakes, estuaries and coastal seas. These fluid dynamic models can be coupled with Aquatic Ecosystem Dynamics models to allow for investigations into nutrient and metal cycling over a range of spatial and temporal scales across and within ecosystems.

In Victoria, the Water Resources Data Warehouse http://www.vicwaterdata. net/vicwaterdata/ disseminates up-todate information on Victoria's surface water and groundwater resources through the World Wide Web. The site gives access to both raw and summary data on both water quality and quantity throughout Victoria, and is a central repository for published documents produced from this data. Water information (quality and quantity) can be accessed. There is a lag between data collection and its availability in the warehouse.

• Ecology and restoration • Catchment modelling

Conceptual diagrams

Papers to assist better understand catchment modelling and model selection were produced by the CRC for

The Catchment Toolkit also includes a tool for creating dynamic conceptual diagrams called Concept. It is a drawing

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The Victorian Department of Sustainability and Environment (www.dse.vic.gov.au) maintai ns the Catchment Information Mapper which allows display and query of land and cat chment themed spatial information along with administrative boundaries and contextual information. A range of other spatial information relevant to catchment management is also available.

• Monitoring and assessment.

• River management

Selecting models

Models help codify knowledge and they can help managers determine the effect of particular management interventions and demonstrate to land managers where action will have greatest effect.

Catchment information

Victoria's Resources On line (http://new.dpi.vic.gov.au/vro) (VRO) is a gateway to a wide range of natural resources information and associat ed maps at both statewide and regional levels across Victoria. Other states offer may offer similar information.

• Urban water

Conceptual diagrams are an effective tool to communicate complex messages in a simple and informative manner. In most cases they can be thought of as 'Thought (or Mind) Drawings' or "mind models". More information and resources can be found at http://ian.umces.edu/

Models

package that allows the user to display the important elements of a scenario in a visually appealing way and to show the links between these elements.

Knowledge bases

A knowledge base is a special ki nd of database for knowledge management, providing the means for the computerised collection, organisation, and retrieval of knowledge. An example is the Corangamite CMA Knowledge Base. (http://www.ccma.vic.gov.au/) which is an extensive collection of publications and tech nical reports on all aspects of the catchment.

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water source protection feature prot ect groundwater resources from overdevelopment and contami nation . Groundwater source protection and the development of source protection plans is desig ned to safeguard groundwat er supplies. It is a preventive measure aimed to protect existing and potential g roundwater su pply a reas from contami nation. Once a grou ndwater supply is contaminated, a landholder or a community is faced w ith the difficult and costly task of installing t reatment facil ities or locati ng an alternative water supply. Groundwater source protection involves the management of land around a groundwater bore to prevent this situation arising, or minimising additional impacts if the contamination is already occurring . A Groundwater Source Prot ection Plan combines hydrogeological, land use, water supply and p lanning information to provide a means of protecting a groundwater supply.

Groundwater source protection goa ls

Figure 1. Water Protection Area Signage used in Germany and the USA.

Other useful tools Water Quality Online (http://www.wqonline.info/) is the home of the National Action Plan for Salinity and Water Quality's Queensland Water Quality program. The Water Quality program has prod uced a variety of tools and software to provide guidance to Regional Bodies and other stakeholders. These tools are designed to assist in target- setting, planning, interpretation and st at istical analysis.

Tools for Groundwater Source Protection Context Groundwat er plays an important role as a resource used for human consumption, agricu lture, industry and for environ mental sustai nability. Increasingly, groundwater is used in many towns and urban centres as a potable water supply. Resource managers are cal led upon to

Principles of groundwater source protection (USEPA, 1991 ) include: 1. Providing time to react to inc idents of unexpected contam ination

2. Lowering concentrations of a contaminant to target levels before contaminants reach a bore 3. Protecting all or part of t he Zone of Contribution from contamination Groundwater source protection tools A variety of tools are available to aid in developing source water assessments.

NIWA Freshwater Tools (http ://www.niwa.co.nz/our-science/ freshwater/tools) showcases some of the useful methodo logies and software developed by New Zealand's National Instit ute of Water and Atmospheric Research. Two useful tools include Time Trends and Knowledge o n Attenuation. Current recommended practices (CRPs) Documentation of CRPs (or best management practices) is an important way of highlighting or demonstrating com munity expectations of land and water managers. There are numerous compilations of CRP or BMPs - a Google search w ill soon find examples. Many CRP documents or compilations simply describe the practice but t few actually document how efficient the practice is at achieving desired outcomes.

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water source protection feature The tools include general information on water quality and surface and ground water hydrology, as well as specific information on watersheds, aquifers and public water supplies. Protection tools - information resources or programs that may be of use when implementing protection measures for drinking water sources. Susceptibility determination tools tools and databases that might be of use in determining the susceptibility of a source of drinking water to contamination, including risk assessment and health effects information. Delineation tools - tools and databases that might help in mapping areas that are the source of a drinking wat er supply. Potential contaminant source inventory tools - tools and databases that might be of use in completing contaminant source inventories.

The Guidelines For Groundwater Protection in Australia (ARMCANZ, 1995) recommends the development of a groundwater source protection plan for all public supply wells , whether they are in shallow unconfined, vulnerable systems; or deep confined aquifers of low vulnerability (ARMCANZ, 1995). ARMCANZ (1995) also promot es the concept of a groundwater source protection plan, which is a system of groundwater protection involving a suite of linked components: Well Integrity Assurance: A set of actions to assure that the well is properly designed and constructed to achieve the protection objectives. Wellhead Protection Zones: The delineation of protection zones around the wellhead aimed at protecting that part of the groundwater flow system which contributes to the discharge of the well. Monitoring System: A system in place to ensure that the water quality in the aquifer and in the pumping well are monitored to protect against contamination. Contamination Sources/Land Use Control: Documentation of the location and nature of existing and past contamination sources needs to be documented and controls placed upon these land uses, or potentially contaminating land uses, within these zones.

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Groundwater Source Protection Techniques There are numerous methods used in the definition of areas for groundwater source protection. In the USA, methods commonly used to define wel lhead protection areas include arbitrary fixed rad ius, calculated fixed radius, simplified variable shapes, analytical modelling, hydrogeological mapping and numerical modelling (Cleary and Cleary, 1991 and USEPA, 1993). It has been observed both overseas and in Australia that the most effective delineation techniques involve those which rely on a technical understanding of the hydrogeological environment, rather than the more primitive manual methods.

Further Information There are many graphical or spatiallybased tools available either commercially or in the public domain to assist in groundwater source protection. These include numerical models, geographic information systems, mapping tools, spreadsheets and guidelines. For further information on available tools and guidelines, please refer to the following websites: Australian Government site containing information on water policy http://www.environment.gov. au/ water/ publications/environmental/groundwater/ index.html Unit ed States Geological Survey - site containing public domain groundwater software - http://water.usgs.gov/ software/lists/groundwater/

United States Envi ronmental Protection Agency - site contain ing information on WHAEM - an analytical element model for groundwat er protection http://www.epa.gov/ceampubl/gwater/ whaem/index.html Canadian guidelines for groundwater protection - http://www.ourwatershed. ca/swp/about.php Irish guidelines and tools for groundwater protection - http://www.gsi.ie/ Prog rammes/Groundwater/Projects/ Groundwater+Protection+Schemes.htm

References ARMCANZ, (1995). Guidelines for Groundwater Protection in Australia. National Water Quality Management Strategy. Agriculture and Resource Management Council of Australia and New Zealand - Australian and New Zealand Environment and Conservation Council, September 1995. AWRC, (1992). Draft guidelines on groundwater protection, National Water Quality Management Strategy, Australia. Brinkley, A. J. (1998). Wellhead Protection Guidelines - A Victorian Perspective. Thesis submitted to the University of Melbourne in partial fulfilment of the requirements for the Degree of Master of Applied Science, June 1998 Cleary, T.C.B.F. and Cleary R.W., (1991). Delineation of wellhead protection areas: Theory and practice. Water Science and Technology. Vol. 24, No. 11, pp. 239-250, 1991 CRCCH (undated-a). Series on model choice - 1 General approaches to modelling and practical issues of model choice, CRC for Catchment Hydrology. CRCCH (undated-b). Series on model choice - 2 Water quality models - sediments and nutrients, CRC for Catchment Hydrology. USEPA, (1993). Guidelines for delineation of wellhead protection areas. Groundwater Protection Division, Office of Ground Water and Drinking Water, U.S. Environmental Protection Agency, Washington, DC.

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STRATEGIC LAND USE PLANNING R Ford, N Lewis Introduction The quality and quantity of water available to any water supply system is dependent upon the activities performed in the catchment (or intake areas in the case of groundwater sources). Land use planning controls that exist in all states of Australia provide a mechanism whereby new or proposed activities on land within a catchment area or aquifer intake area can be managed with a focus on water quality protection. Failure to implement appropriate planning controls can: 1. Increase the health risk t o consumers

2. Increase the cost and complexity of water treatment systems

3. Increase the difficulty of maintaining effective water treatment 4. Increase the risk of pol lutants and pathogens entering the distribution system. Especially following storm event s when the treatment plant is challenged

5. Decrease on the reliability of the water resource. By consumptive use withi n the catchment or altering the hydrologic behaviour of the catchment (i ncreasing runoff and reducing base flows) 6. In extreme cases force abandonment of a catchment as a water source.

Responsibilities of Water Agencies

contaminated water from a surface water supply directly affected by livestock4 â&#x20AC;˘

Water authorities have a statutory and moral obligation to take every precaution to provide safe drinking water. Where the public has been placed at risk from a failu re (or perceived failure) the customers, t he community and politicians are unforgivi ng (creating the "outrage factor"). In Victoria the Safe Drinking Water Act 2003 (SOWA) places a statutory obligat ion on water authorities to identify risks and have a risk management plan in place t hat extends from catchment to tap (this includes bulk suppliers that supply water to retailers for domestic use).

Because of t he risk of treatment system failure The Australian Drinking Water Guidelines 2004 (ADWG) 5 require water authorities to have a multiple barrier approach to the protection of water quality and have a program in place to monitor the performance of each barrier. The guidelines stress t hat t he first barrier is source water protection. Health Authorities advise that the greatest threat to public health is from pathogens. The ADWG states, as a basic guiding principal, "The greatest risks to consumers of drinking water are pathogenic microorganisms. Protection of water sources and treatment are of paramount importance and must never be compromised. "6 Routine water test ing is an important means of identifying trends that may provide an early warning and for reporting performance but is not an acceptable method of ensuring safe drinking water as it is virtually impossible to recall any water found to be contaminated.

Water treatment plants alone are not considered to be sufficient to ensure absolute protection. Treatment systems fail for many reasons. Recent examples include a fluoride overdose due to combination of plant failure and human errors in Brisbane 1 , the death of seven persons at Walkerton, Canada due to contami nation of the water supply from animal manure combined with plant failure and human error2 and t he 1998 Sydney incident where a boil water notice was issued on t hree occasions for the whole city resulting in estimated direct cost to the water corporation of $30M3 . In Victoria in 1987 approximately 6,000 persons in Sunbury were affected by an outbreak of gastroenteritis due to

Catchment Policies Planning controls are driven by policy considerations and strategic land use objectives. Water authorities should have a clear long term vision of how t hey want their catchments to look into the future. The absence of such a vision leaves the

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water source protection feature management and development of the catchment totally in the hands of others who usually have a different long term strategic objective to the water authority. A well thought out policy provides a document that can be used to guide and influence the activities and decisions of other agencies such as planning authorities, catchment management authorities and governments. In Victoria Section 60 (1 A) of the Planning and Environment Act provides statutory support for any policy of a statutory authority. It requires that the planning authority may, where circumstances appear to so require, consider any adopted policy of a public authority. Legal opinion indicates that this obliges the planning authority to consider the policy where it is plainly relevant to the subject matter of the application. 7 A catchment policy is also essential to guide staff when assessing development applications and provides a public document that clearly indicates to the community the criteria against wh ich their development applications will be assessed. The development and implementation of a policy provides the senior levels of management and directors of a water authority reassurance that they are complyi ng with their obligations to provide safe drinking water. (Following the Sydney incident, Sydney Water lost the trust of its community, was subject to criticism by the Royal Commission established to investigate the incident and both the Chairman and General Manager resigned.) The existence and implementation of a policy demonstrat es to the community and customers that the water authority takes its responsibilities for providing safe drinking water seriously.

Planning Controls

be protected for their water quality improvement potential, areas of highly erodible soils where development should be limited, steeply sloping land and areas close to waterways where rapid runoff would cause immediate pollution with limited or no opportunity for mitigation.

3. Set tight boundaries for urban areas to limit development to clearly defined areas in a sub-catchment where stormwater and wastewater can be collected and treated.

4. Set a development limit to prevent ongoing incremental development gradually overtaking the catchment.

At a local level planning controls should: 1. Require collection and treatment of surface run off from developments as wel l as providing a clear obligation for any development application to demonstrate how it will enhance the quality of water and how wastewat er wi ll be managed to the satisfaction of the water authority.

2. Require liaison with the water authority for development applications in high risk areas, or where the development limit is likely to be approached or exceeded.

3. Be compatible with the long term strategic objectives of the water authority 4. Prohibit inappropriate development in the catchment (such as large intensive animal husbandry, and high risk industries) 5. Require new development to be set back from water courses to provide buffers and require these to be vegetated. 6. Control the density of development in the catchment. Best Practice management suggests that planning controls should

Planning controls should consider both the strategic and local aspects of catchment management.

1. Zone the bulk of the catchment for an activity that results in minimum impact consistent with local conditions. This is usually broad acre agricultural or forestry.

At a strategic level the controls should identify risk, especially risk from incremental development, and enable planning agencies to:

2. Only permit additional dwellings should where absolutely necessary for broad acre land use.

1. Clearly identify the catchment boundaries and have them recorded on the planning maps. This provides a mechanism that brings the existence of the catchment readily to the attention of the public, potential developers and planners. 2. Identify high risk areas and areas of importance such as wetlands that should

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6. Prohibit development on inappropriate soils, wetlands and floodprone areas 7. Require applications in high risk areas

to be referred to the water authority

8. Control the number and size of farm dams 9. Prohibit high risk activities

10. Identify the catchment on planning maps to alert planning officers and applicants to the existence of the catchment. 11. Require on site wast ewater treatment systems to be maintained and audited regularly for compl iance with manufacturer's specification. 12. Identify extremely high risk areas such as land in close proximity to a reservoir to be reserved for ultimate acquisition by the water authority. To ensure compliance with the planning controls education and actively patrolling the catchment to encourage landowners to have regards to water quality and detect inappropriate development early is essential. Where landowners perceive that no interest is being taken in their activities it is unreasonable to expect them to comply with activities designed to protect the water quality and quantity of local streams.

Conclusion Land use planning is an important com ponent in protecting public health and cost of treatment. Water authorities should be proactively involved in influencing the development and implementation of planning policies aimed at protecting water supply catchments. They should also seek to have development applications referred to them and be active in assessing planning applications against published policies.

References

2

3. Require collection and treatment of stormwater and wastewater

4. Specify setbacks from watercourses and require vegetation of buffer strips 5. Requ ire applicants for development approval to demonstrate to the satisfaction of the water authority that wastewater and stormwat er wi ll be appropriately managed

Queensland Health (June 2009). Investigators Report: Water Fluoridation Incident, North Pine Water Treat ment Plant. Queensland Government, Brisbane Hrudey Sand Hrudey, E (2004). Safe Drinking Water Lessons from Recent Outbreaks in Affluent Nations, IWA Publishing, London p95-122

3

Ibid p351-352

4

Ibid p 186-187

5

Nation Health and Medical Research Council, Australian Drinking Water Guidelines (2004), Australian Government. p1 .2

6

Ibid p1 .1

7

McDonald v Moorabool SC [2005] VCAT 1764 (1 2 August 2005)

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water source protection feature

DEVELOPMENT CONTROL WITHIN CATCHMENTS A Hurlimann, R Ford Abstract

,.------- - - - -

Effective urban planning policy and decision guidelines are requi red to ensure the protection of water quality, and to guide local planning decisions where a conflict of interest may exist. This paper analyses some landmark cases where the Water Authority had to fi ght to exercise its right to protect its source of supply.

Introduction The potential to address protection of water quality through effective urban planning policy is currently unrealised. Int ernationally, there have been calls for a catchment-based approach to integrating water, land use and ecosystems in order to achieve ecological sust ainability (Falkenmark 2003). However this has not been fu lly translated into urban and regional planning policy in Australia. The possibility of the contamination of water supplies in affluent nations and the devastating impact this can have on populations is demonstrated by Hrudey and Hrudey (2006) through seventy case studies. Many of the cases described have involved serious illness or death in populations who have had t he misfortune of drinking from a contaminated water supply. One of their key messages is the importance of protecti ng potable water catchments from inappropriate development. The authors acknowledge that once developments occur in a watershed the range and magnitude of wat er quality problems grow subst antially along with the difficulty in managing them successfully.

Urban and Regional Planning Policy and the Protection of Water Quality in Victoria Development control in the state of Victoria is primarily activated at the local level and is contained in each local government area's planning scheme. Zones control land use and development, while overlays control development only.

Some Victorian case studies.

Council overruled the water authority's objection that this site was subject to local flooding. They eventually had to require the owner to rebuild the wastewater disposal area above ground within the large mound visible at the rear of the house.

Each zone and overlay has specified policy objectives that they are intended to achieve and development applications are assessed against these objectives. An important aspect of development control with regards to catchment management is the role of referrals in t he Planning and Environment Act 1987 (The Act). Water authorities become referral authorit ies under section 55 through Amend ment S9 to planning schemes in 1992. Decisions made by responsible authorities can be reviewed (appealed) by the Vict orian Civi l and Administrative Tri bunal (VCAn. Decisions of the tribunal are binding on all parties to the proceeding appeal and are final, subject only to the rig ht of appeal on a question of law.

Method This research analysed selected VCAT decisions regarding development proposals in potable water catchment areas in the Central Highlands reg ion (formerly managed by the West Moorabool Water Board). A list of VCAT decisions is available backdated to 1995 on line, at the Australian Legal Information Institute http://www.austlii. edu.au/au/cases/vicNCAT/ . Decisions prior to 1995 were obtained from the Victorian Public Record Office.

Development appeal cases prior to water authorities becoming refe rral authorities (pre-1992)) The fi rst two cases relate to ap peals by the water board regarding the Council's decision to grant a permit, as t he proposals were not referred to the water authority. West Mooraboo/ Wa ter Board v Wade and Carey was one of the most significant. The Council decided that the two houses wou ld not be a risk to the water catchment, thus they granted a permit. In Carey's case, the application was received on t he Friday before the scheduled Council meeting. Th e permits were granted on Monday afternoon after the meeting. The water board suspected this was done to prevent them objecting. When the water board found out about the permits (from their reg ular inspection of the register) they applied to have the permits cancelled. Jones' (the VCAT Member) determined that it was outside the expertise of Council to mak e a decision on catchment risk. However, it would not be fair and reasonable to cancel the permits but he added a number of additional conditions (onerous) to the original permits. The houses were never built. Similar cases at VCAT included West Moorabool Water Board v Chelmaness Pty Ltd and others, and Mc Tigue v

water FEBRUARY 2010 139


water source protection feature Chelmaness & Svoboda. These cases demonstrated that Councils' primary interests were not wat er quality protection but to encourage local development, and because of this conflict they were not addressing the interests of the water authority.

Other VCAT appeals (Water Board v McLean, O'Brien, Harden) set precedents for protection of Agricu ltural A Zone in a potable water catchment, and concern about incremental development. Another significant case in this period is that of Rinaldi v West Moorabool Water Board. The application was for a two lot subdivision. The water board argued that the catchment already had over 2500 existing lots and that allowing the application to go ahead was bad planning and would set a bad precedent. The site also had poor soil for effluent disposal. Following this case, the Water Board won the next 17 cases arguing on planning principles and not individual technical issues. Through this case, the Water Board realised it was important to get invo lved in planning schemes and try to i'nfluence the zoning and policy statements. The Board found that once counci ls realised they were serious and wou ld take legal action, the Councils became more responsive to water quality considerations.

Amendment S9: key aspects to the amendment process In October 1992 driven by requests from a number of Water Boards, that not all applications in water catchment areas were being sent to water authorities, a ministerial amendment (S9) to all planning schemes in Victoria was approved This change requiring formally referral of all permit applications concerning land that is within an area proclaimed as a water supply catchment area under the then Soil Conservation and Land Utilisation Act 1958 and which provides water to a domestic water supply, to the relevant water board or water supply authority (Stokans 1992). At a panel hearing established was set up to report on this amendment the water boards submitted that: 1) t he fundamental need was for responsible town planning within a domestic water supply catchment, and 2) the need to protect public health. The Boards also submitted that increasing pressure was being experienced to alter the land use in the catchments, from broad acre farming to small hobby farm type development. The West Moorabool Water Board reported t hat it had lodged thirty four

140 FEBRUARY 2010

water

appeals against a Councils' determination to grant perm its in the last three years, twenty nine of which were successful. As detailed by Stokans, the dominant argument from those in opposition was that a non-elect ed body would effectively usurp planning powers vest ed in local Government. Stokans stated it was clear that inappropriate development within catchment areas has the potential to seriously degrade the wat er quality of the state's resources and controls must be imposed to ensure that this does not occur. The Panel found that the amendment was consistent with other state and regional policies dealing with water supply management. Thus, in 1992 the amendment was approved with minor changes to the definition of the use and development requ iring referral.

Deve lopment appeals since Amendment S9 Since the approval and activation of Amendment S9 there have been a number of appeals at VCAT. In the case of Wethling v Moorabool Shire Council, a permit was allowed by VCAT. In this case a small old house burnt down. The VCAT member determined that had the application been for a new house it would not have been granted but given the exceptional circumstances would let the applicant (son of the original owner) build his new (larger) house. In the case of Mackenzie v Moorabool Shire Council the Council failed to refer the application to the water authority and allowed the construction of a house to proceed . The case resolved around the proximity of the water supply off take and the decision was given that no permit be granted. The water authority then asked for an order requiring the house be removed that was granted. In the case of Central Highlands Water Authority v Ballarat City Council the water authority objected to the application for subdivision and construction of four dwellings (in a Rural Zone) even though the development was just outside their catchment, due to the precedent they thought it wou ld create. VCAT determined that the permit be refused given it did not support the zone objectives and would result in t he fragmentation of high quality agricultural land. The cases of McDonald v Moorabool Shire Council and Wells v Mooraboo/ Shire Council are good cases for demonstrat ing the importance of catchment protection and the protection of agricultural land.

In the majority of cases after 1992, VCAT appeals were lodged by the applicant, appealing the Council's decision to refuse the application (as they were required to do under Section 61 (2) of The Act 1987 because of a Referral Authority's objection). However, since 2007 two permits have been granted by VCAT (Daylesford Design Studio v Hepburn Shire Council and Rozen v Macedon Ranges) despite the fact they did not meet the objectives of the planning scheme and also did not meet the objective of the 'Interim guideline for planning permit applications in open, potable water supply catch ment areas' (Department of Infrastructure 2000). For Daylesford Design Studio v Hepburn Shire Council the VCAT member in making their decision questioned the validity of t he Interim guidelines given that they are still interim yet were published in 2000. The water authority called for a precautionary approach in this case. The Precautionary Principle is embodied in Victorian environmental legislation and recognised as a key aspect of ecologically sustainable development (Young 1999). Academics have called for a precautionary approach to risk assessment for drinking water quality (including McKay and Moeller 2001). However the member in the case of Daylesford Design Studio v Hepburn Shire Council in her decision said: I consider these factors weigh significantly in favour of the proposal when tested with the position put by Central Highlands Water. While I agree with Central Highlands Water that the lack of scientific information could be said to favour a cautionary approach, that must be fairly balanced against the provisions of the Hepburn Planning Scheme that give some expectation that a dwelling on the review site is not unreasonable as part of a recognised settlement. In the case of Rozen v Macedon Ranges the interim guidelines were not questioned, however, the application of the precautionary approach to the case of potable water catchments was denied. In their findings the Members for this hearing said they did not consider that the interim guidelines should be read as limiting dwellings to the 1:40ha density. Rather they see that such a guideline is a flag to ensure that water quality issues are examined more critically when dwelling densities will be more than 1:40ha. Such considerations highlight the discretionary nature of the planning process in Victoria. The water authority

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water source protection feature sought and was granted leave to the Supreme Court where their concerns were upheld and the case referred back to VCAT with specific directions to have a stricter regard the Precautionary Principle.

members have not regarded the contamination of water supplies with enough significance, or acknowledgement of the fu ll extent of the problems which may arise as a result of contamination of supplies.

Conclusion

These cases demonstrate the need to continually revisit the importance of catchment protection as demonstrated by Hrudey and Hrudey (2006) of which a number of the cases of contamination described occur in Australian, and Victoria. Higher regard should be given to the impact of incremental change of land use in potable water catchments.

The case of Daylesford Design Studio v Hepburn Shire Council demonstrates the interplay between the hierarchy of importance between the zone and the overlay. The case also demonstrates the common urban planning tension between the rights of the individual property owner versus the benefit of the community (as consumers of water). This decision and others like it, demonstrate the need for the interim guideline to be made permanent (which has since happened, Department of Planning and Community Development, 2009). It also demonstrates the need for the precautionary approach to be applied in development proposals and appeals in potable water catchments and for clearer definition of, and guidance regarding the precautionary principal in order to improve consistency in its application. These cases indicate that the VCAT

Acknowledgments For a full copy of the original paper see Hurlimann and Ford (2008). This research was funded through a University of Melbourne, Faculty of Architecture Building and Planning Early Career Researcher Grant. Thanks to research assistance provided by Julie Hayes.

References Department of Infrastructure. (2000). Interim guideline for planning permit applications in open, potable water supply catchment areas. Victorian Government, Melbourne.

Department of Planning and Community Development (2009). Planning permit applications in open, potable water supply catchment areas, guidelines. Falkenmark, M. (2003). "Freshwater as shared between society and ecosystems: from divided approaches to integrated challenges." Philosophical Transactions: Biological Sciences, 358(1440). Hrudey, S. E. , and Hrudey, E. J . (2006). Safe Drinking Water: Lessons from Recent Outbreaks in Affluent Nations, London: IWA Publishing. Hurlimann, A. , and Ford, R. (2008). "Development Appeals in Victoria's Potable Water Catchments" Proceedings from the Onsite and Decentralised Sewage and Recycling Conference, Coming Clean: Sustainable Backyards & Beyond!: Australian Water Association: 12-1 5 October, Benalla, pp. 388400. McKay, J., and Moeller, A. (2001). "The Status of Drinking Water Quality Reporting, the Precautionary Principle and Public Health in Australia." Ethics and Justice, 3(2), 11-21. Stokans, E. (1992). Amendment S9 to all Planning Schemes. Department of Planning and Housing, Melbourne. Victorian Government Gazette. (1992). "Notice of Approval of Amendment, Amendment S9", No. G39, Wednesday 7th October. Melbourne: Government Printer Melbourne. Young, M. D. (1999). "The precautionary principle as a key element of ecologically sustainable development", in R. Harding and E. Fisher, (eds.), Perspectives on the Precautionary Principle. Sydney: The Federation Press.

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water source protection feature

POSSIBLE CHANGES TO THE ADWG: QUANTIFYING THE RISKS R Ford, D Cunliffe Introduction The National Health and Medical Research Council recently issued a discussion paper on health based targets for microbial safety of drinking water supplies. The proposal would introduce quantifiable targets that provide measurable benchmarks for risk management systems. If adopted, the proposed changes would bring the Australian Drinking Water Guidelines (ADWG) into line with the latest edition of the World Health Guidelines for drinking water as well as current US, NZ and Canadian practice. Australia already has adopted the WHO method for quantifying microbial safety of recycled water.

Definition of Safe Water The greatest risk to consumers of drinking water arises from pathogenic organisms, but microbial safety is currently poorly defined by the ADWG. While ADWG advocates risk management based on assessing risks and reducing them to acceptable levels to assure safety the they fail to quantify what is meant by microbiologically safe water. In other words it fails to identify what benchmarks need to be met by an effective risk management system. Microbial targets described in the cu rrent ADWG are imprecise and based on a premise of seeking "to ensure that drinking wat er is free of microorganisms that can cause disease". The only microbial guideline provided is E. coli. E. coli has been used as the standard indicator of faecal pollution of water for many years and has served the industry very well in that capacity. However it is known that protozoan, viral and other bact erial pathogens behave differently to E. coli in the environment and through treatment systems. Consequently it is not a particularly good indicator of the microbial safety of a water supply.

This will impact on both catchment management and treatment. 142 FEBRUARY 2010 water

... the discussion paper demonstrates the impracticality of direct pathogen monitoring of drinking water as a safe guideline. The Australian Guidelines for Water Recycling (AGWR) discuss in some detail various reference organisms and recommend that Cryptosporidium parvum be used as the reference pathogen for protozoan hazards, Campylobacter be used as the reference pathogen for bacterial hazards, and a combi nation of the dose-response data for Rotavirus and the occurrence data for Adenovirus as the reference for viral hazards. The AGWR adopted the WHO guideline definition for safe water as 1o-6 Disability Adjusted Life Years (DALYs) for each of the reference pathogens (this is a probability measure combining the severity of an illness, the probable period a person is effected plus a probability measure of the length of life lost following any deaths due to the illness, for a given population). The discussion paper considers a number of options currently used in different countries however if a change is eventually made to move to a quantified target the impact will be substantial for water authorities and should provide a better management structure and safer water supply. An important fact to note is that working through the process described in the discussion paper demonstrates the impracticality of direct pathogen monitoring of drinking water as a safe guideline. The concentrations required to achieve the suggested guideline value are so low (less than 1o¡ 5 organisms per litre) that practical direct measurement is currently impossible, and is likely to remain so for the foreseeable future.

Risk Management Approach The approach proposed is to determine the likely concentration of pathogens in the raw water (from measurements or published information) then apply

measured or published data for the reduction/inactivation of each pathogen through each of the collection, storage and treatment processes to determine the likely average concentration in the treated water. This is compared with the guideline value for "safe water" to assess the level of safety and to determine the degree of pathogen reduction required (measured as a log 10 reduction in concentration). A risk based system using this techniq ue is likely to have the following characteristics:

1. A requirement to quantify and monitor the microbial quality of raw water and actively manage catchments to control the level of pathogens entering waterways and aquifers. 2. A requi rement to quantify the impact of the reference pathogens on the local community, and 3. A need to identify and maintain a specific minimal level of removal or inactivation for each barrier or process in the whole catchment, storage, treatment and disinfection train.

Quantifying and Managing the Quality of the Raw Water In 2005 the CRC for Water Quality and Treatment published a report on a study into the occurrence of contaminants in raw water for a number of Australian catchments. The report indicated that:

1. The great est pathogen load occurs during a storm event 2. A number of grab samples during an event will provide reasonable information on water quality at the accuracy required . 3. Increasing runoff appeared not to provide a dilution effect. As a result water authorities should be able to economically determine the order

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water source protection feature of magnitude of the concentration of reference pathogens in their raw water from a reasonable number of event samples. Moreover the process has the added advantage, that by carefully selecting the sampling points to monitored, it enables catchment "hot spots" to be identified and appropriate action to be taken, while at the same time establishing baseline data. Ongoing monitoring will also determine if a gradual reduction in water quality is occurring. The water authority then has quantified information to address the problem with other natural resource management agencies, land use planners and local government. The data provided will also give the water authority information upon which rational decisions whether to spend money on catchment management to reduce the concentrations of pathogens or upgrade the treatment process to increase the level of pathogen removal can be made. Any treatment plant needs to be capable of treating the worst quality raw water it is likely to encounter. However it is likely to be uneconomic to upgrade a plant to meet a 1 in 50 year peak concentration. A more likely option will be that armed with the data provided water authorities become proactive in catchment management. Event sampling provides a process to at least sample when water quality is likely to be at its worst and measures the actual load of pathogens. Ongoing event sampling wi ll be requi red to provide assurance that the raw water quality is not decreasing to an extent that the treatment plant fails to produce "safe water".

processes. The current ADWG calls these "multiple barriers" and advocates that they all be recognised, monitored and maintained. The suggested risk management system will req uire that the degree of removal/inactivation for each of these barriers be quantified (usually measured as Log 10 reductions in concentration). This ideally should be done by physically measuring the reduction in pathogen concentration but published guideline val ues are available for most treatment processes. The chal lenge however will be for water authorities and operators to not only maximise the log reduction through each process but also to monitor each process in their treatment train t o ensure that the quoted design reduction is being maintained at all times. This is a significant change from current practice where usually only t reated water quality, and in some plants filtered water turbidity, is contin uously monitored, w hile the performance of other processes is given a much lower priority. However, a risk-based approach shou ld identify those processes that are most critical in providing safe water. These may be

different for each reference pathogen and will req uire operators to give highest priority t o the more important processes.

Conclusion The NHMRC discussion paper has flagged a change to the way the safety of drinking water can be measured in Australia. The suggestion, if adopted should increase t he level of security and safety for water consumers by providing a quantified risk-based approach. However proactive water authorities and treatment plant operators should begin now to collect base data on their catchments and treatment systems. This would involve grab sampling and analysis of raw wat er from sub catchments during high flow events to build up a picture of the quality of raw water at the most adverse time for t reatment and the identification of hot spots within the catchments. Additionally, investigation into the effectiveness of each process in their treatment train to remove/inactivate the likely reference pathogens should be initiated and processes to accurately monitor the real -time effect iveness of the barriers need to be considered.

Quantifying the Impact of Reference Pathogens on the Local Community This data is available from a number of published sources but the resu lts vary significantly d ue to the volume of water drunk, the level of health care readi ly available and the degree of immunity within a population and different age groups. To support the overall process of incorporating health-based targets into ADWG , Monash University and Water Quality Research Australia (WQRA) have just commenced a project that is looking at the development of Australian-derived DALYs.

Identifying and Maintaining the Specified Level of Removal/Inactivation The process of capturing, storing and treating water involves a number of

water FEBRUARY 2010 143


water source protection: incident management

BLACK SATURDAY IN MELBOURNE'S CATCHMENTS T Conway, K Miller Abstract The 'Black Saturday' fires of the 7th of February 2009 and the continuation of fires over the fol lowing weeks had devastating human, environmental and financial costs for Victoria. Many of Melbourne's water supply catchments and asset s were burnt and t he major harvesting catchments were seriously t hreatened. This paper highlights t he need for owners and managers of catchments, dams and associated infrastructure to better understand and plan for the potential impacts of fire, given its predicted increased likelihood and severity due to climate change.

Introduction On the 7th February 2009 Victoria experienced the most devastating fires in the history of the state. Many of Melbourne's water supply catchments and assets were burnt and the major harvesting catchments were seriously threatened.

Background Melbourne's water supply catchments

responsibil ity for al l aspects of management that impact on the water resource. Melbourne Water has no legislative responsibilities fo r fi re prevention and suppression but it has long maintained an active involvement in fire protection activities.

Melbourne has a total water supply catchment of 156,700 hectares. Of this, 56,300 hectares are State Forest, 90,800 hectares are nat ional park, 7,500 hectares are Melbourne Water owned land and 2,100 hectares are privately owned. Melbourne is one of five major cities in the world where t he water supply is provided from protected catchments. Around 80% of the water delivered to customers originates in protected forested areas which have been closed to the public for over 100 years.

Melbourne Water has three key objectives to protect water quality and yield from the catchments and adjacent areas. These are:

Our fire responsibility

Fire has been identified as Melbourne Water's primary threat to the ability to contin ue to supply potable water to Melbourne. A fire withi n a major harvesting catchment could not only lead to pol lution of the water within the reservoir and damage the supply infrastructure, but it can also reduce catchment runoff volumes in the short, medium and longer terms.

The Department of Sustainability and Env ironment (DSE) is the fire agency for State Forests & National Parks and the Country Fire Authority (CFA) is the fire agency for freehold land. The State Forest and National Park water supply catchments are jointly managed by Melbourne Water, Parks Victoria and DSE. Melbourne Water takes

144 FEBRUARY 2010 wat er

• To minimise the potential for high intensity fires to reduce water quality and yield • To control all fires with m inimal impact on the envi ronment and • To enable and assist recovery after fire.

Fire preparedness

To mitigate the impact of fire in our catch ments Melbourne Wat er has invested heavily in fire preparedness. Agreements are in place including t he Kinglake and Yarra Ranges National Parks, (Catchment Management Agreement, 1995), The Yarra Tributaries Lease Agreement, the Thomson Catchment Agreement and the Fire Protect ion and Suppression Partnership Agreement. These agreements are in place to formalise the interaction between major stakeholders including the CFA & DSE. Melbourne Water's Fire Readiness & Emergency Response and Fire Protection Plans for freehold land govern our internal response to fire. DSE and Melbourne Water are jointly involved in the planni ng and implementation of fuel red uction burning within the catchment areas, most of which Melbourne Water operate as 'closed' catchments. The advantage of closed catchments is that it reduces the risks of ignition due to human activity. The catchments are regularly patrolled by secu rity personnel and operational employees and a comprehensive system of gates, locks, and signage are in place to attempt to control and limit human presence in t he catchments.

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water source protection: incident management The following work programs assist with fire threat response: • Road opening and clearing to established catchment standards and road classifications • Roadside slashing • Catchment road drainage maintenance • Fuel break vegetation maintenance (currently 126 km. Will increase to 500km) • Maint enance of the road network throughout the catchment (1,860 km) for quick access to fires • Water points (including tanks) and water point access maintenance • Helipad vegetation management • Fire detection through 4 Melbourne Water fire t owers are integrated with the DSE and CFA tower network

Figure 1. Melbourne Water's Water Supply Catchments (note hatched area denotes 2006 fires).

• Regular patrols are carried out by Melbourne Water fire-fighters in the catchments and adjacent areas.

• 4 transporters for fi rst attack dozers based at the work centres

• Melbourne Water is also qualified to trai n personnel in fire fighting.

• 4 fu lly enclosed cabin first attack dozers

Fire

Coupled with the work programs throughout the year, Melbourne Water employs summer crews that work with full-time employees and operate as first attack st ri ke teams. These teams live close to the catchments and are required to assemble at staging points at 20 minutes notice. They endeavour to locate a fire and bring it under control before it becomes too large. To assist in this process there are also:

• 1 fully enclosed cabin 06 (large) dozer

Weather in the lead up to the February 2009 bushfires

• 112 trained and accredited fire fighting personnel (i ncludes 52 summer casual project fi re-fig hters). All trained to DSE standards • 25 Slip-on fire fighting units

• 4 Melbourne Water work centres

• A wat er bombing helicopter stationed near our catchments, fu nded by Melbourne Water and managed by the Stat e Aircraft Unit, specifically on standby for catchment protection

• 4 purpose built 3800 litre DSE spec. fire trucks

• There are also predetermined Incident Control Centres for fire incidents that

are located throughout the catchment region .

In the week before the Black Saturday fire, the maximum daily tem perature exceeded 30°C on five days. This was preceded with a very hot spell in January when the maximum recorder daily temperature in Melbourne exceeded 43°C on three consecutive days. The temperature peaked at 46.4°C on the day and winds monitored in Melbourne varied between 40 and 55 km/hr with gusts of up to 80 km/hr.

Event chronology and extent On 7th February 2009, 12 major fires and 1,386 other incidents - including 624 grass or bushfires - occurred across the State (Information from Submissions of the State of Victoria to the Bushfire Royal Commission). Only fi res that affected Melbourne Water assets are addressed in this paper. There were 3 major fires that impacted on our catchments on Saturday the 7th of February. • Around midday the Bunyip Ridge fire that originat ed from a lightning event in the preceding week spotted over control lines and headed towards the township of Warragul before being influenced by the south-west change where it pushed the fire into the Tarago catchments. • At approximately midday the Kilmore East fire started and pushed through the Wallaby Creek and Plenty River

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145


water source protection: incident management catch ments before impacting on local comm unities. • In the early afternoon the Murrindindi Mill fire started and travel led towards Marysville and beyond where it impacted on the O' Shannassy, Armstrong and Upper Yarra catchments. The Maroondah catchment was burnt from a fire generated from lightning originating from the pyro-cumu lous cloud from the Ki lmore east fire and burnt under cool south-westerly conditions over the next week. The Kilmore and Murrindindi fires joined up and were then referred to as the Kinglake comp lex fire. This resulted in a large fire immediately to the north of the eastern suburbs and satellit e towns of Melbourne.

Effects on Melbourne Water's assets The final extent of the burns to the catchments are recorded within Melbourne Water as shown in Table 1. Almost 470 square kilometres of catchment were fire-affected, representing about 30% of Melbourne's wat er supply catchment area.

Table 1. Catchment Percentage Affected. Catchment

Total Area (km2)

Area Burnt

% Burnt

Coranderrk

18.6 25.6 121.2

0.29 25.6 92.4 110.5 59.5 54.5

1.6

Graceburn Maroondah O'Shannassy Tarago Armstrong Wallaby Upper Yarra Bunyip

118.7 112.0 54.5 91.0

plant and equipment were destroyed. The project was delayed for four weeks due to roadblocks and Occupational Healt h and Safety constraints imposed by State authorities and by Melbourne Water.

Operational responses Melbourne Water considers the effects of fire from short-term and a long-term viewpoints. In the short term, water quality is the major concern due to the potential of subsequent rainfall events to wash debris and soil/contaminants into the water supply. The short-t erm recovery works that were undertaken were:

The following major assets were damaged:

• Opening roads and drainage paths

• Approximately 80 km of roads

• Installing sediment traps

• 3 bridges and numerous culverts • Approximately 42 km of fencing

• Rehabilitati ng catchment roads damaged in the fi re fig ht

• Wat er supply infrastructure - Wallaby Weir and Aqueduct

• Increased program for water quality monitoring.

• 2 buildings at Wallaby Creek plus historic Wallaby Lodge

The severely burned catchments were isolated from supply immediately following the fire and were reintrod uced as the threat from material wash decreased. This threat is expected to remain for a number of years and certain reservoirs may again be required to be removed from service as a result of t he February fires if a big rain event occurs in the next couple of years. As an immediate response to the fire, increased volumes of wat er were transferred from the Upper Yarra reservoir, whose catchments were under significant fire threat, to Cardinia reservoir which was considered much safer to secure shortt erm good quality water for the city.

• Many sheds and water monit oring and controlling structures including penstocks, trash screens, flumes gates and signs • 900km of Melbourne Wat ers waterways assets were burned (i .e. the river and stream frontage was burned). Two major water supply augmentation projects were also affected by the fire, the new $100m Tarago treatment plant and the $625m sugarloaf pipeline project. At the Tarago treatment plant construction site the losses were minimal as there were trained personnel at the site at the time. The fi re delayed construction at the site for two to three days; there were minor plant and equipment losses and the newly installed landscaping was also burned. The Sugarloaf pipeline was more severely affected with 28% of the alignment of the pipe burned and nine pieces of heavy

146 FEBRUARY 2010 water

91.0 7.9 27.8

336.7 39.0

• Replacing and clearing culverts

Over the medium term runoff increases are expected. Longer term, water yield reductions can be expected from fireaffected areas due to vegetation regrowth. Melbourne Water has dedicated research areas in the Coranderrk and Maroondah catchments where extensive research on stream flow

100 76.2 93.1 53.1 100 100 2.3 71.3

has continued since the 1950s. The research indicates we may see a 20-30% reduction in stream flow from the affected catchment areas in approximately 30 years time. (Refer to O'Shaughnessy, Langford, Jayasuriya, Howard et al. Publications on the hydrology research from the research catchments are available from Melbourne Water Corporation). The Coranderrk research catchments were not burned in the 2009 fires but the Maroondah research catchments generally were burned wit h some die off of old growth expected. This has provided opportunity to research stream flow after this event and Melbourne Wat er have engaged the University of Melbourne to undertake longer term modelling studies into yield of the fire-affected catchments.

Communication There was significant political and commun ity concern regarding water quality after the fire and an incident management team was set up within Melbourne Water to deal with this. The responsibilities of this team are summarised following: • Externally, - Customer communication - Stakeholder management - Media liaison • Internally, - Provide a daily update - Highlight OH&S issues - Recognise great work - Manage staff well-being. The communication of asset information, detailed mapping of the fire ground and up to dat e fire information are vital in the suppression of the fire and the efforts to mitigate the effects of the fire. Communication before and during the emergency between stakeholders and emergency services is a very important pre-fire consideration as the

technical features


water source protection: incident management implementation of roadblocks by police after fi re events can compromise operators ability t o get to yo ur critical assets.

Table 2. Flood Risk rating as a function of soil burn severity. Post-fire flood risk rating

Soil burn severity criteria (per cent)

US Burned Area Emergency Response {BAER)

High

Intense> 20

What they are

Moderate

The United States, US Burned Area Emergency (BAER) program addresses immediate post-fire emergency situations with the goal of protecting life, property and natural and cultural resources. It was formed following experience in the United States that for some fireevents more lives and property are lost post-fire than during the fire itself, due to landslides and flooding, tree falls and infrastructure failures. BAER Teams are made up of: • Hydrologists • Foresters • Soil scientists • Engineers • Biologists (wi ldlife/aquatic)

Moderate > 80 Moderate < 80 Moderate > 60 Low

Moderate < 60

• Vegetation specialists • Archeologists • Geographic Information Specialists (GIS) They are specially trained professionals who rapidly assess the burned area and prescribe emergency stabilisation treatments. The BAER Assessment usually begins before the fire has been fully contained and must be completed within seven days after containment. Timing is critical , as the prescribed land treatments must be installed before the first damaging storms post fire that threaten the life, property or resource values needing protection.

What they did The American BAER Team was initially int egrated into the Kilmore EastMurrindindi Complex South Fire Incident Control Centre on 9 March prior to containment of the fire . It contained members of the US Forest Service, Bureau of Land Management, and, Bureau of Indian Affairs. The US BAER Team was augmented by many specialists from Department of Sustainability and Environment (DSE), Country Fire Authority (CFA), Parks Victoria and Melbourne Water. The team spent eight days conducting field assessments and c ollaborating with other agencies to identify the priority areas where post-fire conditions pose the greatest risk to life, property or resource values downstream of burned areas. The Ki/more East - Murrundindi South Complex Fire Burned Area Response Report, from which the following sections have been largely sourced, was prepared with primary objectives to: • Recommend post-fire mitigations designed to protect human life, freehold lands, and built assets.

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water source protection: incident management • Recommend post-fire mitigations to st abilise and prevent further degradation to affected catchments and soils. • Minimise impairment of habitat for threatened terrestrial flora and fauna, and aquatic life forms. • Prevent damage to known heritage resources from post-fire threats, including damage from implementation of mitigations prescribed to protect other values at risk. • Reduce the rate of spread of existing pest plant populations and deter establishment of new, introduced pest plant species. • Mitigate hazards associated with firedamaged dangerous trees. • Identify potential salvage opportunities. • Identify potential for natural regeneration of fire damaged commercial timber stands. • Assess and mitigate the effects of fire and suppression actions to endangered, vulnerable and rare species of flora and fauna. (BAER 2009)

Burnt catchment hydrology Principal concerns for water quality following fire typically include: increased sediment loads, nutrient loads, and heavy metals from soils and geology. The magnitude of post-fire water quality effects are driven by a combination of var iables that include burn severity, slope, geology, soil type, topography, vegetation , land use practices, proximity to water bodies, and runoff events following the fire. Loss of vegetative cover, and changes to soil water repellence, lower infiltration rates and are directly influenced by burn severity. Burned Area Reflectance Classification and Soil Burn Severity

To understand the severity and extent of the burn, the team utilised satellite imagery to develop a Burned Area Reflectance Classification (BARC) map. A BARG map is a map of post-fire vegetation condition, created by comparing satellite near and mid infrared reflectance values before and after the fire. Aerial reconnaissance and field observations were then used to verify and adjust the BARG map to reflect actual burn severity. Areas were categorised into soil burn severity classes from Low to High.

148 FEBRUARY 2010

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Erosion

The adjusted BARG map was used to inform the Erosion Risk Management Tool (ERMiT) model to estimate post fi re erosion hazard probabilities within the burned areas. The hillslope erosion risk is based on soil credibility (soil type and condition), topography (slope, slope length, aspect and shape), soil burn severity, soil exposure (ground cover), and rainfall intensity. Model runs were completed for representative slopes and burn severities. "ERMiT's "event sediment delivery exceedance probability" output can help managers understand the magnitude of erosion potential and the potential impacts of post-fire runoff and erosion on values at risk. Flood Risk Rating

A post-fire flood risk rating was developed for each sub-catchment within the five BAER analysis areas. This rating was primarily based on the percentage of soil burn severity within each catchment, derived from the BARG delineation but were also assessed through field observations, aerial reconnaissance, and generalised catchment characteristics (catchment area, slope, and topography). The post fire flood risk rating of an intense burn of 20% of catchment is equivalent to the post fire flood risk of a moderate burn through 80% of catchment

Recommendations from experience with BAER The BAER team made a series of recommendations to protect the identified values of the catchments studied, with priority given to those areas with high values, and greatest damage potential due to burn severity and erosion potential. This highly effective method of responding to the risk that a post-fire landscape creates; allowing very fast prioritisation of works to reduce the impact that a potential storm event may have to life, property and other assets is one which should be incorporated into the fire planning of all authorities who manage catchments and land. An emergency response team can be sourced from locally available personnel and trained with tools such as the BARG and ERMiT models which are available from the United States Forestry Service.

Simulating this approach locally would allow expedient prioritisation of works and allow for the input of more local knowledge and help minimise the impact of a fire . The tools used by the BAER team are available from the United States Forestry Service.

Conclusion Whilst Melbourne Water's ability to supply water was not immediately affected by the devastating fires of February 2009; the threat of wat er supply contamination and soil erosion from large rain events remains. The paper highlighted the importance of planning for the potential impact of fire and shared the lessons from this experience of major fires. Planning for the potential affects of increased frequency and intensity of fi res due to climate change, should form part of the strategic thinki ng of all potentially impacted businesses.

Acknowledgments Matt Potter and Mario Malovic from the Catchment Management Team and Rob Yurisich of the Strategic Urban Water Planning Team at Melbourne Water who supplied information for the paper.

References BAER Team, Ki/more East - Murrundini Complex South Fire Burned Area Emergency Response BAER Report, March 2009 Bureau of Meteorology (SOM). 2007. Annual Climate summary 2007. National Climate Centre, Bureau of Meteorology, Melbourne. http://www. born .gov .au/climate/annual_sum/ 2007/ index.shtml (March 22, 2009). Bureau of Meteorology Victoria Regional Office,Media Release, 30 January 2009 http://www.bom.gov.au/ announcements/ media_releases/vic/ 20090130a.shtml Hennessy, K. , R. Fawcett, D. Kirono, F. Mpelasoka, D. Jones, J. Bathols, P. Whelton, M. Stafford Smith, M. Howden, C. Mitchell, and N. Plummer, An Assessment of the impact of climate change on the nature and frequency of exceptional climatic events. July 2008 Australian Bureau of Meteorology and CSIRO, 80pp. Lucas C., Hennessy K., Mills G., and Bathols J., Bushfire Weather in Southeast Australia: Recent Trends and Projected Climate Change Impacts September 2007 Bushfire CRC and CSIRO, 33pp. Melbourne Water 2009 Bushfires A Melbourne Water Perspective 2009 Melbourne Water Corporation, 31 pp. Luke, R.H. and McArthur, A.G., 1978: Bushfires in Australia. Australian Government Publishing Service, Canberra. 359pp. Vercoe, T. 2003: 'Whoever owns the fuel owns the fire' - Fire management for forest growers. AFG Special Liftout no. 65, 26(3), 8pp. Melbourne Water Corporation Hydrology Research Papers 1954 - 1991 (available from Melbourne Water Corporation).

technical features


water source protection: incident management

THE 2007 STORM IMPACTS ON MELBOURNE'S UNFILTERED WATER SUPPLY K Hellier, M Stevens Abstract

Storm event in Upper Yarra and Thomson catchments on 27 to 28 June 2007

This paper describes a storm event that had a significant impact on the drinking water quality for part of Melbourne 's water supply. It outlines how pathogen research within Melbourne's catchments and the validation of water disinfection contributed to the successful protection of public health.

The Upper Yarra Water Supply System Upper Yarra Reservoir is located to the east of Melbourne. Water from this reservoir supplies towns in the upper Yarra Valley as well as supplying Silvan Reservoir, which transfers water to most parts of Melbourne. This Reservoir captures water from 34,000 hectares of the protected, forested catchment. The total capacity of the storage is 200,000 ML. Further to the east of Upper Yarra Reservoir is the Thompson Reservoir. It is located in the Thompson River catchment and has a capacity of 1,068,000 ML. Water from Thompson Reservoir is transferred to Melbourne via a t unnel to Upper Yarra. Raw water held in the Upper Yarra Reservoir typically has a turbidity of 13 NTU and Apparent Colour of 6 to 14 pt/co units. E. Coli values are usually below 1 org/100ml. Melbourne Water does not filter water from these pristine catchments, but applies disinfection before reticulation.

The Storm of June 2007 The catchments experienced record drought conditions prior to the major storm event which occurred on Wednesday 27 June 2007. The rainfall ranged from 43mm to 231 mm over the Upper Yarra and Thompson River catchments over durations of about 18 to 24 hours (Figure 1). The resulting combined streamflow of 30 GL over the next 2 days into the Thomson and Upper Yarra reservoirs was the highest on record.

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Figure 1. Rainfall pattern for June 2007 storm event. These streamflows were very turbid due to the drought impacts on the catchment. In addition to the turbid streamflows, Upper Yarra Reservoir was at a relatively low level, being 40% full , with exposed earthen banks.

Incident Management Melbourne Water, as the bulk water supply authority, managed the high turbidity incident in close consu ltation with the drinking water regu lator, the Victorian Department of Human Services (OHS), and Melbourne's retail water companies. Appropriate public health protection measures were jointly assessed. Inspection of the streamflows in the Upper Yarra catchment in the days following the storm event indicated the potential for a major water quality incident in the days following. The turbidity of streamflows in the Yarra River and water transferred from the Thomson River (via a tunnel to the Yarra River) were in the range of 50 to 100 NTU two days after the onset of the storm.

Work to shut off the flow to the Upper Yarra Reservoir from the weir on the Thomson River was initially hampered by fallen trees restricting access to the Thomson catchment. However, this was achieved on 30 June 2007 and reduced the turb idity load and inflow momentum on the Upper Yarra reservoir. Two lake diagnostic systems in Upper Yarra Reservoir transmitted depth profi le information of dissolved oxygen and temperature. Although it was winter, the water in the Upper Yarra reservoir was still stratified t o some degree, assisted by the transfer of colder water from the Thomson catchment throughout the autumn. During the week following the storm , the turbid ity near the outlet ranged from 7 NTU at the surface of the reservoir to 40 NTU near the bottom. Water was drawn from nearer the surface to optimise the quality, however the turbidity of the water supplied from the Upper Yarra reservoir outlet began to increase gradually to between 10 and 15 NTU. To minimise impacts on Silvan Reservoir downstream, which supplies a

water FEBRUARY 2010 149


water source protection: incident management

UV Calcula.ted Dose

Turbidity 25

.-------=~------==---,

250

Transmissivity (%)

100 ---- - - -- - - - - -- - - - ~ ~ - - , 20

90

80 70

·- ., .' : .• •

10

* l

60

+--- - -- ---~- ~ - - --------'!

50 5.000

--Turbidity (NTU) - - -Calculated UV Dose (mWsec/cm2)

10.000

15.000

20.000

25.000

Turbidity (NTU)

Figure 2. UV dose (daily averages) in relation to turbidity for one of Melbourne Water's medium pressure UV plants at Yarra Junction. large portion of Melbourne's water, the transfer of water from the Upper Yarra Reservoir to Silvan Reservoir was minimised. However, the unfiltered supplies to the townships of the Upper Yarra Valley had no better alternative source than the water with the high turbidity from Upper Yarra Reservoir. Therefore, Melbourne Water and the retail water company , Yarra Valley Water, jointly managed the incident with the turbidity of water being supplied to these townships above the Australian Drinking Water Guidelines (NHMRC/NRMMC, 2004) aesthetic limit of 5 NTU. Then during the second week of July complete mixing occurred within the reservoir - which is not unusual for Upper Yarra Reservoir during the winter period. As a result, on Saturday 14 July 2007 the turbid ity in the reservoir rose quickly to about 24 NTU throughout the water column and stayed above 20 NTU for about 10 days (see Figure 2). E.Coli in the raw water was consistently less than 10 orgs/100m l, only slightly above normal levels. This indicated that the bacterial pathogen risk of the source water remained low throug hout. No microbiological excedences occurred during the incident either at customer taps or at Melbourne Water's entry points (after disinfection) to the water supply zones. E.Coli in the catchment streams during the storm event was not measured, but based on previous event based research

150 FEBRUARY 2010

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Figure 3. UV transmissivity (254nm) for Upper Yarra outlet water in relation to turbidity (data from July - August 2007).

in the protected catchments (Roser D. and Ashbolt N. 2007), would probably have been about 100 times higher than the reservoir outlet. This supports the importance of the reservoir detention and dilution as a barrier to contamination. The water quality to the metropolitan area of Melbourne, downstream of Silvan Reservoir, was unaffected except for a significant increase in colour due to the increased proportion of water sourced from the O'Shannassy catchment and other Yarra River tributaries while transfer from Upper Yarra was minimised. This resulted in an increase in the baseline level of complaints within the Yarra Valley Water area of operation. In close consu ltation with the Department of Human Services (OHS) and Melbourne Water, Yarra Valley Water initiated boil water notices for over 6000 customers in the Upper Yarra Valley townships. This notice began on 16 July 2007 because the turbidity entering these areas was considered to be high enough to potentially compromise the effectiveness of the existing disinfection plants As the particles in Upper Yarra Reservoir gradually settled and diluted with clearer water from the catchment the turbidity improved. Criteria for lifting the notice based on decreasing turbidity were established as follows: • Turbidity being less than 10 NTU in the water supplying the townships for a period of more than 7 days, and

• A profile of turbidity in Upper Yarra Reservoir that provided assurance that the turbidity was unlikely to increase significantly above 10 NTU in the short term, thus avoiding a scenario of going out and into boil water notices in short succession, and • Microbiological monitoring of the raw water conti nuing to indicate a low contamination risk, and • Yarra Valley Water confirming that the high turbidity water (i.e. greater than 1O NTU) was flushed out of the reticu lation system. The boil water notices were lifted on 14 August 2007 after the turbidity dropped below 10 NTU. By mid November 2007 the turbidity of the reservoi r was close to normal, that is, below 3 NTU. In response to the incident, Melbourne Water has prepared the capability to provide the townships with a short-term alternative source of water from Silvan Reservoir.

Disinfection Validation The five township water supplies of the upper Yarra Val ley were not filtered and included the following disinfection types: • UV only (low pressure) • UV (medium pressure) and chlorination • Chlorination only. Water quality monitoring was increased during the incident to verify disinfection effectiveness against potential bacterial pathogens.

technical features


water source protection: incident management Melbourne Water's critical limit for effective UV disinfection is a dose of 36 mW.s/ cm 2 , which is consistent with the minimum dose range of 16 to 46 mW.s/cm 2 recommended within the Australian Drinking Water Guidelines (NHMRC/ NRMMC 2004). The UV dose is calculated conti nuously at the two medium pressure plants. There was a close correlation between the increasing turbidity through the UV units and a decline in the dose as demonstrated in Figure 2 confirming that as the turbidity increased above 15 NTU the dose for these plants came close to the critical limits. Melbourne Water's older, low-pressure UV units do not measure dose directly but are designed conservatively t o provide this dose for water with a minimum transmissivity of 50%. The typical UV transmissivity of the Upper Yarra water, with a turbidity less than 3 NTU, is about 90%. The transmissivity of the water during the incident reduced linearly with increasing turbidity as shown in Figure 3

but did not reduce below the 50 % limit for the low pressure units.

adopted a turbidity limit of 15 NTU for effective UV disinfection.

In addition to UV dose and transmissivity, the particle size distribution of the water was determined. The mass median diameter particle size for eight samples taken from the Upper Yarra outlet between 11/7/ 07 and 6/8/07 ranged from 0.16 to 6.0 microns and the 90%ile ranged from 2.5 to 41 microns. The particle size distributions measured were in a range not expected to significantly impact inactivation of bacteria through shielding effects (Liu G. 2007).

Turbidity limits were also developed for chlorination during the incident by Melbourne Water in consultation with OHS.

Some USEPA referenced research (USEPA, 2006) has confirmed effective disinfection for turbidity below 10 NTU but there is little information for higher turbidity. Research by Liu et.al. (Liu G. 2007) found no impact on inactivation of spiked E.Coli into river samples for turbidities between 12 and 32 NTU with particle sizes less than 10 micron. Considering the conservative design of the Upper Yarra Valley UV plants, the measured transmissivities, particle sizes and dose calculations, Melbourne Water

Laboratory tests of E.Coli inoculated samples of the Upper Yarra Reservoir water with turbidities of 14 and 20 NTU that were dosed with chlorine achieved a 6 log reduction after 10 and 20 minutes respectively. This provided a basis for introducing and lifting the boil water notice for the chlorinated Upper Yarra Valley township supply. The same turbidity limit that applied to the UV plants, 15 NTU, was adopted as a conservative limit for effective chlorination also. Therefore, the Melbourne water industry was also prepared with a conservative turbid ity health-limit for the metropolitan water supply if the incident had affected the larger downstream system - which is mostly unfiltered and disinfected with chlorine for the protected catchment sources.

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water source protection: incident management The disinfection val idation information described above for high turbidity applies to the type of particles and water transmissivities resulting from the 2007 storm event. Runoff following a major bushfire event might produce a different profile of water quality which would have to be evaluated at the time of such an incident to confirm the effectiveness of disinfection. Fortunately for the Melbourne syst em, the large storages exist as an important barrier to settle out or dilute the larger particles that have a significant impact on disinfection.

Pathogen Monitoring During the Incident The rainfall and runoff experienced during the 2007 incident was significantly greater than the storm events measured during previous pathogen research. Hence there was a need to characterise the pathogen load and types during the incident and validate previous pathogen risk assessments and catchment research. Although the concentration of bacterial indicators measured out of Upper Yarra Reservoir was low after the storm event, an indication of protozoan risk could not be made due to the potentially greater reduction of E.Coli in the reservoir (over a period of many days) compared with the previous cat chment research.

Quantit ative Microbial Risk Assessment Using a previously established methodology to calculate source loads (Ferguson et al. 2007) the available data on Cryptosporidium loads and genotypes was used to estimate a catchment pathogen budget for the source load delivered to the Upper Yarra Val ley Reservoir during the rainfall event. Th is information was used as an input to calculate the subsequent dilution downstream and the possible exposure scenarios. A quantitative microbial risk assessment (QMRA) was conducted for human-infectious Cryptosporidium. Directly relevant dose respo nse models for non-C. parvum and non-C. hominis genotypes were not available. Human feed ing trials of the genotypes fou nd in the faecal samples in the Melbou rne catchments and from water samples in the water supply system were not available. Therefore, it was assumed that most oocysts were not human infectious but that some were not human infectious but that some were. Based on deer scat samples previous analysed from the catchment it was assumed that 1 in 800 oocysts would be human infectious.

The prevalence of Cryptosporidium in the water samples downstream of Upper Yarra Reservoir identified by microscopy was 28% positive at concentrations between 0.15 and 0.95 oocysts/L. This is a higher prevalence than under normal conditions which is about 5 to 10%, based on a routine monthly water monitoring program.

Predicted risks were not compared to the acceptable risk of 10-6 DALY given in the WHO Guidelines for Drinking Water Quality 2006 since this tolerable disease benchmark represents an endemic disease target. The objective in this case was to establish whether or not the d isease rate would reach epidemic proportions - a "detectable" outbreak. Therefore predicted notification rates were estimated from the QMRA and these were com pared with background rates in Melbourne. The risk assessment predicted that an outbreak would not be seen in Melbourne for the concentration of genotypes of oocysts thought to be present.

Seventy-nine 20L samples were collected during and after the incident for more detailed genetic analysis for Cryptosporidium. One of these samples contained the C.parvum genotype 2 Type A but produced a negative result by microscopy, so although detecting material from a potentially human infectious organism, it was at a low concentration that could not be quantified.

The Cryptosporidium results combined with a quantitative microbial risk assessment were presented to the Victorian Department of Human Services, who determined that t he risk of human infectious Cryptosporidium to the consumers of Melbourne's drinking water was low. As a result a boil water notice for the greater Melbourne area supplied from Silvan Reservoir was not considered necessary.

During and immediately after the incident, a total of 142 water samples of Upper Yarra Reservoir and other local catch ment wat er sources were analysed for Cryptosporidium and Giardia at the Australian Water Quality Centre in Adelaide.

152 FEBRUARY 2010 water

Conclusion and Lessons Learnt The June 2007 Upper Yarra storm event produced the highest inflows to the reservoir on record , and water supply for the Yarra Valley townships became turbid, impacting disinfection effectiveness and resu lting in a precautionary boil water notice to those towns. Disinfection validation information specific to the Upper Yarra system was obtained from this Melbourne Water established a specific public health limit of 15 NTU for turbidity for its unfiltered, prot ected catchment sources - being the point at wh ich the UV dose was red uced near to critical limit s. The experience with pathogen monitoring highlighted the importance of rigorous risk assessment underpinned by research to support water supply management decisions. A key beneficial outcome has been the increased knowledge of water quality associated with the protected catchments and reservoirs with respect to extreme storm events, In particular the Cryptosporidium risk from the protected source wat er did not increase significantly. An important lesson was the value of event sampling of streamflows into reservoirs for future events to characterise the turbidity and microbial load - first bacterial indicators, then pathogens, if warranted. This was not carried out in the 2007 incident and wou ld have assisted in the earlier determination of pathogen risks and more accurate quantitative microbial risk assessment.

References Ferguson C. M., 8. F. W. Croke P. J . Beatson, N. J . Ashbolt, and D. A. Deere. (2007). Development of a process-based model to predict pathogen budgets for the Sydney drinking water catchment. Journal of Water and Health 5(2):187-208. Liu G., Slawson, R., Huck P. Impact of flocculated particles on low pressure UV inactivation of E.Coli in drinking water, Journal of Water Supply Research and Technology. IWA 2007 NHMRC/ NRMMC 2004. National Water Quality Management Strategy: Australian Drinking Water Guidelines. Roser D. and Ashbolt N. , 2007, Source Water Quality Assessment and the Management of Pathogens in Surface Catchments and Aquifers, Research Report 29 of the Cooperative Research Centre for Water Quality and Treatment. USEPA 2006, Ultraviolet Disinfection Guidance Manual for the Final Long Term 2 Enhanced Surface Water Treatment Rule , Nov 2006.

technical features


river health

AUSTRALIA WIDE ASSESSMENT OF RIVER HEALTH N Schofield Abstract Since European settlement, the development of Australia's land and water resources has adversely affect ed river health through: altering flow regimes; decreasing water quality; reducing or impairing ri parian and instream habitat and loss of aquatic biodiversity. Early in the 1990s the Australian Government est ablished the National River Health Program as a response to the 1000 km Darling River algal bloom but also as a first step in slowing and hopefully reversing declining river health. This paper provides a brief synthesis of the history and status of the subsequent national and regional river health assessment processes across Australia, summaries river health assessment results and discusses future issues for river health assessment.

Introduction The origins of interest in river health emerged with the environment al movement in the 1960s, although the term itself did not come into common use until the 1990s. River health as a concept was defined by Schofield & Davies (1996) as 'the degree of similarity to an unimpacted river of the same type, particularly in terms of its biological diversity and ecological functioning. This rather simplistic definition says little of the attributes or behaviour that we might expect of a healthy river but has the advantage of a verifiable, regionally relevant scale against which to measure health. In fact, this is analogous to a general assessment of human health.' This definition was subsequently adopted and adapted into Australia's first major national initiative in river health assessment - the National River Health Program (NRHP). The working definition used for "river health" was: 'The ability of the aquatic ecosystem to support and maintain key ecological processes and a community of organisms with a species composition, diversity and functional organisation as

This review is a highly condensed version of a paper presented to the AWA specialist conference, Canberra, November 2009.

comparable as possible to that of undisturbed habitats of the region ' (Gray 2002, Schofield & Davies 1996, O'Connor, Lloyd, & Moore 1996 after Karr & Dudley 1981). The fi rst phase of the NRH P (19931996) focused on adapting t he UK's RIVPACS scheme to the Australian environment, in what became AusRivAS. In this first stage, referred to as the Monitoring River Health Initiative (MRHI), national bioassessment protocols were agreed amongst all states and territories and capacity was built amongst key practitioners. The second phase of the program (1997-2001) focused on implementing Australia's First National Assessment of River Health (FNARH) at some 5,000 sites across the continent. The results of this assessment were published by the Department of Environment, Water, Heritage and the Arts (DEWHA) in the various State of the Environment Reports (1996, 2001, and 2006), the NLWRA (2000), and on the DEWHA web site at: www.environment. gov.au/ water/publications/environmental/ rivers/index.html. At the time of the FNAR H, it was envisaged that future assessments would be conducted on a cyclical basis (for example, see Gray 2002 [www.nrm . gov.au/publications/factsheets/ me-indicators/inland-aquatic/ river-condition.html]), with results reported 5-yearly in the national State of the Environment Reports , but this did not eventuat e in the manner originally intended. Subsequent national analyses of river health (e.g. National Land and Water Resources Audit (NLWRA 2002), Australian Water Resources (AWR 2005), Australian State of Environment Reports (SOE 1996, 2001 , 2006)) relied heavily on the FNARH (for the aquatic biota component) or additional work of this type supported individually by states and t erritories. Ongoing Australian Government support for national river health monitoring will be req uired if trends in river health are to be identified at a continental scale in the longer term, to both support national State Of Environment (SOE) reporting and to account for expenditure of public funds on river rehabi litation.

Drivers of River Health The anthrogenic factors stressing river health are well-acknowledged, principally agricultural development, urban extraction and discharges, mining, pest control, flow modification by dams, thermal pollution and invasive biota. Perhaps the most concern ing emerging stress on river health is climate change, alongside the already extreme cl imate variability normally experienced in Australia. If all these multiple stresses are being exerted on our rivers, why should we be interested in seeking river health outcomes? This is not a trivial question, as climat e change scenarios are already ordering a re-think of: what are the goals?, what are t he benchmarks and reference points? and what is possible at what cost? As recently as the 1990s, a common reference condition for river health was 'pre-European Australia' . This ideal is now lost in a changi ng climate, as we are forced to accept adaptation as an unstoppable course of events. The paradigm is shifting to 'managing change' rather than attaining esoteric ecological goals. Nevertheless motivations for river health are deeply seated in human emotions, and these are still embodied in community attitudes. We are still shocked to see dried out rivers and wetlands, dying riparian forests and diminishing river-dependent species and populations. The high river health aspirations of the 1990s are giving way in some regions to 'crisis management' driven by insurmountable pressures on rivers, particularly in southern Australia. The paradigm shift from ubiquitous river health to technolog ical ly-supported icon preservation, as evident in The Living Murray, has been extraordinarily rapid.

River Health Assessment The degradation of Australia's rivers has long been recognised but, until the 1990s, there was no coordi nated effort to

A remarkably rapid paradigm shift. water FEBRUARY 2010 15 3


river health monitor river health per se. Since then there has been a series of national processes: In addition there are a number of ongoing, impressive, largescale regional assessments Each program can be accessed through the web-site or reference cited (Tables 1, 2). The reports from these organisations describing methods and resu lts can be accessed in full detail but for the purpose of this shortened paper, the following paragraphs summarise the state of knowledge at the present time.

River Health Impacts The most recent comprehensive Australia-wide report of river health is in SOE (2006). The inland waters theme report assesses river health in six categories: aquatic biodiversity, salinity, erosion and sediments, nutrients, bluegreen algae, and exotic species. The reported results are summarised below and supplemented with more recent regional assessments. Aquatic biodiversity has declined in many river systems since European settlement. For example, one-third of river length in Australia has lost 20-100 per cent of the various kinds of aquatic invertebrates. Conversely, many rivers or river reaches, perhaps the majority, may not be significantly degraded due to a lack of development. Many of them are located in less populated mountain areas or in the northern tropical regions of Australia. Frogs are very sensitive indicators of aquatic ecosystem health and extent. Their populations have decreased markedly in the last decade or so, with 27 species of frog listed as endangered or vulnerable. Riparian vegetation has also declined. Extensive revegetation is required to improve river health, and many areas remain under significant pressure due to the combined impacts of human activity and the drought. For example, in 2003, 80 per cent of remaining River Red Gums on the Murray River floodplain in South Australia were stressed. In lowland rivers, 'de-snagging' and loss of water plants has also modified much instream habitat. River salinity - a third of catchments assessed by the NLWRA (2001 b) showed signs of increased salt loads in rivers and streams. The problem was particularly severe in the southern Murray-Darling Basin, along the south-east coast of Australia, and in catchments in southwest Western Australia . Whether river

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Table 1. National river health assessment initiatives. • National River Health Program (1993-2001) (www.environment.gov.au/water/policy-programs/river health/index.html • Waterwatch Australia {1993 -present) www.waterwatch.org.au • National Land and Water Resources Audit (2002) • National NRM Monitoring and Evaluation indicators (2002) (www.nlwra.gov.au/national-land-and-waterresources-audit • Australian Water Resources (2005) (Norris et al (2007) Assessment of River and Wetland Health: Testing the Framework. National Water Commission) • National State of the Environment Reporting (1996, 2001, 2006) www.environment.gov.au/soe/2006/publications/report/index • National Waterbirds Survey (2009).(www.wetrivers.unsw.edu.au/docs/rp nws.home.html

Table 2. Major state and regional river health assessment initiatives. • Lake Eyre Basin (LEB) River Assessment Program 2005-2009 (www.environment.gov.au/water/publications/environmental/rivers/lake-eyre/assessment.html • Queensland (south-east) Ecosystem Health Monitoring Program (EHMP) 1999-present (www.healthywaterways.org/ehmphome.aspx • Sustainable Rivers Audit (SRA) (2004 to present) www.mdba.gov.au/programs/sustainableriversaudit • Tasmanian River Condition Index (IRC) ongoing (www.dpiw.tas.gov.au/internnsf/WebPages/LBUN4YG9G9?open • Tasmanian Conservation of Freshwater Ecosystem Values (CFEV) ongoing (www.dpiw.tas.gov.au/inter.nsf/Theme Nodes/CGRM-7JH6CM?open • The Living Murray (TLM)2002-present (www. mdba.gov.au/programs.tim • Tropical Rivers and Coastal Knowledge (TRaCK) 2006-present.track.gov.au • Victoria's Index of Stream Condition (ISC).(1999-present) www.dpi.vie.gov.au/DPINro/vrosite. nsf/pages/stream cond index • Tasmanian Waterways Health Monitoring Program • Queensland Aquatic Biodiversity Assessment and Mapping Method (AquaBAMM) • Queensland Stream and Estuarine Assessment Program (SEAP)

salinity has improved is not yet certain because of insufficient data in most places, and there has not been enough time for any significant trends to emerge from the effects of climate variability and variations in flow. There is little evidence that increased salt concentrations have yet had a broad-scale impact on aquatic plants and animals. While adult Australian fish, for example, are generally believed to be quite salt tolerant, research shows that the larval and juvenile stages of certain fish , such as Murray Cod (Maccul/ochella pee/ii pee/ii) are particularly sensitive to salt. Soil erosion and sedimentation throughout Australia soil erosion has significantly increased sediment loads to rivers and estuaries. Extensively cleared catchments, such as large areas of the wheat and sheep zones of eastern and south-western Australia, are worst affected. In many parts of Austral ia, because much of the eroded material has still not yet worked its way through the bigger river systems, large amounts of sediment are stored in river channels in low-gradient areas. Sand slugs in the lowland reaches have smothered various instream habitats, which has had significant impacts on aquatic plants and

animals. Erosion of sediments is dramatically increased after fire. The large-scale fires that burned across south-east Australia caused greatly increased erosion in these areas, leading to poor water quality and the deposition of large amounts of soil and other materials in stream beds and lakes downstream of the fires. Nutrient levels - Excess nutrients were a major water quality issue in about 60 per cent of basins assessed by the NLWRA in 2001. For most rivers, the largest source of increased phosphorus loads is gully and stream bank erosion, rather than farm fertilisers. In contrast, increases in nitrogen levels are typically from fertiliser use, animal wastes and sewage discharges. Nearly 19,000 tonnes of total phosphorus and 141 ,000 tonnes of total nitrogen were estimated to be transported down rivers to the coast each year from areas of intensive agricultural activity. Blue-green algal blooms - blue-green algae have become more widespread as changes to instream habitat and catchment land use have altered the stream metabolism of inland waters. All the changes seem to favour increased toxic algal blooms, and more frequent

technical features


river health periods of oxygen depletion in the bottom waters of pools, weirs and dams.

Exotic species - introduced species appear to be favoured by the large-scale landscape and waterscape management practices fou nd across large areas of the continent. Introduced pests-such as carp (Cyprinus carpio), mosquito fish (Gambusia holbrooki) and oriental weatherloach (Misgurnus anguillicaudatus), and weeds - have continued to expand their range. In the Lower Murray-Darling catchment, for example, exotic species make up 56 per cent of the total biomass of fish. There has been a corresponding decline of native species, with little evidence of effective control of invasive species. Species such as carp not only compete with native species but also alter habitats, and their management is not straightforward. Native fish are more successful in breeding in wet years, and the reintrod uction of environmental flows and overbank flows is needed for ongoing improvement. The AWR (2005) asses sment The Aquatic Biota Index showed approximately one third of the assessed river length was impaired, with almost a quarter having lost at least 20 per cent of the different kinds of aquatic macroinvertebrates that would be expect ed to occur under natural conditions. The environmental components showed that more than 85 per cent of the assessed river length was significantly modified from the original con dition. Nineteen per cent of the assessed river length was classed as substantially modified. New South Wales, Sout h Australia and Western Australia had the greatest percentages of modified river (in terms of environmental features) and the Northern Territory had

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Figure 1. SRA ecosystem health assessments by valley, 2004-2007. the lowest percentage. These figures are likely to be strongly related to both the intensity and extent of land use in each jurisdiction. Norris et al. (2007), applying the FARWH, found changes to catchment land use, fri nging zone and physical form exert the biggest effects on river health; hydrological condition was less important.

Sustainable Rivers Audit Ecosystem health for each valley in the Murray-Darling Basin is determined by integ rating the conditio n indices from all themes using expert ru les.The results are summarised in Figure 1. Only the Paroo Valley was found to be in good ecosystem health.

www.maric.com .au Email: mail@maric.com.au water FEBRUARY 2010 155


river health Lake Eyre Basin Rivers Assessment The rivers and catchments of the Lake Eyre Basin are in generally good condition. In particular, the low level of hydrological modification means critical aquatic ecosystem processes remain intact. Unimpacted aquatic ecosystems make the LES rivers unique compared with other arid river systems in Australia and around the world. The LES may thus provide critical aquatic habitat, especially for migratory waterbirds, given the greater impacts seen in other river systems.

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The ISC benchmarking is completed every five years and has been carried out in 1999 and 2004. The 2004 benchmarking exercise (Figure 2) shows that only 21 % of major rivers and tributaries were in overall good or excellent condition; 32% per cent of river length assessed were in poor or very poor condition. This is due to a combination of factors including changed river flows, poor water quality, poor condition of river bank land, changes to the river channel and reduced habitat. Comparing the ISC results shows that overall at the statewide scale, no major changes had occurred to the condition of Victoria's major rivers and tributaries over the five year period. No general improvement was detected, but conversely overall deterioration in stream condition appears to have been arrested. Streams in good or excellent condition have been identified and protected and those in poor or very poor condition - with only a few exceptions - do not appear to have deteriorated further (as at 2004).

South East Queensland EHMP In 2008-2009, the catchments of South East Queensland received the highest annual average rainfall since the start of the EHMP (1999). This resulted in more flows in the freshwater streams, but also extremely high loads of sediment and nutrients carried from the catchments into the rivers, and then to the estuaries and Moreton Bay. There was no significant change in the overall health of South East Queensland's freshwater streams from 2008 to 2009. Slight improvements in the biological health indicators (aquatic macroinvertebrates and fish) associated with increased flows from the high rainfall were offset by a decrease in the nutrient cycling indicator. The decrease in the nutrient cycling indicator reflects the overwhelming amount of diffuse source pollution entering the streams. Freshwater streams in the highly urbanised catchments of Lower Brisbane, Lower Oxley, and Redland maintained F ratings. The Albert Catchment received an improved grade (8- to A-), indicating excellent water quality. Generally, more native fish species and a lower proportion of alien fish were recorded within South East Queensland 's streams during this period.

The Living Murray Across the southern Murray-Darling Basin, severe drought conditions continue to impact on waterbird communities and limit the availability of other wetland, floodplain and riverine habitats. Most floodplain or shallow icon sites were dry or almost dry and supported few waterbirds and while the main river channel held water it had relatively few birds with low species richness. River red gums and black box continued to decline across all icon sites. Understorey vegetation is suffering with a loss of biodiversity. The overall river condition for fish communities indicated a poor fish population (assessed by a deviation from the Reference Condition). However, new fishways are restoring passage for the migratory fish community and a major resnagging program has increased the available habitat for large-bodied species between Lake Hume and

156 FEBRUARY 2010 water

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Condition Class Figure 2. ISC 2004 results. Yarrawonga. The ecological health of the Lower Lakes, Coorong, Murray Mouth icon site contin ues to decline. The decline is due primarily to the reduction of freshwater inflows.

Emerging Issues Over the last 15 years, the greatest emerging concern has been climate change. Already direct and indirect impacts on river health are apparent from higher temperatures; more intense, frequent and longer droughts; possible cl imate step changes; declining water availability and river inflows; bushfires; rising sea levels; and other extreme events including storms. Southeast Australia is suffering its worst drought on record with devastating impacts on the health of river and wetland systems. A potential link between this drought and climate change has recently been identified, suggesting a permanent, or at least more frequent, drought scenario. The com bination of the drought, climate change (and other factors) initiated a 'water crisis' in Australia in the last decade. The 'water crisis' may be broadly regarded as the sudden and unanticipated significant reduction in water availability in Australia to irrigation, urban and environmental uses. This crisis has been felt across southern and eastern Australia and has in part been related to a 13-year ongoing drought. The water crisis has spawned a massive investment of $12.9b in the Australian Government's Water for the Future program and a similar amount in desalination plants and water grids across southern and eastern Australia. Whilst the policy emphasis on 'water development vs water management' and between 'water quantity vs quality vs ecology' has gone in cycles and continues to do so, currently, as a result of the water crisis, development (e.g. desalination plants, water pipelines, dam building) and quantity (e.g. water sharing plans, sustainable diversion limits, water trading) are foremost in policy development and implementation. The principal current Australian Government activity in river health protection and rehabilitation is provision of environmental watering, including water buy-backs and infrastructure for water recovery. This latter emphasis is driven by both the water reform agenda, the drought, and the collapse of ecosystems in the south. In a relatively short space of time, Australia is apparently undergoing a paradigm shift in river health management. This is most obvious in southern Australia, where 'river health for all' has transformed to 'life support systems', 'triage' and 'saving icons with expensive technological fixes'. In northern Australia rivers are considered relatively unimpacted and climate change

tee n1cal features


river health predictions are more moderate, emphasising an increasing north-south dichotomy. Increasing scarcity of large, intact riverine landscapes globally may enhance the natural values of the north. Other factors likely t o impinge on the health of Australia's rivers include a rapidly increasing population (2.1 % pa); concentration of people in the coast al zone; global food insecurity placing higher demand for irrigated food products; more fervent demand for protection of increasingly scarce ecosystems of high conservation val ue; emergence of indigenous river rights; ongoing implementation of the water reform agenda (including environmental water buy backs); and unknowable technolog ical innovation.

Concluding Remarks • Australia was at the forefront of continent al scale river health assessment in the 1990s but further investment is required in data collection to capitalise on the opportunit y created to provide the capacity for long term national river health assessment. • Identifying long term trends in river health requires a very long term commitment to monitoring in a highly variable and changing climate. • At the national scale, a succession of new, increasingly complex and comprehensive river assessment schemes continue to be devised and trialled. However achieving cost-effective long term continental-scale river health assessments may require using robust, less complex monitoring schemes that focus on ecological impact rather th an riverine and catchment condition. • A number of impressive regional scale river health assessment programs are providing or have the potential to provide river health trends and inform river rehabilitation programs and the wider community. • The success of regional programs includes targetting to local, state or national priorities, local champions, appropriate scales, and strong partnerships. • Climate change and the 13-year drought has induced a remarkably rapid paradigm shift in river management in southern Australia since the 1990s - a shift from 'river health for all' to 'saving icons with technological fixes, life support strategies and triage'. • Environmental wat er buy-backs, record low flows into the Murray River and the perilous state of the Lower Lakes, is focussing river health assessment in southern Australia on maximising ecological outcomes from small environmental water allocations. • Australia's high vulnerability to climate change is viewed with interest

internationally as it grapples with increasing water scarcity. • Future pressures on river health are likely to increase through climate change, increasing population, and increased development. • The differentiation of north and southern Australia around river health is likely to become more marked as northern Australia grows in iconic status and southern Australia suffers increasingly from climate change. • The Australian Government and community, in responding to river health, are likely to question the escalating remediation costs due to the scale of the problem and increasing stresses, particularly if interventions and benefits of public expenditure cannot be adequat ely measured and reported, or improvements do not occur.

Acknowledgments The author would like to acknowledge important comments for a number of river health experts in preparing this paper. The author also recognises the sustained contributions and funding support for river health activities made over the years by the Australian Government, the various stat e and territory governments, NRM regional organisations, researchers, consulting ecologists, and Waterwatch Groups.

References (Gray 2002) [www.nrm.gov.au/publications/ factsheets/me-indicators/inland-aquatic/ river-condition.html]; and Karr, J.R., and D.R. Dudley. 1981. Ecological perspective on water quality goals. Environmental Management 5: 55-68. Norris, R.H., Dyer, F. , Hairsine, P., Kennard, M., Linke, S., Merrin, L. , Read, A., Robinson, W., Ryan, C., Wilkinson, S. and D. Williams (2007). Assessment of River and Wetland Health: Testing the Framework. Australian Wat er Resources 2005, National Water Commission, 59 pp. O'Connor, Lloyd, & Moore (1996) [www.environment.gov.au /water/ publications/environmental/rivers/nrhp/ pubs/review-1996.pdfj Schofield, N.J. and P. E. Davies (1996). Measuring the Health of our Rivers, Water, May/June 1996. [www.environment.gov.au/water/ publications/environmental/ rivers/nrhp/ health-river.html];

The Author Dr Nick Schofield (email nschofield@skm.com.au) is a senior executive consultant with Sinclair Knight Merz (SKM) specialising in water, climate and natural resource management. He was previously Science Manager for Land & Water Australia for 15 years, during which time he managed the fi rst phase of the National River Health Program as well as a number of other river-related national research programs.

water FEBRUARY 2010 157


river health

~ refereed paper

REAL TIME MONITORING OF WATER QUALITY IN RIVERS R Dexter, C Chow Abstract Water quality monitoring has always been limited by the logistics and cost of collecting and analysing grab samples. On line measurements were also limited to a few relatively basic parameters. This paper focuses on new technology now proving itself as a reliable source of a very large amount of relevant data for all forms of water management, both in rivers and reservoirs. A high quality field version of the online UVNis full spectrum spectrophotometer coupled with a modern computer and maths processing has been used in a number of field appli cations in New Zealand and Australia This paper provides case studies to introduce the potential of such data to answer existing queries, highlight unrecognised issues and indicate a pathway for researchers and managers in the water industry.

Introduction Terms Absorption/metre (Abs/m = lab Abs/cm x100). Wavelength Derivative Spectrum (WDS = mathematical derivative of the spectrum with respect to wavelength) Difference from average spectrum (DFA) Historically a limited range of parameters such as pH, temperature, Electrical Conductivity (EC) have been measured in situ and sometimes continuously in key locations on waterways and in reservoirs. Grab or composite samples were collected and tested in the laboratory for a wider range of nutrients and contaminants such as pesticides and heavy metals. The cost of laboratory testing is high, in part due to the range of parameters needing testing. This prevents many t ests which would be nice to have from being financially justifiable. In many cases, unless the variable was present at reasonably elevated concentrations , or a

158 FEBRUARY 2010 water

dramatic change in concentration occurred, events may have passed undetected. In addition, there was only a small chance of collecting a grab sample during a shorter term "event". While pH, EC and temperature data may be useful for many applications, it is inadequate for detecting many of the issues facing water resource managers. This paper looks at the potential to obtain a more comprehensive data set with event-based sampling for lab verification using on-line field mounted UVNis spectrophotometers coupled with advanced mathematical techniques. The challenge is then to find the limits of w hat can be extracted from this new data form. Note that trend plots of parameters such as DOC, nitrat e, colour, turbidity etc are based on calcu lations of "equivalents" from the UVNis spectrum .

Methods All results were obtained using s::can spectro::lyser UV/vis spectrophotometers from Austria in either permanently mounted and powered locations or in portable configurations running off battery packs. Data trends were obtained using scan algorithms supplied with the instruments and validated by DCM Process Control to provide nitrate, DOC, TOC, Turbidity equivalents, calculated from the spectral data. The spectral data plots were produced using custom Matlab software developed by DCM Process Control.

Interpreting the Spectral Data and Spectral Data Images Spectral data images 2,3,4,5 and 9a and 9b need some clarification to make them easily understood. The images are 3 dimensional data plots with the Y axis being the Abs/m which is a fu nction of concentration of various components present. The X axis is the wavelength in

New technology now proving itself for all forms of water quality management.

nm with the UV part of the spectrum represented by the area from 200 to 380nm and the visible part of the spectrum being represented by the region from 380 to 730nm. The Z axis is time. Different solutes wi ll be represented by absorptions in appropriate areas of the UV spectrum, for example nitrate, which has its maximum absorption around 210nm . The intensity of the absorption is a quantitative measure of the concentration of the compound. The absorption spectrum obtained in the field will be the sum of all compounds that have some absorption at that frequency. For this reason , the majority of spectral images presented here have had additional math processes applied so as to recalculate the spectra as a difference from average or as a wavelength differentiated spectrum. These forms allow specific components of the raw spectrum to be extract ed via mathematics rather than physically as would normally be done via a separation column in a laboratory situation. Spectral images that are seen as 2D images are 3D images rotated into 2D to c larify some aspect. ( see plots 9a and 9b.) Various other forms of the spectra are the mathematical wavelength derivative of the entire spectrum. The spectral data plots in Figures 6 and 7- are simple subtraction spectra in the same way that a lab UVNis spectrophotometer essentially subtracts the spectrum measured from a zero reference spectrum. All that changes in these plots is the "zero" that we have chosen to subtract the spectrum from to provide the detail required.

Case Studies Th ree case studies from NZ and Australian waters covering a range of applications are presented. Confidentiality issues prevent sites being identified in some cases.

Case Study 1 - Understanding River Dynamics. Two locations on a large river with a lake source have been monitored over a

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Plot 1a. Calculated equivalents for DOC, Turbidity, nitrate and TOC from upstream site. significant period using full spectrum UVNis spect rophotomet ers running o n a 2 minute measurement interval. The locations are about 100 km apart, with numerous tributary streams entering the river along this distance. These tributaries drain intensively farmed areas. In addition, some discharges from dairy and meat processing facilities are also present The data in plot 1a and b shows the general trend in absorption values at these two points. The Upriver point has far lower concentrations of components that absorb in the UVN is spectrum which includes many organics and nitrate. This is reflected in the scales used in the plots. The event not ed as a single peak in upstream data (River 160) and a double peak in the downst ream data (River 290) are al l caused by the same rain event which fell as a broad band moving from dow nstream to upstream. This explains the time difference between the peak on Friday/ Saturday in the River 160 data and the earlier sharp peak in the point 290

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data. The event noted in the River 290 downstream data at midday on Sunday is the result of the upstream flow from t he peak in River 160 reaching the River 290 point hours later. The river has a speed of greater than 1 m/ s over much of its length. This time difference had already been determined by a large number of events seen in the data over a period of more than 2 years. This then allows us to study the changes in components and concentrations as the material progresses down the river. Short term sudden shifts in solids as seen on the Monday and Tuesday in Plot 1 b indicate events very close to the measuring point and are unlikely to represent w hole of river events. The diurnal variation had been noted previously by grab sampling, The spectral data indicate that the variation is primarily driven by dilution by the varying flows discharged by upstream hydro stations (to match power requirements) with some smaller concentration changes caused by the river ecology. A dilution driven change from a clean source would affect almost all

components in the spectrum whi le a biological change wi ll see an increase in the nitrate spectral absorption during the day as the river biology reacts to sunlight and oxidises ammon ia, with a small correspondi ng reduction in some organics and a rise in others as they are consumed or released by t he biomass. In Plots 2 to 5, the nitrate, which absorbs directly in the UV spectrum, can be considered to be the major contributor to the red/orange coloured components. The data in Plots 2 to 5 below show summer and winter spectral images for the two river locations in Plots 1 a and b. They show that the degree of dilution and biologically driven change varies over the year. There is more biological activity during the warmer summer months, however, the main driver of the visible change, especially in winter, is dilution. In winter t he temperature is lower and sunlight hours reduced w hich slows biological changes. Higher winter power use results in more flow and more flow variation t hrough hydro stations creating a larger dilution factor in the d iurnal variation.

water FEBRUARY 2010 159


river health Plot 2 shows a distinct offset between t he deep UV components and the rest of the spectrum as seen by the rise in the blue components while the red yellow components fall i.e. partly dilution and partly biological. Note the variation overall is 0.6 to -0.6 Abs/m. The plot shows a greatly reduced offset between changing concentrations of components indicating reduced biological activity. The overall shift in absorptions is approx 60% greater than during summer which fits a higher flowrate change from hydropower production.

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A range of changes can be seen to occur in Plot 4 during the summer over a

time relati ng approximately to that seen upriver in Plot 2. Greater overall variation occurs as many more sidestreams enter between the two measurement locations. The dat a from winter clearly shows a substantial change in concentration of various components with an almost exclusively dilution driven change in concentrations. Extensive further studies will be possible in the future with data from both of these measurement locations and hopefully with more monitoring stations along the river. Data can be automatically downloaded and processed to include spectral subtractions. The output is then the difference in components between the two locations without the confusion of the background material present at the upper measuring station. The ongoing cost for a substantial increase in output wi ll be minimal com pared to historic techniques. The intent is to be able to rapidly detect spills into the river by the huge variety of users of this water source in addition to detection of inputs from sources such as a recent incident with a truck tipping over on a river bridge and losing its load into the water.

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for a period during the 20 minutes or so spent at each location undertaking other t ests. The unit was directly submerged in the waterway by cable tying to a pointed metal pole pushed into the streambed out from the bank.

points. A normal study involving parameters such as DOC may or may not show the ingress of a new dissolved organic component clearly as the stream river itself is actively removing organics of various types while others are being added. Here we have the opportunity to essentially compare full spectra between each test point which in this case gives us 256 discreet measurements to determine changes in composition not just concentration.

The key in this study was to find out what difference there was between the water quality at various points along the river from the lake source to the ocean outfall beyond the mill intake/discharge

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A pulp mill discharging treated waste into a waterway has a river boundary bordering the mill operation. Monitoring by regulators is based on several standard parameters including black spot visibility testing and comprehensive laborat ory testing of water quality. The regu lar river survey of a number of upstream, mid mill and downstream water testing points was augmented by use of an on-line UVNis spectrophotometer run off a battery pack

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The spectral data from the UVNis spectrophotometer is shown in several forms. The spectra in Plot 6 are subtraction spectra with the reference being the lake water. This means that the spectra shown are the material that has come into the river since the water left the lake only, with no "background" of the lake water components. The spectra show a clear increase in the organic levels in the river with a shift in components noted particularly in the 280nm band. Interestingly, some components appear to be removed between the downstream measurement point and the ocean outfall. This is likely to be biological in nature and a further study as with Case 1 would confirm t his. In this plot the same raw spectra have been treat ed differently. Rather than using the Lake outlet spectrum as a reference the measuring point above the current point is used as a reference. The changes occurring only between those two points is not visi ble spectrally. This approach is totally val id as the spectrum is a primary standard and an absolute measure of the sum of the components absorbing in this spectral region.

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sampling point 2 and 3 along the mill river boundary. Neither of these shifts were previously known or recog nised. There is by far the largest shift after the mill waste enters the river however this also includes some river boundary with dairying operations. The composition is seen to shift here in many areas of the spectrum including

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Water Infrastructure A Tyco International Company GROUP water FEBRUARY 2010 161


river health

~ refereed paper

into the lower end of the visible spectrum above 380nm although this is small c ompared to the organic shifts. A fourth negative change is seen in the final point between the downriver and ocean outfall points. It is clear that certain compounds entering via the mill discharge are being removed by the river between these points which are a number of Km apart.

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It is also important that it does accept responsibility for inputs which may be coming from sources such as leaching from open chem ical/wood storage or possibly from its geothermal power system as seen between points 2 and 3. Since the spectra here effectively represent the spectra of the components we are looking for, testing and identification can be inexpensive and rapid as a simple UV spectrum of suspected sources is all that is needed. It is hoped that such data can be used as an effective monitoring and management tool in the future.

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Case Study 3 Protecting Drinking Water Sources and Comparing Components.

Drinking water and other use of river sources create a myriad of potential issues where many stakeholders have access to river for intake and discharge. A large and long inland river acting as a

water source for a large city based near its mouth has to deal with many such issues. Extensive agriculture along its length, extensive public recreational use, plus the presence of many upstream municipal and industrial sources

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Plot 9a and b. WDS spectral data from two separate sites. 162 FEBRUARY 2010 water

discharging into its waters results in significant potential for chemical spills and low level residues to be present. The use of such water therefore relies on sufficient timely testing. The rivers trend plot, Plot 8, shows relatively little variation in key paramet ers over the one week period with the exception of the event seen on Wednesday 26th Sept ember. Note that the sharp rise of the event and tapered fall off is typical of plug flow events in waterways. The further from the source t he less clearly defined the rise and more tapered the fall in values is likely to be. A rain event on the river, which has a huge catchment, would produce a clear shift over a long time period which is not seen here. The Turbidity, Nitrate, Colour and DOC trends indicate that it is a short term event from a close by source. It is likely to have come from a discharge from a source in the small town a 0.5 Km upriver. Apart from stormwater there are other legal

technical features


~ refereed paper

river health

and suspected illegal discharge points which are generally unmonitored. Interestingly the nitrate and alarm parameters indicated the event was present before the turbidity rose. The alarm parameters indicated that the event was not severe enough to operate an intake shutdown, which would occur at 1 or + 1 boundaries. A deviation to either boundary from the locally determined normal ( 0) initiates an alarm output.

trying to guess what could be there and constantly reprogramming to add every possible new contaminant. Contaminants can come from spills of diesel or petrol from river craft and filling stations on the river, from pesticides and herbicides used in agriculture along the rivers path (ref the recent Tasmanian event with the herbicide hexazinone used in forestry operations) or from disasters that may result in any combination of chemicals being present (ref the Sandoz fire affecting the Rhine in Germany).

The spectral data from this river is seen to be quite different from other lowland rivers studied. Plot 9b which is from a forested catchment with stock operations for a relatively short length of river upstream also exhibit significant changes from their source waters, however they rarely exhibit the complexity seen in Plot 9a. Plots 9a and 9b are both wavelength derivative spectra which have been inverted for ease of viewing.

The availability of systems capable of supplying such huge amounts of data and the ability to make sense of the data provided has the potential to radically rethink the way we currently regulate and sample. If such systems become an integral part of the monitoring network or our rivers and reservoirs, there is likely to be a shift from traditional sampling to event based sampling, with investigate studies to find specific causes being far more common and cost effective.

In Plot 9a there are 9 days of spectra at 2 minute intervals from the time period from the 24th Sept to the 3rd Oct overlaid on top of each other. Plot 9b has about half that number in the plot from 19th to 24th Sept. The consistency in the composition of both rivers is easy to see.

The ability to utilise full spectrum UVNis field mounted devices coupled to modern computing and mathematics clearly allows a far greater inherent understanding of water composition and the changes in composition that occur over time. Measurement of the full UVNis spectrum at any one point on a waterway has the potential to vastly increase our understanding of water composition dynamics and to detect previously unrecognised compositional events.

The measuring point is set up to utilise not only alarms based on individual specific parameters but on spectral deviation from normal. This is a very sensitive yet simple solution rather than

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The use of full spectrum UVNis spectrophotometers at multiple points along a waterway provides not on ly a

Acknowledgments Thanks to those authorities allowing data to be used for research purposes.

References Chow, C. , Sweet, V., Adams, K., Mosisch, T., Shephard , M. and Dexter, R. , Implementation of a Real Time Early Warning System for Water Quality Incidents, OzWater 09, AWA, Melbourne Convention and Exhibition Centre, Melbourne, 16-18 March, 2009 (platform).

The Authors

Rob Dexter is Director R&D for DCM Process Control, Auckland/Melbourne (rob@dcmprocesscontrol.com).

Dr Chris Chow is Senior Research Chemist at the Australian Water Quality Centre and Adjunct Associate Professor, SA Water Centre for Water Management and Reuse, University of South Australia.

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Such devices provide a pathway to greatly reduce the amount of routine lab sampling and replace it with specific investigative testing capable of rapidly producing required outcomes.

Conclusions

The event seen in the data trend in Plot 8 on the 26t h Sept is visible as a broadening of the 2D spectrum in Plot 9a in several areas of the spectrum below 240nm and between 270nm and 350nm. In contrast 9b shows almost no variation other than a minor one in the very deep UV where no event occurred. The greatly reduced complexity of 9b is related to the upstream catchment.

~

wider data window of aspects monitored at any single point, it enables subtraction spectra to be calculated to identify minute compositional changes unlikely to be detectable in a single system.

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163


river health

FINDING A WATER BALANCE FOR COTTON PRODUCTION A Kay With the recent unfortunate news that Cubbie Station has been placed into receivership due to years of prolonged drought, issues of water reform and government water buy backs have again been raised in the public arena. Cubbie Station and the Australian cotton industry have been exposed to years of media criticism and blame over the state of the Murray-Darling river system, with often little sense of balance in this reporting. Extreme views such as calls to ban cotton growing in Australia or that a single farm enterprise can significantly impact on an entire river system grab headlines but do nothing to assist in negotiating political or practical solutions. The discussion of how we efficiently and sustainably use our water resource is clearly too important to our national economy (not to mention hundreds of regional communities) to be reduced to three-word headlines. The higher the quality of public discourse on these matters - the higher quality policy response we will receive. We must remember that everyone is looking for the same broad outcome: a balanced and sustainable distribution of a limited resource that allows the health of our natural environment, our cities to drink, our food and fibre to be grown and our regional communities to prosper.

clearly showed that natural fibres are a better choice for the environment. Cotton is ideal for Australia's variable climate because it is an annual crop that is only grown when water is available. No water, no cotton. Wentworth Group Scientist and Water Economist, Mike Young agreed when he said "Australia has one of the most variable water supply systems in the world, and to manage it we need annual crops that can be switched on and off depending on how much water is available." Unfortunately, the continuing drought has seen cotton production dramatically fall compared to pre-drought levels, with the 2007/08 crop the smallest in 30 years due to a lack of available water. This has had severe flow-on effects in regional communities that have traditionally relied on cotton production for their economic and social livelihood. One study on the small town of Wee Waa in North Western NSW showed permanent staff numbers fell 60% between 2004 and 2007 and two-thirds of employees who lost their jobs left the region. Arguments t hat rely on the principle that if we "ban cotton more water will be delivered to the system" are severely flawed.

Australia's cotton industry is the most efficient in the world. Our growers produce high-quality natural fibres in huge demand on the world market with less water and a smaller environmental footprint than any of our cotton competitors. This view was echoed by John Williams, Natural Resources Commissioner in NSW, in a recent ABC radio interview. The alternative is either cotton produced in countries with a far greater environmental footprint, or an increased reliance on synthetic fibres such as polyester and nylon. A recent lifecycle analysis of the carbon footprint of a cotton t-shirt compared to a synthetic version (funded by the Australian cotton industry)

Table 1 Average Irrigation Requirement (megalitres per hectare)

Rice Lucerne for hay Sweet corn Asparagus Watermelon Tomatoes Maize Cotton Soybeans Sugar cane Pasture for grazing

The national debate needs balance and factual evidence.

Technology

8

8

8 7.15 6.3 6 5 4

Source: ABS Water Use on Australian Farms 2005-06 and NSW Agriculture Farm Budgets 2006

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river health The purchase and subsequent rehabilitation of "Burrima", a property in the middle of the Macquarie Marshes that was acquired by a group of farmers in 2005, clearly shows that land management plays a critical role in their health. Graphic evidence has been collected showing that even during drought with little available water, the exclusion of stock and the implementation of sustainable land management techniques can have a dramatic positive impact.

The Macquarie Marshes Nature Reserve on the right and privately owned marshes on the left of the fence. The nature reserve contains only 10% of the Marshes. The management of the land, not water, has been shown to be a key driver of wetland health. Picture by Peter Solness/MDBC.

Sustainable access to water is central to our industry's ongoing ability to support 10,000 jobs and generate $1.2 billion each year for the national economy. It is for this reason that Cotton Australia strives to get balance and factual evidence on the tabl e in this critical national debate.

The Author Not only is cotton not the biggest water user in agriculture (dairy farming is, with 19 % followed by livestock and grains at 18%, cotton 15%), it is a very drought and heat-tolerant plant that does not require excessive amounts of water.

north-west NSW), 20% of the total water entitlements have been purchased by the Australian government to date. However the environmental assets attached to this water, the Gwydir Wetlands, are 100% privately owned and unless they are managed with conservation values in mind, the acquisition of this water will be a huge waste of public money.

Far from being "thirsty" , the cotton plant is highly efficient in turning water into fibre and uses about the same or less water per hectare as other summer crops, as Table 1 clearly shows. Cotton Australia's longstanding policy has been to insist on fu ll transparency and market price for any water buybacks and that they on ly be from wi lling sellers. At every opportunity Cotton Australia has sounded warnings to Govern ment on the impact of permanently removing irrigation entitlements from basin communities whose social fabric and economic foundations are based on irrigated agriculture. The purchase of environmental water has seen little focus on how and when this water wi ll be injected into the natural environment, how water wil l be managed on private land and how results will be measured. Nothing wi ll be achieved if delivery of environmental water is undermined by poor land use practices on privately owned natural assets. In the Gwydir Valley (a major cotton producing region in

A similar case exists with the iconic Macquarie Marshes in NSW, of which only 20 square ki lometres out of a total 200 are in nature reserve (the rest is privately owned, mostly grazing land).

Adam Kay has been the CEO of Cotton Australia since January 2007, and has spent over 20 years working in rural and regional Australia. He was awarded the 2005 Australian Cotton Industry Service to Industry Award , is a Churchill Fellow and a Graduate of the Australian Rural Leadership Program. Email adamk@cotton.org.au.

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water FEBRUARY 2010 165


river health

REPLACEMENT OF ENVIRONMENTAL FLOWS IN THE HAWKESBURY-NEPEAN RIVER M Griffith, S Biddulph Abstract The Replacement Flows Project (the Project) is a key component of NSW Government Metropolitan Water Plan. It is part of a long-term strategy to increase the amount of wastewater being re-used for beneficial purposes. The project is designed t o save drinking water and maintain river health. It wil l provide highly treat ed recycled water to the Hawkesbury-Nepean River system, augmenting water currently released from Warragamba Dam t o maintain riparian and environmental flows. Approval of t he Project was granted by the NSW Department of Planning with several statutory environmental conditions, including the design and implementation of an environmental assessment program. A key environmental question posed during the approval process was related to the high level of treatment required to produce the recycled water: what effect on the aquatic ecology of the receiving waters does the introduction of very low mineral content (low conductivity or salinity) recycled water have? Research into the influence of low conductivity discharges on freshwater environments is limited and is a unique technical and reg ulatory challenge. The combined results from a suite of aquatic toxicity bioassays, a conductivity dispersion study and hydrodynamic modelling indicate that aquatic life in the Nepean River is unlikely to be adversely affected by the recycled water discharge. A minimum conductivity value of around 120 ÂľSiem was identified via the bioassays to minimise the likelihood of osmoregulatory stress in exposed aquatic organisms. The Nepean River in the vicin ity of the discharge is expected to have conductivity in excess of 120 ÂľSiem once thoroughly mixed with the recycled water, and be within the Al\!ZECC range for lowland rivers of South Eastern Australia. This paper focuses on the environmental and laboratory

166 FEBRUARY 2010 water

Figure 1. Replacement Flows Project location map.

investigations Sydney Water is undertaking to evaluate the likely influence of the recycled wat er environmental flow on the HawkesburyNepean River and its biota.

Introduction Wastewater recycling can make a significant contribution to securing sustainable water supplies. The Metropolitan Water Plan, Sydney's

Assessing the influence of low conductivity recycled water on freshwater aquatic biota.

long-term plan for water supply, includes maximising the use of existing dams, providing water sources independent of rainfall through desalination and increased recycling, and improved wat er efficiency in both the community and business areas. These four component s constitute the NSW Government's Water for Life program. Recycled water can deliver multiple benefits. For instance, it can reduce the demand on the drinking water system by offsetting potable water draw-down, reduce the level of nutrients discharged by sewage treatment plants (STPs) into rivers, and moderate the impact of future droughts by reducing pressure on rain fed storages (NSW Government 2006).

technical features


river health Sydney Water already recycles a significant amount of wastewater in a number of residential, industrial and agricultural projects to directly offset potable demand. By 2015, the volume of recycled water use will be approximately 70 billion litres every year.

Hawkesbury-Nepean River

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Highly treated recycled water , - . . - - - 50 MUday

The Western Sydney Recycled Water Initiative (WSRWI), which forms part of the Metropolitan Water Plan has been put in place to help secure Sydney's water supply needs by maximising the beneficial use of recycled water for residential, irrigation and environmental uses. A key element of the WSRWI is the Replacement Flows Project.

Penrith

STP

Background

St Marys

STP

This Replacement Flows Project has the potential to save up to 18 billion lit res of drinking water currently released from Warragamba Dam each year for environmental flows into the Hawkesbury-Nepean River system. Th is will be achieved by providing high quality recycled water t o the Nepean River to reduce current releases from Warragamba Dam. Changed environmental flow releases from the Upper Nepean dams as part of the broader Metropolitan Water Plan will maintain flow in the Nepean River upstream of Penrith Weir.

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Quakers Hill

STP NSOOS 8 MUday

Figure 2. Replacement Flows Project (Sydney Water 2006).

The recycled water will be provided from an Advanced Recycled Water Treatment Plant constructed at St Marys in Sydney's western suburbs. The project will deliver environmental benefits to the river by subst antially reducing the input of nutrients (particularly nitrogen) from the three largest STPs currently discharging into the HawkesburyNepean River system and South Creek (Figures 1, 2).

The plant will use ultrafi ltration followed by three-stage reverse osmosis (RO) membrane technology (Figure 4). The fi nal recycled water will receive pH adjustment, breakpoint chlorination and dechlorination before transfer to Penrith STP and discharge into Boundary Creek. As a by-product of the high level of treatment, approximately 8 MUday of concentrate from the reverse osmosis process is produced which will be discharged to the Northern Suburbs Ocean Outfall System (NSOOS). Construction of the treatment plant began in May 2008. The commissioning of the plant is expected at the end of 2009, and is scheduled to be operational from mid-2010.

Advanced Recycled Water Treatment Plant Technical Specifications The Advanced Recycled Water Treatment Plant is being constructed adjacent to the St Marys STP in Western Sydney (Figure 3). The treatment plant will provide further treatment of tertiary treated effluent sourced from St Marys, Quakers Hill and Penrith STPs and produce up to 50 MUday of highly treated recycled water. The recycled water wi ll be transferred directly to Boundary Creek, which flows into the Nepean River downstream of Penrith Weir. Boundary Creek is an ephemeral stream that, during dry weather, transports only treated sewage discharges.

A recycled water pilot plant was built to test the treatment technology and monitor its performance. The pilot facility was located adjacent to existing infrastructure on the St Marys STP site and was designed to mimic as closely as possible the process and resu ltant recycled water quality of the fully

Concentrate recovery Concentrate recovery

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water FEBRUARY 2010

167


river health commissioned t reatment plant. The pilot plant operated for a four month period ending in Decem ber 2008.

Assessment of Environmental Pe rformance A statutory requirement of the plann ing approval for the Project required Sydney Water to verify t he environmental performance of the treatment plant (Department of Planning 2007) and address specific environmental questions. A comprehensive Aquatic Environmental Assessment Program (Syd ney Water 2008) was designed and implemented. The monitoring program was developed by Sydney Water in consultation with relevant NSW Government stakeholders. The monitoring program has the following broad objective: "To provide a comprehensive and robust program of baseline and postcommissioning monitoring of aquatic environmental conditions to assess receiving water impacts that may arise from the Replacement Flows Project."

The Environmental Monitoring Program The monitori ng program uses robust statist ical methods and embraces t he principles of the ANZECC (2000) Fresh and Marine Water Quality Guidelines. T he

core components are broad ly based on the Multiple Before After Control Impact (MBACI) design, which includes multiple measurements at bot h test and control locations before and after comm issioning of the recycled water plant. Test sites have been chosen at locations where change associated w ith the operat ion of the t reatment plant is expected i.e. downstream of t he recycled water discharge on both Boundary Creek and the Nepean River, and downstream of St Marys and Quakers Hill STPs on South and Breakfast creeks, respectively. Control sites have been chosen at locations that are not expected to change following operation of the plant i.e. upstream of the d ischarge on both Boundary Creek and t he Nepean River and upstream of the St Marys and Quakers Hill STPs . St atistical comparison looking at 'before' versus 'after', and 'test' versus 'control' results wil l identify if an impact or change has taken place in response to the discharge of recycled water.

2) observational support studies to examine gross changes in fish and macrophyte comm unities when potentially confou nding factors may affect the statist ical abil ity to det ect changes. Incorporating two types of before/after studies, (statistical and observational), and including a combination of physical, chemical and biological components, provides a weight-of-evidence ap proach to assessing impact. Using multiple lines of evidence increases the level of confidence in the findings from the individual studies and recognises the linkages between the variables within an ecosystem .

The monitoring program includes two types of before/after studies: 1) impact assessment where several discrete studies aim to measure statistically significant changes in t he receiving water environment - focusing on the analysis of water q uality, effluent quality and macroinvertebrate data; and

T he monitoring program wi ll address the requ irements set out in the Environmental Assessment Report (Sydney Water 2006) as well as verifying the predict ions of the environ mental benefits. The baseline studies w ill span a period of up to two years and post commissioning studies a period of three years. Sydney Water also has ongoing compliance monitoring programs that complement the key requirements of the monitoring prog ram. In many cases, Sydney Wat er's compliance prog rams have generated datasets that extend from 1995. This data will great ly enhance the establishment of baseline conditions for the Hawkesbury-Nepean River

Table 1. Aquatic Environmental Assessment Monitoring Program. Number of sites

Frequency

Pre Commissioning (baseline)

Control

Test

3-4 weekly

7

8 4

Up to 2 years (2008-2009)

Mar-May

June-Aug

Sept-Nov

Dec-Feb

Water quality - nutrients, bacteria, chlorophyll a, algae

3-4 weekly

3-4 weekly

3-4 weekly

Effluent quality

nutrients/bacteria

every 6 days

every 6 days

every 6 days

every 6 days

na

metals/toxicity

monthly

monthly

monthly

monthly

na

4

7

8

4

5

Macroinvertebrates

6 monthly

Fish

3 monthly

Macrophytes

6 monthly

6 monthly 3 monthly

3 monthly

3 monthly

6

6 monthly

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Post Commissioning Control

Test

3-4 weekly

7

8

3 years (2010-2013) Water quality - nutrients, bacteria, chlorophyll a, algae Effluent quality

nutrients/bacteria metals/toxicity

3-4 weekly

3-4 weekly

3-4 weekly

every 6 days

every 6 days

every 6 days

every 6 days

na

4

monthly

monthly

monthly

monthly

na

4

7

8

4

5

Macroinvertebrates

6 monthly

Fish

3 monthly

Macrophytes

6 monthly

6 monthly 3 monthly

3 monthly 6 monthly

3 monthly

6

-----------------------------------------------------------------------------------------------------------------na samples collected from treatment plant post commissioning recycled water Recycled Water bioassays (algae,

12

------na

water flea, mussel, fish, duckweed}

Note: historical data will also be incorporated where relevant

168 FEBRUARY 2010 water

I

technical features


river health system. Table 1 outlines the key components of t he monitoring program.

Recycled Water Conductivity and its Potential Impacts: A Unique Element of the Program A question posed during the environmental assessment process was whether or not the recycled water may be too pure to support aquatic organisms in the receiving waterways. This was specifically related to the very low mineral content (i.e. low conductivity) of the recycled water. Conductivity is often used as a surrogate measure of the collective concentrations of common ions (salts) in freshwater. The highly treated recycled water produced from the treatment plant has a very low conductivity because of the reverse osmosis treatment process which removes nutrients, minerals and salts from the water. The recycled water has the potential to induce stress (toxicity responses) in aquatic organisms inhabiting the receiving waters through the imbalance between the normal composition of ions within the cells of aquatic organisms and the low concentrations of ions in the recycled water discharge. The internal fluids of most freshwater organisms have higher ion concentrations than the surrounding aquatic environment. Thus there is a tendency for water to move continually into body tissues of aquatic organisms and ions to move out of the body. Aquatic organisms have developed a number of physiological mechanisms to balance the water and ion concentrations of their body fluids. A great deal of metabolic energy is used by most aquatic organisms regulating their water and ion content, a process known as osmoregulation. Changes in the concentration or composition of ions in the surrounding water can cause an organism to expend too much energy trying to regulate the composition of their internal fluids. This may result in chron ic stress affecting important fu nctions such as growth and reproduction. Sudden changes in ion concentration or composition can sometimes result in mortality. As part of the Project, Sydney Water endeavoured to assess the hazard posed to freshwater biota by exposure to treatment plant recycled water using a suite of aquatic bioassays. The bioassay suite was comprised of several different freshwater species representing a range

Table 2. Summary of bioassays. Group

Test organism and exposure period

Bioassay test type

Algae Green algae (Pseudokirchneriella subcapitata) 72-hour exposure Crustacean Water flea (Ceriodaphnia dubia) 48-hour exposure Crustacean Water flea (Ceriodaphnia dubia) 7-day exposure Mollusc Freshwater mussel (Velesunio ambiguus) glochidia 24-hour exposure

Chronic 1 (growth) Acute2 (immobility) Chronic (reproduction) Acute (survivorship)

Fish Larval Australian bass (Macquaria novemaculeata) 96-hour exposure Sub-lethal3 Fish Juvenile Australian bass (Macquaria novemaculeata) 14-day exposure Chronic (growth) Macrophyte Duckweed (Lemna minor) 7-day growth test Chronic (growth) 1 Chronic

toxicity implies long-term effects that are related to changes in metabolism, growth, reproduction, or ability to survive

2

Acute toxicity is an adverse effect (lethal or sub-lethal) induced in the test organisms within a short period of exposure to a test material, usually a few days

3

Sub-lethal means detrimental to the organism, but below the level that directly causes death within the test period

of taxonomic groups, incorporating sensitive life stages and a combi nation of short term and long-term test endpoints (Table 2). Six bioassay methods and four test species were used to characterise the effect of recycled water obtained from the pilot plant on aquatic organisms. The test organisms included a green algae, a crust acean (wat er flea), a

mollusc (freshwater mussel) and a fish species (Australian bass). Testing was undertaken using a range of conductivity levels - 100% recycled water at a conductivity of approximately 20-40 µS/c m, and treatment groups created by mixing the recycled water with Nepean River water to achieve conductivities of approximately 75, 120 and 175 µSiem .

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169


river health Subsequent to this, a macrophyte {d uckweed) bioassay was added to the program as an indicator of the potential effects of the recycled wat er on aquatic plant species. The tests focused on a lower range of conductivity levels using knowledge gained from the previous bioassays {20 µSiem (100% recycled water) through to 120 µSiem). By observing the responses of a range of aquatic organisms following their exposure in the various conductivity treatment groups, it was possible to identify critical conductivity thresholds above which adverse effects did not occur. In this manner the proportion of recycled water to river water at wh ich no observed adverse effects on the aquatic organisms exposed could be established. This suite of tests was repeated on three occasions to verify the findings (Table 2).

Findings from the Recycled Water Conductivity Study During the conduct of the bioassay experiments there were practical issues associated with the use of standard USEPA test protocols with green algae and duckweed which required the addition of media. Consequently the result s of both the green algae and duckweed bioassays are considered t o have a high level of uncertainty associated with them. Overall the results generated using the bioassay suite indicate that exposure of the test organisms to the 100% recycled water (conduct ivity of 20-40 µSiem) treatment c aused adverse effects on all organisms tested, with the exception of the mussel (d uring a 24-hour exposure period). Upon mixing the recycled water

ANZECC lowland river guideline minimum

-

48-hour flea Acute

24-hour mussel Sub lethal

96-hour fish 14-day fish

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7-day flea Chronic

7-day duckweed

••

72-hour algae 0

20

40

60

80

100

120 140 160 180

200

220 240 260 280

Conductivity (uS/cm) (NB• insensitive to low conductivity stressor, •• uncertainly associated with result)

Figure 5. Lowest concentration at which no adverse effects occurred (photographs by Ecotox Australia and Sydney Water Aquatic Ecology Group).

with Nepean River water to raise its conductivity, the observed effects were reduced. These results indicate that as conductivity increases, the potential for osmoregulatory stress in the exposed aquatic organisms decreases. Confirmatory toxicity tests were then conducted using the water flea to ensure that the adverse response observed was not due to the presence of any residual chem icals (i.e. toxicants) that had passed through the treatment processes or were present in the Nepean River water. These tests employed dry salts (GP-2 composition) to manipulate the conductivity of both treatment plant recycled water and de-ionised water to conductivity levels similar to those previously tested using the water flea.

The response of the water flea during a 48-hour exposure was consistent with that of the original bioassay conducted using recycled water and Nepean River wat er. These bioassay results, along with an understanding of the capacity for removal of contaminants of the combined tertiary treatment, ultrafiltration and reverse osmosis processes, indicate that the low conductivity is the stressor affecting the exposed organisms rather than an unidentified substance. The conductivity threshold identified by these laboratory investigations was approximately 120 µSiem, which is comparable with the lower end of the conductivity range for lowland South Eastern Australian rivers (125 µSiem to 2,200 µSiem) specified in the ANZECC (2000) fresh and marine wat er quality guidelines. A diagrammatic summary of the bioassay results is presented in Figure 5.

Conductivity Dispersion Study to Confirm Larger Scale Environmental Response

Figure 6. Boundary Creek inflow into the Nepean River at approximately 45 ML/day. 170 FEBRUARY 2010 water

To assess the significance of the conductivity threshold identified using the laboratory bioassays it was essential that a hydrodynamic model was developed to understand the mixing and dilution potential in the receiving environment. In order to develop such a model a conductivity dispersion investigation was carried out at the confluence of Boundary Creek and the Nepean River.

technical features


river health The cond uctivity 1000 dispersion field investigation generated ,00 1 - - - -- -- - - - - - - -- - - -- - - - - - -- -- - - - - - - t sufficient data to estimate e plume dispersion patterns ! ~ t - ~N~e~a~n~Riv~ er~ d~ns~ ~ tre~am~o~ rd~,~~ar~e·~ ~ -- -- - - - - - -- - -- - - - - -- - ~ ~ ~ • Prior to treatment plant commissioning under the current STP ~ .·;., discharge regime, ~ 11 <00 enabling predications of 8 mixing patterns and 200 associated conductivities Minimum conductivity required to limit potenbal for adverse biological response under the proposed treatment plant discharge 11 21 31 51 61 71 Percentage of results regime. The assessment involved measurement of Figure 7. Distribution of Nepean River conductivity levels before and after commissioning of the treatment conductivity at multiple plant. locations on multiple recommends that conductivity in lowland What this Means in Terms of occasions over a four-hour period on a rivers in SE Australia should be between Environmental Hazard and Risk single day during dry weather flow 125 and 2,200 µSiem. Although some conditions. Dry weather flows are The recycled water from the treatment waterways in Australia e.g. tropical rivers, considered to be the worst-case scenario plant has the pot ential to induce alpine regions and lakes, may have as the discharge from the treatment plant osmoregu latory stress on freshwater conductivities as low as 20-30 µSi em will represent a relatively high proportion organisms due to low conductivity below (ANZECC 2000), these low conductivity of the total flow when Nepean River flows a certain threshold level. Bioassays water bodies do not support t he range of are low. Measurements were collected undertaken for the Replacement Flows aquatic life that is found in t he Nepean during Penrith STP peak daily dry Project identified this level to be around River system wh ich typically has weather discharge (approximately 45 120 µSiem. Th is is consistent with the conductivity levels around 200MUday; Figure 6) which is a similar flow ANZECC (2000) guideline that 300 µSiem. to the anticipated discharge flow regime (up to 50 MUday) for the treatment plant.

.,

Cormix modelling (Gl-4.3 soft ware) provided an estimation of the dilutions of Boundary Creek wat er once it enters the Nepean River under the post treatment plant commissioning discharge reg ime. From this, the likely conductivity of the Nepean River water at increasing distances downstream from Boundary Creek was hydrodynamically modelled. It was also important to understand the likelihood of cond uctivity falling below the approximate threshold level of 120 µSiem pending extreme flow conditions in the Nepean River. To determine t his, al l available flow and conductivity data for the Nepean River and Boundary Creek were used to predict conductivity levels in the Nepean River after comm issioning of the treatment plant. Conductivity levels in the Nepean River were predicted to be above 120 µSi em for all but approximately 15% of the time once the two water bodies were fu lly mixed (Figure 7). This is likely to occur either during extremely low flow conditions where the treatment plant discharge contributes a relatively higher proportion of river flows, or during periods of flooding where low conductivity catchment runoff has reduced conductivity levels throughout the river.

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water FEBRUARY 2010 171


river health

N

+

As such, it is unlikely that any adverse effects on aquatic organisms in the Nepean River wi ll be observed as a direct consequence of the low conductivity recycled water produced for the Replacement Flows Project. Sydney Water will continue to monitor the aquatic environment in the Nepean River and Boundary Creek following commissioning of the Project as part of statutory obligations and environmental responsibility.

Conclusion A weight-of-evidence environmental monitoring program was developed in consultation with relevant government stakeholders to verify the contributions to river health that were predicted to be achieved through the Replacement Flows Project. The monitoring period covers four to five years including pre and post commissioning investigations. The integrat ed monitoring program includes physical, chemical and biological components.

t

t

Eastern channel

Western channel

\

t

Shallow - -

t

Initial mixing zone I ' (pool)

Riffle-- . ~

PENRITH STP

,..._

t t

,... Fish Penrith Weir~ ladder

Figure 8. Mixing zone for the recycled water with the Nepean River (not to scale). The discharge of the highly treated recycled water at a cond uctivity of approximately 20-40 µmlcm presents a hazard and is ant icipated t o exert an adverse, but very localised effect on aquatic organisms in Boundary Creek during dry weather flow as it will comprise 100% of the flow. Boundary Creek is already a highly modified environment and has served as a transport channel for treated effluent from Penrith STP since its construction in 1940. Prior to the construction of Penrith STP, Boundary Creek was ephemeral, with typically no dry weather flow and supported minimal aquatic life. The risk posed to the aquatic biota in the Nepean River is considered to be negligible as a consequence of the low conductivity discharge from the treatment plant beyond the initial mixing zone. The mixing zone is a small pool, (less than 10 metres in diameter with a sand and rock base), at the confluence of Boundary Creek and the Nepean River. Beyond the mixing zone, the Nepean River forms two channels either side of a series of small islands and shallow riffle zones for approximately 450 metres unti l both chan nels merge (Figure 8). The results of the conductivity dispersion study indicate that during dry weather flow, the water quality of the west ern channel will remain relatively unchanged receiving flow over Penrith Weir, while the eastern channel will consist of a mix of treatment plant and Nepean River water. The modelled conductivity of the eastern channel was greater than 150 µSiem after initial mixing, which is above the 120 µSiem identified via bioassays as a desired lower conductivity limit, and above 125 µSiem recommended in the ANZECC (2000) water quality guidelines for lowland rivers in SE Australia.

172 FEBRUARY 2010 water

The question of whether or not the low mineral discharge will pose an environmental risk has been assessed through a suite of aquatic toxicity bioassays, a conductivity dispersion study and hydrodynamic modelling. A minimum conductivity value of around 120 µSiem was identified via bioassays to minimise the likelihood of osmoregulatory stress in exposed aquatic organisms. The results indicate that aquatic life in the Nepean River is unlikely to be adversely affected by the treatment plant discharge once initial mixing with the recycled water has taken place. The conductivity beyond the mixing zone is expected to be in excess of 120 µSiem, and be within the ANZECC range for lowland rivers of South Eastern Australia. In contrast, the Nepean River is expected to benefit from the reduced nutrients discharged into the Hawkesbury-Nepean River system.

Acknowledgments Ecotox Services Australia - Rick Krassoi and Amandine Vincent Sydney Water - Greg Allen, Stephen Blockwell, Natalie Marshall, Joe Pera, Pet er Tate and the Sydney Water Monitoring Services Group.

The Authors

Merran Griffith is a Project Manager in Science and Tech nology, Sydney Water, email Merran. Griffith@sydneywater.com. au. Steve Biddulph is the Team Leader Contracts Management Group, Sydney Water.

References ANZECC (2000) National Water Quality Management- Strategy - Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Environment and Conservation Council, Agriculture and Resource Management Council of Australia and New Zealand. Department of Planning (2007) Project Approval, Minister for Planning date 20 June 2007. NSW Government (2006) Metropolitan Water Plan 2006, NSW Government, Sydney. Sydney Water (2006) Western Sydney Recycled Water Initiative. Environmental Assessment for Replacement Flows Project. Prepared by Sydney Water and SKM. Sydney Water (2008) Replacement Flows Project: Aquatic Environmental Assessment Program 2008-2013.

technical features


~ ref e reed paper

water quality

MICROWAVE-POWERED UV DISINFECTION RECEIVES VALIDATION FOR 'CRYPTO' S Shmia, N Bradley Abstract A new technique for operating UV lamps has been commercialised and independently validated .

Introduction The presence of Cryptosporidium in both surface and groundwater potable water supplies is of particular concern because it spreads rapidly and is resistant to chlorine and other traditional chemical disinfectants. Ultraviolet (UV) disinfection has proven to be the most effective and economical means of treating water which contains Cryptosporidium oocysts. In the United States (US), the Environmental Prot ection Agency (USEPA) has developed regulations and guidelines for the application of UV to treat for Cryptosporidium. In the United Kingdom (UK), the Water Supply (Water Quality) Regulations 2000 (Amendment) Regulations 2007 were enacted in December 2007, calling for water suppliers to carry out Cryptosporidium risk assessments and to implement appropriate treatments. A recent development has been the use of mercury lamps which are excited by microwaves from an external magnetron unit, thus reducing maintenance and extending lamp life. This paper concludes with the results of a validation test of one such commercial unit for inactivation of a challenge organism, the MS2 bacteriophage.

UV Disinfection and the Regulatory Environment The highly effective germicidal effect of ultraviolet light has been known for more than 100 years. The first full-scale use of UV for disinfection was in 1910 at a water treatment system in Marseilles, France. The invention of neon tubes in the 1940s provided a more practical source of UV light - the low-pressure mercury vapour lamp. A significant number of installations utilising UV disinfection systems for the municipal wastewater market began taking place in the US during the early 1950s.

By the early 1980s, UV disinfection of wastewater had gained popularity due in part to the heightened regulatory requirements affecting the use of chlorine within the wastewater treatment process. The new regulations required dechlorination prior to discharge, the installation of chlorine scrubbers to protect against accidental release of chlorine gas (Uniform Fire Code) and the development of risk management plans in case of accidental release (Occupational Safety and Health Act). UV disinfection has gained recognition as a beneficial technique in disinfection systems for municipal drinking water. Its simplicity, easy installation and retrofit coupled with low operating and capital costs have made UV disinfection attractive. To ensure the highest measure of safety to a nation's water supply, regulations governing water disinfection are always being reviewed as improved disinfection methods for water treatment evolve. In 1969, the US Department of Health, Education and Welfare, Public Health Service, Division of Environmental Engineering and Food Protection issued a guideline that UV systems should provide a minimum dose of 16,000 ÂľWs/cm 2 when used to treat drinking water. In November 2006, the USEPA released the Long Term 2 Enhanced Surface Water Treatment Rule (LT2), Ultraviolet Disinfection Guidance Manual (USEPA, 2006). Known as the UVDGM, this regulation provides guidelines and requi rements for all public water systems in the US to monitor and, if required , install UV disinfection equipment to treat for Cryptosporidium and other bacteria. The UVDGM provides equipment manufacturers with bioassay-based

Successfully validated against MS2 bacteriophage.

validation criteria to assure that the equipment will furnish sufficient disinfection to handle Cryptosporidium and other waterborne pathogens. Once fully implemented, all equipment manufacturers supplying to public water systems in the United States must have their equipment validated by a third party in accordance with the UVDGM. Currently, the European Union (EU) does not have any specific standards pertaining to Cryptosporidium risk assessments or suggested appropriate treatment methods. The EU does have a general requirement that drinking water must not contain harmful concentrations of any potentially dangerous microorganism or parasite, including Cryptosporidium. However, as a result of past outbreaks, regulations in the UK are more stringent than those found governing the EU. In 1999, the UK government introduced regulations to address Cryptosporidium. The regu lations called for daily sampling and testing of water for the presence of Cryptosporidium oocyst s. If oocysts were found in sufficient quantities to be considered a health risk, the regulation req uired the removal of all oocysts greater than 1 micron in diameter through microfiltration. UV was not an approved treatment for Cryptosporidium in the UK at that time. Within the first year of monitoring sites, 332 out of the 1,481 treatment works in England and Wales were identified as being at significant risk. Of the 332 at significant risk, 158 were surface water and 174 were groundwater. On 22 December 2007, the Water Supply (Water Quality) Regulations 2000 (Amendment) Regulations 2007 introduced new legislation in the UK regarding Cryptosporidium (Water Supply, 2007) . The new regulations put the onus on water suppliers, making the detection of harmful levels of Cryptosporidium in their potable water supplies a criminal offence. The new regulations have revoked the sampling

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water quality regime and the requirement to treat with 1 micron filters. Water companies are now requi red to carry out a risk assessment by sampling their raw water sources for several parameters. Should harmful organisms be found , the water supplier is required to implement the necessary treatment steps, which can now include UV. The responsibility is on the water company to justify and validate the treatment steps and how they can be monitored to prove efficacy. UK Water Industry Research (UKWIR,2008) is currently working on a project to determine the efficacy of UV disinfection and make recommendations on the operational guidelines for UV disinfection in the UK. The UKWIR work has drawn heavily on experiences outside the UK where UV technology is a far more prevalent treatment method, particularly in the US where the USEPA has produced specifications and guidelines.

Benefits of UV Disinfection As already discussed, Cryptosporidium has been found to be resistant to traditional disinfectants such as chlorine. The proven treatments for Cryptosporidium are filtration (membrane or sand), ozonation and UV disinfection. Properly used, UV disinfection offers a number of advantages in municipal water treatment systems. These may be summarised as follows: 1 . UV has been proven at a specified wavelength (254 nm) to inactivate Giardia Lambia cysts and Cryptosporidium Parvum oocysts - harmful parasites that are difficult to render harmless by other disinfectants. And UV does this using a low, cost-effective dose. Recent findings, moreover, have confirmed similar effectiveness of UV for many other human pathogens, including resistant viruses. UV is capable of effectively treating certain bacteria found to be unaffected by chlorine disinfection. 2. The contact times for UV disinfection systems are generally quite short - a matter of seconds. As a result, UV units are compact and have a small footprint, allowing them to be easily added as part of an existing multiple-barrier system. A multiple-barrier system refers to a treatment process that consists of various stages of filtration and disinfection that water must travel through prior to reaching the point of distribution. 3. Moreover, UV does not pose any of the safety concerns for management and 174 FEBRUARY 2010

water

refereed pape r

Table 1. UV Dose Requirements (mJ/cm2) Target Pathogens

Log inactivation 0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Cryptosporidium

1.6

2.5

3.9

Giardia

1.5 39

2.1 58

3.0 79

5.8 5.2

8.5 7.7 121

12 11 143

15 15

22 22

163

186

Virus

handling when compared to traditional disinfectants such as chlorine, which can be extremely dangerous to workers who are exposed to accidental releases. 4. The potential is low for UV reactions themselves to produce undesirable organic disinfection by-products (DBPs) in the treated water. UV intensities involved are less than those that can cause photochemical effects. Further, since there are no halogens like ch lorine in this physical process, there are no direct by-products to worry about, such as trihaloamines (THMs) or haloacetic acids (HAAs). Similarly, UV cannot form undesirable bromates. 5. However, UV treatment itself leaves no residual and may need an additional terminal disinfectant, such as chlorine, to achieve a residual. The formation of DBPs is still possible with the use of chlorine as a terminal disinfectant, depending upon the level of residual concentrations of organic and other compounds in the water. However, the potential formation of such DBPs could be reduced due to the use of lower levels of chlorine required , which also reduces costs. UV works by altering the DNA of microbes as they pass the light source in a reactor. Microbes with altered DNA are unable to reproduce, effectively making them harmless. When selecting a UV reactor for potable water, the reactor must be sized to provide a UV dose capable of inactivating the target pathogens. Significant research has been done to determine the log inactivation (i.e. the per cent removal) of various pathogens (Table 1). A 4-log reduction equates to 99.99% removal of pathogens. The UV dose delivered is inversely proportional to the flow rate and the UV transmittance of the water. Transmittance measures the amount of UV light which can pass through the water and is measured as a per cent of UV. Filtered drinking water plants typically yield water with 95 per cent ultraviolet transm ittance (UVT) or better; unfiltered plants range from 85 per cent UVT or better.

100

The USEPA calls for a multiple-barrier approach to treating for Cryptosporidium. Therefore, water plant s employ several technologies in conjunction. Each technology adds a "Crypto Credit" or one log reduction value to the entire treatment works. Typical plant s require anywhere from four to six crypto credits to produce crypto-free d rinking water. Combining UV disinfection with sand filters or deep bed filtration as a form of pre-treatment is often t he most economic means for removing Cryptosporidium. Ozone, the cost of which has come down significantly in the last 15 years, is a powerful oxidiser whic h will inactivate Cryptosporidium, but it also breaks down the naturally occurring organic matter present in water, causing it to become a nutrient source for bacteria. Therefore, the use of ozone can stimulate the growth of harmful bacteria in the distribution system. Ozone also has the potential to introduce bromate ions into the water in sufficient quantities to exceed the regulatory limits for bromate.

Operation of Ultraviolet Equipment During operation, UV equipment must be carefully operated and monitored in order to achieve proper disinfection. Regulations in the US call for UV disinfection equipment to demonstrate that at least 95 per cent of the water delivered to the public each month is treated by UV reactors operating withi n their validated limits. Such limits include UVT, flow rate and dose or intensity. Therefore, in order to meet t he requirements, operating tasks include assuring that lamps are lit, verifying lamp intensity or dose, and recording pertinent data on the plant logs. Today's UV systems offer control packages wh ich integrate with plant SCADA systems t o alert operators to the performance of the UV system and the disinfection it is providing. Routine maintenance tasks include cleaning the UV reactors, verifyi ng sensors and replacing lamps and sleeves, which assure the reactors deliver the required dose.

technical features


[il

water qua I ity

refereed paper

Operating costs for a typical drinking water UV system include power consumption, parts and maintenance. Traditionally, UV reactors use either low pressure high output (LPHO) lamps, or medium pressure (MP) lamps. LPHO lamps draw 100 to 300 watts per lamp, operating at a supplied power efficiency of around 30 per cent. Medium pressure lamps draw anywhere from 1,000 to 3,000 watts per lamp and operate at a wall power efficiency of around 15 per cent. Both types of lamps fade as their electrodes wear out over time, which leads to systems that are oversized when first installed. Therefore, power consumption is a primary concern , especially for larger drinking water facilities, which utilise hundreds of lamps to maintain proper disinfection. Maintenance costs are an additional concern for drinking water plant operators. LPHO lamps typically last 9,000 to 12,000 hours (about one year) with a prorated warranty shou ld they fail prior to meeting their projected life. Therefore, should a lamp fail within the first six months, the user will only receive 50 per cent credit for the failed lamp from the UV equipment manufacturer. Each LPHO lamp can cost up to USD$300 each. Medium pressure lamps are warranted for even less time, usually only 4,000 hours, and can cost more than USD$1 ,600 per lamp. In addition to replacement costs for lamps and related items, plant operators also must account for the time it takes to replace defective lamps as well as any equipment down time.

Microwave UV Disinfection A recent development in UV disinfection involves the use of microwaves to generate monochromatic UV light at 254 nm in low-pressure, high-output lamps - an extremely promising technology for use in water disinfection.

r I â&#x20AC;˘

Figure 1. Comparison of a conventional electrode lamp with filament electrode, with a microwave activated lamp. Microwave-activated UV lamps have been in operation for more than twenty years, but on ly for industrial applications such as UV-curing of inks and adhesives. They had the advantage of virtually instantaneous start-up and ability to be switched on and off frequently without deterioration. Their application to water disinfection was first commercialised by Quay Technologies, UK in 1998 and the systems are patented by J. Meier and D. Collins (Gutierrez et al, 2006). Figure 1 compares a conventional electrode lamp with filament electrode, with a microwave activated lamp. Figure 2 is a schematic of the system. Figure 3 is an image of a single lamp assembly. Because the system is powered by microwaves, such lamps last significantly longer than traditional systems. There are no electrodes used in the lamps, the cause of gradual deterioration in conventional lamps, so that a manufacturer can offer a three-year

FLOW OUTLET

FLOW INLET

COOLING FAN BOX

MICROWAVE GENERATOR

AIR FLOW

QUARTZ SLEEVE

Figure 2. Schematic diagram of the system.

WAVEGUIDE

ELECTRODELESS BULB

warranty on lamp life, compared to the one year typical on traditional syst ems. The power is applied by ext ernal magnetron units, similar to those used in domestic microwave ovens. These magnetrons have an operating life of over 10,000 hours in continuous service, are mass-produced, inexpensive and easily replaced. Such lamps have unlimited on/off capabi lity. The electrical efficiency of the microwave powered lamps is comparable to the efficiency of typical LPHO lamps. In addition, t he quartz sleeve remains the same temperature of the water, thereby reducing foul ing. With the acquisition in 2007 of Quay Technologies, the global company, Severn Trent Services, is now undertaking commercial application under the trade mark, MicroDynamicsÂŽ. The MD 2-Lamp chamber is 20 inches in diameter, and is specified with 150 mm PN1 6 (eq uivalent 6-inch) flanged inlet and outlet ports installed perpendicularly on either end of the chamber body. Water enters and exits through these ports, and flows parallel to 2 lamps, which are mounted along the longitudinal axis of the chamber, individually sheathed in quartz sleeves. The "lamp" referred to for the MD reactor actually comprises four low-pressure mercury lamps, without the tungsten elements found in conventional UV lamps. These are "bundled" and sheathed in a large-diameter quartz sleeve, each open on both ends, and inserted through the reactor and supported by compression rings at both ends of the reactor shell. The lamps are powered by a microwave generator and fitted with a wave guide. The unit is

water FEBRUARY 2010 175


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~ refereed paper

to 3-log reduction of Cryptosporidium. The additional log reduction credits are achieved via other technologies such as filtration or additional forms of disinfection. When additional treatment systems wi ll not be used in conjunction with UV, a UV system can be sized for a 4-log reduction.

Conclusion

Figure 3. Image of the lamp assembly. equipped with an automatic wiper for cleaning the quartz surfaces. A single UVC intensity monitor is installed on the unit, mounted through the chamber wall, at approximately the centre point of one of the two lamps. It provides a frequency output that is proportional to the incident intensity. The design ensures simplified and safer maintenance compared to other systems. Extensive testi ng has been done to confi rm and ensure that the microwaves are completely contained within the wave guide.

MicroDynamics Validation to UVDGM The system is ideal to treat Cryptosporidium and in 2008 was validated for a 4-log Cryptosporidium credit by HydroQual Environmental Engineers and Scientists, P.C. as per the lat est USEPA UV Disinfection Guidance Manual LT2 regu lations, using the MS2 bacteriophage as the chal lenge organism. A MicroDynamics CV02 unit's performance was validated at 90 per cent input power for an operating range between 78.2 per cent and 95.8 per cent UVT and flows between 129 and 1,416 GPM . Testing was completed in June 2008, inclusive of technical evaluations of system components and biodosimetric tests to assess dose-delivery performance using Intensity Setpoint Cont rol and Calculated Dose approaches. The primary objective of this validation test was to demonstrate and validate the dose-delivery performance of the MicroDynamics MD 2-Lamp UV system. Within this framework, specific objectives included: 1. Establish the minimum intensity setpoint of the unit, at which the credited Reduction Equivalent Dose (RED) is sufficient to achieve 4-log Cryptosporidium inactivation. This setpoint is determined at critical conditions of power and UVT. 2. Validate the MS2 RED by biodosimetry. 3. Develop and/or confirm a dose-control algorithm that is capable of maintaining RED levels at or above those required for disinfection compliance across the expected operating range of the UV reactor. 4. Establish the validated RED performance of the reactor, based on the observed interpolation uncertainties of the dosecontrol algorithm, the bias adjustments related to the challenge organism and quality assurance parameters defined in the UVDGM. 5. Determine the headloss through the unit at its rated maximum flow. 6. Assess UV sensor cal ibration against equivalent reference sensors. 7. Determine power consumption. UV is often used in conjunction with other treatment technologies to obtain a 6-log reduction for an entire treatment plant. Typically a UV system is sized to provide between and 2-

176 FEBRUARY 2010 water

The use of ultraviolet light to disinfect drinking water is growing among public water systems. In the US, potable wat er disinfection using UV is a fai rly recent approach, with the first large-scale system (2 MGD) debuting in 1987. Better established as wastewater treatment, UV has been slow to find application in drinking water plants. Experience derived from some recent large installations should help popularise the method. In 2000 more than 400 UV disinfection facilities worldwide were treating drinking water with UV. In 2006, less then 1 per cent of US drinking water systems were using UV disinfection. However, the number of public water systems using UV disinfection on a global scale is expected to increase significantly over the next decade. A single MicroDynamics CV02 system can treat flow rates up to 1,200 GPM (6,000 m3/ day), depending on the required disinfection duty, i.e. UV dose requ irement, target organism and water UVT. Multiple vessels can be arranged in series or parallel to increase the flow rate through the system. It is available in two-lamp vessels (CV02) and four-lamp channel systems (OCS 660). In addition, the closed vessel systems are suitable for high-pressure design operations up to 10 bar (145 psi).

The Authors Stanley Shmia is UV Disinfection Product Manager, Severn Trent Services and Nigel Bradley is Engineering Manager, Severn Trent Services. Shmia is based out of the Colmar, PA USA facility. Email sshmia@severntrentservices.com and Bradley is based out of the Tamworth, UK facility, nbrad ley@severntrentservices.co. u k.

References Gutierrez R L. , Bourgeous KN., Salveson A, Meir J, Slater A (2006) Microwave UV: a new wave of tertiary disinfection WEFTEC USEPA, Long Term 2 Enhanced Surface Water Treatment Rule (LT2}, Ultraviolet Disinfection Guidance Manual Final, EPA 815-R-06-007, November 2006 UKWIR 2008, UV Inactivation for Crypto, - a review and cost comparison, http://www. u kwir. org/ content/defau It .asp? Pageld=382 4 7&expanded= 1&Catld=3 Water Supply (Water Quality} Regulations 2000 (Amendment} Regulations 2007, http://www.opsi.gov.uk/si/si2007/uksi_20072734_en_ 1.htm

Further Reading BBC News, http://news.bbc.co.uk/2/hi/uk_news/scotland/2171593.stm Centers for Disease Control - Cryptosporidium Fact Sheet , http://www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/factsht_ cryptosporidiosis.htm#2 Developments in Ozone Technology, http://wwdmag.com/Developments-inOzone-Technology-article31 71 Drinking Water 2000, A Report by the Chief Inspector, Drinking Water Inspectorate, http://www.dwi.gov.uk/pubs/annweb00/42.htm Martin Kane, E-Mail, Director of Customer Relations, Severn Trent Water Ltd, sent Wednesday, December 19, 2007 Paul Overbeck, Ozone Process Optimization, Water & Wastewater Digest, December 2007 Water UK Policy Paper, http://www.water.org.uk/home/policy/positions/cryptosporidium UV and Cryptosporidium Report by Mike Carney, 21 December 2007

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