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AWA

ABN 78 096 035 773


~ AWA CONTACT DETAILS ~ 'Promoting the sustainable ...::::,:.. management ofwater' POSTAL ADDRESS PO Box 3B8, ARTARMON NSW 1570

Journal of the Australian Water Association

EMAIL info@awa.asn.au WEBSITE http://www.awa .asn.au PRESIDENT

ISSN 03 10-0367

Darryl Day · president@awa.asn .au

CHIEF EXECUTIVE OFFICER Chris Davis · cdavis@awa.asn.au

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

EVENTS Linda Phi llips· 61 2 9495 9914 lphillips@awa.asn.au

MEMBERSHIP INFORMATION AND INQUIRIES Michael Seller · 02 6581 3483 mseller@awo.asn.au

MEMBERSHIP RENEWALS AND CHANGES Membersh ip Team· 1300 361 426 info@awa.asn.au

MEDIA AND MARKETING Jennifer Sage · jsage@awa.asn.au

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

WATER EDUCATION NETWORK Corinne Cheeseman · 6 1 2 9495 9907 ccheesma n@awa.asn.au

NATIONAL SPECIALIST NETWORK Laura Evanson· 61 2 9495 9917 levanson@awa.asn. au

AWA BRANCHES: AUSTRALIAN CAPITAL TERRITORY and NEW SOUTH WALES Errin Dryden· 61 2 9495 9908 edryden@awa.asn.au NORTHERN TERRITORY c/o Ian Jarman· 61 2 9495 991 1 ijarman@awa.asn.au SOUTH AUSTRALIA Sarah Carey · 61 8 8267 1783 sabranch@awa.asn.au QUEENSLAND Kathy Bou rbon· 6 1 7 3397 5644 awaq@awa.asn.au TASMANIA & VICTORIA BRANCH c/o Rachel-ann Martin · 61 3 9235 1416 tasbranch@awa.asn.au vicbranch@awa.asn.au WESTERN AUSTRALIA Cath Miller· 04 16 289 075 cmi ller@awa .asn.au INTERNATIONAL WATER ASSOCIATION, AUST. (IWAA) c/o Ch ris Davis· cdavis@awa. asn.au

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

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

Volume 34 No l Februa ry 2007

AWA WATER JOURNAL MISSION STATEMENT 'To provide a print iournal that interests andinforms on water matters, Australian and international, covering technological, environmental, economic and social aspects, and to provide a repository of useful refereedpapers.' PUBLISH DATES Water Journal is published eight times per year: February, March, May, June, August, September, November and December EDITORIAL BOARD: Chairman: FR Bishop BN Anderson, TAnderson, CDiaper, GFinlayson, AGibson, GA Holder, BLabza, MMuntisov, CPorter, DPower, FRoddick EDITORIAL SUBMISSIONS Water Journal invites editorial submissions for: Technical Papers and topical articles, Opinion, News, New Products and Business Information. Acceptance of editorial submissions is subject to editorial board discretion. Email your submissions to one of the following three categories: 1. TECHNICAL PAPERS AND FEATURES Bob Swinton, Technical Editor, Water Journal: bswinton@bigpond.net.au AND journal@awa.asn.au Papers of 3000-4000 words (allowing for graphics); or topical stories of up to 2,000 words. relating to all areas of the water cycle and water business. Submissions are tabled at monthly editorial board meetings and where appropriate are assigned to referees. Referee comments will be forwarded to the principal author for further action. See box on page 14 for more details. 2. OPINION, INDUSTRY NEWS, PROFESSIONAL DEVELOPMENT Jennifer Sage, jsage@awa.asn.au Articles of 1000 words or less 3. WATER BUSINESS Brian Rault, National Sales & Advertising Manager, Hallmark Editions brian.rault@halledit.com.au Water Business updates readers on new products and associated business news within the water sector. ADVERTISING Brian Rault, National Sales & Advertising Manager, Hallmark Editions Tel: 61 3 8534 5014 (direct), 61 3 8534 5000 (switch), brian.rault@halledit.com.au Advertisements are included as an information service to readers and are reviewed before publication to ensure relevance to the water environment and objectives of AWA. PURCHASING WATER JOURNAL Single issues available @ $12.50 plus postage and handling; email dwiesner@awa.asn.au BACK ISSUES Water Journal back issues are available to AWA members at www.awa.asn.au PUBLISHER Hallmark Editions, PO BOX84, HAMPTON, VICTORIA 3188 Tel: 61 3 8534 5000 Fax: 61 3 9530 8911 Email: hallmark.editions@halledit.com.au Journal of the Australian Water Association

Water

FEBRUARY 2007


Journal of the Australian Water Association

Walking the Waikanae River, Kapiti Coast District - see page 84

3D rendering of a Digital Elevation Model - see page 93

Shanghai Metro Collapse - 2003 - see page 104

OPINION AND INDUSTRY NEWS OPINION DDoy, President, AWA Delivering Our Water Future CDavis, CEO, AWA What's a Healthy Association? Prof Warwick Anderson AM, Chief Executive Officer, NHMRC My Point of View AWA NEWS Includes: Water Education Network (WEN), Young Water Professionals, WaterAid Australia, Smart Approved WaterMark, National Water Commission, AWA National Awards

4

5

6 8

CROSSCURRENT National Issues and Policy, International, States, Clippings, People in the News

32

AWA MEMBERSHIP NEWS New Members

58

PROFESSIONAL DEVELOPMENT 60 62

NATIONAL EVENT CALENDAR Events, Call for Papers, Conference Report

TECHNICAL FEATURES (U indicates the paper has been refereed] CATCHMENT MANAGEMENT Assessing the Future Risks to Irrigation in the MDB Forecasting and planning for on uncertain future

[ii Success Factors for Community-Based River Management in New Zealand Putting concepts such as ICM into practice has often proven difficult ~ Decision Tools for Catchment Planning Decision tools deal with uncertainty and complexity [i] Limitations of Library-Dependent Microbial Source Tracking Methods Problems in identifying the sources of contamination in polluted waters

TRENCHLESS TECHNOLOGY No Dig Down Under 24th International Conference, Brisbone 2006 Contract Insurance: Lessons from the World's Tunnelling Insurers The International Tunnel Insurers Group Code: Proper risk assessment is essential Major Pipe Jacking for Perth Desalination and Main Sewer Projects Mitigating pro;ect risks for microtunnelling in a congested urban environment 2 FEBRUARY 2007

Water

Journal of the Australian Water Association

WCraik

78

NBEdgar

84

DWatson

93

WAhmed

96

Report by EA (Bob) Swinton

102

ADix

104

MI Oliver, DBoland, MJ MocCormick, J CBower

108


Volume 34 No 1 February 2007

GAB Mound Spring in Far North South Australia - see page l 24

Iron-rich and acidic drainage from underground mine - see page 132

The Queensland Nickel Refinery at Yabulu - see pa ge 139

Improved Detectability of Underground Infrastructure - the Stakeholders' Perspective Finding the accuracy targets for a moior UK development of multi-sensory techniques CDFRogers, AMThomas, NMetje, DNChapman Trials of the Corrosion Inhibitor, Sulfalock HiGel™ S Barclay, SJessop, S Le(ount, DMcMinn, KJohns Magnesium hydroxide protects a sewer crown

WATER IN MINING Water for Mining - Issues of Supply The water industry needs to prepare itself for the inevitable policy debates Water: Issues of Quantity and Quality Operational issues may be relatively easy to manage, but post-closure issues must dominate planning Acid and Metalliferous Drainage (AMD} It is crucial to assess AMD risks as early as possible Membrane-Based Solutions for Mineral Processes Extending membrane technology to exotic solutions. The Queensland Nickel Water Recycling Facility: Six Years of Operation Recycling water in a mineral processing plant has problems, but they con be overcome

114 1 20

BKracman

1 24

J Taylor, S Pape

129

J Taylor, S Pape

132

PMacintosh

136

NPalmer, J Taylor

139

WATER SUPPLY Ii] International Collaborative Research on Discoloured Water Identifying the causes of distribution system discolouration events J Q J CVerberk, CDoolan, AJayaratne, PRTeasdale, J HGVreeburg, KO'Halloran, L. Hamilton, DVitanage 144 SUSTAINABILITY ~ Water Governance Regimes in Australia: Implementing the National Water Initiative The opinions of 183 CEOs on implementing ESD

J MMcKay

150

WATER BUSINESS NEW PRODUCTS AND BUSINESS INFORMATION · SPECIAL FEATURES: WASTEWATER & REUSE AND PIPES ADVERTISERS' INDEX

157 176

OUR COVER Both mining and mineral processing have to deal with the problems ofwater supply and discharge to the environment in both arid and monsoonal climates. Recycling water can be a valuable solution, but it is never simple. Our feature, Water in Mining, gives a few examples. Our cover shows recycled water entering the reservoir at Queensland Nickel's facility near Townsville (page 139). Photo courtesy of United Utilities Australia.

Journal of the Australian Water Association

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FEBRUARY 2007 3


DELIVERING OUR WATER FUTURE It's not surprising that, after many drought years, and wide acceptance that climate change is real and with us, there is a h igh degree of nervousness, and indeed angst, around Australia about our water futu re. The viability of ru ral commun ities is on the line, alo ng with the lifesryle and amenity of those living in o ur cities. Younger generations have grown u p without experiencing water restrictions, let alone the threat of serious water shortages impacting our environment and the economic future of Australia. The Australian Government's $10 billion National Pian for Water Security, an no unced on 25 January 20 07, supporting the 2004 National Water Initiative (Australia's blueprint for water reform) is loudly applauded. T he $1 0 billion plan is visio nary and ambitious, and addresses many of the compromised positions and omissio ns from the 2004 blueprint for water reform. Similarly, the newly created portfolio of Environment and Water Reso urces in Canberra and appointment of the highly regarded Malcolm Turn b ull to the Cabinet post provides the opportunity to align and focus the previously disparate activities of the Australian Government on the water agenda. The greatest risk to Prime Minister Howard's vision for water reform is actually delivering $10 billion over the next decade. The wheels of government bu reaucracy (at Commonwealth, state and territory level) turn notoriously slowly. The $ 10 billon plan needs to now be populated with milestones and timeframes and the Australian Government must consider who is b est placed ro deliver the outcomes. Australia can ill afford a highly politicised process, delaying the invest ment in our water furure. There are, however, several major omissions fro m the 2007 National Pian for Water Security and the 2004 National Water

Initiative. C limate change is impacting ou r water future and the new portfolio of Environment and Water Reso urces must address both mitigation and adaptation strategies. T he Australian Water Association has previously called for a national, strategic ap proach to climate change mitigation, including th e development of a low carbon economy. Regardless of the scope and scale o f actions taken to mitigate climate change locally, nationally and globally over the next ten years, the water sector must im plement a range of adap tive strategies to cope with o ur

4

FEBRUARY 2007

Water

research in to climate, water resources accounti ng and irrigation effi ciency. However, the plan, along with the 2004 National Water Initiative, has fa iled to recognise the investment required in water q uality and public health research, transfer of knowledge into practice and capaciry building. Innovation in where we source our water supply for urban use will o nly be supported by the community within a robust fra mework of health and environ ment regulation, based on sound science.

Darryl Day, AWA President changing future. Investment in research, transfer of knowledge into practice and capacity building are required ro adapt the way we manage o ur ground and surface water resources and how we use our ocher resources. Every regional catchment, city and community requires adaptive management ro be included as part of the water plannin g process. The Australian Water Association welcomes the reform of the Murray-Darling Basin Com mission ro improve the health of the rivers and wed ands and achieve sustainable benefits ro all com munities dependent on the lifeblood provided by the ground and surface waters in the basin. T he reforms will be politically and socially challenging and must add ress land use as part of the focus on catchment management in addition to accounting for water avai lability and water use. However, there appears limited incentive, and indeed appetite, fo r furth er institutional reform of catchment managemen t, bulk water providers and urban water business to provide good governance and the necessary capacity and capabilities. Water b usiness requires the commercial disciplines of asset and risk management to provide a sustainable futu re for our communities and water dependent enterprises. U nderinvestment in our catchments and assets and under-pricing of water resources are neither sustainab le, nor a proud legacy ro leave for the next generation. All water business must operate within contemporary corporate models with clear com mercial, social and environmental objectives . The use of water revenue as a cash stream to fund co mmunity services, with a resultant under-investment in water businesses is not yet on the political agenda. Reform of unsustainable water business is both necessary an d inevitable. The $10 billion National Plan for Water Security wi ll provide so me support for

Journal of the Australian Water Association

Austral ia has led the world in adapting a risk based, multi-barrier, catch men t to customer approach to provid ing safe d ri nking water. The trust of our communi ties in dri nking water must not be compromised and the protection of public health must remain the paramount consideration. Australia must not b e a nation that turns to bottled water though the loss of trust in drinking water from the rap. The agenda for indirect potable reuse to supplement drinking water supplies has moved ahead of the development of sou nd health guidelines, regulatory capability and exp ertise of our water businesses. Increased investment in research, transfer of knowledge into practice and capacity building are required in areas from the understanding and management of wastewater catchments through to governance structures for service delivery and regulation. Similarly, investment in water quality and treatment research is required to support other innovatio ns as we seek to diversify our water source options and develop more sustainable commun ities . Australia has a un ique opportunity over the next decade to develop a sustainable water future. Leadersh ip will determin e if this opportun iry is seized or lost. I look forward to meet ing many of you in Syd ney next month at Ozwarer 2007.

Darryl Day

water

FUTURE FEATURES MARCH ¡ Workforce i ssues & traini ng , sludge drying, odour

MAY ¡ Membranes , desa li na tion , indirect recycling

JUNE ¡ Water trad ing, groundwater use, de mand management


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technical features I

ASSESSING THE FUTURE RISKS TO IRRIGATION IN THE MDB Wendy Craik, Chief Executive, Murray Darling Basin Commission SIX GOVERNMENTS C'wealth NSW Vic SA Qld ACT I

-

Community Advisory Committee

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MURRAY-DARLING BASIN MINISTERIAL COUNCIL Up to 3 Ministers from each Government land, water and envl

I MURRAY-DARLING BASIN COMMISSION 1 Independent President 2 Commissioners from each Government

I Commission Office Technical and admlnistratlve secretariat

Figure 2. Distribution of Australia's surface run-off.

Figure 1. Structure of the Commission.

This is an edited version ofDr Craik 's address to the ANCID conference, October 2006.

If there is any positive aspect of our current prolonged drought it would be that for perhaps the first time the plight of the farmers has caught the attention of the cities. As an aside, I feel that many in this current audience are asking why our Commission is so slow in making decisions. My answer is to refer to Figure 1. We live and work at the very bottom of this edifi ce, and every one in the hierarchy above us has very definite views, by no means in harmony. We have to face facts. Unfortunately they are somewhat grim. T he Murray Darling has only 6% of Australia's run-off, (Figure 2) and our stored groundwater is already well-used and yet we produce some 40% of Australia's agricultural value, and 70% of our irrigated agricultural value. But how sustainable are we in the face of the estimates for climate change? Let's look at 11 5 years of histo ry. Figure 3 shows the total inflows to the river system. Note the long- term average is 11,200 GL/yr. Ou r current drought is just over half that, 6500 GL/yr, yet the 'Federation Drought' of 1902 was even

Forecasting and planning for an uncertain future. 78

FEBRUARY 2007

Water

However, th ere is one huge difference between 'Federation' and now, and that is the volume of abstractions. Figure 4 looks at the actual river flows at Euston, near

less than that, 5,700 GL/yr. Then have a look at the flood s. The question is, is today just a part of the variability or has climate change already hit us?

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Journal of the Australian Water Association

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Figure 5. Global temperature increase since 1860. the border of NSW, Victoria and South Australia. The long-term average is 8600 GL/yr but during 'Federation' it was still 6200 GL/yr, whereas in the last TEN years the average was only 2900 GL/yr to supply South Australia's Riverland, Adelaide and the Murray mouth. Our correlations from other periods of low Aow predicted that inAows from the remainder of 2006 would be very low indeed (and they were) . The result? Severe reductions in allocations to irrigators and water restrictions for communities. One of our major programs is the Commission's 'Risk Program' and it has one over-riding objective: To protect the integrity of the water access entitlements system and the achievement of environmental objectives as they relate to the shared water resources of the Murray-Darling Basin.

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Figure 6. Climate c ha nge and variability. Difference last five yea rs vs 20 forego ing years. T o do that we have to forecast and plan for the fu ture. Our program framework is clear-cut: • Assess the various risks. • Model the inter-relationship and cumulative impacts of these risks. • Formulate policy responses: e.g. assigning risks to water-sharing, reducing impacrs. • Continue monitoring, evaluation and reporting. W hat are the risks?

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• Increased groundwater use • Bushfires in the catchments reducing run-off • Farm dams intercepting run-off • Reforestation reducing run-off • Reduced return Aows from better irrigation and water transport • Floodplain harvesting Dryland farming changes

Possible Impacts of Climate Change

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80

FEBRUARY 2007

Water

Journal of the Australian Water Association

There is no doubt that we are warming up (never mind why). Figure 5 dramatically ill ustrates this, when the differences from the average are plotted. Trying to pred ict the effect on rainfall and run-off is more di fficult, but Figure 6 shows that there are shifts already apparen t. There are apparent increases in the southwest, but decreases in the catchments for the reservo irs in the southeastern uplands, a cause for concern. We must therefore factor in decreased average rainfall, higher temperatures, increased frequency and severity of extreme events (Aoods as well as drought) but average stream Aows will decrease, and water quality also may well decrease. The CSIRO (2006) estimates for changes to stream flow are 0 to -20% for 2030, and +5 to - 45% fo r 2070. These ranges are expectedly large, but if the worst case scenarios are assumed, then the average and median flows will be decreased. While still searching for more reliable forecasting methods, we must plan for fu ture supply constraints, and analyse the effects of the changed flows on state shares as well as river health and sa linity. This is being done under the umbrella of the South Eastern Australian Cli mate Ini tiative, a coll aborative venture,


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budgeted for $7M over three years, involving 40 projects across three research themes: characterisation of current climate; high resolution climate projections and impacts; and seasonal forecasting.

Increased Groundwater Use Although groundwater use in the Basin is only about 10% of the average inflow to the river system, it is increasing, as shown in Figure 7, mainly in NSW. There are, of course, linkages between surface flows and groundwater and the time frames are being investigated. Other Risks These have been rough ly quantified in terms of effect on total water resources, and the pie-chart in Figure 8 gives the best estimates. It was perhaps surprising that apart from the possible effects of climate change, the biggest impact was the increasing capture of run-off by anxious farme rs in their own dams. T he grand total of these impacts could range from 2,500 to 5,500 GL/yr, roughly 11-25% of our present surface water resources.

Figure 8. Our shared water resource at risk (estimates) .

Yet CSIRO's estimates also show that each of the sub-catchments of the Basin wi ll be affected differently. So our major challenges are to provide localised information to our irrigators, to plan flexible responses, to assess the impacts of each of the risks on the other risks (because they are inter-related) and to th ink in terms of medium to long-term time-frames, not just the next year.

The Author Wendy Craik is Chief Executive of the Murray Darling Basin Commission, email wen dy.craik@m dbc.gov.au

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Journal of the Australian Water Association


technical features

catchment management

fereed paper

SUCCESS FACTORS FOR COMMUNITY-BASED RIVER MANAGEMENT IN NEW ZEALAND NB Edgar Abstract This article examines current approaches co community-based river management in New Zealand. There is considerable private and public investmen t in community-based approaches co river catchment management nationally. A recently completed two-year projecr examined community-based integrated catch ment management initiatives in New Zealand. This project identified a nu mber of success factors and

innovations found in community-based river management. Success factors include strategic planning, communication cools, partnership development, localised restoration and enviro nmental education. Concerns are raised about the focus on evaluating p rocess and socio economic outcomes of these initiatives without adequately addressi ng whether such initiatives improve the biophysical outcomes upon which they were originally founded.

Introduction The management of freshwater ecosystems within catchments (or watersheds) requires consideration of land and water issu es ac the scale of entire river basins (Hilden 2000; Parkes & Panelli 20 01). Integrated cacchmenc managemen t (I CM) is an approach that recognises the catchment or river basin as the appropriate organising unit for research on ecosystem processes for the purpose of managing natural resources in a context char includes social, eco nomic and political consideratio ns (Bowden 1999). In Australia and New Zealand there has been considerable public and private investment in in tegrated approaches co natural resource management ac a catchment scale, involving partnerships between government, industry and the community (Bellamy 1999; Bellamy et al.

Putting concepts such as ICM into practice has often proven difficult. 84

FEBRUARY 2007

Water

Walking the Waikanae River, Kapiti Coast District. 2001 ; Edgar 20 06). Concerns regarding the sustainable management of New Zealand's freshwater resources are receiving increased attention (Parkyn et al. 2002; Parliamentary Commissioner for che Environment 2004). Consequently, there has been an increasing focus on che need for greater integration of research, policy and relevant local action co address water resource issues and related environment and health considerations (M inistry for the Environment 20 05). However, che translation of the concept of such approaches as ICM into practice has often p roven difficult, with on-ground implementation being largely experimental and often fall ing far shore of community expectations (Bellamy eta!. 2001). Pare of the problem lies in the complexity ofICM. ICM in a resource management context inheren tly assumes an integrated approach. This requires in tegration co occur within and across a variety of configurations: among science disciplines; across spacial scales and temporal scales; from science through policy, management and education; and among knowledge providers, users and purchasers (Bowden 1999) . In many respects, the more integrated the approach to catchment management

Journal of the Australian Water Association

becomes, the more complex become the interdependencies between ics many elements. Mitchell (1990) argues rhac ICM may be contemplated in at lease three bas ic ways. Firstly, it can imply th e systematic consideration of the various dimensions of water: surface and groundwater, quantity and quality. The important aspect is the acceptance that water comprises an ecological system which is made up of a n umber of interdependent components. Each component may influence ocher components and therefore needs co be managed in che context of its interrelationships. Secondly, ICM can imply char, wh ile water is an interconnected system, it is also a component chat interacts with ocher systems. This p erspective directs us co address che interactions between water, land and the environment, recognising chat changes in any one may have consequences for che ochers. T his view is broader than the first, and requires attentio n to, and expertise in, both terrestrial and aquatic issues. The third and broadest interpretation ofICM is co approach it from the perspective of the inter-relationships between water and social


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technical features

lessons that have been learn t from the implementation of a broad range of lo cal, community-based ICM projects across the country. T h is p aper describes the ou tcomes of case srudy analysis of some of the leading co mmu nity-based river management projects in New Zealand . Case study analysis utilised a range of research methods including: one-on-one semi-structured interviews with project participants; focus group meetings with p roject participants (including commu nity, local government and research provider participants); and feedback from participants at regional and national catchment management workshops (Edgar 2003) .

Community-Based River Catchment Management Native tree plantings in the Waikanae River catchment, Kapiti Coast District.

and economic developmen t. At this level, ICM clo sely refl ects approaches ro sustainable development, with its fo cus upon the relationsh ip between the environment, the economy and society (Parliamentary Commissioner for the Environment 2004) . There is an intuitive appeal to the notion of examini ng a broad array of variables, and their interrelationsh ips, in the context of water and land management. However, care m ust be taken regarding the scope of integrated catchment management (Mitchell 1990). At a strategic (conceptual) level it is appropriate and desirable to think comprehensively, wh ere o ne considers the b road est possible range of variables which may be signi ficant for co-ordinated management of water and associated land and b iodiversity resou rces. H owever, at an operatio nal level, maintaining a comprehensive perspective may create d ifficulties. Essentially, the complexity and d ifficulty of trying ro sustain a comp rehensive app roach ro ICM at the operatio nal level can become overwhelming.

The NZ Landcare Trust in conjunction with New Zealand's M inistry fo r rh e Environment has now co mpleted a two-year Sustainable M anagement Fu nd project entitled: 'Integrated catchment management: sharing best practise nationally'. The purpose of the project was to establish a network of ICM practitioners and participants involved at the community level, and to provide opportunities fo r th ese people to share experiences, cools and app roaches throughout New Zealand (Edgar 2006). A key aim of the project was to identify

Integrated Catchment Management in New Zealand In New Zealand there are a large n umber of commun ity-based groups u ndertaking ecological resroration projects (Edgar 2003; Nimmo 2004; Jay 2005). Many of these projects involve rhe rehabilitarion of freshwater ecosystems, particularly streams, rivers, lakes and wetlands. Improving habitat q uality, particu larly riparian zone integrity and water quality, is a major focus of rhese community investments (Phillips et al. 2004). 86 FEBRUARY 2007

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Commu n ity-based river management projects in New Zealand cover a range of geographic scales and resource management issues. T hey include small urban streams less than six kilometres in length, ro the nation's th ird longest river. T hey range in community engagement from a catchment of scarcely over two square kilometres ro one of 5,650 km 2. The environ mental issues chat each community-based grou p are facing reflect the impacts o f the predominant land uses within each river catch ment. However, im proving water quality is a common goal for b oth che smaller urban river and the larger more rurally focused catchment grou ps (Edgar 2003). The community-based river management projects analysed in chis paper all have a high national and regio nal profile in New Zealand. A numb er of the p rojects h ave b een awarded the Min ist ry fo r the Environ ment's Green Ribbo n Award . The G reen Ribbo n Awards recognise o utstanding con tributions to sustaining, protecting and enhanci ng New Zealand's environment. In the word s of the Ministry for the Environment (20 02) the awards "are a public acknowledgement of the initiative, dedication and sheer hard work individuals, communities and organisations have put inro caring fo r our pare of the world" . Many of these award-winning communirybased river management projects have a number of common success facrors. These are described in rhe next section.

Success Factors in Community-Based River Management The commun ity-based river management p roject success fac tors described in this paper reflect many of the success factors chat were identified from interviews with ICM professionals and practitioners. T able


Vi ~ Systems & Solutions

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catchment management Table 1. Success Factors in Community-Based River Management. Success Factor

Description and Examples

Strategic Planning

Communication Tools Partnersh ip Development

Localised Restoration Environmental Education

Clear articulation of a group vision, mission and goals. Often accompan ied by detailed planning for specific obiectives, tasks or milestones. In advanced cases, development of a community-driven catchment management plan or strategy The use of a range of communication tools to maximise environmental awareness ra ising and to profi le the group's achievements !for example; newsletters, brochures, videos, website, public seminars, catchment tours) Strong partnership development with local government resource ma nagement agencies and educational institutes. Important for profiling the group, gaining community credibility and accessing resources !particularly, fundin g and specialist skills) Active rehabilitation of riparian zones or in-stream habitat. Establishment of demonstration sites to showcase the outcomes of community-based restoration efforts Development of environmental education programmes that complement direct restoration efforts. An effective way for school children to 'educate' their parents about resource management issues

1. provides a broad outline of the essential features of each success factor. For many community-based environmental restoration initiatives co be successful, whether it be river/lake management, wetland restoration or estuary enhancement, then most, if not all che above success factors will be inherit co che initiative. To be successful che initiative is likely co have wide community support, resourcing and acceptance by industry and government, and co have achieved so me measure of localised ecological restoration. In che context of chis paper, the case study initiatives were also recognised through regional or national environmental awards. le is important co realise char these com munity-based river management projects are leading edge initiatives in New Zealand. In many ways, what separates chem out from ocher aquatic ecological restoration projects is the extension of success factors identified in Table l . into much more advanced innovations. These project initiatives have essentially evolved from successful projects (first generation projects) co becoming innovators (second generation projects). Table 2. describes some of the innovative approaches char are used by these project parricipants.

Evaluating the Outcomes of Community-Based River Management The challenge co create policy processes, institutional arrangements and natural resource management chat contribute cowards achieving sustainable development outcomes requires rigorous evaluation as part of the process (Bellamy et al. 200 1). However, evaluation of natural resource management policy has been neglected with a substantial gap emerging between theory 88 FEBRUARY 2007

Water

and practice (Wallace et al 1995; Curtis et al. 1998). The same lack of eval uation of outcomes within institutional natural resource management policy processes also applies co collaborative natural resources management initiatives focused on community participation (Conley and Moote 2003). As community-based approaches co natural resource management gain prominence, there are increasing calls

for evaluations of both specific initiatives and che broader movement (Kellert et al. 2000; Selin et al. 2000; Leach & Pelkey 200 1). The interest in evaluating collaborative natural resource management initiatives like che community-based river management case studies described in chis paper relates co: â&#x20AC;˘ determining when che idealised narrative used co justify collaborative natural resource management holds true; â&#x20AC;˘ addressing criticisms of these efforcs; â&#x20AC;˘ assessing and refining efforcs co institutionalise a movement chat has developed largely at the grass roots level (Conley & Moote 2003). O bviously, community participants in river management initiatives wane evaluations chat can help improve their efforts and meet their personal needs. There are wide range of evaluative criteria chat can be used co gauge the success of communi ty-based river management initiatives (Bellamy 1999; Conley & Moore 2003). These criteria generally fa ll into three main types (1) process outcomes (for example, broadly shared vis ion , participation by local government, and diverse and inclusive participation); (2)

Table 2. In novative Approaches to Community-Based River Management. Establishing portfolios !with associated sub-committees) to divide up group tasks . For example: media, marketing and advocacy; membership and events; biodiversity a nd landscape management; environmental education; and fu nding and sponsorship Providing integrated guidance on landscape design, riparian zone management, native plant revegetation !including eco-sourcing of seeds), invasive weed control and reducing storm water pollution Seeking corporate sponsorship for riparian zone invasive weed eradication and native plant reestablishment. Corporate sponsors effectively become 'stewards' for individual lengths of the river Partnering with, and providing support for, local government environmental education and water qua lity monitoring initiatives Siting an environmental education centre and plant propagation nursery in close proxim ity to the stream riparian zone rehabilitation works Providing environmental education experiences beyond the basic stream/riparian zone restoration initiative. For example; offering school and adult education courses on natural history, waste minimisation, and flora/fauna identification Establishing a 'sister river' relationship to assist in the promotion of eco-tourism both locally and internationally !for example, signing a sister river partnership) Conducting novel field-based tours of the catchment and river to enhance local government politician and community member appreciation of the restoration work conducted by the group (for example, river rafting trips and bus tours) Partnering with local government's asset management teams to ensure a holistic and integrated approach is taken to the rehabilitation of the entire river flood plain, riparian zone and in-stream habitat Linking with a community-based history group to enhance the incorporation of cultural and social values into the bio-physical river restoration initiative Developing a 'Living laboratory' - an on-site research centre in the catchment that can provide: a la boratory; facili ties for students and community visits; a library; plant nursery and interpretation facilities Delivery of an educational waterways programme fo r local schools. The programme is specifically based on the catchment/river system, and incorporates mountains-to-sea resources on relevant resource management issues

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ra - - --• •.• -

environmental outcomes (for example, improved riparian habitat, impcoved water quality, and biodiversity enhanced); and (3) socioeconomic outcomes (for example, relationships built or strengthened, increased trust, and participant knowledge gain). H owever, what is apparent from both these New Zealand community-based river management case studies, and from the wider range of community-based ICM initiatives examined in the NZ Landcare Trust's national ICM project, is the lack of any process co evaluate both the short and long term success of these investments in collaborative natural resource management (Edgar 2006). This is particularly so for environmental outcomes. In most situations there is a complete lack of baseline information on the biophysical resource before the commun ity-based initiative commenced. In other words, a lack of land, water and biological diversity data on which co examine potential improvements in water quali ty, riparian and in-stream habitat qua li ty and biodiversity enhancement. Consequentl y, many of the perceived improvements in environ mental quality from initiative

ICM regional workshop at Lake Horowhenua, Manawatu-Wanganui Region.

participants are purely subjective and anecdotal in namre. Most evaluative reviews or surveys of community in volvement in river management tend to focus on either process or socioeconomic outcomes (Parkes & Panell i 200 l; Bowden et al. 2004; Nimmo 2004). A recent review of the Taieri Trust initiative in the Taieri River catchment of New Zealand's Otago Region illustrates the problem. Tyson et al. (2 005)

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stated that is was 'unrealistic to expect projects like the Taieri Trust to have significant and direct impacts on specific biological indicators of environmental health in three years' (of operation). W hat was considered realistic were expectations of ' improvements in stakeholder awareness and knowledge an d for networks to be established that will eventually result in environment improvements'. As valid as these views may be they do not address the


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underlying reason for the formation of these com munity-based river management groups - attempti ng to improve water quality.

Conclusions Th ough tful evaluatio n of the effectiveness of different communitybased app roaches to river management is central to understanding what can and cannot be expected of such processes and how they can be integrated with existi ng institutio ns (Conley & Moote 2003). Evaluation is fun damental to identifying change (environmental, social and economic), supporting an adaptive approach that is fl exible en ough to meet the challenge of change, and enabling progressive learning at individual, community, institut ional and policy levels (Bellamy et al. 200 1; Philips et al. 2004). In the absence of structured and coordinated attempts to implement evaluative frameworks, including biophysical evaluative criteria, it b ecomes impossible to determine the beneficial ou tcomes of often substantial private/public investment in river management. As a consequence community-based collaborative approaches ro natural resource management may be d iscarded before a fair and comprehensive assessmen t of their potential tole and impact is determ ined (Bellamy et al. 2001; Conley & Moote 2003). Ir is now imperative that efforts be made co support communities in developing robust framewo rks for evaluating the outco mes of their su bstantial vo luntary contributio ns to en hancing New Zealand's river environment.

The Author Dr Nicholas Boyd Edgar is Research M anager, New Zealand Land care Trust, University of Waikato, Hamilton , New Zealand. Email: nick.edgar@landcare.org.nz

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References Bellamy, J. A. ( 1999). Evaluation ofIntegrated Catchment Management in a Wet Tropical Environment, Collected papers of Land and Water Resources Research and Development Corporation. Research and Development Project CTC7. Volume 1: Synthesis of Findings, CSIRO Tropical Agricult ure, Brisbane. Bellamy, J . A., Walker, D . H ., McDonald, G . T. & Syme, G. J. (2001). A systems approach to the evaluation of natural resource management initiatives. journal ofEnvironmental Management 63, 407-423. Bowden, B. (1999). Integrated catchment management rediscovered: An essential tool for a new mi llen nium. In: Proceedings ofManaaki

Whenua Conference: A Three Day Conference on Science far Resource Management, 21-23 April 1999, Manaaki Whenua: Landcare, Te Papa, The Museum of New Zealand, Wellington. Bowden, W. B., Fenemor, A. & Deans, N. (2004). Integrated water and catchment research for the public good: the Motueka River-Tasman Bay initiative, New Zealand. Water Resources Development 20 (3), 31 1323. Conley, A. & Moote, M.A. (2003). Evaluating collaborat ive natural resource management. Society and Natural Resources 16, 371-386. Curtis, A., Robenson, A. & Race, D . (1998). Lessons from recent evaluations of natural resource management programs in Australia. Australian Journal ofEnvironmental Management 5(2), 109-119. Edgar, N. B. (2003). Integrated Catchment Management National Workshop Report, N Z Landcare T rust, C hristchurch. Edgar, N. B. (2006). Commun ity-based Integrated Catchment Management in New Zealand. journal ofthe Australian Water Association 33 (4) : 62-65. H ilden, M . (2000) . T he role of integrating concepts in watershed rehabilitation . Ecosystem Health 34, 39-50. Kellen, S. R. , Mehta, J. N., Ebbin, S. A. & Lichtenfeld, L. L. (2000). Community natural resource management: promise, rheroric and reality. Society and Natural Resources 13, 705-715 Jay, M . (2005) . Recent changes to conservation of N ew Zealand 's nat ive biodiversity. New Zealand Geographer 6 I, 13 1-138. Leach, W. D. & Pelkey, N . W. (200 I). Making watershed partnerships work: a review of the empirical literat ure. Journal of Water Resources Planning and Management 127(6), 378-385. Ministry for the Environment. (2002). The Green Ribbon Awards, Ministry for the Environment, Wellington. Min iscry for the Environment. (2005). Reflections: A Summary of Your Views on the Sustainable Water Programme ofAction, Ministry for the Environment, Wellington. Mitchell, B. (1990) . Integrated Water Management. In: Mitchell B, ed. Integrated Water Management, Bellhaven Press, London, pp. 1-21 . Nimmo, K. (2004) . Lttndcare Group Survey 2003/2004, NZ Landcare Trnst, Christchurch Parkes, M . & Panelli, R. (200 I). Participatory action research in a river catchmen t. Ecosystem Health 7, 84-106. Parkyn, S., Matheson, F., Cooke, J. & Quin n, J (2002). Review ofthe Environmental Effias ofAgriculture on Freshwaters, N IWA Client Report FGC02206, Hamilton. Parliamentary Commissioner for t he Environment. (2004). Growing For

Good: Intensive Farming, Sustainability and New Zealand's Environment, New Zealand Parliamentary Commissioner for the

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Environment, Welli ngton. Phillips, C., Allen, W. & Kilvington, M. (2004). ls knowledge management the answer for ICM? journal ofthe Australian Water Association 31 (3), 63-66. Selin, S. W., Schuette, M. A. & Carr, D. (2000). modelling stakeholder perceptions of collaborat ive initiative effect iveness. Society and Natural Resources 13, 735-745. Tyson, B. , Panelli, R. & Robertson, G. (2005). Integrated Catch ment Management in New Zealand: A Field Reporr from rhe T aieri Watershed . Applied Environmental Education and Communication Journal February, 73-80. Wallace, M . G ., Cortner H . J & Burke S. (1995). Review of policy evaluation in natural resources. Society tLnd Natural Resources 8, 35-47.


. fereed paper

DECISION TOOLS FOR CATCHMENT PLANNING D Watson Abstract

Tobie l. Mo dels in com mo n use by Australia n scientists. AaET AQUALM-XP

The effective use of catchment models in decision making is dependent upon a keen appreciation of uncertai nty and complexity in rhe decision process. N umbers of decision tools are available; however, rhe choice of which rool to use should be driven by the indi vidual needs of each decisio n problem.

~~~r:.:-iN,N

Models commonly used by Australian , , sc1ent1sts (Marston et al, 2002)

FLowzo HYDROLOO

~~~

1

MOOHYDROLO NEX-1 PMWINMOOFLOW RAFTS SMF2D SWAGMAN SWAGMANFARM SWAT THALE S URBS WEC-C

What Do Planning Tools Do?

What Decisions Do We Need To Make? For catchment managers the chief use of planning tools is co help protect source catchments from the impact of potentially threatening land uses; such as intensive agriculture, urban development and ind ustrial development. Effecti ve management decisions require knowledge of how complex natural systems fu nction

~~:~g~

E2 is a software tool that supports construction and ~::imin!SIM running Of WhOJe -Of-Catchment ~Fc - - models for analysis, policy Luos testing and scenario ~5;~ exploration.

~~:t:M.10

WSIBal

In their most basic fo rm , computer models enable us to investigate carchment processes at a scale beyond our limi ted human comprehension. Th ey analyse data that is spread across space and rim e and help us search fo r patterns that wou ld otherwise be impossible to perceive. When this analysis is integrated within a planning process a model becomes a planni ng too l.

NSFM RAP RIPRAP RRL SCL SIMRAT•XL Sed~t TME ....,_. TRl!ND WRAM

AWBM FLOWTUBE GLEAMS IHACRES IQQM LASCAM MACAQUE TOPOO-OYNAMIC WAVES APSIM FEFLOW RORB PERFECT REALM

and how they are affected by land management practi ces. Our understanding, however, is limited by a lack of knowl edge of that co mplex ity. An d to fi ll this information gap we need the help of models.

What Kinds Of Tools Are There? Th ere are many decision cools available . .. lots of them. Th ere are hydrological tools, Geographic Info rmati on Systems (GIS), visualisati on cools and other decision

Table 2. Models availa ble fro m Australi a and the US. AgET AQUALM•XP AQUIFEM-N DATAGEN FLOW20 HYOROLOG IMSOP MIKE-11 MOOHYDROLOO NEX-1 PMWINMOOFLOW RAFTS SMF20 $WAGMAN SWAGMANFARM SWAT THALES URBS WEC-C WSIBal AWBM FLOWTUBE GLEAMS IHACRES IQQM LASCAM MACAQUE TOPOG-OYNAMIC WAVES APSIM FEFLOW RORB PERFECT REALM

Aquacycle BC2C CHUTE CLASS CLASS-COM CLASS.PGM CLASS-SA CLASS-u:JM-10 CMSS

TARGET, ASSESS Dau.Mining QUAL2E SWAT PLOAD WASP EFOC QUAL2K CatchmentSIM EPO-RIV1 E2 BASINS FCFC wcs LUOS HSPF MELS LSPC MUSIC WAMVlew NSFM SWWM RAP RJPRAP RRL SCL SIMRAT-XL S•dNet TIME TREND WRAM

Models available from the USEPA

~

ANNIE BRANCH BSDMS CCAP CGAP DAFLOW DR3M FEQ FESWMS-2DH FOURPT GLSNET HSPEXP HSPF HYSEP IOWDM MEASERR MOOBRNCH MOOEIN NCALC NFF PEAKFQ PRMS SAC SEOOISCH SEDSIZE SPARROW SWSTAT WSPRO

AIRSLUG ANALGWST AQTESTss/ BIOMOC CONTOUR OOtlttmat•

Surface, groundwater and geochemical models from the US Geological Survey

GoPhut GW_Chut HST30 HYDROTHERM JUPITER API MF2K-OWM MF2K-OWT, MOC30 ModtlVltwtr MOOFE BIOMOC BLTM OOTABLES HSPEXP LIMS NETPATH OTIS PHAST PHREEQC PHRQPITZ SPREADBAL-2002 SWPROO WATEQ4F

I MOOFLOW, MOOFLOWP MOOOPTM: PART PHAST PULSE RORA R.UNSAT SEAWAT SHARP SUTRA SUTRA-MS TopoOriw Part:tcleFtow ucooE_ _ Utlllty PIE1 VS20H VS2D1 VS20T. WATEQ4F WTAQ

Models currently available from the E-Water CRC

Aquacycl• BC2C CHUTE CLASS

AGNPS98 ACA DHSVM FIGARO FEQ

Gt nesco GMS HEC-HMS HEC L-THIA MOOBRNCH MOOEIN MTB MP MFI MOC MOC30 MOCDENSE MOOPATH MIKE SHE MIKE21 MIKESWMM MIKE NET

NUARNO NCALC PARADIGM PEAKFQ PORFLOW PumpCom RAINSIM RADMOO RUSLE SINMAP SMS SWM SHETRAN SWRRB SUTRA-GUI STORM TAROEM TRACE123 TOPAZ UEB UP UNCERT WEPP WMS WATFLOOO ZONEBOGT

-

Other models

TIME is a software development framework for creating, testing and delivering environmental simulation models.

mak ing tools such as multi-cri teri a analys is. Some idea of the extent of the models available can be seen in Table I. Column 1 lists a group of models (or their acron yms) which were in common use by Australian scientists in 200 1 (Marston et al, 2002) . Column 2 lists a range of models currently available from the E-Water CRC. This range in cl udes the very useful E2 and T IME softwa re. But fo r the fu ll ca tastro phe, rake a brief look at T abl e 2 which includes other models available, from the USEPA, US Geo logical Survey an d ocher sources. In the end rhe choice of decision rools will be guided by price, by user abili ty, the needs of the task at hand and rhe availability of data. If the data available is sparse it doesn't matter how mathematically co rrect or complex the model is, rhe result can be meaningless. Bu t if there is good data ,iva ilable, even a sim ple model will yield useful results.

Decision tools deal with uncertainty and complexity. This article is an ediced version of a presentation to the A\ Y/ A V ic toria n Bra nch, September,

2006.

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FEBRUARY 2007 93


technical features

Geographic information systems

In the search fo r che right model GIS software can provide a high degree of flexibility and a broad pallet of tools. Among the many available GIS, the ArcGIS and ArcYiew produces from ESRI represent the upper end of functionality, configurability and price, while ocher applications such as Maplnfo and Idrisi are cheaper and yec, depending on the application, may be more than adequate for particular circumstances. For those chat have more rime to invest, there are public domain software products such as Grass and Saga which are supported by vibrant user communities. These products have advanced computational capabilities bur usually require users to have a high degree of skill. T he model outp uts in Figure 1 show a sample catchment constructed usi ng ArcGIS. Individual layers of information representing land cover in figu re I (a) and slope in figure 1(b) were manipulated to form a composite layer in figure 1(c) . Th is new layer shows che relative risk in a catchment from the generation of sediment.

(c)

(b)

(a)

Figure l. A customised model of slope - land cover ri sk created in ArcGIS.

Mose GIS have che ability to auto mate repetitive and co mplex casks with scripts or small programs. ArcGIS and ArcView both ship with an inbuilt Model-builder, a tool which allows che user co drag and drop individual components onto a workspace where models can be rap idly constructed and reseed.

Multi-criteria analysis

Reliable hard data to underpin dacadependenc spacial models is often patchy, but in for mation about a complex system can be expanded in a workshop si tuation, where knowledge from a wide range of experts and stakeholders can be in tegrated. Mul ti-criteri a analysis can be used in these

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Journal of the Australian Water Association


technical features

catchment management workshops to help se c priorities and balance tradeoffs between a range of costs and anticipated benefits. A significant si de benefit of gathering chis information is that participants th emselves are also exposed ro a wide range of information and viewpoints.

e1

refereed paper

A complex decision analysis using the Ecosystem Management Decision Support (EMDS) system which employs Multi Criteria Analysis to rank relative stream condition.

low

_,..._...

u,c1,u,_ ~

Figure 2 is drawn from an American example, where che Ecosystem Management Decision Support (EMDS) system was used ro draw rogecher expert knowledge in a decision framework ro prioritise manage ment options for the protection of riparian zones. Visualisation tools

A major task of the catchment manager is ro communicate the results of model analysis and rhe basis on which decisions are made. Advanced visual isation techniques such as 3D representation (see Figure 3) can help convey very co mplex info rmation. Targeted visual presentations can enhance project reporting and co mmuni cate the importance of a project ro a wide aud ience.

---_

_,., _..,.,...

Figure 2. An example of decision making using Multi-Criteria Analysis.

Choosing Your Model Purely quantitative computer models have rhe advantage of being repeatable bur thei r seemingly reliable results can conceal real uncerraincy and co mplex ity. However, with due judgement, their outputs can be inregrared within a wider decision co ntext. Qualitative tools, s uch as Risk Assessment and Multi-Criteria Analysis, require (and allow) greater participation from all stakeholders. Wh ile the resu lts can be difficult ro measure against targets, they can enhance the resul cs of quantitative assessment and hel p clarify uncertainty within the modelling process.

Conclusions When faced with any decision problem it is important ro give due consideration to the role of decision tools, and in particular, how rhe mix of decision too ls will deal wirh uncertain ty and complexi ty. A plan must be

Figure 3. 3D renderi ng of a Digita l Elevation Model showing stream locations. drawn up char outlines rhe excenr of che uncertainty and complexity, integrates a wide range of information sources and clarifies rhe scale at which space and rime wi ll be created.

The Author

special is ing in catchment decision tools. Ema il: dale.watso n@ecosec.com.au

References Marsron, F., Argen t R., Vertessy, R., Cuddy, S., Rahman, J., 2002, The Status of

Catchment Modelli11g in Australia,

Dr Dale Watson is a sen ior consultant

with Ecos Environmental Consulting,

Cooperative Research Centre for Catchment Hydrology

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technical featurec

catchment management

8

fereed paper

LIMITATIONS OF LIBRARY-DEPENDENT MICROBIAL SOURCE TRACKING METHODS W Ahmed Abstract Over the past 15 years, microbial source tracking (MST) methods have emerged as a managem ent tool for water quality authorities to identify the source of faecal contam ination in receiving waters. The majority of rhe MST method s require the development of a library of target strains or fa ecal indicator bacteria from suspected sources by using various genorypic or phenotypic methods. Phenorypic or genorypic patterns of target strains are then compared to the library ro identify their likely sources. None of th ese librarydependent methods are regarded as a 'gold standard'. Significant limitations include the size and representativeness of the developed library, temporal and geographical stability of target strains, hose specificity of target strains, relative persistence of target strain s in receiving waters and differences in statistical m ethods used. This paper reviews the various assumptions and limitation of library dependent methods currently used for source cracking.

Introduction Faecal indicator bacteria such as Escherichia coli and enrerococci have long b een used to assess th e microbiological qualiry of surface and ground waters (Meays et al. 2004). These microorganisms are found in the intestine of warm-blooded animals in large numbers and their presence in receiving waters generally indicates faecal contamination has occurred from point and non-point so urces CTohnson et al. 2004). In addition, the presen ce of indicator bacteria m ay also infer the presence of life threatening enteric pathogens (Scott et al. 2 002) . Furthermore, faecal contamination nor only pose threats to humans but may results in eco nomic loss due to closure of shellfish harvesting farms in coastal areas. Therefore it is not only imperative to detect faecal contam ination bur also identify the contaminating sources for rhe improved management of water quality and to protect public health from pathogenic microorganisms. Ironically, the sole 96 FEBRUARY 2007

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presence of indicator bacteria in receiving waters d oes nor provide su fficien t information regarding their possible sources (Mcl ellan 20 04). In recent years, several m ethods, collectively known as microbial source cracking (MST) methods have been developed to distinguish the human versus animal faecal contamination in surface waters (Bernherd & Field 2000; C arson et al. 2001; Wiggins eta!. 200 3) . In general these methods could be categorised into library dependent (LO) and library independent (LI) methods. LD methods are based on the fo llowing hypotheses: I. Phenotypic or genorypic attribu tes of ta rget strains (i.e. E. coli or enterococci are commonly used target strains) are hosrspecific; and 2. Phenorypic and genotypic attributes of target strains isolated from environmental samples are similar ro chose found in hose groups.

Assumptions and limitations of librarydependent methods currently used for identifying the sources of microbial contamination. O n rhe basis of these hypotheses, a fingerprint library of E. coli an d/ or enteroco cci isolates from suspected so urces (i.e. humans and various animals) can be developed to predict the sources of unknown environmental isolates by using various multivariate srarisrical analysis (Ritter et al. 2003). The most commonly used genorypic LD methods include pulsedfield gel electrophoresis (PFGE), repetitive exrragenic palindromic PCR (rep-PCR) and riboryping. Commonly used phenotypic LD methods include antibiotic resistance analysis (ARA), carbon source urilisarion (CSU ) and biochemical fingerprinting (BF) . In contrast, LI methods centred around polymerase chain reaction (PCR)

Journal of the Australian Water Association

amplification of stable generic markers. These LI methods largely target hose groups (e.g. human or animal-group specific Bacteroides rRNA genes, human specific viral capsid proteins) or gene specific (e.g. detection of enterococci surface prorei n (esp) gene in enterococci faecium, E. coli toxin gene biomarkers) (Bernherd & Field 2000; Khatib et al. 200 2; Scott et al. 2005). Many of the LD methods have been used around the world to identify the sources of faecal contamination in surface waters (Ahmed et al. 2005; Scott et al. 2004; Whitlock et al. 2002). In Australia, LD m ethods such as biochemical fingerprinting (BF) and antibiotic resistance analysis (ARA) have been used recently in various southeast, Qld local governments (i.e. M aroo chy, Calound ra, Caboolture, Pine Rivers and Gold Coast) and NSW (Po re Stephens). However, questions have arisen regarding rhe reliability of these methods in terms of size and representativeness of the library used (Wiggins et al. 2003), temporal and geograph ical stability of target strains (Gordon 2001), host specificity of target strains (Gordon 2001) and relative persistence/survival of target strains in receiving waters (Desmarais et al. 2002). In this paper, the assumptions and limitations of commonly used LD methods are discussed to provide a better understanding for the application of LO methods in ecological studies.

Assumptions and Limitations of Library Dependent Methods Library size and representativeness Library size and representati veness are two crucial facto rs that need to be considered during development of any LD m ethod. However, these factors (i.e. how many isolates should be included in a library and what constituents a re presentative library) has not been addressed to date. A general consensus is that a library should be large and representative enough to capture as far as possible all the (genotypic or phenotypic) diversity of target strains found in host groups in order to obtain greater success in


technical features

catchment management identi fying unknown environmental strains. However, ir has co be nored rhar, cosr, rime and choice of merhods can significantly limir rhese factors. The size of rhe library should be srarisrically dere rmined based on rhe variabiliry of rhe rarger componenr and likely diversiry in the ecosystem of interest. In practice, however for cost/practical reaso ns most of the genocypic library co nsisting of 35-500 isolates and most of the phenorypic library consisting of 5006000 isolates Qohnso n et al. 2004). To identify the sources of unknown environmental isolates by usi ng a small library is likely co be most misleading, giving a false sense of accuracy (Moore et al. 2005) or a large portion of unidentified environmental isolates. In addition, a small library can signi ficantly compromise representativeness leading co irs inability co capture the temporal or geographical scabiliry of rarger strains (Wiggins et al. 2003). A recent study has reported chat repecirive exrragenic palindromic (rep)-PC R library of E. coli (consists of 1,536 isolates from 13 host groups) was nor represenrarive enough Qohnson et al. 2004). The aurhor used "rarefacrion analysis" for represenrariveness resring and co ncluded rhar size and representariveness are rhe rwo most important factors on rhe predictive ab ili ry and accuracy of LD methods. The representativeness of a library can be measured with either " rarefaction analys is" Qohnson et al. 2004) or "Holdout analysis" (Harwood et al. 2003). Representative resti ng shou ld be performed before applying a library in ecological study. lf the library is not rep rese ncacive, then new iso lates can be added co the library for accuracy and greater success.

that the clonal composition of the coliform species being monitored in a warerbody reflects the clonal composition of the species in host populations responsible for the faecal inputs into rhac water body, co be invalid, and conseq uencly, sraremenc such as - domesric animals are responsible fo r 30% and wildlife for 70% of rhe faecal inpurs co awarer body - may be ambiguous. Harrel et al. (2002) resred a coral of 568 E. coli isolares from carcle, horse, swine and chicken from Idaho and Georgia. A coral of 213 riborypes were fo und among host groups, of which up co 22% were shared among four host groups at two or more combinations. Mcl ellan et al. (2003) reported identical rep-PCR fingerprints in gull faeces an d sewage sampl es (i.e. 29% of isolates from gull faeces were misclassified as sewage iso lates) . A recent study developed a metabolic fingerpr inting database of 4057 enterococci isolates and 3728 E. coli isolates from 10 hose groups (Ahmed et al. 2005). The authors reported chat 44% of en rerococci and 49% ofÂŁ. coli bi ochemical phenorypes (BPTs) were found in rwo or more combination of differe nt host groups. However, 56% of enrerococci

refereed paper

and 5 1% of E. coli BPTs were specific co hoses. It has been argued rhac rhe lack of hose specificity could be related co the discriminatory power of typing methods and/or insufficient sampling regime. Phenorypic methods are more discriminatory than genorypic methods and therefore, iden cify more cosmopolitan isolates. However, ir has co be noted char the mosr discriminatory method pulsedfield gel electrophoresis (PFGE) also identifies cosmopolitan isolates. Temporal stability of target strains within a host

The genorypic or phenoryp ic pattern of target strains should be stable within individual hose group over time. If not, rhen the library needs co be updated regularly if being utilised in eco logical studies. The concept of "transient" (populations which occur only once at a single sampling occasion) versus "resident" (populations occurring multipl e rim es) populations of E. coli in hose groups is well established (Caugan r et al. 1981 ). The authors reported th at only 5.6% (our of 53 MLEE genotypes) of che E. coli isolates from a single human hose were considered

Host specificity of target strains

Ideal target strains (i. e. ÂŁ. coli and/or encerococci) should exhibit a high degree of host specificity. Unfortunately, co mmonly used faeca l indicators in MST such as E. coli do nor exhibit absolute host specificiry and can be transitio nally fo und in multipl e hose groups. These strains have been referred co as "transient" (Harwood et al. 2003) or "cosmopolitan" (Whitlock et al. 2002). Cosmopolitan hose distribution is well documented in E. coli. Mulcilocus enzyme electrophoresis (MLEE) of 270 E. coli from humans and ani mals identified 9% cosmopolitan isolates (i.e. found in more than one hose group) (Ochman et al. 1983). Gordon & Lee ( 1999) reseed E.coli from four orders and ten fam ii ies of mammals in Australia. Identical MLEE genotype of E. coli was found among indi viduals of di fferent taxonomic orders. More recently Barnes & Gordon (2004) has shown char a basic assumption in MST,

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catchment management as "resident" over a period of 11 months. Ochman et al. (1983) reported similar temporal variability where resident E. coli populations from mulriple hose groups accou nted for only 8% of MLEE rypes identified. Another study on the temporal stability of E. coli in hu man, carrle and horse defi ned a persistent ribocype as one that was sampled from an individual in two consecutive sampling events (Anderson et al. 2003) . Ar least one persistent ribocype was observed per human, although only 4 of 36 (11 %) of the ri bocypes observed in the three humans were persistent. In a recent study, individual cattle within a herd were sampled randomly on several occasions. The resident E. coli represented on ly 8.3% of 240 isolates tested from the herd Qenkins et al. 2003). These findings suggest char rhe E. coli obtained from a single host ar a given rime might nor be stable within the same host over rime. However, rhe lack of tempo ral stability could be due to the small num ber of isolates rested in above studies. It has been posrulared char rhe genorypic parrern of target strains is more stable than the phenocypic parrern due to the fact that

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bacterial phenotypes co uld be influenced when rhey exposed to various environmental co nditions (Score et al. 2002). However, chis assumption has not been thoroughly investigated in the light of MST. A recent study demonsrrares char a large phenocypic antibiotic resistance library of enterococci is stable for up to a year (Wiggins et al. 2003) . Similar stability of target strains is also reported in another recent study (Ahmed et al. 2006). The temporal stability of target strai ns remains contradictory and requires stringent evaluation.

Geographical stability Ideal target strains should exhibit geographical stabili ty chat is 'target strains from one population of a host group from one geographical area should be simi lar to those target strains sampled from another population of the same host from another geographical area'. This assumption would certainly circumvent the need for developing regional libraries, instead a nationwide library could be used fo r source cracking. However, geograph ical variation of indicator bacteria especially E. coli has been reported by several studies.

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Scott et al. (2003) used ribotyping method to develop a library of E. coli from human and non human source (i.e. beef cattle, dairy, poulcry and swine) from a broad geographical area and reported that geographical variability exists among nonhuman source. Miller & Hard (1986) tested E. coli strai ns from farm animals and humans and reported chat strains are clonal in nature and not geographically specific. Dontchev et al. (2003) used ARA, ribocyping and PFGE to develop libraries of E. coli and enterococci from three geographical areas. The regional sub-library classified isolates with greater success than the sub-libraries outside the region. All three methods and target strai ns were consistent with these findings. H artel et al. (2002) tested a total of 568 E. coli isolates from cattle, horse, swine and chicken fro m Idaho and Georgia. The authors reported chat the percentage of shared ribocypes within cattle and horse increased with decreased distance between geographic locations. However, for swine and chicken it was quite rhe opposite. Nonetheless, special care should be taken in interpreting the results not only because of the small size

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technical features

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B

Table 1. Advantages and disadvantages of library-dependent (LD) genotypic and phenotypic methods.

Methods

Target Strains

Disadvantages

Advantages

Genotypic methods PFGE

Rep-PCR

Ribotyping

E.coli

1. High discriminatory

Enterococci

2. High reproducibility

1. Require reference library 2. Requires cultivation of target strains

3. Discriminate isolate from multiple host groups 4. Quantitative

4. Labour-intensive

E.coli

E.coli Enterococci

1. 2. 3. 4.

Rapid requires modest resources Require less expertise Discriminate isolate from multiple host groups 5 . Quantitative

3. Library may be temporally and geographically specific

5. Requires special training 1. Require reference library 2. Requires cultivation of target strains

3. Library may be temporally and geographically specific 4. Labour-intensive 5. Results may vary in different laboratories

1. Highly stable 2. May discriminate isolate from multiple host groups

1. Require reference library 2. Requires cultivation of target strains

3. Quantitative

3. Library may be temporally and geographically specific 4. Labour-intensive 5. Req uires special train ing 6. Complex fingerprinting procedure 7 . Requires special tra ining

1. Rapid 2. Inexpensive

1. Require reference library 2. Requires cultivation of target strains 3. Library may be temporally and geographically specific

Phenotypic methods ARA

E.coli Enterococci

3. Easy to perform 4. Require limited training 5. Discriminate isolate from multiple host groups 6. Quantitative CSU

BF

E. coli

1. Rapid

Enterococci

2. High stability 3. Easy to perform 4. Require limited training 5. Discriminate isolate from multiple host groups 6. Quantitative

E. coli Enterococci

1. Rapid 2. High reproducibil ity 3. Easy to perform 4. Require limited training 5. Discriminate isolate from multiple host groups 6. Quantitative

of these reported libraries, bu r also wh en a library developed for one geograph ic area is used fo r source cracking in another geographical area. Primary versus secondary habitat

For target strains, gasrroinresrin al (GI) trace of host groups are considered as primary habi tat while external environments are seco ndary habitat. One of rhe ass umptions in MST is chat the clonal composition of the target strains from environmental samples (i.e. secondary habitat) represents rhe clonal composition of the strains in the host groups (i.e. primary habitats) responsible for faecal inputs. However, several studies have shown char distinct differences exist in £. coli sub-populations between the primary versus second ary habitats. Whittam (1989) rested 113 £. coli isolates from bird faeces by MLEE (i.e. primary habitat) and the lirrer (i.e. secondary habitat) on which they had defecated. Only l 0% of rhe MLEE types

4. Variations in methods in different studies 5. Antibiotic resistance carried on plasmid which can be lost or gained during cultivation and storage 6. Can yield false-positive

1. Require reference library 2. Requires cultivation of target strains 3. Library may be temporally and geographically specific 4. Variations in methods in different studies

1. Require reference library 2. Requires cultivation of target strains 3. Library may be temporally and geographically specific 4. Only metabolically active bacteria can be typed

were shared between both the primary and secondary habitat. Another study used elecrro phoretic types (ET) of E. coli From two septic ranks and their associated residents. The authors reported char £. coli strains from one septic rank were similar to chose of rhe residents. l n co ntrast, strain s recovered from the septic rank of rhe second household were generically distinct from strai ns recovered from its associated residents. Based on the differences between the growth rare and temperature response of these strai ns they concluded char changes in rhe primary and seco ndary habitat of the strains could limit MST (Gordon et al. 2002). T opp et a!. (2003) used ERIC-PCR to compare £. coli isolates from secondary habitat (i.e. swin e manure slurry) with tertiary habitat (i. e. soil inocul ated with the same slurry) . Although the authors reported a major shift in rhe population of £. coli between seco ndary and tertiary habi tat, many types were shared between two habitats. The assumption of primary versus

secondary habitat is controve rsial and requires furth er ex ploration. Survival of target strains in the environment

T o be an ideal candidate for LO source trackin g, a rarger strain should possess certain desirable survival characteristics: I. An ideal rarger strain should nor exhibi t any growth in external environments; 2. T he decay rare of target strains should be co nstant over space and rime; and 3. T he decay rate should be constant betwee n primary and seco ndary habitat. No ne of rhe commonly used target strains meet the des irable survival characteristics for MST . Some authors reported the negative decay rare of£. coli in groundwater (Filip et al. 1987) and seawater (Rozen & Belkin 200 l) whereas ocher studies have reported that under certain conditions E. coli ca n multiply in tropical and subtropical waters

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catchment management (Desmarais et al.). Other studies have also reported that certain non-pathogenic strains of E. coli may bloom in rhe absence of faeca l inputs (Ashbolr et al. 1997; Power et al. 2005). It has been reported by several studies rhat rhe decay rate of£. coli is not constant in water and sediments (Craig et al. 2004). The authors reported significantly lower decay rate of£. coli in sediments rhan that of water. The decay rare of £. coli is also lower in freshwater than seawater, and indeed £. coli appears to grow in sediments (Davies etal. 1995). The persistence of enrerococci in the environments is also controversial like£. coli. Sinton et al. (1993) reported negative decay rare of enterococci in the environments. Some studies have reported that under certain conditions £. coli may replicate in tropical and subtropical environments (Desmarai s et al. 2002). It has also been reported that enterococci can multiply in temperate regions under certain conditions (Anderson et al. 1997). None of rhe conventional faecal indicator bacteria are regarded as universal or possessing desirable criteria for MST. It is important to recognise such limitations of indicator bacteria when choos ing a particular one.

Statistical methods Genotypic or phenotypic fingerprinting data obtained in MST are quire complex. Different multivariate statistical methods have been used to assign rh e host groups correctly and to identify the sources of faecal co ntamination. These include discriminant analysis (DA), cluster analysis (CA), average similarity (AS) and maximum similarity and others (Ritter et al. 2003). T hese methods differ from each other with regard to distribution al assumptions, similarity and predictive capability (Ritter et al. 2003). Therefore, the race of co rrect classification (CC) for host groups may differ significantly depending on the method performed. Ritter et al. (2003) rested seven statistical methods for six libraries (i.e. 3 ARA libraries and 3 repPCR libraries) to investigate the agreement among methods. T he results indicated tl1ac no statistical method performed better than ochers and can significantly affect the performance of LD methods to identify the sources of faecal contami nation .

Conclusions and Future Directions A summary of the currently used LD methods for source cracking and their advantages and disadvantages have been outlined in Table 1. None of the commonly used target stra ins is regarded as universa l or possess all rhe desirable characteristics. Si milarly, no single method is clearly

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superior to ochers (Meays et al. 2004; Scott et al. 2002). Genotypic methods, although highly discriminatory, are generally laborious and/or expensive. In contrast, phenotypic methods are relatively in expensive. However, so me of rhe latter are not highly discriminatory and may lack stabili ty. The performance of the majority of lib rary-dependent methods reviewed was limited by their size and representativeness, stabi li ty, discriminatory power and statistical analyses. More research is needed co evaluate various methods in terms of above assumption and limitations. Library independent methods such as host specific PCR of Bacteroides, virus specific PCR, gene specific PCR of£. coli toxin genes and host specific enterococci surface protein (esp) marker in Enterococcus faecium offer many advantages over LD methods. These methods circumvent the need for developing a library, are rapid and easy to perform and have shown higher accuracy in method comparison studies (G riffith et al. 2003) . However, these methods are under development and nor quantitative. Some of the methods ca nnot differenriace among multiple host groups. For example, specific primers have been developed to detect human and ruminant specific Bacteroides. Ruminant specific primers will derecr faecal contamination from cattle as well as deer. Moreover, primers are nor available for all animal species. The preva lence of toxin genes among £. coli isolates is quire low and therefore a cultu ral enrichment step needs ro be performed prior to testing by PCR. The geographical variation of the esp marker and human specific Bacteroides has no r been evaluated completely. Methods need to be carefully selected depending on study objectives. Ir is also recommended that a combination of different methods from a 'MST toolbox', where possible, should be used to obtain confirmatory results. For example, LI methods can be used to detect human contam in ation in a catchment, followed by using a LD method to confirm/quantify human contaminatio n or vice versa. Any error in identifying rhe sources may nor be acceptable for regulatory purposes. The advance in molecular techniques such as the q-PCR or generic array rhar measure pathogens is under development and will certai nly en hance the MST science in near future.

The Author

Dr Warish Ahmed has had a career in identifying the so urces of faecal pollution (known as BST or MST) in aquatic environ ments. He is curren tly working as a consultant and developing a 'Toolbox approach' to identify rhe sources of faecal

Journal of the Australian Water Association

. . ..

.....

pollution in Queensland's waterways. Contact him at rhe Faculty of Science, Health and Education, University of rhe Sunshine Coast, Maroochydore DC 4558, Queensland, Australia. Email: shuhat@yahoo.com

References Ahmed, W. , Tucker, J., Harper, J., Neller, R. & Karouli, M. 2005, 'Host species-specific mecabolic fingerprint database for enterococci and Escherichia coli and irs application to identify sources of fecal contamination in surface waters', Applied and Environmental Microbiology, 71, pp. 4461-8 . Ahmed, W., Neller, R. & Karouli, M. 2006, 'Comparison of the efficacy of an existing versus a locally developed metabolic fingerprint database ro identify non-point sources of faecal contamination in a coastal lake' , W'ater Research, 40, pp. 2339-48. Anderson, M.A., Whitlock, J.E. & Harwood, V.J. 2003, ' Frequency distributions of Escherichia coli subrypes in various fecal sources: Appl ication ro bacterial source tracking methods' , In American Society fo r Microbiology General Meering, Washington, D C. Ashbolr, N .J. , Dorsch, M.R., Cox, P.T. & Barnes, B. 1995, 'Blooming£. coli, what do they mean? In coli.forms and E. coli Problem or Solution. Kay, D., And Fricker, C. (eds.) Cambridge, UK: The Royal Society of Chemistry, pp. 78-85. Bernhard, A. E. & Field, K.G. 2000, 'Identification of non-point sources of fecal pollution in coastal waters by using hostspecific 16S ribosomal D NA generic markers from fecal anaerobes', Applied and Environmental Microbiology, 66, pp . I 58794 . Carson, S.A., Shear, B.L., Ellersieck, M.R. Afsaw, A.M .H. A. 200 I, 'Identification of fecal Escherichia coli from humans and an imals by Riboryping', Applied and Environmental Microbiology, 67, pp.1503-7. Caugant, D.A., Levin, B.R. & Selander, R.K. 1981, 'Generic diversity and temporal variation in the E. coli population of a human host', Genetics, 98, pp. 467-90. Craig, D.L., Fallowfield, H .J. and Cromar, N.J. 2004, 'Use of microcosms ro determine the persistence of Escherichia coli in recreational coastal water and sediment and validation wirh in situ measurements', Journal ofApplied Microbiology, 96, pp. 922-30. Davies, C.M., Long, J .A., Donald, M & Ashbolr, N. J. 1995, 'Su rvival of fecal microorganisms in marine and freshwater sediments', Applied and Environmental Microbiology, 96, pp. J 888-96. Desmarais, T. R., Solo-Gabriele, H.M. & Palmer, CJ. 2002, ' Influence of soil on fecal indicaror organisms in a tidally influenced subtropical environment ', Applied and Environmental Microbiology, 68, pp. 1165-

72. Donrchev, M., Whitlock, J.E. & Harwood, V.J. 2003, ' Riboryping of Escherichia coli and enterococcus spp. ro determine the sources of fecal pollution in natural waters', American Society for Microbiology General Meeting, Wash ingron, DC.


technical features

catchment management Filip, Z., Kaddu Mulindwa, D. & Milde, G . 1987, 'Su rvival and adhesion of some pathogenic and facultative pathogenic m icroorganisms in grou ndwater', Water Science and Technology, 19, pp. 1189-90. Gordon, D.M. & Lee, J. 1999, 'The genetic structu re of enteric bacteria from Australian mammals', Microbiology, 145, pp.2663-71. Gordon, D.M. 2001 , 'Geographical structure and host specificity in bacteria and the implications for tracing the source of coliform contamination', Microbiology, 147, pp. l 079-85. Gordon, D.M., Bauer, S. & Johnson, J. R. 200 2, 'The genetic structure of Escherichia coli populations in prima ry a nd secondary habitat', Microbiology, 148, pp. l 513-22. Griffith, J. F., S. B. Weisberg and C. D . McGee. 2003, 'Evaluation of microbial source tracking methods using mixed fecal sou rces in aqueous test samples', Journal of Water and Health, l , pp. I 41 -51. H artel, P.G., Summer, J .D. , Hill, J.L., Collins, J.C., Enrry, J.A. & Segers, W. I. 2002, 'Geographic variabi lity of Escherichia coli isolates from animals in Idaho and Georgia', Journal ofEnvironmental Quality, 3 1, pp. 1273-8. H arwood, V.J., Wiggins, B., Hagedorn, C., Ellender, R.D. , Gooch, J., Kern, J., Samad pour, M., Chapman, A.C. H ., Robinson, B.J. & Thomson, B.C. 2003, 'Phenoryp ic library-based microbial source rracking methods: efficacy in the California collaborative study', journal of Water and Health, 1, pp. 209-24 . Jenkins, M .B., Hartel, P.G ., Olexa, T.J. & Scuedeman n, J.A. 2003, 'Putative temporal variabiliry of Escherichia coli riborypes from yearling steers', journal of E11vironme111al Quality, 32, pp. 30 5-9. J ohnson, L. K., Brown, M.B. , Carrut hers, E.A., Ferguson, J.A., Dombek, P. E. & M. J. Sadowsky, M.J . 2004, 'Sample s ize, library composition, and genotypic diversiry among natural popula tions of Escherichia coli from different animals influence accuracy of d etermining sources of feca l pollution ', Applied and E11vironmeutal Microbiology, 70 , pp. 4478 85. Khatib, L.A., Tsai, Y.L. & Olson, B.H. 2002, 'A biomarker for the identification of cattle fecal pollution in water using t he LTlla toxin gene fro m enteroroxigenic Escherichia coli; Applied Microbiology and Biotechnology, 59, pp. 97- I 04. Mclellan, S.L., D aniels, A. O. & Salmore, A. K. 2003, 'Genet ic characterization of Escherichia coli populations from host sources of feca l pollution by using D NA fingerprinting', Applied and Environmental Microbiology, 69, pp.2587-94 . Mclellan, S. L. 200 4, 'Genetic diversity of Escherichia coli isolated from urban rivers and beach water', Applied and Environmental Microbiology, 7 0 , pp. 4658-65. Meays, C. L., Broersma, K., Nordin, R. & Majumder, A. 2004, 'Source t racking fecal bacteria in water: a critical review of current methods', journal of Environmental Management, 73, pp. 71-9. Miller, R.D. & H arri, D.L. 1986, ' Biotyping confirms a nearly clonal population structure in Escherichia coli', Evolution, 40, pp.1 - 12. Moore, D. F., H arwood, V.J. Ferguson, D.M. , Lukasik, J., H annah, P., Getrich, M. & Brownell, M. 2005, 'Evaluation of antibiotic resistance analysis and ribotyping for identification of fecal pollution sources in an urban watershed. journal ofApplied Microbiology, 99, pp. 618-628. Ochman, H. , Whittam, T.S., Caugant, D.A. & Sela nder, R.K. 1983, 'Enzyme polymorphism and genet ic population structure in Escherichia coli and Shigella; journal ofGeneral Microbiology, 129, pp. 2715-26. Power, M.L., Littlefield -Wyer, J ., Gordon, D.M ., Veal, D .A. & Slade, M. B. 2005, ' Phenotypic and genorypic characterisatio n of encapsulared Escherichia coli isolated from blooms in rwo Aust ralian Lakes', Environmental Microbiology, 7, pp. 631-40. Ritter, K.J. , Carruthers, E., Carson, C.A., Ellender, R.D., Harwood, V.J., Kingsley, K., Nakatsu, C., Sadowsky, M., Shear, B., \'v'est, B., Whitlock, J.E., Wiggins, B.A., Wilbur, J. D . 2003, 'Assessment of statistical methods in library-base approaches in microbial source tracking', Journal of Water and Health, I , pp. 209-223. Rozen, Y. & Belkin, S. 200 1, 'Survival of enteric bacteria in seawater', FEMS Microbiology Review, 25, pp. 513-29 Scott, T.M., Rose, J.B., Jenkins, T.M., Farrah, S.R. & Lukasik, J. 2002, 'M icrobial source tracking: current methodology and future directions', Applied and Environmental Microbiology, 68, pp. 5796-803. Scott, T.M., Parveen, S., Portier, K.M., Rose, J .B. , T amplin, M .L., Farrah, S. R., Koo, A. & Lukasik, J. 2003, 'Geographical variations in ribotype profiles of Escherichia coli isolates from humans, swine,

refereed paper

poultry, beef and dairy carrle in Florida', Applied and Environmental

Microbiology, 69, pp. l 089-92. Scott, T. M., Caren, J., Nelson, G. R., Jenkins, T.M. & Lukasik, J. 2004 , Tracking sources of fecal pollution in a South Carolina Watershed by ribotyping Escherichia coli: A Case study', Environmental Forensics, 5, pp. 15-9. Scott, T .M. , Jenkins, T.M. , Lukasik, J. & Rose, J.B. 200 5, 'Potential use of a host associated molecular marker in Enterococcus faecium as an index of human fecal pollution', Environmental Science and Technology, 39, pp. 283-7. Sinton, L. W., D onnison, A. M. & and H astie, C.M. 1993, 'Faecal streptococci as faecal pollution indicators: a review. Part 11. Sanitary s ignificance, survival and use', New Zealand journal ofMarine and Freshwater Research. 27, pp. 11 7-37. Topp, E., Welsh, M., T ien, Y. -C., D ang, A., Lazarovitz, G., Conn, K. & Zhu, H. 2003, 'Strai n dependent variability in growth and s urvival of Escherichia coli in agriculcural soil', FEMS Microbiology Ecology, 44, pp. 303-8. Whitlock, J. R., Jones, D.T., & H arwood, V.J. 2002, ' Identification of the so urces of feca l coli forms in an urban watershed using antibiotic resistance analysis', Water Research, 36, pp. 4273-82. Whittam, T. S. 1989, 'Clonal dynamics of Escherichia coli in its natural habitat', Antonie V1111 Leeuwenhoek, 55, pp. 23-32. Wiggins, B. A., Cash, P.W., Creamer, W.S., Dart, S.E., Garcia, P.P., Gerecke, T.M ., H an, J., H enry, B.L., Hoover, K.B., Johnson, E. L., Jones, K.C., McCarthy, J.G., McDonough, J .A., Mercer, S.A., Noto, M . L. , Park, 1-1. , Phil lips, M.S., Purner, S.M. , Smi th, B. M., Stevens, E. N. and Varner, A.K. 2003, 'Use of antib iotic resistance analysis for representativeness testing of multi-watershed libra ries', Applied and Environmental Microbiology, 69, pp. 3399-405.

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FEBRUARY 2007 101


NO DIG DOWN UNDER 24th International Conference, Brisbane 2006 Report by EA (Bob) Swinton The Australasian Society of Trench less Technology celebrates 25 years of operation, under the banner of rhe International Society for T renchless Technology, and rh is international conference amacred 1020 delegates, half of rhem from overseas. The ope ning address was from Josephine Parker MBE, a promi nent civil enginee r from UK, honoured for her voluntary work in thi rd world countries. Ar rhe opening breakfast fu nction, she was deliberately light-hearted , bur she focused on an important theme, the dearth of engineers, fo r all aspects of civil engineering. (Her add ress had good ideas and will be pu blished in a later issue of Water). T h is conference covered not jusr the tech niques of horizontal directional dri1ling, pull-through of pressure pipes and cables, and pipe-jacki ng of sewers, but a wide spectrum of rhe 'underground' business, includ ing cond ition assessment, infiltration, asset management, rehabilitation and renewal of sewers, detectio n and mapping of underground services and sessions on alliance contracting, risk allocation an d insurance. Most of rhe presentations are now posted on the ASTT web-sire. Some selected papers are published in rhis issue of Water.

Horizontal Directional Drilling and Rehabilitation Naturally there were numbers of papers devoted to rhe technology, backed up by so m e massive exhib its in rhe exhibi tio n. Papers extended fro m case studies (such as rhe Hallam Bypass Sewer, Water, Novembe r 2006) ro high-tech guidance rechnology, such as rhe use of high precision optical gyroscopes. In a keynote speech Stephe n Loneragan, GM of Directional Drilling ar rhe Lucas G roup, reviewed future directions and world trends. A useful series of papers, mainly from exh ibitors, span ned various methods of pipe repair, CI PP, pipe bursting, co nnection of laterals, to spray re-lining of pressure pipes.

102

FEBRUARY 2007

Water

170WN U~R UXJfo Condition Assessment A number of papers foc used on inspecti on strategy, so me citing case examples ranging from H ong Ko ng to the Ruh r. Bruce Hutton and Da niel Faccio of Brisbane Water exp lain ed how they are app lying the German asset management program, AQUAVERTMIN . They have broken down their tru nk sewers and reticulation into a num ber of cohorts based on the parameters of similar construction, flow co nditions, characrerisri cs of the sewage, ere. using previous experience wirh each cohort to pred ict risk of fa ilu re, th en adding in rhe likely conseq uences (eg, high costs of fail ure in a commercial zone) then using linear programming to prioritise CCTV inspections and rehabili tation programs. Robert Stei n, from Stein and Partners, Bochum, Germany, explained their software package which applies fuzzy logic to determine priorities for re newal or rehabilitation. Th e biggest difficulty is differe ntiating the risk between one major damage versus a series of minor damages. His package aims to quantify rhe STATUS of a sewer, by raking in al l rhe fac tors such as material , diameter, so il properties, load, depth of cover. Regrettably, rhe 20 years of CCTV inspecti on data available in a European context is, in his opinion, 20% fl awed because there has been no rigid code of reporting defects. Th e ma tter of a consistent reporting code fo r CCTV inspection has been caken up by WSAA, and David Cox outlined the 2006 upda te which has been posted on rheir web-sire. None-the-less, operator fatigue is still a major factor.

Journal of the Australian Water Association

Ian Vickridge, B&V, summarised his work on Hong Kong water ma in s, with 3000 km to be rehabilitated in 15 years. Remote Field Technology and Near Field T echnology were used to meas ure resid ual wall thickness in steel pipes. H e pointed our char factory-applied bitumen coating is usually satisfactory bur rhe hand coating fo llowing a weld can be suspect. A system which mi ght operate in an operating main is under trial, rhe difficulty being char rhe fi rst trial reported no defects! A paper from Luisiana Tech reported on research on pulsed ground penetrating radar from a robot tracking inside nonconductive pipes. The pulse is only 0.2 picoseconds, and the reflected waves are analysed by the software to give both wa ll thickness an d presence of voids.

Asset Management The theme of cond ition assess ment was continued into discussions on asset management (A/M). If assets are supposed to have a 100 year life, then we should be replacing at least I% per year, but most auth orities do only a fracti on of that. Some com ments: W hat hi storical records have we gor to calibrate predictive models? South Africa laid an experi mental sewer which was dug up in ten years to assess rhe performance of materials. Vic EPA apply cri minal proceedi ngs if due diligence is not followed, bur how can lawyers assess this? A useful tool to pin point weak sewers is Ill , bur unforrnn arely with rhe drought, there hasn't been enough rainfall to do the analys is. So much industry re-organisation has happened rhar there are few engineers left with corporate knowledge. H istory is so viral that WSAA and Global Water Research Coalition are scarring a project bur they are enco untering reluctance to share data . Warre n Adams (MWH) reviewed global tre nds in A/M, com paring USA, UK, NZ, Australia. So far, Australians are world leaders, but USA is experienci ng an explosive growth, with mass ive investment in data analysis, modell ing and decision support.


technical features

Josephine Parker reviewed the development of AIM in U K as a crossindustry discipline, covering railways, roads, power, gas as well as water. The Institute of Asset Management has sec up skills and competency standards with seeps for career development an d the b asis for accreditation. She later noted that OFWAT has introduced TBL to en courage factoring in of externalities. Peter Gee reviewed WSAA's bench marking of AIM, first done in 2004. Ic allows an auth ority to see how it compares with others , in each of the seven pillars of AIM. Even so, AIM is not fu lly recogn ised at corporate level. There is poor succession planning , but a formal accreditation system will help. Their fir st exercise has sh own up a long list of key opportunities and the survey w ill be repeated in 2008.

Sustainability: Comparing Open-cut and Trenchless Technology in Urban Situations Joseph ine Parker ann ounced that the UKWIR has do ne a des k-top review of direct and indirect costs. Because of commercial sensitivity for some of these figures , global benchmarking was also used. ( It was noted that on average only 1-2% was allocated for planning and design!). For direct costs TT was usually more expensive than trenchi ng and rehabilitation but w hen indirect costs were factored in , th e comparison was reversed. Some examples of indirect costs were traffic dislocation and delays, plus wear and tear on vehicles on damaged toads . Add compensation fo r loss o f profits for adjacent businesses and env ironmental factors such as waste, spo il , n oise, dust, increased traffic ex hausts in q u eues, and damage to street treescapes . Sign ificant reduction in house values coul d b e costed , p lus social costs and ' negative image' in local press. T here was a clear message that comparison of direct costs alone was shore-s ighted . Sam Ariaramam , Arizona State University, anoth er keyn ote speaker, reinforced the message on a world scene. He stated that TT would not be adopted by local governments u nless we demons trate t he p olitical advantage to chem o f the sustainable approach. In G ermany water pipes are laid 50% by TT but in Japan , TT is always adopted b ecause of so many restrictions on excavatio n. An oppos ite case was Ge neva, wh ere the Council is so 'anti-car' that

they couldn't care less about disrupting traffic by excavations!

Mapping the Underworld (MTU) The brake o n further applicati on of TT in urban situatio ns is lack of knowledge of what is already under th e road. Most cities have grown like Topsy, and the space under a road h as been regarded as a p ublic good, i.e. firs t in, best dressed. Research in Germany has shown ch at the risk of damage to existin g infrastructure by excavator is some 15 times that by H DD. It can b e minimised by (expensive) hand digging, whereas HDD requires either an accurate historical map or app lication of sensor technology, such as C P R, EM. Of course HDD can lay a new pipe deeper, clear underneath che comp lex of ex istin g pipes, conduits and cables, but this means cbe pipe is less accessible for repair or future connect ions. Chris Rogers, Birmingham, UK, ou clined their project which is comb ining the multi-disciplinary ski lls of seven UK universities with the ai m to develop a multi-senso r device to detect 100% of buried utility services. The aims are: userfr ien dly 3D with operator-friendly readou t, integration of data in a unified fra mework, remote i. d . tags attached to the pipes, netwo rk interface with stakeholders . To ensure chat they were tackling the ri ght problems th ey asked stakeholders what was their percept ion of acceptable accuracy, horizontal and vertical. In general +/- 300 mm is regards as acceptable. There were many other p apers describing advances in such techniques, including one simple means of developing a 3D picture by placing a large plasti c mac on che surface, marked with a grid to enab le the stereo sensor to track accurately. A continuing theme was sustainable use of underground space which up to now has been haphazard. Jim Reeves, Brisbane Water, appealed fo r both vertical and horizontal land use planning. SE Q u eenslan d is faced with che need for infrastructu re to cop e wi t h 1000 extra inhabitants each week. On the surface multi-storey expansion is happening bur in b rownfield exp ansion che underground assets are ou t of sighr. He was one of those who called for more allian ce contracting.

Contracting Arnold Dix (QUT) a lawyer specialising in reducing corporate risks, explained the reluctance of the insurance industry to reinsure Trenchless Technology d ue to th e high er risk of operation 'in the dark' . However, The T IC Alliance in Europe has d rafted a Code which stipulates many con ditions for both client and contractor to assure better risk reduction . The world response is that major con tractors had no issues, but small contractors were not even aware of che code. Australia is already a fore-runner in Risk Management so it is quite simple to adopt. One contractor made the plea that if the client will not provide a thorough geo-tech su rvey to the ten ders, th en any honest quotation has to embody that risk.

Case Studies There were case studies from overseas, but Aust ralian contributio n s were notable. Altho ugh n ot a water p ipe, one of the 2006 Awards was given to Atteris PIL for th eir innovative shore crossing for the Otway gasfield project. Ar a portion of th e National Park o n the V icto rian southern coast near Port Campbell a 1200 mm cas ing was drilled from cl iff top down under che surf zo ne to connect, by a threaded connectio n, to the b ell-mouth of the undersea pipeline. Brisbane's Interceptor Sewer, and the Hallam Valley Main Sewer (Victoria) are complete and th e Perch desalination pipeline, at 140 ML/d, is the third largest in the world. 26 km of trunk ma ins were la id by pipe-jacki ng through an environmentally sensitive area which included five tunnelli ng zo nes. For the Perch Main Sewer, 865 m has been replaced and TT was 25% cheaper in che san dy soil becau se there is n o need for sheet pilin g o f a trench. The Lake Macquarie main sewer reh abilitation was unusual in chat most of it was below lake level, and some manholes were actually in the lake itself. Sydney Water provided five examples where TT won out over traditio nal methods.

Conclusion The conference ended with a firm note that the next one, in Rome, September 2007, muse involve fi nancial agencies and insurance brokers so as to address their points of view on risk management and risk allocation.

Journal of the Australian Water Association

Water

FEBRUARY 2007 103


CONTRACT INSURANCE: LESSONS FROM THE WORLD'S TUNNELLING INSURERS A Dix

.

----

Abstract

The world's reinsurers are ulcimacely responsible for the lions' share of the After a number of rnnnelling disasters the financial burden when projects fail. O ver International T unnel Insurers Group, the last decade or so the underground • High risk type construction methods comprising the major re-insurance construction secro r boomed (and continues companies, has formulated a Code: In • Trend towards design + build contracts to boom) as cities exploit the undergroun d effect, no proper Risk Managemenr, no • One-sided contract conditions for their transporration and utili ty needs. insurance, so no projecr. There are lessons • Tight construction schedules In order for these massive (often multithere for ocher water infrastrucrnre projects. • Low financial budgets billion dollar projects) co proceed, experrise, Introduction resources, and demanding fu nctional • Fierce competition in construction industries requirements are mixed with political As Australia enters a major water Figure 1 promises, tight budgets, fierce commercial infrastructure construction ph ase, the stress competition and right cimeframes. The of onero us delivery rimelines, lack of result over the preceding decade or so has sufficient expertise, aggressive rendering been unprecedented losses due co construction fail ures, co llapses, and novel co ntractual and fi nancial frameworks, coupled with che delays and ocher preventable errors. political imperatives associated with the successful delivery of such General Tre nds In the Tunnelllng Industry

massive water projects makes che lessons from recencly failed underground construction projects of relevance. Interestin gly ch e lessons learn t in underground infrascrucrnre fai lures resul ted in higher premiums for less cover, all che way co no cover at any prem ium, or co unsophisticated (or perhaps very sophisticated) adv iso rs procuring inappropriate cover. The marker has responded by creating a gulf between informed and appropriate risk management (including insu rance) and demonstrably deficient risk management and insurance. Unforrunacely in at lease one current major Australian water project the same deficient paccern of risk management (including insurance) has now emerged. (Derails must remain confidential for legal reasons) This paper argues char che same factors which conspired co bring the rnnnell ing sector into an insurance crisis muse be actively managed co successfully develop the projects comprising Australia's current water infrastructure boom.

The world 's reinsu rers faced a crisis - they seriously considered withdrawing the availability of their capi tal from this marker sector

Major Tunnel Losses since 1994 PROJECT

CAUSE

LOSS

1994 Great Belt Link, Denma rk

Fire

USS 33mlo

1994 Munich Metro. Germany

Collapse

US$

1994 Heathrow Express Link. GB

Collapse

USS 141 mlo

1994 Metro Taipei. Taiwan

Collapse

US$ 12 mlo

1995 Metro Los Angeles, USA

Collapse

USS

1995 Metro Taipei, Taiwan

Collapse

USS 29 mlo

1999 Hull Yorkshire Tunnel , UK

Collapse

US$ 55 mlo

1999 TAV Bologna - Floren ce, Italy

Collapse

US$

1999 Anatolia Motorway, T urkey

Earthquake

US$ 115 mio

2000 Metro Taegu. Korea

Collapse

US$ 24 mio

4mlo

9 mlo

9 mlo

Lessons from the Underground Construction Sector A space of massive project failures in che underground construction sector promp ted action from the insurance industry. The sirnacion is summarised on a series of slides prepared by Munich re- insurances Mu nich office on the subject (Figures I, 2, 3) and graphically illustrated by so me major collapses overseas (Figures 4, 5, 6).

The International Tunnel Insurers Group Code: Proper risk assessment is essential.

Figure 2 Major Tunnel Losses since 1994 CAUSE

LOSS

2000 TAV Bologna - Florence, Italy

Collapse

US$ 12mio

2002 Taiwan Hig h Speed Railway

Collapse

US$ 30 mlo

2002 SOCATOP Paris, France

Fire

USS

2003 Shanghai Metro, PRC

Collapse

US$ 80 mio

2004 Singapore Metro. S'pore

Collapse

t.b.a.

2005 Barcelona Metro, Spain

Collapse

t.b.a.

2005 Lausanne Metro, Switzerland

Collapse

t.b.a.

2005 Lane Cove Tunnel, Sydney

Collapse

t.b.a.

2005 Kaohsiung Metro, Taiwan

Collapse

t.b.a.

This paper has been developed from rhe presentation which Professor Dix gave ro rhe No Dig Down Undtr conference, Brisbane, November 2006.

Figure 3 104 FEBRUARY 2007

Water

Journal of the Australian Water Association

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technical features

.,, I Q

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0

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Figure 5. South Korea, Deago Metro Collapse, 2000.

Figure 4. Shang hai Metro Col lapse - 2003.

(several insurers d id withdraw) and remaining insurers began ca refull y analysing the project failures. The remaining reinsurers fo rmed a sector specific insurers group. Known as ITIG (Internacional T unnel Insurers Group) it comprised the key global players incl uding Allianz, Gerl ing, Mun ich Re- insurance, Roya l and Sun Alliance, Swiss Re, Zurich. IT IG identi fied co mmon themes in the projects wi th major losses. Puc simply these proj ects all suffered from a lack of systematic risk assessment - and more particularly the risks associated with lack of expertise, unrealistic timeframes, political in te rference, poor proj ect preparation, inappropriate sharing of technical info rmation and the risks, these causes being substantially underestimated or in some instances totally ignored. IT IG then engaged risk assessment experts and joinrly form ulated a code of practice fo r undergrou nd works with rhe British T unnelling Society - a code which has now been internationalised and translated into several languages. The code now fo rms a base line requirement fo r project risk assessments fo r procuring reaso nably priced and appropriately scoped insurance fo r most major undergro und co nstruction projects.

run nel experienced a fata l collapse - Fairfax News, 24 August 2005, reported: "the ... .consortium was pushing the Roads and T raffic Auth ority ro give them clearance fo r a December 19 opening, I O months ahead of their co ntracted completion date. Opening so fa r ahead of time wou ld have been a remarkable fear, earni ng chem a huge financial bonus" In 2005 there was another collapse, chis time at rhe Lane Cove tun nel, which although small by co mparison wi th co llapses overseas, still led co substantial losses. Th is highlights rhe importance of carefu lly considering the impacts of carefu lly crafted co nrracrs on the risk profile of a project. With these factors in mind a closer examination of the code is warranted.

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Failure to meet the requirements of the code can stop projects no insurance - no fi nance - no project. For example, earl ier this yea r the Andes Link co Bogota became a possibility after georechnical in for mation from a new pilot tunnel was analysed. Th e inabili ty co obtain insurance was rhe main reaso n char previous project proposals had fa iled to secure insurance, and therefore failed.

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Water

FEBRUARY 2007 105


technical features

Key Features of the ITIG Code

Expertise and availability

World Response?

The code entrenches systematic risk management. Th e code does not demand that it be followed - merely that it - or an equivalent (or better) methodology for systematic risk assessment - be adopted and used on projects.

The technical and contractual competency of clients is a p re-requisite co insurance being provided. This extend s to including named individuals and confirmation of their availability.

The international response to these new requiremen ts also provides an insight into the markets' response ro the insu rers' requirements.

In this way che insurers hope char there will be more informed risk caking, better "relat ionships" between project participants and that thereby the actual risks on che projects will be reduced. The main cheme of che code is char insurance not to b e used as: "contingent single mitigation measure in major infrastructure works" . Key features of the code include: • Management of risk (not elimination) • Quantification (program and cost implications) • Development of pro-active risk management strategies • Dynamic "risk register" • Articulating responsibil it ies for risks There are also several fundam ental insu rance mandates chat should be of interest to major water in fras tructure projects in Australia.

Time and budget During the Project Development Phase sufficient time and b udget muse be provided to "Investigate and d emonstrate technical viability of project. .... prepare d esigns appropriate for contract form to be adopted ... ".

Geotechnical data Geocech nical conditions must be part of contract to allow ready comparison with conditions actually encou ntered.

Data exchange C lient is responsible for transfer of data between different d esign teams .

Change management • D es ign changes must have impact on techn ical risks and proj ect risks evaluated • Insurers m use be p rovided with design change assessments

Germany • High level of interest amongst investors and p rincipals • Investors see increased transparency in the whole procuremen t and co nstruction p rocess • Major co ntractors have no issues with the Risk Managemen t processes being suggested, they would consider their inhouse systems superior to those suggested in the code • Smaller co ntractors are not, however, aware of the code

Hungary T he first use of the code in Eastern Europe will be on rhe Budapest Metro .

Croatia There will be a seminar of Eastern European Nations to d iscuss the role of the Code early in 2007.

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technical features

Spain

• Lack of expertise

There was a presentation of the code of practice co rhe marker in December 2006. The response is expected by the end of rhe first quarter 2007.

• Unfair conrracrs • U nrealisric rime pressure/incentives • Poor georechnical ground data

Asia

then perhaps these issues are real and we should rake note.

• Well accepted in Singapore, Malaysia and Chinese Hong Kong • Interest in Thailand • Chinese Taiwan, Korea, China: interest has only just begun, the whole issue of Risk Management is getti ng a higher profile in these countries.

Australia Implementation is common on major projects. The existence of an acceptance Risk Management Standard makes implementation of the risk management aspect of the code quire simple. Today in the Australian tunnelling industry rhe issues identified in the code are real and immediate. • Screeched capacity of experts • Multiple complex jobs on right delivery schedules • Financial incentives for early completion In Australia the underground infrastructure sector is respo nding co these challenges by main raining and enhancing the culcu re of systematic risk management. However the recent Lane Cove tu nnel collapse and the current Supreme Court proceedings in Western Australia between Leigh cons and the Public Transport Authority demonstrate char risk management and insurance remain an area fraught with challenges for the underground infrastructure secror. lf the water infrastructure construction boom fails co address these co mmon major infrastructure risk issues it coo faces the prospect of reduced confid ence by rhe insurance marker, potentially leadi ng co: • Uninsurable projects • Higher prem iums

Insurance will remain a precond ition to the viabili ty of all major water projects. Water- wise now includes having an eye co ocher major infrasrrucrure sector experiences on the special risks of doing these projects in the expertise-starved, competitive and poli ticised world of major project delivery in the 2 1st century.

Reference International Tunnelling Code ofPractice is hosted by rhe In ternational Association of Engineering Insurers at www.imia.com or at www.arnolddix.com

The Author Adj Prof Arnold Dix provides advice on project and decision risks for major infrastructure. He is both a lawyer (Barrister and forme r Partner DLA Phill ips Fox) and Adj. Prof Engineering QUT. He is rhe Chairman of Comracrual Practices Co mmittee ITA (UN affi liate organisation) and has been a "technical" legal advisor co rhe water industry and underground infrastructure sectors for 20 years. Contact counsel@arnolddix.co m

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• Less cover • Insurer-imposed procedures for managing risks on major water projects.

Conclusions The lase decade of underground infrastructure failures led co a series of risk mitigation strategies wh ich the world's re-insurers are imposing on projects globally, as a pre-condition co appropriately priced and scoped insurance cover. Without insurance most projects will not proceed. T he sheer number, bread ch and complexity of Water lnfrascrucrure projects currently proposed or under construction in Australia wi ll create a range of risks nor dissimilar co chose experienced in the underground infrastructure secto r.

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W ith fina ncial constraints, eight rime frames, new delivery methods (contractual) and a global shortage of expertise the major infrascrucrure water sector should consider che measures contained in rhe Internacional Code of Underground Construction from ITIG co bolster their management of project delivery risks. Furthermore there is already evidence chat the insurance demands of these projects may be beyond rhe expertise of traditional insurance professionals. Recent history has demonstrated chat even in the water sector in Australia there is a lack of high level expertise co procu re che appropriate insurance.

If insurance compan ies have identified a direct relationship between runnel failure and: Journal of the Australian Water Association

water

FEBRUARY 2007 107


MAJOR PIPE JACKING FOR PERTH DESALINATION AND MAIN SEWER PROJECTS M I Oliver, D Boland, M J MacCormick, J C Bower Abstract

Table 1. Design Risks and Mitigation.

In 2005 and early 2006, pipe jacking techniques were used in the delivery of two strategic projects of the Water Corporation, nam ely the Perth Desalination - Water Supply Trun k Mains and the Perth Main Sewer Section 5 Stage 2. Although the p rojects are qu ite different in nature, they both employed p ipe jacking methods using closed-face, remotely controlled laserguided steerable tun nelli ng equipment, or to use the North American defi nition, microtunnelling (ASCE 36-0 l ). This paper describes how a cooperative app roach between the client, designer, const ructor and supplier can p rovide a technical so lution to mitigate serious project risks associated with pipeline construction in an urban environm en t.

Description of the Projects Perth desalination - water supply trunk mains project In mid-2004 the Western Australian Govern ment gave final app roval to proceed with a reverse osmosis seawater desalination plan t and associated infrastructure which would provide a rainfall-independent solutio n to the long running drought in Perth. The desalination suite of projects included the desalination p lant (located at Kwinana), a DN 1200 trunk main from the desalination plant to Thomso ns Reservoir in Beeliar, a DN1400 trunk mai n from Thomsons Reservoir to a new major pump station in Forrestdale and modifications at Thomsons Reservoir.

Maior road and rail crossings T he DN I 200 trunk main was I 0km long and the rou te traversed varied developed land including the major industrial area of Kwinana and included crossings of two major rail lines and a major highway. The DN 1400 trunk main was 12km long and included an important crossi ng of the

This paper was originally presented at the No Dig Down Under conference, Brisbane, December 2006.

10 8 FEBRUARY 2007

Water

Location

Ground Conditions

Design and Risk to be Mitigated

Kwinana Railway DN1200 MSCL 1 (two locations)

Wet sand Possible limestone pinnacles

• Sleeve mandatory for protecting railway in the event of main failure • Tolera nce on sleeve to permit subsequent installation of welded MSCL pipe • No interruption to roil traffic

Rockingham Road DN 1200MSCL

Dry sand Li mestone pinnacles

Kwinana Freeway and Mandurah Railway DN 1400 MSCL

Wet sand

• Lim it interruption to rood traffic • • • •

Sleeve under future railway N o interruption to freeway tra ffic No impact on freeway pavement running surface 120 metre drive under both freeway carriageways and ra ilway in median • Earthing of sleeve and product pipe in relation to the railway electric power system

Mitigating project risks for microtunnelling in a congested urban environment. main Kwinana Freeway where works were already underway for the construction of a major passenger rai l line in the Freeway median.

Thom sons Reservoir Storage at Thomsons Reservoir consists of a single concrete-lined pond of 93ML capacity constructed approximately 53 years ago as a local zone storage reservoir. However, with higher inf-lows from the Perth Desalination Plant, a larger inlet and ou tlet were required to increase the reservoir outflow capacity to deliver bulk water into the integrated water supply scheme as well as the local zone.

Perth Main Sewer The Perth Main Sewer included a major upgrade of a section of one of the original main sewers in Perch at Leederville, approximately 5 km from the city centre. The existing sewer was co nstructed in the I 930s using unlin ed rei nforced concrete pipes which had been sign ifican tly corroded by hydrogen sulphide attack. The section to

Journal of the Australian Water Association

be replaced included 865 metres of main sewer over which shops and buildings had been built. The works also included over 1000 metres of reticulation sewers in existing roadways.

Design and Project Specifications (the Designer's Perspective) Perth desalination projects - water supply trunk mains The design of the trunk mains was undertaken in traditional stages of p relimi nary design, engineering d esign and derailed design. Due to commitments to limit interruption to road and rail traffi c, four locations were identified where trenchless construction was considered necessary. Risk analysis identified different drivers and design issues at each location, which are summarised in Table I. All of the railway crossings required a sleeve to protect the railway embankment in the event of a failu re of the pressurised water main. Agreements were reached for tunnell ing under these crossings but tight constrain ts were imposed including fine tolerances on settlement and vibration. Due to the length of the Rockingh am Road crossing, and the nature of the rocky ground, it was considered that construction o f the water main inside a sleeve was justified in that this construction method would provide the lowest risk ro the


technical features

corrosion protection on the outside of the water main.

integrity of the 53 year old reservoir structure due to:

commuters and the local business area if open cue methods were to be used.

Hence the four crossi ngs were bundled into a single contract with a co mmon requirement to install a sleeve using microtunnelling and retrofit the welded MSCL water main inside the sleeve. This bundle was tendered as a des ign and construct package with specific design issues to be addressed in the tender. These included:

• Construction impact on the relatively chin concrete lining and jointing system; and

The al ignment of che sewer has a significant impact on road traffic, a busy high-speed bike path and adjoining mature trees. In addition, as the level of the sewer is below che water cable in free draining soil, open cue construction would require sign ificant well-poinc dewacering. Disposal of the groundwater presented an undesirable environmental impact and temporary lowering of the groundwater cable presented a high potential risk for structural damage to nearby structures.

• Sub mission of computations for loading stresses on che sleeve pipe due to jacking loads and surface loads; • To lerance on che constructed level of the sleeve pipe so that a minimum annulus around the water pipe was maintained, and assuming that the water main is a rigid pipe, i.e., che steel water ma in cannot be bent around bends in the product pipe due to construction tolerance; • Specified closed face, pressure-ba lanced machines to minimise settlement, or voids on the outside of the sleeve pipe. This was conside red necessary to minimise che risk of any settlement on voids threaten ing the operation of the railway, or the riding surface of che freeway pavements; • Minimise voids by limiti ng the size of the cutter head ro be not more that l O mm greater than the sleeve pipe diameter; lnsca llati on of threaded ports in every 4th precasc concrete sleeve pipe to allow lubrication and later grouting; • Detailed co nstruction planning co be su bmitted in advance co ensure well thought out procedures and conti ngency plans; • Sleeve pipe joints to be water tight co control any lubrication and grouti ng fluids from entering to the inside of the sleeve pipe; • T unnell ing machine to be steerable to control tolerances; • High electrical resistance of the sleeve to mitigate possible induced voltage differences berween the sleeve and the steel product pipe. The annulus berween the sleeve and the product pipes was grouted with low strength cementicious grout as it was considered that this provided a co nservative yet cost effective so lu tion to prevent possible corrosion of the inaccessible exterior of the produce pipe. Thomsons Reservoir

Thomsons Reservoir is a large concrete lined and roofed earth reservoir approx im ately 6 metres deep. Construction of a new ON 1400 outlet was identified as a significanc risk to the

• Inctoduccion of a possible leakage path along che outside of the pipeline. The reservoir co ncrete lining is highly sensitive to any form of soil displacement beneath the scrucrnre. In addition, crane access to the interior of che reservoir was limited due ro load limitations on che existing access ramps, and fou ndation limitations for large cranes with the capacity to reach over the top of the embankments. At che rime of rhe design of rhe reservoir outlet, it became evident that the equipment proposed by the successful tenderer for the desalination pipelines would also be suitable for the reservoir ou cler. Cose assessment of the options also showed that it was slightly cheaper. Previous use of chis method of construction at the Water Corporation 's Albany Sou ch Coast Reservoir Pond No. 2 in mid 2003 proved chat ch is was also a lower risk option. Accordingly, the reservoir ouclec was designed with chis equipment in mind. Effecti ve grouting of the exterior of th e sleeve pipe to seal it into the reservoir embankment was essential co prevent any possible leakage from che reservoir and as such threaded pores were specified in every pipe. T o maximise the usable volume in che reservoir, the new outlet pipe was requi red to exit the reservoir from a deep pie in the floor of th e reservoir. The outlet structure was designed to serve the dual purpose of receival shaft for the tunnelling machine and the permanent outlet structure for the reservoir. A rectangular caisson shaft was co nstructed to achieve chis. Perth Main Sewer

The Perch Main Sewer is at the end of its serviceable life, due mainly to hydrogen su lphide attack on rhe concrete pipes in che headspace of the sewer. le is being replaced in sections und er a program chat has been progressive over che last l Oyears or more. The extent of co rrosion and the high cost and disruption of bypass pumping makes relining of the old sewer impractical. le was planned that this particular sectio n would be replaced using conventional open cut and plastic lined reinforced concrete pipes. This planning work was done several years previously and ic became evident chat significant traffic growth in the meantime would result in major impacts to both

A review of the estimates taking into account current steel sheet piling costs revealed chat trenchless technology offered nor only a significantly reduced co nscrucrion impact, but also offered an approximate 25% cost saving.

Contractor Selection (the Client Perspective) Perth desalination projects - water supply trunk mains and Thomsons Reservoir

Contractor selection for the microtunnell ing co ntracts was preceded by a number of key project activities. Extensive risk assessment workshops were undertaken at key points in che projects from high level down to detailed eleme nts. GlS modell ing and multi -cri teria analysis together with extensive stakeholder consul cation was essential in pipeline route selection and provided the constraints chat fed into the risk assessment and contracti ng strategy. An assessment was also undertaken of market capability and constraints for rhe various contract options. Importantly, the ti me to establish and execute rhe contracts was carefully determined including contingency assessment to ensure the contracting strategy could del iver the assets in the right rime frame. Significant risks were identified during the risk assessment process including selection of the right co ntractors for tunnelling works. Any delays or errors wou ld delay the delivery of water by October 2006, putting at jeopardy hundreds of millions of dollars worth of associated works fo r the whole of the Perch Desali nation project. From the key project activities, a comprehensive contracting strategy was developed for the complete suite of integration projects including derails on che strategy for the microtunnelli ng contract. Critical to the microcunnelling co ntract was a frank assessment of client knowledge and expertise in tunnelling as well as a detailed assessment of industry capability and capacity, eq uipment availabili ty and

Journal of the Australian Water Association

Water

FEBRUARY 2007 109


technical features

personnel. The Water Corporation were fortunate to have two employees with extensive tun nelling experience in Europe, Southeast Asia, the east coast of Australia and previous projects in WA providi ng a wealth of knowledge in these areas. The microtunnelling strategy included a "Registration oflnterest" during the engineering design stage fo llowed by selective rendering from the p re-qualified renderers near the end of derailed design. This strategy ensu red high q ual ity contractors who could deliver on t ime whilst also providing a compet itive environment fo r prici ng. This resulted in minimisation of risk to costs and schedules. Tenders received were checked for co mpleteness and conformity including a "Tender Respo nse Schedule" against the following components:

SECONDARY SEAL ' MUCK RING' STEEL COLLAR

ELASTOMERIC SEAL

WATERSTOP

..___ _ _ _ _ _~ , ~ - - - - ~ A SPIGOT RECESS MDFPACKER

JOINT GROOVES CLOSED JOINT

SPIGOT DETAIL

Figure 1. J Series Jacking Pipe Joint.

Jacking Pipe Design and Manufacture (the Pipe Supplier's Perspective)

pressure of 500 kPa at I degree deflection, prior to the commencem en t of the Perch projects.

Jacking pipe design

• Sleeve pipe derails;

Precast concrete jacking pipes for both p rojects were designed and manufactured by Humes ar their concrete pipe facto ry in Welshpool, Perth, Western Australia. The pipes supplied were what the pipe supplier refers to as a J Series jacking pipe and these p rojects were the first signi ficant use this pipe.

• Grouting details;

Jacking pipe development

• Key contract personnel.

Until recenrly with in Australia, and earlier in other countries, rein forced concrete jacking pipe des igns have typically been based on a modification of pipes origin ally intended for installation in open trenches. In Australia this lead to the adoption of two different joint con fig uratio ns, the butt joint and in-wall (rubber ring) joint, which have typically been recom mended for culvert/ stormwarer and sewer/p ressure pipe app licatio ns respectively (CPM). The pipes have some limitatio ns which means chat they are often nor suited for use with modern microrunnelling equipment .

• Specific microrunnelling methodology; • Proposed design derails; • Installation methodologies; • Sire layout including derails of launch and retrieval pits; • Equipment details;

Tenders were then assessed using a weigh red points scoring system against the selection criteria of: • Microrun nelling design and methodology; • Capacity to undertake the contract (including equipment and expertise); • Key personnel; • D emonstrated ability to complete the contract in rhe timeframe; • Co st; and • Local policy considerations. Assessment of tenders showed that capacity was a major factor with many interested contractors unable ro deliver the p roject as thei r ru nnel boring machines were tied up in existing contracts either on the eastern seaboa rd of Austral ia or overseas. The contracting strategy proved very successful in contractor selection with assets delivered on rime, to a high standard and below budget.

Perth Main Sewer The Perth Main Sewer project went out to tender from a list of seven selected renderers and the tender analysis utilised a scoring system similar to the above bur with sl ightly di fferent criteria and weighti ngs. 110 FEBRUARY 2007

Water

I n 20 03, Humes began development of a steel collar jacking pipe that was compati ble with modern microtunnelling equipment. O ne of the key performance criteria identified early was the ability to retain the seal within a defl ected pipe joinr su bject to external hydrostatic pressure due to either groundwater or external lubrication fl uid. As part of the product development prototype designs were tested with external hydrostatic pressure applied to the joint. T esti ng led to the concl usion that the best joint profile included locating the seal in a deep recess on the pipe spigot leading to the adoptio n of the final joint derail sh own in Figure 1. Th is recess retai ns the seal inside the joint when subject to either internal or external hydrostatic pressure. ON I 800 pipe join ts were successfully tested at an external

Journal of the Australian Water Association

T he jacking pipes were d esigned in accordance with the sp ecifi cation and the contractor's installation requirements. T here is no Australian Standard for precast concrete jacking pipes in Australia, although some existing standards are relevan t to some aspects o f the jacking pipe design and manufacture. In general, the pipe design for both projects involved the fo llowing: • Selection of minimum pipe load class (AS 4058) to suit the permanent loads (earth , road and rail live loads) acting on each section of pipeline in accordance with AS 3725 and AS 4799 . • Maximum allowable jacking forces and associated joint deflections were calculated in accordance with published literature (CPM-1990); maximum values are listed in Table 2 . • E xternal cover to rein forceme nt was selected based on the groundwater analysis contained in the Specifications. Ocher durabil ity requirements for each proj ect are detailed below. • Four 20 mm internal diameter stain less steel threaded pores were cast into every fourth pipe which incl uded a thread ed plug on the inside and a simple non- return valve on the ou tside face. Fo r the Thomsons Reservoir drive, all pipes supplied in cluded these ports. For the Desalinatio n Plant pipelines jacking pipes were designed as sleeve pi pes. T he specification requ ired chat pi pe joints provide a "ti ght waterproof seal" and for all crossings the join t derail sh own in Figure I was sup plied. The flexible joint of the jackin g p ipe was only req u ired to have a lim ited life and as such mild


technical features

(a) Joint External Hydrostatic Testing

(b) PMS - Pipes in storage

(c) Installation of Interjack Pipes

Photograph 1. Jacking Pipe Testing, Storage and Installation . steel (uncoated) was selected as che pipe collar. For che Perch Main Sewer the jacki ng pipe was che product pipe and to meet the design life requirements fo r this project chermoplascic lining was cast into the inside surface and collars were manufactured from Grade 316 stainless steel. The internal li ning was a 1.5 mm thick plasticised PVC cast into the top 350 degrees of the pipe with a cover strip welded across each pipe joint. Intermediate jacking station pipes were designed in part based on the req uirements of an existing Japanese Specification (JSWAS-A2). The lead pipe (o r can) was mild steel (epoxy coated) designed to joint into che collar of a standard jacking pipe. The trail pipe was a modified precasc concrete pipe that was also lined with plastic. The internal diameter of the lead pipe was greater than the standard pipes allowing fo r the installation of wider plastic strip welded across the closed joint maintaining the continui ty of the plastic lining along the ful l length of the completed pipeline.

Pipe manufacture Details of pipes manufactu red for projects are contai ned in Table 2. Pipes were manufactured using the centrifugal spinn ing process which gives an off form finish on both ends (jacking faces) of the pipe and consistent concrete quality th roughout. Steel co llars were fabr icated to eight tolerances (Âą1 .5 mm on diameter) and then placed on a machi ned former in the mould which ensures the collar both held firmly in place and round during casting. The pipe spigot is fo rmed using a machined fo rmer fixed to che mould.

Construction of Jocked Pipelines (the Contractor's Perspective) The projects involved a total of eleven separate drives of both DN 1800 and DN1500 pipes as detailed in Table 3. The Perch Main Sewer project also involved the installation of 1000 m of reticulation sewers.

Pipe jacking equipment and personnel The DN1800 pipes were installed using a Herrenknecht AVN 1800 slu rry shield tunnelling machin e and the DN 1500 pipes were installed using a Herrenknechc AVN 1200 slurry shield machine with conversion kit. Cutti ng wheels for the drives ranged from soft, mixed and rock, dependent on the expected ground co nditions. W ith these machines, drilli ng fluids were pumped to the excavation face via slurry charge pipes and material excavated at the face passes th rough a cone crusher to the slurry discharge pipes. Slurry pumps were used to

transport the slurry (fluid/soil mixture) to settlement ranks at the surface where the solids were separated and the water was recycled back into the system. For the Perth Main Sewer project slurry pipelines were supported on specially designed frames chat resulted in zero damage to the plastic lining during both jacking and removal of slurry lines at the completion of jacking operations (see photograph 26). T he contractor employed only experienced crews on all stages of the microcunnell ing operations. In particular all tunnelling machi ne ope rators had installed many

Table 2. Jacking Pipe Details. Internal/ External Dia. (mml

Pipe Length (m)

Pipe Mass (t)

Pipe Jacking Capacity 1 (t)

2.32 2.32

4.85 6.72

000 I 430 1050 I 600

1500 / 1000 1000 / 21 50

1. Jacking forces (tonnes} listed included the maximum allowable values for straight and deflected /0.5 degrees} ioints.

Table 3. Summary of Drives for DN 1500 & DN 1800 Pipes. Line

Description

Pipe Dia. (mm)

No.

Line Length (m)

Caver to Na. of Duration/ Max Shift! top of lnterjack Jack Force (t)/ kPa 2 pipe (ml Stations

Perth Desalination Plant - Water Supply Trunk Mains & Thamsons Reservoir

#1 #2 #3 #4 #5

Rai l Crossing at Kwinana Rocking ham Road Crossing Rai l Crossing at Quarry Kwinana Freeway Crossing Thomsons Reservoir Inlet

1500 1500 1500 1800 1800

65 52 50 109 45

1800 1800 1800 1800 1800 1500

148 137 93 102 226 123

2.3 2 2 - 4.5 2-6 2 -8

0 0 0 0 0

8/S 11 / S 4/S 6/D 3/S

78 I 2.1 64 / 2.1 72 I 2.5 156 / 2.1 74/2.4

1 0 0 0

9/S 7 /S 5/S 4/S 6/D 7/S

167 / 1.6 146 / 1.5 116/1.8 158 /2.2 176/1.l 132/1.9

Perth Main Sewer Section 5 Stage 2

#6 #7 #8 #9 #10 #11

Ch.39 toACN 1814 AC Nl 814 to Nl815 AC N l 8 15 to Nl 8 l 6 AC N18 16 to N18 17 AC N181 7 to N18 18 Ch. 21.8 to 144.9

2.0 2.5 2.5 3.0 3.5 1.8 -

3.5 3.0 3.5 3.5 4.0 2.5

0

1. Durations stated are days of actual pipe ;acking only. S = single shift, D= double shift /24 hour operation} . 2. kPa figures listed= {maximum ;acking force} + {external surface area of the full length of ;acked pipeline}.

Journal of the Australian Water Association

Water

FEBRUARY 2007 111


technical features

trenchless technology

Photograph 2. Construction of Jacked Pipelines. ki lometres of pipe of chis diameter usi ng the same equipment in sim ilar soil conditions.

Shaft construction methods For the Perth Main Sewer project, 7m diameter reinforced concrete caissons were specified for the jacking and receival pits and these were designed and constructed by the co ntractor. Shafts were poured on site in nominal lifts of approximately 1.5 metres above ground, cured and then lowered by excavating mostly using a clamshell. A concrete plug cast at the base of the shaft provided both stabi lity and a watertight structure. Steel reinforcing was excluded from the shaft at pipe ex it and entry locations. A thrust block was cast on the back wall of the shaft to provide the necessary reaction ro the 850 tonne jacks. On the opposite wall an entrance seal, consisting of steel ring and single gasket, was bolted ro concrete case against the circular shaft, preventing the ingress of soil and water into the shaft as jacking pipes passed th rough the open ing. Steering and monitoring of line and level T he tunnelling mach ines used were laser guided and remotely controlled fro m a cabin at the surface. The specified tolerance on line and level for each of the projects were: • Desalination Plant Pipelines - tolerance on line only with "the maximum deviation from straight shall be l O mm over any 2.0 m length and 25 mm over any 12.0 m length of installed pipe". • Perch Main Sewer - as above and a "25 mm tolerance on vertical alignment" . All lines were installed within the specified tolerances with no backfall or low points on the very fla t grade (I in 2000) of the sewer lines. Lubrication, interjack stations and jacking forces Lu brication was used on all drives by injection of fluid into the exte rnal annulus

112 FEBRUARY 2007 Water

through the lubrication pores cast inro the pipes. Lubrication fluid consisted of a mixture of benronite and other additives co march the expected ground conditions. Jacking fo rces were carefully monitored by the operators and controlled by a combination of accurate steering, lubrication (manual system), shift times and the use of interjack stations. As can be seen in Table 2 jacking fo rces were maintained well below the jacking pipe capacity. Intermediate jacking stations were installed on two drives but were only used on rhe longer one (drive #I 0).

Post installation activities For the Perth Main Sewe r pipelines access chambers (manholes) were constructed withi n the caisson structures using a combi nation of precast concrete pipe and shaft sections and in situ concrete construction. Testing involved a visual inspection of the completed pipel ines and spark testing of the plastic lini ng. No leaking joints were detected our of almost 400 pipe joints within the 800 m length of main sewer installed. Conclusions The success of the two pipe jacking projects is attributed ro the following: • Carrying our derailed risk assessments at key stages in the projects; • Identifying and specifying project and design solutions chat mitigate the identified risks. The key risk mitigation measures included selection of appropriate pipe installation techniques, specification of minimum tunnelling machine and jacking pipe requirements an d requi red use of caissons fo r entry and exit shafts for the Perch Main Sewer; • A tendering process that ensured only appropriately experienced contractors with the correct equipment and personnel were selected; and • Close cooperation and interaction between the client, designer, pipe jacking

Journal of the Australian Water Association

contractor and pipe manufacturer during key stages of the project from design through co commissioning. The Perth Seawater Desalination Plant started producing potable water on 18 November 2006feeding into Perth's integrated system (!WSS). Full production is scheduled to be in place by April 2007.

The Authors Mark Oliver is a Senior Project Manager at the Water Corporation, email: mark.oliver@watercorporarion.com.au; Des Boland is rhe Manager of Water in WA region of GHD and was the technical di rector for the design; Malcolm McCormick is with DJ & MB McCormick, the contractors; John Bower is employed part rime as a Senior Design Engineer with Humes Technical (Design) Services in Brisbane and also a member of Standards Australia technical committee WS/6 Concrete Pipes, email: jbower@rinker.com.au References ASCE 36-0 I , Standard Construction Guidelines for Microtunneling, American Society of Civil Engineers, Rescon Virgin ia 20191-4400 Concrete Pipe Association of Australasia

(CPM), Concrete Pipe jacking Technical Brief, from hrrp://www.concpipe.asn.au Concrete Pipe Association of Australasia (CPAA1990), Jacking Design Guidelines Design Manual, from hrrp://www.concpipe.asn.au AS 3725-1989, Loads on buried concrete pipes, Standards Australia, NSW. AS 4058-1992, Precasr concrete pipes (pressure and non-pressure}, Standards Australia, NSW. AS 4799-2000, Installation of u11derground utility

services and pipelines within railway boundaries, Standards Australia, NSW. JSWAS-A2- 1991, Jacking Reinforced Concrete Pipes for Sewerage (Nominal Diameter 800 3000), Japan Sewage Works Agency. Tnfrastruccure Design Branch, DS60 Water Supply Distribution Standard, Version 3 August 2004, Water Corporation of Western Australia. Oliver M, M arch G (2006) Perch Seawater Desalination Project on Track. Water 33. 5 p68-69 .


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tee hn ica I features

IMPROVED DETECTABILITY OF UNDERGROUND INFRASTRUCTURE THE STAKEHOLDERS' PERSPECTIVE CD F Rogers, AM Thomas, N Metje, D N Chapman Abstract W h ile trenchless installation of utility infrastructure provides majo r im provement ove r trenches in terms of engineeri ng sustainability (addressing particularly the social an d environmental pillars in the 'th ree pi llar' model), lack of detectabili ty of existing bu ried utility infrasrructure, by geophysical survey, can compromise the benefits if local excavation is needed to estab lish exact locations. More importantly, lack of complete knowledge o n the location of existing uti lity in frastructure increases safety risks fo r personnel engaged in b uried utility work. Location of buried utilities can be undertaken using a number of geophysical m ethods, but all are influenced in their effi cacy and accuracy by the prevailing ground conditions and milicy type. Success rates in location have fa llen well short of the necessary 100 % when used without recourse to local 'p roving' excavations. T o ensure chat stakeholder requirements are incorporated into a major new UK study, entitled Mapping the Underworld (MTU), a questionnaire has been used to determine current and furu re accuracy requirements. T he resulting data are faci litating assessment of geophysical location options against stakeholder needs, and prnvidi ng a greater understanding of the bounds within which these requirements are achievable with current detection methods. T his paper introduces MTU, outl ines how MTU is assessing key location difficulties and relates them to questionnaire findi ngs to establish future challenges to be met by geophysical survey methods. It concludes that full understanding of geophysical soil and utility characteristics is essential if detection of buried utilities is to meet stakeholder accuracy and detectability

This paper was presented by Professor Rogers at the No Dig Down Under conference, Brisbane, Dec 2006. Professor Rogers was rhe 2006 recipient of the Internacional Society of Trenchless Technology Award for lnrernacional Excellence in Research.

114 FEBRUARY 2007 Water

Drainage services

Other

Infrastructure design

4%

4%

Government (local and national)

6%

25%

Consultant 7%

Contractor Utility survey 12%

22%

Utility provider 14%

Figure 1. Respond ents by ind ustry sector. requirements, and recommends how this may be achieved practically.

Introduction In the UK alone, there are an estimated eight mill ion miles of p ipes and cables forming the u nderground service in frastructure. U nforcun ately, location records are often incomplete or inaccurate, leading to significant difficulties in planning works that may impact on utilities. It was against this backdrop that MTU was formed as a m ulti-disciplinary research project, combining expertise from a number of UK universities. As well as actively investigating the developm ent of a multi-sensor device for utility location (e.g. low frequency electro magnetics, acoustic wave, ground penetrating radar and asset tagging) and mappi ng, the p roject coordinators also actively seek industrial partners to maximise their effectiveness (for more detailed information about MTU, see Rogers et al, 2006 and http://wvvw.mapp ingtheunderworld.ac. uk).

As it can be argued chat the utility location problem is socially constructed , d ue to the requirements of society for a utility infrastructure adequate for its growing

Journal of the Australian Water Association

Finding the accuracy targets for a major UK development of multisensory techniques. needs, the MTU project has actively sought the views of stakeholders as a means of fo rmulating socially acceptable solutions. To chis end, a quest ion naire was p repared at the end of 2005, which requested information of stakeholders on the depth ranges within which they require geophysical utility location to operate, together with their requirements for accuracy of location in plan and depth . T he q uestionnaire also allowed stakeholders the opportunity to provide comments o n geophysical utility locatio n, an opportunity which was taken up by many respondents, who together provided much usefu l data. A wide range of stakeholders was asked to complete the questio nnaire, wh ich has provided an initial sample base of 70 responses received up to the 2nd August 2006, the details o f which are recorded in chis paper. Following the success of the in itial sample, it is hoped ch at the question naire will continue to provide an


technical features

increasingly valuable record of rhe needs of srakeholders.

Demographics

Over 60

Under 20 1%

20 to 30

20%

increasing distance from the transmitter (see Thomas et aL, 2006a). Also, rhe srrengrh of transmitted signals is ofren limited by legislation ro red uce in rerference ro ocher devices. T hese two facrors limit the maximum depth within which a particular location technology will be able ro detect uti lities. For this reaso n, MTU required an understanding of the depth ranges within wh ich stakeholders require location equipment ro operate.

As can be seen from Figure l, 30 to 40 respo nses were received from a wide 14% variery of utility location sectors, thereby covering the major stakeholder groups chat have an interest in the MTU project. The 50 to 60 significant size of four groups 31 % 40 to 50 (government, contractors, uriliry 27% providers and utility su rvey) ensures chat the largesr sectors responsible for Stakeholders were asked to provide Figure 2. Respond ents by age range. screetworks and uriliry maintenance derails of the mi nimum an d are properly represenred. The rhree maxim um depths of interest ro them data). This validates rwo central features of responses included wirh in 'ocher' were a for 'normal' and ' rarer' scenarios. The rhe MTU project - the development of trade association, a consulrant and an resu lts, for depths less than 5m, are depicted more sophisricared locarion equipment, equipment manufacturer. in Figure 4, which illustrates that rhe coupled wi th research inro the dynamic As shown in Figure 2, the age range of definition of a 'normal' depth is anywhere response of soils ro geophysical signals, a respondents is dominated by stakeholders between surface level and 3m deep, wirh lack of understanding of rhe latter being over rhe age of forty, with less than I 0% ' rarer' deprhs being generally below 4.5m. porenrially rhe grearesr source of error. describi ng rhemselves as under 40. Ir could, T he absence of significant inreresr in depths therefore, be argued chat the questionnaire data may be slightly biased by the different arci rudes of older stakeholders relative to those of younger generations. However, ir may simply be ch ar it reflects the engineering industry's difficulry in recruiring younger personnel.

Importance of Specific Issues In order to confirm the va lidity of the research inro the geophysical location of ucilicies, respo ndents were req uested ro rare fo ur questions on a scale of'cricical', imporcanr', 'not important', and 'no opi nion'. The fo ur questions related to the importance of accurate determi nation of uti li ty depth, accurare derecrion of uril iries, accurare derecrion and depth esrimation for critical utilities (defi ned as those that pose significant health and safety problems if damaged) and understanding pocencial errors. The resul rs of rhese questions shown in Figure 3 indicare rhat all fou r issues are of great importance to stakeholders. Of highest priority to stakeholders is rhe need to accurately locate utilities that pose significant health and safery issues, which highlights the importance of utiliry location as a form of risk minimisation and the importance of rhe MTU projecr as a means of improving healrh and safety of construction. Of slightly lower importance, from the stakeholder perspecrive, are accurare derecrion and understan ding porencial errors. That these two factors are shown ro be of equal imporrance is significant in char both affect rhe confidence of stakeholders in location equipmenc (i.e. errors in derecrion, and rhe level of accuracy obtained, bod, degrade the usefulness of location survey

Although all four issues were considered highly important, rhe issue of accurate deprh assessment was given lowest priority by stakeholders, porentially because once plan location has been esrablished wirh in an acceptable rolerance, hand d igging is ofren undertaken when excavarion approaches rhe expected uriliry depth . However, ir can be seen later in this paper chat stakeholders are also slighrly more resrricrive in their accuracy requiremenrs for depth rhan plan location. The reason for this minor discrepa ncy is unclear from rhe questionnaire data, bur it could be speculated char accurate depth assessment is of limited use ro srakeholders if the plan locarion is not also known within acceptable accuracy limits, while plan locarion alone is still of use even wirhour depth info rmarion.

Depth Requirements All geophysical survey signals suffer from attenuation, char is they lose energy wirh

Accurate depth assessment

Accurate detection

between 3m and 4.5m can be speculated to be due ro there being fewer utilities installed wirhin this depth range, in comparison to the upper 3m where a wide range of pipes and cables are ofren insralled (due ro the obvious cosr advantages associated with reduced trench excavation deprh ). From Figure 4 it can be seen rhat almost I 0% of normal, and approximately 45% of rarer, scenarios involve location of uril iries grearer than 5m deep. The questionnaire results for all maximum deprh requ iremenrs deeper than 5m are shown in Figure 5. While only five respondents requ ired normal maximu m deprhs greater than 5m, rhose requirements extended ro a depth of 40111. For rarer maxim um deprhs it can be seen rhar a significanr number of respo ndenrs are inreresred in uriliry location no deeper than 20111. T wo respondenrs (not shown in Figure 5 fo r scaling purposes) had deprh requirements, for rarer survey scenarios, of 150m and 250m, th e larter

Locating cntical services Understanding potential errors

1 No opinion DNot important o Important o Critical

Figure 3. Responses to questions on the importance of specific issues. Journal of the Australian Water Association Water FEBRUARY 2007 115


technical features

..

representing the maximum depth requirement over all responses. From Figures 4 and 5, it can be seen that stakeholders require utiliry location equipmen t to operate over a very wide depth range. I t can also be seen that the difference between normal and rarer scenarios, in terms of maximum depth , is not entirely clear, with rarer maximum depths for some stakeholders being normal maximum d epths for others. Also, the total depth range requ ired is between surface level and 250m deep, which provides a sign ificant challenge to any proj ect, such as MTU, seeking to fulfil all stakeholder requirements. However, as an initial goal, it can be deduced from the graphs that technology able to detect all utilities between surface level and 20 m deep will provide a useful fu nction to the large majority of stakeholders.

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The accuracy requirements gained from the question naire responses are ill ustrated in Figure 6, which shows the average requirement, for both horizon tal and vertical accuracy, for all service types investigated. A significant feature of chis figure is the lack of a marked differentiation berween the requirem ents for horizontal and vertical accuracy, with the most obvious differentiation b eing a slightly higher accuracy requirement vertically for requirements under I 00mm, together with slightly higher horizontal requirements for accuracies between 100mm and 300mm. T his ind icates chat, fo r general purposes, any technology u nable to provide accuracy better than 300mm is inappropriate for most utility location needs and chat

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Figure 4. Depths of interest to stakeholders (< 5m depth) . 80 70

The accuracy o f geophysical utility location can vary within significant limi ts d ue to the effect soil has on su rvey signals and the contrast between so il and utilities that determine the strength o f reflect ion char will occur (see T homas et al, 20066) . Therefore, it is no t su rprising that imp roving the accuracy of utility location is a central aspect of the MTU project as, without acceptab le and repeatable tolerances, confidence in location technologies will be low. Hence, the question naire sought data on the accuracy requirem ents of stakehold ers for both depth and plan location assessmen t. H owever, seeki ng a single accuracy requirement would hide the variations in stakeholder perspectives that can be expected to accompany the safety and cost implications of unexpectedly encountering such utilities as high voltage electricity cables. Thus the questionnaire investigated the accuracy requirements fo r a wide range of utility types and sizes.

FEBRUARY 2007

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Accuracy Requirements

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o.. 10 5 0 >0rrm & >50mm & >100mm >150mm >200mm >250mm >300rrm >350rrm >400mm >450mm >SOOmm <=SOrrm <=100mm & & & & & & & & <=150mm <=200rrm <=250rrm <=300rrm <=350mm <=400mm <=450mm <=SOOmn

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Figure 6. Average accuracy requirements for all utilities. equipment should be able co provide accuracy much better than I 00mm if ic desires wide market acceptance (and preferably better than 50mm). While one of the goals o f the MTU project is to optimise accuracy, it sho uld b e noted that a sig nificant subset of the responses (over 10%) are much less

Journal of the Australian Water Association

restrictive in their n eeds, req uiring accuracies of 450mm or more, both horizontally and vertically. A more derailed view of the responses is provided in Figures 7 and 8, wh ich show variations in accuracy req uirements over the full range of ut ility types and sizes, for horizontal and vertical accuracy respectively.


technical features

In terms of horizontal accuracy requirements, the applicability of I 00mm and 300mm accuracy bands is evident across a wide range of utilities. However, several other interesting fearnres are evident from Figure 7, the most significant being that most respondents require a higher degree of accuracy fo r communications and high voltage electricity services, in comparison to other service types. Also, there is a great deal of variation in accuracy between different service types (presumably due to safety and cost concerns), fo r chose respondents with requirements greater than I 00mm. In comparison to Figure 7, the verrical accuracy requirements of Figure 8 show two significant feaw res. Firstly, che requirements are clearly focussed on two accuracy bands, the first being up to I 00mm, as mencioned above, but with the majority of responses requ iri ng an omside accuracy of less than 200mm, which is slightly more restrictive than the requirements for horizo ntal accuracy. Secondly, the requirements are more uniform over th e whole range of utility types and sizes, with only slightly greater accuracy requirements for small gas, small water, electricity cables and communications cables.

>500mm >4 50mm & <=500mm >400mm & <=450mm >350mm & <=400mm >300mm & <=350mm

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Figure 7. Hori zo ntal accuracy requirements (percentages per discrete 50mm increment). >500mm >450mm & <• 500mm >400mm & <• 450mm >350mm & <• 400mm >300mm & <= 350mm >250mm & <=300mm >200mm & <= 250mm >150mm & <=200mm >100mm & <• 150mm >50mm & <z 100mm

Comments While the questions described above were considered che most important fo r inclusion in the MTU questionnaire, it was also appropriate to allow respondents to include any comments they considered appropriate to utility locatio n. A large number of stakeholders (39 ou t of 70) took chis opportunity to provide their perspective, and their comments have been class ified into the co mmon groups depicted in Figure 9. A few comments have been specifically included below to represent some areas of importance to stakeholders, although it should be noted chat all were considered of value. The first of these represents concern over the usefu lness of current location equipment (illustrati ng the reason why the MTU project exists), and was from a respondent who wrote ' First hand experience of grou nd radar has shown it to be either very useful or totally useless, a middle ground needs to be reached'. Another respondent wrote 'I am concerned re the use of plastic pipes fo r services such as gas and water nowadays which are generally more difficult to detect', illustrating one of the difficulties current location techniques have to address if location accuracy is to imp rove. The accuracy of utility maps is also of concern, with one comment suggesting that

Percentages: • 0-10 11 10-20 IJ 20-30 IJ 30-40 CJ 40-50

Figure 8. Vertica l accuracy requi rements (percentages per disc rete 50mm i ncrement) . Societal impact

Cost and time Issues 6%

of poo;!;cation

Accuracy and - - -detection issues

&~1 /

\ Other comments -

6% Health and ~ safety 10"'"•'

28%

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% / Need for accurate utility maps 12%

,-----Communication . . "'_ - - - - - - and training Limciti:;~~; of issues 22% equipment 14%

Figure 9. Classification of stakeholder co mments. 'Current utili ty records are not reliable to any degree'. The reason for chis co ncern was highlighted by another respondent who co mmenced chat 'A clear, comprehensive

and accurate map of the services would help to reduce the level of uncertainty associated with sub-surface wo rkings and therefore help the development industry in

Journal of the Australian Water Association

Water

FEBRUARY 2007 1 17


technical features

bringing forward new projects', which illustrates the impact that improved utility location (which is also a feature of the MTU research) will have on reducing problems and costs for the development sector. l n term s of the accuracy that geophysical ut ility mapping can provide, it is interesting to note that o ne respondent commented 'There are many types of utility detection equipment available in the market. No information is available about their perform ance accuracy', which is an important topic consi dered in the next section. The importance of this performance accuracy, in terms of safety, was highlighted in che comment ' ... understanding the operational limitations on any detection equipment and the fi nd ings are critical to safety.' The importance of h ealth and safety to stakeholders was further highlighted by the comment' ... what concerns m e first is the risk to the operator/worker, secondly the cost of repair and lastly the inconvenience co the utility com pany' and the inappropriateness of relying entirely on accurate locatio n techniques, at the expense of safe working practices, was further highligh ted by a comment chat 'Accurate detection and positioning would be a very useful planning tool b ut would never be used as a substitute for safe digging practice.' A further two comments illustrated the fact that even t he most accurate detection can fail if the resulting d ata are not communicated effectively. W hi le che first comment stated that what the MTU project needs to con cen trate on is ' ... accurate devices that can be used in the field to assist the hole digger find buried assets', the second comm ent warned that 'It is not only important to obtain the correct information with regards to location and depth of utilities, but to present that information in a clear and user friend ly format. ' Finally, one respondent commented that 'Accuracy requirements are job specifi c and if a mapping contractor cannot provide the accuracy I need there is no poi nt in using him', highlighting the importance of the MTU project in improving utiliry location accuracy.

Future Work A significant feature of the comments was the need for clear and user friendly information. This indicates chat there is potential for use of the q uestionnaire data as a means by which u tility location equipment can b e judged in stakeholder acceptable term s - the extent to which the equipment meets their own expectations. This is possible by comparing the accuracy

118 FEBRUARY 2007 Water

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Figure l 0. Example accuracy assessment distributions. of location, for a wide range of real world scenarios at a proposed UK test facility, to the distribution o f questionnaire data for the type and size of utility being located. Examples of such distribut ions are ill ustrated in F igure I 0 , based on questionnaire responses to date. It can be seen that the distribution can be used to provide an estimate of the percentage of stakeholders who would be satisfied by the ach ieved location accuracy - providing an easily understood ind icator of equipment performance. Furthermore, the distributions provide an opportunity to assess other important facto rs, such as the adequacy of urility maps and systems for the pred iction of soil, and other material, properties. However, an op portunity that should not be ignored is the possibility of using stakeholder led location assessment techniques as a tool for the assessment of risk to site operatives due to individual location methods.

Conclusions Withou t kn owing the requirements of stakeholders, any project intended to improve geophysical utility location risks imposing arbitrary tolerances that may be wholly inapprop riate co end users and also cannot assess the efficacy of equipment and techniques without being highly subj ective. Through use of the questionnaire, the MTU project has avoided such pitfalls and gained data chat can be used to form ulate stakeholder constructed assessment systems for classifying complex soil responses to signals, as well as for use in assessing the performance of utility location equipm ent, techniques and utility provider record maps. The importance of the MTU app roach, in attempting to use stakeholder perspectives for su ch diverse assessment system s, should not be underestimated. Without such an approach, MTU would be forced to adop t a system based on the concept chat twice as

Journal of the Australian Water Association

accurate is twice as good. However, it is obvious from Figure 10 chat the accuracy to acceptability relationship is far from linear and varies between utility type and size. The MTU approach therefore has the advantage that it provides an opportunity to classify equipment and methods in terms of the utilities they are most effective at locating. One of the most significant outcomes of the questionnaire is that the needs of stakeholders are diverse and cannot be simplified to a single depth requirem ent or level of accuracy, from which it can be seen chat use of mul ti-sensor techniques (e.g. low frequency electromagnetics, acoustics, ground penetrating radar and asset ragging), as proposed by the MTU project, is req uired if these diverse needs are to be respected. T h is is particularly impo rtant as d eeper depth requirements generally cause a need for lower signal frequencies, which reduce the survey resolution and so place a limit on the smallest detectable util ity. T herefore, use of complementary sensors that extend the detection range over that of single technology equipment, for all soil conditions, is an important MTU goal. A further significant outcome is the identification of the level of accuracy required by stakeholders in utility location (preferably better than 100mm and definitely no worse than 300mm). The ability of equip ment to work within such tight tolerances is directly proportional to the impact soil has on the signals being transmitted and received. Furtherm ore, whether a utility will be detected al all , for reflective survey systems such as radar, will depend on the contrast between the utility and adjacent soils. Meeting the accuracy and detectability needs highlighted by the questionnaire therefore requires a full understand ing of both soil and utility material geophysical p roperties. In order chat its own research outcomes can provide the necessary accuracy, a fundamenta l aspect of the MTU project is


technical features

the testing and mapping of soil geophysical properties, as without an understanding of this stakeholder needs cannot be consistently met or exceeded. To this end, when a full understandi ng of the interrelationships between geotechnical and geophysical soil properties has been achieved, MTU intends to translate these data into geographical maps that allow more effective interpretation of utility surveys, thus providing increased accuracy for stakeholders. In terms of the comments received, it is important to note that research into utility location is incomplete without inclusio n of the issues they raise. The most important issue, from stakeholder comments, appears to be the difficulty in obtaining consistently good accuracy levels (including comments on the limitations of current equipment and mapping) and there is concern that some utility materials are installed without there being a clear strategy fo r their later detection. Furthermore, the link between accurate detection and health and safety was com mented on by many respondents and illustrates that the issue of utility location is not just an issue of accurate record keeping, but rather is also largely an issue of ensuring the safety of personnel. However, a very significant number of comments were concerned with communication and training issues, including concerns that there is not enough information on performance and limitations of current detection equipment (which was also high lighted as a potential safety risk in itself). Ir may therefore be concluded that the proposed MTU test facility, together with assessment systems derailed in this paper, may go some way toward addressing chis issue. To conclude, as one respondent commented, "There is a vast wealth of experience and knowledge in the industry which can be ' made to good use' by the research teams. It is important that this is taken to full advantage". It is hoped that the initial questionnaire survey has respected this ideal by actively seeking input from stakeholders. However, the degree to which this will be achieved over the lifetime of the MTU project is dependent on the extent to which industry is able to share its experience and knowledge. Readers of this paper are therefore encouraged to include their perspective by completing the questionnaire online at http:/ /www.mappingtheunderworld. ac. uk/ q uesrion naire. html.

Acknowledgments The authors gracefully acknowledge the financial and other support provided by the

The Location Project - Extracted from Rogers et al (2006) The problems associated with inaccurate location of buried pipes and cables have been very serious for many years and are getting worse as a result of increasing traffic congestion in the UK's major urban areas. It is against this backdrop that a £ 1 .2m four year project, entitled Mapping the Underworld (MTU), funded both by EPSRC and UK Water Industry Research, commenced in July 2005. The aim of the MTU project is to locate, map and share information on buried utilities. The research and results presented within this paper are part of the Location Project, which is one of the four core MTU research projects (see www.mappingtheunderworld .ac. uk). The overall aim of the Location Project is to investigate the feasibility of several novel approaches, alongside greatly enhanced existing approaches, to be combined in a si ngle multi-modal approach to the location, and ideally identification a nd condition assessment of buried assets, whether deployed from the surface or sub-surface from within an existing utility conduit. The objectives of the research are:

• To determine the capabilities of existing technologies and the potential of novel technologies for location and identification of buried utilities under the three broad headings of GPR, acoustics and quasi-static fields. • To explore in detail the most promising technologies for integration into a single multi-utility device.

• To produce a fundamental understanding of the limitations of signal propagation through and reflection from the underground media encountered in the above operations (i.e. bound and unbound pavement structures, soils and fill materials, pipes and their contents).

• To explore the feasibil ity of combining the techniques to create an integrated, multi-sensor device. • To explore the feasibility of deployment of the multi-sensor device both from the surface and from a pig (pipeline inspection gauge) that travels through an existing buried conduit. • To conduct initial proof of concept trials and, as a result, establish proposals for a comprehensive research programme for development and proof testing of a fully-operational prototype system. The aims and objectives are to be met by the combined work of six research groups drown from four UK universities (the Universities of Birmingham, Southampton, Bath and Sheffield) and covering civil engineering (2 groups), electrical and electronic engineering (3 groups) and sound and vibration studies (1 group) .

UK's Engineering and Physical Science Research Council (EPSRC) and UK Water Industry Research (UKWlR). The authors also express gratitude to John Castle, of the Internacional Society for Trenchless T echnology, for his valued assistance in publicising the questionnaire. Finally, this paper is dedicated to the industry stakeholders who gave their time to respond to the questionnaire, as without their involvement this research work could not have been produced.

The Authors Professor Chris Rogers, email C.D.F.Rogers@bham.ac.uk, Andrew Thomas, Dr Nicole Metje and Dr David Chapman are all with the Department of Civil Engineeri ng, University of Birmingham, Edgbaston, Birmingham, United Kingdom. The dates and locations

of future workshops can be accessed on www.mappingtheunderworld.ac.uk.

References Rogers, C.D. F. , Chapman, 0.N. and Metje, N. (2006 ) "Mapping the Underworld - UK Utilities M apping", Proc. of 11th Int. Conf. on Ground Probing Radar (G PR2006) , Columbus, Ohio, USA, 19-22 June (CDROM). Thomas, A.M., Metje, N ., Rogers, C.D.F. and C hapman, 0 . (2006a) "Ground Penetrating Radar Interpretation as a Function of Soil Response Complexity in Utility Mapping" I l th International Confe rence on Ground Penetrating Radar, June 19-22, Col umbus Ohio, USA (CDROM). Thomas, A.M., Lim, H.M., Metje, N., Rogers, C.O .F., Chap man, O .N. and Atkins, P.R. (2006b) "The Complexiry of GPR Data Interpretation in Railway Foundation Surveys", RailFound 06, lst International Conference on Railway Foundations, Birmingham, UK, 11th-13th September.

The Questionnaire Readers can support the project and provide valuable information by filling in the questionnaire at http://www.mappingtheunderworld.oc.uk/questionnoire.html. Regular updates on the questionnaire con also be found on http://www.moppingtheunderworld. oc.uk. It would be extremely beneficial to gain information from as wide a cross-section of the international community as possible, and thus we would welcome views from Australia. The website also hos details of Mapping the Underworld workshops, which provide the chance for stakeholders to express their opinions and direct the research according to the industry's research needs. Views from across the world are equally very welcome at the workshops.

Journal of the Australian Water Association

Water

FEBRUARY 2007 119


t0rhnical features

TRIALS OF THE CORROSION INHIBITOR, SULFALOCK HIGELTM S Barclay, S Jessop, S LeCount, D McMinn, K Johns Abstract Trials have been performed to assess che effectiveness of Orica's specially formulated liquid magnesium hydroxide produce, SulfaLock Hi Gel™ in inhibiting corrosion of concrete sewers and associated structures withi n Syd ney Water's sewers. This paper derails the work perfo rmed and che results obtained over a three-year evaluation period on 250 m of the Sans Souci Carrier, and on 4.2 km of work performed on sections of the Northern Georges River Sub-main .

Introduction Sydney Water Corporation provides wastewater services to com munities across rh e Sydney, Blue Mountains and Illawa rra regions. Similar to many Australian Water Authorities, sections of the sewerage system experience aggressive acid corrosion char without intervention will result in a sign ificant reduction of the designed asset life and dramatically increase the fund ing requirements fo r structural renewal as opposed to non-structu ral refurbishment. The cost of replacing a relatively shore length of sewer main can very quickly stretch into the millions. The Sans Souci Carrier was internally in spected in May 2000 and found co have aggressive gas attack of the concrete sections and structures. T he Maintenance Holes (M H) in Kogarah Bay were showing evidence of tidal sal twater ingress and surcharging during heavy rain events. The sewer changes shape from box section to round section between MH B and MH C approximately 50 m upstream of the Pumping Station co llecting maintenance hole. The access to che site was favo urable being in a golf course with no immediate residential custo mers being affected by the sewer equipment required to undertake the trial. These factors all contributed co rhe ideal sewer to trial rhe Sul faLock HiGel™ produce and develop a reliable application method using standard sewer mai ntenance technologies. The Northern Georges River Sub-main is a major sewerage system char conveys This paper was originally presented at the NoDig Con fe rence, Brisbane, October 2006.

120 FEBRUARY 2007 Water

wastewater flows from approximately 25 0,000 residents from rhe upper Georges River areas co the Malabar Sewerage T reatment Plant. Sydney Water conducted traverse inspectio ns in 2004 which revealed that internal concrete surfaces had undergone significant deterioration and represented a high risk of collapse as reinforceme nt was exposed and corroding in several sections due to gas arrack. Following che successful sans souci trial, Sul faLock HiGel™ was chosen as an interim measure co protect a coral of 4.2 km of che NGRS from further arrack until the exposed sections could be rehabilitated. HiGel™ was selected as it co uld be applied quickly and relatively cost effectively, and without the need co di vert sewage flows.

H owever the net effect of these two variables may be most simply characterised by che surface pH. T he rate of concrete corrosion is expressed in Figure I. Ar a wall pH of 3, the corrosion rare will be in the order of 2.5 mm/year.

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25

Figure 1. The effect of wall pH on the

Spraying thixotropic magnesium hydroxide HiGel onto corroding concrete gives at least , . two years protection. Mechanism of Sulphide Generation and Acid Production The most common form of sewerage asset corrosion is acid arrack. This process as observed in concrete sewers is a two-step process; che reduction of sulphates co sulphides in the anaerobic sewage and che ox idisation of released H 2S co sulphuric acid by sulphur oxidising bacteria on the exposed concrete surfaces. (Hydrogen Sulphide Manual, 1989, Vol. I) The ingress of seawater increases rhe sulphate co ncencracion within sewage thus increasing the potential fo r release of H 2S from the sewage. Sulphuric acid reacts with che calci um hydroxide present in concrete co form calcium sulphate as a corrosion product. Calcium sulphate is a soft, porous compound with no binding or structural propemes. The corrosion rate of concrete pipes is usually dependent on three main criteria; the fl ux of H 2S(g) co the pipe wall, rhe race of sulphuric acid production, che alkalinity of the pipe material (Meyer, 1980) .

Journal of the Australian Water Association

rate of corros ion.

Typically a sewer pipe is conside red co be near the end of its useable life span once the co ncrete covering the reinforc ing reaches less than one third of its original th ickness (Pomeroy, I 974).

Orica's Sulfa Lock HiGel™ Corrosion Protection Mechanism SulfaLock HiGel™ is a low viscosity, highly concentrated aqueous suspension of magnesium hydroxide char is formu lated co be chixorropic. T hus it is easily pumped like ocher co mmon liquids, while upon application it secs co a gel which strongly adh eres co a surface. Typically, a coating of approximately 2 mm thickness can be achieved in a si ngle pass. Another important benefit of Sulfa Lock HiGel™ is char magnesium hydroxide is class ified as a non-hazardous, nondangerous good. This is particularly important in rhe application process where alternative technologies would require specialised personal protective equipment and training co guard against occupational exposure to toxic or harmful chemicals. The spray application of SulfaLock Hi Gel™ onto che sewer wall neutralises acid already present and provides an enduring alkaline surface coating. In additi on, the high wall pH is thought co retard che proliferation of acid formi ng bacteria, The SulfaLock HiGel™ technology achieves corrosion protection


technical features

irrespective of the gaseous H 2S concentration, changes in wastewater temperature, pH, flow and composition.

~

~ ... ~

...

Figure 2. Moni tori ng locations along the Sans Souci Carrier.

Li /

........_,__,., ~.:r...;' - - -""""- - - .

Before Orica could apply the SulfaLock HiGel™ , che section of sewer chosen for the trial, consisti ng of the I 066 mm x I 066 mm box and circular sections and the 3 sewer maintenance holes A, B and C, had to be cleaned ro remove the slime layer and loosely b onded corrosion products. This was ach ieved by water clean ing using a medium p ressu re sewer-cleani ng jeerer ed ucror rig. Altho ugh high-p ressure water was available it was nor used since only che loose particles had to be removed.

Sample point No 4 UIS of MH (Treated)

::---- . .: : : : ~ ~ =-~ ~~

Sample point No 8 In MH (Untreated)

Figure 3. Sans Souci Carrier Schematic. Sulfalock HiGel™ application T he equipment used to apply che produce o nro che sewer walls was a specially designed spray boar (Figure 5) that was towed along che sewer whilst continuously pumping SulfaLock Hi Gel™. T he spray boar featu red six spray nozzles that allowed for fu ll coverage of 200 degrees o f sewer crown. Application onto the maintenance hole surface was achieved using a pressurised h and-held extendab le spray lance, similar ro airless spray painting (Figure 6).

Figure 6. Manhole Application. Monitoring sewer wall pH

Spray Boat.

Sample point No 3 in MH (Treated)

M H Buried (Not tested)

Figure 4. Manhole after Water C leaning.

Figure 5. O rica Sulfalock HiGel™

4

1b

Surface preparation

Cleaning con firmed that the carrier had experienced significant corrosion as material was fo u nd to fall away easily fro m the sewer walls, an d the exposed clean concrete and aggregate was characterised by its surface roughness. Once cleaned, the carrier was reexamined using CCTV to ensure char there was adequate removal of the co rroded concrete with a solid base for application of the SulfaLock H iGel™ . Figure 4 shows a manhole after cleaning.

6 5

~ ~ ) 4 -----1

Sans Souci Pilot Trial The trial consisted of th ree distinct stages including surface p reparation, SulfaLock HiGel™ application and pH monitoring of the sewer walls. Prior to the surface preparation the sewer was inspected using CCTV and the concrete surfaces were characterised to determine the baseline pH for comparison during the trial. A schematic d iagram and simple process flow d iagram of the Sans Souci Carrier is shown in Figures 2 and 3 .

3

1a

The performance of the coating was measured in terms of its ability to maintain a wall pH of neutral or higher. This was evaluated over a twelve month period by taking samples of che sewer an d

maintenance hole surfaces at various points and testing the pH. (Refer to Figures 2 an d 3 for the location of these test points.) Samples were taken immediately prior to che trial and then collected q uarterly over the duration of the 12-month mon itoring period. Further rests were conducted d uring che ensui ng 2 years

pH testing Tab le 1 and Figure 7 show that the sp ray application o f SulfaLock H iGel™ coating increased and mai ntained the pH of che sewer wall from an average of pH 3 .65 before application to an average of pH 9.25 for all treated areas immediately post application. The fluctuation in pH values measured at rest points can be attributed to the difficulty of sample collection where a layer ofHiGel™/concrece is ch ipped off the sewer wall. For example che pH at location 8 (untreated con trol area) was observed to fluctuate between pH 2.9 and pH 3.9. However, given che intentio n was ro determine whether the sewer wall p H was acid ic, alkaline or basic, the observed fluctuations did nor affect che effectiveness of che rest method used. Ac the 9-month resti ng period a special sample was caken from the crown of the sewer downstream of manhole B. T his sample was taken horizontally alo ng the

Journal of the Australian Water Association

water

FEBRUARY 2007 121


technical features

Table l. p H Test Results . Test Point Description

#

Treated/ Untreated

1a MH C-ln MH Untreated 1b MH C - ln MH Treated MH B - sewer 2 Treated crown (D/S) 3 MH B-ln MH Treated MH B - sewer 4 Treated crown (U/S) MH A - sewer 5 Treated crown /D/S\ 6 MHA - ln MH Treated MH A - sewer 7 Treated crown (U/S) 8 Control ooint Untreated Special Sample 9 Treated (Roof D/S of B)

n.d.

= No data

D/S

22/08/03 24/09/03 02/12/03 05/03/04 23/06/04 22/09/04 08/12/04 01 /03/05 10/06/05 06/09/05 15/09/06 pH after pH after pH after pH after pH after pH after pH after pH after pH after pH after Initial 1 3 6 9 12 15 18 21 24 36 pH

month

months

months

3.9 n.d

3.6 9.6

5.8 10.1

4.7 7.5

months months months months months months months

3.0 9.1

2.7 9.0

3.3 9.2

3.2 9.2

2.7 9.3

3.0 9.5

3.7 8.3

3.6

9.3

9.6

9.1

8.9

7.4

8.3

6.1

7.6

8.5

4.2

3.7

9.8

10

8.6

9.4

9.2

9.2

9.2

9.3

9.4

8.7

3.4

9.5

9.3

9.4

9.1

8.4

8.2

8. 0

8.2

8.4

6.4

3.6

9.5

9.7

8.9

9.5

9.3

8.5

9.1

8.3

8.6

6.8

3.6

9.9

9.8

9.4

9.5

9.5

9.4

9.3

9.3

9.4

8.9

3.9

4.1

2.9

4.9

4.0

3.4

3.5

3.4

3.2

4.2

3.8

3.5 .

3.2

2.9 .

3.9 .

3.2

3.0

2.8

3.0

2.9

.

.

.

3.4 .

3.8

9.5

.

= Downstream

U/S

= Upstream Figures 8 and 9 clearly show a consistent cover of SulfaLock HiGel™ in che created areas. Figure 9, taken after scrapings had been removed for analysis, reveals che underlying concrete. Observations made during each resting period consiscencly nored the difficul ty in gain ing a sample from the created maintenance hole sections, requ iring a ch isel co obtai n samples, which ind icates the hardness of rhe SulfaLock HiGel™ coating,

S1n1 Soucl HIG1I Trial S1werW1II pH • l/22/2003 pH prio, t o ~ and D 1'U112003 pH an.,- 3 months • 8123/2004 pH aft.r 9 months a 12N2004 pH lftM' 15 moncha 0 8/101200S pH lfttt 2 1 monthl 0 1111MooepHoller3"montt>t

140

~ ~

120

~

2

.

..,,_bOn

• 8'24'2003 pH after applcltlon (30 days) 0 31512()04 pH a ft.,.8montht

0 -•

D9122/2004 pH 1nor 12 monthl 0 3/1/2005 pH aft.,. 18 month, a 9Ml2005 pH al\er2-4 months

100

80

'i 60

4.0

2.0

0.0

-

,,.-__..c ..

-........ c.....,., 1,._._.,_...... .,.,...... ... ..,., 4...,.._.,_........................... ,...,_.A....,. ,.,..._.,_....,..,l,..._.,...,,..,._ ., .....,..

..,...

A.~

..........

_ ....,.,

THtPolnt

Figure 7. HiGel™ Sewer Spray Trial Results, 36-months after treatment. crown, racher than vercically down rhe walls of rhe sewer. T he theory was rhar sul phuric acid is generated ar che co p of rhe sewer and runs down along che sewer walls. As such, che special sa mple may exhibit a lower pH. However, resting revealed a pH of 9. 5 indicating suffi cient coverage. Resul ts after 36-monrhs showed a reduction in surface pH ac several locations, rhe lowest of whi ch occurred at Ml-I B indicating the sacri fic ial HiGel™ layer was exhausted ac char location.

122 FEBRUARY 2007

Water

Northern Georges River Submain (NGRS)

Figure 8. Manho le B showing scra p ings.

Co nstructed in the lace 1930s, the NGRS sewer is a large gravicy sewer comprising rock cunnels, concrete pipe in tunnels and trenches, and various box and pipe section aqueducts crossing rivers and valleys (Figure LO). Concrete box sections were typically 1.8 m high and ranged from 2.1 m wide, up to 3.6 m wide. A total of 13 sections an d 36 manholes and access chambers along 4.2 km of che NGRS required crearmenr wich SulfaLock HiGel™.

Figure 9. Manhole C showing scra p ings.

CCTV In order co establ ish a baseline of existing physical conditions, as well as co monitor che performance of the medium pressure cleaning and HiGel application, an electronic recording of the sewer via CCTV was undertaken for each section. Each section was CCTV'd prior to cleani ng, after cleaning and after HiGel™ application (Figure 11 ).

Coating durability, inspection and observations Inspeccion of che rrial area by CCTV and manned en cry was made approximately four weeks after application d uring which sa mples were collected for surface pH decermin acion and the fo llowing observations made.

The sewage stained walls, as well as rainfall data collected over the 3-year period, indicate rhac th ere were several periods of surcharging. D uring rhese times the carrier would have been filled co the roof with turbul ent flowi ng wastewater. T he subsequent results reveal the strength of adhesion of SulfaLock Hi GeITM and its suitabil ity for functioni ng sewerage systems.

Journal of the Australian Water Association


technical features

Conclusion The results obtained from the Sans Souci trial over the 3 year period show chat SulfaLock HiGel™ can be sprayed on to cleaned sewer walls simply using relatively conventional sewer rehabilitation technology, without onerous preparation and without sewer traverses. Further, the applied coating was observed co maintain surface pH levels at neutral and higher for at least 24-monchs and at most locations for 36-m onths. After 36-months there is an appreciable

Sydnez_

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reduction in pH at several locations, the lowest of which occurred at MH B, with a pH of 4 .2 indicating that the Hi Gel™ coating was exhausted at chat locatio n somewhere between 2 and 3-years. The applied coating exhibited excellent

Figure 10. NGRS Schematic.

adhesion to the concrete substrate through the 36- month trial period and scraping was still required in order to effect removal. In

Surface preparation C leaning of the main tenance holes, chambers, sewer walls and crown was undertaken in Apri l 2006 using medium pressure water spray equipmen t (4.35 bar) attached to the unmanned 'boat' or via an aboveground lance. Figures 12 shows the boat in action. Manned entry was required to assemble the equipment required for medium pressure cleaning, in accordance w ith the dimensions of the sewer to be cleaned. The cleani ng removed loose material (b iofilms, concrete corrosion byproducts, etc) and exposed a fi rm concrete surface to allow good bonding of the SulfaLock HiGel™ produce.

addition, the SulfaLock H iGel™ coating exh ibi ts good resistance to b eing washed off or dissolved during higher than average sewer flows. The trial results suggest that the spray application of SulfaLock Hi Gel™ onto sewer wall constitutes a viable solution to the problem of acid corrosion of sewer lines and enables water authorities to better

Figure 13. HiGel™ Application. Applicatio n of th e SulfaLock Hi Gel™ product was ach ieved in a similar m anner

The Authors

to th e clean ing operation (Figure 13), with

Steve Barclay is Manager Maintenance

man ned entry required to disassemble the

Distribution, Sydney Water Corporation,

cleaning equipment and set-up the H iGeITM application equipmen t . A

steve.barclay@sydne)'\vater.com.au. Stuart

coating thickness of nomin ally 2 mm was achieved.

Maintenance holes and chambers Manholes and chambers were also cleaned,

Figure 11. CCTV boat.

photographed and coated with HiGel™ to ensure all parts of the NGRS protected. W here manholes were greater than approximately 10 m to the invert level, manned entry was required to ensure co mplete records were taken.

Monitoring sewer wall pH The performance of the Orica SulfaLock HiGel™ coating is subject to on-goi ng pH monitoring. Performance is to be evaluated over 12-monthly intervals period by caking samples of che sewer and main tenance hole fll:IIJll,:,01Mi1itru-Dfll1 &UMXt

Figure 12. Sewer Cleaning.

prioritise capital expenditu re on sewer rehabilitation .

surfaces at various points and testing the pH .

Jessop is Business Development Manager NSW & Q LD , Orica Watercare, stuarc.jessop@o rica.com. Sean LeCount is Markee Manager - Wastewater; David McMinn is Senior Field Engineer; Kent Johns, is NSW Manager Major Accounts, all with Orica Watercare.

References Pomeroy, R.D., ( l 974), "Process Design Manual for Sulphide Control in Sanitary Sewerage Systems", EPA 625/ 1-74-005, October 1974. Sydney Water Corporation, 2004, Our Systems and Operations: Wastewater Services, Sydney Water Website, [visited: 05/11 /04] h rep://www.sydneywater.com .au/ OurSystems and Operations/ Tech nological Standing committee on Hydrogen Sulphide Corrosion in Sewerage Works, 1989, Hydrogen Sulphide Manual,

Vol. l. Journal of the Australian Water Association

Water

FEBRUARY 2007 123


technical features

WATER FOR MINING ISSUES OF SUPPLY

-

B Kracman Abstract This paper discusses the significance of mining in Australia both now and in the future, and discusses in general terms rhe consequent challenges and opportunities facing the water industry and water users as competition for limited water resources increases.

Mining and the Australian Economy Australia is in the top fi ve producers of most of the world's key mineral commodities. Our natio n is the number one producer of bauxite and alumi na, lead, ilmenite, rucile, zircon, ran cal um, seco nd largest producer of nickel, zinc and uranium , and th ird largest producer of iron ore, silver, manganese and gold. Australia is presently the world's biggest exporter of iron ore, black coal and gold. M ining represented 8% of rhe Australian economy as measured by Gross Domestic Produce (GD P) in 2004-05. The industry was responsible for $56 billion in exporrs during chat period. This represented about 44% of Australian exports of goods and abo ut 34% of expo rts of goods and services. Preliminary data for 2005-06 indicates rhe value of mining industry exports for chis period was about $68 bi ll ion. Mining and minerals process ing requires water. Growth in mining and minerals processing implies growth in water demand and potential co mpetition for limited water resources with ocher industri es. T his situatio n will create problems and opportunities for the water industry, policy makers and regulators. T he situation is likely to become more pronounced over the next few years and potentially over the next few decades. T he water ind ustry needs to prepare itself for the inevitable policy debates and pressures to innovate and develop solutions to the challenges ahead.

The Forecast for Australian Mining Whilst there has been some recent softening of most base metals prices from the peaks of a year or so ago, prices remain at historica lly high levels. Copper is a leadi ng base metal and demand for it is regarded as a majo r indicator of industrial production. Copper's price has risen during chis decade from its long run average internatio nal price of US$0.90 per pound through $1.40 in 2004 to a peak of $4.00 in mid 2006. In early January 2007 it had serried back to abour US$2.60 per pound. As is widely known, much of the additional metal demand of the last few years has come fro m China. In China, there are two major demands in play. One is exporcs,

where the apparent low cost of transformation and fo reign exchange rates favourable to China have resulted in much of the imported metal being exported to the rest of rhe world as fin ished goods. The other major demand is internal consumption to satisfy rhe lifestyle improvements desired by rhe population to the background of changing demograp hic and economic forces within what is becom ing the world's facto ry. Figure l illustrates the amount of copper demanded per capita co mpared to per capita gross domestic product (G DP) in a range of countries. Ir is likely that the high copper per capita values for Taiwan and South Korea are due to their significa nt export industries in electrical goods. Therefo re, in the fu ture China could exhibit a per capita copper demand of between l O kg if demand cracks that of the US, Japan or Germany, and 30 kg if demand tracks that of Taiwan. In either case, that is substantial growth from its current demand of about 3 kg of copper per capita. More generally, Figure 2 provides an indication of Chi nese per capita consump tion of copper, iron ore, coal and crude oil relative to the average for people living in developed countries. Again, chis provides an indication of potential futu re

35 30 .

• Taiwan

"' ~25 "'

0

~

20

Q.

• South Korea

ia. 15

• Gennany • Japan

0

0 c:,,

10

:..::

• USA

5 • China

The water industry needs to prepare itselffor the inevitable policy debates. 124 FEBRUARY 2007

Water

5

10

15

20

25

30

35

40

45

GDP Per Capita (Jan 2006 US$ x 1000)

Figure 1. Indicative Per Capita Copper Consumption Relative to GDP.

Journal of the Australian Water Association

50


technical features

.

.

.

water 1n m1n1ng demand for these commodities, a particularly powerful forecast when consideri ng a population of over one billion people, or more than twice the population of the US and Europe co mbined. This forecast doubles if demand from India comes on within a similar rime frame and tempo, as well as allowing for moderate growth in the adva nced economies and potentially solid growth in eastern Europe, che Middle Ease, South America and Africa. The sign ificant growth of che world economy is also creating growth in demand for energy as evidenced by che comme nsurate rise in world energy prices. The price of crude oil has risen chis decade from below US$20 per barrel co about $80 before settling back co around US$55 per barrel in January 2007. The increase in ene rgy prices has added co che mining boom in Australia, with both coal being in great demand and with interest in Australia's continued long term position as major uranium exporter being prominent on the national agenda.

Water Demand in Mining According co Australian Bureau of Statistics estimates, the mining industry in Austral ia consumed about 400 GL or two per cent of national water consumption in Australia in che fi nancial year 2000-01. The industry was mostly rel iant on selfexrracred water, with about 90 per cent of coral water use suppli ed by chis means during the period. The balance of the industry's water demand was sou rced from distribu tion sys rems owned by chi rd parties, generally publicly owned water supply infrastructure. About 70% of chis water demand came from metal ore mining, followed by about 20% from coal mining. Tonnages of ore and coal mined duri ng this period have been estimated at 350 million tonnes raw ore and 400 million tonnes of raw coal respectively. Average water use per to nne of ore mined and per tonne of coal mined is not a useful statistic at chis scale because there are significant variations in relative water use by individual venrnres depending on water availability, mineral type, mining method, mineral quality and the extent of value adding co nducted at che mine site.

35 30 25

~

Crude Oil

-

copper

,.._Coal

-

QI

iron Ore

E20 C QI

e

15

QI

-

- -

a..

10

5 0 1985

1990

1995

2000

2005

Year Figure 2. Indicative C hinese Per Capita Consumption Relative to that of Developed

Countries.

annual rate of 8% in value terms during chis decade. This growth is reported co comprise an average increase of 3% in prices and 5% in volume. The average 5% annual growth in volume over che 5 years co 2006 suggests chat the industry may now be consuming about 510 GL of water per annum. le is likely chat mining in 2006-07 wi ll consume a larger share of the nation's water resources than it did in 2000-01 , which is understandable given its growth.

However data co validate chis assumption is nor yet available. Water is used in mining for a range of purposes. Potable water is required co service the drinking, cooking and hygiene needs of mine sire personnel as well as for industrial uses requiring water of chat quality such as equipment and space cooling around the mine site. Reasonably good quality water is preferred for construction and developmental activities

Protect your Water Stor~ge

Australian exports of both metal ores and coal have grown at an

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Journal of the Australian Water Association

Water

FEBRUARY 2007 125


technical features

. .

.

water 1n m1n1ng around rhe mine sire, particularly for batch ing concrete, as water quality can have a material effect on the strength and durability of co ncrete. Dust suppression both above and below ground level can be significant water consuming activities, bur lower quality waters can generally be tolerated subject to occupational health considerations. Dust suppressio n is important from an occupational health and safety view point with considerations including rhe effect of dust and its constituents on visib ility and on operator health. Excess dust can also increase equipment maintenance issues and have unfavourable environmental impacts. Dust generation will be influenced by the type of mine, i.e. whether underground or open pit, rhe geology of the mine, rhe behaviour of rhe over burden and ore to blasting and handling, local weather and importantly the design of the mine and supporting infrastructure. The amount and quality of water required at a m ine site will depend on the unit processes employed beyo nd rhe ore stockpile. Ar one e nd of the continu um may be an iron ore m ine where the only additional unit processes may be crushing and loading into rail cars for transport to export loading facilities. Ar rhe other end of the continuum may be a mulri-meral m ine with an integrated processing facil ity including milling, flotation, leaching, hyd romerallurgical separatio n, extraction, smelting, refining, casting, electro-refining and electro-winning. Many of these unit processes will incorporate new water and recycle circuits to assist in driving the processes, optimise chemical reagent use and conserve water. Supporti ng the main stream unit p rocesses may be other water demanding processes including acid making, steam making and power generatio n. T he waste water streams also need ro be managed to protect the environmen t and ensure that rhe waste rock particles, spent reagents, waste products and traces of unrecovered metals, collectively referred to as rails are properly disposed of. The availability and cost of water of the required qualities is a factor in determining the overall mining and processing plan for each venture.

Basic Water Economics in Mining The Australian Bureau o f Statistics (ABS) creates rhe Water Account, Australia in

126 FEBRUARY 2007 Water

wh ich data from a range of sources is consolidated, providing a strategic snapshot linking water data to economic data. From the data published in for 2000-0 I , mining was reported to have consumed 400 GL of water for an industry gross value added (IGVA) of $34 billion, or $85 million per GL. Manufacturing consumed 870 GL for an I GVA of $73 billion, or a similar $84 million per GL.

In comparison,

agriculture was reported to have consumed 17,000 GL of water (mostly for the irrigated secror) for an IGVA of $20 billion, or $1.2 m illion per GL.

Where mining and agriculture IGVA stops and manufacturi ng IGVA begins in terms of value adding is unclear, but the above data p rovides good trend information. T herefore, o n the basis of monetary value to the Australian economy, mining and manufacturing provide much berrer remrns for water used than agriculture, Ir also informs the price-value equation and indicates char m ini ng can generally afford to pay substantially more for water than agriculture can .

Water Supply Options The water supply optio ns for mining are dictated by location and cost. In general terms, rhe possible sources are surface waters, ground waters, reclaimed waters and seawater.

so me allowance for environmental flows to sustain the ecology of these natural assets. The extent to which sufficient capacity of our surface waters has been allocated to the long-term well-being of their dependent ecologies has recently been highlighted. Ir is a complex and multi-dim ensional subject. As the demand fo r water from these sources has begun to approach and perhaps exceed their long term supply capacity, a marker for trading this water has developed as a normal response to chis tension. This marker provides the opportunity fo r water to be traded between industry sectors in a manner char could result in less water being owned by the agriculture sector, with transfers occurring to rhe min ing sector. With h igher mineral commodity prices, water will in certai n circumstances have a higher value fo r mining than for agriculture. Less water used in agriculture doesn't necessarily mean reduced value of agricultural production or rhe contraction of regional communities. There have been many examples in recent t imes where sales of water allocatio ns have raised the necessary cap ital funds to implement improved water management infrastructure resulting in increased values of agricultural production for less water use, with rhe sold allocation going on to generate additional economic activity, or bought by government to address over-allocation and to redress ecological impacts.

The water quantity situation changes North of the Tropic of Capricorn. Approximately 95% of Australia's run-off occurs in this region, but less than 5% of the nation's population lives there. However much of this region is also recognised for its natural assets including wild rivers, rainforests, wilderness, prist ine coastal zones and adjacent coral and reef complexes, creating som e potential tensions between conservation and development. Australia's biggest mining stares, Western Australia and " Queensland, occupy large areas of the tropics, as does the N o rthern T erritory where mining activity is predicted to accelerate. Whilst annual rainfall in rhe tropics is high, ir is also seasonal. The monsoonal period typically runs from December to March. During this period, rhe rare of precipitation can be so great that it can require rhe suspension of surface operations for considerable periods of rime. 0 -~ This seasonality also means rhar sustained demand for water may on ly be satisfied by rhe col lection and storage of water Figure 3. The Extent of Austra lia's Great A rtesia n Basin . Surface waters in the form of rivers and lakes are relatively scarce in Australia, especially inland and below the Tropic of Capricorn where m any of our mines and prospective mines are located. Where these surface waters exist, water quality is generally very good and co nsequen tly much of the resource has already been allocated to municipal and agricultural demands with

A

v

Journal of the Australian Water Association


technical features

.

.

.

water 1n m1n1ng in dams during the wet season for use throughout the dry. Ground waters throughout Australia are highly variable in q uantity and quality. That said, Australia has been fortunate in that one of the wo rld's most significant underground water resources, the Great Artesian Basin (GAB), covers a significant part of the continent including the scares of Queensla nd, New South Wales, South Australia and the Northern T erritory. Figure 3 illustrates the approximate geographic extent of the GAB. Water sourced from the GAB is of relatively good quality with total dissolved solids (T DS) rypically in the range of I 000 mg/L to 3000 mg/L. Water bores first sunk over one hundred years ago enabled much of Australia's arid regio ns to be used for pastoral pursuits. Many of these bores were free flowi ng, resulting in less than optimal use of the resource. Over the lase decade or mo re, governments have implemented programmes to regulate the flows from these bores. Some min ing companies have helped fund ch is program in recurn for directing some of rhe water savings to allocations fo r use in mining, another example of a 'win-wi n' resulting in a gain in

Figure 4. GAB Mound Spring in Far North South Australia. economic value from a limited water resource. One of the mai n issues concerning water abstraction from the GAB is the draw down effect char added abstraction has on mound springs. Mound springs generally occur ar the margins of the basin, where the aquifer outcrops, enabling water to discharge from chem, each one creating an

THE NEXT GENERATION IN FINE BUBBLE DIFFUSER IS HERE ...

oasis in rhe desert. Figure 4 is a photograph of a mound spring near the southern margin of the GAB in South Australia. The sustained existence of th ese springs means char discrete ecosystems have developed within their vicinity, ecosystems chat can have significant nacural heritage value. Many mound springs are consi dered

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water 1n m1n1ng important environmental sites and they are protected by Commonwealch legislation. The aquifer pressure reductions caused by increased abstractions from the GAB can result in less water flow at the mound springs. U nderstanding the extent of flow decline, if any, chat will be sustainable at each mound spring can only be estimated by modelling and validated by monitoring. In addition to the GAB, there are a number of other known deposits of good quality ground water over the continent. Perth in Western Australia accesses large quantities of groundwater for its metropolitan supply and has a number of other possible sources in the Perth groundwater region. The Yilgarn and Can ning groundwater regions are also significant suppliers of water to the mining industry. Adelaide in South Australia is also underlain by a substantial aquifer complex chat until 1968 was exploited for met ropolitan potable supply until the decision was raken to rely on the River Murray as Adelaide's key water supply source. T he aqui fer contains good quality water chat is presently used in industry and horticulture. Darwin in the Northern Territory has a h igh qualiry ground water resource chat is used conjunctively with surface water to provide a high quality, year-round municipal supply. Many regional communities around Australia access groundwater as either a primary or supplementary source of potable water. Many mines in Australia utilise groundwater as their primary water supply. Throughout inland Austral ia, and outside of the GAB much of the ground water is saline or hyper saline. Some of the hyper sali ne waters are palaeo waters exiting in land locked palaeo channels that were once part of the marine landscape when much of the continent was covered by sea. Over time, the seawater has been concentrated resulting in TDS of greater than l 00,00 0 mg/L. Water of this TDS can be used by some mining and p rocessing operations in the metall urgical circuits and for dust suppression, but a limited source of better qualiry water and/or desali nation is requ ired to meet the potable and better qualiry needs of the venture. Reclaimed waters from non-mining sources for use in mining ventures has potential, albeit limited to situations where suitable quality 'waste waters' are generated within an econ omic distance of the mine demand. A typical example is where domestic sewage from a town or city can be eco nomically treated to the required quality and pumped to the m ine site for use there. However, with the p resent prolonged general drought in Australia, the competition for reclaimed

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water has increased in recent years and it is now much more often seen as an opportuniry for water users as opposed to the disposal problem it was seen as when water was more plentiful. Seawater is another potential source of water fo r mining, either in its natural state or as feed to a desalination plane for the production of better quality water. Some of the palaeo water used in mining is several times more saline than seawater, so the use of highly saline water is not foreign to the mining industry. However, saline water can cause issues in relation to the efficiency of metallurgical processes and in significantly increased costs of additives and reagents in hydrometallurgical circuits. These costs need to be weighed against the cost or even the practicality of sourcing better quality water for process use. Corrosion can also be an issue, but in the highly abrasive mining enviro nment, equ ipment life is generally influenced by a range of service factors and the corrosiveness of process water is not necessarily a major consideration . The fate of the salt remaining after the water from highly saline groundwater and seawater evaporates is an environmental consideration. Disposing of the sale along with waste and rails may be a technically acceptable option, but one chat may need perception management. A sea water reverse osmosis (SWRO) desalination plant is an option which can be considered for arid regions, even when the m ine is some distance from the coast. The likely major commun ity issues of concern with SWRO are the environmental issues in d isposal of the reject b rine back to sea and greenhouse issues arising from the power requirements of the desalinatio n plant. For the miner, the commercial issue of cost will be the major factor in the business case for the venture. In significant volumes and assuming an energy price of about $50 per megawatt hour, the total cost of potable water from a SWRO plant will be about $1.20 per kilolitre. There will also be signifi cant costs involved in conveying the water from the coast to the mine-site. Depending on the other options avai lab le and their costs, seawater desalination can offer a practical and cost effective solution to the water needs of mining ventures. Compared to other options it creates a new source of good qualiry water and offers potential benefits for nearby regional co mmunities to improve or supplement their water supp lies, especially in arid regions.

Journal of the Australian Water Association

Conclusions Demand for water from m ining and associated value adding manufacturing is likely to continue to increase over the next few years. This demand can be satisfied in a number of ways, depending o n the needs, locat ion and water availability of each specific venture. There will be an increased focus on the eco nomic efficiency of water use and there is a need fo r government to further develop water use planning guidelines and assist in establishing and maturing water markets to enable Australia to make best use of its water resources. W ithin an appropriate policy framework, water will be traded from low value irrigated agriculture to higher economic value and more sustainable uses including mining and m inerals processing. The economy will be able to expand with less water used in industry and with appropriate allocatio ns returned to the environment. T he mining industry w ill continue to be cyclic, so water use planning and allocation requires a prudent level of diversification and the ability to respond to changing circumstances. Sometime in the futu re, imbalances of global energy supply and demand will be the likely cause of a general economic downturn. T here wi ll be ongoing pressure on industries to increase their water use efficiency. In mining chis will mean better water management and control of evaporation, increased water recycling and reclamation, and adopting newer tech nologies such as paste thickening of tails to enhance water recovery. In certain circu mstances seawater desalination will be justified. New pipeline systems will be required as it will often be more cost effective ro cake the water to the ore than cake the ore to the water.

The Author Borvin Kracman is a Principal of Arup and its National Water Leader. Email borvin.kracman@arup.com.au

References Minerals Council of Australia www.minerals.org.au Huntley's Invest ment Information Pty Ltd (2006) Commodities Special Report Australian Steel Institute (2006) Steel Construction journal ISSN 0049-2205 Australian Bureau of Statistics 4610.0 Water Account, Australia, 2000-0ls


WATER: ISSUES OF QUANTITY AND QUALITY J Taylor, S Pape Abstract

Table 1. Water usage in mining .

Th is paper reviews the issues of water supply and disposal in che mining and mineral processing secrors, with reference ro their impacts in the broader social and environmental context. le cons iders the water cycle both during operations and after mine closure, embraci ng both quantity and quality issues associated with surface and grou ndwaters.

Mining:

Other:

• Process water.

• Community water users.

• Tailings discharge.

• Discharge - downstream water users and environmental flow requirements.

• Dust suppression. • Fire fighting. • Vehicle woshdow n. • Amenities, potable water supply. • Drilling.

Water Use

• Dilution (prior to discharge).

Table I lists a wide range of water uses char are commonly associated with mine sires. Nore char ir includes rhe water requirements of surrounding com muni ties and the environment downstream of mine sires. All of the water uses listed in Table 1 can potentially be com promised by issues char can be broadly categorised as eithe r water quantity or quality issues. T his paper subsequently addresses each of these categories in turn, an d considers a range of solutions available fo r managi ng such issues.

• Pit floodi ng. • Rehobilitotion/revegetotion/wetlonds.

Quantity of Water - Issues and Solutions

T he areas of operation of Australian mining interests span not only the varied cl imate of Australia itself (e.g. Tasmania, the Pi Ibara and the monsoonal climate of rhe north), bur also the even more varied climates of overseas operations, ranging from desert ro the very wet tropics. This section firs t considers rhe problems facing mining operations char may be constrained by a limited quantity of water. These are listed in Table 2. In a low rainfall zone (or season) or duri ng a drought, mine operarors char rely on strea m water abstraction fo r processing and other on-sire uses must identi~, alternative water so urces. Loca l dams or reservoirs are obvious alcernacives ro stream water supplies, even if they have robe built ro capture the erratic flus hes of srorms (as in Kalgoorlie). Another option is to utilise groundwater, either by the establishment of bore fields, or by raki ng advantage of groundwater char is extracted as part of mine dewarering processes, even if some treatment is

Figure 1. This image was taken in an ephemeral stream bed adjacent to a mine site in Tanzania, highlighting the issue of limited water availabi lity for both mining operations and local community needs. required. Enhanced recycli ng of water onsire within the process plant itself may alleviate the siruarion, though this can generate problems with increasing concentrations of salts and other chemicals. Evaporation of srored surface water can lead ro significant water loss at mines situated in arid zo nes. Options for minimising

Table 2. Issues with Quantity: Limited Water. • Low rainfall/drought: - Limited availability of water. • Evaporation: - Loss of supply. - Process losses (e.g. tailings). • Groundwater/ seepage losses.

Unwanted seepage of water from railings dams will reduce rhe volume of supernatant water rhar is available fo r on-sire recycling (as well as potentially polluting a gro undwater resource). Seepage can be prevented if necessary by the insrallarion of impermeab le barriers, created from either clays, if available, or geotexrile materials. ln most arid zones, there can be in tense competition for limited water resources between mines and local commu ni ties, or even between competitive mines and othe r industry. Figure I shows an

• Competition with other users: - Stock watering, irrigation, environment, potable uses. • Political/Legislative restrictions. • Corporate objectives. • Sustainability of resource: - Groundwater abstraction.

This article has been drafted from the presentation to the A WA Conference 'Water in Mining', Adelaide, September, 2006.

evaporation rares include the use of covers or perhaps aq ui fer srorage and recovery where the geological profile is suitable.

• Logistics: - Location of water.

Operational issues may be relatively easy to manage, but postclosure issues must dominate planning.

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water 1n m1n1ng extreme example of competition fo r the groundwater below an ephemeral river bed . Such matters often need to be negotiated by water trading, even by outright land purchase. Equally common are mi ni ng situations in which there is an excess quantity of water (perhaps seaso nally) and certainly mining below the water table often presents its own problems of constant dewatering Table 3 lists a range of problems relating to excess water at mine sites. The solutions to these issues are wellknown. High rainfall and seasonal snowmelt can be planned for, with storages and pumps, combined with careful civi l engineering of diversions, drains, culverts, spi llways and high Row by-pass strucrures. Note that in so me locations, the seasons oscillate from severe drought to monsoonal downpours. Landslips can be a major hazard and maintenance of strategic vegetation is one key method to reduce the risk. Quality of Water - Issues and Solutions

All uses of water are affected by its quality, but the key concerns specific to mining operations are the effects of water quality on processing, both in the mineral d ress ing operations and any chemical separations. Once the water discharges from the mine site, the effects of quality on drinking water for humans, stock and wi ldli fe, including fish and birds as well as plant life, both instream and riparian , have to be considered. Discharge to aquifers may have just as sign ificant effects, even if delayed. The main constituents of water that can adversely affect water use, both on and offsite, are listed in Table 4. The advanced technology of modern mining and mineral processing has rhe potential to have severe effects on the environment, as indicated by

- Erosion.

range of processes that are available for this purpose. When cya nide combines with sulfur, thiocyanate can form. Identifying the impacts of thiocyanate in discharges is difficult due to the complexity of the analytical methods.

- Storage.

Acidity and alkalinity

- Dealing with excess surface runoff.

Water containing excess acidity or alkalinity often requires neutral isation if it is to be recycled on-sire or discharged to the environment. A significant problem at many mine sites is that of Acid and Metalliferous Drainage (AMO). Methods that can be used to minimise, control and treat AMO are discussed in a separate paper (Taylor and Pape, this issue) .

Table 3. Issues with Quantity: Excess Water. • High rainfall/snow melt/dewatering/process: - Flooding.

- Geotechnical stabil ity. - Geochemical stability. - Infrastructure damage. - Loss of production. - Loss of ore. - Underground/surface mine dewatering.

the broad range of potential contaminants identified in Table 4. Fo rtunately, solutions to mine site water quality problems are many and varied.

Salinity Salinity in water cannot be destroyed, ir can only be concentrated into a lower volume waste stream (by treatment) or into a solid (e.g. by evaporation). A range of membrane treatment processes, such as reverse osmosis, is available for the treatment of salin e mine water. 1n truly arid areas, solar evaporation basins are one solution. In extreme cases, mine operators must resort to modern evaporation systems, some even yielding solid salts for trucking. In monsoonal zones, it is possible to tempo rarily store concentrated water until screamAow allows sufficient dilution in rhe wet season. Note that discharge of sulfate-containing waters into a wetland can carry with it the risk of H 2S generation in anaerobic zones.

Cyanide and thiocyanate Cya nide is often used in gold processing and it is essential that residual cyanide be destroyed on-site before discharge of waste screams to rhe environment. Table 5 lists a

Metals Mine waters can contain virtually the whole periodic table of metals and metalloids. Sometimes passive treatment in engineered wetlands will suffice, with the metals adsorbed or precipitated in the anaerobic sediments. However, when metals are present in greater co ncen trations, active physico-chemical treatment may be necessary. Refer to rhe paper on Acid and Metalliferous Drainage (AMO) for further discussion of methods for treating metal liferous waters (Taylor and Pape, this issue).

Organic chemicals and nutrients Ar mine sites where ammonium nitrate is used for blasting activities, traces of explosive residues can carry nitrogen into the groundwater and runoff. Th is can be reduced before discharge by directing rhe runoff through engineered wetlands, which can also deal with suspended solids and many organic compounds (e.g. guar gum and polymer Aocculanrs used in clarifiers).

Hydrocarbons Hydrocarbon contam ination may be generated from spills during vehicle

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Journal of the Australian Water Association

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water 1n m1n1ng Table 5. Cyanide Destruction Methods.

Table 4 . Issues with Quality. • Salinity (Cl , S04 , NO3). • Process/ mining chemicals: - Cyanide (CN, WAD CN, SCN). - Acids (HCI, H2SO,, HNO3).

• Cyanide destruction methods:

• Turbidity/ suspended solids:

- Caro's acid.

- Process woter/ stormwoter.

- Hydrogen peroxide.

• AMD:

- INCO process.

- pH, acidity, salinity, metals.

- SART (Sulphidisotion, Acidification, Recycling and Thicken ing).

- Metals

• Hydrocarbons.

- Alkalis (e.g. NoOH).

• Nutrients.

- Oxidants (e.g. H2O2).

• Radioactive materials.

- Iron-cyanide precipitation.

- Explosive residues (e.g. NH4 NO3).

• Dissolved oxygen/ ORP.

- Activated carbon polishing.

- Drilling fluids (org/inorg).

• Biological contaminants.

- Chlorine dioxide.

• Human health (water borne diseases).

- Alkaline chlorination.

• Gos emissions/ odour.

- Biological treatment.

- Others (xonthotes, copper sulfate, lead nitrate, etc.)

- Natural degradation.

refuelling and/or leakage from storage tanks, particularly in maintenance bays and fuel stations. I nterceprion drains and bunding are necessary at th ese locations, in addition to separators, skimmers and/o r booms, and sometimes high technology techniques, if the runo ff water is to be used fo r processing. Procedures to enco urage che reporting of hydrocarbon spills are viral for immediate effecti ve creacmenc, such as soil composting.

Turbidity Careful civil engin eering, including revegecari on, can reduce the sediment load which inevitably occurs during rainfall events. Traditional erosion and sedimentation control such as basins, silt fences, straw bales, culverts and gabions are often required co co ntrol turbidity issues. Where discharge li mits for turbidity are strict, treatment using coagulants in cl arifiers and thickeners may be needed. Certainly, discharge and/or run-off from railings dams, or any other potential contaminant source on-sire, must be srri crly controll ed. Low dissolved oxygen Deware ring operations associated with both open cut and underground mining operations typically generate water with naturally low levels of dissolved oxygen.

Off-sire discharge of this water can adversely affect fish and ocher aquatic life downstream of the mine sire. T o raise oxygen con centrations co suitable levels, physical ae ration and/or chemical ox idation may be necessary prior to discharge.

Water-borne disease Although minin g and mineral processin g themselves do nor produce organisms, the presence of the employees necessitates precautions. In general, sire am enities should preferably be located away from standing water. However in som e cases, fo r example if a wetland is used fo r sewerage or greywacer crearmenc, rhe con tained nutrients can be of benefit to the biologica l treatment processes. Mosqui to breeding can also be a problem in so me environments, fo r example, where malaria is endemic.

Gas and odour emissions

• SCN- (thiocyanate).

Conclusions Whatever the preca utions taken during mining ope rations, che responsibilities of modern mining extend into the years fol lowing closure of rhe mine, and thi s must be co nstantly in che minds of the opera to rs. le is important to remember char: • Site manage rs, particularly those operati ng in arid zo nes, must keep water recycling possibilities in mind • Treatment CAN solve water quality problems, bur this is rarely cost effective • Nothing bears good pl anning and management • O perational quality iss ues are relatively easy to manage, bu r POST CLOSU RE water quality management issues should be avoided at all costs

W herever sulfates are involved, precauti ons must be taken to minimise reduction to

The Authors

H2S.

Environmental Geochemisr wi th Earth Systems, Email: jeff. raylor@earrhsysrems.com .au. Sophie Pape is a Senior En vironmental Engineer with Earth Sysrems, Email: sophie.pape@ea rrhsysrems.com.au

Where odorous gases are involved in the treatment processes, the usual precautions muse be taken , and covers with exhaust fa ns and scrubbers or biological filters may be necessary.

Dr Jeff Taylor is a Director/Pri ncipal

tel: +61 39769 0666 fax: +61 39769 0699 ema i I: ha nnai ns @ha nnai nst.com.au

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

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ACID AND METALLIFEROUS DRAINAGE (AMD) J Taylor, S Pape Abstract Acid and Metallifero us Drainage (AMD) is the biggest environmental issue facing the mining industry. T his paper reviews the causes and impacts of AMD, and provides techniques for its minimisation , control and rreacmenc.

Overview Acid and Metalli ferous Drainage (AMD), from both existing and historic mines, is the biggest environmental issue facing the mining industry worldwide. AMD has traditionally been referred co as "acid mine drainage" or "acid rock drainage". Any type of mining operatio n chat affects common sulfid e minerals such as pyrite has the potential co generate water pollution associated with AMD. The effects of AMD often continue lo ng after mine closure, when the mine operators have disbanded. AMD affects all sectors of mining, including precious metal, base metal, coal, mineral sand and uranium mines and even quarries. A prime example in Australia is the discharge of AMD fro m the Mr Lyell mine into the King River in Tasmania. Curren cly some 80 tonnes per day of sulfuri c acid, along with iron and copper, is still entering Macquarie Harbour via the King River. World-wide, the Rio Tineo (lie. 'Red River') in Spain gees its name from the iron content of the outflow from copper mi nes char were worked by the Romans, over 2000 years ago (see Figure I).

Figure 1. Th is historic mine site on the Rio Tinto ('Red River') in Spain has been discharging iron-rich AMD for over 2000 years.

Types of AMD "Acid drainage" is formed by the exposure of sulfidic minerals (usually pyrite) co air and water. This process produces a precipitate of ferr ic hydroxide (o range in

colour) and sulfuric acid. Figure 2 is a dramatic illustration of what can happen. Due to natural buffering reactions, it is possib le for AMD co be near-neutral , bu r with a high acidi ty due co elevated metal

AM D can occur whenever pyrite is exposed co air, either in underground workings, in open cues, waste rock piles, ore stockpiles, or railings storages. Some mines uti lise the phenomenon co extract metal from heaps of ore or old railings deposits.

It is crucial to assess AMD risks as ea¡r ly as possible. This article has been drafted based on the author's presentation to the AWA Conference 'Warer in Mining', Adelaide, September, 2006.

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Figure 2. Iron-rich a nd acidic drainage from underground mine workings in western Tasmania.

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water 1n m1n1ng concentrations - chis is referred to as "metallifero us drainage" . W here there is an excess of carbonate materials to completely neutralise the acid and remove metals from solution , "saline drainage" may still be an issue. Thus, AMD can be classified into three types: • Acid drainage: Low pH drainage with high metal concentrations and high (sul fa te) salinity • Metalliferous drainage: Near-neutral pH drainage with high metal concentrations and high (sulfa te) salinity • Saline drainage: Near-neutral pH drai nage, with low metal concentrations bur high (sulfate) salinity

Impacts of AMD The immediate impacts of AMD in an operating mine include: • On-sire, AMD can limit sire water use, corrode infrasrrucrure and equipment, and render the water unsafe fo r drin king or ocher uses if it contains toxic metals (e.g. Cd, Cu, Al). • Off-s ite, AMD can limi t downstream beneficial uses, produce severe ecological impacts (e.g. death of aquatic and riparian life), and po llute groundwater resources. AM D requires expensive re mediation and rehabilitation programs to cope with the po tential long term environmental liabilities. Co nsequently, current mi ning licences often require substa ntial bonds th at are only relinquished when successfu l mine closure has been achieved.

Managing AMD The benefits of managing AMD at mine sires include: • Achieve compliance with government sire discharge co nditions • Minimise im pacts on downstream water quality • Maximise water use on-site

Key Definitions • ' Acid' is a measure of H+ concentration, expressed as pH . • 'Acidi ty' is a measure of both H+ and the mineral (or latent) acidity, expressed as the amount of a lkali necessary to reach neutra lity (pH 8.3), and is generally expressed as ' mg CoC03/L' . • ' Acidity Load' is the principal measure of potential AMD impact at a mine site. It is dependent on acid (pH), mineral acidity (meta l concentrations) and flow rates, and can be expressed as ' kg CaC03/day' .

Figure 3. Active treatment pla nt used for the continuous neutralisation of AMD from a decommissio ned mine site.

• Protect on-s ire infrastructure or processes • Lowe r rehabilitation costs • Lower post clos ure risk. T he approach to AMD management should first involve the identification of all potential sources of AM D (an audi t of all sulfide co ntaining material on-s ire char will be exposed to air and water) and che likely "acidity loads" (see defini tion in Key Defini tions box) chat may be generated

fro m each source. Management strategies should then be developed to mi nim ise and control AMD, and if necessary to actively or passively treat any res idual AM D.

Identification and prediction of AMD During the mineral exploration stage, apart from visual observations and monitoring of water quality, geochemical static tests (e.g. NAPP and NAG tests) can be used to characterise the net potential for acid

Fundamental Research into Treatment of AMD: Evaluation of Reactions and Products Current technologies used to treat acid and metalliferous drainage (AMD) from mine waste rock dumps have been show n to be effective in the short term but AMD reaction and treatment mechanisms ore not fully understood, limiting the effectiveness of assessment and long-term control. A joint AMIRA/ Australian Research Council pro ject to progress this understanding is being undertaken at UniSA (Roger Smart, Jun Li) with Environmental Geochemistry International (Stuart Miller, Warwick Stewart), Levay & Co Environmental Services (Russell Schuma nn), and Boojum Research in Canada (Margarete Kalin). The live main programs in the proiect will: 1. Investigate the reactions with limestone, the main material used to treat sullidic wastes. As well as neutralising acid, limestone appears to slow down the oxidation of sulfides, which lowers the rote at wh ich neutralisation has to be applied, so acid producing capacity is stored for longer periods and this time evolutio n has to be managed. 2. Examine secondary minerals formed by waste treatment processes, often in nano- and microsized particles, for their capacity to store ac idity that may be released later.

3. Assess the silicate and mafic minerals with in AMD wastes that neutralise slowly but continually over the life of a dump helping to control acid and metalliferous drainage without other additives .. 4. Work with AMIRA company sponsors, Zin ifex, Rio Tinto, Teck Cominco and PT Freeport, toking sa mples from their operating sites to study the d ifferent developmenta l stages of reaction mechanisms in the waste and treatments using neutralising products such as li mestone, phosphate rock, and biocides. 5 . Co llaborate w ith Boojum Research o n their ecological engineering projects in Canada over 20 years using natura l microbiologica l processes to ra ise the pH and remove toxic meta ls including sites where metalliferous drainage reaching the surface oxidises and precipitates huge quantities of secondary mi nerals These long-term studies w ill help determine which secondary mi nerals toke up toxic metals such as arsenic, copper and nickel.

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generation from various rock types. In additio n, geochemical kinetic rests can be used to assess rhe rare at wh ich AMD m ay be generated, by column leach or humidity cell rests in a laboratory and /o r trial dump rests in rhe fi eld. Interpretation of the results requires specialise expertise, bur there are some m od els available to assist with chis. A combinatio n of static and kinetic rest resulrs can be used as a basis fo r assessing the risks to o peratio ns (e.g . infrastructure and processing), on-sire water recycling, downstream water uses and environmental values.

AMD management strategies minimisation and control

100

Table 1. Treatment o ptions for acid a nd metalliferous d rai nage.

,~ 1\ ',, ,,,,\ \ ',

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If the potential AMD risks are significant, a man agement plan should be developed , encompassing a number o f options for min imising these risks. Selective m ining and handling of the sulfidic materials may be a possibili ty. Encapsulation of material (e.g. waste rock or railings) can be achieved by soil o r geosynrheric covers to mini m ise in filtrat ion of rainwater. Alkaline (e.g. carbonates or oxides) covers can also be suitable in certain situatio ns. Perm anent inundation of sulfidic material under a water cover is often a convenient way to

t

3000

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Figure 4. Suitability of active and passive systems for susta inable treatment of AMD depends on acidity, flow rate and aci dity load. Conto urs represent acidity load in ton nes CaCO3/day. p revent it from oxidising and generating AMD. In certain circumstances, it may be app ropriate to blend or co-dispose sul fi d ic waste w ith alkaline materials, such as carbo nates. Selection of optimal AMD min imisation and co ntrol strategies depends on a range of factors such as climate, topography, min ing m eth od , material type, mi neralogy and available neutralising m aterials.

bigger issue pose closu re. H owever, if m inimisation and con trol strategies are not sufficient to reduce the AMD risks, then treatment may also be necessary. AMD treatment may involve one o r more of the following methods:

• Physical: wetlands; engineered structures; di lution/ mi xing .

Passive treatment methods:

AMD management strategies - treatment

• Biological: microbial; wetlan ds; phycoremediatio n .

• Open/ Oxic Limestone Drain (OLD)

Treatment of AMD is porenrially a costly part of enviro nmental m anagem ent d uring a mi ning operatio n bur can be an even

• Chemical: ne utralisatio n (most com mon); adsorp tion/absorp tion ; com plexation; chelation ; biological mediatio n ;

• Anoxic Limestone Drain (ALO) • Slag Leach Bed (SLB) • Reducing and Alkalin ity Producing System (RAPS) • Permeable Reactive Barrier (PRB) • Li mestone Diversion Well (LOW) • Aerobic wetland • Anaerobic wetland • Alkalin ity producing cover • Gas Redox and Displacement System (GaRDS)

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134 FEBRUARY 2007

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Acid ity (mg Ca CO,/Litre ) Figure 5. Suitabili ty of passive systems for low acid ity load drainage (see Table l for acronyms). Contours represent acidity load in ton nes CaCO3/day .

Journal of the Australian Water Association


technical features

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water 1n m1n1ng hydroxides or gypsum, on the reagent surface. This "armouring" effect can be partially overcome by agicacion or milli ng.

Conclusions Ir is crucial co assess AMO risks as ea rly as possible in che development of mining projects. Progressive evaluation of che risks, from early exploration right through to operations, enables management costs to be quantified prior to significant disturbance of acid-generating material. Leading praccice in AMD management is a developing science and chere is no 'one size fies all' solution to che issue.

Figure 6. Healthy aerobic wetland used for the passive removal of metals and suspended soli ds from underground mine water. oxidacio n/ reduction; electrochem iscry; sedimentacion; flo cculacion/ filcracion /setrling; ion excha nge; crystallisacion. By far che mosc com mon mechod for treating AMD is neucralisacion (pH control) . AMO treatment systems can be broadly categorised as either "passive" or "active" systems, which differ according co their ability co handle acidity, flow rare and acidity load of the AMD. T he con tours in Figures 4 and 5 represenc acidicy loads in tonnes CaCO3/day, and are based on long term water quality data collected from more than 130 sires. Sustainable passive treatment systems, such as limestone drains, engineered werlands, etc., are generally best suited to AMD with low acidity (<800 mg CaCO/L), low flow rates (<50 Us) and therefore low acidicy loads (<1 00- 150 kg CaCOiday) . In comparison, accive treatment systems can be engineered to accom modate essentially any acidity, flow rare and acidity load. The graphs in Figures 4 and 5 can be used to assess che suitability of various passive and active treatment systems for sustainable AMD treatment. Passive creacment syscems have relacively low capi cal coses (A$5K-200K) and operaci ng costs. They are com monly used for dealing wich AMD from decommissioned mines, and are often suited co coal mines. Active treatment, on che other hand, is relacively expensive due to the requ irement for roucine reagent addicion and supervision, with capical costs often exceeding A$ l OOK and commensurate operating expenses. However

accive creacmenc sys rems can be designed to sui t both operating and decommissioned sites (see Figure 3). Nore chat the reaction of AMD with lime or limestone is hindered by che deposition of creacment precipicaces, such as metal

The Australian Governmenc is in the process of producing a Leading Practice Handbook for AMD management in the mining industry.

The Authors Dr Jeff Taylor is a D irector/Principal Environmental Geochem ist with Earth Systems, Email: jeff. raylor@earthsystems.com.au. Sophie Pape is a Senior Environmental Engineer wich Earth Syscems, Email: sophie.pape@earthsyscems.com.au

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Journal of the Australian Water Association

Water

FEBRUARY 2007 135


technical features

Figure 1. The desa lination plant at Yu lara, with Uluru in the background.

Abstract The abstraction, winni ng and refi ning of minerals is generally a hydrological p rocess, just as rhe original transport, co ncentratio n or formation of most minerals was a hydro logical process. New challenges to the industry are obviously d riven by heigh tened awareness of external or non-process issues such as; environmental concerns, historical practices, and the ult imate site restoration fo r closure. P rocess-wise rhe scarcity and asso ciated quality of water for mineral processing may limit p roduction unless addressed. T his paper summarises some of rhe author's experiences in applying membrane technology to this complex field.

app lications in standard water desalination and a suite of emerging applications and unexpected problems . This paper summarises a few of rhe auth or's experiences with such p roblems . They include: rhe high silica content o f Australian groundwaters, dealing with highly contami nated mine water d ischarges, reprocessing of acid railings, uran ium extraction in situ and water balance control for in situ leaching.

Extending membrane technology to exotic solutions.

Introduction Membranes were introduced to the mineral processing industry approximately 25 years ago for rhe d esalinati on of bore water, however, a large percentage of the early plants did nor live up to expectation. Even though rhe overall principle of operation of membrane-based desalination is simple, there was a lack of app reciation for the cha nges in chemistry chat occur during separation , and for the fluid dynam ics and mass transfer effects at p lay. However, the increasing sophistication of the technology and development of new memb ranes, all ied to experience, has led to very successful This paper has been d eveloped from the presentation to t he AWA Water in Mining Conference, Adelaide, September, 2006.

136 FEBRUARY 2007 Water

High Silica T h is is a common issue in Australia since ground water supplies in remote regions are ancient and bei ng in equil ibrium with the native rocks are high in dissolved silica content, typ ically 30-60 mg/1. The silica content is not collo idal, hence when it concentrates, it precipitates in a series of dehydrating steps. It initially forms an amorphous gel which progressively hardens and very effectively fouls a membrane surface. The solution to rhis is a program of chemical assessment of the water, assessing the performance of anti-sealants, and an operation and management program of rhe risks. Anti-sealants used in heavy doses, such as 200-300 mg/L in rhe rerenrare scream, can be very effective. Care muse be

Journal of the Australian Water Association

taken with pH contro l as this is a sensitive and critical factor. T he presence of magnesium may limit the effectiveness of the above due to the formation of lower so lubility intermediates and iron oxidation can form nucleation sires accelerating precip itate formation . T h e complex interaction of over a hundred various potential p recipitates is determined thermodynamically based on G ibbs free energy models. Management programs incl ude a careful review of rhe drivers (concentrations, water chemistry, variability of these, recovery of rhe reverse osm osis [RO] membrane system, a monitoring p rogram and a rapid response and a routine cleaning program). The adage rhar good control will avoid the need of chemical cleaning is false; these system s operate in a meta-stable state, and it's just a matter of how long, not if. As an example, the RO plant chat was installed for Northern Territory Power and Water at Yulara (near Uluru, previously Ayers Rock) in 2004 was totally 'scaled up' (reduced to about I% capacity permeate fl ow) withi n one week of operatio n about two months after start-up . Ir was effectively cleaned in less than 24 hours, and with suitable antisealant and management p rogram has operated successfully sin ce. Generally the removal of silica from membrane systems is considered impossible, however QED Occtech Services have developed two cleaners that have proven to be very effective. T he cleaning programs


technical features

.

.

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water 1n m1n1ng

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Figure 2. Silica diatom skeletons p resent in seawater.

Figure 3. Early experie nce with evaporation ponds a t Bendigo Mi nes.

were developed from experiences in the mineral processing industry where silica levels of grams per litre are typical. These cleaning programs have been in operation for many years now and achieve long membrane lives.

surrounding rock space. Dewarering involved pumping our the groundwater, from a labyrinth of old interconnecting shafts and runnels. Disposing of rhe water or raising its qual ity for re-use was a challenge. The alkaline water was highly polluted (nor with gold) bur with arsenic, iron, hydrogen sulfide and a significant quantity of BOD. T he latter probably arose from a hundred years practice of dumping rubbish down the numero us old mine shafts! (many fo rmi ng co nvenient disposal shafts in residents' back-yards). The simple answer was to release rhe ground water into shallow evaporation dams, bur chis proved impracticable because ir gave rise ro problems of salty dust being blown onto nearby properties. Further, in a rime of drought, a more envi ronmentally and socially responsible solution was sought. Consequently investigations commenced into rhe feasibility of creating chis water co a re-usable quality.

A simi lar problem ar unrelated sire (co nfide ntially restrictions) was observed in a specially developed process membrane application. This led us to do a posr-morrem on a membrane. We found char the spacer design had an influence on silica precipitation. We also noted that in the process of preparing rhe surface for electronmicroscope photographs, the silica gel resembled cracked mud dehydrati ng under the conditions in the electron-microscope. As an aside, silica ex ists in seawater, bur in rhe fo rm of diatom skeleto ns (as in diaro maceous earth). The diatoms are small enough to pass traditional pre-filtrations systems and if in sufficient concentration can even abrade rhe surface of a membrane, causing what appears to be a chemical degradation of the membrane. Dye resting of rhe membrane and careful examination are required to identify ch is effect.

Mine Water Discharge Recommissioning the old gold workings below the city of Bendigo has had its difficulties for rhe operators. Ir's a significant gold reserve, bur poses unique problems in access and dewarering of rhe

The chemistry of the water was 'challenging'. Arsen ic can be adsorbed in iron precipitates and also rejected by RO membranes if in rhe oxidised As+5, rather than the As+3 stare. The ground water was definitely at a reducing redox. The first attempt was a hybrid process with an airstrip of rhe H 2S (oxidising the off-gas in a biofilrer), further chemical redox, pH correction, addition of more iron sales and precipitation of ferric hydroxide ro adsorb the arsen ic, precipitation in a small earthen dam and finally filtration and RO to reduce rhe TDS and trace arsenic. T he pilot process

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Journal of the Australian Water Association

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FEBRUARY 2007 137


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water 1n m1n1ng was successful, and the process patented, however the initial implementation underestimated the amount of acid required for pH control and che variability (ineffectiveness) of iron floe precipitation in an open earthen dam. An enlarged plane now operates using Veolia's Accifloâ&#x201E;˘ system co enhance the removal of iron floe, before passage ch rough a reverse osmosis plane, yielding a water which is su itable for environmental release or fo r alternative reuse.

Acid Tailings Reprocessing Acid leaching of ground ore is a common mineral excraccion route (e.g. the removal of Fe from mineral sands co beneficiace ilmeni te co rucile) but the acid leachate muse chen be neucralised, the iron and other salts precipitated and separated in a tailings dam, from which supernatant water can be taken off fo r re-use. However, che Government (EPA) insisted on limiting the exposed area of the railings dam , and eventual rehabilitation, with che levying an environmental bond in excess of A$100 M. In chis case we converted an old RO plane for partial recovery of excess acid. Ac pH 2, and at 5 ML/d, we recovered 50% of the acid for immediate re-use. Lime demand was correspondingly reduced, and so was the evaporation load. Recurn on investment was gratifying, and also additional bond demands were avoided.

Extreme Acid Process Liquor An .application fo r a phosphate mine in USA aimed at reducing a US$600M environmental bond. The solution was a unique membrane process comb ined with a tangential flow reaction clarifier for chemical conditioning. Ac pH 0.7 the liquor contained 13 g/L F, 10 g/L P and 9 g/L SiO,. After many attempts by ocher companies we have successfully completed a pilot plant and a demonstration plane and are entering design phase. We plan co treat 18 ML/d, releasing only 5 ML/d fo r neutralisation thus saving che high lime coses and presenting a way forward for che company. The growth in learn ing as co the mechanisms of membrane fou ling, transport behaviour and complex process liquor chemistry will satisfy at lease a handful of PhDs.

Uranium Extraction U3 0 8 is extracted by a number of process pathways, but typically from an acid leach and then by ion exchange or solvent extraction, fo llowed by elution. The eluate may contai n Fe and ocher contaminating metals, which impact of sales specifications.

138

FEBRUARY 2007

Water

Figure 4. QED Occtech Tangential Flow Reaction Clarifier in pilot scale.

These are normally separated by delicately controlled Fe precipitation at a low pH 3.5 producing a very light hydrated floe, which is very di fficult co settle. After suitable bench, pi lot plane resting and modelling, we provided a high recovery mem brane plant which discharged only 1-2% of the flow at corresponding higher co ncenrracion of the floe, replacing large foor-p rinc, and potentially temperamental, clarifiers and problematic thickeners. The use of flocculancs and polymers which can be detrimental co ocher sections of che uranium extraction process are avoided with chis membrane process. This plane forms a part of a larger scheme co improve control of water and salt balances in the process.

Salt and Water Balances Recycling water in a hydromecallurgical process is an excellent policy, but musr be economic. Generally, recycling often causes con taminants, or some particular ionic species or sale to spiral up in concentration. Note chat rhe permeability of various membranes may differ widely for various dissolved species allowing an opportunity for specific ionic balance control. Examples are numerous, but some typical ones are the accumul atio n of chlorides in in situ uranium leaching, ammonium sulfate and resultant ni trate in a nickel refinery, and (in Chile) the vicious cycle of adjustment of calcium and sodium from lime/soda softening chem icals when che recovery of water from neutralisation ponds was attempted. The solution co chis problem was che use of a membrane process based on selective ionic transmission.

Journal of the Australia n W ater Association

Chemical Scrubber Wastes Flue gas scrubber 'bottoms' may be highly contaminated with heavy metals, arsenic, dioxin s, ammonia, soots etc. and cannot be released to rhe environment without suitable treatment. Following a complicated flowsheer, at Blue Scope Steel at Port Kembla, we installed a stripper, chemical precipi tation, a UF tubular system and chem ical and UV oxidation co ensure chat clean brine is suitable for release co the ocean.

Other Applications Examples are: clean-up of 28% HCl; recovery of free cyanide from gold processing for reuse; separation of organics from inorgan ics; removal of process toxins; improved phys io-floc separation; efficiency improvements co Ni and Cu electrowinning processes; and many more.

Conclusions Application of membrane processes co the complexity of modern hydro-metallurgical processes is demand ing, but is yielding significant improvements, not only co the problems of envi ronmental discharges but also co the economics of the processes themselves.

The Author Peter Macintosh, F.l.Eng (Aust), is a director with QED Occcech Services, a company specialising in che development and implementation of chemical process solutions and demanding wastewater treatment. Email: pmaci nrosh@qedocccech.com


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water 1n m1n1ng

THE QUEENSLAND NICKEL WATER RECYCLING FACILITY: SIX YEARS OF OPERATION N Palmer, J Taylor Abstract Brackish wastewater from the nickel refinery operations of Queensland Nickel Pry Led (QNPL) near Townsville in North Queensland has been treated and recycled by microfi lrrarion and reverse osmosis desalination in a water recycling facility (WRF) constructed by United Uril iries Australia (UUA) in 2000. T he facility includes Memcor hollow fibre microfilrrarion, a rwo srage Grahamrek elecrromagneric anriscaling reverse osmosis desalinatio n system using 400 mm diameter membranes Figure 1. The Queensland N ickel Refinery at and a conventional desalination plane. Yabul u near Townsville. A 40 hectare evaporation pond was consrrucred fo r brine disposal. The al, 2002; Palmer and Bedem, 2003) wh ich WRF was financed by QNPL, but UUA produces 32,000 tonnes of nickel. The operates rhe facility under a ren year alliance agreement. refinery is currently being expanded ro increase che production to 76,000 tonnes The water recycling facility has elimi nated per year and will include ore from rhe discharge of wastewater to sea, reduced risk Ravenschorpe mine in WA. Company's of sp ill from rhe ra ilings po nd complex and After the completion of the expansion improved the qual ity of water used in rhe project, process improvements ar che Yabul u refinery. When operati ng at full capacity, refinery are expected to reduce water rhe WRF reduces rhe refinery's new water consumption by about 40%.

Background T he Australian Bureau of Srarisrics reported rhar Australia's mineral exports grossed $54 billion in 2005, about 8% of GDP. Minerals contribute about 26% of Australia's export revenue compa red to 17% for agriculture and 11 % for tou rism. T o achieve this, che mi nerals industry consu med about 400 GL or about 1.6% of Australia's water. Queensla nd Nickel Pry Led (QNPL) is rhe nickel business of BHP Billiton and operates rhe Yab ulu Refinery near Townsville in North Queensland producing a range of high purity nickel and cobalt produces. Approximately 3.5 million wee tonnes of imported larericic ore is rreaced annually using a modified Caro n process (Milsom et This paper has been developed from the presentation at che AWA Water in Mining Conference, Adelaide, September 2007.

Recycling water in a mineral processing plant has problems, but they can be overcome.

co-disposed daily with 7,500T of mill tailings to a 260 Ha tailings pond complex. Tailings pond wastewacers are brackish, contain ing magnesium and ammon ium sulphate, iron and sparingly soluble sales barium and strontium (see Table l), and are unsuitable for direct reuse in the refinery. Prior to 2000, tailings wastewater was stored in railings ponds for evaporatio n or discharged to sea under environmental authority. The Queensland Envi ronmental Protection Agency (EPA) and irs predecessors have regulated QNPL since project development commenced in the early 1970s. The original aurhoriry under the Clean Water Act 1971 permitted a co ncenrrarion loading of specific contaminants to be discharged th rough an ocean our-fal l. In 1997 rhe authori ty was amended ro mass load based criteria allowi ng for discharge of excess waters to Halifax Bay when available storage was insufficient to prevent an uncontrolled spill. A furth er amendment was agreed in 1999 when a risk based approach, based upon accepted modelli ng techn iques was taken. The current aurhoriry stipulates rhat rhe risk of sp ill be maintained ar less rhan 1% in any twelve month period.

Historic Refinery Water Balance

intensity from 260 to 130 kL per to nne of product. The local climate is described as dry tropical, characterised by a three month monsoon season. Annual rainfall varies significantly bur averages l , 130 mm. The refinery's total water requirement is about 24 ML/cl, made up from IO ML/d of groundwater, 9 ML/d from the WRF and 5 ML/d from municipal supplies. The total consumption is expected to increase to 28 ML/d following completion of rhe refinery expansion project.

When rhe refinery commenced operations in 1974, water was successfu lly reused in rhe plant with no additional crearmenr. Ocean discharge of excess waters was undertaken on a campaign basis when required to maintain spi ll risk compliance. Plane upgrades and capital investments during rhe 1990s extended the life of the refin ery well beyond irs initial design scope, processing a range of imported ore types and producing high purity and value nickel and cobalt produces. The requirement to use high quality water in many of the plant processes dictated char reuse opportunities diminished and used process water had to be stored in the tailings ponds.

Following use in che refinery, approximately l 3ML of spent process waters are

Drainage from the refi nery footpri nt was directed to rhe railings ponds in 1997 co

Journal of the Australian Water Association

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FEBRUARY 2007 139


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water 1n m1n1ng contain pocencial contamination from refinery activities. The railings facilicy also has a network of interception trenches char recover and recurn seepage waters co che impoundment. These developments combined co put the tailings pond wacer balance inco significant surplus and the requirement for routine ocean discharge to maintain spill risk became almost concinuous until the construction of the Water Recycling Facility (WRF) in 2000. However, the years 200 1- 2004 were dry seasons where tailings pond evaporation exceeded inflow and there was limited surplus for recycling. QNPL has mo nitored the marine environment continuously with annual ecological assessments of Southern Halifax Bay. These assessments demonstrated that there has been no significant ecological impact from the operation of the outfall. Nevertheless, EPA considered the water balance surplus and routine discharge of excess warers ro Southern Halifax Bay, The Grear Barrier Reef Marine Park and World Heritage Area undesirable and unsuscainable as a consequence of the pocential fo r short and long-term effects on nacural aquatic environments from elevated nitrogen and metal loads. QNPL recognised that che praccice was in conflict with its 'triple bottom line' operating philosophy, and was no longer a viable long-term strategy for water management. Working closely with EPA, QNPL decided co cease routine discharge of excess water via the oucfall by developing che WRF. Studies were undertaken on options avai lable co address che water imbalance. These included increasing pond evaporacion area and minimising plant water use. A sophisticated yet reliable , prediccive spill risk model was developed and used by site management co assist in chis process. The studies recommended a custo mdesigned WRF using microfiltration and reverse osmosis cechnology as the besc longcerm, high impacc solution. The WRF would address the imbalance and manage spill risk, by removing up to 12 ML/day of water from che tailings pond and treating it co a quali cy that would permit reuse in the refinery.

United Utilities United Utilities Australia is part of the worldwide operations of United Utilities pie of the United Kingdom. Australia's first build, own, operace, transfer water treatment plant was commissioned by UUA in 1994 for Melbourne Water at Yan Yean. UUA also owns and operates water treatmenc plants at Macarthur for Sydney Water, ten 140 FEBRUARY 2007

Water

Table l . QN I Yabulu WRF - Raw Wastewater Specification. Parameter

Temperature (C) pH Suspended Solids (mg/L) Turbidity (NTU) Total Dissolved Solids (mg/L) Conductivity (mS/cm) Bicarbonate (mg/L as CaCO3) Carbonate (mg/L as CaCO3) Total Ammon ia (mg/L) Total Organic Carbon (mg/ L) Silica (mg/L) Chloride (mg/L) Fluoride (mg/L) Sulphate (mg/L)

Range

20-32 3.2-8.5 0-20 2-1 0 5,000-7,500 7,000-9,000 10-20 <l 400-800 5-10 20-60 180-400 0.5-4.0 3,500-5,000

rural filtration plants formi ng the Riverland project and the Victor Harbor membrane bioreactor wastewater treatment plant for SA Water in South Australia and has been appointed the Operacor of the new Southern Region Wacer Pipeline in Brisbane. UUA was inviced co submic an Expression of In ceresc for che WRF in April 1999 and offered che novel GrahamTek electromagnetic field (EMF) anciscalant reverse osmosis system, developed in South Africa. After being selected to proceed with the project, a GrahamTek plant was built in 2000, and chis plant was further upgraded in 2003 to improve membrane cross flow in the GrahamTek process and co add further conventional trains co reduce overall RO membrane flu x.

Variability in Tailings Water Quality The salinity of tailings water varies seasonally between, on average, 5,000 mg/L TDS in the wet season up co 7,500 mg/ Lin the dry season (see Table 1). The recorded extreme range has been 3,500-9,750 mg/L. There is also a high temperature range from 20-35°C. In addicion, the limited data-set of hiscoric ta ilings pond water quality at the rime of designing the plant suggested chat each wet season (su mmer), the pond pH dropped from the normal dry season (winter) range of 6.0-7.0 co around 4.5-5.0 for a brief period of between 4 and 10 weeks. Thermal stratification and nicrogen-rich conditions facili tate the formation of reduced sulphur species on the floor of the pond via chemical and biological pathways during the stable dry season. The pH drop is believed co be caused by the re-oxidation of reduced sulphur species to fo rm sulphuric acid during mixing events caused by rain and high wind. The low pH period was also normally accompanied by an increase in

Journal of the Australian Water Association

Parameter

Nitrate (mg/L) Iron (soluble) (mg/L) Ferrous Iron (mg/L) Ferric Iron (mg/L) Manganese (mg/L) Magnesium (mg/L) Calci um (mg/L) Sodium (mg/L) Nickel (mg/L) Cobalt (mg/L) Potassium (mg/L) Barium (mg/L) Strontium (mg/L)

Range

4-10 0.1-0.15 <0.05 <0. l 3-15 400-700 30-100 75-140 0.15-0.6 0.04-0.25 10-15 0.02-0.08 0.4-0.6

soluble fe rrous iron concentration up co 0.7mg/L. This value became the basis of the raw wastewater specification. After these events, more stable weather conditions reestablished stratification in the Autumn and the po nds returned to their normal state naturally. 2,700 mm of rainfall fell at Yabulu during the 1999-2000 wet season, the highest on record. An extraordinary volume of scormwater runoff was directed co the tailings pond storage and much of the water body became deeper than 8111. The unusually deep water column and srable winter conditions during the next six months enhanced the development of reducing condicions ac che bottom of the pond. This increased the pond's abil ity to generate reduced sulphu r species and therefore increased the potential for acid generation during che next period of instab iIity. When the pond became unstable again in January 200 I, the resulting acidification of the pond was unlike previous episodes. The pH dropped fu rther than normal to 3.5 and for a longer period of time. Total soluble iron increased well in excess of0.7 mg/L to a peak of 7.0 mg/L. The effect of the increased ferrous iro n, combined with the existing concentrations of silica and magnesium, resulted in a sign ificant increase in silt density index and massive fo uling of the RO membranes as indicated by increasing inlet and differential pressures across the membrane brine passages. The membranes were cleaned using cicric acid and sodium hydroxide and the plant was shut down for an extended period while the tailings pond quality was restored by natural means. T he wastewater scored in the tailings pond rema ined unsuitable for WRF feed until July 2001. QNPL was responsible for wastewater


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water 1n m1n1ng quali ty and determined co develop a means of removing soluble iron from solution during periods of poor water quality. A new decant and transfer station was installed which also included sodium hydroxide dosing fo r pH adjustment. Acidi fied pond waters were transfe rred co a shallow inrermediare pond Cell 3 (average depth 0.5m) via a seri es of aeration weirs. Th e combination of pH adjustment, aeration , shallow depth and derenrion rime was designed co ensure oxidation of Figure 2. The W ater Recycling Faci lity. rhe soluble ferrous iron ro rhe insoluble ferric state in rhe absence of acid generating processes. remove particles down co 0.2 micron. There T his operated very effectively for 18 is an aucomaric air backwash system wh ich months, del ivering water co the WRF wirh operates at intervals of up to 60 minutes and pH between 6 and 7, and ferrous iron a caustic clea n-in-place (CIP) system which effectively zero. However, co mmencing in auto matically acrivaces after 300 hours May, 2003, rhe dry conditions caused rhe operation. Backwash volum e fo r sustainable level of Cell 3 co fall, exposing large areas of operation has been fou nd to be about 5% of mono-sulphide sediment beach ro air. The che total flow, and is return ed via a sump oxidation and associated acid generation and pumping system co che raili ngs pond. caused a massive upset, reducing pH and An acid C IP sys tem is available fo r ch e MF in creasing ferro us iron concenrracion, ch is system fo r mineral scale bur has not been rime up co 20 mg/L. The water level was required due co the low carbonate restored ro normal by QN PL diverting concentration of che wa ter. railings water and by rain fa ll, and by The reverse os mosis (RO) syste m origin ally February 2004, Cell 3 quality was restored used 400mm diameter GrahamTek pressure co normal. Since rhac time, ma intenance of vessels in two stages. The 40 primary vessels the level in Cell ensured good water quality were arranged in fo ur trains of ten, each has been availab le co che WRF. In 2004, a containing two 400 mm (15") dia 1270 mm much smaller intermediate pond (Cell 4) has (50") long Koch HR membranes for generally maintained suitable raw water desalination of the brackish waters at feed qual ity for the WRF and greatly redu ced pressure up co 35 bar. T welve secondary evaporation losses. T his has allowed che vessels (four skids of three), each containi ng WRF to operate for che fu ll year, ensuring a rwo seawater membranes co co nce ntrate che more regul ar supply for the refi nery. primary brine, operated at a feed pressure of

The Water Recycling Facility T he GrahamTek process for Q NPL using 400 mm diameter membranes was demonstrated by pilot plant operation between November 1999 and April 2000. T he pi lot scale operation triall ed GrahamTek spiral wound microfi lrrarion and subsequencly Memcor hollow, fi nefi bre microfilrrario n which was fi nally adopted for rhe full-scale plant. After satisfactory pilot plane performance, a design, build and operate conrracc was signed by Q NPL and UUA on May 22, 2000. The plane was designed and constructed in just under 7 monrhs by O'Do nnell Griffin Water T echnology and was commiss ioned on December 16, 2000 at a coral capital cost of A$22.5M. A pumping station capable of removing a ner 13.2 ML/d from che rail ings pond feeds rhe Memcor Mi cro-Filtration (M F) system. The MF comprises six skid mounted uni ts each co ntai ning 90 hollow fibre membrane cells which

up to 62 bar. T he primary vessels were connected di reccly to che seco ndary vessels in a rwo-srage co ncentrator arrangement. Feed co the pri mary vessels was from rwo variable speed drive multi stage curbi ne pumps in series for each train. Pressure co che secon dary vessels was boosted by one

Figure 3. The interio r of the W RF showing the Memco r mic rofiltration units on the rig ht a nd th e G raha mte k 400 mm diameter RO vessels on the left.

variable speed drive pump and one pelcon wheel energy recovery turbine in series fo r each train driven by secondary RO reject. Brine from che energy recovery tu rbi nes was then pum ped co a 40 hectare HDPE lined pond fo r evaporation. Because of the eleccromagneric anriscalanr sysrem, no permanent provision for RO membrane cleaning was included in che original plane. Ic was found chat perfo rma nce gradually declined. T emporary clean-in-place (CIP) facilities were subsequencly added co the plane and although mild caustic cleani ng solutions were reasonably effective, ic became evident after rwo years operation the plane was unable co produce more rhan 7 ML/d compared to warranted volumetric production of 10.7 ML/cl. United Uci li ries negoriared an agreement wi th che des ign and conscrucrion contractor (O' Donnell Griffin) in October 2002 to remediare the plant co achieve its warranted capacity.

The Augmented Water Recycling Facility Ir was apparent che GrahamTek plane had been designed wi rh excessive flu x and inadequate cross flow. Ir was decided to modify rhe planr co correct these problems. T he cross flow was increased by changing the ren parallel 400 mm EMF vessels in each of the fo ur pri mary trains co 5:3:2 arrays and rhe existing four seco ndary trains were changed from three vessels in parallel to 2: 1 arrays. These changes were effected by pipework changes, leaving rhe pumps and vessels in place. All the fi breglass 400 111111 diameter vessels were also strengthened co ensure they were suitable for the pressures applied co chem. T o reduce the flux, a co mpletely new conventional primary RO plant was added. T his comp rised two trains of thi rty 200 mm diameter vessels arranged in 20: l O arrays operating ar 65% recovery. T he membrane area was equivalent co the GrahamTek primary RO plant, just over 12,000 m2, increasing rhe coral primary membrane area co 24,000 m2. T his enabled che primary RO flu x co be reduced from 35 co 18 L/h/ m2. A schematic of the remediared plant is shown in Figure 5. During periods of low raw feed salinity, all che concentrate from rhe conventional plant is recurned ro rhe GrahamTek plane. Ar higher feed salinity, rhe proportion is reduced unril ir reaches I 0,000 mg/L ar which stage all co nventional concentrate is retu rned to rhe tailings po nds via the backwash return system.

Journal of the Australian Water Association

Water

FEBRUARY 2007 141


technical features

describes a widely accepted general rule to avoid magnesium silicate scaling in RO membranes. For RO feed waters of pH less than 7.5, the product of magnesium and silica concentrations should be less than 40,000. T he product for the WRF secondary RO is 390,000 or ten times the suggested value indicating a serious potential for scaling. Auropsies have no t revealed evidence of sign ificant silica scale. Similarly, the presence of barium and strontium with sulphates also suggests a strong potential for scaling. Use of antiscalanr to prevent barium sulphate precipitation is normally considered suitable up to a maximum supersaturation of 60 rimes. Analysis of the average feed water suggests barium supersaturation at 140 rimes at seco ndary RO.

The EMF antiscaling system has been retained on the GrahamTek plane. However, provision h as been added for chemical antiscalanr dosing to both GrahamTek and rhe conventional plants. Permanent clean in place systems have been added for both the Grahamrek and the conventional plants. T he remediatio n project was completed in M arch 2004 at a cost of $7 m. To ensure app ropriate quality for the QNPL refinery, permeate pH is adjusted with sodium hydroxide co within the range 7-8 before being pumped to the refinery reservoir.

Figure 4. The 40 Ho Evaporation Ponds. effective in inducing precipitation of gypsum crystals in bulk solution rather than forming surface scale.

Process Performance The Memcor m icrofilcrarion system has performed consistent with expectations. ln fact, five of the six modules are still operating on their original polypropylene membranes after more than six years producing RO feed water with silt density index (SDI) less than 4. T he average flux is 108 L/h/m 2 and the transmembrane pressure 55 kPa.

Furukawa (1999) also investigated the effect of EMF on RO and, wh ile recognising controversies, concluded that a properly conditioned EMF will affect electron spin resonance so char ions become less likely to precipitate with their counter ions.

Kney and Parsons (2006) investigated the effect of permanent magnetic fi elds on precipitation and fou nd , in a series of repeatable experiments, that when a magnetically condi tioned calcium carbonate precipitate was added to a freshly mixed sodium carbonate and calcium ch loride solution, a secondary p recipitate forms which settles at an accelerated rare compared to rests using non magnetically created calcium carbonate seed. Kney and Parsons concl uded chat surface rather than ionic mechanisms were accountable fo r rhe magnet ic response.

Further, the effe ct of the rapidly alternating magnetic field is thought to cause an alternating potential at the membrane surface, impacting on d ipolar m olecules so char they are energised, reducing rhe concentration polarisation in much rhe same way as increas ing crossflow.

The G rahamTek RO system has enabled the overall RO recovery to be maintained at 85% despite the difficult nature of the feed water. W h ile the mechanism is not clearly understood, the resultant EMF appears to have a positive effect o n the nature of membrane scaling in chat it makes it easier to remove by chemical clean ing. Gehr et al (1995) fou nd in controlled laboratory experiments, that a magnetic fie ld was

Typical WRF feed water quality is shown in Table I. In the seco ndary stage of reverse osmosis, feed silica and magnesium concentrations are about 130mg/L and 3,000mg/L respectively. Weng (1995)

There appears to be inhibition of magnesium silicate scaling. However, the barium sulphate tends to fo rm an

Miaofikration Units

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Figure 5. Schematic of Remediated W RF .

142

FEBRUARY 2007

Water

Journal of the Australian Water Association


technical features

.

.

.

water 1n m1n1ng amorphous deposit which is easily and effectively removed by a mild caustic clean ing so lution. T his rends to support the idea of Parso ns rhar che magnetic field affects particles after they are form ed rarher rhan preventing their fo rmation. The membranes in the GrahamTek plant have perfo rmed as shown in Figure 6. Th e normalised specific fl ux has decl ined over the 2.5 years' operation si nce they were installed in early 2004 from 2.6 ro 1.6 L/ h/ m 2 , resulting in an average annual flu x decl ine of just over 15%. T his is a reasonable result and consistent with manufacturers' expectations. In the same period, despite regular chemical cleaning, the salt rejection has remained almost unchanged at better rhan 99.5%. This means rhe rreared water quality is still as good as when the membranes were insta lled and rhere has been no significant decl ine in memb rane in tegrity.

Cost The cost of operations, maintenance and membrane replacement amount to approxima tely 70c per kL ar 9 ML/d average oucpur from the WRF. T he WRF cost $25111 to consrrucr in 2000 and chis was finan ced by BHP Billito n. UVA estimates rhe annual finan cia l charges for a $25 111 project based on current commercial rares would be approx imately 80c per kL ar 9 ML/d average output. T he tota l cost of WRF warer is therefore of the order of $1.50 per kl at 9 ML/d average output.

Future Water Supply The refinery warer consumption will increase from 24 to 28 Ml/d upon completion of ch e expansion proj ect at the end of 2007. The salini ty of rhe raili ngs water is also expected to increase by 50% which is likely to cause a reduction in RO recovery. Quee nsland Nickel also desires co reduce its water consumption from che Black Ri ver borefield. A source of high quality water is expected to beco me avail abl e from municipal wastewater treatm ent planes on che north side of T ownsville (Farmer, 2006) . These pl ants are being upgraded to improve effluent quality d ischarged to th e marine environment, and the existing Mc Sr Jo hn plane is expected to be replaced by a membrane bi oreacto r. Subject to appropriate commercial arrange ments being negotiated with the Townsville and Thuringowa City Councils, up to 11 ML/d of reclaimed wastewater could beco me available. The prin ciples under which such a scheme could successfu lly operate include the assumption that the project could be constructed and operated so that the impact

Table 2. Raw Water, Process W ater Specifications and Results in 2004 a nd 2006 . Parameter

Raw Water 2004

pH Total Dissolved Solids (mg/ l) Total Ammonia (mg/ l) Total Organic Carbon (mg/ l) Silica (mg/ l) Sulphate Hardness

Process Process Raw Water Process Water Spec Water 2004 2006 Water 2006

5.8 8790 635 17 55 6 150 4230

on the refi nery will be cost neutral. In rhe scheme, consumption from rhe borefield would be substantially reduced, allowing och er users to beneht, but Queensland Nickel would retain rights as a co ntingency measure. le is also assumed char the reclaimed wasreware r would be equivalent in quality co rhe current borefield supply. Reclaimed wastewater as a strategic resource also rends to increase in volume as rime passes which would provide fo r fu ture warer demand.

Conclusion T he Warer Recyclin g Faciliry currently recycles up ro 40% of Q NI refi nery's de mand. Since rhe WRF commenced operation in 200 I, ra ilings pond spill risk has been mai nrained at less rhan I% and sea discharge of wastewater has ceased. Porencial ex ists to supply municipal recycled water from Townsville's upgrad ed wasrewacer treatment planes which will secure Queensland N ickel's fu ture water supplies.

The Authors Neil Palmer is Chief Engineer, United Utili ties Australia, email npalmer@uua.co m.au; Jeremy Taylor is Team Leader, Environmental, fo r Q ueensland Nickel Pry Led.

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Bibliography Farmer, B (2006) BHP Billicon: Water- Our Most Essential Nat11ml Resource A presentation co rhe Mi neral Co uncil of Ausrralia d uring Minerals Weck 29 May- 2 J une in Canberra - www.mincrals.org.au Fu rukawa, D ( 1999) A New Approach far Mitigating Membm11e Fouling Mitigation in Membrane Processes Workshop, TechnionIsrael lnsritute of Technology, Haifa, Israel, Jan uary 27-28 Gehr, R; ZA Zhai, JA Finch and SR Rao ( 1995) Reduction of Soluble Mineral Concentrations in CaSO4 Saru rated Water using a Magnetic Field Water Research (Elsevier) Vol 29 No 3 pp 993-94 0 Kney, AD and SA Parsons (2006) A Spectrophorometer Based Srudy of Magnetic Water T rearmenr: Assessment of Ionic versus Surface Mechan isms Water Research, 40: 5 17524. Milsom, J; N Pal mer and M Smallwood (2002) Reverse Osmosis Desalinatio11 of QN! Yabulu Nickel Refine1y Wastewater far Reuse International Water Association World Congress, Melbourne, April 2002 Palmer, N; and C Bedem (2003) Reuse o/Nickel Refinery Wastewater by Microfi!tr11tio11 and Reverse Osmosis Desalination Internarional Desalination Associatio n Water Reuse and Desali nation Confe rence, Singapore, February 2003 Weng, PF ( I 995) Silica Scale Inhibition and Colloidal Silica Dispersion far Reverse Osmosis Systems Desalination (Elsevier) Vol I 03 pp 59-67

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0.1

Figure 6. Norma lised Specific Flux for the GrahamTek RO l Membranes. Journal of the Australian Water Association Water FEBRUARY 2007 143


.fereed paper

INTERNATIONAL COLLABORATIVE RESEARCH ON DISCOLOURED WATER J Q J C Verberk, C Doolan, A Jayaratne, P R Teasdale, J H G Vreeburg, K O'Halloran, L Hamilton, D Vitanage Abstract The majority of customer complaints for water authorities are related to dirty or discoloured water events. In the past two years, the Co-operative Research Centre for Water Quality and Treatment, (CRC), the Netherlands Kiwa Water Research (KIWA), Delft University of Technology (DUT ) and Griffith University in Australia, have excha nged personnel, knowledge and resources to develop tools that allow improved understanding of processes leading to generation of discoloured water. T his paper summarises the outcomes an d demonstrates exam ples of the successful application of the Water Quality and Treatment's Particles Sediment Model (PSM) in the Netherlands and the trialli ng of the KIWA Re-suspension Potential Method (RPM) in several Australian water utilities.

Introduction The processes that lead to deterioration of water quality in distribution systems are well understood, but are difficult to predict or monitor in situ, in comparison to the water quality processes in treatment plants. These processes, as indicated in Figure I, are: • Sedimentation and re-suspension of particles/sediment entering the distribution system from che treatment plane,

Planning

Suspended solld11

Suspended solids

Precipitation a. flocculatio n

Bedlo•d lr•nsport

Bedlo•d tr•nsport

Figure 1. Overview o f processes in the distribution network influencing the water quality.

• Oxidation of solutes and/or flocculation of colloids to form new particles within the distribution system, • Corrosion and leaching of substances from pipe materials and installations, • Re-growth of micro-organisms, in particular bio films attached to the pipe wall an d fittings, • Re-suspension of 'old' sediment and biomass, originating from the particles accumulated over time, processes in the distribution network and the treatment plane and increased flows during high demand periods. The drinking water treatment objectives in Australia and the Netherlands are similar

Risk Assessment

ADWG - Frame Work Discoloured Water Critical Processes

Monitoring Techniques

Characterisation of discoloured water

Cu stomer Investigation

----------------------------------I

Knowledge capture, risk assessment and : ______ management support system _______ : Distribution Operational Management Strategies Review

Figure 2. Co-operative Research Centre for Water Quality and Treatment Discolouration toolbox approach.

144 FEBRUARY 2007 Water

Journal of the Australian Water Association

i.e. minimising discolouration and taste and odour, but the selectio n and use of treatment processes differ markedly. In Australia, primary and seco ndary disinfection is a common practice and generally achieved by ch lorination or chloraminacion at a treatment plant, with occasional booster disinfection within distributio n systems to maintain a residual. In the Netherlands, safety of dri nking water derived from surface water and groundwater so urces is ensured by adopting a multiple barrier treatment approach (van Dijk and van der Kooij, 200 5) . Bacteriological safety is achieved without chlorination/chloramination by applying treatment processes such as dune filtration, sand filtration, UV-disinfection, membrane filcracion and ozonation. Although treatment philosophy differs in both countries, the research objectives for the distrib ution system are quite similar. In recent years there has been a mutual exchange of several researchers, studencs and utili ty personnel between Austral ia and che Netherlands to facilitate the development and applicatio n of tools used in the discoloured water research. The key tools presented in chis paper are: • Discolouration Concepcual Model; • Re-suspension Potential Method (RPM);

Identifying the causes of distribution system discolouration events.


• Particle Sediment Model (PSM); and • Particle Coun ting and T ime Integrated Large Volume Sampling {TILVS).

-l

Water quality complaint levels reported by Australian water util ities range from a race of 1.1 to 17.3 per thousand properties (WSM Facts 2005). Discoloured water accoun ts for up co 80% of these complaints. O ften identifying the cause of distribution system discolouration events is difftcul r and the CRC has identified chis as an important resea rch area with in its Distribution Program. A toolbox approach co develop practical sol utions has been adopted as depicted in Figu re 2. T he focus of this project is the development of appropriate cools co better understand processes leading co discolouration events.

>

Critical Processes in Discolouration (Conceptual Model) The C RC, through researchers at G riffith University and with regular input and feedback from water ind ustry partners, has developed a web-based conceptual model co assess the cause and effect of cri tical discolouration iss ues. Nine potential mechanisms of discoloured water formation were identified. Th e user chooses answers to a series of questions about conditions and processes that can either influence or cause d iscoloured water for mation and can minimise or remove discoloured water, from catch ment co co nsumers. A co ncep tual model is then buil t based on the answers to each question and a series of rules encapsulating known influences of disco loured water {e.g. wind-driven resuspension in shall ow raw water storages will increase particle levels). Discoloured water forming and removing processes are shown for each of the nine mechan isms. A high degree of flex ibili ty allows designated users co insert com ments or change rul es co account fo r local circumstances. A literature review of discoloured water processes is also included and users will be ab le to add-co it. Once the conceptual model is built, users can enter a module where the risk of every co ndition or process that causes discoloured water fo r each of the nine mechanisms can be assessed. T his risk assessment also contains a unique featu re, where rhe effectiveness of each treatment process or co ndition can be estimated in order to reduce the overal l risk of discolou red water appearing at a cusromer's cap. In this way, rhe mechan ism of discoloured water fo rmation chat is most likely to lead to custo mer com plaints can be determined. Another important potential use of the conceptual models is for education or 'knowledge capture' purposes. O cher

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F_igure 3. Princ'.ple of performing an RPM (left) . Velocity variati ons during RPM (top right) , four regions of a typical turbidity response curve used to assess th e discolouration risk. modules may eventually be added to chis package. Proactive risk management cools such as the Hazard Analysis and Critical Co ntrol Point (HACCP) has been in troduced into che Australian Warer lndusrry since 1998 . This conceptual model approach has a real potential for use as a decision-support system ro support such risk-based systems. Another potential application for this software is as a platfo rm fo r mass-balance calculations of all material entering and leaving a treatment plan t. 1n any case, rhe synthes is of literature on discoloured water and a method ro eas ily access ch is informarion have been important steps in the development of cools co transfer knowledge from researchers to industry, and between utilities.

Re-suspension Potential Method (RPM) Many water utili ties arou nd the world use customer co mplaints as an ind icator of customer dissatisfactio n. However, custo mer co mplaints are not reproducible or reliable as a para merer co quan ri fy rhe discolouration risk. Trends in such data are difficult co discern. Irrespective of the origin, the quanti ty and mobil ity of deposits determines the discolouration risk. The Resuspension Potential Method (RPM), developed in the Netherlands, is an objective cool based on measuri ng rhe mobility of the sediment in a distribution network {Vreeburg et al., 2004) . The RPM was developed within a successful collaborative resea rch program involving a number of Dutch water co mpanies and has been adopted by many of chem fo r more than a decade. The RPM is used ro evaluate: • rhe need for cleaning water mains and, • rhe effectiveness of cleaning regimes.

The RPM consists of a controlled and rep roducible increase of the velocity in a pipe, but to a level considerably lower than flows used fo r fl ushing. Th is experimentally deri ved cesr velocity is adequate ro distu rb th e sed iments over a short distance, wh ile minimising the chan ce of generating custo mer complain ts during the test. T he hydraulic shear stress, as a resul t of the increased velocity, causes sed iments ro mobilise, increasi ng the turbidi ty of the water. This effect is monitored and translated to a ranking of the discolouratio n risk. The key steps of the method are as fo llows (Vreeburg et al., 2004): • Select rrial sites where there were no maintenance activities, such as fl us hi ng, recorded in the past 12 months. • Isolate the pipe, where the discolouration risk is co be assessed, for uni-direction al flushi ng (An coun et al., 1999) . The iso lated length should be ar least 315 metres. • Open a fire hydrant until the velocity in the pipe has increased by 0.35 m/s above the normal flow velocity (not peak flows). • Maintai n the rest velocity for approximately 15 min utes and then gradually reduce the flow to base level. • Monitor the turbidity in the pipe at the hydrant throughout the fifteen minu tes and afterwards until turbidity retu rns co the initial level. The res ult prod uces the turbidity response curve for the water mains. A typical example is shown in Figure 3, highlighting four regions of turbidity response required to ran k the discolouration risk. The fo ur RPM regions are: • Base level turbidity, prior to the introduction of the hydraulic disturbance, • In iti al increase in turbidi ty, during the first 5 minutes of the hydraulic disturbance. T his peak turbidity is an indicator of rhe

Journal of the Australian Water Association Water FEBRUARY 2007 145


status o f the rop particle layer resulting from the instantaneous re-suspension during the test,

Table 1. Example of ra nking RPM for discoloration risk using a Dr Lange turbidimeter.

0

Turbidity Range RPM Category

• Development of turbidity d u ring last 10 minutes of the hydraulic disturbance, • Re-settling of particles afte r reru rning the flow in the p ipe tO the base level. The duration of this region is important for assessing the d iscolo uration risk. The longer the t ime reg uired tO return the turbidity tO its base level, the greater the risk of generation of d iscolo uratio n complaints.

l

< 3 NTU

2

< 3 NTU

3 4

< 3 NTU

5

<

3333-

< 3 NTU

5 min

For each RPM category a score from 0 (lowest or best) through tO 3 (highest or worst) is assigned. T he lowest rota! rating equivalent tO 'no discolo ration risk' is 0 and the highest rotal rating or ' maximum d iscoloration risk' is 15. T he turbidity ranges shown in Table 1 vary depending on the source water characteristics, treatment method and measurement range and the

• Absolu te maximum value o f turbidi ty during first five minutes of distu rbance; • Average value of turbidity during first fi ve mi n utes of d isru rbance; • Absolute maximum value of turbid ity duri ng last ten mi nutes of d isturbance; • Average value of rurb id ity d uring last ten mi nu tes of disturbance; and

3

10 -40 NTU 10 -40 NTU 10 -40 NTU

> 40 NTU

10 -40 NTU 15 - 60 min

> 40 NTU

• Ti me needed turbidi ty level.

t0

resettle again

> 40 NTU > 40 NTU > 60 min

tO

initial

T he Dutch research student (Anke Grefte), from Delft University, durin g her visit to Australia in 2003, successfully trialled the RPM with a number of water u tilities in Aust ralia (Water Corpo ration in W estern Australia, Brisbane C ity C ouncil in Queensland, and Power and Water C orporation in the Northern Territory) . T he volume of water used in RPM is small compared to fl ushing (1.6 kl fo r a 80mm main and 2.5 kL fo r a 100mm main) and hence the rest could be undertaken even during water restrictions.

Yarra Valley Water's Mains Cleaning Program and RPM Measurements

0 0 0

2211mm

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600mm long P!p,uctlan

Figure 4. Schematic of Yarra Valley Water's RPM Equipment.

7

11

13

16

17

19

21

Time (Mlnut11)

Figure 5. Resu lts of a typi cal pre- and post-cleaning RPM test to evaluate cleani ng effectiveness. 146 FEBRUARY 2007

10 NTU 10 NTU 10 NTU l 0NTU

5- l 5min

accuracy of turbidity equipment. Range of tu rbid ity measurements should be determ ined acco rdingly tO refl ect the specific system characteristics. The five RPM categories are:

The discolourat ion risk can be assessed based on the est imated risk using the matrix shown in Table 1.

2 RPM Rating

Water

Journal of the Australian Water Association

Yarra Valley Water has been investigating al ternative methodologies to optimise their mains cleaning program since 200 3. About 7 5% of Yarra Valley Water's supply is u nfi ltered as the supply is drawn from protected catchments and a majority of customer co mplaints (75%) are related to dirty water due to re-suspensio n of narurally occurring part icles. C u rrently rhe decision to clean each individual water quali ty zone is pu rely based on the level of customer co mplaints. Yarra Valley Water has now incorporated RPM measu rements to its mains clean ing p rogram with the o bjective t0 develop a proactive indicator to d etermine 'when' t0 clean. I r intends to use the Particle Sed iment Model (PSM) to d ecide 'where' to clean once the validation of the new version of the PSM is complete. RPM measurements are being collected at regular in tervals at selected sites across each water quality zone. Data collection is undertaken o ne week prior to cleaning, then after cleaning at one week, one month, two months, th ree months and sixmonth intervals. The duration between successive RPM at each site is different from the KIWA recommended frequency of 12 months. D ifferent frequencies are being trialled t0 d etermine the optimal frequency for an unfiltered system. Yarra Valley Water intends to develop an


technical features

optimum RPM measurement frequency for each of its water quality zone based on the data collected in the fi rst 12 months of its current mains cleaning program. The schematic ofYarra Valley Water's RPM equipment is shown in Figure 4. A typical RPM resu lt is shown in Figure 5 for before and after mains cleaning. The data will also be analysed spatially to identify regions of significant sed iment accumulation within the distribution system.

• rt

Sydney Water's RPM Equipment Due to the enforcement of water restrictions, Syd ney Water ceased its programmed mains cleani ng program in 2002, which included borh flushing and swabbi ng. In 2005, Syd ney Water developed a co mpact RPM unit to proacrively determine when to clean mains. Due to Sydney's continued water restrictions, the equipment is curren tly being trialled at Yarra Valley Water and Central Highlands Water to assess its suitability for different system conditions. The equipment co nsists of continuous flow and rurbidity meters, data loggers and an on-sire data display panel. This trial is expected to identify any further modifications or improvements necessary to ensure rhe user frie ndliness and robustness of the equipment.

Figure 6. Enhanced PSM in EPANET - Source: Yarra Valley Water Donca ster Model. 30 Surface Plot

Particle Sediment Modelling (PSM) C RC engaged CSl RO to develop a computer simulation model to predict the movement of particles in the distribution system, within its research project 'Particles in the Distribu tion System'. The details of the theory, development and applicatio n of the Particle Simulation Model (PS M) were published in the AWA Water Journal in December 2004 Qayaratne et al., 2004) . The original PSM was a basic sed iment movement model able to predi ct gravitational seeding and flow induced re-suspension of particulate material in the water supply system. T he accuracy of th is prediction depends on the accuracy of the hydraulic model. Sediment accumulation and re-suspension in pipes are dependent on the three experimentally derived flow velocities, which have bee n incorporated into rhe model. A sediment mass balance is undertaken ar each pipe ar each individual time step in the sim ulation. Th e PSM has recently been trialled in the Netherlands for a water supply system (Vos, 2005). Data from the hydraulic model (ALEID hydraulic modelling software) were easily converted to input files for PSM. T he sediment mass at various points in the distribution was measured using Time Integrated Large Volume Sampling (TILVS) equipment (see later in this article). Particles were reseed in a pipe test rig ro establish rhe key model input parameters of sedimentation, deposition and re-suspension velocities. The results of rhe PSM calculatio ns over a period of I 2 months indicated chat the areas of particle accumulation were consistent with the assess men r of rhe operators of chis system. The PSM accurately predicted rhe mai ns rhar required frequent cleaning. The trial demonstrated chat the PSM can be applied to rhe Durch systems despite the lower particle accumulation associated with their high degree of rrearmenr co mpared to Melbourne. The sediment loading in the system ranged from 0.01 mg/L to 0.2mg/L indicating relatively long period of sediment build-up. The CRC research project, 'Consolidation of Modelling Tools', developed a common platform where current and future models can be operated from one application. The PSM has now been incorporated into this platform. The ability to predict particle movement wirh PSM was furth er enhanced after the inclusion of rhe theory of particle adhesion/removal from the pipe wall. The

• •

03277 03 02 01

D O

Figure 6a. Regions of Particle Accumulation. PSM has been converted to the commonly available EPANET platform (Figure 6).

PSM Case Studies Two case srudies will be undertaken to trial rhe en hanced EPANET version of the PSM. T he proposed Yarra Valley Water case study will involve the RPM data collection from irs Doncaster water quali ty zone, at twenty selected sites. Validation of the PSM will be undertaken by correlati ng the model outputs wirh RPM results from the field, customer complaints, and pipe velocity data from rhe hydraulic model H 20MAP. The correlation analysis will produce charrs (Figure 6a) to identify regions of parcicle accumulation.

Particle Counting Currently in the Netherlands, continuous turbidity monitoring in the distribution network is used to analyse the movement of particles in the network and the associated discolouration risk (Vreeburg et al., 2004). However, turbidity measurements in combination with particle counting provide additional data to better manage discolouration risk. Particle counters are already used in water treatment to detect fibre breakage of membranes (Glucina et al., 1997) and to evaluate treatment efficiency (O'Leary et al., 2003). In a study of the transport of particles within the distribution system of the Amsterdam Water Supply, conducted by

Journal of the Australian Water Association

Water

FEBRUARY 2007 147


technical features UI .... • •. •.

water supply Volume of particles in Leiduin transportation system

S0.000

, - -;::::::::i:===:::r:::==::::;-r-----,-----,--T-,---,

~

~ 40,000

"'e

~ Cl>

E ::,

g

"' Leiduin ...... Haarlemmermttr "T Amstelveense North

30.000 20,000

Cl>

~

10.000

&. 28/07

30/07

01/08

03/08

05/08

07/08

09/08

11/08

Figure 7. Particle concentrati on in the Amsterdam Water supply system. Haarlemmermeer is 15km and Amstelveenseweg North is 30 km downstream of the treatment plant. Source: Verberk el al., 2006. Lisa Hamilton and Kelly O'Halloran (Griffth University), multiple particle counters were used (Verberk et al., 2006). This research was undertaken within the research exchange program between the CRC and KIWA. The results of the study show that by installing multiple particle counters simultaneously at strategic locations in the distribution netwo rk it is possible ro obse rve cha nges in particle size, number and concentrations (see Figure 7). This information can then be used to relate changes in particle numbers to processes like deposition and re-suspension of loose material. Furthermore, ir is possible ro compare rhe sediment loading of separate distribution systems and relate the differences between systems to the preceding treatment processes and rhe hydraulic condi tions in the network. Another application is the use of particl e coun t measurements to determine residence rimes. Whi le the total particle number and turbidity generally followed a similar pattern, it was found that the particle counters were more sensitive to cha nges in water quality. This sensitivity enabled the calculation of residence rime between different sampling locations in the distribution network. Particle counting assists in understanding changes in particle size and volume within che disrribmion system. However, particle counters do nor provide information about rhe composition of rhe particles or co llect particles for later analysis.

Time Integrated Large Volume Sampling (TILVS) TILVS is a new tool in distribution water quality research and is very useful to preconcentrate particulate material to characterise the co mposition of particles. Th is information can be related back to the processes in volved in the change of water qual ity in the distribution network. The combination of particle counting and

148

FEBRUARY 2007

Water

TILVS enables conclusions on the composition , origin and changes in rime and place of particulate load in the distribution system. There is sti ll some opti misation required with the operation of TILVS. However, it is a simpl er method and combined with simultaneously performed particle counting ir will assist in understan ding rhe processes lead ing to discolouration events in the distribu tion network. This approach will provide valuable data for the prioritisation of distribution water quality research. A number of water util ities in Australia have expressed interest in using TILVS in combination with particle counting to understand the water quality processes in their distribution systems. TILVS is capable of measuring rhe composition of suspended particles in drinking water distribution systems. T he TILVS concept was developed in 2005 by researchers from rhe Delft University, Netherlands, and Griffith University, Australia (Verberk et al., 2006). The particle loading in the distribution system is generally low and therefore rhe standard procedures to measure total suspended solids (TSS) and volatile suspended so lids (VSS) cannot be used. A large volume of water has to be filtered to collect sufficient mass on the filter paper, while a rapid clogging of the fil ter paper occurs due to the large amount of small particles. With TILVS water is fil tered under pressure for particle analysis using an experimental on-li ne sampling set-up consisting of a pump, a water weir and a stainless steel filter unit (Figure 8). The pump del ivered a constant flow of water to the filter. The samples are co llected on 0.45 µm cellulose acetate filters. Filters are analysed gravimetri cally for TSS and VSS . Inorganic analysis was undertaken by ICP-MS to analyse fo r potassium, magnesium, calci um , silica, manganese, aluminium, copper, barium and zin c. Iron was analysed by flame-AAS .

Journal of the Australian Water Association

Two TILVS units are always deployed at a sampling location in parallel and run in conjunction with a particle counter (Figure 8-right). One sample is analysed fo r TSS and elemental analysis while the second sample is analysed for TSS and VSS. The initial experiments with TILVS were carried out in rhe distribution system of Amsterdam, co mplementaiy to rhe ea rlier described particle counting. Ar the rreacmenr location rhe TSS was much lower than in the distribution system. An increase in particulate mass by a facto r of five was observed. Furthermore, the results of che elemental analysis of sedi ment crapped on the fil ters demonstrated a large increase in element concentrations within che distribution system. In particular, che amoun t of particulate iron increased from 0.13 µg/L at che treatment location to 5.3 µg/L at rhe measuring location 30 kilometres away from the treatment (Amstelveenseweg). This 40-fold increase is caused by re-suspension of old sediment or post-flocculation of colloidal iron. Volatile suspended solids (VSS - organic matter) cou ld not be measured at the Leiduin treatment plant due to the low mass retained on the filters . Ac Amstelveenseweg, the VSS ranged from 15-55% of the total mass. From the elemental inorganic components and the VSS, a mass balance of che composition of suspended solids was calculated. Undetermined components account for only 4 to 24% of the deposits (Verberk et al., 2006)

Conclusions In Australia and the Netherlands, there is a growi ng mutual interest in water qual ity research in che distribution network, particularly in the area of managing discolouration risk. Research programs in both co untries focus on understanding the water quality processes in the discribucion system . Although the treatment methods in both countries are quire different, water quality tools developed have been exchanged and trialled successfully. The water quali ty tools presented in this paper (Conceptual Model, RPM, PSM, particle counting & T ILVS) will be valuab le in understanding processes leading to discolouration and to reduce customer complaints. T he conceptual model is a platform to pinpoint possible problem/risk areas and develop micigarion strategies such as mains cleaning. The application of RPM to determine cleaning frequency has become more relevant in Australia especially during drought conditions. Pred iction of water mains which have a greater potential of particle accumulation, using rhe PSM model, will improve the effectiveness of


Transport line

1)ci Detector

TSS VSS

Particle counting Elemental analysis

Figure 8. TILVS installation. Source: Verberk el a/., 2006. cleaning programs and reduce loss of water. Characterisation of particles using particle cou nts and TILVS wil l assist in determining the source of the discolouration. The recent exchange of research students and research staff betwee n the CRC and KIWA has proven successful in the application of water quality cools developed in Australia and the Netherlands co ach ieve common objectives. This exchange program was valuable in bridging the gaps in awareness and knowledge on broader water quality issues associated with water distribution systems. It is envisaged chat chis collaborative research effort wi ll continue in che coming years with furthe r exchange of researchers and a wider participation of global water research organisations including the Global Water Research Coali tion and the American Water Works Association Research Foundation. Acknowledgments

T he authors would like co acknowledge Anke Grefte and Jan-Hendrik Vos from Delft University of Technology for their valuable contributions to chis collaborative effo rt. The Authors

Jasper Verberk is an Assistant Professor in dri nking water supply at Delft University of T echnology and is currenrly working for 1.5 years at che CRC. Corinna Doolan is che Co-Deputy Distribution Program Leader of C RC and Sydney Water Project Manager for the CRC 's D iscoloured Water Project and an Environmental Scientist at Sydney Water Corporation. Asoka Jayaratne is the CoProject Leader of the CR.C's Particles in Distribution Project and a Senior Planning Engineer at Yarra Valley Water. Dr Peter Teasdale is a Senior Lecturer at Griffith University and Project Leader of the CRC 's Discoloured Water Project. Jan Vreeburg works as Senior Researcher for Kiwa Water Research and Delft University of Technology. Kelly O'Halloran was a Senior

Research Assistant at Griffith Univers ity on the CR.C's fo r the Disco loured Water Project, including a 4-month project at Delft University of Technology. Lisa Hamilton was a Senior Research Assistant at Griffith Uni versity on the CRC for the Discoloured Water Project, including a 4month project at Delft University of Technology. Dammika Vitanage is che Distribution Program Leader of the CRC and Program Manager, Science and Technology at Sydney Water. Contact author: CO RIN NA.DOOLAN@ sydneywater.com.au literature Anroun, E. N., Dyksen, J.E. and Hiltebrand, D. ( 1999) 'Unidirectional flu shing: A powerful tool' Journal American Water Works Association, 91 , n 7, 1999, p 62-71. Glucina K., Do-Quang Z., La1ne J.M. ( 1997). Assessment of a particle counting method for hollow fibre membrane inregriry. Desalination, 113, 2-3, 183-187. Jayararne A., Ryan G., Grainger C., Wu J., NouiMehidi M.N. (2004) . Modelling of particles in water supply systems. Water, journal ofthe Australian Water Association, 3 1, 8, 30-36. O'Leary K.C. , Eis nor J.D., Gagnon G.A. (2003). Examination of plant performance and fi lter ripening with particle counters at full-scale water treannenr planrs. Environmental technology, 24, l-9. Van Dijk J.C., van der Kooij D . (2005). Water Qualiry 21 research programme for water supplies in t he Nerherlands. Water Science and Technology: Water Supply, 4, 5-6, 181-188. Verberk J.Q.J.C., Hamilton L.A., O'Halloran, K. J., Horst W . van der, Vreeburg J. (2006). Analysis of particle numbers, size and composition in drinking water transportation pipelines: Results of on-line measurements. Water Science and Technology: Water Supply, 6, 4, 35-43. VreeburgJ .H. G., Schaap, P.G, Dijk, J. C. van (2004) Measuring Discolourat ion Risk: Resuspension Potential Method: Leading Edge Technology, Prague, !WA. Vos J.H. (2005). The application of sediment transport models to predict discoloured water evenrs. MSc-thesis, Delft Universiry of Technology. Water Services Association Ausrralia Facts 2005.

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FEBRUARY 2007 149


WATER GOVERNANCE REGIMES IN AUSTRALIA: IMPLEMENTING THE NATIONAL WATER INITIATIVE J M McKay Abstract Governance is the p rocess of decision making in the community involving both formal and informal actors at all levels. Governmen t is just one of the formal actors in governance. The inscicucions and organisations it creates by laws and regulations are the formal actors in che process of extracting, discribucing and using water. There are of course many informal institutions as well such as customs of the society with respect co water use and allocation and in relation co enforcement of the law. After the Council of Australian Government reforms in 1994 there are many laws creating many types of organisations co extract, discribuce and use water in each Scace. This paper reports on work co examine the formal legal processes. The work establ ished chat there are now 14 different types of corporate organisations supplying water in Australia. These formal organisations and the informal institutions have d ifferent responses co the formal water law and po licy changes. The responses of the formal organisations and informal institutions are instrumental co the success of the new water law and policy reforms under the National Water Initiative. T he paper reports on some results from a telephone interview with 183 of the Chief Executive Officers of the largest water supply businesses. T he results presented

Only one-third of water supply chief executive officers surveyed across the nation are confident that their companies or enterprises can achieve sustainable water management. 150 FEBRUARY 2007

water

FORMAL Orguluulon (L 11w of Forn1111tion)

INFORMAL Poltcy ScialMor.s

INFORMAL Sac1ors of the community

wllllns/unwilllns to adopt ,,.w water lows

FORMAL

Organisations FORMAL l.1ws

Wator Supply Buslnossos & Catchment Management Authorities

INFORMAL

Gtntr•l St111r Laws Fin1nri1I Rtportlng Envlronmtnt• I Rrpor1lng, C11tC'hmrn1 Mu1grmrn1 Bo1nb

INFORMAL

Fcdcrol 'Policy to Cltans• Stat• law, 1mdcr M,,/1

FORMAL Statr Wi ltr L IIW.!I M11nd• ting ESD illltr a/111

w'lllfn,n•u al State to enforce off os,,.cts of water lows la crlmlnol offcc,tns for water tit.ft

IC ,\lcK•y, 2006

Figure l. Representation of the institutions, formal and informal, impacting on water supply business organisations.

here look at their responses co the new water policies in particular evaluating the effort put inco ESD by the CEOs, the difficulty in pleasing the regulators( both environment and price), the amount of information they have about water policy and whether chey cruse che Scace government.

Introduction Governance, not a true scarcity of water, is che core of the world water crisis according co che UN 2nd World Water Development Report released in early 2006. The Australian Government has initiated che two waves of CoAG reforms co alter che governance structures co achieve efficient and more productive water use. This is seen as increasingly important over the coming decades as water issues impact upon the continued stability of Australia's rural sector, urban communities and the nation's economic well-being. The Government is determined co continue increasing efficiency in water use and implementing reforms co achieve chis national objective. (DAFF, 2006.)

Journal of the Australian Water Association

Water Governance in Australian Institutions and Organisations Governance always looks at how power is exercised in the management of economic and social resources for the society, also how co mediate disputes between members. Often governance is about creating the cond i cions fo r ordered rules and collective action. Internacional literature has eight characterist ics in common for good governance -participatory, consensus orientated, accountable, transparent, responsive, effective and efficient, equitable and inclusive and fo llowing che rule of law. (UNDP 2001, Global Water Partnership) Australian Standard 8000 defines it ... "as being concerned wich improving the performance of companies for che benefit of shareholders, stakeholders and economic growth. le focuses on che conduce of and relationships between the board of the directors, managers and company shareholders." Governance is considered in any society ac any point of time as the sum of formal and informal and organisations. In a sector such


Table 1. Corporate Governance legal types of major Water supply businesses in each State.

Loco! Government Regional Council (LGRC) Shire Council (LGSC) City/Town Counci l (LGCC) 2 Local Government Owned Corporations (LGOC) Joint Local Government Organisation ULGG) 3 Water Boards {Includes Rural Water & Drainage Boards) (WB) Government Departments Licenser (GD) Government Owned Corporation (GOC) Statutory Bodies (SB) Corporations Law Companies (CLC) Irrigation Trusts (IT) Undetermined

4

Hybrid - (SB/CLC)5 Hybrid - (IT/ CLC)6 Total

ACT

NSW 1

NT

QLD

SA

TAS

VIC

WA

Total

0 0 0 0 0

2 46 0 14 5

0 0 0 0 0

0 92 15 4 1

0 0 0 0 0

0 17 5 0 3

0 0 0 0 0

0 14 0 0 0

2 169 20 18 9

0 0 1 0 0 0 0 0 0

0 0 5 0 3 2 0

0 0

0

0 0 1 0 2 4 0 0 0 7

0 2 0 0 0 0 2 0 0

0 0 6 1B 0 0 0 0 0

2 0 1 0

2 3 16 18 7

0 4 0 0

6 6

29

24

22

278

0 0 0 0 0 0

74. 797

1 0 1 0 0 0 0

115

1. NSW councils that generate turnover of> $2m ore classified by the Notional Competition Policy and Local Government Act 1993 {NSW) as category 1 businesses. If< $2m then category 2. Category I businesses ore sub;ect to more stringent reporting/auditing requirements and must be privatised corporations. In effect, category 1's ore/ may be semi autonomous subsidiaries or completely autonomous privatised corporations. Thus, the level of turnover is crucial to the character of the entity and its classification.

2. Includes Local Government Town Councils and Local Government City Councils. 3. Includes Organisations that ore owned by a collective of LGAs and organisations owned by a collective of LGAs with Stole Government. 4. Typology hos not been determined due to insufficient materials to make a definitive assessment. 5. West Corurgon Irrigation apparently exists as both a Statutory Body and a Corporations Low Company. 6. Western Murray Irrigation Ltd is identified as an Irrigation Trust within legislation but is structured and operating as a Corporations Low Company. 7. NSW hod extensive council mergers and redrafting of Council boundaries during the period that this research examines. As such, the material collected reflects the rapidly shifting face of the NSW Water Industry. At the beginning of the researched period, there were 79 distinct WSBs, within the year; however, amalgamations hod reduced this number to 74. as water, governance allows di fferent arrangemen ts of che inscicucions and organisations co be mapped and exam ined. The formal coercive ob ligations imposed by che inscirncion of che law in Australia requi re all organisat ions co ach ieve ESD. Originally chis was done through a variety of Scace-based Aces because of section 100 and che paramoun ccy of Scace law over water for conservation (impound ing) and irrigation (McKay 2005). T he Scares then ceased co co-operate on water, devised introspective Scace policies and formed d ifferent institutions and organisations to d iscribuce water for che sole purpose of economic development. Over rime bur especially si nee the early I 990s the aim s of che Scace schemes b roadened co encompass ocher goals and include environmental and social sustainability as pares of modern water policies. This was done by che adoption of ESD inco che water laws and policies and by institutional and organisational adoption of ESD. In 1990 there were more chan 100 statutes which required ESD in Australia ac local Scare and federal level. (Stein 2000) but now there would be over 400. There are differences in che coverage of the ESD definitions both

withi n statures in each Scare and between che Scates. (M cKay 2006, Table 2) . Whilst che overarching goals are set federally in che NWI, the means to ach ieve chem is left co th e Scares which, as in all federatio ns, chose co do things differently. This can create a laboratory of policy experiments which offer learni ng opportunities bu r also can create confusion. (Brand ies 1932) Previous international research has d escribed how the form of organisatio n has a great in fl uence on achievements of any policy (North 1990, Young 2000). The imposition of laws co achieve ESD is an outcom e of societal pressures, bio-diversiry catastrophes and drought. Laws have been imposed on the organ isations in order for the organisations co maintain their legitimacy wich some influential sectors of modern Australian society. (Di Maggio and Powell 1983). Thus the policy co achieve ESD is coercive on each organ isation as it is pare of the law of each Scace. Governance d erives from society and is made up of formal and informal institutions and organisations. Such actors reflect local political, cul tural and administrative traditions and are represented in Figure 1 in relation to Water

Supply businesses. There are institutions such as the general law which are coercive i.e. structures of property rights co water and informal aspects such as the willingness of perso n entrusted co enforce the law such as local police to actually use their powers. All of these have an impact on the eventual performance of the organisations Figure 1 expresses che arrangements between the formal and informal insri rnrion s and the water supply business organisat ions and Catchment Management Boards (Natu ral Resources Management Bo ards in South Australia). There is interplay within and between all these organisations and the institutio ns.

Typology of Australian Water Supply Businesses In the past in Australia, the main organisations were p ublic sector bur si nce che 1994 Council of Australian Government Reforms the organisations involve more p rivate sector roles in all aspects and place government in a regulatory role on price and environmental impacts. Governance arrangements fo r water in A ustralia are complex with over 14 different types of legal forms of water

Journal of the Australian Water Association

Water

FEBRUARY 2007 151


technical features

The CEOs were fi rst supply businesses (Table Table 2. Relative ran king of w idth of ESD definition in fou r Australia n contacted to make a time 1). The mosaic of different States and through MDBC template leg islation in each State. to have 30 minutes free to fo rms each have multiple do the interview. The reporting arrangements as Rank of ESD definition width interviews rook place determined by the relevant l (Equal) MDBC Template* between September 2005 Aces. The different Aces l (Equal) SA (downstream) l 0% in MDB area and January 2006 and were also create an informal conducted by 3 trained Qld (upstream) 25% in MDB a rea 2 institution around what professional interviewers at could be called 'reporting NSW (upstream) 90% in MDBC area 3 Ehrenberg Bass Institute at culture'. For example, the 4 Vic (midstream) 60% in MDB area University of South reporting cultures for *Legislation inserted into State law of Queensland, New South Wales, Vic, SA. Australia. The respondents organisations empowered were all sent a project under a Local Government informatio n sheet and advised chat their at the macro scare level fi nancially but also a Act are very different from chose existing for huge role with respect co the achievements responses were confidential. There were a body reporting to the Australian Securities of NW!. These State bodies and others such over 100 questions and the average time for and Investment Commission (ASIC). interview was 27 minutes with no-one as Catchment Management Boards are the At the ground level, diffe rent legal fo rms fo r stopping the interview. Respondents front line implementers ofNWI. adjacent water supply businesses make coreported chat they liked the survey as they operation and data sharing more difficult. The aim was to determine if the had a chance to explore issues and report on Furthermore, the culture of the organisation organisational type was a factor in attitudes issues that concerned them. T he results for guides its implementation of the NWJ in a to selected NWJ reforms and hence whether all but the first questions are reported by profound way and its understanding of implementation of selected NWI goals was Scace (as there is only a single authority in sustainability and the procedures it can more or less likely in different organisation che ACT and NT , their responses will not place in its strategic planning framework to types. This process has been defined as be published to protect confidentiality) and implement Environmentally Sustainable Evaluation of law and policy by implementers corporate governance type . Development (ESD). The fundamental (McKay 2006) is a strategic way to co nduce The respo ndents were selected to represent premise of ESD is that economic processes of law reform. In Australia, the che types of organisations listed in T able 2. development muse be balanced against the processes of law reform rarely cake chis The CEOs were distributed as such; 86 out protection of biological diversity, the systematic approach often responding co of 115 from Queensland, 38 from 78 in promotion of equity within and between acute crises (Opeskin 2001) NSW, 24 fro m 29 in Tasmania, 13 from 24 generations, and che mai ntenance of The goals selected were aimed at evaluating in Victoria, 20 fro m 22 in WA and che only essential ecological processes The culcure is che effort put into ESD by the CEOs, their one from each of the ACT and NT. T he often guided by the way the organisation is ability co please the regulators( environment distribution by typology type reflected the ru n, e.g. some water supply bodies are run and price), the amount of information they proportions with local government by grower/users elected from regions in the have about water policy and if they cruse predominating. In the charcs below the area, yet ochers (most of the big urban and their Scace government. results for the two single authorities in the rural bodies) have board members An earlier part of chis study assessed the Northern Territory and Australian Capital appointed by the Scace Government content of an nual reports for all water Territory have been omitted. (McKay 2005) Local governments which supply bodies under 10 themes including supply much water have elected officials and All the sample CEOs were male and all had ESD actions. T he results suggested chat che their region may cover urban and ru ral been in th e job fo r at least 6 months. Over 24 Victorian util ities (all single mission areas. 50% has been in the same organisation for water suppliers) reported the most ESD 5 years or less, with 15% there for between This typology was created from the Annual actions. The vase majori cy of other water 6 months and 1 year, 20 % for between 1 Reports of the bod ies fo r 2003/4, classifying supply businesses are empowered by a Local and 2 years and 14% fo r 5 years or less. Juse chem according co legal type. T he decision Government Ace, and have water as only over one third 34% had been CEO for was made co look only at major water one of m any missions. (Gray and McKay between 5 and 11 years i.e. post CoAG supply businesses i.e. chose supplying more 2006) 1994 and 22% for greater than eleven years than 250 customers. There was very little which means pre and pose CoAG 1994. ocher research co guide chis process at the Evaluation of selected NWI policies However it was found chat the time of rime and subsequent data confirms che by CEOs service was not significantly related to the Victorian fig ures and suggests chat there are answers to the questions. The method was co identify the relevant 125 bodies in Queensland and 120 in NSW policies and laws from Scace and fede ral in 2005 (Australian Government 2006). CEOs and ESD implementation The forms of the bodies listed here exclude instruments and from conversations with What does sustainable development really the small mining company or indigenous CEOs and ochers. After the issues were mean? Sustai nable development as a water supply schemes which exist under identified the next seep was design an concept is notable fo r its lack of consistency special aces. instrument co evaluate (on an eleven point in its incerprecacion (Sharachchandra 1991). scale) perceptions, understandings and Table 1 shows chat Government at Scace le daces from 1987 (Brundcland 1987) attitudes to the policies and laws by the key and local level still has a major role in the W hilst on che political level the face chat ic actors. As che respondents were water industry and the Scace-owned is so broad is appealing but chat is also its sophisticated, the interview schedule was corporations contribute significant amounts weakness as the problems of poverty, long with 100 questions and respondents to reven ue of the Scace and che local environ mental degradation, econom ic were contemporaneously emailed lists of governments in the fo rms of dividends. growth and participation are not well Hence these bodies have an important role items to rank order. 152 FEBRUARY 2007

Water

Journal of the Australian Water Association


technical features 8

sustainability articulated. Such a lack of clarity may hamper the debate and certainly the implementation.

1400

1000

Despite the above, each State has defined ESD in a number of acts, totall ing about 400 in the whole nation. These acts apply to all actio ns of che Water Supp ly businesses and other institutions and organisatio ns. The defin itions of each of these spans over many sections of each of the Acts/ The rules of interpretation of Acts (in each Stace) are also d ifferent. Table 2 ranks the width of the various definitions of ESD.

400

Decision making processes shou ld effectively integrate both long and shore term economi c, environmental,social and equity considerations, in seven principles:

""

1200

In Australia, Intergovernmental agreements on the environment imposed the 7 principles of ESD (National Strategy on Eco logically Sustainable Development 1992, 1993)

The fundamenta l premise of ES D is chat econom ic development must be balanced against the protection of biological diversity, the prom otion of equ ity within and between generations, and the maintenance of essential ecological processes. The Co mmonwealth Governmenr working groups on ESD d rafted these principles to guide ESD in 1992 (Hamilton and Throsby 1998). Namely:

I Z!l

800

600

200

Scltntlfk

Dlvtrtt

lrttmltfon..

Otd1lon

Ctrllmty

Economy

Competh'tnns

M-'c:lng

~ DlfflcuitylnAchltvlng ESO Prindpln

D DtgrM dEffortExptndtd lnAchltVlng ESOPTlnc'P*

~1&3aO~r;liC4F :lQ)l!I

O McK.,,1006

Figure 2. Effort and difficulty in achieving ESD. collective chi nking of governments in the formu lation of contemporary water policy.

few of these. The votes were then tallied as shown in the figures.

The first two questions reported here were emailed to the respondents so they could see the full text and they were asked to race each one from I not at all difficult to IO extremely difficult. In the second questio n, they were asked to race chem according to the effort they have pu t in from 1 feast effort to 10 most effort. In all the questions # 11 was 'don 't know and refused' but there were very

Responses to the firs t question ind icate that the CEOs thought that it was most d ifficu lt to achieve global dimensions and lease difficult to achieve broad community involvement. In relation to effort, most effort went into 3 dimensions broad commu nity involvement, cost effective policies and integrated decision making processes.

C&SBRAND AUSTRALIAN FILTER COAL FOR DEEP BED COARSE DUAL MEDIA FILTRATION

2 . T he global d imension of environmental impacts of actions should be recognised and considered, 3. T he n eed to develop a strong, growing and diversifi ed economy which can enhance the capacity for environmental protection should be recognised,

"More UFRVs for your money, and better quality water"

4 . The need to enhance and maintain international co mpetitiveness in an environmentally sou nd manner should be recognised,

6. Cost effective and flexible policy instruments should be adopted; and

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1. Lack of full scientific certainty should not be used as a reason for postpon ing measures to prevent environmental degradation (the Precaut ionary Principle) ,

5. Decision making p rocesses should effectively integrate both long and shore term economic, environmental social and equity consideration s,

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7. Broad community involvement should be facilitated.

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This statement has been accepted by CoAG and reflects that econom ic efficiency is not the main goal of water institutions bur rather that there is a n eed to achieve ESD and balan ce between the social, economic, and the environmental needs. These seven principles have accordingly gu ided che

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Journal of the Australian Water Association

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FEBRUARY 2007 153


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sustainability I n relation to the transparency of the ESD process Figu re 3 indicates that most o rganisations have a neutral view. All had heard of the process. H ence they were neutral at to whether the process in their State is transparent. T he Water Boards perceive the p rocess as transparen t. Local government are clearly of the neutral view. In relation to ability to achieve ESD, (Figure 4) the lo cal governmen ts were most likely to be neutral; W ater Boards and Government O wned Corporations were more likely to agree that they could achieve it. In relation to work on local government and participation in Regional NRM Plan development it was reported that most councils were not active because of a lack of resources with 56 per cent of councils highlighting a lack of hu man or financial resources to effectively participate. Only 3 1 per cent of cou ncils believe they have a good or comprehensive capacity to develop and implement the regional plans. (Australian Local Government Association 200 5)

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T he CEOs also reported low levels of trust in relation to the relevan t State government. T here was also a m assive variation between

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Question 12 asked whether they felt they were kept info rmed by their State Government: the results are shown in Figure 7. The results differed marked ly between the States. Water supply businesses in Victoria were most likely to trust and the lowest trust level was fo und in the N SW A study in Queensland of stakeholders in small catch ment fou nd that there was little t rust of the State government over NRM. (Rickson 200 6)

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Social capital theory in relatio n to environmental matters has often focussed on understanding how various actors interact with one ano ther in relation to the water policy environment. By understanding the social capital of d ifferent environmental actors, fo r example water users and water policy implementers, we can understand why some policies end up being implemented and why noble aims often fai l.

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The questions asked aimed at findin g which o f the regulators was the more d ifficult to please. Figures 5 and 6 show that the environmental regulator is seen as harder to please in New South Wales and also for local governments. T he p rice regulator is seen as hardest in Victoria and by Statutory Boards.

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Journal of the Australian Water Association

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technical features

Corporate governance types as well with Statutory Boards and Government-owned corporations most trusting and local government least.

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In support of the above the CEOs also reported that they don't generally feel nested in a mutually suppo rtive policy environment except in V ictoria and this related directly to the corporate governance type of Government owned corporations, as shown in Figure 8.

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Summary and Conclusions There have been massive reforms of Stace water laws, policies, institutions and organisations in Australia over the last 12 years. These reforms have created many new bodies and complecely restructured ownership of assets and management in all Water Supply businesses. The reforms aim to achieve ESD but each State defined it differently and has implemented it in different ways. T here are 14 types of water supply businesses in Australia with N SW having 9 types spread over 79 major water supply businesses. The different types of legal organisation means that there are different organisational cultures processes and regimes to satisfy from coercive institutions such as the plethora of laws within and between States. Most reforms require partnerships between Commonwealth and State agencies and also partnerships between different secto rs of the comm unity to achieve ESD implementation, as defined by the relevant acts. This paper has shown chat rhe ESD policy implementers, the CEOs, have made considerable effort. However, the partnerships between sectors of rhe community and between them and Seate governments are impaired by a lack of trust and a perception chat rhe water policies are not mutually supportive. M any of them are also puzzled as to how to achieve ESD and with acute differences between the States in definitions there is a limi ted scope for chem to learn from each ocher. Notably the environmental regulator is seen as harder to please in New South Wales and also for local governments. T he price regulator is seen as hardest in Victoria and by Statutory Boards.

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Commerce and benefited from feedback given by the respondents and also from comments by George Warne (NSW), Geoff Parish (SA), Tony Thompson (SA) and the opportunity to present some of this to meetings organised by ACIAR and AN CID.

Ocher support was made available from J olyon Burnett, Irrigation Association of Australia, and Stephen Mills, Australian National Committee on Irrigation and Drainage and Chris Davis of the Australian Water Association.

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Acknowledgments This work was conducted as part of a proj ect for the CRC Irrigation Futures. I r was supported in kind by members of the CRC especially Matthew Durack, G len Starkey, John Bourne, Eddie Parr, Peter Smith, John Williams, and Bernadette Zerba. The project was also supported by rhe University of South Australia, School of

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technical features refereed paper

sustainability The projecr employed Adam Gray who did a great job in liaising with many organisations and drawing these charts. Michael Griffin and Fiona Partington checked rhe rypology by reference ro rhe Annual Reporcs of rhe water supply busin esses. Kirsty W illis co-ordinated the interviewing with good humour desp ite this being one of rhe longes r and rechnically challenging surveys in rhe experience of rhe Ehrenberg-Bass Research Insrirure. Rex Jones and Kathryn Pickering provi ded much support in the fi nancial managemenr and other members of the Centre collected articles and checked the res ulrs especially Ganesh Keremane, Anna H urlimann, Arthur Spassis and D iwakara Halanaik.

The Author

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Jennifer Mackay is Professo r of Business Law, Schoo l of Law, University of Sourh Ausrralia. Email: jennife r.mckay@unisa.edu. au

References Australian Govern ment 2006 A disc ussion paper on the role of rhe Private Sector in the supply of water and W aste water services, D epa rt ment of Prime Minister a nd C abinet, August Aust ralian local Governm ent Association 2005 N RM Survey of Local G overnment 2004-5, Angela Shepherd http:/ /www.alga.asn.au/ policy.environ men r. nrm/survey Austra lian Standard 8000 2003 Corporate Social respons ibil ity as amended 2004, www.sranda rds.co m.au Aust ralian Water Resource Assessme nt 2000 surface and groundwater availabi lity and qual ity, a report of the N at io nal Land and Water Resources Audit (Aud it). Brandeis J UST ICE (1932) New State Ice Co. v Liebmann 285 US 262 AT 3 11 Brund rland Report ( 1987) Our Common Fut11re,

Report of the UN World Commission on Environment a11d Development, Oxford Un iversity Press, Oxford D aff (2002/03) Department of Agriculture Fisheries a nd Forestry National G overnmenr. h rrp://www.daffa.gov.au/ abou r/ annualreport/ 02-03/appendices/app6 Di Maggio and Powell 1983 ' The iron cage revisited: l nsrimrio nal iso morph ism and collect ive rationality in orga nisational fi elds, American Sociological Review, vol 48, no 2, pp l 47- 160 G lo bal Water Parrnership web s ite ,vww.gwpforum.org Gray A and JM McKay Are Utility a ttitudes to the environment shaped by corporate governance? Assessing the evidence from Australian U tility repo rts, Water Utility Management fntern11tio1111I, Vol l ppS- l l. H arris, S and D. T hrosby 1997 The ES D Process: Background, imple mencation and aftermath, in H amilton C and D Th ros by (eds) The ESD Process evaluating a Policy Experiment, p 1-2 1, Academy of Social

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Figure 8. Mutually supportive policy environment. Sciences a nd G radua te Progra m in Public Policy Australian National U niversity W orksho p, ANU, Published by the Academ y of Social Sciences in Australia McKay J M 2005 W ater Ins ti tutional reforms in Auscralia in Special issue of Water Policy

Water lnstiw tional refonns; Theory and practice, p 35-53 . Mc Kay 2006 Issues fo r Ceo's ofWarer U tilities with the implemen carion of Australia n W ate r Laws, journnl of Contempomry Water Research 1111d Ed11c11tion, vol 135, pp 120- 137. Mc Kay 2007 The legal frnmework ofAustralinn water in C rase L (ED ) Water Resources in Auscralia, Issues in Wate r Policies Series, series editor A Dinar, Reso urces for the Futu re, www.RF FPress.org/warer National Strategy on ecologically sustainable developmenr 1992, 1993 Australian Government Publishing service National W a ter lniriative web sire w ww.nwc.gov .au

North, D. ( 1990) . Institutions, i nstitutional

Change nnd Economic Pe1formance, C ambridge Unive rsity Press, Cam bridge, Massachuserrs.

Journal of the Australian Water Association

O peskin B ( 200 I) Law reform in a federal system, Reform journal ofthe Australian law reform Commission, issue 78, p29-34 and 72 . Powell, J. ( 1999). Vic to ria, in Broughton, W. (ed.), A Century of Water Resources Development in Austmlia,The Institution of Engineers Australia, Sydney. Rickson S (2006) Linking the social with the environm ental; Identifying C ommunity capacity in the South East Queensla nd Western C atchme nts G roup, in Whelan J 2006 ( Ed) Parcnersh ip based social research for sustainable natural resource management in Queensland. N ational Action Plan for Salinity a nd W ater Quality Salerh, R. M. & D inar, A. (2004) . The

lnstitutionnl Economics of Water: 11 crosscountry analysis ofinstitutions a11d pe,formance, C hel tenham, UK: Edward Elgar Publishing Pvr. Sha rachc handra I 99 l , Sustainable D evelopment: A critical Review, World Development vol 19, no 6. p 607-62 1 UN 2nd W orld Water Development Repo rt 2006 Young M (2000) The lnstirutional D ime nsions of Environmental Cha nge fir interplay and scale MIT Press.

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Water Journal February 2007  

Water Journal February 2007