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Volume 38 No 6 SEPTEMBER 2011 RRP $16.95 inc. GST

J O U R N A L O F T H E AU S T R A L I A N WAT E R A S S O C I AT I O N

PUTTING A PRICE ON WATER...

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See our report on page 50

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Journal of the Australian Water Association ISSN 0310-0367

Volume 38 No 6 September 2011

contents REGULAR FEATURES From the AWA President Global Challenges & Opportunities From the AWA Chief Executive WaterAUSTRALIA Update

Crisis? What Crisis?

Industry Capability Team Plans

Lucia Cade

4

Tom Mollenkopf

6

Les Targ

8

The Case for Change is Clear Minister Peter Walsh 10 My Point of View Water, Water Everywhere, But Ne’er A Drop to Pump John Lenders 12

An aerial view of the Woodfordia festival site. See page 32.

Crosscurrent

14

Industry News

20

AWA News

32

SPECIAL FEATURES Conference Report The Disinfection By-Products Workshop at Ozwater’11.

Steve Hrudey et al.

46

Putting a Price on Water Despite rising prices, the real cost of water services as part of an average household budget is very low. The challenge is getting this message across. Andrew Speers 50 The Carbon Pricing Scheme – Opportunity in Disguise? Carbon pricing will inevitably impact on the water industry, but at the same time it will present chances to show leadership. S Alimanovic et al. 54 AWA CONTACT DETAILS Australian Water Association ABN 78 096 035 773 Level 6, 655 Pacific Hwy, PO Box 222, St Leonards NSW 1590 Tel: +61 2 9436 0055 Fax: +61 2 9436 0155 Email: info@awa.asn.au Web: www.awa.asn.au

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

COPYRIGHT AWA Water Journal is subject to copyright and may not be reproduced in any format without written permission of the AWA. To seek permission to reproduce Water Journal materials, send your request to journal@awa.asn.au

WATER JOURNAL MISSION STATEMENT ‘To provide a journal that interests and informs on water matters, Australian and international, covering technological, environmental, economic and social aspects, and to provide a repository of useful refereed papers.’ PUBLISH DATES Water Journal is published eight times per year: March, April, May, July, August, September, November and December.

EDITORIAL BOARD Chair: Frank R Bishop; Dr Bruce Anderson, AECOM; Dr Terry Anderson, Consultant SEWL; Michael Chapman, GHD; Robert Ford, Central Highlands Water (rtd); Anthony Gibson, Ecowise; Dr Brian Labza, Vic Health; Dr Robbert van Oorschot, GHD; John Poon, CH2M Hill; David Power, BECA Consultants; Professor Felicity Roddick, RMIT University; Dr Ashok Sharma, CSIRO; and E A (Bob) Swinton, Technical Editor.

EDITORIAL SUBMISSIONS & CALL FOR PAPERS Water Journal welcomes editorial submissions for technical and topical articles, news, opinion pieces, business information and letters to the editor. Acceptance of editorial submissions is at the discretion of the Editor and Editorial Board. • Technical Papers and Technical Features Bob Swinton, Technical Editor, Water Journal – bswinton@bigpond.net.au AND journal@awa.asn.au.

Increased investment in renewable energy sources will be one impact of the carbon tax. See page 54.

Papers 3,000–4,000 words and graphics; or topical articles of up to 2,000 words relating to all areas of the water cycle and water business. Submissions are tabled at monthly editorial board meetings and where appropriate are assigned referees. Referee comments will be forwarded to the principal author for further action. Authors should be mindful that Water Journal is published in a three-column ‘magazine’ format rather than the fullpage format of Word documents. Graphics should be set up so that they will still be clearly legible when reduced to two-column size (about 12cm wide). Tables and figures should be numbered with the appropriate reference in the text (eg, see Figure 1), not just placed in the text with a position reference (eg, see below), as they may end up anywhere on the page when typeset. • General Feature Articles, Industry News, Opinion Pieces and Media Releases Anne Lawton, Managing Editor, Water Journal – journal@awa.asn.au • Water Business and Product News Lynne Bartlett, National Relationship Manager, AWA – lbartlett@awa.asn.au

UPCOMING TOPICS NOVEMBER 2011 – Energy Efficiency, GHG Emissions; Demand Management; Odour Management; IDA World Congress. DEcEMBER 2011 – Desalination – IDA Conference Report; Water Treatment; Water Reclamation. MARCh 2012 – Water in Mining; Water Recycling; Sewer Processes; Smart Water Systems/Metering; Pipelines, Controllers, Leak Detection; Rainwater Tank Technology; Environmental Impacts.

ADVERTISING Advertisements are included as an information service to readers and are reviewed before publication to ensure relevance to the water sector and the objectives of the AWA. Contact Lynne Bartlett, National Relationship Manager, AWA – lbartlett@awa.asn.au Tel: +61 2 9467 8408 or 0428 261 496.

PUBLISHED BY Australian Water Association (AWA) Publications, Level 6, 655 Pacific Hwy, PO Box 222, St Leonards NSW 1590; Tel: +61 2 9436 0055 or 1300 361 426, Fax: +61 2 9436 0155, Email: journal@awa.asn.au, Web: www.awa.asn.au

OUR COVER The cost of water services is rising in most countries around the globe, including Australia, but the message utilities want to get across is that the water in our taps is still great value for money. See our article ‘Putting a Price on Water’ on page 50 for more.

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SEPTEMBER 2011 1


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Journal of the Australian Water Association ISSN 0310-0367

contents

Residents at Buru in Queensland map their water system. See page 73.

TEChNICAL FEATURES (

Volume 38 No 6 September 2011

An aerial view of the Suncoast Sewage Treatment Plant. See page 58.

INDIcATES THE PAPER HAS BEEN REFEREED)

WASTEWATER TREATMENT Defining Treatment Plant Capacity Equivalent Population is more sensible than Average Dry Weather Flow Biogas Production Potential from Meat Processing Plant Results showed good potential for biogas production

MP Thomas

58

M Othman & S Woon

64

C Browne

67

R Grey-Gardner, R Elvin, P Taylor & M Akeroyd

73

N Dow & M Duke

78

M Wicks, N Vigar & M Hannah

83

L Ho et al.

89

AC Hambly et al.

96

Z Slavnic

102

Presented at presented

INTERNATIONAL AID PROJECTS Analysis of Breakdown of Technology Transfer in cambodia Positioning ceramic water filters as a fundamental service rather than a luxury

Presented presented at

SMALL SYSTEMS The Community Water Planner Field Guide A package to assist Indigenous communities The Potential for Membrane Distillation of Industrial Wastewaters Using waste heat to recover high-quality water from a waste stream

Presented presented at

STORMWATER TREATMENT Nutrients and Solids Removal by an Engineered Treatment Train Field evaluation of a gully pit insert and cartridge media filter water WATER TREATMENT Application of Chlorination for Cyanobacterial Toxin Control Chlorination can be an effective final treatment barrier for a range of cyanotoxins WATER RECYCLING Presented at presented

Rapid Cross-Connection Detection by Portable Fluorescence Spectroscopy Recycled water is typically able to be distinguished from potable water by a factor of 4 to 5 ASSET MANAGEMENT Water Infrastructure Benefits of asset management-centred organisations WATER BUSINESS New Products and Business Information

104

Advertisers’ Index

112

2

SEPTEMBER 2011

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from the president

Global Challenges Present Opportunities to Flourish Lucia Cade – AWA President This month in Water Journal we focus on international development, wastewater treatment and distributed systems. It is a mix of topics that reflects the current challenges in the sector on both a local and a global level. In July I was a guest at Singapore International Water Week and participated in the Leaders’ Summit, in an Australian Business Forum, and talked with water leaders from countries in South East Asia, the Middle East, southern Asia, the UK and the US. These discussions revealed to me that there is enormous commonality in the challenges we are facing in providing secure, sustainable water services for public health, high quality urban and rural environments and to support economic production, whether that be in manufacturing, agriculture or resources. We are dealing with a changing portfolio of water supplies to adapt to changed conditions – across the world established water supply options are proving insufficient because of population growth, increased variability of supply and the shift in acceptance of restrictions as a management tool. Related to this are community trust, understanding and acceptance of the different portfolio of solutions. The biggest aspect of this is how we earn the community’s trust that the solutions we propose are the best in terms of public health, safety, resource use and cost. It is often an emotional response, which we try to answer with evidence and facts.

Put simply, this means a focus of policy and investment needs to be to produce more food from the available water supply in as energy-efficient a manner as possible. This is one of the great emerging issues of the coming decades and is being discussed at policy level and think tanks everywhere – at the UN, the World Economic Forum and in the business sections of all the major world news media. Google it and you’ll find more than 14 million entries! In Australia we are seeing this most clearly in the MurrayDarling Basin debate. I like the way the World Economic Forum puts it: “Economic progress without social development is not sustainable, while social development without economic progress is not feasible”. All of the above means there is significant opportunity for Australia internationally, as the solutions we develop for our own water challenges are solutions that will work in many other parts of the world. Finally, AWA’s support of, and involvement with, waterAUSTRALIA is driven by our Board’s view that we can only achieve our vision of sustainable water management across Australia if we have a vibrant, globally competitive and innovative water sector to deliver it. The role of waterAUSTRALIA is, in part, to promote those elements of our water sector and provide further opportunities to flourish. See waterAUSTRALIA CEO Les Targ’s regular column on page 6.

Different supply options often require the coordinated approval of numerous policy, regulatory and governing authorities for different aspects of the solution. It is not just in Australia that it can be difficult to achieve efficient coordination and agreement of such entities. Then there is the water, energy, food balance – the challenge of ensuring we have enough water, energy and food to support the projected world population of nine billion people by 2050.

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from the chief executive

Crisis? What Crisis? Tom Mollenkopf, AWA Chief Executive A few weeks ago, I was a panellist in a session entitled Getting a Seat at the Policy Table. The discussion explored the approaches associations take in developing a profile for, and successfully advocating on behalf of, their industries or sectors. While preparing my comments, I reflected on how the water sector represents its interests, insights and ideas to the community and public officials. We seem not to have convinced the people of South East Queensland that corporatised regional water utilities are efficient – one need only look at the recent decision by the Gold Coast and Redlands Council to ‘secede’ from Allconnex Water. Then there is the ongoing public disquiet about increasing water charges – valuing and paying the true cost of water and sewerage services is still not accepted. There is continuing misunderstanding and resistance to desalination, even where this may be the best available option. And there remains the opposition that many in Australia (particularly politicians) have towards broader adoption of recycled water, notwithstanding the extensive science and overseas experience that support it. It occurred to me that, in speaking about effective policy engagement and advocacy, perhaps the Australian water sector was the case study of an ‘Opportunity for Improvement’. The fact that Australia underwent more than a decade of below average rainfall (a situation that persists in the west) and that we are at the ‘bleeding edge’ of dealing with climate change and the consequent warming, drying and extreme weather events that this entails, seems already to have been forgotten. The great strides that the community and the water sector have made in managing demand, introducing more efficient market mechanisms and water-saving technologies, and adding new supply sources, seems to be yesterday’s news. A series of backwards steps appears to have been taken around the nation. In Victoria several key projects such as the Sugarloaf Pipeline and the Wonthaggi Desalination Plant are now treated by the Government with disdain. In Queensland the Government’s resolve on reform of institutional structures is being tested. In Tasmania the need for investment to overcome inadequate or failing infrastructure was acknowledged, but the will to have it paid for through prices has waned. In New South Wales there is no longer even a Water Minister to champion a strategy, let alone a vision, in water management. Nationally the Murray-Darling Basin Plan is again delayed.

will. It is a reserve that is quickly drawn down when water policy becomes political cannon fodder. In this highly emotional battle, the water sector sometimes seems ill-equipped to engage and defend itself. I suspect this is for several reasons. First, in our sector many of the primary service providers are ultimately government-owned and, accordingly, may not engage in the political fray. Also, we are a fragmented sector with many different types of participants and varying interests. The sector’s ability to communicate credibly and in ways with which the community can identify will impact us all: water professionals, businesses, farmers and the general public. As a nation, poor policy means we risk not only losing the opportunity to continue to lead the world, but also the ability to ready ourselves for the next inevitable decline in rainfall. This puts us at risk of seeing our systems and capabilities fall into disrepair. Over the coming weeks we have a unique opportunity to contribute to one aspect of driving a national water agenda. The Council of Australian Governments’ (COAG) initiated review of the National Water Commission (NWC), headed by Dr David Rosalsky, was announced in late July. The Review will assess the effectiveness and relevance of the NWC in identifying and promoting water reform objectives in Australia. In a federation such as Australia, the National Water Initiative and the NWC have assumed a critical role in achieving cross-jurisdictional outcomes in an area of genuine national strategic importance. At the heart of this success are the intergovernmental agreement and the independence of the NWC. There will no doubt be areas where the role and functions of the NWC can be clarified and sharpened to deliver on emerging needs in our sector, but what is clear is that there is an ongoing need for the NWC or something very much like it. Those of us with musical tastes that acknowledge (or are stuck in) ’70s rock may remember the Supertramp album, Crisis? What Crisis?. I think we may, in fact, argue that Australia does not have a water crisis. What it does have is a need for sound water policy, ongoing maintenance of and investment in water infrastructure, a vibrant water industry, long-term commitments to research and receptiveness to innovation. It would be sad indeed if we needed a crisis to prompt the inclusion of these issues on our national agenda.

At a local level, many of our utilities have done an excellent job of communicating with and engaging their communities in specific programs and initiatives. But the hard work in building trust has apparently only delivered a fragile reserve of good

6 SEPTEMBER 2011 water

regular features


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wateraustralia update

Plans to Establish Industry Capability Teams Les Targ – CEO, waterAustralia waterAUSTRALIA has been awarded a two-year funding agreement by the Commonwealth Department of Innovation, Industry, Science and Research to establish and coordinate up to five water industry capability teams as a key initiative of the Water Supplier Advocate. The purpose of these teams is to cluster companies with complementary products and services to form strategies that will promote collective capabilities to new customer groups. The teams are industry-driven, chaired by industry members, and will pursue opportunities that member companies see value in striving for as a group. Whether domestic or international, companies can hunt in packs to access opportunities as a part of this initiative. In addition to other activities to help the development of the sector, these endeavours are delivered by waterAUSTRALIA with the support of the Water Supplier Advocate, Austrade, Enterprise Connect and Industry Capability Network.

Collaborative Opportunities Well-organised clusters with committed members work. They serve to enhance collective knowledge and capability – and all at a relatively low cost and sacrifice of time. For SMEs, in particular, they can provide a valuable network. SMEs sometimes find it difficult to verify information with trusted sources or even to access information about markets and operations of relevance to them. Larger companies too stand to benefit. The more they know and understand about the capabilities of the SMEs, the better placed they are to provide their customers with innovative and competitive solutions. Apart from any other benefits, the capability teams will provide the opportunity for peers to get to know one another and collaborate. Collaboration allows companies to access more markets and customers and to be involved in a wider range of projects, while not straying out of their core business. Collaboration depends on forming relationships with companies that have compatible ambitions, complementary capabilities and ethical business practices. They require mutual respect and trust and can be invaluable in helping companies develop. I believe there is tremendous scope for SMEs in the Australian water industry to grow through collaboration.

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Collaboration provides new opportunities for growth.

Capability Categories The categories for the capability teams will be based on interest from companies and could possibly include water recovery, reuse and treatment; irrigation; mains water; environmental services; and water-related IT. To take a possible water recovery team, just as an example, it may be that members decide to promote their capabilities to the resources sector. This is a diverse and disparate sector, more often than not remotely located. Any one company, particularly an SME, would find the business development costs quite high; the team as a whole, however, with support under this Project, develops good capability collateral and conducts an effective promotional campaign. waterAUSTRALIA would provide branding support. There will be other potential benefits of joining a team and it may be that companies may find it appropriate to join more than one. As the capability teams roll out over the next two to three months, you will be invited to participate in a national series of workshops where we will provide more information as to the likely categories for the teams, the range of activities that are envisaged, the management structure and how to join. Each team will be chaired by members to ensure that the initiatives that are adopted are industry-driven. For anyone wishing to express interest in the meantime, please drop me a line at: ceo@wateraustralia.org

regular features


my point of view As with other eastern Australian states, recent decades have seen Victoria face extreme climatic conditions that have posed significant challenges for the water sector. For this issue’s ‘My Point Of View’ we asked Peter Walsh, Victorian Minister for Water, and John Lenders, Leader of the Labor Party in Legislative Council and Labor Spokesman for Water, for their views on how the state’s urban water system can best be managed to ensure future water security.

The Case for Change is Clear Peter Walsh, Minister for Water and Minister for Agriculture and Food Security, Victorian Government. The Victorian Coalition Government has embarked on a major reform of urban water policy in Victoria. As the state emerges from more than a decade of drought, water customers have found themselves lumbered with expensive, large-scale infrastructure projects – the legacy of the previous Government, which failed to plan for the state’s long-term water needs.

of stormwater was reused, while just 21GL of the 297GL of sewage was recycled for use on parks and gardens. Better integration of the city’s water supplies also has the benefit of healthier urban waterways, more green space and a reduced heat island effect, all at a lower overall cost than offered by purely traditional water supply and demand solutions.

Instead of augmenting the state’s water supplies in a sensible and considered way, the former Labor Government panicked and signed Melbourne households up to the excessive 150-gigalitre Wonthaggi desalination plant. For the consortium building the plant, the contract is rolled gold. It will see customers paying $654 million net present value for the next 27.75 years – irrespective of whether water is delivered or not.

The council’s roadmap outlined a vision to: manage our water requirements using all of the water that comes into the system; make the system more open and transparent; support a more contestable water sector while retaining government ownership of water authorities; better integrate urban development planning processes and water planning processes; acknowledge the full costs and benefits of water services; embed water efficiency within the community; and deliver a more resilient and adaptable water system for Melbourne.

The $750 million North-South pipeline, which was built from the Goulburn River in the state’s north to Sugarloaf Reservoir, has also proven to be a white elephant. In an average year, when Sugarloaf is operated in a way to maximise flows within its own catchment, the reservoir does not even have the capacity to store water from the North-South pipeline. With the city’s population expected to increase from 4.1 million to 6.4 million by 2056 and the demand for potable water forecast to increase from 356 GL to more than 534 GL, the case for change is clear. Melbourne needs a more resilient and adaptable water system that is better equipped to live within its existing water supply resources.

In order to deliver this plan, the council mapped out a series of reform priorities, including: 1.

Agree to a vision for the contribution of water to urban liveability, around which communities can agree how water resources are managed and used to create a more liveable and productive city;

2.

Facilitate greater customer choice and innovation in the water services customers receive and charges they pay;

3.

Improve the integration of urban and water planning to address water, energy and sustainability issues that are more difficult to address at smaller scales (eg, single buildings);

4.

Optimise the use of all available water sources by taking a ‘whole of system’ view that considers all options;

5.

Establish clear environmental and health outcomes for all aspects of water supply, use and treatment;

6.

Establish a common approach to economic evaluation that accounts for the full costs and benefits of different options;

7.

Review approaches to the pricing and valuing of all water resources so that we value the water resource itself and reward customers for conserving water; and

8.

Strengthen the current institutional and governance arrangements so that information about service opportunities is open to all, and each element of the water system can play its part in delivering the best outcomes for the community.

A Roadmap for the Future In January this year I appointed the Living Victoria Ministerial Advisory Council to provide strategic advice on the changes required to deliver the Coalition Government’s policy. The council includes Mike Waller, immediate past chair of Sustainability Victoria, former Melbourne Water managing director, Rob Skinner, Melbourne City Council’s director of city design, Rob Adams, and Strategies for Change managing director, Sue Holliday. The council delivered its initial report – The Roadmap for Living Melbourne, Living Victoria – in March. The roadmap identified priority areas of urban water reform for Melbourne and highlighted the higher level changes to the management of Victoria’s urban water systems that the council believes are required to support more liveable communities. The analysis suggests a paradigm shift in the way we use water would significantly delay the need to undertake another large-scale augmentation of Melbourne’s water supply system. For example, in 2009–10 only 10GL out of an available 463GL

10 SEPTEMBER 2011 water

It is a thorough process and one which I believe will lead to a transformation of Victoria’s urban water system.

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my point of view

Water, Water Everywhere, But Ne’er a Drop to Pump John Lenders, Leader of the Labor Party in the Legislative Council, and Labor Spokesman for Water, Agriculture, Resources and Commonwealth State Relations. In Victoria we are awash with water. Aside from devastating floods in September last year and January this year, the increased flows have been a blessing for most Victorians and, especially, Victorian farmers. After years of drought, there is finally some relief and some water security for Victorians. Melbourne’s catchments have now exceeded 60 per cent for the first time in 10 years – and they were just 25 per cent two years ago – while across Victoria our catchments are at 79 per cent and rising. This is great news for Victorians. Amid this period of heavy rain and good inflow into our major catchments, there could be no better moment than now to secure the long-term water security of all Victorians. The best way to do this is to build up Melbourne’s water storages, while at the same time avoiding putting into jeopardy the water entitlements of farmers in northern Victoria. This is an important balance. To achieve it requires the Victorian Government to start pumping water from Lake Eildon, Victoria’s second largest water storage, into Melbourne’s catchments via the NorthSouth Pipeline. Sadly, the Victorian Coalition Government is implacably opposed to opening up the North-South pipeline. It has been plugged. The first reason provided by the Minister for Water, Peter Walsh, as to why this could not be possible was that the water from Lake Eildon would need to be pumped directly into the Sugarloaf Reservoir, a catchment in Melbourne’s outer north, and that Sugarloaf is currently full. That is a sensible explanation if it were entirely true. However, when it was put to the Minister at a Public Accounts and Estimates hearing in May that Melbourne Water, the respective governing body, could easily move water around Melbourne’s catchments and distribution network to make room for water to be pumped into Sugarloaf, which it has the capacity to do, the Minister’s response was considerably less rational: “We have been very clear all the way through about our opposition to that project [the North-South pipeline] … We have set out very clearly what we think about the North–South pipeline.” The reality is, because Mr Walsh has plugged the NorthSouth pipeline, Melbourne families will not get the $300 million worth of water they have paid for; this will consequently put up the price of water – above what is needed to finalise the desalination plant.

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Cost-of-living Pressures I visited Lake Eildon recently. It is almost full, and as a result more than one week’s worth of Melbourne’s water supply was being released out of Lake Eildon every single day and down into the Murray River and along to South Australia. Why? Because the Baillieu Coalition Government refuses to open the North-South pipe and pump the water south to Melbourne to fill Melbourne’s catchments. As a result, Melburnians are worse off. They are paying more for their water, which is putting increasing pressure on the cost of living. For a Government that has committed itself to easing cost-of-living pressures on Victorian families, it is in fact doing the opposite, because of its ideologically blinkered approach to water. So when dam levels do drop north of the divide in the future, there will be another divisive argument that could have been avoided if the Minister was willing to store some of today’s water glut in the 40% of Melbourne’s dams that is currently airspace. Not only does the Minister attack the North-South pipeline, but also the Goldfields Superpipe and the Melbourne-Geelong pipe. A water grid is incredibly important, particularly when it comes to providing water to a Melbourne population of four million, and a Victorian population of more than five million. But, for purely ideological reasons, it is being attacked. Instead, we are seeing more money being spent on further expensive augmentations. It’s high time that we got rationality back to the debate about how best to provide water to an increasingly growing Victorian population. In a time of intense drought, the previous Labor Government commissioned the construction of a desalination plant near Wonthaggi in South Gippsland. This was a decision made in the interests of securing Victoria’s long-term water security and, in particular, Melbourne’s water security. The desalination plant was commissioned with that sentiment in mind, and was a vision for the long term. Water is a valuable commodity, and while Victoria may be awash with water at the moment, this will not always be the case. The time is now for enforcing water policies in the interests of all Victorians.

regular features


my point of view

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SEPTEMBER 2011 13


crosscurrent

National Water Minister Tony Burke has announced delivery partners for the second round of grants under the Government’s successful On-Farm Irrigation Efficiency Program, which is helping irrigation communities boost efficiency in on-farm water use and returning more water to the environment. More than 600 irrigators in the Murray-Darling Basin will be backed by the Gillard Government to undertake projects to improve irrigation efficiency, with water saved to be returned to the environment. Nine regional organisations and irrigation businesses will share in $150 million in in-principle funding for projects to upgrade on-farm infrastructure in the southern-connected Murray-Darling Basin and the Lachlan River catchments.

The ACCC has issued pricing principles for price approvals and determinations made under the Water Charge (Infrastructure) Rules (WCIR). The WCIR provide for price approvals and determinations of certain rural water infrastructure operators in the Murray-Darling Basin by either the ACCC, or a state agency accredited by the ACCC.

The National Water Commission (NWC) has issued a report titled, A framework for managing and developing groundwater trading. The report sets out a management framework that provides a structure to establish or develop groundwater markets in a range of situations. It builds on economic theory, existing groundwater management arrangements, the National Water Initiative (NWI) agreement and related developments in national water management. The report found that trade in groundwater entitlement represents about five per cent of all water entitlement traded in Australia, and groundwater allocation trades account for approximately 10 per cent of all allocation traded.

Irrigators will judge Murray-Darling Basin reform on environmental outcomes and balance with social and economic impacts, not a simplistic focus on numbers and volume that ignore the complexity of river management, according to a position paper released last month by the National Irrigators’ Council (NIC) titled, A Balanced Plan for the Murray-Darling Basin. The NIC says reform will require trade-offs to balance competing environmental, economic and social objectives, that river health requires more than just additional volumes of water and that investment in irrigation and environmental infrastructure provides a win-win outcome.

The report Community Impacts of the Guide to the Proposed Murray-Darling Basin Plan is now available. This report is an in-depth retrospective about how the proposals in last year’s Guide would have affected communities in the Basin. It analyses the socio-economic vulnerability of communities based on the Guide’s proposals. It also identifies a set of policy options that can be developed and implemented so that environmental results can be gained at a lower socio-economic cost to Basin communities. The National Irrigators’ Council said the report

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clearly indicated that a Plan that favours the environment without regard for social and economic impacts will cost jobs and threaten family farms and communities in regional Australia.

Australia is leading a $16 million international research project into why and when buried water pipes burst. This is the largest international research collaboration led by Australia on water pipes, and has worldwide significance as buried pipes provide around 70 per cent of the world’s urban water supply. The five-year project, funded by seven Australian water authorities, the US Water Research Foundation, and UK Water Industry Research Ltd (UKWIR), will produce advanced techniques and technologies to accurately predict the remaining life of buried pipes and protect against pipe bursts. Sydney Water, the largest urban water utility in Australia, will contribute $5.5 million to the project.

DSEWPC reports that three companies have agreed to improve their business practices and staff training after failing to comply with national water efficiency labelling and standards legislation. Three companies from the Australian Capital Territory, Queensland and Victoria respectively have agreed to improve their business practices and provide awareness training to staff after failing to comply with national water efficiency labelling and standards legislation at their business premises. Go to www.environment.gov.au/about/media/dept-mr/deptmr20110808.html for more information.

New South Wales Irrigation efficiency in the Murrumbidgee will be boosted by a Gillard Government project to upgrade water delivery systems and return water to the environment. Water Minister Tony Burke has said work would get underway on a $50 million project, to be delivered in partnership with Murrumbidgee Irrigation, to upgrade the region’s irrigation systems and return six billion litres of water back to the Murray-Darling.

The NSW Government has axed nine water programs in a bid to increase the value of Sydney’s desalination plant before privatisation, the Greens claim. According to a recent media report, the schemes achieved water savings of 8.1 billion litres in 2009–10 and were forecast to save a further 8.8 billion litres in 2010–11. As part of its promise before the March State Election, the Government is planning to privatise the $1.89 billion plant, which produces water at a cost of 62 cents per 1000 litres.

The Deputy Director of the NSW Liberals, Richard Shields, is taking up the position of Manager – External Relations with mining company Metgasco, which is developing large natural gas reserves in the Clarence-Moreton Basin in northern NSW. The company also has plans to construct a 145-kilometre gas pipeline from Casino to Ipswich in Queensland. However, the plans have met with opposition from community groups concerned about the potential impact of coal seam gas mining on the state’s aquifers.

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crosscurrent Apartment dwellers may face increases in their water bills as a result of a review being conducted by the Independent Pricing and Regulatory Tribunal (IPART). Because apartments generally don’t have individual water meters, their water bills are lower than those of stand-alone houses. IPART says that at present multi-premise dwellings pay only about 40 per cent of the residential water service charge paid by freestanding houses in Sydney Water’s area.

Queensland Industry and science have come together with the launch of a new research alliance to support the sustainable development of the coal seam gas (CSG) industry. The alliance was officially launched by CSIRO Chief Executive Dr Megan Clark and Page Maxson, Project Director, Australia Pacific LNG. Dr Clark said the Gas Industry Social and Environmental Research Alliance (GISERA) has been founded by CSIRO and Australia Pacific LNG (a CSG to LNG joint venture between Origin and ConocoPhillips) to undertake research in five key social and environmental areas: groundwater and surface water, biodiversity, land management, the marine environment and socio-economic impacts.

Northern Territory Alice Springs will save up to 1.6 billion litres of drinking water a year as part of a two-year initiative to reduce the pressure on groundwater resources in the local aquifer. Launching the Alice Water Smart project last month, Senator Don Farrell, Parliamentary Secretary for Sustainability and Urban Water, said the Australian Government is providing funding of $7.49 million to the project to assist with measures including recycling and reuse of wastewater, leak reduction, efficient town irrigation, and smart metering.

South Australia South Australia’s Labor government has supported the rights of coal-seam gas miners to access private land to explore and extract gas deposits, stating coal seam gas has an increasingly important role in the state’s energy security. South Australian Mining Minister Tom Koutsantonis admitted that South Australia did not face the same political pressures as Queensland and NSW, where most of Australia’s coal seam gas is deposited, as it had adopted a co-operative approach to potential disputes between miners and landholders.

Victoria The United Nations Association of Australia (Victorian Division) has held a panel discussion entitled Natural Capital in Victoria: Towards a Sustainable Economy? as part of the lead-up to the next United Nations Conference on Sustainable Development

16 SEPTEMBER 2011 water

(Earth Summit) to be held in Rio de Janeiro in June 2012. Guest speakers included: Phillip Glyde, Executive Director, ABARES, and Rob Skinner, Living Victoria Ministerial Council and former CEO of Melbourne Water.

Victorian Minister for Water Peter Walsh recently opened two significant water storage projects benefiting the remote East Gippsland communities of Mallacoota and Omeo. Mallacoota’s second town drinking water storage is now protected by shade cloth to improve water quality in the 41 million-litre storage, while at Omeo the construction of an additional 10 million-litre storage will increase the town’s drinking water storage capacity from 5 million to 15 million litres.

Use of Victoria’s environmental water entitlements will become more efficient, transparent and accountable thanks to the creation of the Victorian Environmental Water Holder (VEWH). The Water Holder, which met for the first time last month, is Victoria’s new independent body for holding and managing the state’s environmental water entitlements.

Minister for Water Peter Walsh has slammed the MurrayDarling Basin Authority (MDBA) for refusing to hold open community meetings across Victoria’s basin communities. “The Murray-Darling Basin Authority is not showing us they are prepared to engage with communities in an open and transparent way,” Mr Walsh said. “Craig Knowles’ refusal to front up to open community meetings is clearly aimed at controlling any adverse community reaction following the release of the plan. Basin communities need to be involved in the development of the plan, not just its implementation, because it will affect people’s lives, businesses and futures.”

The final section of pipe has been laid in a $60 million main replacement project to save water and strengthen security of supply in Melbourne’s northern and western suburbs. The replacement of the 10.5-kilometre water main between Preston and North Essendon started in February 2009 and was completed over eight stages. Water Minister Peter Walsh said the replaced main was more than 100 years old and had reached the end of its service life. The main replacement is one of several large-scale water and sewerage projects underway across Melbourne to ensure essential infrastructure continues to meet the demands of the city’s population growth.

Tasmania The $54 million rollout of water meters in Tasmania has been criticised for being behind schedule, riddled with problems and facing a cost blowout. By mid-August it was claimed only 9000 of a scheduled 24,000 meters had been installed on Hobart’s Eastern Shore and homeowners were complaining of shoddy workmanship, faulty meters, trampled gardens and poor communication from the state’s water corporation.

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Developing properties in built up areas near water and sewer pipes What do you need What is best practice? to do? Before you disturb an asset belonging to a water utility you need to get their permission. Remember that the asset you may be thinking of disturbing is most likely serving a number of customers in the area and that any interference with the asset could affect their service. In regard to sewerage assets there are health and environmental implications for those working on the job as well. Water utilities, such as City West Water, South East Water and Yarra Valley Water are only too ready to help you with your development. A simple telephone call can get the ball rolling.

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Before you start a development talk to you local water utility to see how the development might affect the local water supply and sewerage systems, and find out what needs to done so that your development will proceed smoothly. Melbourne’s water utilities are standing by to help you with your development. No one likes to hold up work and an early approach will avoid any future problems.

Who does this apply to? Developers use contractors for their building works, and these in turn often use subcontractors. Everyone involved in

a development needs to make sure that before they work on an existing water supply or sewerage pipe they have the right approvals from the pipe’s owner.

What does the law say? Section 63 of Water Industry Act 1994 says that you must not connect to or remove any works from water utility assets without first obtaining a permit. Section 66 goes on to say that you must not place filling or build a structure on, over, or within one meter of a water utility asset. Did you know that this is legislation and that by not complying you are breaking the law? You can be fined or even go to prison as a result. Why take the risk? Contact your water utility before you begin works.

Who to call? City West Water on 13 1691

South East Water on 13 92837

Yarra Valley Water on 13 2762

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Member News Roch Cheroux has been appointed CEO of water services company Degrémont, Australia New Zealand. Mr Cheroux has 20 years’ experience in the water industry in design, construction, financing and operating activities, including being CEO of a listed water company in Europe and, more recently, managing director of United Utilities Australia until it had a change of ownership in November last year.

Dr Therese Flapper has joined GHD’s Canberra office as Service Group Manager – Water and Environment.

Parsons Brinckerhoff Australia-Pacific has appointed Brian Ashcroft as the Section Executive for Environmental Assessment, Planning and Stakeholder Engagement.

The University of Wisconsin-Milwaukee has appointed David Garman as the first dean of the School of Freshwater Sciences. Garman currently works at the Environmental Biotechnology Cooperative Research Center and is the immediate past president of the International Water Association.

2ND ANNUAL NATIONAL WATER LEADERSHIP SUMMIT HYATT CANBERRA 2 - 3 NOVEMBER 2011 Themes include: • Structural and Governance Reform in the Urban and Rural Water Sector; • Opportunities and Barriers to Private Sector investment in Water; • Management of Assets in a Carbon Constrained Future. Who Should Attend? Chief Executives, heads of department, decision-makers and industry leaders, senior managers, regulators, policy makers, thought leaders and those interested in the leading edge of water sector management in both urban and rural areas.

Earlybird registration closes 30 September 2011 For full program and registration details:

awa.asn.au/events/NWLS11 DINNER SPONSOR

18 SEPTEMBER 2011 water

Joe Flynn is leaving the role of CEO of the South Australian-based Water Industry Alliance. Andy Roberts will be taking over as CEO from mid-August. Andy is currently the Alliance’s Industry Development Manager.

Ian Slape has returned to the Queensland Branch of KSB Australia. Ian’s new role is Sales Engineer – Water and Waste Water.

John Cowan has been appointed CEO of Optimatics. John will be supported in his role by a new Board of Directors comprising Ivan Gustavino as the Chairman, company founder Dr Graeme Dandy and Paul Moroney.

The Australian Water Recycling Centre of Excellence Research Advisory Committee has appointed a new Chairperson. Dr John Radcliffe currently chairs the Australian Academy of Technological Sciences and Engineering (ATSE) Water Forum, is a Council Member of the University of Adelaide and Chairman of the Commonwealth Department of Agriculture, Fisheries and Forestry Eminent Scientists Group. He began his new role with the Research Advisory Committee in July.

AquApheMerA The Queensland Floods Commission of Inquiry interim report released on 1 August 2011 (www.floodcommission.qld.gov. au/publications/interim-report) in itself appears reasonable. However, as expected, the media – with the classic wisdom of hindsight and needing to find someone to blame rather than Mother Nature – has unreasonably laid open the SEQW flood managers to litigation. The real issue appears to be: should the engineers have accepted the Bureau of Meteorology’s predictions and dropped the level of Wivenhoe reservoir and risked ongoing severe water restrictions for the people of South-East Queensland, or, acted as they did and risked possible floods? After just going through the worst drought on record and the worst water shortages and restrictions ever experienced, what technically experienced flood operations personnel, in the real time of flood operations, would have ignored the operations manual and made a decision to send 25% of the most critical water supply for South-East Queensland down the river on the chance a significant flood may actually eventuate? As a former flood forecaster, I certainly wouldn’t! The Bureau’s forecasts are of great benefit, but unfortunately they aren’t always right. Interesting recommendations in the interim report endeavour to ensure the Minister is held responsible for these decisions in future. How ridiculous! To expect someone without the experience or technical knowledge to assimilate all the information, the conflicting requirements and threats, in a pressure cooker real-time situation and expect them to make the best decision is a cop-out. The best outcomes will be achieved by all the organisations listed in the report being involved in developing the manual, utilising the best knowledge, experience and technology available to arrive at the operating procedures. If a situation arises where it is outside the manual instructions and a value judgement is required, then call in the Minister. – Ross Knee

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SEPTEMBER 2011 19


industry news WSAA’s 2011 Report Card The WSAA 2011 Report Card was launched last month by Adam Lovell, Executive Director of Water Services Association of Australia (WSAA). The report outlines a series of recommendations to help the industry identify opportunities and challenges in the future. WSAA highlights responsiveness to customers, value for money, planning for sustainable urban communities, and minimising the impact of the industry on the environment as areas of future focus. The report makes recommendations in planning, building capability, cost effective services, industry reform and implications on the industry of the proposed carbon tax. Mr Lovell praised the urban water industry for its response to the extreme weather events that Australia has endured over the past 12 months. “I am pleased to say that despite the challenging conditions, the quality and supply of water and sewage services was maintained, including the use of desalinated water in Brisbane during the floods. The delivery of safe drinking water always remains a top priority for urban water,” he said. The report makes recommendations on ‘Providing value for money for water services’ and notes a move to water efficiency away from water restrictions. “A typical resident in an Australian capital city spends around 2% of average earnings on their water and sewage bill. WSAA believes that for around $2 per tonne, the delivery of clean, healthy water to your home 24/7, this represents exceptional value for money.” The report makes 20 recommendations in the five key areas, and is available from the WSAA website: www.wsaa.asn.au

SKM Announces Chilean Merger Leading Chilean water engineering consultancy IRH has merged with global projects firm Sinclair Knight Merz (SKM) to offer new water and environmental services to organisations across South America. IRH specialises in the implementation and management of projects related to water supply, water networks, urbanisation, stormwater systems, water and sewage treatment, environmental management and hydraulics. SKM Chief Executive Paul Dougas said the acquisition of IRH is a direct response to the needs of clients in South America, especially in the mining sector. IRH has a diverse client base across both the private and public sectors in Chile, including CODELCO, Aguas Andinas, Essan, the Government of Chile Public Works Department, a range of large commercial and retail clients, and Chile’s largest petrol retailer, Copec.

National Water Commission Review The National Water Commission will be reviewed to assess the effectiveness and continuing appropriateness of its roles in promoting water reform objectives and outcomes. The external review, which is required by the National Water Commission Act 2004, will also provide advice on appropriate options and institutional arrangements for implementing functions which the review considers should continue or commence. Parliamentary Secretary for Sustainability and Urban Water, Senator Don Farrell, has appointed Dr David Rosalky to conduct the review.

20 SEPTEMBER 2011 water

“Dr Rosalky brings a wealth of expertise to the job, including more than 30 years’ experience in senior government positions in Australia and Canada,” Senator Farrell said. “He has conducted reviews of public policy and expenditure programs and is a visiting fellow in policy and governance at the Crawford School of Economics and Government at the ANU.” Dr Rosalky will conduct the review on behalf of the Council of Australian Governments (COAG). He will be supported by a secretariat from the Department of Sustainability, Environment, Water, Population and Communities (DSEWPC), accountable to the reviewer. “Given the national significance of managing Australia’s water resources wisely, this review is a very timely opportunity to consider what roles and functions will assist the ongoing process of water reform,” Senator Farrell said. The review will be provided to COAG by the end of the year. Further information on the review can be found at: www.coag.gov.au

Nubian Names New General Manager Nubian is pleased to announce Arna Holden as General Manager of Customer Experience. Arna comes to Nubian with extensive experience in improving customer service, client retention and efficient logistics production. Arna’s core responsibility is to develop and implement strong operational systems, strategic processes and growth components to lead excellence within the business and for all stakeholders.

Arna Holden

CEO of Nubian, Barry Porter, comments, “We are delighted to have Arna on board. Her expertise with managing customer service and initiatives in driving growth and excellent operational process makes her a welcome addition to the Nubian team. Arna’s appointment cements our ongoing commitment to strengthen the Nubian brand and enhance customer experience at every touch point.” Arna was previously National Customer Service Manager and Operations Manager at Rentokil Initial, and was Learning and Knowledge Manager of leading multinational dairy company Fonterra in New Zealand.

Dr James Barnard Wins Water Prize Dr James Barnard has won the Lee Kuan Yew Water Prize 2011. He received the award at Singapore International Water Week (SIWW), where he also delivered the Singapore Water Lecture. Dr Barnard, a Global Practice and Technology Leader for Advanced Biological Treatment at Black & Veatch, began his professional journey in his native South Africa and arid Namibia in the 1970s, where challenges such as eutrophication were having severe impacts on the countries’ river systems and waterways. Inspired to find a more cost-effective and environmentally sustainable solution, he explored the possibility of removing phosphorus and nitrogen from used water through biological means only. The result was the invention of the

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Dr James Barnard at Singapore International Water Week. Biological Nutrient Removal (BNR) process. Today, variations of the BNR process have been implemented in hundreds of facilities across North America, Europe and Africa. “What’s often misunderstood is that nature is, in fact, very reliable as long as you can recreate and manage the optimal conditions,” Dr Barnard said. “The simplest analogy of how the BNR process works that most people intuitively grasp is how for centuries we have understood and harnessed micro-organisms to brew beer or make cheese.” The development and implementation of the BNR process has transformed wastewater treatment around the world by substantially reducing the reliance on chemicals for removing phosphorus and nitrogen. Today, research continues to focus on improving the efficiencies of the process but also explores ways to recover these life-giving and dwindling natural resources, critical ingredients in fertilisers.

Stormwater Solutions Blueprint Researchers from Monash, Melbourne and Queensland Universities have collaborated for the past 12 months with over 49 industry and government partners around Australia on an innovative, multi-disciplinary, five-year research program to assist Australia’s transition to designing more water-sensitive and liveable cities. Establishing water-sensitive cities will involve significant departures from the conventional urban water management approach; Water Sensitive Urban Design is the process of enabling us to adapt our cities to a wide range of possible seasonal rainfall and water demands that science confirms will result from climate change. Since its inception in 2010, the Cities as Water Supply Catchments research program has focussed on providing practical, tangible solutions to harvesting stormwater by improving existing infrastructure, implementing new environment-friendly systems, and progressing policies to support how to build, operate and maintain more liveable Australian cities. The blueprint2011 – Stormwater Management in a Water Sensitive City articulates how, through a holistic approach to the management of urban stormwater, Australia can transition to a more water-sensitive approach. At the NSW launch Professor John Thwaites, Chairperson of the Management Committee of the research program commented, “The research program to date has provided important insights on the vast potential in managing stormwater beyond its immediate benefits as a viable alternative water resource. We are beginning to connect and quantify the benefits associated with improving urban liveability through supporting

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SEPTEMBER 2011 21


industry news

Better management of urban stormwater will produce more livable, water sensitive cities. extensive greening of cities to mitigate urban heat and to improve the ecological value of the green and blue corridors in cities”. For more information about the Cities as Water Supply Catchments Research Program and associated outputs, please contact Professor Tony Wong, Director and Chief Executive, Centre for Water Sensitive Cities, Monash University, email: tony.wong@monash.edu.au

IDA Raises $120,000 for Water-Poor The International Desalination Association’s (IDA) landmark ‘Desalination Industry Action for Good’ conference has raised $120,000 to help alleviate water shortages for residents of Ankililoaka, Madagascar. IDA’s contribution of $60,000 to this humanitarian project was matched by Rotary International, which supported the conference. Held recently in Portofino, Italy, this event was the first dedicated solely to the topic of desalination and social responsibility. Ankililoaka is home to 100,000 people, approximately half of whom are children. Currently, these people have access to only

one well for every 1,800 inhabitants. Many of them are dug by hand. With the funds donated by IDA and Rotary, at least 20 new wells will be dug over the next two years. In addition, the project will reactivate existing wells that are no longer operational. This will significantly improve residents’ access to drinking water by providing one well for every 500 inhabitants.

New CEO for Queensland Urban Utilities Queensland Urban Utilities has appointed Ian Maynard as the company’s new chief executive. The state’s largest water utility and the fourth largest in the country, Queensland Urban Utilities delivers water and wastewater services to 1.3 million residents in South-East Queensland. “For all water companies, a key challenge is improving customer understanding of the inherent value in the products and services that water utilities provide,’’ Mr Maynard said. “For a long time in Australia we have taken for granted that we have access to clean, fresh drinking water simply by turning on the tap. We want our customers to fully understand what it takes to deliver high quality drinking water to their taps and what’s involved in taking away wastewater through the simple push of a button.’’

Suppliers and subcontractors – expressions of interest Murrumbidgee Irrigation Ltd has established the MIA Renewal Alliance to carry out modernisation infrastructure works that will improve productivity and create water savings for the future. The Alliance is made up of Murrumbidgee Irrigation, GHD, John Holland Group and UGL Infrastructure. Infrastructure works are expected to commence from early 2012, subject to project planning and funding approvals. The MIA Renewal Alliance is therefore calling for expressions of interest from suppliers and subcontractors who may wish to provide their services to the Alliance in the future. This will provide the Alliance with the opportunity to assess the capability of interested organisations and further develop supplier and subcontractor capability to ensure compliance with the relevant requirements. Those organisations and individuals who respond will be asked to complete a confidential questionnaire relating to their current capacity, experience and capabilities.

Expressions of interest should be forwarded by 30 September 2011 to: Mr Ian Butler Delivery Manager Murrumbidgee Irrigation Area Renewal Alliance PO BOX 716 Griffith NSW 2680

The National Code of Practice for the Construction Industry (the Code) and the Australian Government Implementation Guidelines for the National Code of Practice for the Construction Industry, reissued August 2009 (the Guidelines), apply to this project. By agreeing to undertake the works, you will be taken to have read and to agree to comply with the Code and Guidelines.

To know more please email miainfo@miarenewal.com.au

22 SEPTEMBER 2011 water

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THINK PIPES. THINK PVC.

Photo by The Wimmera Mail-Times

Versatility, cost effectiveness and an excellent track record makes PVC the most important polymer in plastic piping and its quality and safety helps to contribute to the environmental sustainability of completed construction projects. PVC PERFORMANCE

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PVC SUSTAINABILITY PVC is one of the most well researched and tested materials in terms of environmental credentials. At least 60 reputable life cycle assessments have

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sound when compared to alternative materials.

CASE STUDY / WIMMERA MALLEE PIPELINE PROJECT The Wimmera Mallee Pipeline represents one of Australia’s most significant water-saving projects. Officially opened in April 2010, the project was completed in just under four years, well ahead of the ten year timeframe originally proposed and under the original $688 million budget. The project involved building almost 8,800

project, accounting for over 80% of the total

pipes are available with deep insertion, push-

kilometres of reticulated pipeline to replace

length of the project.

together gasketed or solvent cement joints.

17,000 kilometres of inefficient open channels, saving around 103 billion litres of water a year.

PVC pipe’s non-corrosive nature and resistance to chemical attack renders it nonreactive with drinking water. PVC pressure

Gasketed PVC pipe joints have consistently outperformed those of traditional pipe products in actual service.

The system will supply the region with a

pipes do not adversely alter water quality

PVC pipes are simple and easy to assemble

sustainable water supply for over 100 years,

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and gasketed joints can be filled, tested and

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water pipes have been tested extensively

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economic expansion within the region and

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return some water for environmental flows to

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rivers, lakes and wet lands. PVC pipes have played a major role in this

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techniques and contributed to the economic

piping applications is joint tightness. PVC

viability of the project.

For more information visit www.thinkpipesthinkpvc.com.au 1300 844 657 water SEPTEMBER 2011 23


industry news Mr Maynard cites a simple comparison that puts his value messages into perspective. “For the same price you spend on a one-litre bottle of water at the shop, you get 600 litres of drinking water through the tap,’’ he said. “The point is that if we make it easier for our customers to understand how the water purification and sewerage treatment processes work, they will better appreciate the value of the services provided by water utilities. This in turn will make it easier for customers to understand the drivers behind the prices, the access charges and the volumetric charges that are listed on their quarterly water bills.’’

Protecting Our Global Waterways Governments must ratify a global watercourse convention that can help address the world’s water crisis, avert future catastrophes, such as the ongoing Horn of Africa drought, and ensure all people have sufficient and sustained access to water, according to Green Cross International (GCI), an independent non-profit organisation founded by Mikhail Gorbachev.

These rivers and the groundwater linked to them are shared by 145 countries and their basins are home to 40 per cent of the world’s population. Thirty-five countries must ratify the UN Watercourses Convention for it to come into force. So far, 24 countries have done so, including Morocco and France. Green Cross International’s Water Programme director, MarieLaure Vercambre, says 900 million people live without secured access to clean water and one-third of the world’s population live in countries that are water-stressed, or receive inadequate amounts of annual rainfall. “Extreme weather events, such as the drought affecting East Africa, remind us the stakes are global. Greater cooperation and more rules on managing shared watersheds are needed as each country will be impacted, directly or indirectly, by how well other countries manage their water resources.”

“The acute crisis currently hitting the Horn of Africa highlights human vulnerability to severe droughts and illustrates that threats to global security and social justice of the global water crisis are upon us,” says GCI President Alexander Likhotal. Green Cross International marked the closing of the annual World Water Week forum in Stockholm, Sweden, by urging all countries to ratify the UN Watercourses Convention, the only global legal instrument governing the use, management and protection of the world’s 276 trans-boundary watercourses.

Merck Millipore are specialists in water analysis systems and laboratory reagents. What else can Merck Millipore do to assist you? Merck Millipore ... PLUS Merck Millipore can provide you with a complementary range of laboratory consumables. • BRAND Liquid Handling and volumetric glassware • Kartell re-usable plasticware - when glass cannot be used • Mediflex personal protection products - disposable gloves • SCHOTT DURAN glassware Contact Merck Millipore on 1800 335 571 www.merck-millipore.com

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SEPTEMBER 2011 25


industry news Scholarships Fund Desal Research Twenty scholarships for new desalination research worth $580,000 have been offered to university graduates by the National Centre of Excellence in Desalination Australia (NCEDA). NCEDA announced the funding for six national PhD supplementary scholarships over three years and five one-year Honours scholarships to investigate improvements in desalination technologies. In addition, four Western Australian state government-funded PhD supplementary scholarships for research into innovative desalination have been awarded to graduates from WA’s four leading universities, worth $50,000 over three years. NCEDA CEO Neil Palmer says the scholarships represent sound investment in Australia’s scientific and economic future and will build the country’s desalination industry capacity. Projects funded by the new Centre scholarships include investigation of inland desalination systems, novel low-grade heat-driven desalination, brackish water desal systems which capture water vapour, and hybrid bioreactor systems.

New SMF Board Members Victoria’s Building and Plumbing Industry Commissioner Tony Arnel and PricewaterhouseCoopers Australia (PwC) Partner Liza Maimone have been appointed to Sustainable Melbourne Fund’s independent Board of Trustees. Sustainable Melbourne Fund (SMF) Chairman Robert Jamieson said the appointments brought a wealth of expertise that would build upon SMF’s position as a Adleader Aeration176x125 rz01 20.07.2011 Seite 1benefits in assisting w21 businesses to capture9:00 the Uhr economic of sustainability in the built environment.

“Tony Arnel brings significant experience in senior leadership positions with a focus on the building sector, as well as complementary board experience, including his current roles as Chair of both the Green Building Council of Australia and the World Green Building Council,” Mr Jamieson said. “Liza Maimone leads PwC’s Sustainability and Climate Change practice in Australia and has over 16 years’ experience in sustainability management.” Mr Jamieson said the appointments came at a key time for SMF as it supported the delivery of a world-first environmental upgrade finance mechanism as part of the City of Melbourne’s 1200 Buildings program. Mr Arnel and Ms Maimone join existing Sustainable Melbourne Fund Board members, National Practice Head of Blake Dawson’s Environmental Team, Robert Jamieson, Independent Director and Chairman of Investment Committee at Combined Fund, Brett Lazarides, CEO of Tricia Caswell + Associates, Tricia Caswell and Executive Director of ClimateWorks Australia, Anna Skarbek.

$126 Million for Emerging Renewables Australia’s transition to a clean economy has received a boost with the opening of the Federal Government’s $126 million Emerging Renewables program. The program was launched by the Minister for Resources and Energy, Martin Ferguson, at the C M Y CM MY CY CMY K Australian Solar Institute.

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SEPTEMBER 2011 27


industry news “I would like to congratulate Mr Ferguson and the Gillard Government for choosing to invest today in Australia’s clean energy future,” Clean Energy Council CEO Matthew Warren said. “This funding will help unlock the huge potential in these emerging technologies, including the $26 million added exclusively for geothermal energy.” Mr Warren said by reducing the cost of new technologies, as well as leverage finance from the private sector and state and territory governments, the grants will facilitate the exploitation of Australia’s abundant renewable energy resources. The Australian Centre for Renewable Energy will administer the program until the $3.2 billion Australian Renewable Energy Agency (ARENA) is established as part of the Government’s Clean Energy Future package.

with good maintenance of the water mains, it has proved possible to cut per capita water consumption over the last 20 years. Today 200 companies employ 35,000 people in the Danish water sector and from 1995–2009 Denmark’s export share in the water area was about double the EU average. Some of these companies will be part of an official Danish trade delegation ‘State of Green – Join the Future – Think Denmark’ which is planned for Australia (Sydney and Melbourne) from 21–24 November 2011. Approximately 40 Danish companies within the target sectors of Smart Cities (for example, water, waste, urban planning, sustainable living), Renewable Energy and Food and Food Technology are expected to participate. To register your interest in meeting these and the rest of the trade delegation, please contact the Royal Danish Embassy in Canberra. Email: cbramb@um.dk or phone: 02 6270 5333.

Danish Technology for a Thirsty World Denmark is among the countries that are the most favoured with water resources. Copious quantities of rain, combined with favourable geological conditions, mean that almost the entire country’s water consumption can be met by extracting groundwater that requires nothing but filtering and oxygenation to make it ready for use. However, moving, purifying and treating water all requires energy and ever since the oil crisis hit Denmark in 1974, the country has succeeded in freeing itself from what previously seemed an inescapable law – that per capita water consumption increases year after year. By combining campaigns to save water

Amendment The article “Alliances in the Water Section”, which featured in the August 2011 edition of Water Journal, made reference to the Murrumbidgee Infrastructure Modernisation Program. This is, in fact, an alliance between not only Murrumbidgee Irrigation and John Holland, but also GHD and UGL Infrastructure. The alliance budget is currently $110 million, plus additional works with an undefined budget at present.

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KASA Redberg will be running it’s final round of public seminars for 2011 in November and December. These seminars will be the ever popular “Pump Fundamentals” and “Liquid Piping Systems Fundamentals”. Both seminars are of two days duration. About These Seminars The information presented in “Pump Fundamentals” and “Liquid Piping Systems Fundamentals” includes: Pump calculations, pump types, sizing, selection, installation, maintenance, pipe and fittings selection, pipe sizing, pipeline materials and operation, wall thickness calculations, valves, instruments, drafting, relevant codes and standards and much more. Discounts apply for early registrations, dual seminar bookings and multiple registrations from the one organisation. We can also run these seminars at your own workplace or customise them to suit your needs. We have also provided customised pump/pipeline seminars to many organisations involved in the water and wastewater sector, mining and minerals processing etc including consultants and public utilities. Who Should Attend These seminars are designed specifically for those involved in the design, management and/or operation of pumping and liquid piping systems. Project Engineers, Process Engineers, Design Engineers, Sales Representatives and Project Managers would all benefit from the information presented. Specific examples, design calculations and hardware selections are included from industries such as: Mining/minerals processing, industrial water treatment, municipal water/wastewater, petro-chemicals, marine and heavy manufacturing. Seminar Materials For each seminar, all attendees receive:

Training Manual: A reference manual comprising theory, worked example problems, tables and charts, illustrations etc based on the training seminar outline. All KASA Redberg training manuals have been designed to be a valuable future resource for the office, workshop, factory or plant.

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industry news Rainwater Harvesting Group Reforms The Rainwater Harvesting Association of Australia (RHAA) is the reformation of the Australian Rainwater Industry Development group (ARID) with a new name, new approach, enthusiastic new committees, and a new plan for future direction. Committee chairperson, Colin Nash, believes the name change better reflects the role of the Association and its focus on all aspects of rainwater harvesting.

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“The industry has come on in leaps and bounds over the past few years. With the new committee and new focus I believe we will continue to ensure that rainwater harvesting is a critical element of alternative water solutions into the future and help steer it in the right direction,” says Mr Nash. The Association provides networking opportunities for companies, water authorities, trade associations, governments, universities, academics and further stakeholders that have a keen interest in fostering the growth of the industry. The RHAA encourages organisations to become a member and participate in the development of a strong and vital rainwater harvesting industry. The rainwater harvesting industry within Australia is worth an estimated $500 million per annum and will continue to grow as one of a suite of sustainable water solutions for Australia well into the future. For more information and how to become a member, please visit: www.rainwaterharvesting.asn.au.

Health Groups Prescribe 4000GL Water for the Murray-Darling Basin The health of communities in the Murray-Darling Basin depends on a sustainable and scientifically based approach to the restoration of environmental flows to the basin, says the Climate and Health Alliance (CAHA).

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“The current debate around water in the Murray-Darling has failed to consider the human health implications of a failing river system,” CAHA Convenor Fiona Armstrong said. The coalition of more than 20 health organisations are part of the Voices for the Murray Darling alliance, which is calling for the restoration of environmental flows that are based on credible science. The alliance is seeking the return of at least 4000GL per year to the basin in environmental flows, a volume cited by Australia’s leading environmental scientists as the minimum required to restore river ecosystem health. “Restoring the health of the Murray-Darling will require changes in the use of water,” Ms Armstrong said. “As health groups, we want to see communities assisted to adapt to sustainable water use, and a process undertaken to support the establishment of secure economic futures for affected communities. However, only a sustainable river system will support communities and local economies and health. It is vital that a national plan for water management reflects the reality that a healthy community and a healthy economy are entirely dependent on a healthy ecosystem, not the other way round.”

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awa news SWWS Network Advises on Woodfordia On-site Sewage Treatment Plant The Queensland Folk Federation presents a range of events at its Woodfordia site on the Sunshine Coast Hinterland, attracting thousands of visitors a year. The organisation searched for years for the optimum solution for its fluctuating wastewater generation before approaching members of the Small Water and Wastewater Systems (SWWS) Network. This article was provided by SWWS Network members Ben Kele (Director, Midell Water), Jordi Bembridge (Research Officer, Midell Water) and Ross Percival. Woodfordia is a special events venue operated by the Queensland Folk Federation (QFF). The site is used for music and cultural events such as the Woodford Folk Festival, The Dreaming, The Planting and, in recent years, Splendour in the Grass. The Woodfordia site comprises an area of 146 hectares and was previously a dairy farm. It has undergone extensive revegetation programs and rehabilitation works, with 44 permanent amenities blocks (showers and toilets), over seven kilometres of sewer and eight pump stations having been installed.

Figure 2. Woodford Treatment Plant generation patterns. All the events held at Woodfordia produce wastewater, which is now treated onsite at the Woodfordia Wastewater Treatment Plant. The QFF decided to move from a pump-out wastewater management strategy to a decentralised treatment system for several reasons. An independent carbon budget on the Woodfordia site found that 11% (104.625 tonnes of CO2-e) of the total greenhouse gas emissions were related to the energy required to transport the untreated wastewater to the nearest suitable sewage treatment plant. Also, a pump-out solution for Woodfordia did not provide an environmentally and economically sustainable solution. The volumes involved required over 100 truckloads per day during the big events. It was expensive, costing over $300,000 per year, and was heavily reliant on centralised council plants to receive the wastewater for treatment. If the nearest STP was overloaded, the wastewater needed to be taken to another STP further away, adding to the costs. Woodfordia was also losing recyclable water that could be reused onsite for revegetation and dust suppression. The untreated wastewater variations in flow are not the only concern at Woodfordia; the raw wastewater is also quite ‘strong’. This is a result of the water-efficient infrastructure, no washing machines, and the festival lifestyle with plentiful licensed venues and temporary restaurants. In Table 1, selected untreated wastewater characteristics at the 2010 Splendour in the Grass Festival are shown. With the large variations in flow and the non-typical domestic wastewater, a standard continuous flow biological treatment plant was unfeasible. A connection to the nearest centralised STP had been deemed economically unfeasible due to the pipeline construction costs and associated head-works charges.

Figure 1. An aerial view of the Woodfordia site during the 2009/2010 Woodford Folk Festival. The main event is the annual Woodford Folk Festival (WFF). This six-day music and cultural event is held over the New Year period and attracts upwards of 2,500 performers and presenters in 20 venues onsite, with approximately 125,000 people attending the festival over its duration.

Midell Water designed, constructed and operates a batching decentralised STP at the Woodfordia site. The system has an average treatment flow-rate of 12L/sec; with a maximum treatment flow-rate of 20L/sec obtainable if required. The system relies on mechanical and chemical treatment at the start of the chain and biological treatment at the end of the chain to allow batching flexibility not achieved by conventional plants.

Table 1. Selected untreated wastewater characteristics at the 2010 Splendour in the Grass Festival.

Woodfordia is also home to The Dreaming, an annual festival held in June that celebrates and showcases indigenous arts, performances and culture from Australia and around the world. It attracts approximately 25,000 people in attendance over the four-day event. Meanwhile, the revegetation of Woodfordia continues every year with the annual weekend festival, aptly titled The Planting. Splendour in the Grass, a three-day music festival traditionally held in Byron Bay with 17,000 attendees, was held at Woodfordia in August 2010 and July 2011. The move allowed for a huge 35,000 people to attend, with an additional 5,000 support staff and performers.

Analysis

Average

Na mg/L

138.25

Total P mg/L

44.45

Ortho P mg/L

25.85

NOX-N

0.31

Because it’s only used for special events, there are large fluctuations in the wastewater generation patterns at the site. Figure 2 shows the wastewater generation patterns for 2010.

Total N

400.5

TS mg/L

1469

32 SEPTEMBER 2011 water

pH

8.6

EC µS/cm

3050

COD mg/L

1456

NH3-N

307

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awa news The wastewater is then pumped to the first section of the treatment chain, which consists of two 175kL baffled sludge tanks. This removes solids and allows for TSS, BOD, COD, TN and TP reductions. Water leaving the clear water zone is dosed with a flocculent chemical with colour removal ability before it reaches the 1.3ML balance and aeration tank. This tank allows a large storage capacity and aerates the water with four venturi aerators. Water is then gravity-fed into a pump well where the water is dosed with hydrogen peroxide to provide disinfection, colour and odour removal, as well as BOD and COD reduction. The water is then passed through one of six Zetos filters, which contain zeolite, activated carbon and a fine garnet. The Zetos filter into another pump well where the water is dosed with the flocculent chemical again.

The effluent then travels through a fine sand and garnet filter and an additional granulated activated carbon filter. A final disinfection stage combining ultraviolet and ozone is then employed. The water is released in the main storage dam, where it is aerated to maintain water quality. It is then released into a series of wetlands, where it undergoes “naturalisation”. The final water quality of the wetland water is suitable for irrigation or other beneficial reuse. The treatment plant has been operational since 2009 and has successfully treated the wastewater from seven different festival events. The Queensland Folk Federation is hopeful that with the installation of the decentralised STP Woodfordia can become a major festival precinct within Queensland and set a standard of environmentally friendly operation for other festival venues to strive to achieve.

Small Water and Wastewater Systems: Principles for Success There is a growing awareness of the role Small Water and Wastewater Systems (SWWS) can play in the provision of water, wastewater and stormwater services. More importantly, there is increased awareness that large, centralised approaches are not always effective or affordable. Notwithstanding, it is important to recognise that a decentralised or SWWS approach (like anything) is simply another tool in the water management toolbox and cannot be all things to all people. The SWWS Specialist Network Committee has put together the following principles for successful application of SWWS for consideration by AWA members. • Successful SWWS projects involve professional centralised management of decentralised infrastructure. Centralised management of decentralised infrastructure is successfully practiced in many industries. Regulatory and institutional barriers to adoption of this principle in the water industry need to be removed. This removes uncertainty associated with ad hoc management reliant on property owner involvement and substantially reduces risks associated with decentralised systems. This will require adaptation and capacity building by government and water utilities alike. • Successful SWWS projects adopt a fit-for-purpose approach to technology selection and end use. This principle is fundamental to the success of decentralised water systems. It should not come as a surprise that the economic viability of small-scale advanced water treatment to supply high value demands (e.g. potable, residential non-potable) is often limited. Opportunities for local recycling should focus on meeting lower risk demands that enable adoption of lower energy technologies requiring limited day-to-day supervision, or which can be for the most part adequately managed remotely. • SWWS projects need to be evaluated within an integrated, holistic framework that considers benefits and life-cycle costs beyond $/kL to supply. SWWS are significantly more adaptable, require smaller step-wise upgrades (less redundancy needs to be built in) and can deliver risk management benefits (e.g. Christchurch following the earthquake). They can also create opportunities for deferring and avoiding centralised infrastructure upgrade costs. The major benefits of decentralised systems are commonly realised over the life cycle of the system, as it is most often in operating costs rather than capital costs that the greatest differentiation between centralised and decentralised is identified. • SWWS projects need to be compared to centralised approaches on a level playing field. Why should decentralised/SWWS approaches need to meet more stringent performance criteria, costs objectives and levels of service than more conventional options? Large-scale conventional systems are not expected to be perfect, low-cost and 100% proven prior to implementation. Similarly, claims that large-scale approaches such as desalination are not energy-intensive where green energy is used can equally be assigned to any technology. It still costs money to produce that energy. Furthermore, familiarity with centralised systems has historically resulted in costs being underestimated at the feasibility stage (particularly operating costs), while lack of familiarity with SWWS/decentralised systems is often compensated for by overcosting or the inclusion of unnecessary and unequal contingency costs. Particularly in Australia, where there is a very limited knowledge base of decentralised systems, this mitigates against decentralised systems as they are often considered high risk and of limited cost benefit, when in actual fact, a substantial pool of evidence from the use of decentralised systems overseas demonstrates just the opposite. • For the real benefits of decentralised systems to be enjoyed, the industry in Australia needs champions and examples of operating systems. Currently there is hesitation on the part of water authorities as they lack familiarity with decentralised systems and feel comfortable with centralised systems. Courage is required to take the first steps, but once operating systems can be evaluated the benefits will readily become apparent and the tide will begin to turn. Adoption of adversarial (centralised versus decentralised) approaches to urban/peri-urban water management is counterproductive from both directions. The Committee believes that small and decentralised systems should not be implemented without a rational environmental, social and economic basis. However, we equally believe that SWWS present a valuable opportunity to address a number of challenges facing the industry and, as such, should not be discounted without being rigorously and equitably compared to more centralised solutions. If you are interested in finding out more about the SWWS Specialist Network, please visit the webpage at: www.awa.asn.au/ SWWS.aspx or contact the committee at networks@awa.asn.au

water

SEPTEMBER 2011 33


awa news Source Management to Reduce

What Contributes Salinity in Recycled Water?

Salinity in Recycled Water

Various domestic, commercial and industrial activities at the source of wastewater generation contribute towards elevated levels of salt in wastewater. The treatment processes adopted in a typical wastewater treatment plant (except reverse osmosis) cannot remove the majority of the dissolved salt from the wastewater stream. Hence, in most cases, the salt levels in recycled water are relatively higher than most sources of potable water. This is highlighted in Table 1. As shown in the table, the salt concentrations in recycled water could be significantly higher than drinking water levels. In addition, higher levels of pH and certain anions and cations can also be observed in the recycled water.

This article was prepared by Muhit Rahman and Dharma Hagare, University of Western Sydney, with contributions from the AWA Source Management Specialist Network Committee. Source management is now an integral part of the vocabulary (replacing ‘trade waste management’) in the overall wastewater management area. This includes the identification and monitoring of contaminants with a view to their reduction or elimination before they enter the sewer system, which is critical in order to protect the sewage collection infrastructure, sewage workers, treatment processes, effluent quality and the receiving environment. Source management, in particular, is gaining enormous significance in the context of recent emphasis on the reuse of treated wastewater and biosolids.

Sources of Salinity in Wastewater The major sources of salinity in wastewater are industry, commercial operators and domestic household. Sources of salinity in recycled water depend on the original composition of the municipal water supply and the nature of residential

Table 1. Typical salt concentrations in recycled water and their comparison with drinking water standards. Recycled water Range

Average value

Drinking water standard

Electrical conductivity, dS/m

0.51-2.7

1.53

0.1

Total dissolved solids (TDS), mg/L

358-1800

1054.86

<500

Parameter

pH

7.06-9.6

8.12

6.5-8.5

Na+, mg/L

84.9-350

173.64

180

Cl-, mg/L

43.9-564.4

284.70

250

References Bakopouloun et al. 2011, Smith et al. 1996, Kang et al. 2007, Adrover et al. 2010, Dikinya & Areola 2010, Tarchouna et al. 2010, Aiello et al. 2007, Kalavrouziotis et al. 2009, Goncalves et al. 2007

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awa news and commercial communities contributing to the wastewater, and vary according to geographical location. To highlight the domestic contribution towards salinity, salt inputs for four different geographical locations in Australia are listed in Table 2. As shown in the table, salt contributions from domestic sources far exceed the natural content of salt in the potable water. Some of the most obvious sources of salt in wastewater include (adopted from CRD, 2011): • Dry cleaning/laundry • Domestic/commercial kitchens

• Specific industrial discharges In the case of urban contribution of salinity, when the water is used in domestic or commercial property, chemicals containing sodium are used for washing clothes and utensils, and in food preparation (Patterson, 2004). This salt, along with other household waste, goes to sewer and, finally, to the treatment plant. While most of the organic matter is removed by various wastewater treatment processes, the majority of salts pass through the wastewater treatment systems unaffected.

Effect of Higher Levels of Salt in Recycled Water on its Application

• Laboratories • Automotive repair

Several studies have been carried out on the effect of use of recycled water on agricultural land. According to AlNakshabandi et al. (1997), the problem associated with the use of treated effluent for irrigation is salt accumulation in soils; salts accumulate on the soil surface and along the soil profile

• Breweries and wineries • Carpet cleaning • Dental clinics • Food services

• Recreational facilities

• Photographic imaging

Table 2. Contribution to salinity from domestic sources in four major cities in NSW considering 5ML discharge/day (Patterson, 2004).

• Printing industry

Location

• Fish processing industry

Coffs Harbour

• Textile industry

Armidale

• Hide & skin processing • Vehicles wash

36 SEPTEMBER 2011 water

Input from domestic source (tonnes NaCl/year)

Input from potable water source (tonnes NaCl/year)

Total (tonnes NaCl/year)

306

32

338

203

127

330

Moree

246

14

394

Dubbo

306

283

589

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awa news at the peripheries of the wetted zone. Dikinya & Areola (2010) reported build-up of salts in the agricultural land due to longterm use of recycled water. After three years of irrigation with recycled water, the electrical conductivity in soil increased from 105 to 235 µs/cm (about a 123% increases), cation exchange capacity of soil decreased from 9.21 to 8.61 cmol/kg and Na+ increased from 2.95 to 5.75 meq/100g of soil. Also, recycled water use has an impact on saturated hydraulic conductivity of soil. In one study, after two years of irrigation using recycled water, the hydraulic conductivity was reported to have decreased from 48 to 30.73 mm/hr (Gonçalves et al., 2007).

Change of practice • Choose liquid laundry detergents, or concentrated powder • With dishwasher and laundry detergents use half the recommended dose recommended, as the town water supply is typically soft • Minimise the use of salt and other food additives in cooking • Avoid using domestic salt-based water softener • Use organic compost rather than chemical fertiliser for home nursery Implementation of the 3Rs • Replace (products with an environmental friendly substance) • Reduce (the use of products contributing salinity) • Recycle (the household leftovers) By-laws

Treated wastewater is frequently used for agricultural irrigation. These studies clearly indicate that for long-term viability of using recycled water for irrigation, it is necessary to control the salt in the recycled water. Moreover, it may be more efficient to control the salt at the source; ie, the point of generation of wastewater.

• Segregate and separately manage wastewater that potentially consists of higher levels of salt. • Prohibition may be considered for certain products not to be discharged in the sewer.

Source Control Measures

• Monitoring should be carried out daily, weekly, fortnightly or monthly to check the compliance at the source.

Effective source control measures are crucial for the control of salinity in recycled water. The success of any control measure demands the active participation as well as willingness of the stakeholders. Some source control measures for domestic household are (GMF 2011, Fresno City Council 2011):

Implementation of the above control measures at the source will no doubt be the most economical way of minimising the salt concentrations in the recycled water, thereby increasing the more widespread applications of recycled water. Therefore, the efficient use of a resource starts at the beginning of the cycle.

Education and awareness through:

For more information about the Source Management Specialist Network, please visit: www.awa.asn.au/LTW.aspx or email: sourcemanagement@awa.asn.au

• Council or dedicated website • Flyers with utility bill • Posters, newsletter, media • School visits • Community and environmental groups Conservation • Reduced use of cleaning chemicals

References Adrover M, Farrús E, Moy G & Vadell J, 2010: Chemical properties and biological activity in soils of Mallorca following twenty years of treated wastewater irrigation. Journal of Environmental Management, http://www. sciencedirect.com/science/article/pii/S0301479710002653. Aiello R, Cirelli GL & Consoli S, 2007: Effects of reclaimed wastewater irrigation on soil and tomato fruits: A case study in Sicily (Italy). Agricultural Water Management, 93, pp 65–72.

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awa news Bakopoulou S, Emmanouil C & Kungolos A, 2011: Assessment of wastewater effluent quality in Thessaly region, Greece, for determining its irrigation reuse potential. Ecotoxicology and Environmental Safety, 74, pp 188–194. CRD (Capital Regional District) website: www.crd.bc.ca, viewed on August 5, 2011. Dikinya O & Areola O, 2010: Comparative analysis of heavy metal concentration in secondary treated wastewater irrigated soils cultivated by different crops. International Journal of Environmental Science and Technology, 7, pp 337–346. Fresno City Council website: www.fresno.gov – viewed August 5, 2011. GMF (Green Municipal Fund) website, viewed: August 5, 2011, Report, Wastewater source control – A best practice by the National Guide to sustainable municipal Infrastructure, Issue 1, March 2003, Federation of Canadian Municipalities and National Research Council, http://gmf.fcm.ca/files/Infraguide/storm_and_wastewater/waste_water_ source_control.pdf Gonçalves RAB, Folegatti MV, Gloaguen TV, Libardi PL, Montes CR, Lucas Y & Dias CTS, 2007: Hydraulic conductivity of a soil irrigated with treated sewage effluent. Geoderma, 139, pp 241–248. Kalavrouziotis I, Koukoulakis P, Papadopoulos A & Mehra A, 2009: Heavy metal accumulation in Brussels sprouts after irrigation with treated municipal waste water. Journal of Plant Interactions, 4, pp 41–48. Kang MS, Kim SM, Park SW & Lee JJ, 2007: Assessment of reclaimed wastewater irrigation impacts on water quality, soil, and rice cultivation in paddy fields. Patterson RA, 2004: A resident’s role in minimising nitrogen, phosphorus and salt in domestic wastewater, in Tenth National Symposium on Individual and Small Community Sewage Systems Proceedings, Kyle R Mankin (Ed) held in Sacramento, California 21–24 March 2004. American Society of Agricultural Engineers, pp 740-749. Smith C, Hopmans P & Cook F, 1996: Accumulation of Cr, Pb, Cu, Ni, Zn and Cd in soil following irrigation with treated urban effluent in Australia. Environmental Pollution, 94, pp 317–323. Tarchouna LG, Merdy P, Raynaud M, Pfeifer, HR & Lucas Y, 2010: Effects of long-term irrigation with treated wastewater. Part 1: Evolution of soil physico-chemical properties. Applied Geochemistry, 25, pp 1703-1710.

Australian Expertise Helps Implement Water Safety Plans in India The realisation of health, operational and financial benefits accrued through Water Safety Plan (WSP) implementation has contributed to a growing evidence base that they are the most effective means to consistently providing safe drinking water. Australian water utilities have been pioneering the effective implementation of proactive risk management plans (or WSPs) for drinking water supplies since the late 1990s. Concerted efforts from multi-lateral agencies led by the World Health Organisation (WHO) to promote WSPs and provide capacity building for water utilities, regulators and other

stakeholders have led to an increasing number of WSPs being implemented in developing countries around the world. In some regions, there is a genuine opportunity for WSP implementation through peer-to-peer learning mechanisms. WASH (Water, Sanitation and Hygiene in Developing Communities) is one of AWA’s Specialist Networks that promotes knowledge-sharing between Water and Sanitation specialists for the purpose of assisting developing communities. The network provides a forum to facilitate the sharing of knowledge and access to appropriate technologies and expertise as well as the promotion of water supply, sanitation and hygiene initiatives to AWA members and the wider community. Asoka Jayaratne, Water Quality Specialist at Yarra Valley Water and a WASH Committee Member, has been working with the WHO as a voluntary consultant to implement WSPs in urban water utilities in Vietnam, the Philippines and India. Yarra Valley Water is generously providing in-kind support by contributing Asoka’s time for WHO activities. In July 2011, Asoka travelled to the City of Nagpur in India to conduct a five-day workshop to kick-start the WSP development for the Nagpur Municipal Corporation (NMC). WHO intends to use this WSP as a model for other Indian water utilities. Nagpur workshop was also a forum for hands-on training to a group of over 30 public health officials, consultants and water utility personnel from India, Bhutan, Nepal, Indonesia and Sri Lanka. The workshop focused on: • A day’s training on the WSP concepts; • A day trip to a WSP pilot area; • The completion of hazard identification from catchment to consumer; • A risk assessment, leading to the preparation of the WSP for the pilot area; and • Training of trainers and capacity building.

A Water Safety Plan workshop in progress.

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awa news common. Illegal connections bring in an additional risk of backflow and backflow prevention is almost non-existent in NMC. Completion of hazard identification was a key outcome of the workshop. Applying the knowledge gathered in the workshop, the NMC will complete the WSP in the coming months with assistance from NEERI. Focus of the WSP implementation will then shift to prioritisation of improvement projects identified in the WSP such as catchment management, treatment plant upgrades, leakage reduction, water mains replacement and introducing continuous (24/7) supply. These improvements will require substantial investment and inevitably take several years to implement. WHO will provide further assistance to monitor the effectiveness of the WSP implementation in coming years.

A water collection pit (and the only drinking water tap) next to the sewer manhole at the front of a slum dwelling.

If you have any queries about the WASH Specialist Network, please contact networks@awa.asn.au or visit the webpage at www.awa.asn.au/WASH.aspx

Challenges in Supplying Safe Drinking Water to Nagpur

Easier Access to Trade Waste Training

In many developing countries water quality objectives are lost when confronted with water availability issues. While there is a push to increase access to drinking water in urban areas of India, often water quality supplied to the end users remains poor due to recontamination during distribution of the treated water. Intermittent water supply combined with higher unaccounted for water (leakage) is a major contributing factor to recontamination.

Trade Waste Management [Source Management] is the management of industrial and commercial wastewater entering the sewerage system. The management of wastewater is a complex and critically important task for the long-term management of a water utilityâ&#x20AC;&#x2122;s assets, sewer worker health, biosolids, recycled water quality and the ecological health of receiving waters in the environment.

The City of Nagpur is situated near the geographical centre of India in the State of Maharashtra and the NMC provides water and sewerage services to 2.5 million people. The pilot water supply area selected for the WSP implementation is scheduled to receive a reticulated 24/7 water supply by 2013. The NMC intends to use the WSP for a paradigm shift from quantity to quality and prioritise improvements based on risk to public health and secure capital investments through private-public partnerships. The strong commitment shown from the Mayor of the City Council through to the water supply operator was a key factor in WHO choosing Nagpur City to implement a model WSP for India. WSP implementation in Nagpur is facilitated by the National Environmental Engineering Research Institute (NEERI).

Trade waste became a part of the overall management of our sewer systems in the late 1980s, when commercial and industrial users in the sewer networks were asked to take responsibility for the management of the wastewater discharged from their premises. This was the point at which the occupation of Trade Waste Officer was born.

Catchment management is a major challenge in WSP implementation in Nagpur, because currently there are very few or no catchment management controls in place. Uncontrolled access leads to cattle roaming in some catchments almost on a daily basis. Also, the potential for contamination from sewage and waste from human settlements within some catchments is high. The need for a well constituted stakeholder communication program and a catchment management strategy were identified as key control measures during the workshop. Water treatment plants in Nagpur are managed by private operators and these appear to be satisfactorily operated and maintained to produce water meeting water quality standards. However, recontamination of treated water in the distribution system and at consumersâ&#x20AC;&#x2122; premises is a common occurrence. The lack of storage tank maintenance in the distribution system also leads to recontamination. Non-revenue water is around 60%. Leaking water mains are a perfect avenue for contaminants to enter water mains during low or no pressure periods. Poor water storage and collection practices at consumer premises reintroduce contamination from leaking sewers and surrounding ground at the point of use. This is prevalent in slum dwellings where illegal connections are

40 SEPTEMBER 2011 water

During the recent period of low rainfall, a greater focus was directed at what is being discharged into the sewer system. As commercial and industrial activities became more water efficient, the concentration of pollutants increased and the sewerage in the system became a source of recycled water for innovative systems such as sewer mining. It became more important for urban water utilities to manage the sources of pollutants being discharged and this forced them to look at their business from a holistic perspective. This included not only the business activities, but the entire sewer catchment. Trade Waste Officers have had few training options in the past and mostly training has been done on the job. In many cases, trade waste has not been their only task, particularly in regional and remote water utilities in Australia. More than 10 years ago, the need for training was identified by practitioners in the Australian Water Association (AWA) Specialist Network on trade waste, which led the way towards the development of an appropriate and nationally supported course on trade waste. Over the past three years, the Water Services Association of Australia (WSAA) has been working with Government Skills Australia, the industry skills council responsible for the qualification framework for water, to develop the nationally recognised qualification NWP 40107 Certificate IV in Water Operations (Trade Waste). The qualification has been structured to ensure it meets the needs of those working in a trade waste context, and this course is recognised by Australiaâ&#x20AC;&#x2122;s largest water utilities as a key requirement for those working in the trade waste field. It will support the work of supervisors and technical experts responsible for the management and

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awa news implementation of trade waste policies, plans and approvals, as well as those coordinating and monitoring source control, commercial/industrial wastewater treatment and discharge, or wastewater collection systems.

BECA; Carmel Krogh, Shoalhaven Council; Paul Macinante, SKM; Katherine Marshall, BECA; Kate Miles, AECOM; Ivan Reolon, Aquatec-Maxcon; Tim Summers, AECOM; Mark Trembath, ITT Water & Wastewater; and Justin Watts, CH2M Hill.

To assist industry to access this specialist qualification, AWA and WSAA are pleased to announce a nationally coordinated approach to its delivery. Following a selection process, two large registered training organisations have been identified to offer the program Australia-wide via a range of flexible delivery options. Expressions of Interest (EOI) opened on 1 August for a course commencing in October 2011 and to date there has been a very pleasing response from industry.

Victoria Branch News

So why is this initiative important to the water industry generally? Access to a nationally recognised qualification will allow the transportability of trade waste skills from region to region and state to state around Australia. This initiative helps to build organisational capacity and capability within a recognised framework. It increases the knowledge of the sector and thus provides better outcomes for industrial and commercial businesses that interact with water utilities. For some years, water industry training has existed for water treatment plant operators. We now have on offer a specialist trade waste training program. Don’t miss this opportunity for your trade waste workers to gain a nationally recognised qualification.

Committee News The Victorian Branch held its first committee meeting for 2011–12 in August and is delighted to advise that: • Peta Maddy was re-elected as President for a two-year term. The President’s role was previously a one-year term; however, this was recently realigned to the cycle for the election of Board Directors. Peta’s energy and drive has been a wonderful asset to the Branch during 2010–11. • Therese O’Brien was elected as Vice-President and 2nd SAC Representative (Therese was Chair of the Program Sub-Committee last year). • Stewart Burn was re-elected as Treasurer, following a very successful first term in 2010–11.

For further details contact Petra Kelly, email: pkelly@awa.asn. au; phone: 02 9467 8436 or go to: www.awa.asn.au/Certificate_ IV_Water_Operations_Trade_Waste.aspx

Please “Like” Us on Facebook The Australian Water Association now has a Facebook page. Simply “Like” the page to get information on the latest news and upcoming events in the water industry. www.facebook. com/australianwaterassociation.

NSW Branch News 2011 Heads of Water Gala Dinner & New Committee Announced The NSW Branch recently held its 2011 Heads of Water Gala Dinner and introduced its newly elected committee, whose members are as follows: NSW Branch President – Murray Thompson, Port MacquarieHastings Council; Vice President – Erin Cini, Element Solutions; NEWSdrop Editor – Karen Eaton, UGL Infrastructure; and committee members – Emma Pryor, MWH; Graham Attenborough, SCA; Tony Cartwright, Sydney Water; Ian Chase,

Top row: Gail Reardon, Don Williams, Stewart Burns, Geoffrey Frost, Bruce Hammond, Luke Welsh, James Currie, Ben Jensen, Kate Simmonds. Bottom row: Therese O’Brien, Chris Corr, Peta Maddy, Deirdre Rose, Henry Mallia, David Mawer (not pictured, Andrew Chapman and David Kirby).

Tasmania Branch News AWA Tasmania Galah Debate 2011 Back for another year, the Galah Debate continues to grow in popularity among members, corporate partners and the local water sector. This year Gary Ingram from Team South has handed the captaincy to Aniela Grun. Andrew Saggers from Team North has been busily recruiting, desperate to have the Vinidex trophy returned to the North. The debate will be held at Wrest Point’s Derwent Room on 22 September 2011. For more information email: tasbranch@awa.asn.au

Merger Creates New Body

Attendees at the 2011 Gala Dinner.

42 SEPTEMBER 2011 water

On 1 July 2011, Tasmanian Irrigation was created through the merger of the former Rivers and Water Supply Commission, Tasmanian Irrigation Schemes and Tasmanian Irrigation Development Board. The assets, liabilities and responsibilities of the three former entities now reside with Tasmanian Irrigation, a state-owned company responsible for managing the Meander Valley and Coal River irrigation schemes, and for taking a suite of new projects in 13 regions of Tasmania through the development, construction and operational stages. AWA Tasmania welcomes Tasmanian Irrigation as our newest Corporate Member.

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awa news AWA EVENTS CALENDAR This list is correct at the time of printing. For up-to-date listings and booking information please check the AWA online events calendar at: www.awa.asn.au/events September

QLD Monthly Technical Meeting – Trends in the Management of Biosolids, Brisbane, QLD

Wed, 14 Sep 2011

SA Technical Meeting, Adelaide, SA VIC Technical Breakfast – Pricing, regulation, water markets & trading, Melbourne, VIC SA YWP Technical Tour, Adelaide, SA Galah Dinner & Debate, Wrest Point, TAS YWP (VIC) Working with People Workshop, Melbourne, VIC TAS Technical Seminar, South Tasmania, TAS ACT Student Awards Presentation Evening, Canberra, ACT

Wed, 14 Sep 2011 Tue, 20 Sep 2011 Wed, 21 Sep 2011 Thu, 22 Sep 2011 Thu, 22 Sep 2011 Tue, 27 Sep 2011 Wed, 28 Sep 2011 October

Wed, 12 Oct 2011 Mon, 17 Oct 2011 Mon, 17 Oct 2011 Tue, 18 Oct 2011 Wed, 19 Oct 2011 Thu, 20 Oct 2011 Fri, 21 Oct 2011 Mon, 24 Oct 2011 – Wed, 26 Oct 2011 Tue, 25 Oct 2011 Tue, 25 Oct 2011

November

Wed, 02 Nov 2011 – Thu, 03 Nov 2011 Fri, 04 Nov 2011 – Sat, 05 Nov 2011 Tue, 08 Nov 2011 – Wed, 09 Nov 2011 Thu, 17 Nov 2011 Sat, 19 Nov 2011 Thu, 24 Nov 2011 Fri, 25 Nov 2011 Fri, 25 Nov 2011

New Members AWA welcomes the following new members since the most recent issue of Water Journal:

NEW CORPORATE MEMBERS NSW Corporate Gold Yokogawa Australia Pty Ltd Corporate Bronze CST Industries Inc. Corporate Silver Peel Water Pty Ltd Taggle Systems

NT Corporate Bronze Department of Construction & Infrastructure (NT)

QLD Corporate Silver Akwa-Work Pty Ltd

TAS Corporate Bronze Tasmanian Irrigation

VIC Corporate Silver Rain Gardens Australia T/A RGA Optimal Management

44 SEPTEMBER 2011 water

QLD Monthly Technical Meeting, Brisbane, QLD IWM Summit, Melbourne, VIC VIC Branch 2011 Awards, Melbourne, VIC WA National Water Week Seminar: Recycling with GWRT Site Visit, Perth, WA Monthly Technical Meeting, Brisbane, QLD ACT Branch BBQ, Black Mountain, ACT Water In the Bush, Darwin, NT 14th NSW Engineers-Operators and Regional Conference, Byron Bay, NSW SA Technical Meeting, Adelaide, SA TAS Technical Seminar, South Tasmania, TAS 2nd Annual National Water Leadership Summit, Hyatt Canberra, ACT QWater’11 Regional Conference, Novotel Twin Waters, Sunshine Coast Contaminants of Concern in Water Specialty Conference IV, Sydney, NSW YWP (VIC) PD Seminar – Mentoring Breakfast, Melbourne, VIC SA Awards Dinner, Adelaide, SA Gala Dinner & 2011 TWEMA Presentation, Hobart, TAS WA Undergraduate Water Prize Presentation, Perth, WA WA Water Awards 2011 Gala Dinner, Perth, WA

WA Corporate Bronze Dewatech

NEW INDIVIDUAL MEMBERS ACT W. Chadwick, N. Chan, M. Ross, A. Piani NSW E. Rizk, D. Mitchell, B. Metman, F. Rodrigo, G. Mansfield, J. Uy, G. Fox, J. O’Gorman, J. Biro, J. Chan, J. Surindrawarige, J. Vojkovic, J. Taing, G. Gray, K. Lam, C. Andrews, C. Agnew, C. De Silva, L. Sharp, P. Nutter, R. Hartman, J. Kusters, M. Morris, M. Marston, P. Thomas, P. Edwards, M. Leszczynski, M. Kong, M. Rubcic, N. Sutton, P. Parkinson, P. Pathirana, R. Madhok, R. Bokhari, R. Patterson, R. MacKenzie, S. Sritharan, S. Guruge, L. Hiscock, S. Sakthivel, Z. Gibson, Z. Wood, C. Jayaratnam, P. Pascal, D. Lloyd, D. Foster, J. Casorzo, A. Minshull, C. Chad, B. Walker, D. Ross, D. McDade, F. Conlon, G. Douglas, R. Yip, J. Conway, S. Chae, L. Francisci, R. Gilmore, J. Liddell, H. Ma, R. Baldwin, N. Oschmann NT S. Kwan QLD P. Fraser, T. McLaughlin, S. Wohlsen, C. Bowes, S. Ayre, S. Smythe, B. Ehya, D. Field, D. Middleton, I. Roeser, N. Towner, A. Hieatt, K. Gray, I. Slape, P. Raveenthiran, G. Rettke, P. Rogers-Clark SA J. Moyse, J. Strahan, E. O’Driscoll, R. Webb, N. Robinson TAS D. Burt, H. Poortenaar, S. Krohn VIC J. Doolan, N. Duncan, C. Radford, M. O’Connell, L. Munoz, M. Stephens, S. Mustedanagic, W. Wood, B. Crawford, J. Martin, H. Gordon-Clark, K. Drzewucki, G.

Jimenez, M. Aarts, J. O’Toole, B. Mitsch, P. Diprose, S. Mahar, J. Docherty, N. Crosbie, L. Cotter WA A. Macnish, M. Riera, M. Dunlop, K. Bardot, J. Tay Overseas Y. Roman

NEW STUDENT MEMBERS QLD N. O’Shea SA C. Anderson TAS C. Harte VIC R. Cousin, U. Shrestha

YOUNG WATER PROFESSIONALS NSW A. Adeniran, R. Melville, A. Wang QLD C. Magee TAS B. Davie VIC D. Thorpe, G. Rooks, S. Jeffries, R. Buhagiar, K. Wilkinson, P. Brown, L. Wilson, R. Liu, A. Nichols, A. Harper, A. Alimein, A. Walsh WA A. Chalmers, D. Williams, R. Divita, C. Sanguinetti, S. Mounsey, K. Patel, S. Cullen, A. Barnes

If you think a new activity would enhance the AWA membership package please contact us on our national local call number 1300 361 426 or submit your suggestion via email to membership@awa.asn.au.

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conference reviews

Disinfection By-Products (DBPs) Workshop Steve E Hrudey, Jeffrey WA Charrois & Andrew Humpage Ozwater’11, which took place in Adelaide in May, featured a workshop titled Disinfection By-Products (DBPs) – Relevance to Human Health. Combined with a subsequent AWA cosponsored workshop hosted by the Curtin Water Quality Research Centre in Perth, WA, it featured contributions from six international and three Australian speakers. The workshop speakers are also contributing manuscripts on this topic to a forthcoming book, which is jointly sponsored by AWA and IWA Publishing and edited by Professor Steve E Hrudey (University of Alberta, Canada) and Associate Professor Jeffrey WA Charrois (Curtin Water Quality Research Centre). Associate Professor Charrois provided a history of DBPs in drinking water within an Australian context. The Australian drinking water industry has been near the cutting edge of DBP research developments for 35 years. Improvements in analytical methods have increased our ability to identify DBP species that were once difficult, if not impossible, to detect. Notable emerging DBP classes now being studied in Australia (as well as globally) include: N-nitrosamines, iodo-DBPs, halonitromethanes, haloamides, halogenated furanones, haloaldehydes and haloquinones. A reflection of increasing DBP interest is noted in several updates of the Australian Drinking Water Guidelines (1987, 1996, 2004, and 2011 (draft)). The Guidelines have evolved from general comments on total trihalomethanes (THMs) and no DBP guideline values (1987), through an expanded list of 23 potential DBP species (1996), to a focus on risk management with the Framework for Management of Drinking Water Quality (2004). Improved national coordination efforts are now required to evaluate the occurrence of emerging DBPs of health concern, in addition to considering transformation by-products, mixtures and the role of toxicity testing.

Utility Management of DBPs

presented Presentedatat

Stuart Krasner (Metropolitan Water District of Southern California) prepared a summary of the major and emerging issues regarding halogenated DBPs. Control of the originally regulated DBPs (THMs and haloacetic acids (HAAs)), as well as total organic carbon (TOC), had been expected to control other halogenated DBPs. However, other non-regulated DBPs have been found to increase when certain alternative disinfectants are adopted to reduce formation of THMs and HAAs. Based on expected toxicity, some non-regulated DBPs such as iodine-containing THMs, haloacetonitriles (HANs), haloketones, halonitromethanes (HNMs), haloacetaldehydes, haloacetamines and halogenated furanones are drawing attention and bringing greater scrutiny to the consequences of alternative treatments aimed at reducing regulated DBPs. Dr William Mitch (Yale University) provided a summary of major and emerging issues regarding nitrogenous DBPs. The original focus on THMs and HAAs was based on understanding that they were formed by reactions between halogenated disinfectants and natural organic matter (NOM), ie, humic materials. Because NOM contains little nitrogen, the focus on the original DBPs involved little consideration of formation of nitrogenous DBPs. However, nitrogenous organic matter from sewage effluent and from algal biomass has been found to be a precursor to a wide range of nitrogenous DBPs including N-nitrosamines, halonitriles and halonitroalkanes. The formation of more toxic nitrogenous DBPs, as noted for the non-regulated halogenated DBPs, makes the choice of alternative treatments for reducing THMs and HAAs more complicated. Professor Xing Fang Li (University of Alberta) provided an overview of a class of newly discovered DBPs, the halogenated benzoquinones (HBQs). Based on quantitative structure toxicity relationships performed by Dr Richard J Bull (MoBull Consulting, Washington) on plausible DBPs of health significance, HBQs were identified and their toxicity was predicted to be 1000 to 10,000-fold greater than THMs. Consequently, a sensitive and specific analytical technique was developed. With a reliable technique in hand, sampling was performed on raw and treated water at full scale water treatment plants and the occurrence and formation as DBPs of a series of HBQs (2,6-dichlorobenzoquinone, 2,6-dichloro3-methylbenzoquinone, 2,3,6-trichlorobenzoquinone) has been demonstrated. Studies on the cytotoxicity and DNAbinding capability of these compounds have been initiated to aid in judging the relative importance of these previously unrecognised DBPs.

Richard Walker (Water Corporation, WA) provided a utility perspective on the management of DBPs. Australian utilities face a range of treatment challenges, including: above-ground pipelines, long distribution systems, high concentrations of natural organic matter, algal blooms, and naturally elevated bromide and iodide – all of which impact on DBP formation potentials. As such, many utilities are faced with the challenge of balancing THM excursions (regulatory risk) with other public health risks that have more immediate adverse consequences (ie, pathogen risk). In the case of Water Corporation, it treats DBPs like any other hazard and attempts to manage them through the Water Safety Plan process and by establishing an acceptable operating envelope (between the THM guideline value (max) and the disinfectant dose required to meet a minimum CT-value). Operators need to “know their system” and be alert for changes in DBP concentrations as an indicator of system problems. However, a utility must never compromise disinfection, even at the risk of exceeding Professor Steve Hrudey speaking at the DBP Workshop at Ozwater’11. DBP guideline values.

46 SEPTEMBER 2011 water


conference reviews

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conference reviews DBPs and Human Health Professor Steve E Hrudey (University of Alberta) provided an overview of the strengths and limitations of epidemiological evidence regarding DBPs and human health. The types of epidemiologic studies found and their comparative value for determining causal inference were reviewed. The importance of and major difficulty with documenting individual DBP exposure was explained. The discrepancy between bladder cancer case predictions attributable to THMs by epidemiological evidence versus toxicological risk assessment was demonstrated. The major uncertainties inherent in epidemiologic evidence concerning any associations with DBPs of bladder cancer or adverse reproductive outcomes were explored. Dr Richard J Bull reviewed the experimental evidence concerning DBP-induced cancer and its relevance to human health. The main problem is that quantitative cancer risk derived from epidemiologic studies that associate bladder cancer with consumption of chlorinated drinking water is not supported by experimental data on DBPs. Descriptive animal studies can be challenging to interpret with respect to human health risk. Experimental studies provide information on the modes of action of DBPs that is critical to assigning risk to humans. For example, distinguishing between genotoxic (interactions with DNA) and non-genotoxic mechanisms makes a large difference in the derivation of health-based criteria, as evidenced by chloroform. A 70-fold less stringent criterion was derived because chloroform acts by a non-genotoxic mechanism. The importance of exploring the biochemical processes through which DBPs interact to produce adverse effects was illustrated by examining the functional features of enzyme variants that activate THMs. Based upon genotyping alone, recent epidemiological data found

presented Presentedatat

that these variants were associated with higher bladder cancer risk from chlorinated drinking water. The validity of a conclusion that this finding strengthens evidence of THMs causing bladder cancer was called into question. It is more probable that other DBPs are responsible. Dr Andrew Humpage (Australian Water Quality Centre, SA Water) provided a review of the toxicology and health risk assessment of MX (3-Chloro-4-(dichloromethyl)-5-hydroxy2(5H)-furanone). MX (for mutagen X) is produced by the reaction of chlorine with NOM during disinfection. It occurs at very low concentrations in chlorinated drinking water but is an extremely potent mutagen in bacteria, reacting with DNA to cause base substitutions and other genetic lesions. MX is less potent in mammalian cells and mechanisms not mediated by DNA may also contribute to its carcinogenicity. Mechanistic models based on MX mutagenicity have been used by all published risk assessments. Despite this common basis, they vary by over 200fold in the MX concentration proposed for drinking water. Clearly, agency regulatory policies strongly influence final guideline values. The case of MX demonstrates that risk assessment predictions do not provide an absolute determination of risk, especially when extrapolating to very low concentrations. Jessica Boyd (University of Alberta) provided an overview health risk assessment of N-nitrosodimethlyamine (NDMA) and other N-nitrosamines. NDMA is considered a probable human carcinogen that has received an increasing amount of attention over the last two decades as a DBP. Typically NDMA concentrations in drinking water are in the sub-ng/L to 10 ng/L range (parts per trillion). However, there are many notable examples of locations where drinking water concentrations can exceed 100 ng/L. Several additional N-nitrosamine species have also been detected in drinking waters. N-nitrosamines are two to four orders of magnitude more potent as carcinogens than the most common DBP classes (THMs and HAAs). Neither THMs nor HAAs are sufficiently potent or mechanistically plausible as carcinogens to account for the adverse health effects estimated in some epidemiology cancer studies. However, N-nitroso compounds, as a class, have produced tumours in every tissue type in which they have been tested. Consideration of N-nitrosamine exposures from drinking water also needs to be taken in context because it is well established that NDMA and NDMA precursors are commonly found in foodstuffs and consumer products. Moreover, endogenous formation of N-nitrosamines is predicted to dominate individual overall N-nitrosamine exposure. Occurrence data suggest that NDMA drinking water exposures represent a minor component of total human NDMA exposure. In summary, the workshop presentations revealed the current state of knowledge about DBPs in relation to human health. The reality that many, if not most DBPs, remain to be identified and that unambiguous evidence of human health impacts from DBP exposures will remain elusive means that our past and current approach of using precautionary limits to DBP exposures via drinking water is likely to remain our only viable public health policy option for some time to come.

Note to Readers The DBP working group of the NHMRC Water Quality Advisory Committee is currently formulating recommendations for revisions of the DBP factsheets in the Australian Drinking Water Guidelines. Industry personnel and regulators wishing to propose revisions are invited to contact the working group’s chair, Andrew Humpage (email: Andrew.humpage@sawater.com.au).

48 SEPTEMBER 2011 water

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conference reviews

M ade in ia l Austra

water

SEPTEMBER 2011 49


feature article

Putting a Price on Water Despite a perception that water prices are rising disproportionately, the real cost of water services as part of total household expenditure is still low for most Australian households. But how do water utilities get this message over to consumers? Written by Andrew Speers, AWA National Manager – Policy Controversy over the rising price of water and wastewater services is having a profound effect on the urban water industry. An obvious example is the decision by Gold Coast City Council and, later, Redland City Council, to pull out of Allconnex, the common water utility servicing these two local government areas, as well as Logan City Council.

for middle- and high-income families, Queensland charges were the second lowest as a proportion of household disposable income in 2007–08 (although this was a statewide view that did not separately deal with South-East Queensland, where the greatest controversy has arisen. The analysis was carried out before the most recent price rises).

The justification for the breaking up of Allconnex is price. Gold Coast City Council, in particular, feels that it can provide water services more cheaply than Allconnex – and perhaps it can. However, while the rising cost of living – and the rising price of utility services specifically – is a concern, perhaps the response is out of kilter with the actual cost of water, notwithstanding recent above-CPI price increases.

Comparison of Household Expenditures

Interestingly, the jurisdiction in which water prices had least impact on low-income families was Queensland, and

20 15 10 5 0 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10

Per cent of total household expenditure

There are several perspectives from which this issue might be viewed. In its recent draft report, Australia’s Urban Water Sector, the Productivity Commission noted that the cost of water for households is low compared to other utility services and as a proportion of total household expenditure. The Commission looked at household expenditure on water and wastewater services as a percentage of total household disposable income for three income groups: low, middle and high. It was found that in low-income areas of Sydney and Melbourne household expenditure on water and wastewater services averaged “just over 1 per cent of income, and ranged between 0.3 per cent and 4.9 per cent of income in 2005–06, assuming all volumetric costs were borne by the household and before concessions were deducted” (Productivity Commission April 2011).

Viewed alongside other household expenses, the Productivity Commission found that: “The available evidence indicates that relatively few households experience payment difficulties for water and wastewater services” (Ibid). More households, the Commission claims, have difficulty paying for energy and housing costs, as shown in Figure 1.

Water and sewerage

Energy

Housing

Figure 1. Household expenditure on selected essential services, Australia (Productivity Commission, April 2011). Of course, this graph masks the fact that the cost of utility services has been rising quickly, and that in many jurisdictions increases well above the increase in the CPI have been experienced, particularly over the past two years. For some people real pain is incurred and the water industry, economic regulators and governments will need to have in mind the social impacts of pricing decisions. Several times over the past 12 years the research organisation Global Water Intelligence and the OECD have conducted a Global Water Tariff Survey. The most recent was completed in 2010. The survey considered the prices charged in 276 cities around the world. It looked at the total cost of water services, including fixed charges for water and wastewater services, volumetric charges for water, volumetric charges for wastewater and total sales tax. The survey’s authors considered both water and wastewater charges as, in many jurisdictions there is just a single charge for services, while in others significant crosssubsidies exist between water and wastewater services. To calculate the effective rate for water the authors looked at the total cost to a household using 15 kilolitres of water per month and divided this total by 15 to get a nominal cost per kilolitre. The survey’s findings are expressed in $US.

Rising water prices primarily reflect the cost of new services.

50 SEPTEMBER 2011 water

In the 12 months since the previous Global Water Tariff Survey was conducted, global water prices increased by 8.5%. This builds on substantial rises during the previous period (2008–09) of more than 9%. These increases appear to be

feature articles


feature article driven by a general move towards a reduced reliance on state subsidies in cities across the world. The biggest increases came in Mexico and Eastern Europe, and most notably Russia. In Mexico City, reforms changed the basis of charging to reflect the income of households. That is, while an inclining block tariff structure still applies to low-, medium- and high-income households, each group pays a different rate according to their means. Under this new arrangement, prices for low-income households increased by 85.9%, while prices for the mediumincome group increased by more than 500%.

Table 1. Current prices and percentage increases of a range of global cities (Global Water Tarriff Survey 2010). City

Current Price ($US)

Per cent increase since last survey

World’s Top 10

Of course this is an extreme, and it cannot be said that Australian water prices are not comparatively high. In fact, viewed on a country-by-country basis, Australia is the third most expensive at $US4.18/kl (combined water and wastewater tariff using the GWI/OECD methodology), behind Denmark ($US7.81/kl) and Germany ($US4.26/kl). Among the list of Top 10 combined city tariffs Sydney was listed at number seven (combined price of $US5.03/kl), between Berlin ($US5.67/kl) and Stuttgart ($US4.93). Table 1 shows a selection of global cities, the current price charged and the percentage increase since the last survey.

Copenhagen

$8.00

2.5%

Aarhus (Denmark)

$7.61

2.9%

Honolulu

$6.06

13.1%

Glasgow

$5.89

0.5%

Gent (Belgium)

$5.79

6.7%

Berlin

$5.67

-1.9%

Sydney

$5.03

12.0%

Stuttgart

$4.93

0%

San Diego

$4.90

13.3%

Frankfurt

$4.89

0%

Other Cities Brisbane

$4.84

15.8%

The steepest tariff increases were in Mexico City, as already reported; Chisinau (Moldovia), which increased tariffs by 81% (but still to only $US0.83/kl); Monterey (Mexico), which raised prices by 65.2% to $US0.59/kl; and Rostov-on-Don (Russia), which increased prices by 62.2% to $US1.02/kl.

Melbourne (City West)

$4.35

14.9%

Vienna

$4.26

5.6%

Auckland

$4.07

1.8%

Paris

$3.91

6.3%

The most expensive cities were Copenhagen, with an effective rate of $US8.00/kl; Aarhus (Denmark) $US7.61/kl; and Honolulu $US6.06/kl. Three cities continue to supply free water and wastewater services: Belfast, Dublin, and Ashgabat (Turkmenistan).

Adelaide

$3.59

13.9%

Perth

$3.57

3.9%

Helsinki

$3.47

23.8%

Gothenburg

$3.32

24.9%

Washington

$2.83

15.5%

Baltimore

$2.72

18.8%

New York

$2.69

13%

Tokyo

$2.24

5.0%

Toronto

$2.08

9%

Cape Town

$1.42

24%

Moscow

$1.08

28%

Investing in Water Security The Summary of the Global Water Tariff Survey notes that “the average increase of 12.1% in Australia is largely down to the need for higher tariffs to pay for costly desalination infrastructure”, although it also notes that Sydney Water claims to have now secured water supplies to 2025. Recent price increases reflect primarily the cost of the provision of new services rather than increases in the cost of existing services. The services are primarily enhanced water security through investments in diversification of supply, in many instances the construction of desalination plants.

‘how dare you rip me off?’. You say ‘thank god I didn’t bang my car, but I’ve got the insurance to make sure I am OK’. This year, even if [I don’t use water] I will be charged $100 to have it, but that is insurance. It is about security, not about the volume of water.”

Observed one CEO interviewed for the AWA/Deloitte State of the Water Sector Survey: “If you insure your car and don’t write [it] off, you don’t ring the insurance company and… say

Photo: Kerry Myers

Even when increased water supply security has not been the driver of price increases (such as in Tasmania, where increased prices reflect the need to overcome a legacy of under-investment) increases cover the cost of service improvement, not the status quo.

Low levels at Warragamba Dam prompted the building of the Sydney Desalination Plant, an investment for which consumers are paying.

Of course, in delivering services it is still incumbent on governments, regulators and, primarily, utilities to make sure that capital expenditure is efficient and appropriate. Speaking recently at the Productivity Commission’s Sydney hearing in March, Jim Cox, CEO of NSW’s economic regulator, the Independent Pricing and Regulatory Tribunal (IPART), said that one of IPART’s goals in regulating water utilities was to ensure that investment in capital works was efficient. He claimed, in respect of the Sydney Desalination Plant, that the Tribunal’s oversight had ensured that the investment was efficient, at least with regard to investment in the plant (although not necessarily the financing arrangements). It would be hoped that capital expenditure has been efficient in all jurisdictions.

water

SEPTEMBER 2011 51


feature article

The 1994 COAG Water Reform Agreement and the National Water Initiative both endorse the notion that full cost recovery should be achieved, and it follows that costs are going to be passed on to consumers. This is legitimate. Regardless of what one thinks about the timing of augmentation, the investment made in providing the level of water security now available needs to be recovered. If it is not, the only alternatives are a reduction in expenditure elsewhere (for example, on maintenance), increased debt, or subsidisation by governments, none of which are desirable.

In a speech to the AWA Victorian Branch Annual Dinner, NWC Commissioner Chloe Munro observed that “the urban water sector is suffering from heightened public anxiety about prices and very little awareness of value. The glass of wine I enjoyed earlier this evening or the cup of coffee I had this morning cost more than I’m paying for a week’s supply of water… even with the price rises that are in train, our water supply and wastewater services represent spectacularly good value.” Nothing can be truer, but if so, more effort appears to be needed to explain to consumers this value proposition, because at the moment, as Ms Munro observed, the message is not being received. It is legitimate to invest in water systems to ensure supply security. It is equally legitimate, indeed essential, to make investments in system maintenance, environmental protection, augmentation, improvements in customer service and like factors, and reasonable that these costs should be passed on to consumers, as long as they are efficient. It is interesting, therefore, to note that a previous iteration of the Global Water Tariffs Survey carried out in 2008 included the following comment: “Berlin and Stuttgart have reduced their tariffs. Whereas utilities in the rest of the world never invest enough to meet the next environmental challenge, German utilities have always maintained a high level of investment and are now in the position of seeing a dividend from capital expenditure to improve operational efficiency”. It could equally be said that Australian utilities have invested in the future, making sure that our capital cities and major regional centres will survive the next drought without having to resort to emergency levels of water restrictions.

Anti-infiltration overflow-relief device

N PR E OD W UC T

The timing, or appropriateness, of investment is possibly a different matter. Faced with drought conditions, governments have been very anxious to invest heavily in desalination, despite such investments sometimes appearing premature. For example, a review of the former NSW Government’s 2006 Metropolitan Water Plan recommended that investment be made in desalination in Sydney when dam water levels fell to 30%, and possibly less, pending further investigations. However, despite adopting this recommendation as part of an adaptive approach to supply augmentation, the former Government committed to construction of a desalination plant when dam levels were at 34.3%. The preferred tenderer was announced when levels were at 51.4% and contracts were signed at 57.2%. Since then, storage levels have never looked close to falling to less than 30% and currently stand at 78.1%. The cost of the Sydney Desalination Plant was $1.9 billion. The former Government’s actions could be considered akin to taking out insurance before you’ve bought the car. The Productivity Commission has been critical of the decision, suggesting that it has imposed costs on consumers that need not have been incurred at this time.

 Eliminates infiltration through conventional ORG  Reduces waste water treatment costs  Minimises entry of pests  Reduces likelihood of untreated discharges

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feature article

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water

SEPTEMBER 2011 53


feature article

The Carbon Pricing Scheme – Opportunity in Disguise? Carbon pricing will inevitably have impacts on the water industry, but it will also present opportunities to show leadership in the field. S Alimanovic, K Simmonds, B Henderson, A Fearnley A decade has passed since the Howard Government’s Australian Greenhouse Office (AGO) published its emissions trading discussion papers and initiated national consultation on the design of a potential carbon pricing scheme. The announcement of the set price, which is planned to commence in July 2012, is causing a few of the big industrial players to anticipate how much of an impact this price will have on their operation, and has polarised politicians and the public on the topic of global reduction efforts. The question for water businesses – and, indeed, for every business – is what the carbon price and future emissions trading scheme (ETS) means for them. How does a business plan for the impacts and position itself to capitalise on opportunities? Are the opportunities significant and worth planning for now? There are many questions that have subtle variations for every water business around Australia. A sensible approach to answering some of these questions is: 1. To look at what this carbon pricing mechanism (Scheme) actually means for each particular business; 2. To understand and assess the real impacts of the Scheme on their operations, including quantifying the magnitude of the impacts identified;

During the fixed price period the carbon price will start at $23/tonne and increase by 2.5% in real terms each year. Liable Entities may purchase permits from the Government at the fixed price, up to the number of their emissions each compliance year (being 1 July to 30 June). Liable Entities are limited to meeting 5% of their liability in the form of Kyotocompliant Australian Carbon Credit Units (ACCUs) created from eligible offset projects under the Carbon Farming Initiative (CFI) during the fixed price period. During the flexible price period, Liable Entities will be able to surrender up to 50% of eligible international units to meet their compliance obligations, in addition to purchasing carbon permits at auction and purchasing Kyoto-compliant ACCUs. A price ceiling and price floor will apply for the first three years of the flexible price period. The ceiling price will be set at $20 above the international carbon price and will rise by 5% in real terms each year. The floor price will start at $15 and rise at 4% in real terms each year. A summary of the tax is presented graphically in Figure 1 (note that the ceiling price is calculated using the current international carbon price, which is approximately $AUD15 /tonne – July 2011 – Thomson Reuters, 2011 Climate and Business Conference, Wellington).

3. To mitigate the potential impacts through improved energy use and more sustainable business practices. While the impacts of the Scheme on business operations are important, there are also real opportunities presented by the introduction of a carbon price. Perhaps a more significant question the water industry should be asking is: “How can we play our part in restructuring the future economy for efficient use of energy, while meeting customer needs and remaining a viable and sustainable business?”.

Summary of the Carbon Pricing Scheme On 10 July 2011 the Government announced its intention to introduce a carbon pricing mechanism to Australia. The Scheme is designed to limit Australia’s emission of greenhouse gases and ensure Australia reaches its unconditional pollution target of 5% below 2000 levels by 2020. This translates to abatement of 160 million tonnes of carbon dioxide equivalent by 2020. In the Australian Government’s Climate Change Plan, Securing a Clean Energy Future, the Government specifies that the imposed carbon price will provide a financial incentive to reduce energy consumption through innovation and efficiency measures. The Scheme will directly apply to the 500 biggest emitters (Liable Entities) and flow through the economy to the end user with increased energy costs. If the Scheme is passed in parliament, initially, a carbon price will be imposed from July 1 2012 for a three-year fixed price period. The Scheme will then transition to a flexible price “cap and trade” ETS on 1 July 2015. Liable Entities will be obliged to surrender permits equivalent to their emissions during the fixed price period and to their “pollution cap” during the flexible price period.

54 SEPTEMBER 2011 water

Figure 1. Graphical representation of the Australian Carbon Pricing Scheme. The Government intends to utilise the funds generated by the proposed Scheme to offset increased costs and support a range of sectors throughout the economy. Major emphasis has been placed on supporting families and low-income earners in order to compensate for any increases in energy bills, or other goods and services, due to the flow-on effect from major emitters. A significant portion of funds generated by the Scheme will be returned to the Liable Entities. There has been some media criticism about the validity of the Scheme and whether it can achieve meaningful emissions reduction in a global context. However, other countries have seen significant emissions reductions and increased renewable energy sector investment due to an ETS. Contrary to some media reports, Australia is not alone in pursuing an ETS, and if the Scheme passes parliament Australia will be the 33rd country to adopt a carbon reduction scheme as of July 2011 (GE, 2011). New Zealand has had an ETS in

feature articles


feature article Table 1. Waste CO2-e emissions for 2009 adapted from NGGI Report, 2011. CO2 –e emissions (Mt)

Greenhouse Gas Source and Sink Categories

CO2

CH4

N 2O

Total

Waste

0.03

13.3

0.4

14.1

Solids waste disposal on land

NA

11.0

NA

11.0

Wastewater handling

NA

2.6

0.4

Waste incineration

0.03

NA

NE

Other waste

NA

NA

NA

place for over 12 months now, and the recently released Report on the New Zealand Emissions Trading Scheme shows that 1340MW of new renewable generating capacity was consented in the past year, with no fossil-fuelled plants being consented. This is a five-fold increase in renewable consenting when compared with the past decade. NZ is also now on target to meet the Kyoto obligations, with net emissions down for the second consecutive year, the first time since 1990. Interestingly, the NZ carbon price is lower than that proposed in Australia.

Potential Impact on the Water Industry Under the current global framework for climate change (the Kyoto Protocol) ratified in 2007, the Australian Government annually reports on greenhouse gas emissions from various sectors, including wastewater handling under the waste sector. The most recent report on Australia’s emissions was compiled by the Department of Climate Change and Energy Efficiency (DCCEE) 2011, and outlined that the total emissions from wastewater handling was 3.0 Mt CO2 –e out of a national total of 364.5 Mt CO2 –e in 2009; this represents less than 1% of total emissions. Wastewater treatment emissions include fugitive emissions in the form of methane, carbon dioxide and nitrous oxide. The numbers imply that the direct fugitive emissions from wastewater treatment are minimal compared to the remaining sectors that are normally accounted for in national emission inventories. Table 1 demonstrates that the emissions that make up the wastewater handling component are mostly in the form of methane production, which typically occurs in anaerobic wastewater treatment processes. The true carbon emissions contribution of the water and wastewater industry as a whole is spread across a range of sectors, including industrial, electrical, waste and transport. The emissions from water and wastewater are, therefore, largely indirect and are difficult to group into a single set of emission data. Figures 2 and 3 present the emissions from various sectors, from the early ’90s to present day and future projections. These emission projections are based on the currently instilled policies and measures in place to reduce climate change impacts, and do not include the effect on emissions likely to result from a price on carbon. It is likely that the carbon price will encourage

emission reductions across the various sectors. Some sectors will be impacted more than others, depending on how ably they can respond and reduce emissions, find energy efficiencies to reduce exposure to increased energy costs, or receive compensation.

To consider the emissions from the water and wastewater industry, it is important to take into account the treatment processes, asset 0.03 management, the space and materials required, NA and customer demand and expectations around water and energy. For this reason, the increased costs that eventuate as a result of the carbon price will most likely present themselves in a number of ways to the water industry, mostly indirectly, and through a number of mediums. 3.0

A significant likely impact on the water industry will be that of increasing power prices arising from the electricity sector’s response to the carbon pricing scheme. This will be an indirect impact, and will drive more efficient treatment process operation in water and wastewater treatment and distribution, and the preference for low-energy consumption treatment alternatives. The main energy-intensive processes in the water and wastewater industry are aeration, desalination, sludge handling, and conveyance and distribution systems, and the carbon price impact will likely support the pursuit of improved and innovative solutions in these areas. On the other hand, some of the larger water businesses may be directly impacted and required to pay a price on their emissions based on whether or not the threshold for fugitive emissions is triggered. These thresholds are yet to be announced, and to add to this there is no direct and simple method for fugitive emissions accounting to assist in understanding cost implications. The larger water authorities in the main metropolitan regions of Australia may need to start planning for risk mitigation and adaptation around the additional costs associated with emissions, and consider including a less energy-intensive approach to future planning in urban environments. While there are a number of risks to businesses as a result of a price on carbon, opportunities exist also. Water corporations with land assets or land management roles can utilise the Commonwealth Government’s proposed Carbon Farming Initiative (CFI). The Government introduced the CFI Bill in March 2011 and it was passed in parliament in early July 2011. Under the scheme, carbon credits may be traded on the international compliance and voluntary markets, as well as the domestic market, depending on the nature of the activity. Kyoto-compliant credits are likely to attract higher returns than non-Kyoto-compliant credits traded on voluntary markets. The CFI also presents an opportunity to major farmers and producers in that any available land could be utilised

Figure 2. Sectoral emissions growth, 1990 to Kyoto period 2008–12 Figure 3. Sectoral emissions growth, 2010 to 2020 (from DDCCE’s (from DDCCE’s Report, Australia’s Emissions Projections 2010). Report, Australia’s Emissions Projections 2010).

water

SEPTEMBER 2011 55


feature article as a carbon sink and ACCUs can be sold to Liable Entities, providing a new source of income for the agriculture industry. The proposal is without precedent in carbon markets around the world and offers opportunities to reduce or offset emissions through carbon sinks, land management changes and technological solutions. The focus of these opportunities is a financial incentive, via carbon credits, to encourage activity that either sequesters or reduces rural carbon emissions. The engineering consulting industry serves water authorities and businesses (among them the 500 Liable Entities) and, as an indirect result, may also be facing further changes in the market and the way they do business. Consulting firms will have the opportunity to provide more work in the energy accounting, climate change risk management and adaptation, and climate change planning areas.

Risk Assessment, Management and Adaptation The nexus between water and energy is worth understanding for every business affected by a carbon price. Every water business will have an ‘embodied’ amount of energy per litre of water (potable and reclaimed) produced. Likewise, for every kWh produced there is typically an embodied amount of water. For example, coal-fired power stations in Victoria’s Latrobe Valley use around 2.1 L of water for every kWh produced (Beyond Zero Emissions – Zero Carbon Australia, Stationary Energy Plan, 2010). Currently, each industry is working towards becoming more efficient within a profitable limit, and the dividend in this is the reduction in the embodied elements in their products. The challenge for the water industry is to meet the needs of a growing population and demand, and use less energy to do it. A carbon price may support the numbers for a successful business case to change wholesale water delivery, treatment and recycling, as well as the adoption of a holistic approach to emissions reduction through improved customer awareness surrounding the water and energy nexus, aiding long-term cost savings. Water utilities must work with their customers to reduce the impact of rising costs for energy and water, while managing customer demand and service expectations. Resources and

Energy Minister, Martin Ferguson, has warned that household electricity prices are set to jump by 30 per cent nationwide in the next three years, even without a carbon price. The water industry must look even closer at the value it provides to its customers. As water and energy are inexorably linked, the water industry has the ability and opportunity to influence a customer’s use of energy. The Australian Bureau of Agricultural and Resource Economics and Sciences estimates energy demand is predicted to grow in Queensland by 72 per cent in two decades, overtaking demand in both Victoria and NSW. Those in the water sector who have been able to negotiate relatively inexpensive electricity prices for decades will face future challenges. It is time for tracking energy efficiency performance in a meaningful way. As the costs of main grid electricity rise, it is worth the investment of time and money to optimise on efficiency and resultant usage – which could reduce these indirect costs of treating water and wastewater. The ability to identify and strategically assess risks is critical to support decision making and management within any organisation. As climate change is projected to reduce water availability in much of Australia’s most heavily populated areas, understanding the extent and economic implications of the climate risk becomes imperative to long-term strategic water planning. The recent long-lasting drought conditions highlighted the water security issues faced by Australia’s capital cities and regional Australia. Most jurisdictions responded by imposing water restrictions and investing heavily in desalination schemes to decrease their reliance on rainfall and surface water resources. While the drought demonstrated significant gaps in Australia’s water planning regime, a benefit was its forced recognition of those gaps and improvements in drought preparedness, as well as water use throughout Australia. Notably, there was a 25% water use decrease in the Australian economy between 2004–2005 and 2008–2009 (ABS 2010).

One impact of carbon pricing is likely be increased investment in the renewable energy sector.

56 SEPTEMBER 2011 water

feature articles


feature article However, reduced water availability is not the only aspect of climate change threatening security of water supply. Many existing risks are expected to become more prevalent with climate change, including risks to infrastructure through changes in climate extreme-event patterns and gradual changes. For instance, sea level rise, flooding, or an increase in high-risk bushfire weather could have serious impacts on the assets of large water utilities such as Melbourne Water or Sydney Water. These risks vary greatly across regions and specific assessments are required to understand the changes in risk profiles, which can underpin future management and ultimately influence water pricing. It should be noted that many water utilities have already undertaken or initiated some form of climate change-adjusted risk assessment, ranging from broad risk-scoping exercises to implementation of detailed adaptation strategies. The long-term pressures of climate change and uncertainty in relation to future Government policy makes the process of risk assessment now even more critical in ensuring long-term water security and customer service reliability.

The strategic and unbiased assessment of risks is critical to support the decision making within any private or public organisation. One of the most significant risks businesses face today is related to the uncertainty of climate change. Assessing and understanding the associated climate risks and opportunities, both holistically and as a result of the carbon price, is critical to long-term strategic water planning for any water organisation. Consideration of the impact of climate change, and extreme events such as floods and bushfires, on catchments and infrastructure should be a key component of this assessment. Further to a climate-adjusted risk assessment, the water industry should aim to improve operational efficiency and reduce energy consumption in the water and wastewater treatment and conveyance areas, to reduce the indirect impacts and resulting additional costs imposed by the Government under the Scheme. There is demand for greater efficiency within our society and among customers across most industries, including the water industry â&#x20AC;&#x201C; this is the definitive moment for the water and wastewater industries and is an opportunity to show leadership.

Conclusion

The Authors

Australia will soon be facing a $23/tonne price on carbon, representing one of the largest economic reforms Australia has seen for decades, and is something into which the water industry must invest strategic and practical resources. The direct implication of the Scheme on industry is difficult to quantify, but it is certain to pose direct and indirect impacts on the broader water industry in Australia. It is clear that water businesses must investigate and plan for the potential risks and opportunities now, to avoid being exposed further down the track.

The authors are all active participants of the Climate Change Working Group of the AWA Sustainability Specialist Network and have collaborated to prepare this article. Sejla Alimanovic is an Environmental Engineer at CH2M HILL Australia Pty Ltd; Kate Simmonds is the ANZ Region Sustainability Coordinator at CH2M HILL Australia Pty Ltd; Brad Henderson is a Project Manager at Wannon Region Water Corporation; and Adam Fearnley is Associate Director â&#x20AC;&#x201C; Water and Infrastructure Services, AECOM.

water

SEPTEMBER 2011 57


wastewater treatment

refereed paper

DEFINING TREATMENT PLANT CAPACITY Equivalent Population is more sensible than Average Dry Weather Flow MP Thomas Abstract The rated capacity of a sewage treatment plant has traditionally been simplified to the Average Dry Weather Flow (ADWF). However, the limitation of this tradition is that ADWF is not a process-limiting factor for the design or operation of any significant unit processes. The mass loads of pollutants (eg, COD, BOD, TSS, TKN, and TP) and/or the Peak Wet Weather Flow (PWWF) are the governing factors for the sizing and operational performance of all treatment processes. The benefit of adopting Equivalent Population (EP) to define capacity is that it incorporates these components of hydraulic and mass loads into a single number. It is recommended that wastewater practitioners take up the challenge and adopt EP, rather than ADWF, for defining both the pollutant loads and plant capacity, and that the rated load and capacity should be based on the design and operational limiting parameter in each case.

Introduction One of the ongoing challenges for the wastewater treatment industry involves coping with the consequences of water conservation. The benefits of water conservation to the water industry as a whole are understood by both the general public and practitioners within the industry. The basic consequence of lower flows into a sewage treatment plant (STP) may appear superficial; however, it has subtle consequences that can lead to confusion when evaluating the pollutant load entering an STP relative to its nominal design capacity. The rated capacity of an STP has traditionally been simplified to the Average Dry Weather Flow (ADWF), or sometimes as the equivalent population (EP) that is connected to the sewer system. The prolonged drought in southeast Queensland during the past decade, and the consequent water conservation measures that were implemented, have

58 SEPTEMBER 2011 water

resulted in significant decreases in the flow per capita entering STPs. During this same period there was widespread population growth in the region. The combined effect of these two factors has resulted in many plants having to operate in excess of their design pollutant mass loads, while the influent hydraulic load remains below the design capacity. This situation can lead to confusion when a treatment plant requires an expansion in capacity despite its influent flow being less than the rated capacity in terms of ADWF. Most operators, managers and designers can readily quote the “capacity” of their STPs in terms of ADWF. However, the limitation of this tradition is that ADWF is not a limiting parameter for the design or operation of any significant unit process, other than diurnal flow balancing tanks. The mass loads of pollutants (eg, COD, BOD, TSS, TKN and TP) and/or the Peak Wet Weather Flow are the governing factors for the sizing and operational performance of all treatment processes. While it would be more precise to define STP capacity in terms of “x kg/d COD; y kg/d TSS; z kg/d TKN”, this is a mouthful and would be cumbersome and tedious.

The benefit of adopting EP to define STP capacity is that it incorporates these components of hydraulic and mass loads into a single number. This concept will be developed and illustrated using a case study of 10 small-to-medium-sized STPs in the Sunshine Coast region. Pollutant mass loads per capita were estimated from an evaluation of influent wastewater monitoring data for Sunshine Coast STPs and were found to be within the expected ranges. The limiting parameter was not the same across all plants, and while flow was limiting at some plants, the organic load (BOD or COD) was more commonly limiting at other plants. Growth rates implied from changes in pollutant loads varied across different STP catchments, as might be expected. However, even within a given catchment, the pollutant loads for all parameters did not increase at consistent parallel rates. Although there are complications and limitations, the simplicity of using a single parameter, namely EP, for defining influent wastewater pollutant loads and STP capacity has merit.

Aerial view of the Suncoast Sewage Treatment Plant.

technical features


wastewater treatment

refereed paper

Methods

Coolum STP 7000

2.

3.

4.

Determine the historical and current actual pollutant mass loads being treated by each STP. Determine the mass load per capita for each pollutant. This needs to be ‘calibrated’ at a defined year when the actual population is known.

Pollutant mass loads were calculated from influent wastewater samples collected once a week. In 2006, these samples were 24-hour composite samples for seven out of the 10 STPs; however, from 2010 onwards all samples were 24-hour composites. All samples were analysed by in-house laboratories using methods that have subsequently attained NATA accreditation. The analysis results for each sample were multiplied by the flow on the day of sampling to calculate the daily pollutant mass load. The daily mass loads were compiled into a data-set for each year and the annual 50-percentile (50%-ile) values were calculated from this data-set.

550

5000

500

4500

450

4000

400

3500

2500

Maroochydore Kawana Noosa

300 250

Slope = 1.9% growth

2000

200

Slope = 7.6% growth

1500

150

Slope = 5.7% growth

100 50

Slope = 2.9% growth

0 2000

2002

Flow

2004 COD

2006

2008

BOD

2010

TSS

0 2014

2012 Total N

Total P

Figure 1. Annual flow and mass loads for Coolum STP, 2000–2010 (50%-ile values). Linear regression lines are shown dashed, and the relative slope was calculated as the gradient divided by the value in 2010. Note that this approach was expected to be more accurate and may give a different result, particularly if the data is not normally distributed, compared to the approach of separately calculating the annual 50%-ile flow and annual 50%-ile concentration and then multiplying these values together.

of Statistics website (ABS, 2007) for each suburb or town in the catchment area of each STP. However, the census population data includes permanent residents only, and this can lead to major errors in areas with significant tourist populations, such as Noosa, Mooloolaba and Caloundra.

For example, for Coolum STP in 2006:

Total numbers of tourists to the Sunshine Coast were between 10 and 13 million visitor nights for 2006, although data was not found to precisely fit the 2006 calendar year (Tourism Research Australia, 2006 & 2008). This corresponds to an average number of tourists on any given day of 31,500. The distribution of these tourists between the different STP catchment was estimated based on data presented by KPMG (2005).

• 50%-ile flow = 5.665 ML/d. • 50%-ile COD = 444 mg/L. • 50%-ile flow x 50%-ile COD = 2515 kg/d. • Whereas, 50%-ile of the COD load calculated daily = 2390 kg/d. Population data from the 2006 Census was obtained from the Australian Bureau

Table 1. Flow and pollutant mass loads for each STP in 2006 (50%ile values), excluding trade waste loads for Nambour and Cooroy. STP

350

Slope = 6.1% growth

3000

500

Compare the actual EP served by each STP with its design capacity to determine the plant’s operational status and identify any need for plant expansion.

600

5500

1000

The calibrated mass load per capita for each pollutant can then be used to translate current pollutant loads into EP.

650

Slope = 3.4% growth

6000

Flow (m3/d); Mass Load (kg/d)

1.

700

6500

Mass Load N & P (kg/d)

The overall objective was to define the actual equivalent population (EP) served by each STP and compare it with the design EP, to quantify whether each plant was overloaded and in need of an expansion in capacity. In order to do this the following procedure was adopted:

Table 2. Current (2009/10) flow and pollutant mass loads for each STP (50%-ile values).

Flow (ML/d)

COD (kg/d)

BOD (kg/d)

TSS (kg/d)

TKN (kg/d)

TP (kg/d)

23.4

10,700

4,000

6,000

1,200

210

Maroochydore

STP

Flow (ML/d)

COD (kg/d)

BOD (kg/d)

TSS (kg/d)

TKN (kg/d)

TP (kg/d)

26

11,000 4,500

6,500

1,200

180

18.5

10,300 3,500

4,300

965

151

16

ND

3,500

3,500

800

135

Kawana

10.5

6,350

3,000

3,200

580

105

Noosa

10

8,000

3,600

4,000

525

100

Coolum

5.5

2,100

800

1,200

200

35

Coolum

5.8

2,700

1,100

1,700

230

38

Suncoast

3.5

1,600

600

730

130

22

Suncoast

3.5

1,650

620

750

140

22

Landsborough

1.5

600

300

260

100

15

Landsborough

2.0

1,100

550

480

125

20

Maleny

0.35

ND

115

115

25

3.9

Maleny

0.37

254

110

120

22.7

3.8

Kenilworth

0.07

34

12.9

15.6

3.6

0.63

Kenilworth

0.07

31.5

12.5

13.4

3.9

0.57

6.4

5,500

2,300

3,000

360

110

0.6

575

248

214

37.3

6.9

Nambour (excluding trade waste)

5.6

3,600

1,250

2,602

290

76

Nambour (including trade waste)

Cooroy (excluding trade waste)

0.57

ND

135

153

30

6.0

Cooroy (including trade waste)

water

SEPTEMBER 2011 59


wastewater treatment Results and Discussion Pollutant mass loads Influent wastewater data from 2000 to 2010 was compiled and mass loads calculated for each sample day as described above. The annual 50th %-ile result for each pollutant was then plotted; for example, the results for Coolum STP are shown in Figure 1. A linear regression curve was also plotted to assist with estimating the ‘smoothed’ growth in mass loads for each parameter. The average loads for 2006 (ie, Census year) and current 2009/10 operating loads were determined from the data and plots, and are summarised in Table 1 and Table 2. The results presented in Figure 1 reveal a number of interesting characteristics. First, all parameters indicate that the Coolum catchment is experiencing

refereed paper

moderate growth rates, whereas some catchments on the Sunshine Coast had low or static growth, and yet others had higher growth rates. However, not all pollutant loads were increasing at consistent parallel rates, and this observation was common to most STP catchments. Organic loads (COD and BOD) and solids loads were increasing at faster rates than nutrient loads (N and P) in this case. This observation leads to questioning the hypothesis that each EP contributes a consistent, repeatable mass load of each pollutant, which is an assumption inherent when adopting “EP” as the defining parameter for STP operating loads and design capacity. However, this is anticipated to be of lesser concern than the disadvantages associated with using ADWF as a defining criterion.

Second, despite the results being averaged over yearly periods, the mass loads do not show steady, consistent growth, which was anticipated for a catchment with practically 100% domestic sewage. This lack of consistency is apparent in Figure 1, whereby the flow and some pollutant parameters display a cyclic increase and decrease from year to year. Although there is an overall trend of steady increases in flows and pollutant loads, which would be consistent with increasing population, there are also some years where flows and loads appear to decrease. A decrease in flow could readily be caused by decreased levels of infiltration during drier years. However, from a practical perspective it is difficult to envisage that there could really be a significant decrease in population that

Table 3. 2006 Population Data for each STP. 2006 Census Permanent Residents

2006 Tourists (Average/day)

Maroochydore

78,114

12,700

90,814

Kawana

65,588

6,000

71,588

Noosa

32,212

10,000

42,212

Coolum

17,115

300

17,415

Suncoast

8,881

1,500

10,381

Landsborough

6,504

0

6,504

Maleny

2,240

0

2,240

STP

Kenilworth

Catchment Total in 2006

254

0

254

Nambour

21,710

1,000

22,710

Cooroy

2,991

0

2,991

235,609

31,500

267,109

Total

Table 4. Flow and pollutant mass loads per capita for each STP in 2006, excluding trade waste loads for Nambour and Cooroy. Flow (L/EP/d)

COD (g/EP/d)

BOD (g/EP/d)

TSS (g/EP/d)

TKN (g/EP/d)

TP (g/EP/d)

Maroochydore

258

118

44

66

13.2

2.3

Kawana

224

ND

49

49

11.2

1.9

Noosa

249

140

66

71

12.8

2.3

Coolum

316

121

46

69

11.5

2.0

Suncoast

337

154

58

70

12.5

2.1

Landsborough

231

92

46

40

15.4

2.3

Maleny

156

ND

51

51

11.2

1.7

Kenilworth

276

134

51

61

14.2

2.5

Nambour (excluding trade waste)

248

159

55

115

12.8

3.3

Cooroy (excluding trade waste)

191

ND

45

51

10.0

2.0

50%-ile

248

134

50

64

12.6

2.2

Mean ± Std Dev

248 ± 54

131 ± 23

51 ± 7

64 ± 21

12.5 ± 1.6

2.25 ± 0.4

Typical values

140-300

115-130

50-60

55-70

11-14

2.0-2.5

STP

60 SEPTEMBER 2011 water

technical features


wastewater treatment

refereed paper

would cause a decrease in pollutant loads. A more likely explanation is that this is an indication of the magnitude of the sampling and analysis errors, which is likely to be related to the challenges associated with collecting a representative sample from a heterogeneous mixture such as raw sewage.

wastewater loads when calculating the results in Table 1. Note that trade waste loads were only deducted for the purposes of calibrating the mass loads per capita, whereas the total influent loads including trade waste were used for determining the operating load (Table 2).

This highlights the importance of collecting raw sewage samples from well-mixed locations in the inlet works. For example, sampling from a vortex grit tank is better for obtaining a representative sample than from a section of channel where there may be some degree of stratification of solids concentrations between the floor and upper water layers in the channel.

The population data determined for each treatment plant catchment is summarised in Table 3.

Finally, it is worth noting that the Sunshine Coast region was not subject to the same water restrictions as most other parts of South-East Queensland until 2009; thus the Coolum catchment shows growth in influent flows that was approximately parallel with the mass load growth. No influent wastewater testing for COD was carried out for Kawana, Cooroy or Maleny STPs during 2006; consequently no data (ND) is indicated for these parameters in Table 1. Since the objective was to determine average pollutant mass loads per person, then it was necessary to deduct any significant industrial trade waste contributions from the influent loads. Only two of the catchments, Nambour and Cooroy, have significant trade waste contributions (>20% of total pollutant load). In these cases, trade waste monitoring data was available to quantify these trade waste loads and they were deducted from the total influent

Population data

Mass loads per capita The results for pollutant mass loads in 2006 (Table 1) and the population data for the same year (Table 3) were used to calibrate the pollutant loads per capita, and the results are shown in Table 4. Generally, the results fell within the expected range for each pollutant, which provided confidence that the presented concept was valid. Several of the results presented in Table 4 were well outside the expected range and require further discussion. Firstly, with regard to flows, only the Cooroy and Maleny catchments showed flow per capita less than 200 L/EP/d. This may reflect entrenched water conservation attitudes in rural hinterland towns, where populations probably historically relied on tank water and coping with water shortages was a normal situation. By comparison, the Suncoast catchment showed higher than usual flows per capita of approximately 340 L/ EP/d. The Suncoast catchment includes a significant tourist population in hotels at Marcoola and a resort at Twin Waters, and relaxed attitudes to water conservation may be reflected in this case. The Suncoast and Coolum catchments both had flows per capita of >300 L/EP/d, and since these

are both low-lying, flat, sandy catchments this likely indicates that there may be permanent infiltration to the sewer networks. The Nambour catchment had high values for COD and TSS loads per capita. The likely cause was that the industrial trade waste contributions were higher than indicated by the trade waste monitoring results. The main trade waste contributors are food industries, with the loads being dominated by COD and TSS. Furthermore the monitoring results showed very high variability. It appears that the trade waste monitoring, while correctly indicating this variability in concentrations, did not accurately capture the true average discharge loads of these parameters. The Nambour catchment also showed high values for the P load per capita. However, this is likely to be an artefact of the influent sample location, which includes recycles from the dewatering of anaerobic digestion of biological nutrient removal sludge, which typically has very high levels of phosphate arising from P release in the anaerobic digesters. The Suncoast catchment also had a high COD load per capita; however, no reason for this could be identified. The Landsborough catchment showed a high per capita load for TKN; however, low per capita loads for COD and TSS were indicated. This was considered unusual, particularly considering that Landsborough STP receives a significant contribution of septic tank wastes, which would normally be expected to have high levels of TSS and COD, with relatively lower levels of TKN. A potential explanation for the unusual Landsborough influent characteristics was that the

Table 5. Estimated EP loading at current 2009/10 operating loads for each STP. STP

Flow derived EP

COD derived EP

BOD derived EP

TSS derived EP

TKN derived EP

TP derived EP

Maroochydore

104,000

84,615

86,538

101,563

96,000

80,000

Kawana

74,000

79,231

67,308

67,188

77,200

67,111

Noosa

40,000

61,538

69,231

62,500

42,000

44,444

Coolum

23,200

20,769

21,154

26,563

18,400

16,889

Suncoast

14,000

12,692

11,923

11,719

11,200

9,778

Landsborough

8,000

8,462

10,577

7,500

10,000

8,889

Maleny

1,480

1,954

2,115

1,875

1,816

1,689

280

242

240

209

312

253

Nambour (including trade waste)

25,600

42,308

44,231

46,875

28,800

48,889

Cooroy (including trade waste)

2,400

4,423

4,769

3,344

2,984

3,067

292,960

316,235

318,087

329,334

288,712

281,009

Kenilworth

Total

water

SEPTEMBER 2011 61


wastewater treatment analysis was done on grab samples collected early in the morning and these grab samples were not representative since the nitrogen concentration typically has a higher peaking factor than other parameters in domestic sewage.

Comparison of design capacity and operating loads The results for the pollutant mass loads in 2009/10 (Table 2) were used to calculate the current operating loads in terms of EP for each STP based on the calibrated mass loads per capita (Table 4). Note that, for this assessment, the adopted COD load was 130 g/EP/d, and the BOD load was adjusted to 52 g/ EP/d to permit a more “typical” COD to BOD ratio to be incorporated. For other parameters, the mean values in Table 4 were used unchanged. The contributing population derived from converting the influent wastewater mass loads to EP is summarised in Table 5. The current best estimate of the total population of the Sunshine Coast region is approximately 300,000, and generally the total EP calculated for each pollutant was within 10% of this value. This provided confidence that the concept being applied and illustrated in this paper was valid. Inspection of the results presented in Table 5 reveals that, at any given STP, the EP value varies when calculated using a different pollutant parameter – ie, at each STP a particular pollutant dominates. Furthermore, the dominant pollutant varies from one STP to another. So this

refereed paper

prompts the question: Which parameter is the process limiting factor? In order to determine the processlimiting factor, one needs to consider how each pollutant load can affect the process capacity of a typical biological nutrient removal (BNR) plant: • Flow: Peak Wet Weather Flow (PWWF) governs the capacity of most process units, whereas Average Dry Weather Flow (ADWF) has no impact on the capacity of any process units except diurnal flow balancing tanks. • Organics (COD and BOD): Solids production in a BNR plant is highly dependent on the influent organic load. Solids production governs the capacity of the bioreactors and clarifiers, as well as the sludge processing stream. Furthermore, the organic load is a major contributor to the capacity requirements of the aeration system. • Solids (TSS): Solids production in a BNR plant is highly dependent on the influent solids load. As per the organic load, solids production governs the capacity of the bioreactors and clarifiers, as well as the sludge processing stream. • Nitrogen (TKN): The nitrogen load is a major contributor to the capacity requirements of the aeration system. Furthermore the nitrogen removal requirements frequently govern the bioreactor sludge age, which subsequently determines the sizing of the bioreactors and clarifiers.

• Phosphorus (P): Biological P removal is a partial contributor to the capacity requirements of the aeration system, and governs the need for an anaerobic zone in the bioreactors, whereas if chemical P removal is practised then it is a partial contributor to solids production in a BNR plant. However, unless a plant requires very low levels of effluent P, then the influent P load is unlikely to be the limiting factor for the capacity of any process units. Consequently, ADWF and phosphorus load should be excluded from the determination of which parameter is the process limiting factor. Therefore, the process-limiting factor is the maximum contributing EP load derived from the sub-set of COD, BOD, TSS and TKN loads. The actual EP defined by the process limiting load has been compared with the design capacity of each STP to determine its operational status (Table 6). While any plant that is operating above its design capacity indicates efficiency gains achieved through optimisation (assuming the plant is not breaching its regulatory licence), it also indicates a situation of increased risk because safety margins within the process headroom are being eroded. The results in Table 5 and Table 6 highlight several interesting observations: • Maroochydore and Suncoast are the only plants where “flow/ADWF” indicates the maximum apparent EP (Table 5).

Table 6: Comparison of design capacity and operating loads for each STP. Design Capacity (EP)

Actual Operating Load (EP)

Operating Load/ Design Capacity

Limiting Parameter

Maroochydore

136,000

101,563

75%

TSS

Kawana

76,000

79,231

104%

COD

Noosa

48,000

69,231

144%

BOD

Coolum

25,000

26,563

106%

TSS

Suncoast

12,000

12,692

106%

COD

Landsborough

10,000

10,577

106%

BOD

Maleny

2,000

2,115

106%

BOD

520

312

60%

TKN

Nambour (including trade waste)

32,000

46,875

146%

TSS

Cooroy (including trade waste)

4,000

4,769

119%

BOD

STP

Kenilworth

62 SEPTEMBER 2011 water

technical features


wastewater treatment

refereed paper

• Suncoast is the only plant operating above its design ADWF; however, eight out of the 10 plants are operating beyond their design capacity (Table 6). • This reinforces that ADWF is generally a poor indicator of operating load. • Nambour is the only plant where phosphorus (P) indicates the maximum apparent EP; however, this needs to be discounted as an artefact of sampling since the influent includes recycles from dewatering of anaerobic digested biological P removal sludge. • Generally, the apparent EP indicated by the P loads was low, which may indicate a trend towards increased use of phosphate-free detergents. • The trade waste loads to Nambour are dominated by organics (COD, BOD) and solids (TSS) and these components govern the operating load. • Similarly, trade waste loads to Cooroy are characterised by high soluble organic loads in combination with low solids loads, which is consistent with the expected waste characteristics from a soft drink factory. The organic load defines the limiting operating load.

Conclusion Wastewater engineering has evolved over the past decades to the extent that more rational scientific methods are displacing traditional empirical rules, such as rules of thumb based on hydraulic residence time. Further developments will likely arise from advances in technology, as well as by us continuing to challenge traditions. It is recommended that wastewater practitioners should adopt equivalent population (EP) rather than ADWF for defining both the pollutant loads and plant capacity, and that the rated load and capacity should be based on the design and operational limiting parameter in each case. A procedure for determining the operating load in terms of EP has been presented and validated in this paper.

The Author

Michael Thomas (email: michael. thomas@unitywater.com) is the Treatment Technology Manager for Unitywater.

He has 20 years’ experience in the wastewater industry, including STP Operations, Process Optimisation, Technical Support to Operations, Operator Training and Mentoring, and Applied Research and Development.

References Australian Bureau of Statistics (ABS, 2007): 2006 Census data from ABS website: http://www. abs.gov.au/websitedbs/D3310114.nsf/home/ Census+data KPMG, 2005: Mooloolaba regional economic profile, report prepared for GHD and DERM for the Mooloolaba Spit futures study master plan, August 2005, sourced from Sunshine Coast Regional Council website, http://sunshinecoast. qld.gov.au/addfiles/documents/projects/msfs_ economic_profile.pdf Tourism Research Australia, 2006: National visitor survey year ended March 2006, sourced from Tourism Queensland website, http://www. tq.com.au/fms/tq_corporate/news_room/ presentations/QTIC%20October%202006%20 -%20Sunshine%20Coast.ppt Tourism Research Australia, 2008: Regional tourism profiles 2007, Queensland, Sunshine Coast region, Belconnen ACT, August 2008, sourced from Sunshine Coast Regional Council website, http://www.sunshinecoast.qld.gov.au/ sitePage.cfm?code=tourism-reports.

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wastewater treatment

Presentedatat presented

refereed paper

BIOGAS PRODUCTION POTENTIAL FROM MEAT-PROCESSING PLANT Results showed good potential for biogas production M Othman, S Woon Abstract

at mesophilic conditions for 95 days. The VS content of the seed sludge was 85.7%. They reported that the maximum COD removal obtained was 78% at OLR of 2.9 kg COD/m3.day and HRT of 13.2 hr. The average biogas recovery at 30˚C was 0.26 m3 CH4/kg COD with an average methane content of 57%. They also reported that AD was severely slowed down at all HRT tested at the highest organic loading of 4.8 kg COD/m3.day (Atuanya and Aigbirior, 2002).

Anaerobic digestion (AD) technologies have been effectively applied worldwide for the treatment of various industrial wastes and wastewaters. However, in Australia, there is limited implementation of AD for the treatment of livestock wastes. This study investigates the feasibility of AD of wastes generated at a large meat processing plant in Melbourne. The quantity and quality of biogas produced at organic loadings of 2.4, 5.4, 9.3 and 14.5 gCOD/gVS and 0.4, 1.0, 1.7 and 2.6 gCOD/gVS for DAF-sludge and Paunch wastes respectively, as well as organics removal, were assessed at mesophilic conditions. The highest cumulative biogas production (CBP) obtained was from the DAF-sludge at 9.3 gCOD/gVS. The highest CBP for Paunch was 0.45 m3 biogas/kgVSadded at a loading of 2.6 gCOD/ gVS. The CH4 content of the biogas produced from DAF-sludge and Paunch samples ranged from 66%–82% and 53–75%, respectively. This study shows that both DAF-sludge and Paunch can be potentially used for biogas production. A cost-benefit analysis is required to complete the feasibility of using AD for waste management at this site.

Introduction Anaerobic digestion (AD) technologies are well established worldwide, treating various types of wastes and wastewaters from different industries. AD has been effectively used for the treatment of wastes generated from abattoirs, poultry, livestock and slaughterhouse (Chávez et al., 2005; Güngör-Demirci and Demirer, 2004; Ince, Ince and Yenigun, 2001; Nielsen and Angelidaki, 2008; Sakar, Yetilmezsoy and Kocak, 2009). In addition to waste treatment and sludge reduction/ stabilisation, AD produces biogas that can be used on site to generate electricity, or sold to the local electric power grid for renewable energy. Meat wastes are a suitable substrate for AD because of their high content of proteins and lipids. Studies conducted by Salminen and Rintala (2002a & 2002b) focused on the AD of poultry wastes.

64 SEPTEMBER 2011 water

Paunch, also known as rumen. The study assessed the effect of hydraulic retention time (HRT) and organic loadings of 4.6, 1.0 and 0.8 kg VS/m3.day using semi-continuous complete stirred tank reactors (CSTRs) of 2 and 3L. There was an increase in total solids (TS) and volatile solids (VS) removal when the TS in the feed increased, 74% removal of TS and VS was obtained at 4.7% TS in the feed, whereas only 62% of TS and 68% of VS were removed when the TS in the substrate was 2.3% (Salminen and Rintala, 2002a). Their work showed that up to 140m3 of methane can be produced at a loading of 0.8 kg VS/m3day and an HRT of 100 days, under experimental conditions tested.

The AD of animal by-products was investigated using batch and semicontinuously fed reactors at 55˚C (Hejnfelt and Angelidaki, 2009). Their work showed that mesophilic digestion was more stable than thermophilic digestion, and higher methane yield was noticed at higher ammonia-N concentrations. The lower yield at thermophilic temperature was due to high ammonia-N concentration. Codigestion of 5% pork by-products mixed with pig manure at 37˚C showed 40% higher methane production compared to digestion of manure alone. In Australia, there is limited implementation of AD for the treatment of livestock wastes. This study investigated biogas production potential of both dissolved DAF sludge and Paunch from a large meat-processing plant in Melbourne.

Methodology Waste and anaerobic seed characteristics Waste samples were collected from a meat-processing plant in Melbourne. The plant employs a dissolved air flotation (DAF) unit. The samples collected were DAF-sludge and Paunch. Characteristics of both samples are shown in Table 1.

But higher loadings and shorter HRTs inhibited and overloaded the process due to the accumulation of volatile fatty acids (VFAs) and long-chain fatty Table 1. Characterisation of DAF-sludge and Paunch. acids (LCFA) Parameter Concentration (Salminen and (mg/L) DAF-sludge Rintala, 2002b). pH 6.1 Atuanya and Total Solids (TS) 91,880 Aigbirior (2002) investigated Volatile Solids (VS) 78,000 the feasibility of Total COD 241,667 AD of poultry 995 Phosphorus (PO43-) wastewater in a continuous flow Total Nitrogen (TN) 2,275 UASB reactor 388 Ammonia (NH3-N) of 3.5L volume

Paunch N/A 76,034 13,104 43,296 N/A 6,100 1,850

technical features


refereed paper

presented Presentedatat

Table 2. Characterisation of the anaerobic seed used in this study. Parameter pH

Table 3. Performances of AD reactors for DAF-sludge and Paunch sample. DAF

Concentration 7.5

Total Solids (TS), mg/L

20,000

Volatile Solids (VS), mg/L

11,100

Total COD, mg/L

22,500

Phosphorus (PO43-), mg/L

1,625

Total Nitrogen (TN), mg/L N

4,300

Ammonia (NH3-N), mg/L

wastewater treatment

610

The mixed anaerobic culture used as seed was obtained from the anaerobic sludge digester located at a large wastewater treatment plant in Melbourne. It was stored at 4°C prior to use. The seed characteristics are shown in Table 2.

Experimental setup

W:S ratio

10:90

20:80

30:70

40:60

CODt removal %

90.84

88.74

95.39

91.04

TS removal %

30.59

31.61

38.36

33.58

Biogas (m / kgVS)

0.44

0.38

0.56

0.33

3

Paunch W:S ratio

10:90

20:80

30:70

40:60

CODt removal %

92.27

85.75

94.78

95.78

TS removal %

26.30

29.28

52.10

54.90

Biogas (m3/ kgVS)

0.22

0.29

0.36

0.45

Batch anaerobic reactors (Grace Davison, US) of 250mL volume each were operated at mesophilic conditions (35°C) for 45 days. The effective volume of the reactors was 100mL. The AD of the DAF-sludge was carried out at different organic loadings of 2.4, 5.4, 9.3 and 14.5 gCOD/gVS obtained by mixing DAF-sludge to seed at a ratio of 10:90, 20:80, 30:70 and 40:60 respectively. The AD of the Paunch waste were 0.4, 1.0, 1.7 and 2.6 gCOD/ gVS, achieved by mixing Paunch to seed at a ratio of 10:90, 20:80, 30:70 and 40:60, respectively. A control and a blank were operated. All the reactors were sealed with natural rubber sleeve stoppers, and maintained in a shaker (INFORS HT, Switzerland) at 35±1°C and 100 rpm. The reactors were monitored by measuring biogas production on a daily basis, the percentage of CH4 in the biogas on a weekly basis. Full characterisation of the effluent was performed at the end of the experiment. The content of methane in the biogas was determined as follows. A known volume of headspace gas (V1) produced in a serum bottle was syringed out and injected into another serum bottle containing 20 g/L KOH solution. This serum bottle was shaken manually for 3–4 mins so that all the CO2 and H2S were absorbed in the

concentrated KOH solution. The volume of the remaining gas (V2), which was 99.9% CH4, in the serum bottle, was determined by water displacement. The ratio of V2/V1 provided the content of CH4 in the biogas (Demirer et al., 2000).

Figure 1. CBP generated for different DAF waste to seed (W:S) ratios.

Figure 2. CBP generated for different Paunch waste to seed (W:S) ratios.

Results and Discussion Cumulative Biogas Production (CBP) Two replicates were used for each waste:seed ratio; shown are the average values for the two replicates. The highest cumulative biogas production (CBP) was obtained for the DAF-sludge at a loading of 9.3 gCOD/gVS. The biogas production of DAF-sludge showed a delayed start from Day 0 to 10. This is the case of a degradation production product of lipid-rich materials, which is a known inhibitor of the methanogenic bacteria (Luostarinen, Luste and Sillanpää, 2009). However, from Day 15 to 25, more biogas was produced. Then from Day 25, biogas production stabilised with an indication that the solubilisation of waste was completed. As shown in Figure 1,

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wastewater treatment

Presentedatat presented

Relationship between TS and COD with biogas production Apart from generating biogas, AD should remove the total solids (TS) of the wastes. A reduction of TS did occur in all of the reactors. TS removal ranged from 34–39% for the DAF-sludge, whereas a relatively higher TS removal of 26–55% was achieved for the Paunch waste.

Serum bottles used as reactors. DAF-sludge:seed ratio of 30:70 showed the highest biogas production with almost 1800mL of biogas being produced over a period of 45 days. The reactors with DAF-sludge:seed ratio of 30:70 and 40:60 showed an increase in biogas production around Day 27. This suggests that a fraction of the organic matter in the DAFsludge was slowly biodegradable, or it may be that the degradation of the easily degradable fraction of organics in the waste sample inhibits the degradation the slowly degradable fraction of organics in the feed (Hernandez and Edyvean, 2008). The CBP produced from Paunch (Figure 2) showed different patterns compared to the CBP from the DAFsludge. The highest CBP for Paunch was 0.45 m3 biogas/kgVSadded at a loading of 2.6 gCOD/gVS. As shown in Figure 2, the Paunch:seed ratio of 40:60 produced the largest volume of CBP (approximately 530mL of biogas) followed by Paunch:seed ratio of 30:70 (425mL of biogas). For all Paunch:seed ratios, the biogas production was slow from Day 3 to Day 5 and then progressed at an increasing rate from Day 7 to Day 30. Biogas production increased slowly from Day 30 onwards except for waste to seed ratios of 40:60 and 30:70, where biogas was still produced at a high rate. Based on this study, it can be seen that DAF-sludge has higher biogas potential as compared to Paunch waste. Using the same ratios, DAF-sludge produced three times more of biogas as compared to Paunch. Assuming that the annual DAF-sludge production at the company is 500ML, it is estimated that the daily biogas production is 53 m3 and daily methane production is 39 m3. If 1m3 CH4 = 10.4kWh (Davidsson et al., 2007), the estimated energy was calculated to be 406 KWh. The percentage of CH4 in the biogas produced from DAF-sludge samples ranged from 66%–82%, whereas the biogas produced from the Paunch samples ranged from 53–75%.

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Results show that a minimum of 85% COD removal was achieved for all the DAF sludge and Paunch sample reactors. This indicates that the organic constituents in the samples were almost completely removed within the 45 days of the experiment.

Conclusion Both DAF-sludge and Paunch wastes have a good potential for gas production. The highest CBP of 0.56 m3 biogas/ kgVSadded was obtained for DAF-sludge at a loading of 9.3 gCOD/gVS. The highest CBP for Paunch was 0.45 m3 biogas/ kgVSadded at a loading of 2.6 gCOD/gVS. The biogas produced from both DAFsludge and Paunch wastes contained 50–60% CH4. A minimum of 85% COD removal was achieved for both DAFsludge and Paunch wastes, which exhibit a high potential for reducing trade wastes level. A cost-benefit analysis is required to complete the feasibility of using AD for waste management at this site. Footnote: This paper won the 2011 award for Best Ozwater Poster.

Acknowledgement The authors express sincere appreciation to SWIFT and Eastern Treatment Plant for providing us with samples to complete this study.

The Authors Dr Maazuza Othman (email: maazuza.othman@rmit. edu.au) is a senior lecturer at the School of Civil, Environmental and Chemical Engineering/Environment Engineering, RMIT University, Victoria. Sabrina Woon (email: sabrina.woon@rmit.edu.au) is a Masters of Engineering student. Her study is focused on the biogas production from meat processing wastes. She graduated with a 1st Class Honours Degree in Chemical Engineering.

References Atuanya EI & Aigbirior M, 2002: Mesophilic Biomethanation and Treatment of Poultry

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WasteWater Using Pilot Scale UASB Reactor, Environmental Monitoring and Assessment, Vol 77, No 2, pp 139–47. Chávez PC, Castillo LR, Dendooven L & Escamilla-Silva EM, 2005: Poultry slaughter wastewater treatment with an up-flow anaerobic sludge blanket (UASB) reactor, Bioresource Technology, Vol 96, No 15, pp 1730–6. Davidsson A, Jansen JC, Appelvist B, Gruvberger C & Hallmer M, 2007: Anaerobic digestion potential of urban organic waste: a case study in Malmö, Waste Management & Research, Vol 25, No 2, pp 162–9. Demirer GN, Duran M, Güven E, Ugurlu Ö, Tezel U & Ergüder TH, 2000: Anaerobic treatability and biogas production potential studies of different agro-industrial wastewaters in Turkey, Biodegradation, Vol 11, No 6, pp 401–5. Güngör-Demirci G & Demirer GN, 2004: Effect of initial COD concentration, nutrient addition, temperature and microbial acclimation on anaerobic treatability of broiler and cattle manure, Bioresource Technology, Vol 93, No 2, pp 109–17. Hejnfelt A & Angelidaki I, 2009: Anaerobic digestion of slaughterhouse by-products, Biomass and Bioenergy, Vol 33, No 8, pp 1046–54. Hernandez JE & Edyvean RGJ, 2008: Inhibition of biogas production and biodegradability by substituted phenolic compounds in anaerobic sludge, Journal of Hazardous Materials, Vol 160, No 1, pp 20–8. Ince O, Ince BK & Yenigun O, 2001: Determination of potential methane production capacity of a granular sludge from a pilot-scale upflow anaerobic sludge blanket reactor using a specific methanogenic activity test, Journal of Chemical Technology & Biotechnology, Vol 76, No 6, pp 573–8. Luostarinen S, Luste S & Sillanpää M, 2009: Increased biogas production at wastewater treatment plants through co-digestion of sewage sludge with grease trap sludge from a meat processing plant, Bioresource Technology, Vol 100, No 1, pp 79–85. Nielsen HB & Angelidaki I, 2008: Strategies for optimizing recovery of the biogas process following ammonia inhibition, Bioresource Technology, Vol 99, No 17, pp 7995–8001. Sakar S, Yetilmezsoy K & Kocak E, 2009: Anaerobic digestion technology in poultry and livestock waste treatment – a literature review, Waste Management Research, Vol 27, No 1, pp 3–18. Salminen EA & Rintala JA, 2002a: Anaerobic digestion of organic solid poultry slaughterhouse waste – a review, Bioresource Technology, Vol 83, No 1, pp 13–26. Salminen EA & Rintala JA, 2002b: Semicontinuous anaerobic digestion of solid poultry slaughterhouse waste: effect of hydraulic retention time and loading, Water Research, Vol 36, No 13, pp 3175–82.

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refereed paper

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presented Presentedatat

ANALYSIS OF BREAKDOWN OF TECHNOLOGY TRANSFER IN CAMBODIA

Positioning ceramic water filters as a fundamental service rather than a luxury product C Browne Clean water is requisite for life. In locations where no centralised water distribution system exists, householdlevel ceramic filtration is relied upon to produce water free of pathogens. This technology can be low-cost and simple to manufacture locally, making it an ideal candidate to deliver clean water in developing countries. Despite this, in the field it experiences disuse over a short period of time. This research asserts that this disuse is a breakdown of technology transfer, and provides a framework for improving usage rates and, in turn, the health of its users.

Outline The Introduction provides the aims, needs and background of the research. The Statement of Hypotheses indicates the three stages of the research. The Contextual Background includes an overview of the foundation theories used in the context of the project, which leads into the three-part Evaluation. The Discussion indicates recommendations to improve the technology transfer of the innovation based on theory, and the Conclusion provides a reflection on the work undertaken and potential areas of further research. Finally, the Acknowledgements pay tribute to those who helped directly in this project.

Introduction Research aims and needs In 2007, Engineers Without Borders Australia (EWBA) began to provide technical assistance to the Resource Development International – Cambodia (RDIC) ceramic filter factory to enable upscaling of ceramic water filter (CWF) production within Cambodia (RDIC 2007). The aim of this research is to identify areas of concern around the supply of this household-level technology as RDIC looks to increase its production.

Successful transfer of knowledge and technology is critical to the success of both RDIC’s business model and any development activity. A field note undertaken by the World Bankadministered Water and Sanitation Program (WSP 2007) observes that filters experience disuse over time, as shown in Figure 1. The users in this study received the CWF at little or no cost through the initial stages of the program. This disuse means that users are not gaining the benefits from using the technology, and are also not encouraging further users to adopt it. 100

PERCENTAGE IN USE AT TIME OF FOLLOW UP (%)

Abstract

y = -2.093x + 97.34 R2 = 0.9578

80 60 40 20 0

0

6

12

18

24

30

36

42

TIME SINCE IMPLEMENTATION (MONTHS)

48

Figure 1. Filter disuse over time, WSP (2007). By investigating the trend of disuse, this paper proposes that this failure can be seen as a breakdown in the transfer process. It considers the model in a diffusion of innovations framework, and builds upon the dynamical approach proposed by Ngai and Fenner (2008). This paper contributes to this work by using the theory to identify suitable leverage points, and provide a novel framework for reducing discontinuance by positioning the CWF in the market as a service rather than a product. As 2011 is the Engineers Australia ‘Year of Humanitarian Engineering’, it is apt to reflect that the knowledge and technology that is often transferred to developing countries for profit or financial gain can also be used as a vehicle for social change and improvement of health conditions in those countries.

Project background In situations where there is no centralised water supply, considerable time is spent collecting water from various sources, such as wells, streams, lakes and bores (Grey, 2006). This is extremely time- and labour-intensive and has an impact on health and wellbeing. The water collected is often not fit for drinking due to high turbidity and bacterial levels. Numerous methods for treating and improving water for drinking exist; however, this study only considers ceramic water filters (CWF) at the household level. CWFs have been used as a targeted approach to improving household drinking water quality in Cambodia since 2001 (WSP 2007). 80% of Cambodians live in rural areas, and only 40% have access to an improved water source (UN, 2007). In 2003, RDIC established a CWF manufacturing facility near the capital, Phnom Penh, and produces CWFs using local materials and labour.

Statement of Hypotheses This paper investigates the following hypotheses: 1.

CWF disuse is not linear That the CWF innovation undergoes disuse similar to that of the discontinuance in transfer theory after the adoption decision, rather than the linear relationship suggested in WSP (2007).

2.

Maintenance can reduce disuse That a maintenance mechanism improving knowledge transfer could be used to reduce discontinuance.

3.

A service model can reduce disuse That transfer could be improved by considering the innovation as a fundamental and continuous service, rather than a discrete product.

By showing that Hypothesis 1 holds in this case study, it can be explored in the context of the identified theories in the following section. This will then allow the exploration of Hypotheses 2 and 3.

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international aid projects Attitudes towards water, sanitation and health

This section outlines the theory used for the research. It should be noted that much of this section is an application of theory to situations in which it has not previously been explicitly applied, such as Transfer, Diffusion and Discontinuance in a development context. Therefore, this is to be considered as a contextual background that extends on traditional background materials.

Water, sanitation and health are three key target areas that will help towards achieving the UN millennium development goals. Approximately two-thirds of Cambodians are without access to improved water sources (WSP, 2007), even though the majority live near major water sources. Less than one-fifth have access to improved sanitation (UN, 2008). The sources of water used in filtration for drinking are summarised in Figure 3.

Ceramic filtration The application of ceramics to water filtration has been documented since the early 1980s, originally by Dr Mazariegos (Lantagne, 2001).

Surface Water Deep Well

As a porous medium, fired clay strains out harmful microorganisms from water (Brown, 2007). This is achieved by mixing organic matter of suitable grain size, such as used coffee grounds, with the ceramic when it is in the plastic state. The organic matter burns out during firing, and allows flow rates of 1–3L per hour (WSP, 2007). RDIC manufactures this in a filter kit that costs between US$8–$10 (Hagan et al., 2009), and is shown in Figure 2.

Shallow Well Rainwater

The filtration occurs as a function of the pore size in the ceramic. The larger the pore size, the larger the microorganism that can pass through it. Escherichia coli is the primary bacterium for removal by filtration, as it is directly linked to the occurrence of diarrhoeal disease when ingested (Foppen et al., 2007; Brown, 2007). Ceramic filtration can filter above 99% of E. coli (Flynn, 2005; WSP, 2007). However, ceramic filters cannot filter out viruses or treat groundwater that is contaminated with arsenic (WSP, 2007). As such, a relatively safe water supply is required for ceramic filtration. When compared to non-filter methods, CWFs have been shown to reduce diarrhoeal instances by half (Brown, 2007), diarrhoeal illness being the number one cause of death and disease in children (WSP, 2007).

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0 1

101

86 83

The CWF in Cambodia has reached a level on the threshold between technology acceptance and technology application, depending on the region and individual user. It is at this level that continued evaluation of the technology is required to ensure that it remains active practice, and reach the aforementioned “reinvention”. In a Western situation, the result of a failure at the technology application level would result in the customer adopting a competitor’s product. In a situation where there is little alternative, the likely scenario is for the user to consume dirty water, which places the user at unnecessary risk. It is this risk that amplifies the need for ongoing evaluation of the transfer process.

Diffusion and discontinuance

3 Number of Respondents =180) (Wet Dry Season Season

127

Figure 3. Water sources used for filtration (derived from data in Brown, 2007).

Photo: Judy hagan, 2009

Figure 2a. A ceramic filter unit. Figure 2b. Schematic of a ceramic filter in use (WSP 2007).

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This lack of access to improved water and sanitation in Cambodia has serious health effects on the population. In a survey undertaken in Brown (2007) on water-use behaviour, the majority of respondents had not received health education. Approximately only half of respondents report that they always wash their hands with soap at critical times, and approximately half of respondents report using their hands when drinking from the filter. This highlights that the technology is one part of a multifaceted problem. The CWF is one of many steps for Cambodia on the development path.

Technology and knowledge transfer As with development, transfer of knowledge and technology is complex, and requires a truly multidisciplinary approach (Seely, 2003). Transfer of small-scale, grassroots technology is not a widely explored topic; much of the transfer-to-developing-countries literature focuses on setting up offshore manufacturing for competitive advantage, such as cheaper labour. There are three levels of transfer required for what is labelled a “successful” transfer: technology development; technology acceptance; and, finally, technology application. Rogers (2003) describes the end point of transfer as a “reinvention”, where the receiver adapts and customises the innovation to their given situation.

When an innovation is exposed to a market, the diffusion process can be mapped in an S-shaped curve. Different products will map to the classic S-shaped curve on different scales. Different categories of receivers in the transfer process play a distinct role in the diffusion of an innovation. Rogers’ (2003) widely accepted definition is the social breakdown of the adopters of innovations, shown in Figure 4. Innovators and early adopters play a crucial role in the diffusion process, as they are often considered as trendsetters. N PERCENTAGE ADOPTIONS

Contextual Background

Presentedatat presented

MAXIMUM ADOPTIONS LAGGARDS (16%)

POINT OF INFLECTION

LATE MAJORITY (34%)

EARLY MAJORITY (34%) INNOVATORS

0

(2.5%)

EARLY ADOPTERS (13.5%)

TIME

Figure 4. S-shaped growth as described in Rogers (2003). Discontinuance is the decision to reject an innovation after initially adopting it. Leuthold (1967) argues that the discontinuance by different actors of an innovation is just as important as adoption. Discontinuance requires intensive data collection and is much harder to measure than adoption, as there are no readily available analogous statistical measures, such as sales, to collect data easily. As a result, discontinuance in many situations is hard to quantify, even though understanding the reasons for the discontinuance can be a valuable resource for product development.

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presented Presentedatat

Evaluation of Hypotheses

Table 1. Surveyed Reasons for Disuse (WSP, 2007) Reason

Hypothesis 1: CWF disuse is not linear

Percentage

Broken (element, tap or container)

65

Past its 2-year lifespan

5

Cannot meet water demand

5

Water is ‘already clean’

3

Gave filter to another household

3

Other reasons

19

Reasons for discontinuance A major finding from the WSP field note (2007) is that filter disuse rate is approximately 2% per month, as shown graphically in Figure 1. Disuse is categorised into six reasons, as shown in Table 1. In the survey, no data was collected accounting for the type of CWF breakage, so it is unknown whether there is a weakness in the design of the CWF or associated plastics. Further, it is unknown how the break took place – whether it was due to a defect or misadventure. Inspection after breakage was difficult, as the CWF was often discarded after disuse: it is unknown whether breakage was the actual reason (WSP, 2007). Understanding the reason for breakage could help target a design approach to address the breakage problem. A new design was considered outside the scope of this research, but as it is the prominent reason for discontinuance, it provides insight into how the transfer process could be improved.

However, in a dynamic, real–life situation the users do not exist in isolation. When considering discontinuance, the number of current users is of interest, as distinct from the percentage of filters in use. This is best shown using Eysenbach’s (2005) model: the reverse S-shaped growth described in the previous section. Using the data from Brown (2007), the graph in Figure 5 was plotted. PHASE I CURIOSITY

100

PHASE II ATTRITION

NON-ADOPTERS

60

It should be noted that this data is not an ideal set for discontinuance, as it is based on a retrospective time since filter manufacture rather than a continual survey of filters in use; however, it does present an alternative trend. Any further survey should consider this data need. Although it has been argued that Hypothesis 1 holds, more information about the data could elicit a deeper understanding of behaviour. The following information could provide greater insight if a follow-up survey were to be undertaken: 1.

Seasonal production availability (due to extended drying times in the wet season or inability to produce replacements) may influence the choice to discontinue.

2.

Seasonal adoption and discontinuance may vary due to the shift in water sources and qualities shown in Figure 3.

3.

The data considers CWFs in use and not the number of replacement filter elements. Given that the recommended

40 20 0

HARDCORE USERS 0

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TIME SINCE FILTER OR REPLACEMENT FILTER PURCHASE (MONTHS)

Figure 5. Discontinuance expressed in terms of current users (from data in Brown, 2007).

MAINTENANCE MECHANISM

POTENTIAL ADOPTERS

CURRENT ADOPTERS

ADOPTION RATE adoption from advertising

DISCONTINUED POPULATION

DROP-OFF RATE

adoption from word of mouth

drop off fraction

word of mouth fraction

advertising fraction

Application of a dynamical approach 100

PERCENTAGE OF POPULATION

One final note of background is the work by Ngai and Fenner (2008). System dynamics is a business and management tool used to break down a complicated system with multiple inputs and feedback loops. Ngai and Fenner have applied this theory generally to the use of ceramic filtration and propose it as a simple method of understanding the system. This behaviour is shown in Figure 6b and compared to the data from this case study. When this model is simulated, current adopters can be measured against potential adopters and the discontinued population.

PHASE III STABLE USE

80 CURRENT USERS (%)

Eysenbach (2005) uses the “law of attrition” to describe the discontinuance phenomena. It horizontally mirrors the S-shaped growth shown in Figure 3, until such a time where only “hardcore” users are left. Increasing the hardcore user group is key to reducing disuse. If reasons for attrition can be measured or determined, it can provide feedback for improving the adoption process.

As shown in Figure 1, disuse over time is apparent. Figure 1, however, is somewhat misleading in Brown (2007) and WSP (2007). The graph shows that the oddsratio for a filter being in use reduces by 2% per month from an initial intervention.

By applying Eysenbach’s understanding, a further observation arises for discussion. For there to be a sufficient “curiosity” phase, a portion of the initial current users must be nonadopters. That is, these users never had the intention to adopt. This may be due to receiving the CWF for little or no investment under the WSP (2007). These users should be considered as a separate group. This observation is rarely considered in modern diffusion theory, and provides an opportunity for further research.

80

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TIME

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Figure 6a (top). Ngai and Fenner’s (2007) model with the addition of a ‘Maintenance Mechanism’ in red to reinforce usage behaviour with current adopters. Figure 6b (bottom). The long-term effectiveness of improving the disuse rate from 2% per month to 1% per month.

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international aid projects life-span is 24 months, it can be assumed that users after 24 months have replaced their filter elements, although it is unknown. 4.

The data does not account for purchase prices. It may be that the discontinuing users received the filter for a small price, although this is unknown.

This understanding shows that it is reasonable to consider Hypothesis 1 as a likely assertion. Hence, Hypotheses 2 and 3 can be considered in the framework of diffusion theory.

Hypothesis 2: Maintenance can reduce disuse As described in Ngai and Fenner (2008), adoption of ceramic filters can be shown in a system dynamics framework. This model is based on a classical logistic growth model which is explained in great detail in Sterman (2000). However, to use Ngai and Fenner’s model in this case study, the adopters at each stage (potential, current and discontinued) should be considered as three categories: 1.

Intervention Adopters These are the non-adopters who never chose to use the innovation described in Figure 5, but were given the CWF through the intervention at little or no cost;

2.

Organisational Adopters Part of the RDIC strategy is to provide the innovation to schools and government departments. These adopters expose the innovation to a wide audience as described in WSP (2007).

3.

Consumer Adopters These adopters are considered to exhibit typical adoption behaviour. These have been combined in Figure 6a to simplify the figure. A further modification has been made to Ngai and Fenner’s model, in that there exists initial adoptions at time 0 due to the rapid deployment of the intervention. Typical diffusion would have percentage adoption at t=0 as 0%, whereas this has been estimated to be 20%.

It is unknown what the maintenance mechanism in Figure 6a would look like. The term “maintenance” refers to a maintaining of current adopter population, rather than a physical maintenance program on the filters, although it is likely that the former could be achieved through the latter. As shown in Figure 6b, if this maintenance mechanism could reduce the drop-off rate to 1% per month, approximately 15% more users would be using the innovation after the first year in

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Presentedatat presented

the 10-year simulation. Not only does this represent a significant improvement, it also represents an opportunity for RDIC to provide more replacement filter units – a 63% increase – given the recommended life-span of the filter unit is 24 months, as shown in Table 2. By developing the system dynamics framework of Ngai and Fenner, it has been shown that an opportunity exists to maintain the current users. Reducing the drop-off rate also offers significant opportunity for the producers of the filter to sell a greater number of replacement filters, and further opportunity to encourage continued use.

Hypothesis 3: A service model can reduce disuse When a user chooses to discontinue using an innovation, there are two primary reasons for this behaviour: the user is either disenchanted with the innovation and reverts to prior practice, or the user chooses to replace the innovation with a more appropriate technology. For the users of the CWF, the reasons provided in Table 1 tend towards disenchantment, since there is no more appropriate technology available. Users tend to revert to boiling water, or using no filtration whatsoever. Hence, it is in the best interests of all parties that users do not discontinue using the CWF.

refereed paper

be provided on a month-to-month basis for a small fee. In this section, the hypotheses were evaluated. By exploring these hypotheses, discussion around the form and shape of any framework for upscaling can be undertaken.

Discussion In the Contextual Background, reference was made to the levels of technology transfer: technology development, technology acceptance, and technology application. Considering this, and the concepts from diffusion theory outlined in the previous section, recommendations for practical methods to reduce discontinuance can be made. These recommendations are not exclusive or ranked, and could be adopted in a flexible manner.

Level I: Technology Development Aspects 1.

Filters that are ready for use out of the box Colloidal silver is applied to the filter at the factory as a disinfectant. This application induces silver leaching, which creates a metallic taste. To counter this, instructions require the user to fill the filter twice before usage, which is approximately 10 hours of use. This places an unnecessary burden on the user, and failure to follow the instruction leaves the user dissatisfied. By shifting the burden of this instruction to the manufacturer, the user will be less likely to discontinue using the CWF.

2.

Pre-made screen to strain dirty water integrated into the design To reduce the amount of environmental debris, it is suggested that a screen is incorporated into the design. This is shown in Figure 7.

A further finding of the WSP survey (2007) is that one-quarter of participants know how to purchase parts for the filter. This provides an opportunity and incentive for RDIC to improve the distribution of the CWF. The approach undertaken by RDIC to distribute the innovation is as a discrete product sold in units, rather than as a continuous service. I assert that the transfer process could be improved if the approach to distributing the filters was reversed. By replacing the filter component on a regular basis for a small maintenance fee, usage of the CWF innovation is reinforced. This model is being used in a similar fashion in another industry in Cambodia: mobile phone technology. There are generally two methods of paying for a mobile phone: upfront, with a month to-month service fee, or, on a contract, with low upfront cost, on an increasedcost fixed-month contract. Sok (2005) observes that [urban] Cambodians prefer the first option: owning the technology, and paying a month-to-month service fee. I propose that usage of the CWF would be improved if it was approached in a similar manner. The CWF could be largely paid for upfront, and a replacement filter could

Water poured through straining screen

Testing fill line

Low-flow rate tolerance Expected level after 1 hour High-flow tolerance

Figure 7. Visualisation of location of the straining screen and potential schema for the location of fill rates and indicators.

technical features


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3.

4.

Defined flow rate indication The manufacturer instructs that cleaning should take place when the flow rate becomes ‘”slow”. Indicators on the side of the ceramic filter could help the user establish this objectively. Product differentiation The ceramic filter element has undergone various iterations in the manufacturing process, which has resulted in various filtration properties. By making the filter models clearly identifiable, the user will be better able to decide whether a replacement is warranted. This could be done through coloured markers or similar.

Level II: Technology Acceptance Aspects At Levels II and III, recommendations may be best fulfilled by a new service focused on ensuring that filters in use are fit for purpose. This shifts the responsibility of maintenance from the user to this service provider. 1.

2.

3.

More complete instructions provided at the point of sale, including a logbook A logbook-style record for the filter could help users identify when a new or replacement filter element is required. Training and demonstration sessions, including certification Training and demonstration of how filters are used and cleaned can help spread awareness of how to use the device, and help reduce disuse. On-site installation service A trained technician can help the householder identify the best location for the filter to avoid contamination, such as from animals licking the faucet. This also provides the opportunity for the householder to ask questions.

Level III: Technology Application Aspects 1.

2.

3.

Authorised maintenance An authorised maintenance program could allow local experts to monitor the status of the ceramic filter and its use. This can help identify potential problems and encourage continued use. Regular certification that the filter is fit for use As part of authorised maintenance, a certification program could ensure that filters are “fit for use”. A trade-in scheme to incentivise replacement Users should be able to access a trade-in scheme to reduce the cost

international aid projects

presented Presentedatat

USER WSP PURCHASE

VENDOR

vendor ensures user understanding

INSTRUCTION

TRAINING/ INSTALLATION

USE

exchange

FILTER REPLACEMENT

CFs are regularly returned to factory for restoration restored CFs returned

FACTORY REFIRING AND TESTING

cleans CF off site keeps clean CFs for redistribution CLEANING AND SERVICING

Current practice Current stakeholders

TECHNICIAN

Figure 8. Mechanism to reduce discontinuance by providing the CWF as a behaviour-reinforcing service. of capital investment and encourage continued use.

Confluence of Transfer Aspects As more ceramic filters are made for the market, RDIC loses control of the innovation. This becomes a problem as the innovation moves into disuse: disused and broken filters are lost to the system. In any effort to upscale, the innovation should remain the property of the manufacturer and the manufacturer should have a fundamental interest in ensuring that the innovation is working wherever it is installed. The CWFs should be regarded as a continuous service, rather than a discrete product. A scheme whereby the recommendations provided are included to ensure maximum usage could be as described in Figure 8. No detailed costings have been undertaken for the elements, but any scheme developed further should be comparable to current costs. It is also anticipated that a higher usage rate will ensure that economies of scale will be able to be reached.

Conclusion This paper proposed to evaluate three hypotheses. Hypothesis 1 evaluated whether the data from the WSP (2007) survey could be considered in diffusion theory. It established that this assertion held, and also asserts that a new group of users exists in the diffusion of innovations, coined intervention users, based on discontinuance. It was shown that these users appear to be a cross-section of the entire population, including approximately 15% of non-adopters. 35% of intervention adopters appear to be “hardcore” users, which is an extremely positive indication. The effect of a mechanism to reduce discontinuance was evaluated using systems dynamics in Hypothesis 2.

This evaluation showed that significant improvements could be made to the levels of current adopters by employing a mechanism to reinforce usage. Hypothesis 3 was explored and suggestions were put forward for a CWF service model. This hypothesis was unable to be evaluated against existing innovations, but evidence suggests that Cambodians currently adopt innovations such as mobile phones in this way. By reducing discontinuance and reinforcing usage through a service model, the health benefits of the CWF will have a greater reach within the societal system.

Further Research As the participatory development theory suggests, a consultative approach is required to determine whether the service model could be applied to the situation. Although the preliminary research in this thesis shows that Hypothesis 3 has potential, it remains to be proven, and could be the topic of a higher-level dissertation. In addition, further research opportunities exist in the areas of: • Improving filter design for portability and robustness; • Improving the strength of the ceramic filters; • Applying silver colloid before the firing process; • Improving flow rates by roughening the surface finish (sanding to expose voids); • On-the-spot water testing technology; • Reusing material from broken filters as a grog. Footnote: This paper won the National Undergraduate Water Prize at Ozwater’11.

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international aid projects

Presentedatat presented

Acknowledgements

References

The author wishes to thank Jeremy Smith from the ANU for supervising the final-year Engineering thesis on which this paper is based. The thesis also details experimental results for the benefits of refiring ceramics clogged with organic matter, which can be obtained from the author. I would also like to thank Engineers Without Borders Australia for offering research in this important and often-overlooked area and for putting me in touch with such fabulous field volunteers. Finally, I extend my gratitude to Dr Tony Flynn for sharing a slither of his extensive understanding of ceramics with me.

Brown JM, 2007: Effectiveness of Ceramic

The Author Christopher Browne (email: Chris.browne@anu. edu.au) is a PhD student in Systems Engineering at the Research School of Engineering, Australian National University, Canberra, ACT, and is a member of Engineers Without Borders, ACT Chapter.

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Filtration for Drinking Water Treatment in Cambodia. PhD Thesis. University of North Carolina. Eysenbach G, 2005: The law of attrition. In Journal of Medical Internet Research. Internet Healthcare Coalition. Vol 7. Flynn T, 2005: New Filter Promises Clean Water for Millions. Promotional Material. Department of Engineering, ANU, Australia. Foppen JW, M van Herwerden & Schijven, J, 2007: Measuring and modelling straining of Escherichia coli in saturated porous media. In Journal of Contaminant Hydrology, Netherlands, Vol 93, pp 236–54. Grey V, 2006: Community Water Supply in East Timor, Undergraduate Thesis, UWA. Hagan JM, Harley N, Ponting D, Sampson

refereed paper

Leuthold FO, 1967: Discontinuance of Improved Farm Innovations by Wisconsin Farm Operators. PhD Thesis. University of Wisconsin-Madison. Ngai T & Fenner R, 2008: Characterizing the dissemination process of household water treatment systems in less developed countries. Water, Engineering and Development Centre, Loughborough University. Rogers EM, 2003: Diffusion of Innovations. 5th ed. New York: Free Press. Seely BE, 2003: Historical patterns in the scholarship of technology transfer. In Comparative Technology Transfer and Society. Vol 1, pp7–48. Sterman J, 2000: Business Dynamics: Systems Thinking and Modeling for a Complex World. Irwin/McGraw-Hill, Homewood. Sok C, 2005: Factors Affecting Consumer

M, Smith K & Soam V, 2009: Resource

Perceived Value and Purchase Intention

Development International – Cambodia

of Mobile Phone in Cambodia and Taiwan.

Ceramic Water Filter Handbook.

Masters Thesis.

Lantagne D, 2001: Investigation of the potters

WSP, 2007: Use of Ceramic Water Filters

for peace colloidal silver impregnated ceramic

in Cambodia. World Bank Water & Sanitation

filter. Report 2: Field investigations.

Program.

technical features


small systems

ThE CoMMunITy WATER PlAnnER FIEld GuIdE A package to assist Indigenous communities R Grey-Gardner, R Elvin, P Taylor, M Akeroyd Abstract The Community Water Planner Field Guide is a package to assist people working in and for Australian Indigenous communities to develop a local water management plan. The principles within the Field Guide are consistent with the Australian Drinking Water Guidelines and apply the risk management approach to water supplies outlined in the Guidelines’ Framework for the Management of Drinking Water Quality. Australian Indigenous communities are generally remote, have diverse populations and have poor access to services. The Field Guide endorses a shared management approach, whereby residents can manage everyday hazards and risks and are able to access support when required. It was extensively tested during development using an iterative case study approach. The development process highlighted the need to integrate capacity building in the management planning process at all scales. The integration of the package into water management programs throughout Indigenous communities in Australia is now underway. This paper highlights the principles underpinning the package, lessons from the development of the package, and challenges encountered during the adoption process. Keywords: Australian Indigenous water management; remote and rural water management; water risk communication; water planning tools.

Introduction In Australia, there has been substantial work in previous years to develop appropriate processes and linkages between water service providers and managers of small water supplies, in order to improve management of rural and remote water supplies. Worldwide, it is acknowledged that small water supplies comprise the greatest opportunity to reduce health-related disease (WHO 2010) and improve livelihood outcomes (Nichol, 2000). The key to change is to create an enabling environment for shared responsibility between local water

managers and service providers that is supported by policy and practice. The Community Water Planner Field Guide is a package that can assist people living in and working with Indigenous communities to develop a drinking water management plan (Australian Government 2009). The product is the initiative of the National Water Commission and was developed by the Centre for Appropriate Technology (CAT) for Water Quality Research Australia (WQRA). The package comprises largely paper-based graphic materials that are designed for use by a specialist facilitator to assist remote Indigenous communities to develop a plan of action that optimises local selfmanagement. The process involves: • Engaging remote communities in mapping and understanding their existing water supply system; • Identifying water supply risks that can be managed locally; • Identifying potential need for upgrades or enhancement to their existing supply; • Developing a recurrent action plan for proactive management of their supplies. Many of the materials are designed to be used as an ongoing information resource in the community to support regular system checking and maintenance activities, and provide contacts for specialist support in case of elevated hazards. The package is accompanied by ‘train-the-trainer’ course materials, incorporating an emphasis on skills transfer to communities that is embedded in the broader livelihood and community development aspirations. The package was launched in 2009 and has now been distributed to core health agencies and water service providers to integrate into small community water programs. Indigenous communities have received substantial investment over the last 30 years, primarily in infrastructure (HREOC 2001; Willis et al., 2009). The greatest opportunity to capitalise on this investment is to improve reliability and

The Community Water Planner Field Guide instruction book. security through enhanced water supply management. Providing reliable and safe water supplies in remote Indigenous communities now requires a focus in building the capacity of water managers at the local, state and national level to build pathways to recognise and respond quickly to water supply problems. It is acknowledged that the riskbased framework for the Management of Drinking Water Quality inherent in the Australian Drinking Water Guidelines (ADWG) (NHMRC 2004) has dramatically improved water management systems and processes throughout the major utilities and large water supplies in Australia. In effect, the Field Guide is a tool to bring this risk management approach in a practical way to the regional and remote Indigenous communities. This requires strategic and persistent campaigning at all levels to focus attention on ‘what people do’ rather than hardware.

Background to Indigenous Communities in Australia Indigenous communities have particular challenges associated with water supply management (FRDC 1994; HREOC 2001; AHRC 2009). There are numerous Indigenous cultures that represent

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small systems considerable diversity coupled with differing economic, social and ecological systems (Davies et al., 2008; Taylor et al., 2007). The Australian outback is characterised by a set of features including climate variability, scarce resources, sparse population, remoteness and cultural differences that together function in unique ways (Stafford-Smith, 2008). The majority of Indigenous communities experience economic and social disadvantage, as well as high mortality rates (SCRGSP 2009).

These programs are externally funded and generally provide professional services through a water utility or contractor. There is a range of service provision arrangements for the 1000 or so smaller communities that have a population of less than 100 (see Table 1). Since it is largely unaffordable to extend the same model to the smaller communities, many of these have no formalised management at all. These small settlements are generally known as outstations or homelands. Outstations usually consist of a family group living on traditional land, pursuing a range of livelihood and enterprise activities. The occupation of the outstation is usually intermittent, since many Aboriginal people relate residency to a region rather than a specific settlement and intra-regional mobility is high (Warchiver et al., 2000).

The specific challenges for water supply and management can include: • Poor-quality source water; • Low capacity in remote areas to maintain water supplies; • Poor market potential; • High rainfall variability; • A history of water management with a focus on technology and infrastructure;

Knowledge of water supplies for people living in small communities is generally gained informally – that is, residents learn about the water supply operation and maintenance from personal contact, such as working on cattle stations or from a community officer. Consequently, outstation residents are usually knowledgeable about operational procedures; however, broader water management activities, including the importance of regular surveillance, identification of the hazards and risks, or asset management are usually poorly understood (Grey-Gardner, 2008, Beard, 2009).

• Sparse, patchy and mobile populations. In addition, compared to the wider community, Indigenous people experience poor health and widespread social issues that contribute to inadequate local water supply management. Initiatives that seek to provide improved service delivery for water management are affected by cross-sectoral accountabilities, and fluctuating funding cycles and governance patterns (Stafford-Smith and Cribb, 2009). Additional challenges for water management in this context include English as a second or third language, and low levels of literacy and numeracy for remote Aboriginal people (Kral, 2010).

The need to improve local water management capacities for outstation residents is crucial since they are best positioned to identify hazards and respond quickly. A systemic weakness in the water sector and government coordination has overlooked active involvement by residents in managing the hazards and risks of their own water supply.

Within this context, a service provision model for larger communities, generally with a population that is usually greater than 100 people, has been successful in providing water that is reliable and complies with the Australian Drinking Water Guidelines.

Table 1. Community Housing and Infrastructure Needs Survey – Total Number of Discrete Aboriginal Communities per State/Territory in 2006 (ABS 2007). Communities with a population of: State or Territory New South Wales Queensland South Australia Western Australia Northern Territory Australia (total, including Victoria, ACT and Tasmania)

Less than 50 18 85 63 189 510 865

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50–99

100–199

200–499

500–999

16 3 12 41 50

20 5 9 27 29

3 14 7 13 34

0 6 0 1 12

1,000 or more 0 11 0 0 6

123

92

71

19

17

Total 57 124 91 271 641 1187

The Package The Field Guide was developed over a period of 18 months with guidance from a steering committee and practical and technical contributions from a working group, both of which comprised water industry and health specialists. Four trial sites were established to test and modify the Field Guide package resources. The sites were selected based on criteria that included: voluntary participation in the project, a population between 20 and 200 people, and a mix of different water supplies including surface and groundwater sources and locations in both tropical and arid zones. The trial sites refined the process required to convey messages appropriately, as well as the educative requirements of Indigenous people to maintain their water supply systems. The methodology was designed to capture the following groups in the testing process: • Residents who have an interest in or responsibility for the water supply; • Visitors and people external to the resident community (transient populations); • Different social groups within the community, such as women, men, elders and youth. The broad participation of residents was integral to project design, so that in times of shock the resources in the package would be appropriate to whoever would be present. The package consists of posters, activity sheets and an instruction booklet that are packaged in a robust cylinder. Full details of the package are outlined in the final report (Grey-Gardner, 2009).

different Perspectives and Information needs The package had to be applicable to communities all over Australia and be relevant to a significant diversity of Indigenous circumstances across large geographical areas and environmental and climatic conditions. To be applicable to all these different areas, the product is generic. The format is largely pictorial, with limited technical references, which is suitable for Indigenous people. The key topics covered in the package are: • Water quality parameters; • Water quantity and use; • Basic infrastructure requirements; • Emphasis on low-technology water supply systems;

technical features


small systems • Emergency response activities; • Surveillance activities; • Monitoring, with strong emphasis on preventive measures.

1.

A facilitator must select components of the package to suit local needs and jurisdictional requirements. It is the facilitator’s role to identify the management needs of the water supply and the level of understanding of the community and residents to adapt the process and use the resources to fit local needs.

Implementation and Adoption The package has been distributed to key organisations that are responsible for small community water supplies across Australia, such as State Government health and water departments or service providers. There are broad-ranging benefits from using the package for both the water service providers and the Indigenous communities, including clarity of:

2.

• Site-specific water management procedures; • A consistent ‘language’ and understanding of components, hazards and risks of each water system; • Service requirements and support mechanisms; • Shared service and operation requirements; • Asset management and recurrent cost requirements. The implementation of the Field Guide is progressing; however, the key barrier to adoption in the small organisations in remote areas appears to be the general lack of knowledge and understanding of the correct implementation process for water management programs. Based on our experience in supporting adoption of the Field Guide, capacity building about the procedures and objectives of water management is required both at the local and institutional levels. The National Water Commission has supported CAT to develop a ‘train-thetrainer’ workshop for people who will use the Field Guide. The workshops are held on location in remote communities and in regional centres. The workshop program covers the steps to creating a water management plan and outlines the core competencies for a facilitator. A facilitator must be able to communicate in cross-cultural contexts, identify the most appropriate management planning process and effectively draw on support agencies as required.

for robust water management planning, because microbial pathogens are most commonly present where humans live in close proximity to their livestock and other animals (Hrudy, 2004).

During the ‘train-the-trainer’ workshops and program implementation, the following issues have emerged:

3.

Sustainable water management. Program managers are keen to initiate water programs; however, implementing management programs that span more than a year remains difficult. Too often program leaders are eager to visit communities to test the water and relay the results to consumers, but they then do little more. A shift in understanding about water testing as a verification procedure within a broader management plan remains fundamental. Water testing is not the first activity that defines the approach. During implementation, reinforcement that water testing is a component of a holistic water management strategy to engage the local community and understand the water supply is the first step. Annual review. The importance of an annual audit or review is frequently overlooked by program managers. The annual audit or review is an integral part of the management process and is the opportunity to assess the system and management performance as well as integrate step-wise improvements. Water management in remote regions relies on shared management procedures, so the review can reinforce ongoing support structures and the maintenance of relationships. It is recognised that the sustainability of small supplies relies on input from institutions to ‘provide encouragement and motivation, monitoring, participatory planning, capacity building and specialist technical assistance’ (Harvey and Reed, 2007). Shared management, reliable support and technical advice must form the basis of a sustainable management plan. Shared management. There is strong evidence to support sharing management tasks for small water supplies (Grey-Gardner, 2008a). Microbiological contamination has the most acute health effects for consumers, so the most appropriate actions to prevent and respond quickly to a potential outbreak must occur on site. Local water managers are best positioned to carry out on-site surveillance that relates to reducing the microbiological hazards and risks (Hrudy, 2004). Outstations, where there are often small enterprise initiatives that involve stock and native wildlife living in and around the settlement, are a high priority

4.

Site selection. Water management planning is most successful when the community volunteers to participate. In most small settlements, residents do not pay for water and their contributions to management are driven by their determination to live on their traditional land. Residents need to fully participate in the planning process if the program is to be sustainable. Harnessing the skills, motivation and resources available in the local communities is first achieved by recognising the current contribution residents in small outstations already make to the operation and management of their water supply. Indigenous people are renowned for their high mobility and small settlements can be unoccupied for many months each year. Program managers often prefer to work with communities that are permanently occupied. The priority for developing water management plans only for communities that are permanently occupied denies communities with intermittent residency the skills to protect their water supply after prolonged absences, or to secure the supply before leaving. The willingness of residents to participate in water planning and carry out the local surveillance and management activities are key indicators to the impact of water management planning activities and should inform where programs are conducted.

5.

Step-wise improvement strategy. Many program managers hesitate to involve the community and create a management plan for fear of more capital investment needed for water system upgrades. Most remote water supplies have had significant investment in hardware, so a water management plan to maintain the reliability and integrity of the system will, in many cases, be the only investment required to ensure water meets the ADWG. It is preferable to begin a management plan regardless of the condition of the supply. In remote areas there are often substantial delays in completing capital works, so it is sensible to include them in a management plan as a step-wise improvement and monitor progress as part of the overall management plan.

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small systems The workshops are a medium to discuss and build understanding about successful and robust water management planning.

Conclusion Adoption of the Field Guide can assist with protecting the public health of people living in remote areas through increasing water system reliability, reducing water system breakdowns, and improving response rates to water system failures or emergency events. This can also reduce the demand and costs to service providers by reducing callouts. Approaching all-new water supply interventions with the view to engaging in shared water management will slow the whirlpool of crisis water supply management for service providers. The past mistakes of assuming that the issues surrounding small water supplies can be addressed through investing in high-capital cost programs, with little investment in understanding local community water needs and potential for contributions to management, can be avoided through investments in empowering and enabling communities to manage their water supplies. The benefits of small-community water planning by the health and water sectors have seen the production of resources such as the Field Guide to implement local management planning programs. The supporting ‘train-the-trainer’ workshops and ongoing advocacy assist to improve the approach to water management programming for remote Indigenous communities.

There is a growing body of evidence that the residents in small communities and outstations are prepared to engage in sustainable water supply management solutions. For policy makers, the goal now is to shift the reliance on performance data from infrastructure audits and water quality testing to performance in management procedures, to measure the sustainability of programs and stepwise water supply performance.

Acknowledgements Our work on the development of the Field Guide and the ‘train-the-trainer’ program was funded and supported by the National Water Commission.

The Authors

Robyn Grey-Gardner (email: robyngg@ ozemail.com.au) is an environmental and social scientist who has worked with small Indigenous communities on water supply management for more than 10 years. During the development of the Field Guide, Robyn was the project manager based at the Centre for Appropriate Technology. She is a consultant based in Alice Springs, NT. Ruth Elvin manages the Technical Resource Group at the Centre for Appropriate Technology (CAT). Her work with CAT has included overseeing the development of the National Indigenous

Infrastructure Guide, as well as applied research projects in Indigenous community housing and infrastructure. Peter Taylor is CEO of the Centre for Appropriate Technology – Australia’s National Indigenous science and technology NGO. He has worked for over 20 years in the Indigenous sector in government and non-government roles and has extensive experience in remote community infrastructure program delivery and policy development. dr Michele Akeroyd manages the Drinking Water R&D portfolio at Water Quality Research Australia. Her role includes ensuring that R&D investment is aligned with industry priorities and ensuring that the R&D outcomes have a pathway for communication and adoption. Michele also provides leadership in the development of corporate policies, strategy and stakeholder relations.

References Australian Government, 2009: The Community Water Planner Field Guide, National Water Commission, Canberra. Australian Human Rights Commission, 2009: Native Title Report, Chapter 6, Indigenous Peoples and Water, Aboriginal and Torres Strait Islander Social Justice Commissioner, Sydney. http://www.hreoc.gov.au/social_ justice/nt_report/ntreport08/pdf/chap6.pdf (accessed 20 July 2010). ABS, 2007: Housing & Infrastructure in Aboriginal & Torres Strait Islander Communities: Australia, 2006 (Reissue), Publication No. 4710.0, Australian Bureau of Statistics, Australian Government, Canberra.

Residents at Buru in Queensland map their water supply.

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small systems Beard N, 2009: Small water system reliability in remote Indigenous communities in the Kimberley, Research Report 49, Water Quality Research Australia, Adelaide. Davies J, White J, Wright A, Maru Y & LaFlamme M, 2008: Applying the sustainable livelihoods approach in Australia desert development, The Rangelands Journal, 30, pp 55–65. Federal Race Discrimination Commissioner, 1994: Water: A Report on the Provision of Water and Sanitation in Remote Aboriginal and Torres Strait Islander Communities, AGPS, Canberra. Grey-Gardner R, 2008: Remote Community Water Management, DKCRC Research Report Number 27, Desert Knowledge Cooperative Research Centre, Alice Springs. Grey-Gardner R, 2008a: Implementing risk management for water supplies: a catalyst and incentive for change, The Rangelands Journal, 30, pp 149–156. Grey-Gardner R, 2009: Community Water Planner Field Guide, Final report for the National Water Commission, Centre for Appropriate Technology and Water Quality Research Australia, Alice Springs. Harvey PA & Reed RA, 2007: Communitymanaged water supplies in Africa: sustainable or dispensable? Community Development Journal, 42, pp 365–378.

Hrudy SE & Hrudy EJ, 2004: Safe Drinking Water: Lessons from Recent Outbreaks in Affluent Nations, IWA Publishing, Cornwall, UK.

Stafford-Smith M & Cribb J, 2009: Dry Times: A Blueprint for a Red Land, CSIRO Publishing, Melbourne.

Human Rights and Equal Opportunity Commission, 2001: Review of the Water Report, HREOC Race Discrimination Unit, Sydney, Australia.

Taylor J, Brown D & Bell M, 2007: Population Dynamics and Demographic Accounting in Arid and Savanna Australia: Methods, Issues and Outcomes, Report of a Study for the Desert Knowledge and Tropical Savannas Cooperative Research Centres, Desert Knowledge Cooperative Research Centre Report 16, Alice Springs.

Kral I, 2010: Generational change, learning and remote Australian Indigenous youth, Centre for Aboriginal Economic Policy Research, Working Paper No. 68, Australian National University, Canberra. NHMRC, 2004: Australian Drinking Water Guidelines, National Health and Medical Research Council, Canberra. http://www.nhmrc. gov.au/_files_nhmrc/file/publications/synopses/ adwg_11_06.pdf (accessed 4 August 2010). Nicol A, 2000: Adopting a sustainable livelihoods approach to water projects: implications for policy and practice, Working paper 133, Overseas Development Institute, London. SCRGSP, 2009: Overcoming Indigenous Disadvantage: Key Indicators 2009, Steering Committee for the Review of Government Service Provision, Productivity Commission, Canberra. Stafford-Smith M, 2008: The ‘desert syndrome’ – causally linked factors that characterise outback Australia, The Rangelands Journal, 30, pp 3–14.

Warchiver I, Tjapangati T & Wakerman J, 2000: The turmoil of Aboriginal enumeration: mobility and service population analysis in a Central Australian community, Australian and New Zealand Journal of Public Health, Vol 24/4. WHO, 2010: Small and safe, Investing in small community water supplies will reduce waterborne disease outbreaks and overall costs, World Water Day 2010, World Health Organization, http://www.unwater.org/ worldwaterday/downloads/WHO_IWA/Small_ systems_WWD-20100316-V8.pdf (accessed 28 July 2010). Willis E, Pearce M, McCarthy C, Ryan F & Wadham S, 2009: The provision of water infrastructure in Aboriginal communities in South Australia, Aboriginal History, Volume 33 ANU E Press. http://epress.anu.edu.au/apps/bookworm/view/ Aboriginal+History+Volume+33/141/ch07.xhtml (accessed 28 July 2010).

Join a Water Capability Team Showcasing Australian capabilities and opening doors to customers The Water Supplier Advocate, the Department of Innovation, Industry, Science and Research and waterAUSTRALIA are creating 5 water industry capability teams with the following themes: • Irrigation Systems • Drinking Water • Water Recovery, Re-use and Treatment • Environmental Services • Water related IT Establishment workshops to be held in major capital cities in October 2011 For more information go to www.waterAUSTRALIA.org Register your interest – Sam.Ashby@waterAUSTRALIA.org

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small systems: industrial

Presentedatat presented

refereed paper

the poteNtIAl for MeMbrANe DIstIllAtIoN of INDustrIAl wAstewAters In-house waste heat can sometimes be used to recover high-quality water from a waste stream N Dow, M Duke Abstract This paper reports the first phase of a project to demonstrate the potential for the membrane distillation (MD) process to exploit waste heat from industry to treat saline effluent, producing high quality water for on-site reuse without an increase in greenhouse gas emissions. Five organisations in Melbourne’s industrial west were surveyed for participation in the project, including: a plastic foam producer; a frozen food producer; an electricity generator; a chemical manufacturer; and a plastics manufacturer. Three of the sites visited presented a number of possible streams that would benefit from MD treatment, possessing large sources of waste heat. Effluent samples from these sites were tested at bench scale to investigate potential membrane fouling and other site-specific process issues. Water recoveries during these experiments easily exceeded 90%, supporting the proposition that one of the benefits of MD is high recovery operation. Average initial permeate flux of 30–35 L/ hr/m2 declined over the duration of the experiments (between 25–150 hours) at rates dependent on feedwater quality. Some effluents experienced significant

membrane fouling, but were successfully managed by the addition of a small amount of antiscalant. The results of these experiments are presented here and were used to select one site, the electricity generator, for the site pilot trial. At this stage in the project, the pilot plant has been designed and built. The plant will operate unattended at the selected site, producing 10–20 L/hr of desalinated water for three months. Details of the plant are presented along with initial workshop trial data.

Introduction: Membrane Distillation Membrane Distillation (MD) is a process that was developed in the 1960s, but has recently aroused interest due to rising water and energy scarcity (Khayet, 2010). MD technology for water desalination differs from other membrane separation technologies in that the driving force for desalination is the difference in vapour pressure across a membrane, rather than total applied pressure as used in reverse osmosis. As vapour pressure is not significantly reduced at high salt concentrations, MD is particularly useful for treating high salinity effluent streams.

Permeate Vapour

Feed

Feed

Cold Water

Feed

Feed

Sweep Gas

Permeate Vapour

Permeate

78 SEPTEMBER 2011 water

Vacuum

Permeate

Membranes used for MD processes are hydrophobic, which Membrane Membrane Membrane Membrane provides a barrier Cooling plate for liquid water Pore Pore Pore but allows water Pore vapour to pass. As these membranes typically have large pores (0.1–1.0 µm), relatively low vapour pressure differences will produce large amounts of distilled permeate Sweep Direct (Tomaszewska, Air Gap Vacuum Gas Contact 2000). The MD MD MD MD vapour pressure difference across Figure 1. Membrane Distillation’s various configurations (Zhang the membrane is et al., 2008).

maintained by a flow of heated feedwater on one side of the membrane, and a flow of cooled permeate on the other. Therefore, the ultimate temperature of the feedwater is of less importance than the temperature difference between the feed and permeate sides of the membrane in determining distillation rate. It is these relatively low temperature demands that make MD an attractive desalination process. But work on MD has also risen recently as a result of the availability of low-cost, high-performance membranes produced from numerous suppliers worldwide (Zhang et al., 2008). In an MD process for desalination, hot feedwater is passed over the surface of these porous hydrophobic polymeric membranes. Water is evaporated into the pores of the membrane at the brine-membrane interface, which diffuses through the membrane where it condenses as permeate. Although there are different configurations of MD, the difference between them is the technique used to draw away and condense the vapour (decrease the vapour pressure). Figure 1 illustrates the four commonly used configurations of MD (Alklaibi et al., 2005). In a Direct Contact MD (DCMD) configuration, the permeate is also the cooling media and, consequently, is cycled around a semi-closed loop (the “cold or permeate cycle”) from which the product water is harvested. The effluent to be treated enters the “hot or feed cycle”, which is recycled through heating equipment. It is from this hot cycle that the brine concentrate is drawn and rejected. It is the utilisation of heat instead of electricity to desalinate water that illuminates the great potential of MD in addressing water and energy simultaneously. This heat can be low grade and so can easily be sourced from waste heat or a solar resource. Such low-grade heat is commonly rejected in many industrial operations, so its carbon

technical features


refereed paper

presented Presentedatat

debt has already been paid; yet this heat can be employed to drive the MD process and produce valuable high-quality water from saline waste streams. Therefore, by utilising this low- or zero-cost resource to treat effluent, the benefits of on-site water reuse, substituting precious potable water consumption and reducing discharge volumes to sewer, are possible. This study follows on from work presented at Ozwater’10 where an MD plant was designed, constructed and operated with support from GWMWater to desalinate groundwater using only solar-derived heat (Dow et al., 2010). This successful trial identified the potential for MD to treat varying quality industrial effluents with commonly available waste heat, and provided practical learning into membrane module design. One of the impediments to greater use of MD technology is the low availability of commercial modules incorporating suitable membranes. Consequently, the evolution in design and construction methods of production scale membrane modules are important aspects of this work.

Assessing the potential In partnership with City West Water, GWMWater, the Victorian Smart Water Fund and Water Quality Research Australia (WQRA), the present project seeks to examine the viability of the MD water treatment solution in an industrial setting by operating a pilot scale plant on a continuous basis for a number of months. The parameters of the demonstration were to treat between 10–20 L of saline effluent per hour, operate 24 hours a day and produce potable quality water. To this effect, a series of industries in Melbourne’s western suburbs were surveyed to identify opportunities where MD could treat effluent to reduce discharge volumes to sewer and recover water of potable quality, powered by their resident waste heat as low as 40°C. However, the capacity and efficiency of the plant is greatly influenced by the membrane module design, as feed and permeate flow dynamics along both sides of the membrane affect permeate flux. As such, the factors affecting the successful demonstration of an MD operation include: module design; temperature that the effluent can be heated to; and membrane fouling. The last two of these factors are largely site-specific; hence a thorough examination of potential sites is prudent. This paper represents the first phase in the larger project. Results of this survey

small systems: industrial

are presented and an assessment of the feasibility of MD effluent treatment for heavy industry is proposed. Details of an MD pilot plant designed for unattended continuous operation are also presented. Commissioning trials of the pilot plant were scheduled for July 2011, with the full trial completed by the end of the year.

throughout the duration of the test. Furthermore, the effluents were analysed using inductively coupled plasma spectroscopy and wet chemical analyses to assess parameters that influence MD performance including total organic carbon and metals content (refer to Table 1).

experimental and Methods

Five organisations in Melbourne’s west, operating different types of businesses, were approached for participation in the project. For each participant, discussions identified effluent streams that contribute the largest source of total dissolved solids (TDS) to the sewer discharge, or were the most challenging for trade waste management. These streams were targeted for assessment for potential MD treatment. Examples of the beneficial uses of MD treatment that emerged from this survey of a small geographical area were: 1) boiler or cooling tower blowdown treatment for direct return to the plant unit; 2) demineralisation of plant effluent, where the ion exchange resin regenerant solutions are combined and treated as a saline stream, reducing the volume directed to sewer or potentially applying a zero liquid discharge principle where the salt is captured for disposal off-site; and 3) neutralised caustic wash water, concentrated to recover useful water.

Demonstration site selection Identification of potential users of lowenergy desalination for effluent treatment was initially made by City West Water, the water authority servicing Melbourne’s industrial west. The authority selected a number of businesses from their customer base that would benefit from additional effluent treatment, have potentially useable waste heat, and were agreeable to research projects of this nature. One industry partner was then selected for the three-month on-site demonstration. The selection criteria included: availability of sufficient waste heat to raise effluent temperature to approximately 40–60°C; an effluent stream that will benefit from desalting treatment; and a stream that is fit for MD processes.

For a water treatment technology to offer a practical solution over the long term, plant reliability operating on actual industrial effluent needed to be thoroughly results of preliminary trials assessed. MD is a membrane separation The five businesses approached process and all membrane applications for participation in the project were face productivity losses from membrane distinctly different types of operations, fouling. Consequently, the selection yet all showed some potential for MD criterion of an “MD suitable effluent” treatment of their effluent streams. was examined on a laboratory scale The businesses surveyed were: (A) a apparatus to investigate aspects such as plastic foam producer; (B) a frozen food product water quality, short- and longproducer; (C) an electricity generator; term membrane fouling potential, and (D) a chemical manufacturer; and (E) a percentage water recovery limits. The labplastics manufacturer. However, site visits scale plant simulator was equipped with indicated that the food producer (B) and a 0.0169 m2 flat sheet membrane module the chemical manufacturer (D) had no constructed in-house, fitted with thin film microfiltration PTFE membranes (obtained Table 1. Water quality analysis. from Ningbo Chang-qi, Parameter Site (A) Site (C) Site (E) China), with 0.5 µm pH 6.8 7.7 7.4 pore size and bonded to a polypropylene scrim support layer.

TOC (mg/L)

23

5.5

26

TIC (mg/L)

<1

208

5.4

The apparatus used an electrically heated feed cycle and a refrigerated permeate cycle, and incorporated reservoirs holding approximately 10 L of feed and permeate. The permeate reservoir was positioned over an electronic balance to record permeate flux

Ammonia (mg/L as N)

-

38

-

Total Dissolved Solids (mg/L)

41

3490

1250

Calcium (mg/L)

4.6

7.1

84

<0.1

0.2

0.8

Iron (mg/L) Potassium (mg/L)

0.8

14

38

Magnesium (mg/L)

0.6

4.4

37

Phosphorus (mg/L)

1.5

<0.1

2.2

Zinc (mg/L)

0.9

<0.1

1.2

Silica (mg/L)*

<1

19

7

water

SEPTEMBER 2011 79


small systems: industrial easily accessible waste heat. The other three sites (A), (C) and (E) presented a number of possible streams that would benefit from a desalination process, and possessed some form of waste heat to drive the MD process. Samples of effluent collected from sites (A), (C) and (E) were introduced to the lab scale MD apparatus and operated in a manner to simulate a pilot or full scale plant concentrating the water sample. The apparatus was run until there was insufficient water volume to pump within the simulator. The main experimental goals were to investigate MD fouling or wetting, and to observe the level of water recovery that can be achieved before permeate flux declines unacceptably or salt precipitation limited further concentration. Further, filtration of the MD’s feed circuit to reduce the effect of precipitate forming on the membrane was achieved by placing an in-line filter immediately before the membrane module. The pore size of this filter was an important experimental parameter.

site A operation: Plastic foam production waste heat: Cooling water return (~60°C) wastewater: 1. Cooling tower blowdown to trade waste (24 kL/day at 200 mg/L TDS) 2. Boiler blowdown to trade waste (0.1 kL/d at 2000 mg/L TDS) MD treatment: Treat combined effluent streams, allowing the product water to be used as boiler feed or cooling tower make-up. Configure MD plant for very high recovery (~99%) with no reject stream entering the sewer. The MD performance of this effluent showed very little flux decline up to 80% recovery (Figure 2), but the small sample size limited testing to higher

Figure 2. Site A: Cooling tower water containing steam condensate – flux profile.

80 SEPTEMBER 2011 water

Presentedatat presented

refereed paper

recoveries. The very low salinity of this stream indicated recoveries up to 95% or higher are achievable. Although site management reported the effluent to be 100–200 mg/L TDS, the actual sample collected was 29 mg/L. There was very little presence of precipitate on the in-line filter at the conclusion of the test. The primary advantages of demonstrating MD technology on this site are: readily accessible heat and effluent; small site with good physical access to the cooling tower and sewer connections; and the potential to demonstrate a zero liquid discharge solution. The disadvantages include: effluent TDS may be too low to effectively demonstrate a desalination technique for a wider audience; and the site operates only Monday to Friday, which reduces the impact of a continuous trial.

site C operation: Electricity generation waste heat: 1. Low-grade heat from motor-cooling water (~35°C) 2. Heat from condensers (40°C) wastewater: Ion exchange resin regeneration effluent, neutralised, to trade waste (3000–4000 mg/L TDS) MD treatment: Treat effluent regenerant directly from effluent mixing tank, returning product water to regenerant make-up. Reject water to trade waste. The combined ion exchange regenerant effluent was a desirable stream to demonstrate a desalination process at 3500 mg/L TDS with few contaminants present. Flux decline began to be significant above 85% recovery, yet appeared to plateau at half the initial flux, even at 95% recovery (Figure 3). Permeate conductivity was observed to increase steadily from 30 µS/cm to 217 µS/cm, indicating some salt passage

Figure 3. Site C: Ion exchange resin regenerant combined effluent – flux profile.

Figure 4. Site C: Ion exchange resin regenerant combined effluent – permeate conductivity and ammonia profile. through the membrane. However, this industrial site uses an ammonia additive to combat corrosion and the feedwater sample was found to contain 38 mg/L (as N) ammonia. The suspicion that ammonia vapour would pass through the membrane into the permeate stream under MD conditions was confirmed with ammonia analysis of permeate samples collected throughout the run. Of the 1.4 g of ammonia contained in the initial volume of feedwater, 1.0 g was found in the total volume of permeate produced. The observed permeate cycle conductivity profile (Figure 4) closely matched that of the grab samples analysed for ammonia content, indicating transport of ammonia was the likely cause of permeate conductivity rise. This presents an interesting opportunity as the permeate was essentially pure water and ammonia. Further work to explore the viability of ammonia solution reused in the process is planned. Furthermore, ammonia removed from the waste stream will help with disposal management. The advantages of this site are: the effluent is very suitable for desalination, with high salt content at relatively consistent quality; and a demonstration performed on a power generation site would have significant potential for the power generation industry as a whole. Abundant low-grade heat at 40°C that must be discarded can now be used to produce large quantities of purified water. Preliminary calculations indicate that with the currently observed thermal efficiency of the MD process, waste heat from this site has the potential to produce as much as 10 ML/day of treated water. Although this plant must reject its heat load via the condensers, the highly efficient configuration of the operation makes accessing this heat difficult for the purpose of our trial. However, we identified the cooling water pumps attached to the boiler as a more convenient source of waste heat for a pilot trial.

technical features


refereed paper

presented Presentedatat

small systems: industrial

pilot plant Design and Construction

Figure 5. Site E: Cooling tower blowdown – flux profile A citric acid CIP procedure occurred twice during the run. Subsequent MD of the concentrate from this run was found to be effective with commercial antiscalant addition.

site e operation: Plastics manufacture waste heat: 1. Steam ejector trap (low pressure steam) 2. Cooling water return (35–45°C) wastewater: Cooling tower blowdown to trade waste (~1300 mg/L TDS) MD treatment: Treatment of blowdown, returning product water to cooling tower make-up. Reject to trade waste. This effluent showed signs of membrane fouling during the test run, which became significant at high feed concentrations (Figure 5). Initially, iron precipitates were suspected as the likely foulant. This type of precipitate is known to be very difficult to manage with filtration, but can be removed using an acidic clean-in-place (CIP) routine. However, later in the test an acid-insoluble material deposited on the membrane, which reduced flux dramatically (potentially a silica scale). Therefore, a further MD performance test was carried out using the concentrated feedwater and an addition of Flocon 260 antiscalant at 3 mg/L. With the Flocon 260 addition, MD performance of the concentrated cooling tower water achieved >90% recovery and stable flux at 15 L/hr/m2 for a duration of approximately 20 hours. These results indicate that the use of Flocon 260 is effective in combating this type of membrane fouling. The advantages of performing an MD demonstration on this site are: readily accessible heat sources (vented steam, cooling water return); and consistent effluent water quality that is typical of many industrial settings.

From the assessment process outlined above, Site C (the electricity generator) was selected to host the plant demonstration, and a formal approval process for site access was commenced. Occurring concurrently with activities to identify a suitable site was the construction of the demonstration plant. Although some MD equipment manufacturers are emerging, for example, from Medea AB in Sweden, MD modules are not costly to build when designed correctly. Consequently, an MD module was designed and constructed using VU’s expertise on optimal heat and mass transfer of MD at a scale tailored to meet the project’s objectives (Zhang et al., 2011). Our previous experience of membrane module design (Dow et al., 2010] had shown that rectangular flat sheet PTFE membranes configured in a multilayer arrangement produced good MD performance in a compact package. Furthermore, multilayer configurations enable customisation of the total membrane area by simple alteration of the number of layers installed to meet the required capacity. The present design evolved from our previous solar driven version, with refinements that has led to a two- or three-fold increase in permeate flux, reduced backpressure and lowered membrane area. Our ongoing work in this area continues to optimise the efficiency, which ultimately leads to more water produced, with less heat added. We are also developing the means to reduce the need for the electric pumps. Our trial will allow us to properly determine the energy efficiency which is not conveniently measured at the bench scale. The membrane module was then integrated into a plant capable of continuous unattended operation. The plant was constructed on three skids incorporating a plate heat exchanger to collect local heat sources and a fan-driven cooler to exhaust heat from the permeate cycle. To combat membrane fouling and the likely formation of precipitate in the module, filtration equipment was installed on the feed cycle. It was anticipated that during weeks of continuous operation, management of salt precipitation and scale formation would occupy a large proportion of the process control effort. Consequently, a three-tiered filtration regime was developed that would deliver flexibility of pore size and capacity to match the prevailing particle load. The filtration equipment consisted of a bag filter (either 25 or 5 µm pore

Figure 6 Simplified schematic of pilot plant. size), followed by a cartridge filter (~5 µm pore size), followed by a second, smaller cartridge filter (1 µm absolute pore size). Each of the filtration units could be bypassed or changed to a more appropriate pore size element. See Figure 6 for a simplified schematic of the pilot plant and Figures 8 and 9 for photographs of the plant prior to assembly. The pilot plant specifications are:

plant overview • Design flux = 20–30 L/hr/m2 • Plant capacity = 240 – 480 L/day (if running 24 hrs) • Heat = waste heat at 50–60°C

Membrane module • Module type = DCMD, flat sheet • Membrane type = PTFE, 0.5µm pore size • Total membrane area = 0.67 m2

heating • Waste heat tapped from boiler pumps

pilot plant Capacity testing The completed pilot plant was trialled at Victoria University’s Werribee pilot facility to ensure design capacity and process control mechanisms meet requirements in preparation for relocation to the selected site. A synthetic feedwater of 15g/L Sodium Chloride was introduced to the plant, operating with electric heating of the feed cycle and tap water cooling of the permeate cycle. Starting a low water recovery of 35%, this was increased on two occasions over the seven-day uninterrupted test to approximately 72%. Figure 7 shows the results of water produced each day along with concentrations of feed and permeate cycles. The results indicate the % water recovery control logic operates effectively, and that permeate flux appears to be stable and salt rejection was 99.96%.

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SEPTEMBER 2011 81


small systems: industrial

Presentedatat presented

power station will be significant for the progress of MD worldwide – taking it from the bench to a real water saving opportunity. The trial outcomes will allow for the estimation of the economic and practical viability of MD as a treatment option for wastewater minimisation and water recovery without the increase of greenhouse gas emissions.

Figure 7. Pilot plant capacity testing. Vertical arrows indicate an increase in % recovery set-point.

Conclusion This work demonstrates that MD with heat derived from waste sources could be a viable treatment technology for industrial effluent to reduce discharge volumes to sewer and recover water of potable quality without an increase in greenhouse gas emissions. For the purposes of this trial, it was apparent that the suitability of waste heat-driven MD at an industrial process depends on access to the available heat, which was found to be unique to each location. The water recoveries reached in laboratory experiments demonstrated that greater than 90% recoveries are achievable and membrane fouling can be managed (eg, with the addition of antiscalants and acid cleaning). However, maximum recovery sustained over a longer duration will now be determined. The permeate produced was of consistently high quality regardless of the feedwater quality, except for the situation where ammonia was present and passed through to the permeate. This presented an interesting opportunity to recover ammonia from the waste stream into the pure water permeate. Construction of the 240–480 L/day pilot plant is now complete and waiting to commence the demonstration phase of the project at Site C, the electricity generator. The three-month trial at a

Figure 8. MD pilot plant, pump side.

82 SEPTEMBER 2011 water

Acknowledgement The authors would like to acknowledge the financial support of the Victorian Smart Water Fund and Water Quality Research Australia.

the team This project involves an expert team in water treatment, membranes, thermodynamics and innovative technologies. Apart from the principal authors of this article the following are also authors of the Ozwater’11 paper. stephen Gray is Director of the Institute for Sustainability and Innovation, Victoria University, Melbourne, Victoria. Jun De li is a senior lecturer at Victoria University, Melbourne, Victoria. Audra liubinas is Co-ordinator – Business Resource Efficiency, City West Water. rohan barron was a Cleaner Production Consultant for City West Water, but has since left that organisation. eddy ostarcevic is the Principal of Integrated Elements, which serves to advise and deliver innovative water treatment systems to industry.

refereed paper

the Authors

Noel Dow (email: Noel.dow@vu.edu.au) is a researcher with Victoria University’s Institute for Sustainability and Innovation, and has been involved in the development of membrane distillation modules and associated laboratory and pilot plant equipment for a number of years. Mikel Duke (Mikel.Duke@vu.edu.au) is a Principal Research Fellow at the Institute for Sustainability and Innovation, Victoria University, and is the Project Leader of this research. Associate Professor Duke has 11 years of experience developing innovative membrane systems and their materials to enhance sustainability in water, foods and energy.

references Alklaibi AM & Lior N, 2005: Membrane-distillation desalination: Status and potential. Desalination 171(2), pp 111–131. Dow N, Duke M, Zhang J, O’Rielly T, Li J, Gray S, Ostarcevic E & Atherton P, 2010: Demonstration of solar driven membrane distillation in remote Victoria. AWA Ozwater’10, March 2010, Brisbane, Queensland (paper P036). Khayet M, 2010: Membranes and theoretical modeling of membrane distillation: A review. Advances in Colloid and Interface Science 164, pp 56–88. Tomaszewska M, 2000: Membrane Distillation – Examples of Applications in Technology and Environmental Protection. Polish Journal of Environmental Studies 9(1), pp 27–36.

paul Atherton is Manager of Research and Regional Development, GWMWater.

Zhang J, Duke M, Ostarcevic E, Dow N, Gray S & Li J, 2008: Performance of new generation membrane distillation membranes. IWA Singapore Water Week Convention, Singapore, June 2008 (IWA 511).

David halliwell is Program Manager – Wastewater and Recycled Water, Water Quality Research Australia.

Zhang J, Li J & Gray S, 2011: Researching and modelling the dependence of MD flux on membrane dimension for scale-up purpose. Desalination and Water Treatment, In Press.

Figure 9. MD pilot plant (labelled).

technical features


stormwater treatment

refereed paper

NUTRIENTS AND SOLIDS REMOVAL BY AN ENGINEERED TREATMENT TRAIN Field evaluation of a gully pit insert and cartridge media filter M Wicks, N Vigar, M Hannah Abstract The performance claims for individual stormwater treatment devices is often open to debate, as much of the data available has not been subjected to robust scrutiny and/or the claims are unable to be replicated. The following article summarises the results from a field trial of two such devices: an EnviroPod® and a StormFilter®, arranged in series (or a ‘treatment train’) treating runoff from a small road catchment on Streets Creek, Kuranda, west of Cairns in Far North Queensland.

One storm was also analysed for an expanded suite of nitrogen analytes, which determined that more than half the load was in soluble form. Furthermore, results from the field trial and research project indicated that this treatment train system has the potential to achieve meaningful load reductions of Suspended Solids (up to 99%), Phosphorus (up to 70%) and Nitrogen (up to 45%) through the use of conventional screening, filtration and ion-exchange removal technologies.

Introduction Livingston and McCarron (1992) identified that pollution loads (gross pollutants, sediment and nutrients) in stormwater increase proportionally with the degree of urbanisation in the catchment. Most consent authorities in Australia have established pollution removal efficiencies to be achieved prior to discharge from the urban catchment (eg, NSW Department of

Environment and Climate Change (DECC) 2007 recommends Suspended Solids (SS) 85%, Total Phosphorus (TP) 65%, and Total Nitrogen (TN) 45%) and/or Event Mean Concentrations (EMCs) in any stormwater discharged into natural ecosystems (e.g. ANZECC 2000 recommends turbidity 2-15 Nephelometric Turbidity Units (NTU), TP 0.01 mg/L and TN 0.15 mg/L for river systems in tropical Australia). In general, each pollutant is removed from the water column using a specific physical, chemical or biological process. Arranging these processes in sequence provides a treatment train approach that addresses and treats the whole pollutant load. There is, however, a paucity of published peer-reviewed scientific information validating the removal efficiency of each element or device used within a treatment train – let alone the performance of the treatment train itself. The research referred to herein provides information to validate the performance claims of an EnviroPod® gully trap and a StormFilter ® cartridge arranged in series as a treatment train.

Photo: ©GooGle, ©Geoeye ©Whereis® sensis Pty ltd ©diGital Globe

This field trial complements an earlier research project undertaken on the same system by James Cook University. Data was collected from six storm events, predominantly during the dry seasons of 2008 and 2009, and includes simultaneous sampling of both the flow rate and water quality on the inflows to, and outflows from, the treatment train for a suite of particulate and soluble stormwater pollutants. Influent concentrations for both Phosphorus and Nitrogen were found to be half to

one-third of concentrations reported in the literature as typical for urban catchments in Australia.

Figure 1. Location of the Kuranda Test Site.

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SEPTEMBER 2011 83


stormwater treatment

refereed paper

Background This field trial follows a previous research project undertaken by the School of Earth and Environmental Sciences, James Cook University (JCU), as part of a wider investigation into the impacts of road runoff on the Kuranda Range Road watershed, near Cairns (Munksgaard and Lottermoser, 2008), which discharges into the sensitive environment of Streets Creek. JCU reported on the quality of the watershed’s receiving waters, the chemical characterisation of the road runoff and the performance of the system over four runoff events. JCU found that the system “had a high retention capacity for suspended sediment and by implication particulate metals”. Conversely, they reported that the “treatment train” had only a “modest retention capability for dissolved (filtered) metals”. In addition, JCU identified that the treatment train system was, in fact, responsible for a significant net export of zinc. On the basis of their data, nutrient levels in the road runoff were low, and do not constitute a water quality concern at Streets Creek. However, they also reported significant retention of both TN and TP. The JCU study, which, in their own words “do[es] not constitute a full evaluation of the EnviroPod/StormFilter treatment system”, found the system

Figure 2. Schematic of the SYSTEM treatment train. achieved substantial removal of Total Nitrogen (45%), Total Phosphorus (70%), Total Aluminium (71%), Total Nickel (73%), Total Lead (60%) and Total Copper (58%). On the other hand, it identified potential releases of Suspended Solids under 500 microns, as well as dissolved zinc and copper.

protection on the steel components. Given the substantial removal of suspended solids, nutrients and total metals, it appears unlikely that the dissolved copper and zinc, observed in the outflows, was associated with a release of the under-500 micron sediment fraction.

One explanation for the abovementioned releases is that they could be related to the anaerobic conditions present in either the standing water within the wet-sump or, in the case of zinc, corrosion of the exposed galvanised

It was largely to address these issues and better understand the sources of these copper and zinc releases that Stormwater360 undertook a further field evaluation of the treatment train system, which is the subject of this evaluation.

Table 1. Water quality analytical parameters. Parameter

Abbreviation

Analytical Method*

Units

Limit of Reporting

Analysed by

Electrical Conductivity

EC

APHA 2510B

µS/cm

1

Cairns Water

pH

pH

APHA 4500-H+

-

0.1

Cairns Water

Suspended Solids above 500 microns

SS > 500 micron

500 micron sieve & APHA 2540B

mg/L

1

Cairns Water

Volatile Suspended Solids above 500 microns

SS Vol. > 500 micron

500 micron sieve & APHA 2540E

mg/L

0.1% Dry Solids

Cairns Water

SS < 500 micron

APHA 2540B; equiv. ASTM D-3977-97

mg/L

1

Cairns Water

SS Vol. < 500 micron

APHA 2540E

mg/L

0.1% Dry Solids

Cairns Water

SS

Calculated

mg/L

-

-

Suspended Solids below 500 microns Volatile Suspended Solids below 500 microns Suspended Solids Volatile Suspended Solids

SS Vol.

Calculated

mg/L

-

-

Total Phosphorus

TP

APHA 4500-P

mg/L P

0.02

Cairns Water

Total Nitrogen

TN

APHA 4500-N

mg/L N

0.05

Cairns Water

Total Kjeldahl Nitrogen

TKN

Calculated

mg/L N

-

-

Ammonia Nitrogen (Ammonium Nitrogen)

NH3-N

APHA 4500-NH3

mg/L N

0.05

Cairns Water

NO3-/NO2--N

APHA 4500-NO3

mg/L N

0.01

Cairns Water

Total Organic Carbon

TOC

APHA 5310-B

mg/L

1

ALS

Dissolved Organic Carbon

DOC

APHA 5310-B

mg/L

1

ALS

Particle Size Distribution (Laser Diffraction)

PSD

Malvern Mastersizer S

micron

0.05

QUT

Nitrate/Nitrite (Total Oxidised Nitrogen)

84 SEPTEMBER 2011 water

technical features


stormwater treatment

refereed paper

VEE NOTCH WEIR PRESSURE TRANSDUCER

DRAIN

ROAD

OUTLET PIPE

SAMPLING TUBE

CHAN NEL

AUTOSAMPLER

Gross pollutants were not monitored as part of this study, although significant quantities were captured. Previous monitoring by White et al. (2001) demonstrated that the Enviropod® filter retained all (100%) litter up to an approach flow of 100L/sec.

AUTOSAMPLER FLOW METER

PLAN LAYOUT

Results and Discussion

Figure 3. Schematic of the sampling location.

Sampling Procedure and Equipment A graphical representation of the system is shown in Figure 2. The direction of flow through the gully pit insert (EnviroPod®) and into the cartridge media filter (StormFilter®) is shown in sequence from 1 to 4. The gully pit insert is intended to treat most flows and filter solids above 100 µm while containing contaminants in a dry state. After treatment by the gully pit insert, water is filtered radially through the media cartridge (outside to inside). The media cartridge had a nominal flow rate of 0.95 L/s (at 46 cm head, when the cartridge is primed) and a peak flow rate of ca. 1.3 L/s (at maximum 0.88 m head prior to bypass). The ZPGTM media used was a proprietary blend containing perlite (50%), granular activated carbon (GAC, 10%) and zeolite (40%). The system samples were collected using automated influent and effluent samplers (Figure 3), collecting continuous flow and precipitation data and water quality simultaneously. The influent sampler was programmed to send an SMS alert to Stormwater360, via the GSM cellular network, when the sampling program was triggered. A dial-up connection was then made to each sampler to download data for analysis. To qualify as a representative sample, the following criteria were specified. I.

II.

III.

IV.

Collection of at least three simultaneous influent and effluent samples per storm; Samples must have been collected while the treatment system operated within design flow rates (not in bypass); The sampled portion of the storm event must represent at least 60% of the storm total flow volume; A minimum of six data sets must be collected for a full performance evaluation.

Antecedent dry period was not identified as a constraint, due to the impervious nature of the catchment and the absence of a base flow; however, at least a three-day antecedent dry period was preferred. If the storm was deemed to qualify, Stormwater360 would inform Cairns Water and Waste Laboratory Services (Cairns Water, NATA accreditation # 14204) that samples required collection and analysis. Analysis was performed by Cairns Water and Waste Laboratory Services, ALS Laboratory Group – Brisbane (ALS, NATA accreditation # 825). All water quality parameters for qualifying storms were sent to an independent peer reviewer at Queensland University of Technology (QUT), ensuring transparency of data. Test methods for water quality analysis used for this study are provided in Table 1.

The system was installed at the Streets Creek site in March 2006 and remained an active treatment and sampling site for four years until being decommissioned in March 2010. Stormwater360 monitored the system from April 2008 to December 2009. During this time, the unit was maintained annually, prior to the onset of each dry season. Complete maintenance involved removing all sediments and debris from the system, gully pit insert and replacing the cartridge media. The gully pit insert required additional manual maintenance approximately once per year. Maintenance frequencies for the study were conducted in line with the systems standard operational lifecycle. Due to the nature of the catchment and size, there was an absence of a base flow or dry weather flows. Potential pollutant leaching of soluble contaminants was, however, still accounted for; organic debris left within the system was allowed to break down between maintenance periods and permitted to be sampled by the effluent sampler during storm events. A summary of the principal analytes sampled is contained in Table 2.

Suspended Solids ANZECC (2000), DECC (2007) and Fletcher et al. (2004) have identified suspended solids as a stressor of aquatic ecosystems. In addition, many of the other pollutants, such as metals, hydrocarbons etc, are transported attached to the suspended solids and sediment. The system achieved an SSC

Table 2. Summary of results. No. of events

Range of Influent EMCs (mg/L)

Median Influent EMC (mg/L)

Range of Effluent EMCs (mg/L)

Median Effluent EMC (mg/L)

Mean Removal Efficiency (Sum of Loads)

SSC

6

75 to 4384

1181

8 to 63

20

99%

SSC < 500 micron

6

48 to 180

105

8 to 62

20

78%

TP

6

0.08 to 0.19

0.123

0.02 to 0.15

0.055

47%

TN

6

0.6 to 1.5

1.045

0.2 to 0.9

0.615

44%

TKN

6

0.6 to 1.2

1.007

0.175 to 0.800

0.515

49%

Analyte

NH3-N

6

0.05 to 0.15

0.050

0.05 to 0.07

0.050

31%

TOC

6

3 to 16

7

3 to 10

5

32%

DOC

6

3 to 12

7

3 to 11

6

21%

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SEPTEMBER 2011 85


stormwater treatment

refereed paper

between 71 mg/L (forested catchments) and 232 mg/L (urban roads). Fletcher et al. (2004) recommend using a value of ca. 120 mg/L for roads and ca. 100 mg/L for most other land uses. Both sources propose a median value of ca. 40 mg/L for forested catchments. The influent concentration of Suspended Solids at Streets Creek is within the typical range of average annual EMCs proposed within the literature; however, no data was collected during large wet-season storm events. Consequently, the median influent EMC reported herein should not be regarded as indicative of an annual median value.

Figure 4. SS <500micron data (JCU + SW360). aggregate load reduction of 99%. SSC (ie, SSC is defined as the sum of SS <500 micron and SS >500 micron) is ‘suspended’ in the sense that all these particles were sufficiently suspended to reach the system. However, SS <500 micron represents what is more commonly understood by the term ‘suspended solids’. It excludes coarse settleable sediment, which, while being a management issue, does not represent such an acute threat to water quality. Figure 4 shows influent and effluent data (Stormwater360) for SS <500 micron, together with the results published by JCU. In the scatter plot, the filled-in circles represent data from the trial reported herein, and open circles represent data from the previous JCU’s research project. The exception is the JCU outlier represented as an open square, which has not been included in this evaluation. The line of best fit shown as a solid straight line was calculated by a least squares linear regression for all data points except the JCU outlier (intended to be informational only). Its relative slope provides an appreciation of the trend of the removal efficiency for the treatment train. The dotted curves represent the 95% confidence limits for these same data points. The true statistical significance of the regression lines is open to interpretation and requires further investigation, due to the limited number of data points available for this analysis. Over the six storms analysed by Stormwater360, the influent EMC for SS <500 micron was in the range of 48 to 180 mg/L with a median influent EMC of 105 mg/L. Duncan (1999) literature review determined that the median concentration for most land uses (roofs excepted) lies

86 SEPTEMBER 2011 water

Effluent EMCs recorded for SS <500 micron were in the range of 8 to 62 mg/L. The median effluent EMC was 20 mg/L. Mean removal efficiency for SS<500 micron, calculated by aggregate load reduction, was 78%. It is evident from Figure 4 that the Stormwater360 and JCU data sets are in relatively good agreement with each other, with the exception of the JCU outlier, which represents the first storm from JCU’s research project. This storm was deemed an outlier for all water quality parameters due to possible sampling errors and has been removed from the analyses. The box plot in Figure 4 shows that the combined dataset is also clustered around an influent EMC of ca.100 mg/L and an effluent EMC of ca.20 mg/L. In practical terms, 10 mg/L approximates the system’s irreducible EMC for under-500 micron suspended solids. The box plot in Figure 4 indicates that, over the course of two trials, the effluent EMCs from the system, were typically within the range of 10 to 40 mg/L.

Figure 6. Total Nitrogen (SW360 and JCU combined). Particle size distribution (PSD) by laser diffraction was performed for the SS <500 micron fraction for three storms during the Stormwater360 evaluation. Inspection of the three cases analysed consists of particles between ca. 10 microns and 200 microns in diameter. There is substantial variation between the three events. • Storm 2 influent PSD centred at ca. 20 microns for a removal efficiency of approximately 65%; • Storm 3 influent PSD centred at ca. 100 microns for a removal efficiency of approximately 85%; • Storm 6 influent PSD centred at ca. 35 microns for a removal efficiency of approximately 75%. Generally, the higher removal efficiency would be expected for the coarser samples, and this was the case for all three storms sampled.

Total Nutrients

Figure 5. Total Phosphorus (SW360 and JCU combined).

The system achieved an aggregate load reduction for total phosphorus (TP) of 47% (note, JCU recorded a load reduction of 70%), the median influent and effluent EMCs for TP were 0.123 mg/L and 0.055 mg/L respectively (refer to Table 2). Duncan (1999) and Fletcher et al. (2004) recorded EMCs within a similar range and Fletcher (2004) recommends mean TP concentrations of between 0.25 and 0.50 mg/L for most land uses. Similarly, BMP Database (2010) suggests that a typical range for TP concentrations in stormwater is from 0.11 to 0.38 mg/L, across a range of land uses. In this context it is apparent that the influent TP concentration at the Kuranda site is towards the very low end of published data. Consequently, the 47%

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Table 3. Nitrogen results from Storm 6. Phase

Analyte

Influent EMC (mg/L)

Effluent EMC (mg/L)

Mean Removal Efficiency (Sum of Loads)

TN

0.8

0.4

50%

TKN

0.8

0.34

58%

NH3-N

0.15

0.07

53%

Org-N

0.65

0.27

58%

NO3-/NO2--N

0.01

0.06

-500%

Total (dissolved and particulate)

TN

0.4

0.3

25%

TKN

0.39

0.23

41%

NH3-N

0.16

0.073

54%

Org-N

0.23

0.157

32%

NO3-/NO2--N

0.01

0.07

-600%

Dissolved

Particulate (by calculation)

TN

0.4

0.1

75%

TKN

0.41

0.11

73%

NH3-N

0

0

N/A

Org-N

0.41

0.11

73%

NO3-/NO2--N

0

0

N/A

reduction recorded in the Stormwater360 trial could be related to the difficulty in removing TP at very low influent EMCs, and a much higher removal rate (similar to the 70% recorded by JCU) could be expected as the influent EMC increased. The system achieved an aggregate load reduction for total nitrogen (TN) of 44%, while the median influent and effluent EMCs for TN were 1.045 mg/L and 0.615 mg/L respectively (Table 2). Again, this influent EMC is low with respect to most of the published data and, according to Duncan (1999), it correlates well with the median for data from forested catchments (0.95 mg/L), but is significantly lower than the median for roads (2.2 mg/L) or urban catchments (2.5 mg/L). Fletcher et al. (2004) recommends using a typical total nitrogen value of at least 2 mg/L for most land uses, with the exception of forested catchments. The total nitrogen results from JCU and SW360 are presented in Figure 6. The spread of influent EMCs is broad, but removal efficiency appears relatively consistent and substantial. This is in spite of the low influent concentrations. TN is generally considered to be predominantly soluble, which is best removed by

biological uptake or denitrification (in an anaerobic environment). Consequently, the consistent removal of TN exhibited by the system deserves further consideration. The majority (ca. 95%) of the total nitrogen load at Kuranda is TKN and a breakdown of TN species is contained in Table 3. A small proportion of this TKN load (ca. 5%) is ammonia nitrogen, which implies that ca. 90% of the total nitrogen load is present as organic nitrogen, in either soluble or particulate forms. An expanded nitrogen suite analysis was conducted for Storm 6, and filtered (0.45 micron) and unfiltered samples were processed in order to establish whether the removal processes, for this event, involved particulate removal or removal of dissolved species. Essentially, the entire TN load was present as TKN and ca. 20% of this was ammonia-N (Table 3). The entire ammonia-N load was soluble, and the treatment train system achieved 54% removal of this species. The remainder (ca. 80%) of the TN/TKN load was present as organic nitrogen, of which ca. 35% was dissolved. Overall, 73% removal of particulate organic nitrogen and 32% removal of dissolved organic nitrogen was achieved.

Given the removal efficiency for suspended solids, the high removal of particulate organic nitrogen is understandable. Removal mechanisms for dissolved organic nitrogen are less obvious. It is possible that there is some adsorption to the ‘schmutzdecke’ (bio-film) that develops on the cartridge; another possibility is removal under the anaerobic conditions within the standing water within the wet-zones, being the wet-sump and around the base of the cartridge. When runoff first enters the StormFilter®, it initially displaces the standing water in the wet-zones. Any pollutants in the standing water are sampled by the effluent sampler (once they have passed through the StormFilter® cartridge), but they are not sampled by the influent sampler. Furthermore, the last of the runoff to enter the cartridge during a storm event does not necessarily pass through the filter cartridge during that event and may be retained within the wet-sump until the next storm event, whereupon it is displaced. When the (particulate or dissolved) organic nitrogen converts to ammonia in the anaerobic wet sump, it can be removed as ammonia-N by the zeolite.

Table 4. Grab samples from wet sump. Antecedent Dry Period (days)

Report #

Diss. Cu (mg/L)

Diss. Zn (mg/L)

DOC (mg/L)

Diss. N (mg/L)

Diss. NH3-N (mg/L)

Diss. NOx--N (mg/L)

8

40627

0.011

0.053

17

-

-

-

20/02/2009

6

42998

0.001

0.016

-

2.4

2.39

<0.01

06/05/2009

19

43826

0.005

0.082

16

7.2

5.85

0.72

21/07/2009

79

44703

0.004

0.083

20

3.4

2.24

0.025

Date 07/07/2008

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stormwater treatment Periodic grab samples from the wet-sump indicate that most of the TN load in the standing water is present as ammonia-N at concentrations that are two orders of magnitude higher than typical influent ammonia-N concentrations. As such, ammonia-N is, possibly, generated in the wet-zones by anaerobic decomposition of organic nitrogen in the inter-storm event periods. This has two important implications: 1): the load of ammonia-N passed to the StormFilter® cartridge is significantly higher than is suggested by the influent EMC, which implies that the removal rates for ammonia-N removal may be an under-estimate; and 2): by converting organic nitrogen to ammonia-N in the wet-zones and then removing this ammonia, the system has the potential to remove soluble organic-N.

Discussion The results for Storm 6 represent a snapshot of one storm, and should not be considered as comprehensive; they do suggest, however, that the main TN removal pathways for the treatment train is the efficient removal of particulate organic nitrogen, complemented by the sorptive removal of soluble ammonia-N and organic-N. Very often TN removal is treated as a key performance benchmark for stormwater treatment practices. This is potentially problematic, given the apparent variation in the nature of the TN load. In a comprehensive study of nitrogen composition in Melbourne (Taylor et al., 2005), ca. 25% of the load was present as particulate organic nitrogen. The remainder was soluble and, of these species, oxidised nitrogen predominated over dissolved organic nitrogen and ammonia-N. Taylor et al. (2005) inferred that either ‘removing’ the water by infiltration or denitrification (ie, in the anaerobic zone of bio-retention practices) would be necessary to achieve significant TN reduction. Fletcher et al. (2004) reported that the TN composition measured in wet weather samples for various land uses in the Sydney and Illawarra regions was extremely variable. For urban catchments, median oxidised nitrogen concentrations were in the range 0.09 to 0.42 mg/L, while the median TN concentration range was 0.65 to 2.32 mg/L. The oxidised nitrogen represents a much smaller proportion of the TN load than was observed by Taylor et al. (2005) for Melbourne data. In a study of nutrient build-up on urban roads in the Gold Coast, Miguntanna et al. (2010)

88 SEPTEMBER 2011 water

found that oxidised nitrogen comprised only ca. 10% of the TN load, across three different land uses, and most of the TN load was present as TKN and a significant proportion of this was particulate in nature. Consequently, the measured TN load from the Gold Coast catchments is similar to that measured at the Streets Creek, Kuranda site, providing applicability of Nitrogen removals to various urban land uses.

Conclusions The results from this field trial generally correlate well with an earlier study at this site by JCU (Munksgaard and Lottermoser, 2008). The data collection from this study has been based on a rigorous and technically demanding monitoring program, which adds further credibility of the results (Goonetilleke, 2010). From an operational perspective, the system captured an appreciably large sediment load requiring annual cleaning to maintain its operational effectiveness. The EnviroPod®/StormFilter® treatment train achieved 78% removal for suspended solids under 500 microns, which approximates the long-term environmental target recommended by NSW DECC (2007), QLD DERM (2010) for South East Queensland (SEQ) and consistent with the 80% reduction target of many consent authorities in the US. The runoff at Streets Creek contained very low levels of phosphorus and nitrogen. Total Phosphorus removal was between 45% and 70% respectively in both the Stormwater360 field trial and the JCU research project, which approximates the NSW DECC (2007) and QLD DERM (2010) SEQ long-term environmental targets of 65% and 60% respectively, and is better than expected given the low influent EMCs. Total Nitrogen removal was consistent, substantial and in agreement with the NSW DECC (2007) and QLD DERM (2010) SEQ 45% long-term environmental target, despite the proximity of the influent EMC to the irreducible concentration of the treatment train. The removal of nitrogen was particularly noteworthy, given that the debris captured and stored within the treatment train was not included in the influent load into the system, but may have been sampled as a soluble leachate by the effluent sampler.

Acknowledgements The authors would like to acknowledge the support of and contributions by Professor Ashantha Goonetilleke and Geoffrey Hunter.

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The Authors

Michael Wicks (email: michaelw@ stormwater360.com.au) is Technical Director of Stormwater360 Australia. Nick Vigar is Research Manager and Mike Hannah is Technical Director, both of Stormwater360 New Zealand.

References ANZECC, 2000: Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Volume 1. The Guidelines. Tables 3.3.4-3.3.5 Tropical Australia p.3.3-12 and Table 3.3.5 p.3.3-13. National Water Quality Management Strategy, October 2000. BMP Database, 2010: International Stormwater Best Management Practices (BMP) Database Pollutant Category Summary: Nutrients. Prepared by Geosyntec Consultants Inc. and Wright Water Engineers Inc. (available from http://www.bmpdatabase.org). Duncan HP, 1999: Urban Stormwater Quality: A Statistical Overview, Report 99/3, Cooperative Research Centre for Catchment Hydrology, Melbourne, Australia. ETV (2004). Fletcher T, Duncan H, Poelsma P & Lloyd S, 2004: Stormwater Flow and Quality, and the Effectiveness of Non-Proprietary Stormwater Treatment Measures – A Review and Gap Analysis. Cooperative Research Centre for Catchment Hydrology, Technical Report 04/8. Goonetilleke A, 2010: Letter to Author, 15 March, 2010. Livingston EH & McCarron ME, 1992: Stormwater Management: A guide for Floridians. Florida DER (71 pages). Miguntanna NP, Goonetilleke A & Egodowatta P, 2010: Understanding nutrient build-up on urban road surfaces. Journal of Environmental Sciences, Vol 22(6), pp 806–812. Munksgaard NC & Lottermoser B, 2008: Treatment of Road Runoff Waters, Kuranda Range Project. Report for Queensland Department of Main Roads, School of Earth and Environmental Sciences, James Cook University, Cairns, Queensland, Australia. NSW Department of Environment and Climate Change (DECC, 2007): Managing Urban Stormwater: Environmental Targets. Consultation Draft – October 2007, Department of Environment and Climate Change NSW, p 4. QLD DERM, 2010: Urban Stormwater Quality Planning Guidelines 2010 – December 2010, Department of Environment and Resource Management, Table 2.2 SEQ (2010). Taylor GD, Fletcher TD, Wong THF, Breen PF & Duncan HP, 2005: Nitrogen Composition in Urban Runoff – Implications for Stormwater Management. Water Research, Vol 39, pp 1982–1989. White M & Pezzaniti D, 2001: Evaluation of Gully Pit Inlet Control Systems Project Number: 2368261, Urban Water Resources Centre, University of South Australia (20 pages).

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APPLICATIoN of CHLorINATIoN for CyANoBACTerIAL ToxIN CoNTroL Chlorination can be an effective final treatment barrier for a range of cyanotoxins L Ho, J Dreyfus, P Lambling, H Bustamante, T Meli, G Newcombe Abstract Filtered waters, prior to chlorine disinfection, were obtained from three wastewater treatment plants (WTPs), one in regional South Australia and two in Sydney. Samples were spiked with known concentrations of various cyanotoxins and treated with various doses of chlorine. The order of ease of cyanotoxin oxidation followed the trend, CYN > STX-eq > m-RR ≈ m-LR > m-LA. Under the conditions of this study the oxidation of microcystins was dependent on the chlorine dose in waters from plants in Sydney, with increased removal seen at a dose of 3.0 mg L-1. Increasing the dose from 1.5 to 4.0 mg L-1 did not have an impact on the oxidation of microcystins in the South Australian water.

Introduction Cyanobacteria (blue-green algae) are ancient organisms that have adapted and thrived in many environments, including drinking water sources. While they are thought to be one of the first organisms to produce oxygen and, hence, were possibly instrumental in creating the Earth’s atmosphere, their presence in drinking water sources has negative connotations for drinking water quality. This is predominantly due to their ability to produce secondary metabolites, in particular toxins that can affect human health. A majority of these cyanobacterial toxins (cyanotoxins) are not well removed by conventional water treatment (Mouchet and Bonnélye, 1998; Newcombe and Nicholson, 2004) and require either new and costly treatment technologies (eg, activated carbon, ozonation, membrane filtration) or optimisation of existing conventional treatment options. Of major concern in Australia are the cyanotoxins, cylindrospermopsin, microcystins and saxitoxins. Chlorination is considered a major treatment barrier for these toxins; however, little information

chlorine dosing and contact times, required to effectively oxidise these cyanotoxins. The CT values in this study were calculated by determining the area under a graph of chlorine concentration vs. time, different from the USEPA method of calculation which is essentially the residual chlorine concentration at a specific time (C, in mg L-1) multiplied by the specific detention time (T, in min) (USEPA, 2003).

has been gathered with respect to the effectiveness of this treatment for the oxidation of a range of cyanotoxins under conditions that would be experienced in Australian WTPs. While Merel et al. (2010) recently provided a review on the chlorination of a range of cyanotoxins, little has been published with respect to the chlorination of a range of cyanotoxins under equivalent conditions. This is particularly relevant since multiple classes of cyanotoxins are now being simultaneously detected in water bodies (Graham et al., 2010; Paerl et al., 2011).

Current State of Play in Cyanotoxin Chlorination Some information on the cyanotoxins studied, including their documented reactions with chlorine, is given below.

The efficiency of the chlorine oxidation process is dependent on a range of factors that are not limited to the chemical structure of the target compound, the water quality (in particular, pH and the presence of organics), the dose of chlorine and the reaction time. The main objective of this study was to identify the CT (the amount of chlorine exposed at a specific contact time) required to oxidise the cyanotoxins to levels equal to or below the Australian Drinking Water Guidelines (ADWG) and/or World Health Organisation (WHO) limits in three filtered waters, sourced from two WTPs in the Sydney area and one from a WTP in regional South Australia.

Cylindrospermopsin Cylindrospermopsin (CYN) is produced in Australia predominantly by the cyanobacterium Cylindrospermopsis raciborskii, and has been associated with serious tissue damage and cell necrosis in the liver, kidney and other organs (Falconer, 2005). In addition, studies have suggested that this cyanotoxin is carcinogenic, genotoxic and involved in the inhibition of protein synthesis (Froscio et al., 2001, 2003; Falconer, 2005). While no official guideline value exists for CYN, the WHO is in the midst of proposing a 1 µg L-1 level, due to concerns regarding the potential effect of CYN on human health (Rodriguez et al., 2007a). Figure 1 shows the structure of CYN.

This information will enable water authorities to identify and implement operational actions, such as optimising

-

O3SO H3C

H

OH

H

H

N

NH HN

O NH

+

NH

O

Figure 1. Structure of cylindrospermopsin.

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SEPTEMBER 2011 89


water treatment R4 R1 +

H2N

O H N N R2

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R1

R2

R3

STX

H

H

H

GTX2

H

H

OSO3

GTX3

H

OSO3-

H

Net Charge

Relative Toxicity

R4 = CONH2 (carbamate toxins)

N N

+

NH2

OH OH

R3

-

+2

1.000

+1

0.359

+1

0.638

R4 = CONHSO3 (n-sulfocarbamoyl (sulfamate) toxins) -

C1

H

H

C2

H

OSO3

-

OSO3-

0

0.006

H

0

0.096

Figure 2. Structural variations and characteristics of the saxitoxin class of cyanotoxins. The most well-documented incident where CYN had been implicated in affecting human health occurred in 1979 in Palm Island, Queensland, Australia (Hawkins et al., 1985). Over 120 people were reportedly poisoned by this toxin after treatment of C. raciborskii blooms in a drinking water source with copper sulphate, which caused the cyanobacterial cells to lyse, releasing large amounts of the toxin into the water body. A few studies have evaluated chlorine for CYN oxidation. Senogles et al. (2000) showed that chlorine was effective for the oxidation of CYN, provided a residual of 0.5 mg L-1 was present after 30 mins between pH 6–9. Rodriguez et al. (2007a, b) demonstrated that at pH 8, a chlorine dose of 1.5 mg L-1 was sufficient to completely oxidise CYN. However, these studies were unable to relate the oxidation of CYN under a practical water treatment situation and, in particular, determine the CT values required for effective CYN oxidation. A recent study by Ho et al. (2008) showed chlorine to be highly effective for the oxidation of CYN, with a CT value of 3 mg.min L-1 shown to be sufficient for complete CYN oxidation in two Australian drinking waters.

Figure 3. Structure of microcystin-LR.

90 SEPTEMBER 2011 water

Saxitoxins The saxitoxins are a group of potent alkaloid neurotoxins produced by cyanobacteria, predominantly Anabaena circinalis in Australia. These toxins act to block nerve cell sodium channels and can cause death if consumed in sufficient quantity (Kao, 1993). There are approximately 27 variants of this toxin, with the most common being the C-toxins, gonyautoxins (GTX) toxins and saxitoxins (STX). Of these three classes, the doubly-sulphated C-toxins are the least toxic, followed by the more potent singly-sulphated GTX variants and, finally, STX, which is non-sulphated and the most toxic. Although no guideline value exists for the saxitoxins, a provisional health alert value of 3 µg L-1 (as saxitoxin toxicity equivalents, or STX-eq) has been suggested by Fitzgerald et al. (1999) for the ADWG (NHMRC, 2004). The term STX-eq is commonly used, as this reveals the total toxicity of the water sample relative to the most toxic variant STX. To calculate STX-eq of a mixture of saxitoxins the toxicity of each toxin, relative to STX, is multiplied by its individual concentration in µg L-1. These values are then added to obtain the

toxicity of the mixture relative to STX. Expressing the combined toxicity in this form is more relevant from a health perspective, since each individual variant varies significantly in its concentration and toxicity level. The structure and relative toxicities of the variants are shown in Figure 2.

Studies on the chlorination of saxitoxins are sparse, and those that have been published have shown that saxitoxins could be effectively oxidised by chlorine provided the pH was above 8.0 (Nicholson et al., 2003; Senogles-Derham et al., 2003). The authors attributed this to the toxin molecule being present in an unprotonated form at a higher pH, and, therefore, more susceptible to oxidation, even though chlorine is known to be a weaker oxidant under these conditions. However, Ho et al. (2009) recently demonstrated that saxitoxins have greater susceptibility to chlorine in natural waters than has previously been reported (Nicholson et al., 2003; Senogles-Derham et al., 2003), with minimal difference in oxidation in the pH range between 7.3–8.0, suggesting that saxitoxin oxidation was not pH-dependent in the range likely to be experienced in a WTP. Efficient oxidation of the saxitoxins by chlorine was observed in two waters with CT values of approximately 30 mg.min L-1 required for greater than 90% oxidation of the saxitoxins, in terms of STX-eq (Ho et al., 2009).

Microcystins Microcystins are cyclic heptapeptide toxins that can be produced by a range of cyanobacteria. In Australia the most common cyanobacterium to produce microcystins is Microcystis aeruginosa. Over 70 variants of this toxin have been identified to date. One of the more toxic variants is microcystin-LR (m-LR), which is shown in Figure 3. The two structures that provide the most common variations are located at the arginine and leucine groups. These groups also give the variant its name (eg, m-LR, indicating Leucine and aRginine). The other variants evaluated in this study were m-LA (Leucine, Alanine) and m-RR (aRginine, aRginine). Their toxicity is usually associated with the conjugated diene on the Adda amino acid. Once absorbed by organisms they are accumulated in the liver, which can lead to haemorrhage and even death within a few hours. The potency of the microcystins, in particular m-LR, in humans was demonstrated in 1996 when 52 patients at two dialysis centres

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in Caruaru, Brazil, died as a result of acute hepatic failure. It was discovered that the water used for dialysis had been contaminated with microcystins, with concentrations of up to 600 ng mg-1 detected in the liver of victims (Yuan et al., 2006). As a result of the concerns about the effect of microcystins, a guideline value of 1 µg L-1 for m-LR in drinking water has been issued by the WHO. Similarly, the ADWG value for microcystins has been set at 1.3 µg L-1 as m-LR toxicity equivalents. A majority of the studies relating to the chlorination of cyanotoxins has focussed on the microcystins, and most of these have shown the microcystins to be sensitive to chlorination (Nicholson et al., 1994; Acero et al., 2005; Ho et al., 2006; Xagoraraki et al., 2006; Daly et al., 2007) with CT values <30 mg.min L-1 shown to be sufficient for effective oxidation. Furthermore, Ho et al. (2006) documented that various microcystin analogues reacted differently with chlorine with the ease of oxidation following the trend, microcystin-YR > m-RR > m-LR > m-LA. This trend was in agreement with published data on model compounds and free amino acids, suggesting that the reaction of chlorine was dependent on the amino acid side chains of the various microcystin variants.

experimental Methods Waters studied Filtered waters were obtained from three WTPs, one from regional South Australia (Plant A) and two from the Sydney area of New South Wales (Plants B and C). For chlorination experiments, waters were obtained after filtration but prior to chlorine disinfection from the respective WTPs. Characteristics of the waters are shown in Table 1.

Materials and analyses Experiments were conducted using purified CYN (95% pure), which was isolated from a laboratory culture of C. raciborskii (Palm Island, Queensland, CYP020). The toxin was dissolved in ultrapure water (Millipore Pty Ltd, USA) and stored at –20°C prior to use. Aliquots were taken from the CYN stock solution and dosed into experiments at specified concentrations. Prior to high performance

liquid chromatographic (HPLC) analysis, CYN was concentrated from sample waters by solid phase extraction using methods described previously by Metcalf et al. (2002). An HPLC system consisting of a 600-pump controller, 717-plus autosampler and 996 photodiode array detector (Waters Pty Ltd, Australia) was employed. Sample volumes of 50 µL were injected into a 150 x 4.6mm Apollo C8 column (Alltech, Australia) at a flow rate of 0.6mL min-1. Full details of the method are given in Ho et al. (2008). Concentrations of CYN were determined by calibration of the peak areas (at 262 nm) with that of a certified reference standard (Institute of Marine Biosciences, National Research Council, Canada). The method has a detection limit of 1 µg L-1. Five saxitoxin variants were used in this study: C1, C2, GTX2, GTX3 and STX. These were extracted and purified from a natural bloom of A. circinalis that occurred in Myponga Reservoir, South Australia. The purified toxin solution had a profile characteristic of Australian strains of A. circinalis where the variants C1 and C2 were predominant with smaller quantities of GTX2, GTX3 and STX variants (Velzeboer et al., 2000). A commercially available enzyme-linked immunosorbent assay (ELISA) (Abraxis, USA) was employed for the analysis of saxitoxins. The concentrations of the samples are determined by interpolation using a standard curve constructed with each run. A full description of the analysis is available on the website (www.abraxiskits.com). Results were expressed as saxitoxin toxicity equivalents, STX-eq. The method has a detection limit of 0.015 µg L-1 (as STX-eq). Purified m-LR, m-LA and m-RR were obtained from a commercial supplier (Sapphire Bioscience Pty Ltd, Australia) and individually dissolved in ultrapure water to prepare stock solutions. Aliquots from the stock solutions were then dosed into sample waters at the desired concentrations. Prior to analysis the microcystins were concentrated from sample waters by C18 solid-phase extraction according to the methods described by Nicholson et al. (1994). An HPLC system consisting of a 600pump controller, 717-plus autosampler and 996 photodiode array detector (all

Table 1. Characteristics of the sample waters tested.

Chlorination experiments A chlorine stock solution was prepared by bubbling gaseous chlorine through ultrapure water in a glass flask. The flask was then sealed and stored at 4°C overnight prior to use. Chlorine stock concentrations and free chlorine residuals were determined using the DPD-FAS titrimetric method described in Standard Methods (Method Number 4500-Cl F, APHA et al., 1998). Typical chlorine stock solution concentrations ranged from 3–5gL-1 as free chlorine, and these were determined by the DPD-FAS titrimetric method. All chlorination experiments were conducted in 500mL glass amber bottles at room temperature (25°C). For chlorine decay experiments, the filtered waters (spiked with the cyanotoxins) were dosed with chlorine and aliquot samples taken at various time intervals for free chlorine residual determinations. Combined chlorine residuals were not measured because ammonia concentrations for both treated waters were below the detection limit of 0.1 mg L-1 ammonia as determined by the titrimetric method outlined in Standard Methods (Method Number 4500-NH3 C, APHA et al., 1998). Chlorine exposure or CT values were calculated by determining the area under the plots of chlorine concentration versus time. For cyanotoxin chlorination experiments, the filtered waters were spiked with the cyanotoxins prior to chlorination. Chlorine was added from the chlorine stock solution to obtain the desired doses. Samples were quenched at various time intervals with sodium thiosulphate at a stoichiometric ratio specified in Standard Methods (Method Number 5710 B, APHA et al., 1998). These quenched samples were subsequently analysed for the cyanotoxins.

results and Discussion

DOC (mg L-1)

UV absorbance at 254nm (cm-1)

SUVA (L mg-1 m-1)

pH

Plant A

2.7

0.045

1.7

7.7

Plant B

3.1

0.053

1.7

7.6

Plant C

3.0

0.045

1.5

7.9

Water source

from Waters Pty Ltd, Australia) was employed for microcystin analyses. Sample volumes of 50 µL were injected into a 150 x 4.6mm Luna C18 column (Phenomenex, Australia) at a flow rate of 1mL min-1. Concentrations of microcystins were determined by calibration of the peak areas (at 238 nm) with that of external reference standards (Sapphire Bioscience Pty Ltd, Australia). The method has a detection limit of 1 µg L-1.

Chlorine decay Chlorine decay experiments were conducted with the three waters at doses of 1.5 and 2.0 mg L-1. In addition, a dose of 4.0 mg L-1 was applied in Plant A water as this is the average dose applied at this

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1000

3.5

200

0

3.0

0

50

100

150

200

250

300

350

400

Time (min)

2.5 1.5 1.0 0.5 0.0 0

50

100

150

200

250

300

350

400

Time (min)

Chlorination of saxitoxins

Figure 4. Decay of chlorine in waters from Plants A, B and C. Inset: CT plots for the respective chlorine decay curves. WTP. Results are shown in Figure 4, along with the corresponding CT values. The purpose of the chlorine decay experiments was to determine the free chlorine residual of chlorine in the waters at predetermined times so that the stoichiometric volume of quenching agent (sodium thiosulphate) could be added during the chlorination of cyanotoxins. In addition, the chlorine decay curves allowed for the calculation of the CT values. Only slight differences were evident between the waters when using chlorine doses of 1.5 and 2.0 mg L-1 with the chlorine consumption following the trend: Plant A ≥ Plant B > Plant C. This is reflected in the first-order decay rate constants shown in Table 2. The differences may be attributed to the water quality, in particular, the natural organic material (NOM) characteristics. Plant C water displayed the lowest specific UV absorbance (SUVA) values compared with the other waters; SUVA has been shown to correlate well with the conjugated and aromatic moieties in NOM and it

is these NOM constituents that are more susceptible to chlorine oxidation (Croué et al., 1999; Kitis et al., 2002). Furthermore, the slightly lower pH of Plants A and B waters (compared with Plant C water) may have also influenced the reactivity with chlorine, as the acid-base equilibrium favours hypochlorous acid, a stronger oxidant than the hypochlorite ion.

1.5

For the chlorination of CYN experiments, a chlorine dose of 1.5 mg L-1 was applied to the waters from Plants B and C, while a chlorine dose of 4.0 mg L-1 was applied in Plant A water; these represent the average chlorine dose applied at the respective WTPs. Two different initial concentrations of CYN (3 and 20 µg L-1) were evaluated in the three waters for the chlorination experiments; these concentrations were selected as they represent the concentration range detected in Australian water sources (McGregor and Fabbro, 2000). CYN has previously been shown to be highly susceptible to oxidation by

60

Plant A 4.0mg/L chlorine 3μg/L CYN 20μg/L CYN

40

0

0

100

200

300

Plant B

Plant C

4.0 x 10-5 (0.90)

4.1 x 10-5 (0.96)

2.5 x 10-5 (0.93)

2.0

2.6 x 10-5 (0.91)

2.8 x 10-5 (0.92)

1.8 x 10-5 (0.92)

4.0

2.4 x 10 (0.98)

-

-

400

500

600

CT (mg.min/L) 100

80

60

Plant B 1.5mg/L chlorine 3μg/L CYN 20μg/L CYN

40

20

0

0

20

40

60

80

100

120

140

160

CT (mg.min/L) 100

80

60

Plant C 1.5mg/L chlorine 3μg/L CYN 20μg/L CYN

40

20

Plant A

92 SEPTEMBER 2011 water

80

20

k (s-1)

-5

100

Chlorination of CyN

Table 2. First order rate constants (k) for the decay of chlorine in waters from Plants A, B and C. Correlation coefficients (R2) presented in parentheses. Chlorine dose (mg L-1)

The chlorination of saxitoxins was conducted using two initial STX-eq concentrations: 8 and 12 µg L-1. These

Percent toxin oxidised

4.0

400

Percent toxin oxidised

Free chlorine concentration (mg/L)

4.5

600

Percent toxin oxidised

5.0

800

CT (mg.min/L)

Plant A 1.5mg/L 2.0mg/L 4.0mg/L Plant B 1.5mg/L 2.0mg/L Plant C 1.5mg/L 2.0mg/L

chlorine (Rodriguez et al., 2007b; Ho et al., 2008) and the results in Figure 5 confirmed this. CYN was readily oxidised in the three waters with minimal difference observed between the two initial CYN concentrations. CT values of approximately 19, 7 and 7 mg.min L-1 were required to oxidise CYN to below 1 µg L-1 in waters from Plants A, B and C, respectively. These values are comparable to those reported in the literature (Ho et al., 2008). Furthermore, these CT values correspond to the first sample taken at 5 mins, so it is possible that efficient oxidation occurred at a time less than 5 mins, potentially translating to lower CT values required for efficient CYN oxidation. The susceptibility of CYN to chlorination can be attributed to its structure, in particular, the uracil moiety, which is also partially responsible for its toxicity (Banker et al., 2001). The reaction of uracil with chlorine is quite rapid, with a documented rate constant of 90 M-1 s-1 (Gould et al., 1984).

0

0

50

100

150

200

CT (mg.min/L)

Figure 5. Chlorination of cylindrospermopsin (CYN) in waters from Plants A, B and C.

technical features


water treatment

refereed paper

saxitoxin oxidation could occur, provided the pH was above 8.0. This finding is beneficial from a water treatment perspective as the pH of most Australian waters prior to disinfection is between pH 7.0 and 8.0.

Percent toxin oxidised

80

60

Plant A 4.0mg/L chlorine 8μg/L STX 12μg/L STX

40

100

80

Percent toxin oxidised

100

Chlorination of microcystins

20

100

200

300

400

100

Percent toxin oxidised

80

60

Plant B 1.5mg/L chlorine 8μg/L STX-eq 12μg/L STX-eq

40

20

0

50

100

150

200

250

CT (mg.min/L) 100

Percent toxin oxidised

80

60

40

Plant C 1.5mg/L chlorine 8μg/L STX-eq

20

In this study, the CT values required ranged from 47 mg.min L-1 (m-RR in Plant C water) to 245 mg.min L-1 (m-LA in Plant B water). In Plant B and C waters, the oxidation efficiencies of m-RR and m-LR were similar, while m-LA was more difficult to oxidise with chlorine. This

0 0

20

40

60

80

100

120

CT (mg.min/L) 100

80

Percent toxin oxidised

0

CT (mg.min/L)

0

Plant A 15μg/L m-LR 1.5mg/L chlorine 2.0mg/L chlorine 3.0mg/L chlorine 4.0mg/L chlorine

40

20

The initial concentration of the microcystins had minimal impact on their chlorination, similar to CYN and the saxitoxins (results not shown). Results using an initial concentration of 15 µg L-1 of each microcystin variant and the chlorine dose at each WTP are shown in Figure 7. The CT values required to oxidise the microcystins to below 1 µg L-1 were greater than those of previous studies where CT values of <30 mg.min L-1 were documented to be sufficient (Acero et al., 2005; Ho et al., 2006; Xagoraraki et al., 2006; Daly et al., 2007).

60

Plant B 15μg/L m-LR 1.5mg/L chlorine 2.0mg/L chlorine 3.0mg/L chlorine

40

20

0 0

50

100

150

200

250

300

350

400

350

400

CT (mg.min/L) 100

80

Percent toxin oxidised

0

60

60

Plant C 15μg/L m-LR 1.5mg/L chlorine 2.0mg/L chlorine

40

20

100

0

0

0

50

100

150

200

0

250

In waters from Plants A, B and C, CT values of 20, 13 and 7 mg.min L-1 were required for oxidation of the saxitoxins to below the ADWG health alert level of 3 µg L-1 as STX-eq, irrespective of the initial STX-eq concentration. These values are comparable to those reported by Ho et al. (2009) and Zamyadi et al. (2010). For oxidation to below 1 µg L-1 as STX-eq, CT values of 37, 33 and 7 mg.min L-1 were required in waters from Plants A, B and C, which is slightly higher than those for CYN in the same waters, suggesting that the saxitoxins are not as easily oxidised by chlorine as CYN. The susceptibility of the saxitoxins to chlorination in this study at relatively neutral pH (7.6-7.9) is consistent with Ho et al. (2009) and Zamyadi et al. (2010) and contradict those of Nicholson et al. (2003) and Senogles-Derham et al. (2003), who documented that efficient

100

150

Percent toxin oxidised

200

250

300

CT (mg.min/L)

60

Figure 8. Effect of initial chlorine dose on the oxidation of microcystin-LR (m-LR) in waters from Plants A, B and C.

Plant A 4.0mg/L chlorine 15μg/L each toxin m-RR m-LR m-LA

40

20

0 0

20

40

60

80

100

120

140

160

CT (mg.min/L) 100

80

Percent toxin oxidised

concentrations were evaluated in waters from Plants A and B, while only the 8 µg L-1 concentration was evaluated in Plant C water due to a limited supply of the saxitoxin material. Figure 6 shows results of the chlorination of the saxitoxins in the three waters using the chlorine doses applied at each of the respective WTPs.

60

Plant B 1.5mg/L chlorine 15μg/L each toxin m-RR m-LR m-LA

40

20

0 0

50

100

150

200

250

CT (mg.min/L) 100

80

Percent toxin oxidised

Figure 6. Chlorination of saxitoxins (as STX-eq) in waters from Plants A, B and C.

50

80

CT (mg.min/L)

60

Plant C 1.5mg/L chlorine 15μg/L each toxin m-RR m-LR m-LA

40

20

0 0

50

100

150

200

250

CT (mg.min/L)

Figure 7. Chlorination of microcystins, m-RR, m-LR and m-LA in waters from Plants A, B and C.

300

oxidation trend is similar to those reported previously and is attributed to the variable amino acid side chain moieties of the microcystin variants (Ho et al., 2006). It is unclear why the microcystins were more difficult to oxidise in this study compared with the previous studies, since the water qualities (eg, dissolved organic carbon, UV absorbance at 254 nm, SUVA and pH) were similar. Furthermore, the decay of chlorine in the waters in this study was not as rapid as those of previous studies (rate constants of ~10-5 s-1, compared with ~10-3 and 10-4 s-1). It is possible that the differences may be attributed to NOM-microcystin complexes being formed in the waters in this study, resulting in greater resistance to chlorine oxidation. Further work is required to support this contention. Additional chlorination experiments were conducted with the microcystins to determine if the initial chlorine dose had an effect on their oxidation. Results for m-LR are shown in Figure 8. Chlorine doses of 1.5, 2.0, 3.0 and 4.0 mg L-1 were evaluated in Plant A water, while doses of only 1.5 and 2.0 mg L-1 were evaluated in Plant C water. Each of the chlorine doses

water

SEPTEMBER 2011 93


water treatment in both plants showed nearly identical oxidation trends for m-LR. Similar results were obtained for m-RR and m-LA where the initial chlorine dose had no impact on their oxidation (results not shown). In contrast, the chlorine dose had an impact in the oxidation of m-LR in Plant B water (Figure 8). While the oxidation trends for the 1.5 and 2.0 mg L-1 doses were similar, the 3.0 mg L-1 dose resulted in more rapid oxidation of m-LR. Similar findings were evident for the other two microcystin variants (results not shown). This suggests that the higher chlorine dose applied in these waters may have satisfied the demand of the water, which consequently resulted in a greater reaction of chlorine with the microcystins.

Practical implications The application of the CT concept is historically used to determine the degree of appropriate disinfection of pathogenic organisms. For example, a CT value of >30 mg.min L-1 is recommended to inactivate 99% of Giardia (WHO, 1998). A summary of the CT values required to oxidise the cyanotoxins to below 1 µg L-1 in the three waters is shown in Table 3. In addition, the corresponding chlorine reaction times are presented. The ease of oxidation for the cyanotoxins followed the trend, CYN > STX-eq > m-RR ≈ m-LR > m-LA. With the exception of m-LA, a maximum CT value of approximately 106 mg.min L-1 would be required to effectively oxidise all cyanotoxins studied. For Plant B water, this would require a chlorine dose and reaction time of 1.5 mg L-1 and 120 mins, respectively. These conditions can be practically achieved in most WTPs, including the three evaluated in this study. If m-LA is present in the water source, longer reaction times would be required, up to 360 mins in Plant B water (a CT of 245 mg.min L-1).

Summary and Conclusions The main findings from this study are as follows: • Chlorination is an effective final treatment barrier for the reduction

refereed paper

of a range of dissolved cyanotoxins in finished water; • Over the range of cyanotoxin concentrations studied there was no significant impact of the initial cyanotoxin concentration on per cent oxidation; • The order of ease of cyanotoxin oxidation followed the trend, CYN > STX-eq > m-RR ≈ m-LR > m-LA; • Under the conditions of this study the oxidation of microcystins was dependent on the chlorine dose in waters from Plants B and C, with increased removal seen at a dose of 3.0 mg L-1. Increasing the dose from 1.5 to 4.0 mg L-1 did not have an impact on the oxidation of microcystins in Plant A water; • With the exception of m-LA, a maximum CT of 106 mg.min L-1 would be sufficient under all conditions to reduce cyanotoxin concentrations that could be expected in the filtered water to below 1 µg L-1; for m-LA, a maximum CT value of 245 mg.min L-1 would be required.

The Authors

Lionel Ho (Senior Research Officer) (email: lionel.ho@sawater.com.au), Jennifer Dreyfus (Research Officer) (email: jennifer.dreyfus@sawater.com. au) and Gayle Newcombe (Research Leader, Applied Chemistry) (email: gayle. newcombe@sawater.com.au) are with the Australian Water Quality Centre, South Australian Water Corporation. Paul Lambling was an intern student from the School of Chemistry, Physics and Electronics, Lyon, France. Heriberto Bustamante is a Project Manager (Science and Technology, Sustainability Division) with Sydney Water.

CT (mg min L-1) Plant A

Plant B

Plant C

CYN

19 (5 min)

7 (5 min)

7 (5 min)

STX-eq

37 (10 min)

33 (30 min)

7 (5 min)

m-RR

86 (20 min)

106 (120 min)

47 (40 min)

m-LR

86 (20 min)

106 (120 min)

68 (60 min)

m-LA

108 (30 min)

245 (360 min)

127 (120 min)

94 SEPTEMBER 2011 water

references APHA, AWWA & WEF, 1998: Standard Methods for the Examination of Water and Wastewater, 20th ed. American Public Health Association, American Water Works Association and Water Environment Federation, Washington, DC, USA. Acero JL, Rodriguez E & Meriluoto J, 2005: Kinetics of reactions between chlorine and the cyanobacterial toxins microcystins. Water Research 39, pp 1628–1638. Banker R, Carmeli S, Werman M, Teltsch B, Porat R & Sukenik A, 2001: Uracil moiety is required for toxicity of the cyanobacterial hepatotoxin cylindrospermopsin. Journal of Toxicology and Environmental Health A 62, pp 281–288. Croué JP, Debroux J-F, Amy GL, Aiken GR & Leenheer JA, 1999: Natural organic matter: Structural characteristics and reactive properties. In: Singer, P. (ed.) Formation and control of disinfection by-products in drinking water. American Water Works Association, Denver, Colorado, pp 65–93. Daly RI, Ho L & Brookes JD, 2007: Effect of chlorination on Microcystis aeruginosa cell integrity and subsequent microcystin release and degradation. Environmental Science & Technology 41, pp 4447–4453. Falconer IR, 2005: Cyanobacterial toxins in drinking water supplies: Cylindrospermopsins and microcystins. CRC Press, Boca Raton, Florida, USA.

Table 3. CT values required to reduce the cyanotoxins to below 1 µg L-1. Chlorine dose of 4 mg L-1 in water from Plant A and 1.5 mg L-1 in waters from Plants B and C. Chlorine reaction times for the respective CT values presented in parentheses. Cyanotoxin

Tass Meli is the Operations Manager – NSW & SEQ with TRILITY Pty Ltd in Australia.

Fitzgerald DJ, Cunliffe DA & Burch MD, 1999: Development of health alerts for cyanobacteria and related toxins in drinking water in South Australia. Environmental Toxicology 14, pp 203–209. Froscio SM, Humpage AR, Burcham PC & Falconer IR, 2001: Cell-free protein synthesis inhibition assay for the cyanobacterial toxin cylindrospermopsin. Environmental Toxicology 16, pp 408–412. Froscio SM, Humpage AR, Burcham PC & Falconer IR, 2003: Cylindrospermopsin-induced protein synthesis inhibition and its dissociation from acute toxicity in mouse hepatocytes. Environmental Toxicology 18, pp 243–251. Gould JP, Richards JT & Miles MG, 1984: The kinetics and primary products of uracil chlorination. Water Research 18, pp 205–212. Graham JL, Loftin KA, Meyer MT & Ziegler AC, 2010: Cyanotoxin mixtures and taste-and-odor compounds in cyanobacterial blooms from the Midwestern United States. Environmental Science & Technology 44, pp 7361–7368. Hawkins PR, Runnegar MTC, Jackson ARB & Falconer IR, 1985: Severe hepatotoxicity caused by the tropical cyanobacterium (bluegreen alga) Cylindrospermopsis raciborskii (Woloszynska) Seenya and Subba Raju isolated from a domestic supply reservoir. Applied & Environmental Microbiology 50, pp 1292–1295.

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water treatment

refereed paper

Ho L, Onstad G, von Gunten U, Rinck-Pfeiffer S, Craig K & Newcombe G, 2006: Differences in the chlorine reactivity of four microcystin analogues. Water Research 40, pp 1200–1209.

Mouchet P & Bonnélye V, 1998: Solving algae problems: French expertise and world-wide applications. Journal of Water Supply: Research and Technology – AQUA 47, pp 125–141.

Ho L, Slyman N, Kaeding U & Newcombe G, 2008: Optimizing powdered activated carbon and chlorination practices for cylindrospermopsin removal. Journal of the American Water Works Association 100, pp 88–96.

Newcombe G & Nicholson B, 2004: Water treatment options for dissolved cyanotoxins. Journal of Water Supply: Research and Technology – AQUA 53, pp 227–239.

Ho L, Tanis-Plant P, Kayal N, Slyman N, and Newcombe G, 2009: Optimising water treatment practices for the removal of Anabaena circinalis and its associated metabolites, geosmin and saxitoxins. Journal of Water and Health 7, pp 544–556. Kao CY, 1993: Paralytic shellfish poisoning. In Algal toxins in seafood and drinking water. IR Falconer (Ed), Academic Press, London, UK. Kitis M, Karanfil T, Wigton A & Kilduff JE, 2002: Probing the reactivity of dissolved organic matter for disinfection by-product formation using XAD-8 resin adsorption and ultrafiltration fractionation. Water Research 36, pp 3834–3848. McGregor GB & Fabbro LD, 2000: Dominance of Cylindrospermopsis raciborskii (Nostocales, Cyanoptokaryota) in Queensland tropical and subtropical reservoirs: Implications for monitoring and management. Lakes & Reservoirs: Research and Management 5, pp 195–205. Merel S, Clement M & Thomas O, 2010: State of the art on cyanotoxins in water and their behaviour towards chlorine. Toxicon 55, pp 677–691. Metcalf JS, Beattie KA, Saker ML & Codd GA, 2002: Effects of organic solvents on the high performance liquid chromatographic analysis of the cyanobacterial toxin cylindrospermopsin and its recovery from environmental eutrophic waters by solid phase extraction. FEMS Microbiology Letters 216, pp 159–164.

NHMRC, 2004: Australian Drinking Water Guidelines. National Health and Medical Research Council and the Natural Resource Management Ministerial Council, Canberra, ACT, Australia. Nicholson BC, Rositano J & Burch MD, 1994: Destruction of cyanobacterial peptide hepatotoxins by chlorine and chloramine. Water Research 28, pp 1297–1303. Nicholson BC, Shaw GR, Morrall J, Senogles P-J, Woods TA, Papageorgiou J, Kapralos C, Wickramasinghe W, Davis BC, Eaglesham GK & Moore MR, 2003: Chlorination for degrading saxitoxins (paralytic shellfish poisons) in water. Environmental Technology 24, pp 1341–1348. Paerl HW, Hall NS & Calandrino ES, 2011: Controlling harmful cyanobacterial blooms in a world experiencing anthropogenic and climatic-induced change. Science of the Total Environment 409, pp 1739–1745. Rodrıguez E, Onstad GD, Kull TPJ, Metcalf JS, Acero JL & von Gunten U, 2007a: Oxidative elimination of cyanotoxins: Comparison of ozone, chlorine, chlorine dioxide and permanganate. Water Research 41, pp 3381–3393. Rodrıguez E, Sordo A, Metcalf JS & Acero JL, 2007b: Kinetics of the oxidation of cylindrospermopsin and anatoxin-a with chlorine, monochloramine and permanganate. Water Research 41, pp 2048–2056. Senogles P, Shaw G, Smith M, Norris R, Chiswell R, Mueller J, Sadler R & Eaglesham G, 2000: Degradation of the cyanobacterial toxin

cylindrospermopsin, from Cylindrospermopsis raciborskii, by chlorination. Toxicon 38, 1203–1213. Senogles-Derham P-J, Seawright A, Shaw G, Wickramisinghe W & Shahin M, 2003: Toxicological aspects of treatment to remove cyanobacterial toxins from drinking water determined using the heterozygous P53 transgenic mouse model. Toxicon 41, pp 979–988. USEPA, 2003: Disinfection profiling and benchmarking. Technical guidance manual, Appendix B: CT tables, EPA 816-R-03-004. Velzeboer RMA, Baker PD, Rositano J, Heresztyn T, Codd GA & Raggett SL, 2000: Geographical patterns of occurrence and composition of saxitoxins in the cyanobacterial genus Anabaena (Nostocales, Cyanophyta) in Australia. Phycologia 39, pp 395–407. WHO, 1998: Guidelines for Drinking Water Quality. 2nd Edition, Addendum to Vol. 2, Health criteria and other supporting information. World Health Organisation, Geneva. Xagoraraki I, Zulliger K, Harrington GW, Zeier B, Krick W & Karner DA, 2006: Ct values required for degradation of microcystin-LR by free chlorine. Journal of Water Supply: Research & Technology – AQUA 55, pp 233–245. Yuan M, Carmichael WW & Hilborn ED, 2006: Microcystin analysis in human sera and liver from human fatalities in Caruaru, Brazil 1996. Toxicon 48, pp 627–640. Zamyadi A, Ho L, Newcombe G, Daly RI, Burch M, Baker P & Prévost M, 2010: Release and oxidation of cell-bound saxitoxins during chlorination of Anabaena circinalis cells. Environmental Science & Technology 44, pp 9055–9061.

Delivering innovative water, wastewater and reuse solutions.

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recycling

Presentedatat presented

refereed paper

RAPID CROSS-CONNECTION DETECTION BY PORTABLE FLUORESCENCE SPECTROSCOPY Recycled water is typically able to be distinguished from potable water by a factor of 4 to 5 AC Hambly, RK Henderson, A Baker, RM Stuetz, SJ Khan Abstract The implementation of dual reticulation systems for returning recycled water to the home for non-potable use is now common in new Australian housing developments. Managing the associated public health risk requires consideration of the potential for cross-connections between recycled and potable water pipes. While current protocols for detection exist, they are time consuming and cross-connections have occurred despite their implementation. Cross-connections may occur anywhere from a network to a singleproperty scale; hence, a highly sensitive, rapid and portable device is required for the detection of contaminated potable water. Fluorescence intensities at Îťex/em=300/350 nm have been previously shown to distinguish recycled water from potable water grab samples with a high degree of sensitivity and reliability using lab-scale equipment. To this end, this paper investigates two potential portable fluorescence systems, describing and discussing the results of in-situ fluorescence analysis programs undertaken at an Australian dual distribution system from the perspective of cross-connection detection.

Introduction Population increases and changing weather patterns have caused urban water management in Australia to increase its focus on the sustainability of water resources. As such, water recycling and reuse now play an essential role. New housing developments are increasingly incorporating dualdistribution or third-pipe systems, in which wastewater is treated offsite and redistributed back to households as recycled water for non-potable uses such as irrigation and toilet flushing. Within dual-distribution systems the potential exists for cross-connections between recycled and potable water

96 SEPTEMBER 2011 water

(Storey et al., 2007). Cross-connection incidences may damage public confidence in dual-reticulation schemes and even present a possible health risk to users, particularly if treatment failure or underperformance occurs. Incidences of cross-connection between potable and recycled water have been documented at Rouse Hill (de Rooy and Engelbrecht, 2003; Sydney Water, 2004), Newington (Sydney Water, 2005) and Pimpama-Coomera (ABC News, 2009), and although adverse health effects are yet to be officially attributed to cross-connection incidences in Australia (Storey et al., 2010), the inherent risk remains. In order to minimise this risk a rapid, highly sensitive method of detection is needed to ensure proper management of these networks. Within the water quality sciences, fluorescence spectroscopy has been investigated in natural, waste and polluted waters (Hudson et al., 2007) and has been utilised to characterise polluted river waters (Baker et al., 2003), detect tissue-mill effluent in rivers (Baker, 2002), determine organic matter removal efficiency within water treatment systems (Bieroza et al., 2010) and as a surrogate for biochemical oxygen demand (BOD) measurements (Reynolds and Ahmad, 1997; Hudson et al., 2008). The use of fluorescence spectroscopy has also been highlighted as having great potential as a monitoring tool in dual reticulation systems (Henderson et al., 2009), and has been supported by recent investigations into the fluorescence of static grab samples from within an Australian dual reticulation network (Hambly et al., 2010b). This study evaluated a number of water quality parameters for their ability to distinguish recycled water from potable water, such as conductivity and dissolved organic carbon, and found fluorescence to have the greatest potential, with a typical 10 times distinction. The ability for bench-

scale fluorescence analysis to distinguish between recycled and potable water samples has been verified by further studies at a number of other dual reticulation systems across Australia, which yielded similar results (Hambly et al., 2010a). Partial cross-connections may potentially occur within properties where only limited intrusion of recycled water into potable water supplies occurs. This mixture of recycled and potable water may also vary over time, depending on relative water supply pressures, so a high level of sensitivity is paramount in detecting cross-connections with a high confidence level. Monte-Carlo analysis of grab sample fluorescence using strict criteria required a greater than 45% intrusion of recycled water in potable water, whereas conductivity required a minimum of 70% intrusion to achieve the same confidence level (Hambly et al., 2010b). Static mixing of recycled and potable water samples shows a linear fluorescence response, making it possible to identify very low levels of recycled water in potable water. Hence, the current challenge is to investigate the potential for converting this highly sensitive analytical tool from a bench scale research tool to a portable engineering tool that is capable of capturing real-time in-situ data.

Methods Two in-situ trials were conducted between August and October 2010 at Rouse Hill Water Recycling Plant, which uses coagulation, dual media filtration, UV disinfection and chlorination to achieve its finished recycled water. The trials evaluated two portable fluorimeters: the SMF2 and the SMF4 (STS, UK) (Figure 1). SMF2 fluorescence data was recorded via a Datataker D80 data logger and downloaded using Delogger 5 software (v. 4.0.3.4), while SMF4 fluorescence data was recorded internally and downloaded using Terminal software (v. 1.9b).

technical features


refereed paper

recycling

presented Presentedatat

(A)

(B)

(Figure 2). Individual components of the flow-through system were connected by flexible 5mm diameter black polypropylene tubing, from which no significant fluorescent leaching was measured. Flow rates were dependent on the pressure of the water distribution systems and were observed to vary between 20mL.min-1 and 150mL.min-1. Portable fluorimeter baselines were established using a sealed cuvette of MilliQ water (Varian, Australia), and SMF2 and SMF4 fluorimeter data were obtained at five-minute intervals. Grab samples of potable water and the final product of recycled water were

5 minutes Fluorescence Measurements

30 minutes

1-2x Weekly

Figure 1. The SMF2 (A) and SMF4 (B) portable fluorimeters. SMF2 fluorimeters were employed between 20/08/2010 and 16/09/2010 to record a number of fluorescence emission regions between 190 and 450 nm. The fluorimeters utilise a xenon flash lamp with a broad excitation wavelength band between 280 and 300 nm, powered by a 9V lead-acid battery. The optimal ratio for distinction between the potable and recycled water sources was then observed to be at emission wavelengths of 300 nm/390 nm. SMF4 fluorimeters were employed between 20/09/2010 and 15/10/2010 and utilised a 280 (± 3) nm LED excitation source to record fluorescence at a single emission wavelength of 360 (± 3) nm. Both portable fluorimeters were connected to a 240V mains power supply during the in-situ trials; however, their internal power supplies typically allow for eight hours of operating time before recharging is required. Two identical fluorimeters and 3mL flow-through cuvettes (Lightpath Optical, UK) were employed within each trial – one connected to a recycled water flowthrough system and the other connected to a potable water flow-through system. Each system consisted of a fluorescence measurement, followed by conductivity and temperature measurements (HACH HQ40d) to account for any anomalies

1-2x Weekly

Figure 2. Flow diagram of experimental setup. (A)

also obtained on 13 occasions during the total study period, from each of which an excitation-emission matrix (EEM) was obtained to compare recycled and potable water quality with grab samples from previous research at the same site. No sample preparation was undertaken prior to running EEM analysis. Raw EEM spectra were obtained in 4mL quartz cuvettes (Starna, Australia) using a Cary Eclipse Fluorescence Spectrophotometer (Varian, Australia). EEMs were measured from 200 to 400 nm (excitation) and 280 to 500 nm at 5 nm intervals (emission), with excitation and emission slit widths of 5 nm at a photomultiplier tube (PMT) voltage of 800V and a scan speed of 9600 nm.min-1. The Raman intensity of water in a sealed cell (Varian, Australia) was measured at λex = 348 nm before each grab sample analysis to ensure instrument stability and was constant at 20 ± 1 arbitrary fluorescence units (afu) over the course of the study. EEMs were blank-subtracted using a sealed cuvette of MilliQ water (Varian, Australia), and locally generated emission and excitation correction factors were

(B)

Figure 3. Typical raw EEMs of (A) potable and (B) recycled water throughout the experimental period.

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SEPTEMBER 2011 97


recycling

Presentedatat presented

Table 1. Fluorescence intensities at λex/em= 300/350 nm from grab samples over the experimental period.

refereed paper

Table 2. Fluorescence intensities at λex/em= 280/360 nm from grab samples over the experimental period.

λex/em= 300/350 nm

λex/em= 280/360 nm

Date

Potable (afu)

Recycled (afu)

Recycled/ Potable

Date

Potable (afu)

20/08

18.8

105.8

5.6

20/08

23/08

19.2

123.5

6.4

23/08

26/08

17.3

157.3

9.1

30/08

18.8

138.7

7.4

03/09

13.7

144.5

10.5

06/09

18.4

172.1

10/09

16.2

124.1

13/09

20.5

20/09

22.2

23/09

Recycled (afu)

Recycled/ Potable

16.2

79.4

4.9

16.1

106.1

6.6

26/08

17.9

128.6

7.2

30/08

16.3

106.1

6.5

03/09

16.4

120.5

7.3

9.4

06/09

21.4

132.7

6.2

7.7

10/09

15.1

108.6

7.2

151.3

7.4

13/09

17.5

150.3

8.6

153.9

6.9

20/09

14.9

125.4

8.4

16.0

100.0

6.25

23/09

20.0

77.9

3.9

30/09

16.3

160.1

9.8

30/09

22.2

125.7

5.7

05/10

18.7

167.0

8.9

05/10

22.4

124.3

5.5

08/10

14.9

140.8

9.5

08/10

22.0

111.8

5.1

applied. All EEM data correction was carried out using Matlab software (Mathworks).

Results and Discussion Grab samples: Cary Eclipse Spectrophotometer The raw EEM spectra illustrated clear differences between the fluorescence character of recycled water and potable water samples (Figure 3). Recycled water samples exhibited high fluorescence in the humic-like (emissions centred around λex/em= 325/425 nm and λex/em= 230/425 nm) and protein-like (centred around λex/em= 300/350 nm and λex/em= 230/350 nm) regions. Potable water was typically observed to have much lower fluorescence intensities across the entire EEM, particularly within the protein-like region. The grab samples taken within this study agree with previous research,

which found clear distinctions of typically 10 times between recycled and potable water samples when analysed at λex/em= 300/350 nm on a benchtop fluorescence spectrophotometer (Hambly et al., 2010b). Fluorescence intensities at λex/em= 300/350 nm were also similar to previous sample studies, varying between 100 and 175 afu for recycled water, while potable water varied between 13 and 22 afu (Table 1). Fluorescence intensities within the range of the SMF4 spectrometer (λex/em= 280/360 nm) were typically lower than at λex/em= 300/350 nm, ranging from 79 to 150 afu, and potable water varied from 15 to 22 afu. The fluorescence ratio of recycled water/potable water was also typically observed to be slightly lower at λex/em= 280/360 nm (4.9 to 8.6) than at λex/em= 300/350 nm (5.6 to 10.5) (Tables 1 and 2).

Figure 4. Conductivity and temperature of recycled and potable water during In-situ Trial 1.

98 SEPTEMBER 2011 water

Data obtained from the grab samples are in agreement with earlier work (Hambly et al. 2010b), indicating that a significant distinction between recycled and potable water should still be possible by fluorescence analysis.

In-situ Trial 1: SMF2 Fluorimeter Conductivity was observed to vary between 236 and 251 μS.cm-1 for potable water and between 226 and 1049 μS.cm-1 for recycled water. Although the conductivity range of recycled water was quite different from earlier grab sample analysis (where conductivity was found to typically vary between 867 and 1045 μS.cm-1 for recycled water), it was typically between 900 and 1050 μS.cm-1, but decreased markedly on a number of occasions (Figure 4). The recycled water distribution system supplied by Rouse Hill Water Recycling Plant is occasionally topped up with potable water when

Figure 5. SMF2 fluorescence ratio (emission 300/390 nm) of recycled and potable water during In-situ Trial 1.

technical features


Contaminants of Concern in Water 8 - 9 November 2011, Mercure Hotel, Sydney NSW

Registrations now open! Are you across emerging technological solutions that deal with contaminants of concern in water? Do you want to know more about new and emerging water contaminants? Register for AWA’s Contaminants of Concern Conference and gain a greater understanding of the real and perceived risks that arise from diversification of water source options. Keynote Speakers • Anders Baum, Professor, Head of Innovation, Environment, Nano, Technical University of Denmark • Yu Jung Chang, National Director of Water Treatment, HDR, USA Conference Themes • Chemical, microbial, natural and synthesised contaminants in water. • Impacts of contaminants on the aquatic environment and treatment processes. • Emerging contaminants which pose a risk to human and environmental health. • Treatment process modifications to deal with contaminant threats. Who should attend? This conference is relevant to water utility managers, water quality scientists, regulators, analytical laboratory technicians and scientists, health officers, consultants, water catchment officers, researchers and academics, and Local Government officers.

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recycling

Presentedatat presented

Figure 6. Temperature and conductivity of recycled and potable water during In-situ Trial 2.

Figure 7. SMF4 fluorescence (in afu) at λex/em= 280/360 nm for recycled and potable water during In-situ Trial 2.

required; however, no potable water top-ups occurred during these trials.

good stability and ranged from 230 to 260 μS.cm-1 (Figure 6).

Potable water was observed to have a temperature range between 17 and 20˚C, whereas recycled water was observed to vary between 10 and 24˚C. Both water sources displayed diurnal variation in accordance with local environmental temperature and is most likely indicative of plumbing network differences between the two water sources. For both conductivity and temperature, the recycled water source was much more variable than the potable water source (Figure 4).

Diurnal temperature variation was again present in recycled water and, to a much lesser extent, in potable water. Similar temperature ranges were observed for recycled water (9˚C–24˚C) and potable water (18˚C–21˚Celsius) as in the SMF2 trials.

In contrast to conductivity and temperature data, fluorescence was always able to discern between the recycled and potable water sources. The calculated fluorescence ratio of 300/390 nm typically gave a two-times distinction between recycled and potable water (Figure 5). Recurring power failures to the SMF2 fluorimeter monitoring recycled water began occurring approximately 12 days into the study and were unable to be completely resolved before the study came to an end (Figure 5). Though fluorescence is temperaturedependent and has been identified as an important matrix effect to consider in fluorescence water quality monitoring (Hudson et al., 2007; Spencer et al., 2007; Henderson et al., 2009), the data shows the effect on sensitivity is likely to be minimal when daily variation is taken into account.

In-situ Trial 2: SMF4 Fluorimeter The conductivity of recycled water displayed much less variability than during trials with the SMF2 fluorimeter. It was typically observed between 980 and 1050 μS.cm-1, although just as during the SMF2 trials it decreased noticeably on a number of occasions. Potable water displayed

100 SEPTEMBER 2011 water

refereed paper

Fluorescence data from the SMF4 fluorimeter was much more convergent to the promising results previously obtained from bench-scale fluorescence analysis. Recycled water ranged from 1500 to 2300 afu, whereas potable water ranged from 390 to 600 afu, which gave a typical four to five times distinction between recycled and potable water (Figure 7). Fluorescence data within this study further accentuate the promise of fluorescence spectroscopy for detection of cross-connections between recycled and potable water systems. As optical technology continues to advance, the future could see cheap, reliable, fast, portable and sensitive fluorescence cross-connection detection systems become available.

Conclusions Two portable fluorimeters have been assessed for their ability to discern between recycled and potable water at an Australian water recycling plant. The results of this study highlight the advancement in portable fluorescence technology for water quality analysis, particularly within the context of crossconnection detection. Previous studies from weekly grab samples have calculated fluorescence to detect down to 45% intrusion of recycled water into potable water. This could be greatly improved by increasing the dataset and, hence, acquiring a more reliable

baseline for recycled and potable water fluorescence. In-situ monitoring of data such as within this study is an example of how this can be made possible. Fluorescence intensities at Peak T1 (λex/ =300/350 nm) were previously shown em to be able to distinguish recycled water samples from potable water samples with a high degree of sensitivity and reliability. Monitoring the fluorescence at peak T1 was found to be the most appropriate parameter for this distinction, where the intensities were determined to be typically 10 times that of potable water. This study has shown that by monitoring at similar excitation and emission wavelengths with a portable fluorimeter (λex/em=280/360 nm), recycled water is typically able to be distinguished from potable water by a factor of four to five. Accordingly, fluorescence spectroscopy is a promising technique for highly sensitive detection of cross-connections between recycled water and potable water distribution systems. As portable fluorescence technology continues to improve, the instrumentation is expected to evolve to provide highly sensitive portable capabilities.

Acknowledgements This research was supported under the Australian Research Council’s Linkage Projects funding scheme (Project Number LP0776347). The authors would like to thank our industry funding partners Allconnex Water, City West Water, Melbourne Water Corporation, South East Water, Sydney Olympic Park Authority, Sydney Water Corporation, Water Corporation and Yarra Valley Water. The authors would particularly like to thank Castor Rajanayagam, Greg Kennedy, David Elliot and Vicky Whiffin.

technical features


refereed paper

recycling PIPE JOINING SOLUTIONS

The Authors Adam Hambly (email: a.hambly@student.unsw. edu.au) is a post-graduate researcher at the Water Research Centre, University of New South Wales, and is currently finalising his thesis on “Fluorescence as a portable tool for crossconnection detection”. Rita Henderson, Professor Richard Stuetz and Stuart Khan are all with the Water Research Centre, University of New South Wales. Andy Baker is at the Connected Waters Initiative, Water Research Laboratory, University of New South Wales.

References

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ABC News, 2009: Recycled water mix-up leaves foul taste. Retrieved 12/01/2011 from http://www.abc.net.au/news/stories/2009/12/06/2763155.htm. Baker A, 2002: Fluorescence excitation-emission matrix characterisation of river waters impacted by a tissue-mill effluent. Environmental Science and Technology 36(7), pp 1377–1382. Baker A, Inverarity R, Charlton M & Richmond S, 2003: Detecting river pollution using fluorescence spectrophotometry: case studies from the Ouseburn, NE England. Environmental Pollution 124(1), pp 57–70. Bieroza M, Baker A & Bridgeman J, 2010: Fluorescence spectroscopy as a tool for determination of organic matter removal efficiency at water treatment works. Drinking Water Engineering Science 3, pp 63–70. de Rooy E & Engelbrecht E, 2003: Experience with residential recycling at Rouse Hill. Water Recycling Australia 2nd National Conference, Brisbane, 1–2 September 2003, Brisbane, Australia, Australian Water Association. Hambly AC, Henderson RK, Baker A, Stuetz RM & Khan SJ, 2010a: Fluorescence monitoring for cross-connection detection in water reuse systems: Australian case studies. Water Science and Technology 61(1), pp 155–162. Hambly AC, Henderson RK, Storey MV, Baker A, Stuetz RM & Khan SJ, 2010b: Fluorescence monitoring at a recycled water treatment plant and associated dual distribution system – implications for cross-connection detection. Water Research 44, pp 5323–5333. Henderson RK, Baker A, Murphy KR, Hambly A, Stuetz RM & Khan SJ, 2009: Fluorescence as a potential monitoring tool for recycled water systems: A review. Water Research 43(4), pp 863–881. Hudson NJ, Baker ADW, Brunsdon C, Reynolds D, Carliell-Marquet C & Browning S, 2008: Fluorescence spectrometry as a surrogate for the BOD5 test in water quality assessment: an example from South West England. Science of the Total Environment 391, pp 149–158. Hudson NJ, Baker A & Reynolds D, 2007: Fluorescence analysis of dissolved organic matter in natural, waste and polluted waters – a review. River Research and Applications 23, pp 631–649. Reynolds DM & Ahmad SR, 1997: Rapid and direct determination of wastewater BOD values using a fluorescence technique. Water Research 31(8), pp 2012–2018. Spencer RGM, Bolton L & Baker A, 2007: Freeze/thaw and pH effects on freshwater dissolved organic matter fluorescence and absorbance properties from a number of UK locations. Water Research 41(13), pp 2941–2950. Storey MV, Deere D, Davison A, Tam T & Lovell AJ, 2007: Risk management and cross-connection detection of a dual reticulation system. 3rd Australian Water Association Water Reuse and Recycling Conference (REUSE07), Sydney, Australia, UNSW Publishing and Printing Services.

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Storey MV, van der Gaag B & Burns BP, 2010: Advances in on-line drinking water quality monitoring and early warning systems. Water Research 45, pp 741–747. Sydney Water 2004: Media Release – Sydney Water working closely with Rouse Hill residents. Retrieved 11/03, 2009, from http://www.sydneywater.com.au/ WhoWeAre/MediaCentre/MediaView.cfm?ID=240. Sydney Water 2005: Media Release – Recycled water cross-connection at Newington. Retrieved 11/03, 2009, from http://www.sydneywater.com.au/ WhoWeAre/MediaCentre/MediaView.cfm?ID=295.

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asset management

WATER INFRASTRUCTURE Benefits of asset management-centred organisations Z Slavnic Abstract

Asset Management

Asset Management provides clear benefits to organisations that manage water infrastructure assets. However, many challenges still remain. From the author’s perspective, the most challenging appears to be integrated decision making, a crucial aspect of comprehensive asset management. This paper will examine organisational structure and decision-making process from the asset management perspective.

Asset Management, a tool used to manage infrastructure assets (for example, systems of transportation, energy and telecommunication networks, etc, as well as water and sewer networks, including pumping stations and treatment plants), gained momentum in the last decade or so, mainly due to:

Introduction Traditionally, water infrastructure in Australia is managed by government organisations. Irrespective of their size, they are conveniently organised into functional departments such as Projects, Operations and/or Maintenance, Finance, Support Services, and so on. However, in functionally centred organisations decision making is inevitably far from seamless. This is further exacerbated by vertical management hierarchy within each department. Departmentalisation, therefore, introduces a number of issues such as poor communication, poor inter-operability, conflicting objectives, etc. In such an operating environment, there is a risk of losing sight of the big picture, which Asset Management endeavours to portray. This article is an attempt to address this issue and suggest organisational changes to bring it in line with an essential ingredient of Asset Management – integrated decision making.

• Economic growth hinging on reliable infrastructure; • Regulatory requirements to justify asset owners’ expenditure (both Capex and Opex); • Heightened customer expectations and increased public scrutiny of corporate governance (as reflected by the recently released ISO 26000, Guidance on Corporate Social Responsibility). In simple terms, Asset Management involves looking after assets from cradle to grave. It is an iterative process of planning, asset creation or acquisition (design and construction), operation and maintenance, and asset disposal with the aim to provide for community needs on a long-term basis at the lowest costs. One of the key principles of Asset Management is that it should meet the needs of the present without compromising the needs of future generations, a UN definition of sustainable development. Figure 1, therefore, puts Asset Management in that perspective.

S E R V I C E P R O V I D E R S

Figure 1. Asset Management – the big picture.

102 SEPTEMBER 2011 water

Another key principle of Asset Management is that no decision should be made without giving due consideration to its impact throughout the life cycle of an asset. It is this principle that is frequently disregarded, and one of the reasons is organisational structure of water utilities.

Functionally Centred Organisations Most businesses these days are conventionally organised into functional departments, and water utilities are not an exception. Typically, they comprise a number of departments (Figure 2), such as: • Projects or Contracts: Responsible for planning, design and delivery of new water infrastructure assets. At large water utilities it is not uncommon for each of these to be a separate department. • Operations and Maintenance (O&M): In charge of O&M of assets. Frequently, O&M is split into two departments, one solely responsible for Operations and the other for Maintenance. • Finance: Responsible for both capital and operating expenditure. • Shared or Support Services: This may include Human Resources (HR), Information Technology (IT), Quality Assurance (QA) and Health, Safety

MANAGING DIRECTOR

P R O J E C T S

O P E R A T I O N S

M A I N T E N A N C E

F I N A N C E

HR, IT, QA, HSE, etc.

C U S T O M E R S

Figure 2. A functionally centred organisation.

technical features


asset management MANAGEMENT OR LEADERSHIP TEAM S E R V I C E P R O V I D E R S

A S S E T M A N A G E R

C U S T O M E R S

S E R V I C E P R O V I D E R S

A S S E T

C U S T O M E R S

M A N A G E R

S E R V I C E P R O V I D E R S

A S S E T M A N A G E R

C U S T O M E R S

SUPPORT SERVICES (HR, QA, HS&E, IT, Legal, etc)

Figure 3: An Asset Management-centred organisation. and environment (HS&E). Needless to say, each may be a department in its own right, and this is often the case. There is a vertical management hierarchy within each department. This hierarchy is necessary for coordination of all functional activities, management of information and, above all, to provide interface with other departments in the organisation. The better the coordination and interface management, the more efficient is the use of the organisation’s resources. However, associated with this organisational structure are a number of inherent issues, the main ones being: • Poor communication and information sharing; • Conflicting objectives; • Silo mentality in decision making; and • Inadequate interface management, hence inefficient resource utilisation. When each department has its own agenda, it is difficult to find a balance and get everyone pulling in the same direction, a task left to the managing director to deal with. These problems are evident in practice and probably the most exemplary one is when it comes to tender assessment – namely, a tenderer with the lowest cost is typically awarded the contract. This clearly demonstrates a lack of integrated decision making, as only capital costs are considered. However, the practice teaches us that the lowest priced tender is not necessarily the least expensive overall, as throughout the life cycle of an asset

it is the O&M costs that count. This is true for a simple reason – O&M costs are incurred over a long period, over several decades, depending on the type of asset. Another example that is probably not uncommon is when the decision is made to defer maintenance in order to save money, without giving due consideration to the impacts this has on the useful life of an asset, which is obviously shortened. The ultimate result of a decision like that is twofold: an accelerated need for major repairs and incurring capital costs for asset replacement earlier than originally planned. In order to ensure the lowest costs or best value for money, we have to take into account the costs associated with each of the phases of Asset Management, and not only of the asset acquisition (ie, design and construction). That is, we have to consider the life cycle cost. However, this is difficult to ensure if one department makes a decision on the capital expenditure and the other (or even two) are in charge of the O&M expenditure.

Asset Management-Oriented Organisations Fully embracing Asset Management principles demands integrated decision making and requires life cycle costing, so let us examine how this may be accomplished. If we think of sewage catchments, each catchment area comprises assets to collect (sewer network) and convey sewage (pumping stations and pipelines) and treat it at sewage treatment plants. All these are different types of assets but are clearly defined by their catchment areas. Therefore,

responsibility for managing all assets in a particular catchment area should rest with one person only, eg, the asset manager. In order to ensure integrated decision making and long-term benefits, the asset manager needs to be responsible for all expenditure associated with the assets under her/his management. Therefore, the asset manager needs to be responsible for both capital and operating expenditure. Figure 3 shows the organisational structure centred on the principles of Asset Management. There is no departmentalisation, as every asset manager is in charge of all the business associated with the assets she/he manages. Each asset manager clearly serves different customers, and may deal with different external service providers, eg suppliers, consultants, contractors, etc. Each is supported by the organisation’s internal services providers, eg HR, HS&E, Legal, etc. The management or leadership team is there to ensure the asset managers get the needed support, to align the organisation’s business with the objectives of governing bodies and to represent the organisation when dealing with other stakeholders. Developing this model requires a different mindset from the one prevalent today in that it requires long-term thinking; but that is not necessarily in the hands of water utilities alone. It needs to be recognised that, frequently, government regulatory or governing agencies themselves are, due to their focus on short-term benefits, an obstacle to long-term planning by water utilities.

Conclusion Adopting the Asset Managementcentred model requires full commitment to, and embracing an essential ingredient of, Asset Management – integrated decision making. This approach removes defocusing issues associated with functionally structured organisations, and empowers asset managers for both capital and operating budgets. It should, therefore, result in enhancing water utilities’ performance. Ultimately, it should ensure benefits to communities and society as a whole on a long-term basis.

The Author Dr Zoran Slavnic, PhD, MBT, MEng, BEng, FIEAust (email: zslavnic@ashghal.gov.qa), has 30 years’ experience in the water industry and currently works as Senior Advisor for Ashghal, Public Works Authority, Doha, Qatar. He is a member of the Committee for National Wastewater Strategy.

water

SEPTEMBER 2011 103


water business

NEED TO MODEL URBAN WATER USE? ASK BESS

Traditionally, urban water service network models (incorporating potable supply, sewer and stormwater systems) have focused on a single spatial scale like a headworks, subdivision or allotment. While such a focus has naturally arisen from the constraints of computational complexity and the need to work within the boundaries of management authorities, the new paradigm needs tools capable of exploring linkages not only between scales, but also between water service systems.

By Dr Mark Thyer, Senior Lecturer, School of Civil, Environmental and Mining Engineering, University of Adelaide, and Dr Matthew Hardy, Senior Environmental Engineer, BMT WBM Pty Ltd. As the Productivity Commission urges reform on a highly stressed urban water sector amidst growing pressure on water storages, Integrated Urban Water Management (IUWM) has never seemed more of an imperative. The “millennium” drought saw many urban water supply systems beset by historically low rainfall and inflows which forced unprecedented levels of water restrictions over recent years. Many Australian water authorities struggled to satisfy burgeoning demand.

As water authorities and developers increasingly embrace the IUWM design paradigm, there is growing recognition that IUWM designs must be both effective and efficient. This means accepting that such traditional models of the urban water system will no longer be sufficient.

The IUWM design paradigm, with its accent on household and cluster scale water management solutions, is becoming widely embraced, because it provides a viable alternative to largescale energy-intensive solutions for enhancing water supply security. IUWM imparts ‘water sensitivity’ to urban design while effectively integrating the physical and social sciences. It embraces a gamut of solutions, from awareness-raising to implementation of domestic water restrictions.

Instead there is an urgent need for urban water service network models to incorporate a greater understanding of urban water flows at spatial and temporal scales significantly smaller than those traditionally adopted for such design work. These models require water use/ demand inputs that incorporate the dynamics of water use at shorter temporal and spatial scales.

Above all, it allows evaluation of the impact of demand management incentives – adoption of water-efficient appliances, the installation of rainwater tanks and/or greywater reuse – on the design and operation of urban water systems from the household (allotment), to the cluster (subdivision), to the regional (city-wide) scale. Understanding that urban watercycle services meet at a range of scales, starting with a single allotment, is at the heart of IUWM. These meeting points facilitate examination of resource flows and allow for creation of internal loops and interactions to maximise resource efficiency and minimise system inputs and outputs.

Yet while research on water use/ demand modelling has been going on since the 1960s, there are still very few models specifically for household water use at short temporal scales. Instead, most models developed at the individual household scale simulate total household demand at longer time scales, such as bi-monthly, quarterly or annual. These models have typically been either linear or non-linear regression-based. By contrast most models dealing with shorter temporal scales, e.g. hourly or daily, are developed at larger spatial scales, such as an entire city. Evaluating the impacts of IUWM systems requires the ability to capture variations in water use across a range of spatial and temporal scales. Since such IUWM design measures are often implemented at the household scale,

knowledge of the dynamics of each water end use at the household scale at short time steps (sub-daily or daily) provide a valuable tool to assess the effectiveness of these incentives. Knowledge of the dynamics of household water use inevitably incorporates the human behavioural element.

The Human Element By working to reduce reliance on mains water supplies and deliver better environmental outcomes, IUWM emphasises household- and clusterscale water management solutions. It does so in part by allowing exploration of design scenarios which substitute tank water or greywater for household water uses such as toilet, shower, washing machine or outdoor use. Since these are typically implemented at the household scale, modellers need to understand the dynamics of each water end use. How many showers would the members of a given household or street have in any one week; how long would these showers last; and how much water would they typically consume? How many times would these householders flush the toilet in an hour or a day, and how much water would their washing machines and other water-using appliances consume? How does the water use change as people in the house or street adopt water-efficient appliances, or if architects, builders and developers installed more rainwater or greywater tanks and moved us away from the mains? These are the sorts of questions urban planners, managers and designers in the urban water sector grapple with every day. The Behavioural End-use Stochastic Simulator (BESS) (Thyer et al., 2011), developed by Thyer and colleagues in work funded by eWater CRC, takes a step towards filling the current gap by allowing users to simulate the way human behaviour impacts on household water use. It does so by stochastically simulating individual end uses at sub-daily time steps.

WaterGEMS® and SewerGEMS HYDRAULIC ANALYSIS SOFTWARE TO HELP MAKE WATER SYSTEMS MORE EFFICIENT WaterGEMS and SewerGEMS come equipped with everything engineers need in a flexible multi-platform environment, from automated fire flow and water quality simulations, to criticality and energy cost analysis, to automated design, bottleneck detection, and water loss analysis. These applications are part of Bentley’s integrated water solution which addresses the needs of owner-operators and engineers who contribute to the infrastructure lifecycle. For more information, see the inside front cover of the September issue of Water Journal, visit www.bentley.com/AWA, or e-mail sales.haestad@bentley.com.

104 SEPTEMBER 2011 water

water business


new products & services Now incorporated into eWater’s Urban Developer software product, this represents the first time a stochastic end-use model has been integrated with an urban water service network model. This enables users to model the impact of substituting mains water for alternative sources like rainwater tanks or greywater reuse for individual household end uses (washing machine, toilet, gardening, etc). BESS is made up of two components. The indoor component probabilistically simulates differences in household size, uptake rates of water-efficient appliances and diurnal variation in end-uses, with the model matching observed statistics from end-use data. The outdoor component probabilistically simulates the behavioural response of daily outdoor water use to rainfall and temperature. Evaluations using long-term multi-house outdoor water use data have shown BESS offers significant improvement in simulating observed variability (underestimation reduced from 56 per cent to eight per cent) compared with existing approaches (Micevski et al., 2011). To generate sub-daily outdoor water use values in BESS the daily values generated are disaggregated to sub-daily values by transforming the typical diurnal variation factor time series into a cumulative time series, expressing the cumulative percentage of daily outdoor water use at each minute of the day. The probabilistic behavioural approach with its underlying premise that water use is governed by people’s behavioural response to recent weather conditions, including both rainfall and temperature, reliably reproduces observed statistics and clearly outperforms traditional modelling approaches for simulating household outdoor water use. Furthermore, as the outdoor water use is higher and more variable at the end of hot, dry periods, when the storage in the rainwater tank is likely to be lower, this is likely to have a significant impact on mains water savings estimates from rainwater tanks. Research evaluating this impact is currently being undertaken. Although these results for the probabilistic outdoor component of BESS are promising, further work is needed to generalise its use in a design and operational context – this precludes its use in the initial release of Urban Developer. It is anticipated future releases of Urban Developer will incorporate a generalised version of the probabilistic outdoor water use component. Urban water use is changing, as prices change and people are becoming more “water-wise”. Smart metering and other detailed water use monitoring projects are continually improving our understanding of urban water use. The benefit of incorporating BESS into eWater’s Urban Developer software product is that it can be adapted in the future to take advantage of information from smart metering. The ability to take advantage of smart metering information in the design and operation of IUWM systems is aimed to motivate the development of a greater understanding of household water use, in particular, outdoor water use. Being able to reliably predict domestic outdoor water use enhances three different aspects of urban water resource management and design. For one thing, knowing the volume of outdoor water use is vital for assessments of the impact of water restrictions during times of drought – often the policy option of choice for decision-makers. Secondly, water infrastructure, such as pipes, pumping stations, transfer reservoirs and water treatment plants are typically sized to handle the peak day demand, which tends generally to be driven by outdoor water

use. Thirdly, outdoor water use is usually the first supplied by alternative sources (rain/greywater systems) to reduce mains water demand.

Summary BESS’s incorporation into eWater’s Urban Developer delivers a major breakthrough by allowing users to simulate the way human behaviour impacts household water use and compare options for integrated water management from lot-to-cluster scale. The next generation software tool incorporates all three urban water cycle services – potable, waste and stormwater – within a single framework. It can simulate demand and supply interactions at sub-daily time scales, and can deal with catchment rainfall-runoff responses at a range of scales. “For the first time, users can make decisions based on all elements of the urban water cycle (stormwater, wastewater and potable water) taking consideration of a wide range of potential management intervention factors including reuse, alternative sources of supply, water-efficient appliances, etc,” says Tony McAlister, Managing Director, BMT WBM Pty Ltd. It allows users to simulate and evaluate a wide range of potential integrated urban water management strategies which we know are so important to creating the sustainable cities of the future.”

References Micevski T, Thyer M & Kuczera G, 2011: A Behavioural Approach for Household Outdoor Water Use Modelling, Water Resources Research, submitted. Thyer M, Micevski T, Kuczera G & Coombes PJ, 2011: A Behavioural Approach to Stochastic End-use Modelling, Ozwater’11 Conference, Adelaide, South Australia.

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SEPTEMBER 2011 105


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Decentralised wastewater treatment systems, treating greywater or blackwater, are an integral part of sewage management in Australia. In addition, decentralised wastewater treatment systems have emerged as a popular option for water reuse, due to demand on limited potable water supply in both reticulated and non-reticulated areas. Therefore, wastewater treatment and reuse is being embraced both as a necessary and sustainable wastewater management option. Our services include: • Aerated wastewater treatment system (AWTS) accreditation monitoring; • Annual accreditation testing across NSW; • EPA AWTS recertification; • Assessment of environmental impact using buffer distances; • Pilot plant development and testing of new technology and systems; • Assessment of long-term system performance;

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• Challenge testing with MS2 bacteriophage or other organisms including clostridia, E. coli and Cryptosporidium; • Assessment of disinfection types; • Dye or conservative salt tracers to determine effluent breakthrough in a system or land application area; • Design and implementation of monitoring programs; • Analytical data interpretation; • Risk assessment; • Regulator liaison and compliancereporting to regulators and councils. ALS WSG has successfully provided these services over the last 10 years and is well recognised by regulators and certifying bodies. ALS WSG operates consulting services certified to ISO 9001 and is JAS-ANZ certified. ALS Environmental is NATA accredited for sampling and laboratory analysis to ISO 17025. For further information email: danielle. baker@alsglobal.com or patty.chier@ alsglobal.com or call 1300 326 947.

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106 SEPTEMBER 2011 water

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new products & services piping

THE INVENT iDISC® FINE BUBBLE DIFFUSER INVENT designs, manufactures and globally implements innovative machines and processes for the treatment of water and wastewater. The company has now launched the iDISC® fine bubble diffuser as the latest product addition to its aeration and mixing range.

Disc Surface Area:

0.044m2

Number of Slits:

3850

Acetyl Sliding Ring

Check Valve Every iDISC diffuser has a non-return membrane check valve installed onto the airincoming orifice at the base plate of the main body. The design of this key component assures even air flow distribution into the main body and controlled pressure loss over the whole aeration system. Also, it prevents the liquid back flow when air is stopped.

The iDISC® membrane is manufactured from low volatile EPDM perforated with slits. Fine air bubbles with diameters ranging between 1 to 3 mm are formed when the air passes through the slits of the membrane. The slits open when compressed air is supplied and closes when the air supply is stopped. The membrane is mounted on a removable support plate. The air distribution ports in this support plate are positioned at the periphery so as to avoid direct air impact to the membrane and to enhance air distribution over the complete surface. The membrane and the support plate are fixed by protection anti-wear and screw-on rings to the main body. Within the main body there is a critically sized orifice and an additional non-return valve. The orifice assures even air distribution between diffusers, while the non-return valve provides an additional level of protection against ingress of water into the air supply piping. The main body is secured onto standard 90OD and 3" pipe with a wedge piece. These special design features and manufacturing criteria result in a robust, reliable and longlasting aeration device.

Membrane Disc Material:

Low volatile EPDM

Air Flow rate:

1.5 to 6 Nm3/h/diff.

Membrane Diameter:

237mm

Support Plate The support plate has a robust shape that avoids deformation through the whole lifetime. This base plate is manufactured in PP with a high content of fibreglass to withstand high temperatures. The air inlet ports of the base plate are at the periphery, achieving a smooth and uniform air distribution below the membrane.

solutions

Inventor of grooved-end technology

NEW labor-saving products such as the patented QuickVic coupling (www. victaulic.com/quickvic)

Designed for piping systems up to 60"/1500mm (www.victaulic.com/ advancedgroovesystem.htm)

Vertically integrated coupling, fitting and valve manufacturer in the market

Nearly 500 factory-direct sales engineers globally for support and field training

3:1 safety factor

Full range of products for the water market

Estimating, pre-planning and project management, jobsite training, software solutions, and construction drawings.

®

The iDisc.

Diffuser Body Construction material of the iDISC® diffuser is polypropylene + glass fibre, allowing design temperatures of 100ºC. Each component is designed and manufactured for heavy-duty applications. The material is a result of specific studies and the special blend has a density of 1.13 kg/dm3 that dramatically decreases the buoyancy effect.

system

Don’t put your project at risk. Choose Victaulic.

Dynamic Wet Pressure: 2 to 4 kPa

An anti-friction ring of poly acetyl, which is a self-lubricating material, is interposed between the membrane and the screw-on ring. The purpose of this sliding ring is to diminish the friction wear and avoid the risk of the membrane bonding with the screw-on ring. It also allows easy replacement of the membrane after years of operation.

To learn more about our products visit www.victaulic.com/content/ watersystemstechnology.htm

Piping System Every iDISC® diffuser is fixed mechanically to the air pipe with a saddle piece and wedge piece which allows an easy disassembly and reinstallation of each diffuser individually. No glue, screws or other type of fasteners are used for the installation. The piping system comes standard as a “kit”. All components required for installation are included in the delivery.

Condensate Drainage The iDISC® aeration system is designed as a closed loop system. The outer end pipe collects the condensate water from every air distribution pipe. The venturi coupling self-drains the condensate water accumulating in the piping system above the water surface of the basin.

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SEPTEMBER 2011 107


new products & services plant, effluent quality may struggle to meet environmental licence conditions, and in some instances community or government pressures may be demanding higher qualities of effluent than what the treatment process is capable of producing.

System Performance Guarantee Invent owns and operates one of the largest purpose-built oxygen transfer test tanks in the world. Located at the production headquarters in Erlangen, Germany, the test facility is fully instrumented, providing high accuracy dissolved oxygen and air flow monitoring. All instrumentation readings are controlled and data logged back at a central control centre. Invent guarantees all aeration system designs to globally recognised ATV and ASCE standards.

Aeration Design Services

At EcoCatalysts we’re the experts at reducing your operation & maintenance costs. Com at AW e & See Us A Confe NQ Regio nal ren Boo ce 2011 th 7

EcoCatalysts is bringing about a fundamental transformation in the advanced treatment of our water resources and bio-remediation.

Invent offers a no obligation design service to assist in the sizing of aeration basins. This includes calculation of AOR and SOTR, tank dimensioning, possible layout alternatives, supply air requirements and blower sizing recommendations. Invent is also perfectly positioned to advise on a (Alpha) factors and fouling allowances for both municipal and industrial water treatment. For more information email: info@inventpacific.com or phone 02 6365 0702.

LOW-COST SOLUTION FOR AGEING SEWAGE TREATMENT PLANTS Ageing sewage treatment plants can present both a treatment and environmental headache for many municipal authorities around Australia, particularly in regional and remote communities. Actual flows may exceed the design capacity of the treatment

Constructed wetlands are an excellent low-cost solution that can be easily added on the back end of ageing STPs to help provide much needed improvements. When designed properly, wetlands can seamlessly integrate into an overall treatment process without disruption to the ongoing functionality of the STP. They are a significantly lower cost option compared to building a new STP and can be implemented quickly to address immediate issues, delaying large future infrastructure investments. Being a non-mechanical solution, they use no electricity, have a low carbon footprint, are resilient to flooding, and require little maintenance. The effluent produced from a well-designed wetland is also less variable and has lower nutrients than many modern BNR plants. The design philosophy of constructed wetlands has changed over the last 20–30 years. When constructed wetlands were first trialled in Australia in the ’80s and ’90s, the results were by no means impressive. The performance was inconsistent from one site to another and the design approach varied. The early wetlands in Australia in some respects were designed “blindly” as the mechanisms of treatment were not widely understood, and in some cases the wetlands made the effluent quality worse. Unfortunately, many wastewater professionals in the industry have based their view of constructed wetlands on these failures, without realising that the technology has come a long way over the last couple of decades.

Our Product Range Covers

Wastewater Odour Control u Bio-Remediation u

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Call: 1800 207 009 Email: info@ecocatalysts.com.au Web: www.ecocatalysts.com.au

The trickling filter at South Lismore STP is coupled with a constructed wetland.

108 SEPTEMBER 2011 water

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new products & services Today, there is a much greater depth of knowledge of the treatment mechanisms at work in wetlands, which has allowed the development of comprehensive design models. Constructed wetlands can be built into the treatment train of STPs to deliver effluent quality of a more consistent quality than traditional STPs. They also produce higher and more stable nutrient reduction performance than what could be achieved by most chemically dosed BNR plants that don’t use constructed wetlands.

Some of the main differences in which constructed wetlands have changed over the years are in the way they are designed, built and maintained. Twenty years ago, it was thought that the majority of nutrient removal was achieved through absorption into the biomass. As a result, the maintenance strategy was to periodically harvest or burn the wetland vegetation. It is now known that only about 7–9% of nutrients are removed by being incorporated into the wetland biomass and that the majority of nutrient removal is actually achieved through either microbial processes for nitrogen and adsorption pathways for phosphates. Essentially the constructed wetland ecology provides a high surface area for microbes to attach to and perform treatment (through roots, stems, leaves, organic detritus etc). This understanding has led to one of the major changes in wetland design strategy, which is to increase the density of vegetation as much as possible, with no open water to maximise microbial surface area for treatment. When these design principles are followed (obviously along with other scientific and engineering design elements), constructed wetlands deliver reliable and consistent results. An excellent example of where constructed wetlands have been used to remediate ageing wastewater infrastructure is the 22,000EP South Lismore Sewage Treatment Plant. This is one of three owned and managed by Lismore City Council and comprises primary-secondary trickling filters, waste stabilisation ponds and constructed wetlands. The trickling filter is about 80 years old, being one of Australia’s oldest systems. Despite the age of the treatment infrastructure, the performance of the STP is amazingly among Australia’s best due to it being coupled with a highperforming constructed wetland.

Incorporating a wetland as part of the treatment train has meant that the nutrient concentrations in the effluent are consistently much lower than the required licence limits; without the wetland, the old trickling filter would have struggled to meet the license quality objectives. Although the South Lismore STP wetland performs so well, it was not developed in an optimum configuration. It is actually undersized for the flow and doesn’t incorporate a comprehensive flow control system that would be employed in greenfield constructed wetlands. The wetland was retrofitted into one of five pre-existing open ponds that were previously established on site, and consequently has been built with a number of site restrictions. Knowing this background makes the results even more impressive. When engineered wetland systems are installed to incorporate full design attributes, the results can be even more exceptional, achieving average TN’s<1mg/L and TP reductions of up to 90%. The table below gives a summary of effluent quality data from 2008 to 2011, taken at the outlet of the South Lismore Treatment Plant constructed wetland. Parameter TSS – mg/L

Median

90%ile

0.7

1.9

BOD – mg/L

0.9

2.5

TP – mg/L

0.5

0.8

TN – mg/L

2.4

5.8

To find out more please contact Ian Kikkert from the Water and Carbon Group on 0437 000 628 or email: i.kikkert@ waterandcarbon.com.au

BARWON WATER USES WATERGEMS TO IMPROVE PRODUCTIVITY Barwon Water, the largest regional urban water corporation in Victoria, provides world-class water, sewerage and recycled water services to more than 275,000 people across 8,100 square kilometres. Its AUD 1.138 billion asset base includes 5,781 kilometres of pipes, 10 major reservoirs, 10 water treatment plants, and nine water reclamation plants. The utility deployed Bentley’s WaterGEMS water distribution modelling software, integrated with their geographic information system (GIS) to simulate shutdowns and measure the impact on system performance. A key performance indicator (KPI) for customer service is the number of customers affected by planned and unplanned supply interruptions. WaterGEMS helped Barwon Water identify

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SEPTEMBER 2011 109


new products & services critical mains defined as pipes that would interrupt service for a large number of customers should shutdowns occur. Prior to deploying WaterGEMS, identifying and quantifying every critical element in the utility’s water distribution system would have been too manually intensive and required a great deal of analysis.

Hydraulic Modelling for Criticality The use of hydraulic modelling capabilities has made it easier for the utility to “fail”

a pipe and assess its impact on the system. The criticality analysis tool in WaterGEMS allows users to automatically simulate the shutdown of each individual segment of the system and determine the impact on performance. How critical each pipe is to the system is automatically based on the number of customers that would be affected should the pipe fail. The criticality analysis results are then presented graphically in Barwon Water’s GIS system. This helps operations

and planning personnel to access the information and to more efficiently plan network improvements and optimise asset management decisions. Barwon Water’s system includes 30 network models. Pressure zones range from as few as 100 properties to more than 20,000. The report generated from WaterGEMS is based on the percentage of the zones’ water demand that is not meeting defined minimum pressure levels. (The analysis is run with three defined minimum pressure scenarios.) In the Oracle database, the percentage of demand affected is linked to the number of lots affected. A scoring number is utilised based on the number of affected customers. A weighting factor is allocated on each defined minimum pressure. This score is then used to classify the level of criticality.

Improved Productivity A critical pipe layer was created in Barwon Water’s GIS Oracle Spatial database, which the utility had successfully integrated with WaterGEMS. The use of GIS data via a direct connection to the Oracle Spatial database has made the model building process more efficient. Because the criticality analysis results are visualised in the GIS system, the

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110 SEPTEMBER 2011 water

AWA - May & September issues

water business


new products & services distribution of vital information to planning, operations, and management staff in Barwon Water has been accelerated. The efficient schematic process of critical mains identification, shown opposite, has enabled Barwon Water to save an estimated two years of work, which corresponds to a cost saving of about AU$200,000, while improving the accuracy of the results when compared to a manual, error-prone process.

Community Impact Another of Barwon Water’s objectives was to ensure that all water and sewerage systems and services are efficient and effective, and that they meet both legal and government requirements, as well as community expectations. This project enabled Barwon Water to optimise asset management decisions and more reliably meet customer service targets for planned/unplanned interruptions to supply, which will improve the overall quality of service to customers.

HUBER Strainpress®, which removes fine screenings and fibre from mixed sludge streams prior to anaerobic digestion, has already been widely used in the UK and Europe due to its efficiency and ability to reduce maintenance costs.

the commissioning of the plant, the population of the region has increased dramatically. To meet the population growth, the Water Corporation has upgraded the plant to its current capacity of 120 megalitres per day.

Ovivo supplied a solutions equipment package to the Beenyup sewage treatment plant in a suburb of Perth, Western Australia. It included HUBER fine screening equipment and HUBER RoSF4 advanced grit washing technology.

The HUBER Strainpresses® enable the plant’s anaerobic digestion processes to run more efficiently. Each Strainpress® is sized for 60m3 per hour and each has its own proprietary control system, enabling the machine to self-regulate against varying feed solids.

The treatment plant, a comprehensive treatment plant that produces high quality effluent, receives and treats wastewater from the surrounding communities. Since

The Strainpress® units screen a mixture of primary and secondary sludge prior to anaerobic digestion.

HUBER STRAINPRESS®: PROTECTING ANAEROBIC DIGESTERS Ovivo Australia has introduced new sludge screen technology to the wastewater treatment market. The

Designer and manufacturer of high efficiency, low speed floating and fixed surface aerators from 3kW to 220 kW with an unmatched 5 year, unlimited hours guarantee. By-Jas offers flexible financing and delivery solutions including rental, purchase and fully maintained operating leases. Ring now for a current stock list. Other products in our range include settling tanks (12 designs), packaged sewage and water treatment plants, reuse filters and clarifiers to Class B and Class A standard. For more information, contact: By-Jas Engineering Pty Ltd PO BOX 424, HASTINGS VIC 3915 Tel: (03) 5979 1096 Fax: (03) 5979 1524 www.byjas.com.au

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SEPTEMBER 2011 111


new products & services

P ENS TO CK S

The Strainpresses® allow digestion to run more efficiently, which in turn significantly reduces maintenance costs and allows for increased gas production within the digestion. The machines have 5mm screenings sections, and a pre-coat forms on the screen resulting in the removal of very fine fibre from the sludge stream.

into the anaerobic digesters. This equates to over 7,000 tonnes per year. Depending on the digester design, Strainpresses® will assist greatly in protecting floating gas cover, gas mixing systems, recirculation pumps and heat exchange equipment.

This installation was the fourth in Australia for Ovivo, others being at Christies Beach in Adelaide. The Strainpresses® were chosen for their efficiency and ability to protect the downstream plant equipment. The HUBER grit washers were selected due to their high efficiency and performance. Their performance exceeded all guarantees, resulting in significant reduction off offsite disposal costs.

Strainpress® is controlled automatically against varying feed solids. The motor power consumption is measured continuously and controls a pneumatic system, which regulates pressure within the Strainpress®. The system can be installed in closed pipes and the headloss through the Strainpress® is typically 0.4–0.6 bar. Even with fine screens installed at the head of the plant, HUBER Strainpress® will remove the fine fibre and screenings that pass through headworks.

Since commissioning, the Strainpress® plant has consistently removed 20 tonnes per week of screenings that would normally pass

For further information please contact Ovivo Australia on 02 9542 2366 or visit: www.huber-technology.com.au

AD VE RTIS E RS ’ IN D E X ABB Australia Acromet AIRVAC ALS Environmental

9 106

ITT WWW

27 IBC

James Cumming & Sons

72

KASA Redberg

29

43

KCES

101

Australian Vinyls

23

Merck

24

Merriman Controls

31

Mia Renewal Alliance

22

AWMA Water Control Solutions

5

AWMA Water Control Solutions

112

Bentley Systems, Inc

IFC

Bentley Systems, Inc

104

Brown Brothers Engineers Australia

110

By-Jas Engineering

Odour Control Systems (Aust)

111

Pipes Wagga Wagga

105

Piping & Automation Systems

45

57

Plassons Australia

37

111

Plassons Australia

39

Calgon Carbon Corporation

11

Projex Group

Campbell Scientific Australia

36

Promains

13

Tenix

35

The Water & Carbon Group

47

Thiess

48

TRILITY

95

Trojan Technologies

53

COMDAIN Infrastructure

Quality ISO 9001

110

ITT RCW (Lowara)

Atlas Copco Compressors

BTG Australia

DESIGN MANUFACTURE I N S TA L L

15

7

CRS Industrial Water Treatment Systems

49

CST Wastewater

21

EcoCatalysts Franklin Electric (Australia)

108 OBC

106

Hach

30

Tyco Water

Hickory Group

17

Victaulic Australia/New Zealand

Hydro Innovations

34

WaterAUSTRALIA

77

Ph 1800 664 852

Invent Pacific

26

Water Infrastructure Group

28

www.awma.au.com

Iplex Pipelines Australia

52

Waterco

ITT Fluid Technology

25

Weidmuller

112 SEPTEMBER 2011 water

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Water Journal September 2011  

Water Journal September 2011