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Volume 40 No 1 FEBRUARY 2013
Journal of the Australian Water Association
From Ancient Roman Aqueducts to State-of-the-Art Desalination Plants ... Why We Need Innovation In Water â€“ see page 40
> Wastewater Management & Treatment > Small Water & Wastewater Systems > Direct Potable Reuse > Water Quality
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Contents regular features From the AWA President
Welcome To The Year Of Water Co-operation Lucia Cade
From the AWA Chief Executive
A Bright New Year – And A Fresh New Look And Feel Tom Mollenkopf
Crosscurrent 10 18
Industry News AWA Young Water Professionals The Power Of Passion Jo Greene
The Case For Urban Metabolism Steven Kenway, Francis Pamminger & Paul Lant
New Products and Services
MANAGING EDITOR – Anne Lawton Tel: 02 9467 8434 Email: firstname.lastname@example.org TECHNICAL EDITOR – Chris Davis Email: email@example.com
My Point of View
A Land Of Weak Politicians And Fat Wallets Christopher Gasson
32 94 100
CREATIVE DIRECTOR – Mike Wallace Email: firstname.lastname@example.org ADVERTISING SALES MANAGER – Kirsti Couper Tel: 02 9467 8408 (Mob) 0417 441 821 Email: email@example.com NATIONAL MANAGER – PUBLISHING – Wayne Castle Email: firstname.lastname@example.org CHIEF EXECUTIVE OFFICER – Tom Mollenkopf EXECUTIVE ASSISTANT – Despina Hasapis Email: email@example.com EDITORIAL BOARD Frank R Bishop (Chair); Dr Bruce Anderson, AECOM; Dr Terry Anderson, Consultant SEWL; Graham Bateman, CH2M HILL; Dr Andrew Bath, Water Corporation; Michael Chapman, GHD; Wilf Finn, Norton Rose Australia; Robert Ford, Central Highlands Water (rtd); Ted Gardner (rtd); Antony Gibson, Orica Watercare; Dr Lionel Ho, AWQC, SA Water; Dr Brian Labza, Dept Health WA; Dr Robbert van Oorschot, GHD; John Poon, CH2M Hill; David Power, BECA Consultants; Dr Ashok Sharma, CSIRO. PUBLISH DATES Water Journal is published eight times per year: February, April, May, June, August, September, November and December. Please email firstname.lastname@example.org for a copy of our 2013 Editorial Calendar. EDITORIAL SUBMISSIONS Acceptance of editorial submissions is at the discretion of the Editors and Editorial Board. • Technical Papers & Technical Features: Chris Davis, Technical Editor, email: email@example.com AND firstname.lastname@example.org
Inside the 1.2km underground intake tunnel of the Victorian Desalination Plant.
volume 40 no 1
special features Walking The Talk: Part 2
Securing Another Thousand Years Andrew Hodgkinson & Sejla Alimanovic
Time To Innovate – Or Die
How To Work Smarter, Not Harder Claire Dixon
Changing The Face Of Australian Infrastructure An Overview Of The AGIC Rating Scheme Tony Wragg
Ready For The Drought...
The Controversial Wonthaggi Desalination Plant
technical papers Cover The well-known ancient bridge-aqueduct, Pont du Gard in Provence, France, is a wonderful example of innovation in Roman engineering.
• General Feature Articles, Industry News, Opinion Pieces & Media Releases: Anne Lawton, Managing Editor, email: email@example.com eneral Feature Submission Guidelines G General Features should be 1,500–2,000 words and accompanied by relevant graphics, tables and images. For more details please email: firstname.lastname@example.org • Water Business & Product News: Kirsti Couper, Advertising Sales Manager, email: email@example.com
Gippsland Water Factory: Membranes At Work Solving A Sixty-Year Environmental Problem Andrew Hodgkinson
echnical Paper Submission Guidelines T Technical Papers should be 3,000–4,000 words long and accompanied by relevant graphics, tables and images. For more detailed submission guidelines please email: firstname.lastname@example.org
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 AWA. PUBLISHER Australian Water Association (AWA) Publishing, 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: email@example.com, Web: www.awa.asn.au COPYRIGHT Water Journal is subject to copyright and may not be reproduced in any format without the written permission of AWA. Email: firstname.lastname@example.org DISCLAIMER Australian Water Association assumes no responsibility for opinions or statements of fact expressed by contributors or advertisers.
February 2013 water
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Tenix has designed and built, and is now operating, Victoria’s largest standalone underground Water Recycling Facility - in Yarra Park, adjacent to the Melbourne Cricket Ground (MCG). The $22m scheme, funded by the Melbourne Cricket Club ($16 million) and the Victorian Government ($6 million), treats sewage from the local sewerage network to ‘Class A’ recycled water standards to irrigate the heritage-listed park and nearby Punt Road Oval, as well as for cleaning and toilet-flushing at the MCG. The plant is able to produce over 600 kilolitres of recycled water per day. As one of the first of its type in Victoria, the Tenix-designed recycling facility has been built underground, out of public view, without taking way from valuable surface land use or park amenity. Key Features The recycled water treatment process consists of screening and grit removal, biological treatment of the sewage and chemical addition for phosphate removal, filtration via membrane bioreactor (MBR) and ultrafiltration (UF) membrane systems, and disinfection via ultraviolet (UV) and chlorination. The underground plant has a trafficable roof, and architecturally designed entry and egress with a box lift and chemical unloading area. Associated infrastructure on the inlet side includes
the sewer connection, diversion structure/ chamber, a 13-metre by 4.8-metre (diameter) pumping station and a rising main. Other infrastructure includes the connections into the MCG under the concourse to a pre-existing storage tank, and to Punt Road storage as well as a pump station and sludge return gravity line downstream of the sewerage take-off. The MCC and their partners were keen to ensure that the design, construction and operation of the plant minimise any impact on the park, its users and other stakeholders including residents, regulatory authorities and members. The MCC also wished to retain the aesthetics of the existing parkland and maintain the availability of parking. Our Role Tenix’s in-house engineering team worked collaboratively with the MCC and their partners to ensure that all project requirements were met and also developed a number of technical and operational improvements to the original plant concept. Tenix provided the process, mechanical, civil, electrical, instrumentation and control design (including 3D modelling), and construction (including earthworks), commissioning, coding for plc/SCADA, and validation for Class A. For more information visit www.tenix.com
Sustainability The recycled water will be used for cleaning and toilet flushing at the MCG and will reduce its reliance on potable water by 50 per cent and remove it from the list of Melbourne’s top 100 water users.
Innovation Tenix introduced a number of technical and operational improvements to the original plant concept and employed innovative construction techniques to improve safety and minimise disruption to stakeholders and the environment.
From the President
Welcome to the Year of Water Co-operation Lucia Cade – AWA President
The United Nations has declared 2013 the International Year of Water Co-operation. In proclaiming this, the UN restated a number of its goals regarding the role of water: that access to safe water and sanitation is a human right; that water plays an essential role in eradicating poverty and hunger; that it is indispensable for human health and well-being; and that water is central to achieving the Millennium Development Goals. However, the UN remains concerned by the slow and uneven progress in achieving the goal of halving the proportion of the population without sustainable access to safe drinking water and basic sanitation, while global climate change and other challenges seriously affect water quantity and quality. In January the International Annual UN-Water Conference was held in Zaragoza, Spain, with the theme of preparing for the International Year of Water Co-operation – Making It Happen! In reading the key lessons learnt, it struck me that the same issues, lessons and solutions also apply in Australia. No matter where a country sits on what I call “the safe water evolution” path it’s the same things that drive success. In Australia we are clearly at the enviable end of the spectrum – and the co-operation frameworks discussed at this conference remain fundamental to how we continue to achieve the right balance in sharing our water resources and creating a long-term sustainable water balance to support our people, our economy and our environment. They include: • Political will As we have seen in the bi-partisan agreement on the Murray-Darling Basin Plan.
water February 2013
• Multi-stakeholder platforms Bringing together government, utilities, the private sector, technical experts and communities to generate implementable solutions. Building a shared vision remains an important precursor to effective cooperation and, hence, effective solutions. • Institutional arrangements that support and facilitate access to decision makers by those who will be affected by solutions. • Financing from multiple sources Looking beyond government sources to enhance the capacity of a society to invest in its resources. AWA is proud to promote co-operation in water in a variety of ways. On an international scale AWA, along with the Australian water industry, continues to support WaterAid in its activities. The 2013 fundraising season kicks off with the WaterAid Ball in Melbourne on 22 March. Operating at a different level of co-operation, many of our water corporations have twinning relationships with developing utilities overseas, while AWA’s own Fiona Mackenzie has for the past year been on secondment in Samoa with the Pacific Water & Wastes Association. Finally, on a completely different note, at the end of last year I welcomed to the AWA Board three new directors: Carmel Krogh, Mark Sullivan and Mal Shepherd. However, in fact we have four new members! The board will also include John Graham, Business Development Manager at Monadelphous and a past President of the Queensland Branch. John will be a great addition to the board, and has been very gracious regarding my poor form in not properly proofing my last column!
From the CEO
A Bright New Year – AND A Fresh New Look and Feel Tom Mollenkopf – AWA Chief Executive
One of my New Year resolutions (there were several, not all of which I need to share here!) is that I should not hide AWA’s light under a bushel. It seems to me that sometimes we are so busy doing that we fail to stop and share the depth and breadth of AWA’s opportunities and offerings. So I’d like to kick off the year with some shameless – but honest and important – promotion of what’s new and what’s happening at AWA.
IWA and AWWA, you now have access to the latest
To start, as you flip through this edition of Water Journal, I hope it is not only the assiduous readers who notice some subtle but important changes. As part of our work to continuously improve the AWA member offer, this first 2013 edition sees an enhanced look and layout. In addition, we are embarking on the first step of an electronic version of the journal.
are readily accessible via an extensive search feature.
Content, of course, remains paramount. Our Editorial Board will continue to ensure that you are presented with topical and thought provoking articles as well as quality peer-reviewed papers. To complement the selfless volunteers on the Board, I am pleased to announce that Chris Davis – someone who needs no introduction – is taking on a more formal role as Technical Editor of Water Journal. Another change is to our weekly E-News, which features a new look and revised content. Early indications are that this essential communication tool is hitting the spot, with the first “issue” reaching a new record hit rate with subscribers. Continuing with the publications theme, our new Online Bookshop provides a wide range of titles on all aspects of water, wastewater and related environmental fields. Through partnerships with
technical print and online publications. Significant discounts are offered to AWA members and delivery times on many publications have been dramatically cut through our local Print-on-Demand capability. There is a also a growing range of resources available free to members via the AWA Online Document Library. We are continuing to add papers from AWA Conferences, as well as Water Journal articles. These
2013 will again see a comprehensive program of AWA conferences, technical sessions, master classes and training opportunities. Ozwater, which will be held in Perth in May, has an international flavour with a strong line-up of Australian and overseas keynotes and a reach into south-east Asia in particular. There will also be a series of targeted specialist conferences during the year, including parallel Membranes & Desalination and Recycling Conferences (July, Brisbane), Leading Edge Strategic Asset Management (September, Sydney), and – about to kick off (March, Sydney) – our Efficiency, Education and Skills Conferences. On a personal note, after some six years at the helm of AWA, I have flagged my intention to stand down from the CEO role in July this year. I continue to enjoy the academic and organisational challenges immensely, but the next phase for me beckons. Meanwhile, there is much to look forward to in 2013 – I hope that you, like me, can see the opportunities that lie ahead.
February 2013 water
My Point of View
A LAND OF WEAK POLITICIANS AND FAT WALLETS Christopher Gasson – Publisher, Global Water Intelligence
As publisher of Global Water Intelligence, Christopher Gasson has been a leading international commentator on the water industry for the past decade. This is an edited extract from his speech given at the AWA National Water Leadership Summit in Canberra from 30 October –1 November 2012. I am supposed to be giving a global perspective on the Australian water sector. I suspect, however, that you don’t really want that. The truth is that if you asked most people outside Australia what they thought of what has happened here over the past five years they would give it to you straight. Australia is a land of weak politicians with fat wallets. When the drought came along the politicians spent whatever it took to save their skins, and ended up with a full set of the most expensive desalination and water reuse facilities in the world. Then it rained. One by one the desalination plants are being mothballed and the revolutionary water reuse plants are diverting their output into the sea. But let’s spend a bit of time looking at the alternatives. Everyone complains that desal plants are expensive – but where else could you get water during that drought? If there is a drought, building more dams and diversions isn’t going to help. Similarly a big city cannot survive on water reuse alone. There is only one source of additional freshwater resources that is truly droughtproof, and that is desalination. On the other hand, desalination’s strength is also its weakness. If you build something because it is the only thing that will protect you in the event
WATER FEBRUARY 2013
of an extreme drought, you shouldn’t complain if it is only used occasionally. It is like buying a life insurance policy and then complaining after a few years that you are not dead yet.
CHEAP AT THE PRICE The Melbourne desalination plant is an insurance policy that costs each resident of the city 36 cents per day. If that sounds expensive, think about what you are insuring against. It is not just the threat of forced evacuation of the city, the possibility of power brown-outs, the economic losses to businesses that are dependent on water. It also protects the livability of the city. The price includes the cost of building the facility 137kms outside the city to ensure Port Phillip Bay is not disfigured. The cables and pipelines servicing the plant are buried, and the facility itself has been designed to ensure that it does not impinge on the landscape. These things are expensive. But they are an important part of ‘brand Australia’. Livability is an essential element of your competitive advantage vis-à-vis Beijing or Bangalore. Other cities might be cheaper, but can they provide an environment that attracts the best global talent? And what about businesses? Over the past five years concerns about water risk have grown to become one of the most important corporate sustainability issues. This is being driven by the realisation that the effects of global warming are being felt first through the world’s water systems. The droughts and floods that Australia has experienced are part of a global phenomenon. As temperatures rise the water cycle is becoming more energetic, with more intensive
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My Point of View periods of evaporation and greater releases of energy in precipitation events. Investors have begun to realise that water risk is an under-appreciated threat to the profitability of the companies they invest in. Businesses are being asked to assess and disclose their water risks, and make efforts to reduce them. The Carbon Disclosure Project (CDP) has launched a water risk disclosure initiative backed by investors with more than $50 trillion under management. Ceres, a US investor group with a strong sustainability agenda, is also pushing companies to analyse their water risk. How are corporations going about this? It is an emerging science, but there seems to be a consensus that finding out where future demand and supply are most out of kilter is the key to identifying water risk. A number of NGOs such as the World Business Council for Sustainable Development, the World Resources Institute and the Water Footprint Network have been developing water risk maps that project water demand forward and overlay that with freshwater availability to show where in in the world there is greatest risk of absolute scarcity. And you know what? Over Melbourne there is a big red mark showing the highest level of water risk.
An Interconnected World That 36 cents a day premium paid by Melburnians also includes the cost of making sure that the city can continue to attract businesses and jobs in the future. But there is still more to it. We live in an interconnected world. If a desalination plant relies on fossil fuels, whatever gains there may be in terms of water sustainability will be squashed under the carbon footprint of the plant. What is required is an approach to the issue of water security that is not at odds with other aspects of sustainability. Australia’s contribution to meeting this challenge is zero impact desalination. Nobody had thought it worthwhile or even possible before, but the six great desal plants changed that. They introduced new areas of science: how do you design an outfall so that the brine diffuses quickly enough for seahorses to thrive around the nozzles? What is the most economic way of handling the pre-treatment reject if you don’t want to flush it out to sea? How do you manage electricity supply from a wind farm when the power demand for a desalination plant is so very different?
The state-of-the-art-desal plant at Wonthaggi in Victoria.
water February 2013
This is the legacy from Australian desalination projects. Late last year I was in California for the CalDesal meeting. They have plans for around 20 large desalination plants along the coast, but none of them are moving forward. The biggest challenge they face is not to do with desalination technology. It is about finding their way through the same environmental issues that Australia’s six large desalination projects had to confront when they were built. That kind of knowledge is where the value-add in desalination is today. It makes the difference between the $0.48/m3 that Hyflux achieved at the Tuas plant in Singapore and the $5.09 paid for desalted water in Melbourne. If you are wondering whether the Australian experience is transferable, I should point out that the conference in California was sponsored by GHD. But it is not just in the desalination program that Australians have learned the soft environmental skills that can add value elsewhere in the world. In the coal seam gas industry, the restrictions on the disposal of produced water are forcing Australian companies to learn new ways of managing brine. They will be invaluable as the global unconventional gas revolution unfolds. Similarly, some of the water management strategies being developed in the mining industry – I am thinking here of things like Fortescue Metal’s managed aquifer storage project in the Pilbara – have global relevance.
The Growth of People Power You might say that since the global financial crisis no-one has money for the environment any more. That is only partly true. Something else has been changing as well as the economy over the past few years: it is the gathering strength of people power. Social networks, mobile phones, message boards – they are making it much easier for ordinary people to voice their opinions and gather together like-minded people to make a difference. It is weakening politicians everywhere – not just in Egypt and Libya. Australia may be a country of weak politicians with fat wallets, but politicians elsewhere are finding it increasingly difficult to ignore the environmental concerns of their voters, and as they don’t have fat wallets, learning from the Australian experience may be the cheapest way to avoid mistakes. So what should be the next steps? It seems to me that you need to get your retaliation in first. If you are going to get companies like Nestlé saying they will only source their cereals from places with sustainable water supplies, it is not just a matter of convincing Nestlé’s management that Australia’s water management is the most sustainable in the world. You need to get involved in the debate and drive it forward to your advantage. You need to engage with the UN Water Compact, the WBCSD’s water initiative, the CDP, the Water Footprint Network, pushing things forward to make sure that water sustainability remains at the top of the corporate environmental agenda. That way your investment in establishing water sustainability can become your competitive advantage in international markets. WJ
• • •
Singapore International Water Week (SIWW) has opened its call for nominations for the Lee Kuan Yew Water Prize 2014. The Prize honours outstanding contributions by individuals or organisations towards solving the world’s water challenges by applying innovative technologies or implementing policies and programs that benefit humanity. Please email email@example.com for more information.
The first intake of seawater into the second stage of the Southern Seawater Desalination Plant (SSDP) in Perth has been conducted. WA Premier Colin Barnett and Water Minister Bill Marmion were on site to activate the flow of seawater into the facility, which will eventually be treated and delivered to the Integrated Water Supply Scheme as drinking water.
Recent analysis conducted by the International Food Policy Research Institute (IFPRI) and Veolia Water has demonstrated that unless more sustainable water resource management practices are adopted by companies and individuals, almost half the global economy and more than half the world’s population will be exposed to severe water scarcity by 2050.
As of 1 January 2013, plastic water bottles that are 1L or smaller have been banned in Concord, a town in Massachusetts, US. According to the Ban the Bottle website, “In 2007, Americans consumed over 50 billion single serve bottles of water. With a recycling rate of only 23%, over 38 billion bottles end up in landfills.”
Kent Street Weir’s contribution to the development of agricultural practices along the Canning River in the early 1900s has been recognised by its inclusion on the State Heritage Register. Heritage Minister, John Castrilli, said the area of Cannington where the weir is located originally contained market gardens watered by the river and also supplied food to the region.
WA Water Minister, Bill Marmion, has announced 173 residential lots at Rockingham would benefit from $2.1 million of vital wastewater services as part of the Government’s Infill Sewerage Program. Mr Marmion said the 173 residential lots would be able to connect to the central wastewater system by October 2013.
In December 2010, the United Nations General Assembly declared 2013 as the United Nations International Year of Water Cooperation. In deference to this, the 2013 World Water Day, which will take place on 22 March 2013, will also be dedicated to water co-operation.
The WA Department of Water has prosecuted a vegetable grower for illegally taking water from the Gnangara mound and deliberately tampering with a state-owned water meter. Department of Water Executive Director Regional Delivery and Regulation, Paul Brown, said the offences were serious breaches of the state’s water legislation.
MIT engineers have created a new polymer film that can generate electricity by drawing on water vapour. The new material changes its shape after absorbing tiny amounts of evaporated water, allowing it to repeatedly curl up and down. Harnessing this continuous motion could drive robotic limbs or generate enough electricity to power micro and nano-electronic devices, such as environmental sensors.
A comprehensive three-year trial of groundwater replenishment was completed by the Water Corporation on 31 December 2012, with some excellent preliminary results attained. Water Minister Bill Marmion said more than 70,000 water quality results had been obtained throughout the trial, and all had met stringent health and environmental guidelines.
The Economist Intelligence Unit has developed a report that looks at the relative preparedness of water utilities across 10 major markets – the US, Canada, the UK, Australia, France, Spain, Brazil, Russia, India and China – to meet future water supply challenges to 2030.
South Australia Following the retirement from Cabinet of Paul Caica, SA Minister Ian Hunter has taken on Sustainability, Environment and Conservation, Water and the River Murray and Aboriginal Affairs and Reconciliation.
National Invading seawater threatens to pollute or destroy scores of Australia’s coastal water supplies, water scientists have warned. In a recent report on the risk of seawater intrusion into coastal aquifers, researchers at the National Centre for Groundwater Research and Training (NCGRT) and Geoscience Australia for the National Water Commission have concluded that more than two thirds of the aquifers they examined were at moderate to high risk of seawater intrusion.
water February 2013
The Murray–Darling Basin Authority (MDBA) has awarded passionate campaigner for the Lower Lakes and River Murray, Henry Jones, the River Murray Medal. MDBA Chief Executive, Dr Rhondda Dickson, said it was the first time the MDBA had awarded the medal to a community member since it was created in 1853.
SA Water has invested over $3.2 million in the south-east of the state to drill new bores to secure water supplies and make disinfection improvements for the towns of Kalangadoo, Naracoorte,
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CrossCurrent Mount Burr and Lucindale. South East Service Delivery Manager, Janina Morrison, says that new bores have been drilled to secure supplies to these towns and surrounds, benefiting almost 10,000 local residents.
Victoria The Victorian Government will provide $1 million to identify feasible water source options for Wangaratta and the surrounding communities. The Water Security for Wangaratta Project will assess alternative water supply options and identify the most cost-effective solution to improve water security in the Wangaratta region.
Researchers at Monash University have developed a nanomaterial that can effectively filter out contaminants in water. Under the leadership of the University’s Dr Mainak Majumder and Phillip Sheath, and Dr Matthew Hill from CSIRO, a group of researchers have found that highly porous Metal Organic Frameworks (MOF) will separate herbicide poisons.
The Victorian Government has released an implementation plan to improve flood-warning systems across the state. The plan is part of the Government’s response to the Review of the 2010–11 Flood Warnings and Response led by Neil Comrie and considers recommendations delivered by the Commonwealth in December 2011. The plan supports the Victorian Government’s goal to help Victorians prepare for and respond to emergencies such as flood events and empower communities to recover quickly.
New South Wales Following a competitive process, Sydney Water has awarded a five-year operations and facilities maintenance services contract, with a further two-year option to Theiss, starting 1 July 2013. Sydney Water Managing Director, Kevin Young, said Theiss will provide mechanical and electrical services for Sydney Water’s water and wastewater treatment plants and networks, and facilities management for more than 2,000 sites and buildings across Sydney, the Blue Mountains and the Illawarra.
The fourth survey to monitor socio-economic performance indicators in NSW water-sharing plan areas will be conducted in the next few weeks. Some 25,000 irrigators in NSW will be invited to express interest to participate in this research.
The NSW Environment Protection Authority (EPA) has launched the eighth NSW State of the Environment (SoE) report, saying the report outlined a number of positive findings and demonstrated the NSW environment’s resilience to severe drought. The NSW State of the Environment Report is prepared every three years to provide the community and decision makers with credible, scientifically based information to assist in the development of environmental policy and manage the state’s natural resources.
water February 2013
This first groundwater status report for the Billabong Creek Alluvium provides information on the groundwater system for resource managers, groundwater users and other interested groups and individuals. These reports describe the physical state of the resources for different areas, provide information on groundwater licensing and use, and discuss the response of the groundwater system to variability in groundwater use and rainfall.
NSW Minister for Finance and Services, Greg Pearce, said Sydney’s Cooks River will be noticeably cleaner following the removal of 10 thousand tonnes of sediment and other waste. Mr Pearce said the $6 million project has taken eight months to complete and was carried out by Sydney Water and Veolia Water Network Services.
The NSW Government has implemented a limit on the purchase of water licences for environmental purposes in the NSW portion of the Murray-Darling Basin. From 15 January 2013, a three per cent limit on further buyback of NSW water licences for environmental purposes in the Murray-Darling Basin will apply. This does not affect trades for consumptive purposes or allocation trades.
The appointment of a new Board for the Sydney Catchment Authority (SCA) has been announced. The new Board appointments extend to November 2014. Robert Rollinson will stay on as Chairman until May 2013 to oversee the transition to the new Board. Mr Rollinson is a highly qualified engineer and administrator with extensive private and public sector experience in infrastructure and utilities.
Following a competitive process, Sydney Water has awarded contracts totalling $500 million, forming the beginning of a framework of contracts to deliver a $1.3 billion investment in essential water infrastructure which will deliver value to customers. Contracts have been awarded for the following services to: Program, Cost and Risk Management – Aquenta Consulting Pty Ltd; Project Management – ISP3, a joint venture organisation between Lend Lease Project Management & Construction (Australia) Pty Ltd and John Holland Pty Ltd; Facility Renewals Delivery Contractors – Process Engineering Technologies Pty Ltd, Abergeldie Contractors Pty Ltd, Downer EDI Engineering Power Pty Ltd and O’Donnell Griffin Pty Ltd.
Queensland A discussion paper has been launched to guide the development of a 30-year water sector strategy to ensure affordable, secure, sustainable and high-quality water and sewerage services across Queensland. The Queensland Water Sector Discussion Paper, designed to facilitate active discussion and participation in creating a new path for Queensland’s water future in urban, rural, regional and remote communities, is a key element of the Newman Government’s Six Month Action Plan. The consultation period for the discussion paper closes on 29 March 2013. The AWA Queensland Branch is preparing a submission. For details contact email@example.com
South-East Queensland’s new single bulk water authority, Seqwater, has commenced operations and will deliver water services
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CrossCurrent across the region. Acting Minister for Water Supply, Andrew Cripps, said legislative changes had been finalised and bulk water supply operations had now been transferred to Seqwater. “The merging of three former water entities – Seqwater, LinkWater and the SEQ Water Grid Manager – as well as some functions of the Queensland Water Commission (QWC) have been consolidated into a single bulk water entity which will allow for better planning and decision making,” Mr Cripps said.
Highlands Water has awarded its engineering support services contract to MWH Global from January 2013 for an initial period of three years.
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A discussion paper has been launched to guide the development of a 30-year water strategy to ensure affordable, secure, sustainable and high-quality water and sewerage services across Queensland. Water Supply Minister Mark McArdle said the Queensland Government is committed to lowering the cost of living. The Queensland Government wants to work with all to ensure a sustainable and affordable water future. Public consultation on the discussion paper closes 29 March 2013. Please visit www.dews.qld.gov.au and search for ‘water sector strategy’.
Member News Danielle Roche will join the Water Services Association of Australia in the position of Manager, Asset Management, based in WSAA’s Melbourne office. Danielle brings a wealth of experience gained at City West Water to WSAA’s asset management program, which she led from October 2009 to January 2012.
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MWH Global has appointed Mr Mark Bruzzone as Australia Regional Director of Government and Infrastructure. Mr Bruzzone’s strong background in engineering and his appointment as Regional Director confirms the commitment of the business to continuing in its position as the wet infrastructure leader around the world.
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February 2013 water
POSTCARD FROM THE MEKONG RIVER DELTA – From Wilf Finn The Mekong River rises in the south-eastern Himalaya Mountains of Tibet, then flows almost 5,000km south through six countries on its way to the South China Sea. The Mekong Basin drains an area of almost 800,000km2 (approximately 80 per cent of the size of the Murray-Darling Basin). Its journey ends in the enormous Mekong Delta (known locally as the Nine Dragon River Delta), which is where our travels south through Vietnam and Cambodia also ended in January this year. By the time the Mekong reaches its delta in southern Vietnam it has coursed its way through China, Myanmar, Laos, Thailand, Cambodia and Vietnam. Mirroring other trans-border rivers around the world (even our own Murray-Darling), it is the source of much conflict over dam construction, water quality, dwindling fishing stocks and seaborne transport. Accordingly, in 1995 the governments of four of those nations (Vietnam, Laos, Thailand and Cambodia), signed the Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin, which established the Mekong River Commission. The Agreement includes the development of a Basin Development Plan (sound familiar?) to: “promote, support, cooperate and coordinate in the development of the full potential of sustainable benefits to all riparian States and the prevention of wasteful use of the Mekong Basin waters, with emphasis and preference on joint and/or basin-wide development projects and basin programs”. The Mekong River Commission has its origins in the Mekong Committee, which was established in 1957 following the granting of independence to Cambodia, Vietnam and Laos from France. Since then, the Mekong has witnessed the battles of the American War (as the Vietnam War is known in Vietnam), the rise of the Khmer Rouge in Cambodia and the subsequent war between Cambodia and Vietnam. The delta that we visited around the southern Vietnamese town of My Tho (a two-hour drive south-west of Ho Chi Minh City) showed few signs of the decades of recent conflict, but instead was a bustling centre on one of the nine major outlets of the delta (hence the local name). The abundance of water-borne food and goods may have masked (or perhaps demonstrated in equal measure) the resource pressures on the river – most memorably the practice of hoisting an example of your wares on your mast for prospective purchasers. Suffice to say, we didn’t have a great need for the barge full of pumpkins that sailed past us at one point. While venturing to the Mekong Delta at the end of our trip, we had also seen its influence a few days earlier when visiting the world’s largest religious monument at Ankor Wat, which was built in the 12th Century near the Tonle Sap (or Great Lake). The Tonle Sap is South East Asia’s largest freshwater lake and plays the role of storage and floodplain for the Mekong, which, during the wet season, backs up into the lake (reversing the usual flow into the Mekong). Our visit was deliberately made in the dry season; however, the villages around the Tonle Sap show the Mekong’s influence when the waters come each year. Within days of our return to Australia, the Mekong River was in the news, as the 19th Mekong River Commission Council Meeting had erupted on its opening day (18 January, 2013) with disagreement between member states about the Lao Government’s construction of the Xayaburi Dam, 350km upstream of Vientiane in northern Laos. The Lao Government is not alone, however, in its dam building ambitions and the Mekong River will face some great challenges in coming years as the economies of its basin countries develop. Wilfred Finn is a member of the AWA Water Journal editorial committee and ‘honeymooned’ to the Mekong in January this year.
water February 2013
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Academy Welcomes New Science Minister The Australian Academy of Science has appointed Chris Bowen as the new Minister for Science and Research. Mr Bowen is known as a Federal MP with a history of commitment to science and research and has assumed responsibility for Tertiary Education, Skills, Science and Research after the resignation of Senator Chris Evans. “The Academy is keen to work with the Minister to foster and grow Australia’s research sector,” said Academy President, Professor Suzanne Cory. “Most developed nations envy our economic success, but we have to invest now in research to guarantee future prosperity through scientific and technological advances.” Professor Cory also thanked Senator Chris Evans. “Former Minister Evans was a strong advocate for science, research and tertiary education…” Professor Cory said. “He also extended crucial Government support to the Academy’s school education programs, Science by Doing and Primary Connections, which will help many more young Australians access high quality science education.”
Water Recycling Fellowships to Build Skills and Partnerships The Australian Water Recycling Centre of Excellence has launched a fellowship program that aims to stimulate collaborative research between the water reuse industry and academia. The water recycling Industry and Academic Exchange Program will provide the opportunity for water industry professionals and researchers (Fellows) to spend time in each other’s worlds to undertake collaborative projects, develop new skills and foster knowledge transfer. Centre CEO, Dr Mark O’Donohue, said the Fellowship represents a significant investment in the sustainability of the national water reuse industry and will result in strengthened working relationships. Exchanges could last up to six months and be used to undertake a full research project, pilot or feasibility study, technical exchange or study of best practice methodologies. Project initiatives may be a proof of concept or allow the required industry/research collaboration to overcome an existing challenging issue within a broader project. Interested water professionals and researchers should visit the Centre’s website at www.australianwaterrecycling.com.au for further information. Applications are due by 28 February, 2013.
Managing Our Water Resources
shows that some catchments have a finite resilience to wet and dry years because they have two steady states. The traditionally held view is that water catchments have only one steady state. A steady state can be considered as how a catchment behaves after a disturbance like a wet year. Traditionally, hydrology has assumed that no matter how wet a year is, once the rain goes back to the average then the stream flow and water table will return to what they were before the wet year. Tim’s work shows that in some catchments, after a wet year the stream flow and water table can return to a very different value. His theories explain how catchments switch between these steady states and how the catchment’s resilience can be measured.
MWH Wins Service Contract Central Highlands Water (CHW), which delivers water and wastewater services to approximately 130,000 residents in more than 60 locations throughout the central and western regions of Victoria, has awarded its engineering support services contract to MWH Global from January 2013 for an initial period of three years. MWH will partner with CHW to ensure skilled staff value add to the performance of the business in asset management, planning, design and construction services to ensure high quality customer service outcomes are maintained. “We are looking to collaborate with Central Highlands Water to provide and transfer knowledge and expertise Peter Robinson (MWH) and Paul O’Donohue in program (CHW) sign the agreement. and project management to optimise its procurement practices and deliver business efficiencies,” said Peter Robinson, Business Development and Strategy Manager, Water Sector, MWH. “MWH was chosen as the organisation’s preferred engineering service provider to deliver increased customer and shareholder value by maintaining CHW’s commitment to providing excellence in customer service standards, while identifying and reducing costs,” said Paul O’Donohue, Managing Director of CHW.
Smarter Decisions for Our Future
Understanding how our water catchments react to natural disturbances may offer hydrologists greater insight into how to manage our water supplies. Key to this is an understanding of the steady state and why water responds differently in different circumstances.
More than 100 water managers and scientists from across Australia met in Canberra recently to develop a vision of how we better measure outcomes from water initiatives across Australia.The recently announced Basin Plan charts a course for water management in the Murray-Darling Basin and the delivery of benefits from the Basin Plan will be achieved by smarter decisions in the way we use water.
Dr Tim Peterson, from the School of Engineering at the University of Melbourne, has offered new theories that will lead to a deeper knowledge of how water catchments behave during wet and dry years. His research was published recently in the international hydrology journal Water Resources Research. Dr Peterson’s work
Associate Professor Michael Stewardson from the University of Melbourne School of Engineering said a co-ordinated effort across government agencies and with the private sector was needed to monitor impacts of the Basin Plan in terms of environmental, social and economic outcomes.
water February 2013
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“This is a complex task requiring innovation in the way we gather, integrate and share information on the water system along with the goods and services it provides,” he said. “New and sustained partnerships between the water industry and research and development sectors are needed to develop the necessary data infrastructure. It isn’t enough to take lots of measurements and prepare reports on how we are tracking in delivering on Basin Plan targets. We need to get this intelligence to the people who are making decisions. This includes decisions made by irrigation farmers and environmental water managers.” Professor Peter Scales from the University of Melbourne Water Productivity and Innovation Hub said: “If we put in place a national system to monitor both the use of water, the benefits we gain from this use and then feed this information back to those in the private and public sectors making water decisions, we will lead the world as a smart water nation.”
Planning and Partnerships for Sustainable Cities The recently released State of Australian Cities 2012 report outlines the progress and performance of Australia’s 18 largest cities. Minister for Infrastructure and Transport, the Hon Anthony Albanese MP, launched the report at a lunch hosted by the Green Building Council of Australia (GBCA). “The State of Australian Cities 2012 report presents an abundance of data and analysis on Romilly Madew our cities and provides us with the information we need to make more informed decisions for the planning, design and delivery of productive, liveable, resilient and sustainable cities,” says the GBCA’s Chief Executive, Romilly Madew. “Cities are a wealth of opportunity, but we must plan for these opportunities - and we must plan now. On current projections we can expect Australia to be home to more than 35 million people by 2050, with up to 85 per cent of the population residing in our cities. The way our cities operate has an enormous impact on our economy, our wellbeing, and our environment.
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“While the Green Star environmental rating system has been focused on buildings for nearly a decade, the Green Building Council of Australia recognises that a city is a collection of buildings, and that we must scale up our efforts if we are to achieve true sustainability in the built environment. The GBCA’s Green Star – Communities rating tool provides benchmarks and a framework to influence the sustainability of entire neighbourhoods, precincts and indeed cities. “State of Australian Cities 2012 provides valuable insights into the current state of Australia’s cities. The next step is to agree on a set of nationally-consistent indicators and a set of best practice benchmarks, such as those already established in the Green Star – Communities rating tool. Working together in partnership to create pathways is the only way for us to ensure we create truly liveable, productive, resilient and sustainable cities.” State of Australian Cities 2012 is available online at: www.infrastructure.gov.au
water February 2013
February 2013 water
Taking care of it
Xylem Water Systems Appoints General Manager John Weaver has been appointed General Manager for Australia and New Zealand of the Applied Water Systems Division of international water business Xylem Water Systems Australia Pty Ltd. He is based at the company’s headquarters in Mentone Victoria. John has had almost 30 years of experience in senior marketing and management roles, with the last 15 years engaged with leading Australian water businesses. “Xylem Asia Pacific has an already strong distributor network in the water technology sector throughout the Asia Pacific region that already provides an exceptionally strong base on which to grow our business,” says John. “I look forward to renewing contact with the many people in the water products sector that I have met and dealt with in my career in the industry.” Xylem Inc is a NYSE listed global water technology provider which does business in more than 100 countries around the globe.
New Regional Director of MWH Global Global engineering and consulting firm MWH Global has appointed Mark Bruzzone as Australia regional director of government and infrastructure. Mark joined MWH in 2001 as a principal process engineer and subsequently served as engineering group manager before transitioning into business development and strategy roles. He previously worked for Sydney Water Corporation, which provides drinking water, wastewater and stormwater services to Sydney, Illawarra and the Blue Mountains.
In his new role, Mark is responsible for guiding the strategy and management of the firm’s urban water, water resources, transportation, and sustainability and environment businesses in Australia. “The Australian water sector is transitioning from a period of capital investment in new infrastructure to looking at how it can optimise its assets to get the most out of them in the future,” said Steve Nye, Asia Pacific president of government and infrastructure for MWH. “Mark’s strength, in part, is his keen understanding of the pressures facing our clients, and his ability to apply this knowledge to shape our business to continually meet our clients’ needs. Additionally, Mark extends his water engineering and management expertise to provide oversight to our rapidly growing water resources, transportation and sustainability and environment offerings.”
Tenix Announces New Infrastructure Division Lead Tenix is pleased to announce the appointment of Trevor Cohen as Executive General Manager of its Infrastructure Division. Trevor will continue to grow and develop Tenix’s infrastructure business, building on the recent success in retaining its power and gas network business in Victoria, as well as winning a number of wastewater treatment plant projects across Queensland. Trevor‘s previous roles include Chief Operating Officer of UGL and Executive General Manager of UGL Infrastructure’s Transport and Communications business as well as senior roles with Transfield Services, Kilpatrick Green and Westinghouse. “Trevor’s depth of experience in managing portfolios of infrastructure projects and successfully growing businesses will be valuable in further establishing the Infrastructure Division’s position in Eastern Australia,” says Ross Taylor, Tenix’s Chief Executive Officer.
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water February 2013
Chairman Appointed for Tasmanian Water & Sewerage Corporation Miles Hampton has been appointed as the inaugural Chairman of the newly formed single statewide Tasmanian Water & Sewerage Corporation, which will open its doors on 1 July 2013. Mr Hampton is the current Chairman of the existing water corporations, which will close their doors on 30 June, making way for the new Tasmanian Water & Sewerage Corporation. The Selection Committee, chaired by Cr Tony Foster, made the announcement after a rigorous selection process.
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The new Corporation will replace Southern Water, Ben Lomond Water, Cradle Mountain Water and its service firm, Onstream – all of which will be amalgamated into one corporation. A trading name for the new Corporation has not yet been identified. Mr Hampton was appointed Chairman of the four existing water corporations – Southern Water, Ben Lomond Water, Cradle Mountain water and Onstream – in January 2011, having been a director since 2008. He was previously Chairman of the bulk water authority Hobart Water from 2005 to 2009. In recent times Mr Hampton led the community debate on rising water prices and has been an advocate for the corporations’ customers.
Crumbling Bores ‘Jeopardise Nation’s Water’ Fifteen thousand collapsing bores – and a half-billion dollar repair bill – are endangering the future of Australia’s largest and most precious resource, its groundwater, according to the Director of the National Centre for Groundwater Research and Training (NCGRT), Professor Craig Simmons. Australian homes, towns, cities, farmers and miners will rely increasingly on underground water as our population grows, surface water supplies dwindle, and as droughts multiply under a warming climate. “Groundwater accounts for about 90 per cent of Australia’s total fresh water reserves – only a fraction is in rivers, lakes and dams on the surface,” he says. “Currently it supplies 30 per cent of our daily water needs – and will be called on a lot more in future. It’s vital for water supplies, agriculture, industry, mining and the environment.” The problem in Australia is that we really do not have a clear idea exactly how much groundwater there is, how rapidly it is recharged – or how quickly it is being depleted. What we do know is based on data largely supplied by 23,000 monitoring bores spread across the continent – more than two-thirds of which are now falling into disrepair, Professor Simmons says. “It’s an old saying: if you can’t measure it, you can’t manage it. Well that is rapidly becoming the case for the one resource which all Australians are really going to need if we are to inhabit this continent in the long term: fresh water.” A report released late last year by the National Water Commission (NWC) documented the state of the nation’s groundwater infrastructure, finding that 68 per cent of our 23,000 monitoring bores were more than 20 years old and at, or near, the end of their useful working lives.
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February 2013 water
The current replacement cost of inoperative monitoring sites was estimated at $318 million, rising to over half a billion dollars if governments continued to ignore the problem, the NWC report indicated. Professor Simmons says there has been a steady increase in use of groundwater by Australian cities, towns and industries over the past 20 years, and especially during the Millennium Drought. “If we are unable to monitor what is going into or being taken out of our aquifers and how groundwater levels are changing, then some communities or industries may find they run out of water without warning. Groundwater is out-ofsight, out-of-mind for most Australians. It is a lot harder to know what you’ve got in the underground water bank than in a river or a dam. Our front line of defence against groundwater running out consists of thousands of monitors, most of which were installed during the 1960s, ‘70s and ‘80s and are now well past their ‘use-by’ dates.” Groundwater is an important water supply in many remote and rural regions but urban groundwater use is expected to grow. Professor Simmons says that although only Perth among Australia’s major cities relies extensively on groundwater, most were now starting to think about how groundwater might augment water supplies as their populations grew, surface resources became strained and the cost of building dams became prohibitive. Adelaide, for example, had previously used groundwater as an emergency drought water supply in the 1970’s and there was no reason why the same idea would not be revisited in times of severe drought. Professor Simmons says that, despite nationwide complacency since the breaking of the last drought “the next drought is already on the way”. The last 200 years have taught us major droughts can be expected several times a century. Climate change is also linked to an increasing number of droughts around the world: there has been drought in a major grain-growing region in each of the last seven years, driving high food prices. “It’s essential that as Australians, living in a dry continent, we don’t get taken by surprise by the next drought – or the ones after it. Part of our strategy for avoiding severe stress on domestic water, the food supply and our native landscape is to monitor and measure underground water. At the moment we are like the driver of a car with an increasingly faulty speedo – racing towards the unknown without having much idea how fast we are going. It is time that everyone – governments, industry, municipalities and the community began to take this issue more seriously.”
water February 2013
Discussion Paper Launched for Queensland The Queensland Government has released a discussion paper on a 30-year strategy for Queensland’s water sector for public consultation. The paper will guide the development of a 30-year strategy to ensure affordable, secure, sustainable and highquality water and sewerage services across Queensland. Water Supply Minister Mark McArdle said the Queensland Government is committed to lowering the cost of living. “It’s vital that we appropriately plan for our future water and sewerage needs, given the cost impact of these services on households, businesses, local governments and community groups,” he said. “All aspects of the water industry will be examined.” The discussion paper is available on the Department of Energy and Water Supply’s website at www.dews.qld.gov.au (search for ‘water sector strategy’). Submissions close Friday 29 March 2013.
John Holland Awarded Two Major Contracts John Holland has been awarded two contracts for major water infrastructure services on behalf of Sydney Water. John Holland will provide the project management services associated with Sydney Water’s Networks and Facilities Renewal Program (NFRP), as part of a joint venture with Lend Lease. The Project Management Service Provider (PMSP) joint venture, will manage Sydney Water’s projects through their lifecycle, from conception to commissioning and handover. John Holland was also awarded a third contract extension for the Priority Sewerage Program (PSP) to deliver additional sewerage works to six communities in environmentally sensitive areas around Sydney. John Holland, as part of the awardwinning PSP Alliance, will deliver program and project management, as well as design, procurement, delivery and commissioning works. Stage 3, which has a total budget of approximately $150 million, is required to be delivered over the next two years.
Salamanca Sewerage Upgrade Completed
WaterSense Photo Competition Winners
The completion this week of a $1.5m upgrade of sewerage
Two stunning images capturing the lifebringing ability of water have taken out the inaugural WaterSense Photo Competition. From a field of over 140 entries, Robert Cassidy’s Nourish and Flourish and Claire Mackintosh’s Watering Can were selected as the winners of the Open and Under-16 categories respectively.
infrastructure in Salamanca will fix long-term sewage overflow problems in the area. Salamanca has long suffered from sewage problems caused by ageing infrastructure, stormwater entry and trade waste discharge, resulting in repeated overflows and odour problems in the area. Southern Water’s $1.5m Salamanca Sewerage Upgrade has seen pipes, valves and electrical systems upgraded, as well as the replacement of the original pump station built 108 years ago. CEO Mike Paine said that the sewer network is now properly equipped to handle waste from the accommodation, bars, cafes and restaurants in the area. “This project has been undertaken to ensure that the sewerage infrastructure in Salamanca meets the needs of such a busy area. The overflow incidents that have occurred in the past in Salamanca are something that nobody wants to see happen in one of Hobart’s most popular dining and entertainment areas, and we have worked hard over the last three years to ensure that the system can now meet demand,” he said.
The winner of the Open category receives a water-efficient washing machine, courtesy of the SaveWater Alliance, while the Under-16 category winner receives $200 cash and a digital camera for her school, Mount Carmel College, in Hobart.
February 2013 WATER
Young Water Professionals
The Power of Passion Jo Greene – AWA YWP National Committee President
My name is Jo Greene and I have recently taken over as President of the National Representative Committee (NRC) for AWA Young Water Professionals (YWP). As this is my first article for Water Journal, I would like to tell you a little about myself. I have now added a passion for water to my longstanding enthusiasm for the environment. After deciding on a career change around 2000, I went back to university to study environmental engineering, and have now been in the water industry for five years. I began at Sydney Water and three years later my family and I moved to Newcastle when I was offered the opportunity to work in Water Efficiency at Hunter Water.
WHEN Challenges MEAN Opportunities I became involved with the Young Water Professionals (YWPs) committee early on in my engineering career and, looking back, find that it has been a constant element along the way. I began as a committee member before moving on to the executive committee, then to the National Representative Committee and now to the role of President of the NRC. It’s as if my role with YWPs has grown and developed alongside my role in the water industry, and I plan for this to continue into the future. Being involved with YWPs has opened up many opportunities for me and I’ve met many people who have become important parts of my life both personally and professionally. I have found that the issues and people that affect us the most
water February 2013
inevitably become more than just ‘work related’. They become part of who we are. It is interesting how we often try to draw lines between our personal and professional lives. How and why do we draw a line between these? How definite does this line need to be? How much does what we do with our careers influence us personally, and vice versa? I believe the answers to these questions are as many and varied as the people and roles within the water industry. I think there are many of us with an essential affinity and passion for the industry that is water. There are the right roles for all of us and when we find them, it becomes more difficult to draw a firm and definite line between ‘home’ and ‘work’. Of course, there definitely needs to be time spent with family and friends, and there certainly needs to be the chance to turn off and have some down time. Indeed, many of us find that is when we become most inspired! Personally, I thrive on the challenges and healthy amount of pressure that can come with a career in the water industry. But challenges are opportunities, and opportunities are what life is all about. It is through the challenges we choose to take on (and how we approach them) that the opportunities present themselves.
Creating Positives From Negatives The devastating floods that recently hit parts of Queensland and New South Wales show how powerful and damaging water can be. Our thoughts went out to those having to evacuate their homes, many for the second time in as many years, waiting
Young Water Professionals to see how high the rivers would flow and what the flood would claim. We empathised with the thousands without power, those isolated by water, and the businesses that could not operate. However, there were still positive elements to be found amidst the disaster. The State Emergency Service, the Army, the Fire Brigade, the Ambulance Officers, the Red Cross, the Salvation Army, the Mud Army, and all the other volunteers are shining examples of humanity at its best, with everyone pitching in together to offer help and support, and no-one giving up hope.
going to achieve nationally this year. I look forward to keeping you up to date on this throughout the course of the year. It could be said that I ended up in the water sector by accident, but then again, many believe there are no accidents in life. Becoming a part of the water industry has become a perfect fit for me. Water is an amazing entity. Nothing on earth is more flexible and yielding than water, yet nothing can resist it. And so it is with me. Now that I’m here, I can’t imagine being anywhere else.
I see 2013 filled with opportunities for the YWPs and the NRC. At the end of this month the committee will hold its annual face to face meeting, and I feel there are going to be some strategic changes for the committee that will be reflected in our action plan and what we are
Photo: NSW SES
It is in challenges like these that opportunities arise. People find ways to help. Volunteers go in and rescue belongings from evacuated houses. People get together to help clean up. There is the issue of clean water. Brisbane, for instance, has a normal consumption of around 450 megalitres per day, and at time of writing utilities were only managing to produce and supply around half of that amount. For those in the water industry in these areas, yes, this at face value is a challenge. But it presents the opportunity for us to band together and find a way to supply this vital ingredient of life to the community.
An aerial photograph showing the recent flooding of the low-lying northern parts of Maclean in northern New South Wales.
Leading-Edge International Water Association
Strategic Asset Management
LESAM 2013 Sydney Convention Centre, Darling Harbour Sydney Australia September 10-12 2013
CALL FOR PAPERS
It is our pleasure to announce the call for papers for LESAM 2013. The conference will be jointly organised by IWA, the IWA Specialist Group on Strategic Asset Management and the AWA – a partnership that will bring together the best that the world's water professionals have to offer. For more information on the conference themes and to submit an abstract please visit the conference website www.lesam2013.org We look forward to meeting you in Sydney.
Dr. Helena Alegre
Mr Paul Freeman
Chair of the IWA SAM Specialist Group
Chair of the Conference Organising Committee
February 2013 water
Tom Mollenkopf Resigns as AWA CEO After six years as Chief Executive Officer of the Australian Water Association, Tom Mollenkopf has announced that he will be standing down from the role in July this year. AWA National President, Lucia Cade, said that the Board and membership of AWA would be sad to see Tom leave. “Tom has overseen a period of considerable growth and change in AWA, at a very exciting time for the water industry. He has worked tirelessly in forging new relationships for the Association both locally and internationally, represented the water industry well, and has increased our member services and grown our membership,” she said. “The Board would like to thank Tom for his invaluable service and extend its best wishes as he resumes fulltime residence in Melbourne. It has been a pleasure working with him over the last six years.” Speaking to staff, Mr Mollenkopf said that the AWA CEO role was one of the most interesting, rewarding and challenging jobs in the water sector in Australia and he was thankful to have had the opportunity to be in the position for six years. “I have immensely enjoyed my time at AWA, including the support and friendship of a very talented group of professionals and a fine Board of Directors,” he said. “I will be returning to Melbourne to pursue various commitments, including Board roles at Western Water, WaterAid, Life Saving Victoria and Surf Life Saving Australia, together with committee roles with the International Water Association.” The AWA Board will now commence a national search for a new CEO.
Get Browsing on AWA’s Website The AWA website now features an Online Bookshop providing access to an extensive range of titles on all aspects of water, wastewater and related environmental fields. AWA has partnered with IWA and AWWA publishing to ensure readers have access to the latest technical publications, in both print and online format. Just like many other online bookshops, we have sought titles compatible with a Print on Demand (POD) publishing model to reduce the time between making a purchase and order fulfillment and the removal of international freight costs. However, AWA will continue to import the more popular hard copy titles not available in POD upon request. AWA members qualify for significant discounts. Please go to www.awa.asn.au/bookstore/landingpage. aspx to browse. AWA has also developed a comprehensive online document library to help you find the latest conference papers and technical papers from Water Journal. The library has an advanced search facility so you can keep up-to-date with the latest in technical information. Check it out today at www.awa.asn.au/awalibrary/ ViewAWAlibrary.
water February 2013
ANZBP Discussion Paper In October 2012, the Australian and New Zealand Biosolids Partnership (ANZBP) launched its Biosolids, Carbon and Climate Change Discussion Paper at a meeting of members in Sydney. The introduction of a price on carbon in Australia on 1 July 2012 provides opportunities for biosolids managers, but may also pose some risks. Initiated by ANZBP members, this paper examines the impact of the Carbon Pricing Mechanism (CPM) on biosolids management. It outlines some critical issues concerning the application of the CPM to biosolids of which operators should be aware, and explores some opportunities for lower carbon outcomes to be delivered through effective biosolids management. The paper also looks at some of the ways in which carbon credits might be generated to the benefit of downstream biosolids users. An early part of the work underpinning this project was a survey of the Australian biosolids industry to obtain information on how well the industry understands the linkages between biosolids and carbon, as well as the implications for biosolids managers of the price of carbon. While there was a broad spread of knowledge, it was clear from the results that the industry’s understanding of these issues is variable and incomplete. The paper begins by reviewing how greenhouse gas emissions from the treatment of biosolids are generated, reported and accounted for. One finding is immediately clear: that the methods used in the CPM to calculate emissions arising from biosolids treatment and management have the potential to over- or under-estimate significantly the emissions generated. In some circumstances this will lead to unjustified carbon price liabilities, while in others a liability that exists in law may not be recognised. These errors in emission calculations arise from the application of multipliers intended to predict emissions from certain treatment processes that are too coarse, or which are relevant to treatment processes used for treatment of sewage, not sewage sludges. For example, only five multiplier ‘options’ are available, whereas there is a wide diversity of treatment processes or combination of processes available. This diversity makes application of the multipliers to particular processes difficult, and there is scant advice as to how this should be done. In short, the CPM regulations are not reflective of on-the-ground operations. Similarly, the emissions methodology for biosolids stockpiles, which is the same as that used for landfills, may lead to an over-estimate of emissions. The impact of this situation is profound. Along with inaccurately determined tax liabilities, wastewater operators are also exposed to real financial and criminal risks, as well as reputational risks if emission estimates are incorrectly made. If, for instance, an audit of emission accounts suggests that an operator used the incorrect methodology and produced an inaccurate emissions estimate, that operator may be considered in breach of the carbon pricing legislation. Sizeable fines and criminal penalties attach to this legislation.
AWA News Conversely, overestimation of emissions may lead to an excessive carbon price liability. A recommendation is made in this paper that additional research is carried out by the water industry in partnership with the Department of Climate Change and Energy Efficiency to make more accurate the methodologies employed to estimate carbon emissions arising from biosolids processing. Biosolids are a potentially valuable resource, the use of which could contribute to the delivery of a low-carbon economy. While it is most unlikely that wastewater facilities will generate carbon credits from biosolids, there is an opportunity for their value in delivering reduced carbon emissions in downstream activities to be recognised. There are three ways in which the downstream uses of biosolids could deliver lower carbon outcomes and derive additional value from biosolids use: 1.
Use of biosolids as a replacement fuel for coal/gas or as a source of biogas, or to generate renewable energy certificates (RECs).
Use of biosolids as a substitute for inorganic fertilisers. In these circumstances, biosolids’ value could be derived from: • Its cost falling relative to inorganic fertilisers as the impact of carbon tax on the cost of the product will be lower; and • Through the development of a methodology under the Federal Government’s Carbon Farming Initiative (CFI).
Incorporation of biosolids into soils to sequester carbon, where a CFI methodology could be created whereby landholders incorporating stabilised biosolids could generate carbon credits.
The introduction of a price on carbon may enhance biosolids’ value to downstream users. To realise this value, however, further effort will need to be directed to demonstrating benefit more clearly. AECOM recommends that the ANZBP undertake further work on biosolids end-use products to determine where the greatest value lies and to identify specific barriers to biosolids uptake by end-users. While on balance the carbon credit opportunities arising from improved biosolids management techniques may not outweigh the entire carbon cost of the wastewater treatment process, it is important to recognise that this issue is shared across the entire water cycle and is not a responsibility of only the biosolids sector to manage. Biosolids management groups are, therefore, not alone, and the opportunity exists to engage other groups working across water management to seek improved outcomes. The ANZBP is committed to working with its members and the wider water industry to address these issues and will work with the sector to explore opportunities to address the concerns at a national level, and will initiate further discussion with members in the near future. If you have specific comments on the report, or are participating in similar activities, please contact the ANZBP Project Manager. The Discussion Paper, and an accompanying presentation, can now be downloaded from the homepage of the ANZBP website: www.biosolids.com.au. To hear about the paper in more detail, and the Partnership’s opinion on the Carbon Pricing Mechanism, AWA is running two Carbon Tax Workshops. Please go to www.awa.asn.au/Carbon_ Tax for more information. ANZBP would like to thank the project consultant, AECOM, for the development of the Discussion Paper.
New Technical Editor Announced AWA has announced the appointment of Chris Davis as new technical editor of Water Journal, taking over from Clare Porter who left recently to take up a position with the National Water Commission. Chris knows AWA well, having been a member since 1982. He also held the role of CEO between 1992 and 2007 and, more recently, became an honorary Life Member. After 40 years spent in a variety of other roles, including as a National Water Commissioner, Chris certainly knows his way around the water industry. In addition to his new AWA appointment, Chris is Chair of the Independent Water Advisory Panel for the NSW Metropolitan Water Directorate.
New President for YWPs AWA welcomes Jo Greene as the new President of the National Representative Committee for the Young Water Professionals. Jo is an environmental engineer and currently part of the Water Efficiency team at Hunter Water Corporation. Before joining Hunter Water, she worked at Sydney Water in the areas of stormwater, environment and sustainability, and project management of large capital projects. Jo is keen to take up the reins and sees 2013 as a year of great opportunity for the NRC to lead the YWPs to achieve more, particularly with their national mentoring program and a greater presence at Career Fairs throughout the country. Jo has taken over the position from Mike Dixon who moved to the US late last year to take up a new role with Nano H2O in Los Angeles.
Branch News Victoria Victorian Water Awards 2012 Leaders in the Victorian water industry were recognised at the 4th Annual Victorian Water Awards held in December. Winners will be automatically entered into the equivalent category in the 2013 AWA National Awards to be announced in Perth at Ozwater’13 in May.
2012 INFRASTRUCTURE PROJECT INNOVATION AWARD: YARRA PARK RECYCLED WATER TREATMENT FACILITY Winner: Tenix Tenix has built Victoria’s largest underground Recycled Water Treatment Facility (RWTF), capable of producing 180ML of Class A recycled water annually. The project was designed to meet the requirements of the Melbourne Cricket Club, with the water used to provide secure, long-term supply to the heritage-listed Yarra Park, Punt Road Oval, and toilet-flushing at the iconic MCG.
February 2013 water
awa News The plant treats and re-uses sewage from the local sewer network, delivering on government management goals and setting a benchmark for others to follow.
2012 PROGRAM INNOVATION AWARD: THE SCHOOLS WATER EFFICIENCY PROJECT (SWEP)
The ACT Branch kicked off its calendar of events for 2013 with the ACT Annual Networking Evening and Technical Seminar. This event was held on Monday 4 February in the Lounge at the Uni Pub, Canberra. The guest speakers for the evening were Mike Rodd, Technical Leader Water Transmission Systems, GHD and Anntonette Dailey, Director, FaHCSIA. The event attendees were given an insight into Mike’s engineering and related experiences that he has encountered during his 40-year adventure in the water industry.
ACT Annual Networking Meeting
Winner: Department of Sustainability and Environment, with the Department of Education and Early Childhood Development SWEP exists to provide subsidised access to data loggers for the purpose of monitoring for leaks and unexpected water use to 500 Victorian schools. A voluntary program, active recruitment of schools, commenced in June 2012 with 90 schools participating at the time of publishing. A Schools Water Efficiency Project website suitable for students, teachers and facilities managers to monitor water consumption trends within their school has been developed and is complemented by a curriculum resource that provides realistic water efficiency messages for students to apply at school and home.
2012 YOUNG WATER PROFESSIONAL AWARD Winner: Kate Simmonds from CH2M Hill Kate Simmonds has worked in the water and wastewater industry for nine years and is passionate about water, the environment and working on sustainable projects. Recently Kate has been involved with a number of projects generating biogas from non-sewage waste streams. Kate’s core strength lies in Project Management and she has experience on major programs including the Hobson Sewer Tunnel (NZ), the Wonthaggi Desalination Plant, the Gippsland Water Factory and Masdar Sustainable City (UAE).
2012 WATER PROFESSIONAL AWARD Winner: Sam Austin from Yarra Valley Water Sam has had a long and distinguished career totalling 38 years in the water industry. After graduating from the University of Melbourne with a Degree in Civil Engineering in 1974, he joined the then Melbourne and Metropolitan Board of Works, and continued his service with its successor Melbourne Water, before moving to the Melbourne water retailer Yarra Valley Water in 1995. His rapid progression and promotion within these organisations is testament to his skills, judgement and ability. Leadership has also been one of his hallmarks. Sam has a keen interest in the ongoing development of the industry generally, where he has made it his business to nurture and support young engineers as well as share his extensive knowledge through counselling and mentoring.
Anntonette Dailey, the recent ACT YWP of Year 2012 award winner, spoke on her experiences leading Commonwealth programs with a focus on the recovery from the Queensland floods and infrastructure in remote communities. The ACT Branch would like to thank both Mike and Anntonette for sharing their experiences, and all those who attended and supported the event. The ACT Branch is now looking forward to its next event – the Enlarged Cotter Dam Tour on 14 March 2013. This event will include a bus tour of Cotter Dam and a post-tour BBQ. Registrations are now open and places are limited, so get in early to avoid disappointment.
nsw New Seminars for 2013 After the success of the 2012 NSW Branch Seminar Series, NSW Branch is adding three more seminars to its portfolio. The first seminar of the series is Recycled Water Supply and Reuse in Regional NSW, which is due to be held on Wednesday 13 March in Newcastle. This seminar will provide attendees with an overview of water recycling and reuse schemes in regional areas. Schemes delivered for urban use, agricultural reuse and industry will be discussed along with current and future projects across the private and research sectors. Registrations for this event are open, with both AWA members and non-members invited to attend. The AWA NSW Young Water Professionals have organised the NSW YWP Careers in Water Evening, sponsored by Sydney Water and to be held at UNSW on Tuesday 19 March. This event is free to attend and we invite students to come along to hear a panel of water industry professionals talk about the various opportunities within the industry, as well as their careers and experiences. Following the presentations there will be an open question session and informal networking, including food and soft drinks.
Leaders in Water Control Solutions Visit our website to see how quality water control infrastructure can reduce your capital expenditure and improve operations. High Head AWMA Segmented Stopboards
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water February 2013
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New Members AWA welcomes the following new members since the most recent issue of Water Journal
NEW CORPORATE MEMBERS
Science & Engineering IA (Australia) Group Ltd
NEW OVERSEAS MEMBERS
Hydroflux Pty Ltd
Corporate Gold Farrier Pty Ltd
CIRS Pty Ltd T/A Creteleak Solutions Pty Ltd
SA Corporate Bronze
Water Utilities Group SEKISUI Rib Loc Australia Pty Ltd
VIC Corporate Gold
Invensys Australia Pty Ltd ISS Facility Services
NORD Drivesystems AU EnviroRisk Management Pty Ltd Water Equipment Plus
WA Corporate Bronze
Kott Gunning Lawyers WISE Water Infrastructure
Corporate Silver Individual Members
NEW INDIVIDUAL MEMBERS ACT J Webb; S Reynolds NSW M Taylor; S Hassan; C Mertens; R Collins; J Breen; D Foley; S Lewer; S Farr; T Bell; V Kippax; C McGarry; N Ulrick; M Bryant; M Teren; I Morris; J Pearson; J Koumoukelis; K Haydon; K Tihirahi; M Rixon; G Pratt; A Davidson; A Layson; A Wright; J Boyle; J Foong; C Katsoulas; A Holmes; K McAndrew; M McGufficke; N Reid; R Harris; R Horner; P Rees; S Marosevac; S Zander; S Bastian; S Carter; V Ridley; J Hook; M Hollands; M Murphy; D Rodriguez; A Kiss; A Butler; R Murphy; R Reynolds; S Rigling; K Stewart; L Lloyd; M Malcolm; M Jones; J Hernage; J Davis;
J Barnes; J Stern; M Thomas; A Alford; A Celona; D Baulch; F Vaarwek; G Veneris; J Schneider NT K Blake; M Welch; M Hodges; M O’Donnell QLD M Potts; K Pither; T Hasan; G Jiang; D Fullerton; M Rowland; W Sando; A Garnsworthy; D Walsh; M Dare; S Iruku; S Hammer; T Fagg; R Connolly; M Taylor; J Perry; J Plumb; A Whitby; C Suggate; K Mitchell; P Thoren; S Cairney; T Low; S Ledger; M Hill; M Vecchio; M Doyle; G Lovelace; C Grey; A Ung; B Millar; B Reck; O Droop; P Wheelhouse; A-M Chapman; E Hamilton; G Cook; M Low SA M Juillerat; M Denny; M Thyer; T Emes; E Gerritsen; E Mann; C Cekavicius; J Wood VIC D Alexander; J Barrios; D Mountford; D Jaduram; C Jakubowski; J van Reyk; M Pendergast; B Trewarn; K Pemberton; R Allen; I Soysa; S Maxwell; S Sawyer; R Ashley; N Young; M Watson; J Allamby; J Bartle-Smith; K Jones; L Pan; L Hickey; A Weaver; A Barnett; G Rohleder; M Carr; M Anthony; N Begue; N Hall; P Dalton; T Sculpher; K Marriner;
N L’Huillier; S Wilson; W Sellars; H Mallen; C Nash; A Namor; D Frenden; E Morrison; J Bartholomeusz WA C Kloppers; M Gillen; K Welch; T Darbyshire; S Carroll; M Scholtemeyer; E Leys; R Green; B Willis-Jones; T Lethbridge; N Higgins; R Rasmussen
NEW STUDENTS MEMBERS NSW H Yu QLD E Eftekhari SA YF Ho
YOUNG WATER PROFESSIONALS NSW R Stenton; X Li; A George NT C D’Cruz QLD C MacDonald; B Goldsworthy; M Irvine; J Johnson TAS A Crawford VIC J McDonald; M Cerutti; C van Enk; N Singh; K Blackhall; K Mosse; K Stephens; YV Ng; V Crouzat; D Phillips WA M Samadi; A Cortier
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
March Tue, 5 Mar 2013 – Thu 7 Mar 2013
Water Education, Water Efficiency & Water Skills National Conference, Sydney, NSW
Wed, 6 Mar 2013
QLD Mentoring Program Launch 2013, Brisbane, QLD
Thur, 7 Mar 2013
Vic Mentor Program – 2013 Launch – Breakfast, Melbourne CBD
Wed, 13 Mar 2013 – Thu 14 Mar 2013
Master Class: Water Quality and the Environment, The Rendezvous Grand Hotel Melbourne, VIC
Wed, 13 Mar 2013
NSW Seminar Series – Seminar 1, Recycled Water Supply and Reuse in Regional NSW, Noahs on the Beach, Newcastle
Wed, 13 Mar 2013
QLD – The Value of Public Assessment – Pricing and Regulatory – Monthly Technical Meeting, Brisbane, QLD
Thu, 14 Mar 2013
ACT Branch Enlarged Cotter Dam Tour, Cotter Dam, ACT
Tue, 19 Mar 2013 – Wed, 20 Mar 2013
Carbon Tax and the Water Sector – Workshop, Brisbane and Melbourne
Tue, 19 Mar 2013 – Tue, 26 Mar 2013
NSW YWP Careers in Water Evening, UNSW & UTS
Wed, 20 Mar 2013
Victorian Desalination Plant – Site Tour, Wonthaggi, VIC
Wed, 27 Mar 2013
QLD – Asset Management Technical Meeting – We Can Learn from Others, Brisbane, QLD
February 2013 water
The Case For Urban Metabolism What is it, and how can it help the water sector? S Kenway, F Pamminger, P Lant
In 2008, Francis Pamminger, Manager, Research and Innovation at Yarra Valley Water, and Steven Kenway, Senior Research Fellow, School of Chemical Engineering, University of Queensland, published a future-oriented view on how the concept of urban metabolism could be of value to the Australian water sector (Pamminger and Kenway, 2008). Four years later, we consider this perspective from the more pragmatic angle of how we can translate this concept into action. Australia’s future cities will need to use water and energy more efficiently than today due to forecasted rapid population growth and limitations in both water and carbon emissions. The Australian Bureau of Statistics projects that if Australian fertility remains at two babies per woman, with net overseas migration rates of 220,000 persons per year (both high-side estimates), then our nation’s population could grow to over 60 million people by 2101 (Abal et al., 2001). With growth such as this, if we want to maintain our standard of living we’ll need to cut our percapita draw on the environment by 75 per cent. Alternatively, we must increase our efficiency by an equivalent amount: a daunting task. Fortunately, the concept of urban metabolism has emerged as a powerful tool that can help discover where cities waste both water and energy. It can also show us how we can use them more effectively.
What is Urban Metabolism? At its simplest, urban metabolism is a technique that considers the flow of water, energy and materials into and out of a city the way one might observe the biological functions of an organism (Newman, 1999; Wolman, 1965; Wolman 1965; Sahely et al., 2003). This perspective differs from the conventional “supply and demand” water balance typically tracked by water utilities. This is because it tracks all flows into and out of the “urban entity”. As a result, urban metabolism creates a different picture of a city’s hydrological performance, highlighting the potential of untapped water sources and previously unidentified discharges that might be reused. The urban metabolism approach also differs from other assessments such as the triple bottom line that accounts across economic, ecological and social goals (Elkington, 1998) and the Ecological Footprint that focuses on carbon accounting only (Sahely et al., 2003). At its most complex, urban metabolism theory lets us compare cities literally with organisms: for example, the water and wastewater networks can be viewed as the arteries and veins, while the treatment plants are the liver or kidneys. The urban metabolism perspective requires us to see the city as a single entity and to evaluate resource flows regardless of origin, ownership, quality or jurisdiction. Basic optimisation theory indicates that it is not possible for us to optimise one system (such as water supply) in isolation. By accounting for all water, including wastewater, stormwater and water “lost” through evapotranspiration we can quickly appreciate the extent to which cities have yet to harness these flows. Even when in the grip of the Millennium Drought and facing “Water Armageddon” (ABC News, 2007), Australian cities still discharged more water as stormwater and wastewater than they distributed for use (Kenway et al., 2011). Some may argue that the Australian water sector has already made vast improvements in the efficiency of water use without considering a unifying vision of a “metabolic city”. For example,
water February 2013
Opinion Over the last 100 years cities have largely overcome challenges using energy. However, when cheap fossil energy ends, our cities must adapt or decline. If we compare the systemic efficiency of our cities with organisms, they are likely to be primitive and, hence, vulnerable. Cities that are water and energy self-reliant will increasingly supply themselves by achieving efficiency and reuse from within. Urban metabolism is a valuable tool if we wish our cities to evolve toward more resilient and adaptable forms. We believe that in adopting an urban metabolism perspective and focusing on efficiency, we will be more likely to create cities that are fabulous places to live. WJ
The Authors Designing cities to be water- and energy-efficient is a major future challenge for planners. Sydney has managed to add a million people to its population without increasing its total water use, through a combination of water efficiency initiatives and a shift towards more compact housing. However, in the wake of significant drought, much of Australia’s recent water security has been achieved with significant energy implication (Kenway et al., 2008; Victorian Water Industry Association, 2011) and there is much scope for the water sector to influence energy use. For example, 13% of Australia’s total electricity use, plus 18% of our natural gas use, is influenced either directly or indirectly by urban water management in cities (Kenway et al., 2011). While approaches to achieving overall city efficiency appear simple, they are complex, interconnected, confusing, value-laden and changing over time. They also involve multiple stakeholders. Consequently, in solving some problems, others are often created. The concepts and tools of urban metabolism can help us to assess and manage these kinds of risks as well as those related to supply chain disruption by natural or human-induced conditions.
Potential for Urban Metabolism Over 100 years ago, the concept of urban metabolism was used to broadly understand all flows of matter between humans and the environment (Fischer-Kowalski, 1998). Today, we have reduced metabolism research to the point of understanding the internal workings of cells. In order to achieve efficient cities by 2100, we believe the concept and application of urban metabolism could lead to aspirational, inspirational and unifying goals for cities and their multi-component water systems (Kenway, 2012). With all these advantages, why then has urban metabolism not been more widely adopted by water and energy utility managers? True, it has been proposed by academics as a framework for dealing with these interrelated issues for nearly 50 years (Wolman, 1965) yet direct translation of theory into practice has not yet begun. Why not? While some may argue that the theory of urban metabolism is too complex, this limitation is increasingly being overcome by better and more integrated data, clearer frameworks, improvements in methods and tools, and a progressive shift towards integrated governance models (for example, the progressive alignment of water and energy policy models). Our argument is that urban metabolism is a highly effective concept for understanding and managing the water, energy and materials efficiency of cities and identifying where interventions are likely to generate the largest biophysical returns. This essay does not propose that urban metabolism theory is a grand universal theory that will solve all problems. The concept needs to be augmented with other concepts to support Australia’s urban future: risk, resilience and cost-benefit analysis (Priestley, 2012).
Steven Kenway (email: email@example.com) is Senior Research Fellow, School of Chemical Engineering, University of Queensland. Francis Pamminger (email: Francis.Pamminger@yvw.com.au) is Manager, Research and Innovation at Yarra Valley Water. Paul Lant (email: firstname.lastname@example.org) is Head of School of Chemical Engineering, University of Queensland.
References Abal EG, Dennison WC & Greenfield PF (2001): Managing the Brisbane River and Moreton Bay: An Integrated Research/Management Program to Reduce Impacts on an Australian Estuary. Water Science and Technology, 43(9), pp 57–70. ABC News (2007): Beattie Scraps Water Poll Amid ‘Armageddon’ Situation, Brisbane. Elkington J (1998): Cannibals with Forks: The Triple Bottom Line of 21st Century Business. Gabriola Island. New Society Publishers. Fischer-Kowalski M (1998): Society’s Metabolism: The Intellectual History of Materials Flow Analysis, Part I, 1860–1970. Journal of Industrial Ecology, 2(1), pp 61–78. Kenway SJ, Priestley A, Cook S, Seo S, Inman M & Gregory A (2008): Energy Use in the Provision and Consumption of Urban Water in Australia and New Zealand. CSIRO and Water Services Association of Australia. Kenway SJ, Gregory A & McMahon J (2011): Urban Water Mass Balance Analysis. Journal of Industrial Ecology, 15(5), pp 693–706. Kenway SJ, Lant P & Priestley A (2011): Quantifying the Links Between Water and Energy in Cities. Journal of Water and Climate Change, 2(4), pp 247–259. Kenway SJ (2012): The Water-Energy Nexus and Urban Metabolism – Identification, Interpretation and Quantification of the Connections in Cities, in School of Chemical Engineering, The University of Queensland, Brisbane, p 176. Newman PWG (1999): Sustainability and Cities: Extending the Metabolism Model. Landscape and Urban Planning, 44(4): pp 219–226. Pamminger F & Kenway SJ (2008): Urban Metabolism – Improving the Sustainability of Urban Water Systems. Water Journal, 35(1), pp 28–29. Priestley T (2012): Towards Assessment Criteria for Water Sensitive Cities, In Technical Report No. 43, UWSR Alliance, Editor 2012, Urban Water Security Research Alliance, Brisbane. Wolman A (1965): The Metabolism of Cities. Scientific American, 213, pp 179–190. Sahely HR, Dudding S & Kennedy CA (2003): Estimating the Urban Metabolism of Canadian Cities: Greater Toronto Area Case Study. Canadian Journal of Civil Engineering, 30(2), pp 468–483. Victorian Water Industry Association (2011): Electricity Issues in the Victorian Water Sector, Victorian Water Industry Association, Editor 2011, Victorian Water Industry Association, Melbourne. Wolman A (1965): : Energy and Material Flow Through the Urban Ecosystem. Annual Review of Energy and the Environment, 25, pp 685–740.
WATER February 2013
a glimpse of the solar future in Spain, which has three large-scale solar thermal plants already in operation, producing 280GWh annually (Torresol energy, 2010).
‘Walking the Talk’: Securing Another Thousand Years (Part 2) As outlined in Part I of this two-part feature in our December 2012 issue, humans have adapted to the planet in a way our ancestors never thought possible. But how will we survive the next one hundred years, let alone one thousand? Andrew Hodgkinson, Senior Principal Technologist, and Sejla Alimanovic, Environmental Engineer, both at CH2MHILL, look at the key issues we face in an over-populated, under-resourced world and how we can address them. Unlike the past where nature shaped the way we lived, we now shape the world. Through the forces unleashed by our global civilisation, we have brought our planet to a threshold. We have initiated an apparent long-term warming trend. Our oceans, rivers and soils are depleted or polluted, and our forests, and many species within them, are declining rapidly. To ensure our survival, we must not only live within our planetary means, but also preserve the ecosystem that sustains us. This is a big task, and one that will only be brought about by changes in our behaviour – we broke it, so shouldn’t we be the ones to fix it?
Identifying the ‘Big Needs’ So what are the key issues we must address? Many would argue that this is a spiritual, or ethical, question. Regardless, ultimately if we are to survive we need food, water and, of course, infrastructure (which, naturally, includes shelter). For reasons of space (and because we are engineers!) we will focus on these physical needs, particularly those related to infrastructure, and also touch briefly on minerals and metals. Firstly though, we must observe that the scale and urgency of the physical problems we face are defined by the size of our population and the intensity of our material consumption. As Ehrlich discusses in his best-selling book, The Population Bomb (1971), our population growth has multidimensional impacts; and as our standard of living improves, the greater is our resource use and the impact of wastes we discharge. China, for example, even though it has largely succeeded in controlling its population growth, still has a rapid growth in materials use and waste output as its economy rapidly expands. However, the
mandatory one-child policy imposed in that country decades ago is, quite understandably, considered an odious infringement on basic human rights. Rather than this, perhaps the most effective and morally acceptable approaches for population control are the education and empowerment of poor people, especially women. Programs such as ‘The Girl Effect’ offer hope in this regard (The Girl Effect, 2012). There are currently seven billion of us on Earth, with about half enjoying a high standard of living and the rest catching up quickly. How would the planet cope with nine or 10 billion with a high standard of living? We need a different way – a way of creating and maintaining material wealth that does not consume the planet, and us. One thing is clear: any reductions we make in resource use and pollution are inevitably counteracted by the combination of population and economic growth, which means these thorny issues must remain a priority for all policymakers, just as important as food, water and infrastructure.
The TechnoSphere – Taking a Lesson from Rainforests Water, energy and food are inextricably linked, and never more so than in the present era. Our habit of supporting our lifestyle from non-renewable sources cannot endure – but there are other options, as nature shows us. A rainforest is an integrated consortium of independently self-sustaining systems. Although rainforests exhibit profuse abundance the soils beneath them are often quite poor (for instance, in south-west Tasmania) and seemingly unable to support
the giant trees and profusion of life growing above. In fact, the dying foliage, fallen fruit, animal droppings and carcasses all provide nutrients that constantly circulate and feed the forest through roots extending into the often sandy topsoil, creating, in effect, a sustainable, wasteless, solarpowered biosphere. The majority of developed society exists within cities and the rest of the world is urbanising rapidly – but modern cities are clearly not wasteless. We must convert them into wasteless technospheres, conceptually similar to rainforests. There will come a time when the cheapest source of many metals will be our landfills. At that point these ‘dump-mines’ will become resources and the concept of ‘landfills’ may disappear. A glimpse of this can be seen in our cardboard, paper, glass and plastic recycling schemes. It is ironic that while we are so focused on our miningderived wealth, it is these resource recycling facilities that will enable and grow our future wealth. Another characteristic of natural systems, including rainforests, is local self-sufficiency. Notably, capture and storage of water, nutrients and conversion and storage of energy is practiced at all levels in the forest, from microscopic (e.g. mitochondria, chloroplasts etc) to the largest scale (e.g. water storage in trees, fat reserves in animals). These are key requirements of any city undergoing conversion into a consortium of ‘self-sustaining systems’. Today, for humans in cities, almost nothing except the air we breathe is obtained locally. Contrast this with the trees lining our streets, which stand silently rebuking our profligacy, while sustainably meeting all
February 2013 water
Feature article their own needs from their immediate surroundings. Trees also derive mutual benefits from other species (e.g. pollination) but their essentially self-sufficient resource usage points to how we must alter our urban resource management approach if we are to cope when our mines are empty.
energy The natural world, including rainforests, is solar powered via photosynthesis. Our technosphere is also solar powered, but by solar energy that was locked up eons ago in fossil fuels. There is only so much energy that can be saved through efficiency. Even after all our energy-consumptive devices are optimised, fitted with LEDs, and variable speed drives, we will still need electricity and other forms of energy. Sunlight harvested directly or by indirect methods such as, for example biomass, hydro, or wind must eventually define the totality of our energy budget. There is no silver bullet that will solve the energy problem, as Jeremy Leggett suggested in his address to the Association for the Study of Peak Oil (ASPO) conference (Leggett, 2012). In a future world where use of fossil fuels is minimal, or possibly outlawed, there will be a variety of renewable energy supplies and this diversity will be a vital aspect of supply security. It is likely that any facility that has need for energy, and has potential to harvest it on site, will do so. For example, medium-scale industrial facilities such as factories and sewage treatment plants will be more energy efficient, utilising low energy processes while also maximising use of biogas, pressure
recovery, wind, tidal, biomass and solar energy capture where feasible. Renewable energy is different to fossil fuelled energy – it is diffuse and intermittent and although it, too, has a ‘peak’, this only represents the maximum yield, not the time beyond which resource yield declines, as with oil. In addition, energy is available almost anywhere, although to gain controllable use of it energy storage using ‘batteries’ of many types must also proliferate. Energy storage systems including solar hot water tanks, latent heat banks, pumped storage hydro and both large and small chemical flow batteries are all available now and are rapidly becoming cheaper. These changes pose profound challenges for existing energy suppliers and it is likely that some of the current energy system monopolies will disappear. These potential changes are comparable to the significant adjustments that occurred as digital cameras displaced chemical photography, and telecom monopolies gave way to mobile telephony. Early signs of these types of changes can be seen in the proliferation of rooftop solar panels and, at a community scale, with the Hepburn Wind Energy Project, where a Victorian community developed a townsized wind power supply (Hepburn Wind, 2012). Also indicative of things to come, Melbourne-based think-tank, Beyond Zero Emissions, is arguing the case to repower Port Augusta with concentrated solar thermal power instead of coal-fired power. China, too, is planning more ‘great leaps forward’, this time with renewable
energy. Bloomberg New Energy Finance on 16 January 2013 reported that China will establish another 49GW of renewable power production during 2013. In peak output terms this is approximately the size of Australia’s east coast grid. The solar industry in China now exceeds that of Germany and continues to expand at a massive rate, meaning that for China a move away from reliance on imported fossil fuels in the next few decades seems feasible. The global political and economic implications of this potential transition should not be underestimated. However, solar is only part of the general trend, with many nations thinking about how best to utilise the natural resources available to them. The UK is heavily invested in wind energy, and is currently well placed to source 30 per cent of its power from wind by 2020 (Renewable UK, 2013). Japan is rumoured to be well positioned as a renewable energy epicentre in the coming years, with its commitment to phase out nuclear in the next three decades (Australia Network News, 2012). The need for the replacement of fossil fuels and near elimination of mining of raw materials is now obvious. Innovations that can enable us to establish and maintain a resource-balanced technosphere are here, now, and we should implement them.
Water Roughly one in 10 people do not have access to clean, fresh water and 2.5 billion people do not have access to sanitation services, resulting in extensive waterborne diseases that kill 2,000 children a day
Wind farms such as this one near albany, in Western australia, are an increasingly useful source of energy.
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sustainability Potable Water
Demand Management Greywater
Sustrainable supply options
and waste even more – globally about onethird of food either fails to reach the table, or is discarded uneaten (Gustavsson et al., 2011). Clearly there is enough food available to feed the starving (World Food Program, 2013) if we wasted less and could transport it to where it is needed.
Improved wastewater treatment
Integrated watercycled management Stormwater reuse Rainwater reuse
Stormwater Integrated Water Management (IWM) managing water in the ‘technosphere’. (WaterAid, 2012). Even countries with a high standard of living such as Australia now face water shortages. The vast majority of the world’s population depends on naturally harvested water; however, about 230 million (3–4% of the global population) rely on desalination of seawater for their needs (Sidem, 2013). Desalinated water is energy intensive and almost all, with a few worthy exceptions, is produced using fossil derived energy. Clearly this cannot continue indefinitely. Integrated Water Management (IWM), which is now receiving strong policy attention in major cities such as Melbourne, is a water system planning approach that applies holistic systems thinking to a catchment to efficiently utilise water resources as well as meet the needs of the surrounding environments. As with energy, returning to the rainforest analogy: IWM offers a model for managing water in the technosphere – especially in our cities. In a recent article, Howe et al. (2012) discuss the key issues of cities of the future, highlighting the need for management approaches that ‘experiment, learn, respond’. We can no longer operate our freshwater systems in a one-directional closed loop, nor can we afford a single high quality water source fit for all purposes. In IWM each process, house, industry and commercial zone is treated like a small catchment within ever-larger catchments. None of these systems are mutually exclusive and their management must consider entire systems, not just immediate human needs.
METALS AND MINERALS Other than energy and water, the other key inputs to infrastructure are metals and minerals. Some metals, such as aluminium and titanium, are plentiful but will continue to be expensive because of high refining and smelting costs or waste outputs. Other metals, such as zinc or platinum, are becoming more expensive because stocks are declining. Price rises help extend the time at which the peak resource occurs, but a higher price does not create more metal. Eventually, possibly because of costs imposed on externalities such as carbon emissions, the price of many metals will be high enough that large scale resource conservation and recycling will develop. ‘Dump mines’ could well become a boom industry in the 22nd century.
FOOD Food is a good example of the material consumption relationships between population and wealth. Currently one in eight people do not have enough food (World Food Program, 2013), so how many will starve in future? As noted earlier, China’s population may have stabilised, but its consumption of everything, including food, is booming. There is no doubt that more people equates to more mouths, but wealthier populations also use more of everything, including food. Is simply growing more food the answer? Just as the fastest and cheapest way to create more energy or water ‘supply’ is via efficiency gains, the same approach applies for food. In western society we eat too much
Stormwater quality improvement
Reduced sewer overflows
Market trade agreements are responsible for some food transport inefficiencies but are important to economic and political security. In a future where fossil fuels and, hence, long distance freight become increasingly expensive it seems likely that a re-emphasis on local production could emerge. However, there are significant unresolved political and economic constraints yet to be resolved. As with population control, this is a thorny issue warranting more discussion than is possible in this article. The related concepts of virtual water and food miles are also relevant here. It may be better to grow certain foods where there is plentiful water, and freight such foods, together with their embodied ‘virtual water’, to drier areas. But it is also worth asking, do we need to freight so many foods so far? It is not uncommon for many Australians to dine regularly on ‘1000-mile’ food. Growing locally reduces the embodied energy from storage and transport; however, land availability and suitability, plus water and nutrient supply are critical elements here. The first essential component for food farming is land. There is still unused arable land left in remote parts of the world (e.g. South America), but we are approaching the limit. As Gilding describes (Gilding, 2011), many countries have invested heavily in purchasing land for food production – as well as deploying defence forces to protect it. The second component is access to nutrients, either naturally occurring or chemically enhanced. As soil nitrogen and phosphorus (the essential building blocks of plants) levels deplete, we must approach food production differently. Nitrogen fertiliser could theoretically be produced using renewable energy, although it is unclear whether this is practicable on the scale required. Artificial phosphorus fertiliser, however, will be impossible to produce once there is little phosphorus left to dig up. Thus, as with metals, large scale nutrient recovery from all types of wastes is likely to be a major new trend and business opportunity. The third key issue for food production is water. Climate change may cause some cropping areas to become drier, forcing development of agriculture in other areas that become wetter. A large-scale transition to more water-efficient farming methods,
FEBRUARY 2013 WATER
Feature article references Australia Network News (2012): Japan’s Ruling Party to Phase Out Nuclear Power, Australia Network News, 28 November, viewed 17 January 2013, www.abc.net.au/news/201211-28/an-japan-nuclear/4395782. Beyond Zero Emissions (2010): Zero Carbon Australia – Stationary Energy Plan, viewed 17 January 2013, media.beyondzeroemissions.org/ ZCA2020_Stationary_Energy_Report_v1.pdf. Bloomberg New Energy Finance (2013): China Unveils Massive Clean Energy Plan for 2013, viewed 17 January 2013, reneweconomy.com. au/2013/china-unveils-massive-clean-energyplan-for-2013-2013?utm_source=rss&utm_ medium=rss&utm_campaign=china-unveilsmassive-clean-energy-plan-for-2013-2013. Ehrlich PR (1971): ‘The Problem’, in The Population Bomb, 2nd Edition, Ballantine Books, New York, p 4. Gilding P (2011): Global Foreshock – the Year that Growth Stopped, in The Great Disruption, Blooomsbury, Great Britain, pp 76–88.
In a rainforest, dying foliage, fallen fruit and animal droppings provide nutrients that feed the roots of the trees, creating a sustainable solar-powered biosphere. reducing the virtual water content of the produce as has been occurring in northern Victoria, is also likely to become much more widespread. There is some hope that genetically engineered self-nitrogenating crops (using legume-type mechanisms), combined with improved pest and drought tolerance features, can also improve crop productivity. If proven and demonstrated to be safe, these will doubtless play a key role. The permaculture movement, which started in Tasmania, may also have some answers (Permaculture Australia, 2012). Permaculture entails a detailed program of crop rotation and views wastes as resources. Permaculturalists recognise that our crops, our livestock and ourselves contain a large amount of phosphorus, so it makes sense that organic waste materials, including human wastes, will be the principal nutrient sources for our food crops. While growing more food is one answer, the resource requirements to do so are significant. Thus increased focus on reducing waste, misallocation and loss will remain priorities, while some increased farming may also occur. However, to maintain current production despite increasingly constrained resources will entail new approaches to nutrient production and conservation, especially phosphorus.
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concLUsIon A famous quote of Theodore Roosevelt’s states: “In any moment of decision, the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing”. It is clear that fossil fuel use and resource exploitation in the past has given major social benefits to many, and it is tempting to sit back and assume this will continue. However, the current fossil-fuelled era cannot last; either the fuel will run out, or we will ruin the planet. Scientific evidence points to the latter occurring first, and soon. While we should retain our centralised infrastructure, we also must re-task it, connecting solar panels, wind farms and storage into a new multi-directional, rather than top down, grid. Likewise our water systems and food supply must adapt, while we ourselves must embrace local micro catchments, practice recycling, and utilise renewable energy. Time will help refine the right path, but turning our cities into a type of solar- and wind-powered ‘rainforest’, integrating everything and wasting nothing, is a course we must eventually take; it’s not the wrong thing – and is far better than doing nothing. WJ
Gustavsson J, Cederberg C, Sonesson U, van Otterdijk R & Meybeck A (2011): Global Food Losses and Food Waste, Food and Agriculture Organisation of the United Nations, Study for the International Congress, Germany, p 4. Hepburn Wind (2012): Hepburn Community Wind Farm, viewed 17 January 2013, hepburnwind. com.au/the-project/. Howe C, Skinner R & Ewert J (2012): Implementing the City of the Future: Tackling the Key Issues, Water21, December 2012, pp 12–14. Leggett J (2012): On the Verge of an Energy Transition, viewed 17 January 2013, www. youtube.com/watch?v=Jrgbt5UBThQ Permaculture Australia (2012): Permaculture… The Beginnings, viewed 17 January 2013, permacultureaustralia.org.au/permaculturethe-beginnings/. Renewable UK (2013): Renewable Energy, viewed 17 January 2013, www.renewableuk.com/ en/renewable-energy/wind-energy/uk-windenergy-database/index.cfm. Sidem (2013): Frequently Asked Questions, viewed 17 January 2013, www.sidem-desalination.com/ en/Process/FAQ/ The Girl Effect (2012): The Girl Effect – About, viewed 17 January 2013, www.girleffect.org/ about/#. Torresol Energy (2010): Plants, viewed 17 January 2013, www.torresolenergy.com/TORRESOL/ plantas.html. WaterAid (2012): The Need, viewed 17 January 2013, www.wateraid.org/international/what_we_ do/the_need/default.asp. World Food Program (2013): Hunger – FAQs, viewed 23 January 2013, www.wfp.org/hunger/faqs.
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Time to innovate – or diE As the water industry takes a renewed focus on business and system efficiency, a commitment to working smarter, not harder, is becoming increasingly important. Claire Dixon explores how to create a framework for innovation that will enable your organisation and projects to flourish. The only constant is change
constrained budgets, increasing community
an innovation journey
expectations, increasingly stringent safety
While it is acknowledged that the innovation activities of an organisation tend to have a higher risk profile than other business pursuits – as well as requiring different methods for measuring value generated – the constant need for smarter work practices, change and renewal are business imperatives that cannot be ignored or avoided.
and environmental regulations and, in
For the past five years, global engineering, architecture and environmental consulting company GHD has been on an innovation journey. This case study explores the key elements of an effective innovation program with reference to GHD’s experience.
In fact, if the familiar adage ‘Innovate or die’ can be believed, the risks associated with an organisation not making changes to their products and services, internal processes and/or business model over time are equally significant, leading if unchecked to extinction and irrelevance. In this respect, it may be a greater risk not to innovate. Whether an organisation is public or private, small or large, operating under boom conditions or within tough economic times, the need to increase efficiency and produce more with less is a common challenge. In addition, impending skill shortages due to an ageing population and the need to mitigate and adapt to the effects of a changing climate are two external drivers of change that will impact most, if not all, organisations in the water sector.
many cases, an urgency to deliver new infrastructure to meet growth in demand. A formal approach to innovation can maximise the chances of doing things smarter. We can do this by streamlining the process, creating clear targets, applying appropriate governance, and influencing the right culture.
A Roman aqueduct at Pont du Gard in France. Aqueducts stand as a testament to Roman engineering and some, like this one, are World Heritage sites.
Rising expectations People have been delivering new ideas that create value for millennia, and the water sector is no exception. In ancient times the Romans constructed aqueducts; more recently we have seen the introduction of drip irrigation to dramatically improve water efficiency in food production, a remarkable rise in the efficiency of membrane water treatment technologies and, right now, we are on the verge of transformation in smart water networks. So if innovation is natural for us, why formalise it? In short, we are under more pressure to do things smarter. In the water sector we’re pushing assets harder and deferring renewals and new works; we have
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Throughout GHD’s 80+-year history, a healthy level of innovation has consistently taken place within the organisation, even in
Innovation Advisory Group Investment gate 1.
Challenges Identify & set objectives
• Submit challenges • Collaborate • Receive specific ideas in response to those challenges
Investment gate 2.
Investment gate 3.
• Let your imagination run wild. • Collaborate with colleagues. • 150 words & image.
• Define idea. • More detail. • Resources required for funded stage?
• Funding provided. • Project team assembled. • Prepare business plan. • Develop prototype.
• Design & do. • Deliver or exit. • Partnerships.
Imagine & collaborate
Define & further collaboration
Refine, collaborate & test
© 2013 GHD Pty Ltd
GHD’s ‘Innovation Pipeline’.
innovation the absence of any dedicated Innovation or Research & Development department. With the company having experienced considerable growth in the past decade to more than 6,500 people globally, and recognising that globalisation, competition and rapid technological changes were changing the face of professional services, it became clear that there was a need to adopt a more structured approach to generating and delivering ideas.
Case Study 1: Real-Time Pump Efficiency Meter System The Challenge Pump systems represent a significant proportion of plant energy and life cycle costs. However, few operators are equipped with the tools, data or know-how to determine whether their pumping systems are operating at their optimal performance level.
The business issues related to idea generation confronting GHD included:
Pump inefficiencies may be caused by worn parts, wrong pumps for application, or changing system conditions. However, the majority of causes are undetectable to the casual observer and so maintenance is not performed in a timely manner, leading to wasted energy and increased operating costs. Existing pump control systems do not monitor pump efficiency and, therefore, cannot detect and notify operators when pump performance deviates from expected output.
• Duplication of effort
• Lack of transparency • Unclear targets and determination of what represented value to the business • Inconsistent capturing of effort and outcomes • Insufficient communication in sharing of learning (success or otherwise) throughout the company In essence, GHD needed to more closely align the process of idea generation and implementation with business strategy and tighten the management of the risks associated with these activities, ensuring that returns were commensurate with the investment required.
For owners and operators of pump infrastructure, there is strong potential to maximise the output of existing assets by being able to effectively monitor and improve pump efficiency in real time. The Solution A GHD water engineer in the US has developed a Real-Time Pump Efficiency Meter System that uses a set of algorithms to calculate the efficiency of pumps operating within pumping systems so that infrastructure managers can identify pumps operating at sub-optimal levels and rectify them in a timely manner. The system is simple to use and can be retrofitted to a wide range of existing plants and pump systems. This system leads to energy savings, and both operating and maintenance cost savings. Since its launch five years ago, more
collaborations have been contributed by
than 1,900 ideas have been submitted
GHD’s people, enhancing the company’s
and 60+ ideas have been delivered or
ability to leverage intellectual capital
received funding for further development.
across geographic boundaries and
Just as importantly, more than 7,000
75 different technical disciplines.
From little things…
Idea selection grid
In response, GHD’s innovation program, known as ‘Innovations’ and led by a dedicated team, was launched in early 2008. Initially, the program focused purely on the ideas of GHD people, and is underpinned by an idea management and collaboration platform called ‘The Zone’ (designed and built by GHD), where all employees are encouraged to submit, collaborate and vote on ideas. The program encourages the contribution of two types of ideas – internal and external: • Internal ideas relate to the improvement of business processes and systems;
Is there another way?
Will value be delivered?
• External ideas relate to clients, the broader industry and revenuegenerating opportunities. All ideas are assessed by an independent management board called the Innovation Advisory Group, in accordance with a transparent selection framework. After passing through two investment gate reviews in the ideas pipeline, the best ideas receive seed funding to enable refinement and testing, with the end goal of delivery by the Innovations team.
Can we add more substance? 1
Chance of Success
What is likelihood of successful implementation?
© 2013 GHD Pty Ltd
GHD’s Idea Selection Grid.
February 2013 water
Case Study 2: Innovation on Projects – Tarago Water Treatment Plant This project was established by Melbourne Water to deliver a new 70ML/d water treatment plant in Victoria. The project was delivered within a relationship framework between client, designer and contractor and utilised the following key innovation framework elements: • An Innovation Champion, as part of the project Quality Key Result Area (KRA) team, whose role was to actively promote innovation keeping it front of mind for all team members; • An Ideas Register that facilitated the recording, evaluation and delivery of ideas meeting relevant KRAs of the project; • A Staged Idea Development Process using evaluation criteria at each of the ‘Raw’, ‘Active’ and ‘Delivery’ stage gates to successfully track, close or progress all ideas contributed by team members; • A Reward & Recognition System, including the awarding of a Gift Voucher each month to the most valuable idea contributed and acknowledgement of contributions in the project team newsletter. Key outcomes from implementing a structured approach to innovation on this project include: • Over 150 ideas generated by the project team • Delivery of the project significantly under budget by challenging traditional functional requirements and incorporating process improvements • Delivery of the project six months ahead of the Victorian Government’s schedule.
Internal ideas delivered to date have saved the company approximately AUD500,000 annually. Many of the ideas have related to the automation of processes, which can deliver significant time and cost savings.
clients. An example of an externally focused
implementation of the program, the
idea currently being delivered is the Real-
GHD team identified opportunities to
time Pump Efficiency Meter System (see
deliver a similar, but tailored, innovation
Case Study 1, page 41).
model on major projects and across other
However, the biggest potential savings come from external ideas that benefit GHD’s
Following the steep learning curve
and implement an innovation program
associated with the launch and early
tailored to its organisational context.
A project focus
organisations. The team is currently working with a water authority in Victoria to develop
Case Study 3: Technology Mentoring Program Case Study – Wastewater Heat Recovery The GHD Technology Mentoring Program focuses on supporting innovative technology providers to deliver smart solutions to water sector challenges. Below is an example of how the program has supported the greater uptake of innovative technologies in the water sector. GeoExchange, a technology provider based in Victoria, has developed a heat recovery pumping technology allowing efficient collection of waste heat discharges for either heating or cooling purposes. Through the Mentoring Program, GHD facilitated a relationship with a water retailer in Victoria to deliver a joint project to identify sites where recovering heat energy from sewers was both technically and commercially feasible. GHD developed a site selection tool for this purpose leveraging sophisticated GIS modelling coupled with technical know-how of heat recovery and commercial insight into end-user decision-making processes. Together the water retailer, GHD and GeoExchange are directly engaging with seven large industrial sites and eight councils with a view to apply this technology to achieve a sustainable and commercially favourable outcome. One large industrial site has already committed to an initial pilot and more than 20 immediate opportunities have been identified with each of the other 15 organisations.
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Case Study 4: Innovation Interchange – A Solution-Focused Global Collaborative Network GHD is a Principal Supporter of the Innovation Interchange, a platform for the global business community to solve industry challenges. In addition to face-to-face engagement, an interactive web portal facilitates peer networking and business connections to find and deliver innovative technology solutions. The beta version of the platform was focused on the water sector and it will expand into other sectors, such as energy and transport, in May 2013. For more information please go to www.innovationinterchange.com On projects, a formal innovation framework drives performance against project objectives, which may include value for money, time, quality, safety and environmental outcomes, as well as improving team cohesion and retention through an open and innovative team culture. A tailored innovation framework was successfully delivered on Tarago Water Treatment Plant project for Melbourne Water (see Case Study 2, opposite page).
Supporting innovative technologies More recently, GHD has recognised the important role that large engineering consulting companies can play in facilitating greater uptake of innovative technologies in the water sector. The Innovations team turned its attention to developing a Technology Mentoring Program, which focuses on supporting technology providers (typically small and medium sized enterprises – SMEs) to develop and deliver solutions to water sector challenges. Rapid population growth, enduring drought in many regions of the world and demand for more energy-efficient, low-carbon-emitting water treatment solutions are some of the drivers combining to create significant technology innovation opportunities within the global water industry. While opportunities for innovation may exist within the global water industry, the ability for innovative SME technology providers to take advantage of these business opportunities can be limited due to a number of barriers including: • An information gap between SMEs and large, national and globally located end users of water related technologies regarding emerging needs; • A credibility gap due to lack of brand recognition within the influential corporate and multi-national sectors. GHD’s Technology Mentoring Program seeks to narrow both of these gaps and deliver tangible outcomes to solve water
sector challenges (see Case Study 3, opposite page for recent examples).
Solving industry challenges GHD’s experience with its own internal program, as well as in delivering innovation on projects and supporting innovative technology providers, has highlighted that successful resolution of a challenge or delivery of an idea usually involves collaboration from multiple organisations. As part of its commitment to leading and facilitating innovation across the infrastructure industry, GHD is Principal Supporter of the Innovation Interchange, a platform for the global business community to solve industry challenges. This is an exciting next step (see Case Study 4, above).
Conclusion It is inconceivable that any organisation has had the luxury at any point of time in history of being able to ignore the pressure to change, without being subject to the high risk of suffering loss to reputation, prosperity and survival in the medium to long term. Given the inevitable need to innovate and change to stay ahead, it is sensible that an organisation should act to equip itself with the necessary skills, processes and systems to manage and mitigate the risks associated with these activities. There are many ways to approach systemising innovation in an organisation
and, while it is impossible to provide a prescriptive ‘one size fits all’ approach, GHD has learnt that there are ingredients that are common to the effective management of all innovation programs. These key ingredients include: • Strategic alignment: The provision of key focus areas to solicit ideas and collaboration that firmly align with the organisation’s strategic objectives, leverage core competencies and have the potential to contribute significant value. • Platform for capturing ideas: Capability to capture fresh ideas and collaboration from a diverse range of sources to ensure effective evaluation and decision-making. • Clear and transparent process: A transparent and efficient ideas pipeline management process with appropriate stage gates that allow for the identification and management of risk, without stifling initiative. • Skills, champions and culture: Innovation project teams assembled and managed by dedicated personnel that are equipped with the requisite skills and have a commitment to delivering practical outcomes. • Measurable outcomes: Clear and transparent measurement of the costs and benefits associated with innovation activities so that investment made is commensurate with desired returns. While it can be tempting to dismiss innovation as a non-core activity within a business, particularly in challenging economic times, we know that ignoring it can leading to false economy, not just in the long term, but in the short term too. A focused, strategic, measurable and transparent process for gathering, assessing and progressing new ideas may indeed be exactly what your business needs to survive, and indeed thrive, in the current economic climate. WJ
About the author Claire Dixon (email: email@example.com) is Innovation Leader (Victoria) and Senior Water Engineer at GHD. Claire studied Civil Engineering (Hons) and Commerce at the University of Melbourne and has over 10 years of experience in the water sector. Prior to working with GHD she worked with Melbourne Water in strategic planning. For more information about GHD’s Innovations program please go to www.ghd.com/innovation
February 2013 water
Changing the Face of Australian Infrastructure A rating scheme developed by AGIC provides a benchmarking tool that sets innovative design, construction and operation standards, helping to place Australia at the forefront of sustainable infrastructure practice. By Tony Wragg. A scheme that evaluates sustainability on infrastructure projects and assets will change the way they are built and operated in Australia. Developed by the Australian Green Infrastructure Council (AGIC), the scheme is Australia’s only comprehensive rating system for evaluating sustainability across the design, construction and operation of infrastructure. It uses an Infrastructure Sustainability (IS) Rating Tool to provide industry with a means to voluntarily assess performance, and be recognised for innovative work. The tool incorporates social, economic and environmental principles that will help place Australia at the forefront of sustainable infrastructure. It also provides a consistent industry ‘language’ to test how sustainability has been considered in the planning, delivery and operation of infrastructure projects. AGIC’s infrastructure sustainability scheme aims to: • Provide a common national language for sustainability in infrastructure; • Provide a vehicle for consistent application and evaluation of sustainability in tendering processes; • Help in scoping whole-of-life sustainability risks for projects and assets, enabling smarter solutions that reduce risks and costs; • Foster resource efficiency and waste reduction, reducing costs; • Foster innovation and continuous improvement in the sustainability outcomes from infrastructure; and • Build an organisation’s credentials and reputation in its approach to sustainability in infrastructure. Like the ‘Green Star’ system that rates the environmental credentials of buildings and communities, AGIC’s scheme focuses on changing behaviour
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and making sustainability a priority on all infrastructure projects. “There is a need to deliver new infrastructure in a manner that protects and enhances not only the environmental aspects of a project, but also its social and economic benefits across an asset’s life,” says AGIC CEO, Antony Sprigg. “In the past, the social and environmental benefits and costs associated with the planning, development, operation and deconstruction of infrastructure assets have not been a primary focus.” AGIC’s scheme builds on current practices by providing industry with an incentive and protocol for assessing, benchmarking and ‘branding’ sustainability performance of infrastructure projects or assets during the design, construction and operation phases. “Earning an IS rating will give designers, builders and owners of infrastructure a competitive advantage and help them keep ahead of the game by ensuring their projects meet the highest sustainability standards,” said Mr Sprigg.
By the industry, for the industry AGIC was formed in Brisbane in 2008 by industry professionals working in engineering, environmental, planning, legal, finance and construction in both the private and public sectors. They recognised that community and government interest in sustainable development was growing, demonstrated through the success of programs like the Green Building Council of Australia’s ‘Green Star’ rating scheme, and identified a gap in the infrastructure space. Under the leadership of David Hood (President of Engineers Australia and a professor at Queensland University of Technology), AGIC developed its charter: The delivery of more sustainable outcomes from the design, construction and operation of Australia’s infrastructure.
The AGIC team secured funding from both the public and private sector and managed the collaborative development of the IS rating tool. The development process included 14 pilot trials. The results from these trials were used to refine the tool before it was launched in Canberra in February 2012 by the Federal Minister for Infrastructure and Transport, The Hon Anthony Albanese. Since the launch, five projects have formally registered for a rating: • A sewage treatment plants upgrade project in the Whitsunday; • A highway project in Western Australia; • An extensive dam upgrade in the ACT; • A large-scale rail project in NSW; and • Infrastructure capital works for a major port in Western Australia. The rating results on three of these projects will be announced in the next few months. In addition there are two more projects currently in pre-registration phase with AGIC.
AGIC’s scheme focuses on changing behaviour and making sustainability a priority on all infrastructure projects AGIC is supported by more than 80 member organisations, which contribute through funding and by sharing knowledge. High profile members include Tenix, Leighton Contractors, John Holland,
This sewage treatment plant in the Whitsunday has registered for a rating.
Transport for NSW, Main Roads WA, Linking Melbourne Authority, ACTEW, Fremantle Ports Authority, Colonial First State, GHD, ARUP, AECOM, SKM and many others.
BenChMArKinG At the ProJeCt LeVeL The primary goal of AGIC is to drive innovation in the delivery and operation of infrastructure assets. “Voluntary performance ratings frameworks based on industry best practice – like the IS tool – not only help drive better environmental and social outcomes, but can also improve business and project performance,” said Mr Sprigg. “We often suggest to members that they could apply management KPIs around the application of our tool. By doing so, they can identify where sustainability considerations can deliver on core business objectives including saving money, reducing risks and informing and streamlining decision processes. The IS tool can be an effective change management and business performance support tool regarding sustainability issues.” Government agencies in particular have become quite specific about their expectations regarding sustainability on new projects. “This tool provides a consistent approach for tenders, allowing them to be reviewed more equitably. Once rated, a project is effectively endorsed/certified by the industry,” said Mr Sprigg.
Peer reCoGnition The work of AGIC has been acknowledged by other sustainability organisations in Australia and overseas, including the Green Building Council of Australia (GBCA), pioneer of the Green Star rating scheme for buildings. GBCA was established in 2002 to develop a sustainable property industry in Australia and drive the adoption of green building practices through market-based solutions. To achieve these objectives, it launched the Green Star environmental rating system for buildings in 2003. Green Star rating tools help the property industry to reduce the environmental impact of buildings, improve occupant health and productivity and achieve real cost savings, while showcasing innovation in sustainable building practices. Green Star ratings are currently available, or in development for a variety of sectors, including commercial offices (design, construction and interior fit outs), retail centres, schools and universities, multi-unit residential dwellings, industrial facilities, public buildings and communities. Since it was established, nearly 550 buildings (covering more than seven million square metres) have received Green Star ratings in Australia. Green Star is now the accepted method of measurement of a project’s sustainability credentials. “We are particularly pleased to have our work acknowledged by the GBCA, which has achieved an enormous amount in this country,” said Mr Sprigg. “Establishing the sustainability nexus between infrastructure and urban development through our symbiotic relationship with GBCA is an exciting, natural and welcome opportunity for AGIC.”
Chief Executive of GBCA, Ms Romilly Madew, agrees. “Our organisations share a common mission to advance sustainability in the design, construction and operation of Australia’s built environment. We are committed to working collaboratively to ensure the best outcomes for industry, government and all Australians,” she said. “It is inevitable that the infrastructure industry will embrace sustainability in the building, operations and maintenance of its assets. There will be real market advantage for those companies willing to take a leadership position in the green infrastructure space, much as the leaders in green building have secured global reputations, seized new business opportunities and shaped the future of their industry.” In addition to maintaining a close relationship with the GBCA, AGIC is also keen to promulgate a global infrastructure sustainability network collaborating with counterparts in the UK and US (where there are equivalent schemes), as well as other nations and global peak bodies also heading down this path.
antony Sprigg (left), aGIC CeO, and aGIC Technical Director rick Walters.
February 2013 water
Feature article hoW the rAtinG tooL WorKs
BuiLdinG the BrAnd
The IS rating tool can be applied across all types of infrastructure including in the transport, water, communication, mining and energy industries, on projects such as water storage and supply, sewerage and drainage, roads, electricity transmission and distribution, airports, railways and bridges. To achieve a rating, the performance of a project is assessed across 15 categories, drawn from six main themes: 1.
Management and governance
Emissions, pollution and waste
People and places
The IS rating tool uses a 100-point scale to measure performance and this score determines a project’s rating level. Supporting the tool is a guideline and technical manual, case study resources, a formal AGIC assessment and verification process, training programs, industry awards and promotion.
Mr Sprigg said AGIC was looking forward to the day when the IS logo is just as recognisable for infrastructure as the Green Star logo is for buildings.
AGIC plans to introduce two more performance themes to the IS tool, for workforce and economic performance, as soon as the necessary sponsorship funding becomes available. However, to achieve its goals AGIC needs to continue attracting new members and building its brand.
“The requirement for an IS rating is already being written into contracts, which is a clear indication that the scheme is already recognised and highly valued,” he said. “We are certainly very excited about what’s ahead.”
“The more projects that are rated, the more improvements will be made to the tool, raising the bar higher. There may also be opportunities to modify the tool to broaden its reach,” said Mr Sprigg. “For example, councils have shown enormous interest in what we are doing. “We are currently working with the Institute of Public Works Engineering Australia and the Australian Centre for Excellence in Local Government (ACELG) on piloting the application of the IS rating tool to Council Road Maintenance Programs. This will help determine if the tool can be adapted to rate smaller assets and capital works projects. This seems logical considering the massive number of projects councils generate every year.”
Celebrating 50 years of Service to Australian Industry
Footnote: A proposal to change AGIC’s name was unanimously supported at the organisation’s AGM held in December 2012. The new name will be the Infrastructure Sustainability Council of Australia (ISCA). It will be officially launched (along with a new logo and other brand elements) in March 2013. WJ Tony Wragg is a freelance business and technical writer with more than 30 years’ experience. An award-winning former journalist, he writes for the water, infrastructure and energy industries.
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GIPPSLAND WATER FACTORY – MEMBRANES AT WORK Competing forces of drought and demand from local industry for additional wastewater capacity created both the incentive and opportunity to solve a 60-year environmental problem in central Gippsland, Victoria. Andrew Hodgkinson from CH2MHILL and Peter Skeels of Gippsland Water describe how the innovative Gippsland Water Factory came about, and some of its key features. intRodUction In addressing 60 years of offensive odours, inadequate wastewater capacity and water supply challenges within central Gippsland, the Gippsland Water Factory (GWF) has established a new standard in total water management encompassing innovative wastewater treatment, water reuse, and education to showcase the water industry as a responsible steward of the environment. Located at Maryvale, in the heart of Latrobe Valley in Victoria (one of Australia’s, and the world’s, most greenhouse emissionintense industrial precincts) using state-ofthe-art membrane treatment technology, the GWF transformed a noxious wastewater system into a sustainable treatment and purified water reuse system that has drastically improved the protection and management of central Gippsland’s water resources.
GWF now stands as an environmental beacon, featuring: • Foundation infrastructure, including breakthrough solutions that set the groundwork for the future reuse of complex industrial pulp and paper wastewater; • Integrated technologies to recycle domestic wastewater for high-value industrial reuse; • enhanced asset life, management practices and operational benefits, greatly reducing chemical costs, greenhouse gas emissions and energy consumption; and • an architecturally inspiring educational centre with programs that are curriculumcompliant and environmentally appropriate for all ages.
bacKgRoUnd Raw sewage had been discharged through a 90-kilometre Regional Outfall Sewer (ROS), almost half of which (40km) was open earthen drain. The ROS had generated strong odour and community angst ever since it was commissioned in 1955. The simple solution – and a safe one from a practical, technical and political standpoint – was to pipe the open drain. However, Gippsland was also in the midst of the most severe drought in living memory, with increasing pressure from industry and agriculture for additional waters from Gippsland rivers. These competing forces created both the incentive and opportunity to solve a 60-year environmental problem and build the foundation for a new way to care for the region’s rivers and lakes and secure central Gippsland’s future water sustainability.
February 2013 water
Feature article GWF now provides an innovative, sustainable and economically responsible reclaimed water solution, transforming the region’s approach to municipal and industrial wastewater disposal, enhancing natural catchments, increasing riverine flows to the Gippsland Lakes, and improving the region’s water supply security. GWF has drastically improved the treated effluent quality discharged to the ROS, while simultaneously achieving an 11–15ML/d water reuse benefit for industry and fodder crop irrigation, with similar water resource extraction reductions. GWF is the first project in Australia to incorporate water recycling into its design from inception, and features an innovative combination of technologies to produce purified water of better quality than that produced at many drinking water plants. It was commissioned in stages and became operational in late 2010, achieving stable operations in early 2011. Its treatment processes rely on biological treatment, membrane filtration and reverse osmosis (RO) to transform nearly 35 megalitres per day (ML/d) of wastewater into a sustainable resource. Wastewater flows comprise 16ML/d of municipal wastewater and 19ML/d of industrial (pulp and paper) wastewater. The municipal and industrial wastewater streams use separate treatment trains customised to their specific source water quality. This enables GWF to economically produce 8–10ML/d of high-quality purified water for industrial reuse at Australian Paper’s Maryvale mill. As a result, the same amount of fresh water (almost 3 billion litres
a year) is freed up in the region’s rivers and reservoirs, enough to supply an Australian town of about 40,000 people. Other streams are reused for agriculture, with the balance available for resale when suitable customer demand is established.
of less than 2 milligrams per litre (mg/L) and total phosphate concentrations of less than 0.1 mg/L as P.
Reclaimed Water Uses
• Highly variable municipal flows, which are severely impacted by wet weather flow peaks;
GWF’s recycled water product is highly purified water produced from the Gippsland’s municipal sewage supply. This high-quality water is now used by Gippsland Water’s largest industrial customer, Australian Paper, the Southern Hemisphere’s largest pulp and paper manufacturer. The water is delivered into the paper mill’s water supply system, reducing demand on its existing raw water supply. In addition, other municipal wastewater streams were reconfigured to enable an additional 4–5ML/d of recycled water for irrigation on Gippsland Water’s 8,000-ha farm at Dutson Downs. During the GWF design, the paper mill’s employees were consulted about their concerns and water requirements, with great care taken to ensure they continued to deliver premium quality product to their customers.
Reclaimed Water Quality and Technical Innovation By using advanced filtration techniques such as membrane bioreactors (MBRs) and RO, GWF’s advanced treatment system produces purified recycled water of better quality than that produced at many drinking water plants around the globe. In addition, the plant meets stringent nutrient standards for its reuse product: total nitrogen concentrations
Significant challenges to achieving this high-quality reuse water included:
• Continual need to balance municipal processing capacity against industrial capacity demands; • Significant industrial treatment train complexities, including: »»High variability of industrial wastewater (quality and flow); some parameters vary daily by a factor of 10 »»Occasional high non-biodegradable organics and sulfur loads (typical for Kraft wastewaters), requiring tertiary treatment to remove strongly coloured refractory dissolved organic carbon »»High degradable carbon loads, but very low nutrient content »»Sporadic toxic load spikes »»Aerobic biomass with strong tendency to slimy bulked sludge (non-settleable and difficult to filter). To ensure premium-quality recycled water for use in any part of the paper mill, GWF was designed with: • Separate treatment of municipal and industrial liquid process trains, with common support facilities to optimise operations. This is a key feature because it segregates higher salinity and strongly
Gippsland Water Factory (GWF) produces 8ML/d of purified water for industrial reuse at Australian Paper’s Maryvale mill, and is also GWF’s main industrial waste customer.
water February 2013
Feature article million expansion of Australian Paper, 600 additional construction jobs were created and 1,000 jobs at the paper mill were secured for the long term. Local communities provide municipal sewage that is GFW purified and supplied to the mill as process water. GWF also uses waste nutrients from residents and a major dairy factory to help economically process the mill’s wastewater and, together with a biogas cogeneration and hydro-power plant, generates 20 per cent of its electricity needs.
Concept diagram of GWF’s nutrient-integrated, but liquid stream-segregated treatment scheme. coloured industrial water for more intense treatment, and protects the RO plant. • Flexible use of membrane bioreactor (MBR) membranes. At peak municipal flows (up to 40ML/d), industrial influent is stored permitting all 12 submerged ultrafiltration membrane cells to treat municipal flow (normally only four cells are used for municipal flow). Including some variations in operating fluxes this permits a peak wet weather to dry weather flow ratio of about 4:1, enabling economical use of otherwise under-utilised wet weather filtration capacity year round. • Use of segregated upstream (catchment) detention storage for industrial and municipal influent. • Anaerobic pre-treatment of industrial influent to mitigate wide-ranging quality variations. These reactors also process domestic sludges to assist the industrial treatment process through the transfer of nutrients from the municipal to industrial process train. • Preparatory design and testing to remove refractory dissolved organics from industrial MBR filtrate (Stage 2). Municipal treatment consists of preliminary treatment, primary treatment, MBR incorporating biological nitrogen and phosphorus removal (BNR), chloramination, RO and chlorine disinfection (BNR is provided to remove excess nutrients for compliance with stringent nutrient requirements, even with RO following it). Industrial treatment consists of anaerobic pre-treatment and MBR treatment without BNR. Provision was made for a future upgrade to the industrial process train to enable increased production of purified water using nanofiltration followed by RO.
The industrial influent is high-strength, nutrient-deficient, and with significant residual non-biodegradable organic matter (derived from Kraft pulping activities) that can rapidly foul RO membranes. It is also heavily laden with sulfate ions arising from the Kraft pulping process. GWF’s unique anaerobic/aerobic/membrane filtration treatment sequence was specifically developed to treat this. The anaerobic pre-treatment step converts degradable organics using a combination of typical anaerobic processes and a greatly enhanced sulfate reduction mechanism. This produces a stream depleted of organics but rich in sulfide for the MBR treatment step. The GWF industrial train MBR includes a special pre-oxidation step (known as H2SOx) that saves up to 75% of the air required for processing the huge amounts of hydrogen sulfide dissolved in the wastewater (typically around 250mg/L as dissolved H2S). This enables a stable aerobic process, readily filterable sludge, and incorporation into the biomass as a precipitate of up to threequarters of the sulfur that is borne within the industrial wastewater. This accumulated sulfur is removed from GWF via the sludge dewatering system, which sends a sulfur and nutrient-rich biosolids material to Gippsland Water’s Soil Organic Recycling Facility, where it is converted into highgrade compost.
Its biosolids are composted and used as soil re-conditioner for one of Victoria’s largest beef farms, providing food for the community and for export, and completing the nutrient cycle, notably in regard to phosphorus. GWF provides foundation infrastructure to permit further expansion of its reused water supply – a significant achievement with huge potential. Through pilot plant testing, Gippsland Water has proven Australian Paper’s difficult-to-treat industrial effluent can be made into water equal to GWF’s current high-quality product. In future, if extra water is required, an additional treatment step can be added at GWF to recycle the industrial stream, creating another 15–20ML/d to replace water currently extracted from the catchment and potentially end the ocean discharge of treated wastewater. Potential customers include Latrobe Valley’s seven major water users, which together consume approximately 300ML/d – about a quarter of Melbourne’s annual water demand.
Effective Management Practices and Operational Benefits Energy, Greenhouse Gas and Chemical Efficiencies
Contribution to the Community
GWF reduces its carbon footprint by generating 20 per cent of its own energy through green energy initiatives. These encompass both a biogas cogeneration system, which also produces hot water for office heating, and a hydro-power plant using the energy derived from raw water entering the process water reservoir for Australian Paper from Gippsland Water’s Moondarra Reservoir in the nearby mountains.
Retrofitted into an existing regional resource system, GWF is a critical component of Gippsland’s industrial and urban ecology. The seven-year GWF project pumped more than $250 million and hundreds of jobs into the local economy. By providing process water that enabled a concurrent $600
Other energy savings are achieved by siting the GWF near large towns and industries to enable the use of existing infrastructure and to minimise pumping energy. Similarly, GWF’s industrial influent is anaerobically pre-treated to reduce energy consumption in subsequent MBR treatment.
February 2013 water
Feature article PRocess validation GWF uses Rhodamine WT (R-WT) fluorescent dye testing to validate its RO system’s virus removal. Developed by CH2M HILL for membrane filtration system integrity testing, R-WT was adopted by the Victorian Department of Health for validating RO pathogen removal and incorporated by the American Society for Testing of Materials into their Standard Practice for Integrity Testing of Water Filtration Membrane Systems.
The regional outfall sewer, which was previously a major source of unpleasant odour in Central Gippsland. Gippsland Water placed a self-imposed greenhouse gas emissions constraint on the project, which for estimating purposes established a $10 per ton carbon cost/value incentive upon the Alliance’s commercial participants. This drove significant energy and carbon efficiency innovation – six years before the carbon tax recently implemented by the Australian Government. The incentives target was to reduce greenhouse gas emissions by 20 per cent off a theoretical benchmark of 52,000 tons CO2 per year. Based on current data, GWF’s greenhouse gas emissions generate 32,000 tons of carbon dioxide equivalent (CO2-e) per year, representing a 38 per cent reduction on the benchmark concept design estimate. GWF also resulted in a 100 per cent reduction in fugitive methane releases from the ROS, as the gas is now captured during the treatment process and used for beneficial reuse electricity generation at the GWF. The decision to focus on “carbon-efficient design” has resulted in additional savings to Gippsland Water. The $23 per ton carbon tax now in force has been avoided because the greenhouse gas emission reductions attained by the project have placed its total direct (i.e., onsite) emissions below the taxable emission threshold. This equates to about $900,000 in carbon tax savings every year, as originally estimated. These savings do not include the much larger value saved by avoided purchases of chemicals and electricity savings totaling around several million dollars a year.
water February 2013
To further optimise its management of materials, water and energy, sludge from the municipal treatment train is digested in the anaerobic reactors, reducing the volume of sludge that must be managed, and providing a nutrient source to support biological treatment of the industrial stream. Biosolids produced by the facility are incorporated into Gippsland Water’s Soil Organic Recycling Facility, where it is converted into a high-grade fertiliser. aUtomated oPeRations GWF has multiple treatment processes distributed over a compact site. The control system provides fully automated facility operations from any plant location, and monitors and records critical operating requirements for compliance reports. Pi Process Book by OsiSoft and an Advanced Computation Engine (ACE) mathematics module, which calculates in real time a wide range of treatment performance and chemical processing parameters, are used by operators and management. Automated data broadcasts keep support specialists around the world up to date on plant trends and status. To allow the continued improvement of operating performance the computer control system includes online trends, including a real-time carbon emission footprint tracking system that allows operators to use live trends of actual greenhouse gas emissions to further optimise the process.
R-WT, as a surrogate for all pathogens of concern, especially viruses, provides an inexpensive, easy-to-apply method for quantifying RO system pathogen removal up to 4-log, both prior to initial operation and periodically throughout operation. R-WT enables Gippsland Water to better assess how well the RO system is performing, improves regulatory reporting, and enhances its ability to produce the highest quality reclaimed water by ensuring optimal pathogen removal – well beyond what can be achieved using conventional surrogates like conductivity or total dissolved solids (TDS). R-WT is an excellent tool that can be used by other water recycling plants to validate their RO systems. GWF also has online dissolved organic carbon (DOC) instrumentation that constantly validates DOC removal log ratio across the RO process. emeRgency and cRisis management Following the disastrous 2009 bush fires in Victoria, Gippsland Water upgraded its emergency and crisis management capability with a fit-for-purpose incident room to provide personnel with a highquality coordination and communications facility. The facility has proven very effective in helping to manage emergency situations to date and provides a modern training facility, which has seen multi-agency use since its completion. GWF also maintains a comprehensive internal safety system, including a wide range of automated safety controls and alarms. Due to the toxic nature of the biogas produced at GWF by the unique anaerobic pretreatment system, a robust biogas management system has also been implemented with multiple layers of redundancy (backup) systems.
PUblic and PRivate sectoR alliance The GWF Alliance, comprised of principal sponsor Gippsland Water and a consortium of CH2M HILL, Transfield Services and Parsons Brinckerhoff, designed, constructed and commissioned GWF, with environmental
innovation sustainability as the guiding vision from inception to completion. GWF’s Alliance structure created an integrated team working collaboratively and sharing equal responsibility for project management, design, construction and operations. This allowed commercial project participants to share project risks and responsibilities, and Gippsland Water to play a key role in GWF design and construction. As the Alliance’s senior project risk/equity partner, CH2M HILL’s staff served most key project roles, including Project Manager, Engineering Manager, Chief Engineer, Technical Director, Technical Advisory Team, Commissioning Manager and Operations Manager. Numerous informal partnerships also proved vital to the development and delivery of GWF, including Gippsland Water’s Technical Review Committee, comprised of the late Professor Peter Cullen, Director for the CRC for Freshwater Ecology; the late Dr Brian Robinson, Chairman of EPA Victoria; Professor Lyndsay Neilson, former Director of the Centre of Developing Cities, University of Canberra; and Dr David Garman, International Water Association (IWA) past president.
Feature article Key relationships were formed with Department of Health, Australian Paper, Environmental Protection Agency (EPA) Victoria, IWA President Dr Glen Daigger, Gippsland Water customers and stakeholders, Monash University Technical Services, University of NSW Centre for Membrane Science, and Griffith University School of Biomolecular Science. To deliver the Vortex and Water Wonders, the GWF Alliance worked with Design Inc. Architects (Australia); Pico Global Services (US); New Media Magic (US); Linda Macpherson, author of From Rails to Trails, (US); and Lee Kindler, co-author of Water, Live it! Learn it! (Australia). Widespread consultation with stakeholders in education, tourism, the environment, business, industry, government and the general community contributed to the ongoing educational outcomes.
PUblic edUcation and oUtReach Gippsland Water has an obligation to provide educational materials to customers and schools regarding the responsible use of water and water conservation. Rather than simply publish pamphlets and place advertisements, Gippsland Water developed
the Vortex Centre, located at the GWF site. Opened in April 2010, it has hosted more than 4,000 visitors to date, including thousands of schoolchildren. Featuring interactive displays, touch-screens, innovative projection and engaging videos, the Vortex focuses on water conservation and sustainable water management, highlighting water as a precious resource at a local, state, national, and global level. The Vortex Centre’s ‘Water Wonders’ program comprises eight programs, designed to be adaptable to all ages. All programs address the Victorian Government’s Education Learning Standards, and for upper secondary or tertiary students, experts and site tours provide a more detailed and enhanced technical experience. With the GWF treatment and recycling plant as the unique backdrop, visitors are provided with a practical example of innovative and responsible water use and management to support the displays. In 2011, Gippsland Water Factory was awarded three Banksia Environmental Awards, including the prestigious overall Origin Gold Banksia Award. WJ
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READY FOR THE DROUGHT... After enduring significant drawbacks and harsh media criticism, the controversial Victorian Desalination Plant at Wonthaggi is now up and ready to run, providing Melbourne with a rainfall-independent source of water to supplement its catchments and storages. The Victorian Desalination Plant (VDP) at Wonthaggi has achieved its final contractual construction milestone of Reliability Testing Finalisation (RTF) following the successful conclusion of a contractually required 30-day continuous production test on 17 December, 2012. The test required the plant to operate at full capacity, producing 450,000m3 of high-quality drinking water per day and delivering it to Cardinia Reservoir. This was preceded by a series of other water quality and production tests, including a requirement to run each 50GL module of the plant for seven days to the ocean to prove water quality, before water could be introduced into the drinking water system. This was achieved with expert input from key project parties, Thiess Degrémont Joint Venture (TDJV), which built the VDP, and Degrémont Thiess Services (DTSJV), which will operate it. According to Chris Herbert, CEO of AquaSure, the company contracted to finance, design, build, and operate and maintain the plant, the ‘best of the best’ worked on the project, which has contributed to an overall positive outcome. “Thiess and Degrémont are leaders in their respective fields of construction
water February 2013
and engineering, and reverse osmosis technology and operations, and they have delivered a great result that will serve Victoria for decades to come,” says Chris.
cOntrOVersiAL BeGinninGs The VDP project was for months subject to controversy due to a demanding delivery timeline, made worse by the rainfall that plagued the scheme and the changed industrial relations climate for all major projects, which led to considerable industrial disputation. In the midst of all this the positive attributes and achievements of the venture were often overlooked. As Chris points out: “People forget that the VDP is one of the largest and most complex infrastructure projects undertaken in Australia in recent years – and in just over 36 months a great deal has been achieved.” During this time several major components were delivered, including: • Construction and commissioning of the 29 buildings that make up the desalination plant site, including the reverse osmosis building, the heart of the VDP; • Construction and commissioning of
two underground tunnels measuring 1.2km and 1.5km long and 4.6 metres in diameter, and associated marine intake and outlet structures; • Construction and commissioning of the 84km, 1.9metre diameter transfer pipeline that will provide water to communities throughout Melbourne, South Gippsland and Westernport, as required; • Building and energising the 87km underground power cable – the longest 220kV HVAC underground power cable of its type in the world. “In that time we clocked up 18 million man-hours with no serious injury, provided employment to more than 10,500 people as part of the direct construction workforce, and many more thousands through the direct and indirect supply chain,” he says.
resPOndinG tO cOmmunitY cOncerns Sensitivity to the local community’s concern about this sudden and major change in their midst, including the visual impact of the plant, the social impact on and protection of the much valued land and marine environment was critical.
Inside the 1.2km underground intake tunnel.
AquaSure and its contractors set up a number of systems and processes to minimise the construction and other impacts on the 6,500 residents of Wonthaggi, the 500 directly and indirectly impacted landowners across the plant and pipeline, and users of the road network across three shires. In response to concerns about the visual impact of the plant on the coastline, the desalination plant was designed to be barely visible from all public viewing points. More than 1.1 million cubic metres of spoil was excavated from the site so that facilities could be constructed at a reduced ground level. Spoil was retained on site and used to construct a series of dunes that help blend the plant with the natural landscape and provide visual and acoustic protection to neighbours. The architectural concept was based on a ‘green line’ that runs through the site, changing form and content as it moves from a natural landscape element to a constructed dune formation, a living roof, a footprint encompassing buildings and, ultimately, a restored landscape. Even though the plant is one of the biggest in the world, it has a very small footprint, taking up just 38 hectares of the 263-hectare site. The remaining 225 hectares, which was predominantly utilised for construction, is the focus of one of the largest ecological restoration projects in Victoria’s history. By the end of 2013, planting in the area will be complete to create wetlands, coastal and swampy woodlands and a new habitat for local fauna. Plants and trees will reinstate the indigenous vegetation cleared over the years to make way for mining and grazing,
and more than 8km of new pedestrian, cycling and horse riding paths are being constructed to link the plant site to existing community trails.
• A regular update from AquaSure’s CEO, Chris Herbert, in the local newspapers • Website • Neighbour doorknocks • Letterbox drops
Throughout construction, TDJV worked closely with members of the local community and business owners to maximise the economic benefit of the facility in the region and to minimise any adverse impact on the community. Prior to work commencing, Thiess Degrémont executed a comprehensive communications campaign including newspaper columns, Fact Sheets and videos explaining the marine design and environmental approval process.
• Open days
A number of information sessions were also held and attended by members of the community and co-hosted by construction engineers and desalination process experts.
During the three years of construction TDJV’s community relations team welcomed nearly 15,000 visitors into the Community Information Centre and engaged with over 10,000 people through community presentations, information sessions, site visits and community events.
Talking with local people about how they might be affected by the desalination plant was an important part of ongoing project implementation. Potential environmental impacts from the marine work were a significant concern for the local community. Being accessible to the majority of the community, local councils, water authorities and other interested parties was also important and AquaSure and TDJV (building on the work that the Department of Sustainability and Environment (DSE) had established in the local area) undertook a number of initiatives to ensure constant and consistent accessibility, including:
• Information sessions • Briefings and presentations • Community committees such as the Community Liaison Group, and Traffic Management Liaison Group • Many of these initiatives will continue throughout the 27-year operations and maintenance phase.
ECONOMIC IMPACT As well as providing a boost to employment, the project generated around $1.3 billion of supply contracts, with three-quarters to Australian companies and two-thirds of these to Victorian companies.
• 24-hour contact line
On the plant site, 100% of the civil component was procured from Victorian or Australian companies, as well as 50% of the mechanical component and 50% of the electrical component. On the pipeline more than 90% of the civil, mechanical and electrical components were procured from Australian or Victorian companies.
• Community Information Centre in Wonthaggi
At the local level the project provided a significant boost to the local economy
FEBRUARY 2013 WATER
Feature article through flow-on demand from a new workforce for housing, products from local suppliers and additional business for retailers and service providers. During construction, local people were employed wherever possible. In addition, more than $500,000 was invested by AquaSure and TDJV in local community support programs, and many new jobs were created within Victorian businesses contracted to provide goods and services to the project. Following community concern about how the project would impact the rental market TDJV, together with the Bass Coast Shire Council, developed a Housing Accord. A new pool of accommodation was made available through holiday homes and investment properties that had not previously been available for rent and those properties were the only properties promoted to employees.
Inside the VDP’s reverse osmosis building.
On the Ground
outcome for the project as it has the least
underground cable. The cable is co-located underground in the same easement as the transfer pipeline. Underground power was the preferred
On the pipeline and power supply easement, 11 crews worked in various locations between Wonthaggi and Berwick, including two mainline crews for long, straight runs of pipe, two smaller mainline crews specialising in difficult terrain, three ‘special crossing’ crews for road and river crossings, three pipe jack crews and a valve installation crew.
impact on landowners and people living
Central to this work was smooth operations between the construction team and the wide range of stakeholders impacted by these works, among them three Councils, road, rail and environmental authorities, utility providers, as well as 125 directly affected and 400 indirectly affected landholders.
A dedicated team was established to maintain relationships with individual landholders and work with them to complete land surveys and property condition reports, as well as negotiate access to properties to allow construction work to occur. The team worked closely with farmers to minimise impacts on cropping and livestock. A Traffic Management Liaison Group met monthly with representatives from Cardinia, Casey and Bass Coast Shire Councils, Vic Roads, Thiess Degrémont Joint Venture, Pipeline Joint Venture, Department of Sustainability and Environment, and Victoria Police to develop and discuss traffic management strategies.
and working in the area and this was a major concession to community concerns early on in the project. The plant and transfer pipeline’s operating power requirements are 100% offset by renewable energy.
KEY Logistics OF THE PROJECT equipment required The quantity of materials required was substantial and included 72 pressurised filters, 51 RO trains (first past and second pass), 15,000 valves, 500 pumps, 200,000 tonnes of concrete and 750km of electrical cable. To manage such a scale, equipment standardisation and off-site fabrication was essential to reduce the construction duration and facilitate mechanical and electrical erection. Logistics such as oversize road transportation had to be well managed. One instance of this was the transportation of 72 massive Dual Media Pressure Filter vessels, which form part of the pretreatment process. Each vessel measures 15 by 4.6 metres and weighs more than 50 tonnes. They were manufactured in China and transported to site from the Port of Melbourne in a series of overnight operations
between September and December 2010,
The plant connects to the existing electricity grid at Cranbourne, some 87km to the north-west, by means of a high voltage alternate current (HVAC)
with up to four vessels moved at a time as
water February 2013
part of convoys more than 500 metres long – one of the longest ever approved for transport on Victorian roads.
Specific infrastructure had to be designed and built to accommodate the plant’s prefabricated modules. The common structures were designed for the final plant capacity of 200GL/y: two 4m diameter tunnels (for a cumulated length of 2.5km); a 1,000ML/d brine diffusion system; a 1,500ML/d lift pumping station; two 35,000m3 storage tanks based on soft bladder technology; an 87 km 220 kV AC underground cable; and an 84km 1.93m diameter cement lined steel pipeline.
Looking to the Future With RTF now complete, water production has ceased and the plant has been put into standby mode. The plant is now in the hands of the operations team, DTSJV, which will manage it until 2039 when it will be handed back to the Government in perfect working order, and without further capital cost to the consumer, ready to produce high quality drinking water for decades to come. In standby mode the full complement of the Operations and Maintenance team, comprising 52 people, ensures the plant remains in full working order, and ready to deliver on demand water security for Victorians of up to 450,000m3 of potable water per day. During this period, water is able to be transferred in reverse flow from Cardinia Reservoir in Melbourne to the various connected water authorities along the pipeline if required. The water quality in the pipeline is continuously monitored by the Operations and Maintenance team as well as DSE and water authorities. With key components of the plant having a design life of 100 years, whether it’s operating at full capacity or in standby mode, the Victorian Desalination Plant will be able to produce high-quality water to meet the needs of generations of people in times of drought. WJ
5th IWA Specialist Conference on
Natural Organic Matter Research
Pan Pacific Hotel, Perth, Western Australia October 1- 4, 2013
CALL FOR PAPERS
Call for Papers It is our pleasure to introduce NOM5 DOWN UNDER, the 5th International Water Association (IWA) Specialist Conference on Natural Organic Matter Research. Jointly organised by IWA, the Australian Water Association (AWA), and the Curtin Water Quality Research Centre (CWQRC), the conference will deliver an excellent scientific program featuring distinguished international keynote speakers, complemented with informative technical tours and unique social activities highlighting the best that Perth has to offer. We invite you to come â€˜down underâ€™ to join us in this exciting Conference, and look forward to meeting you in Perth, Western Australia. A/Prof. Jeffrey W.A. Charrois Chair, Scientific Program Committee Director, Curtin Water Quality Research Centre Dr Ina Kristiana Chair, Organising Committee Research Fellow, Curtin Water Quality Research Centre
Wastewater Management & Treatment Sucrose: The Safe Carbon Dosing Alternative For Wastewater Treatment
A study comparing the SDNR of sucrose to ethanol for the purposes of aiding denitifrication
G Hamilton & J Gualtieri
Ozonation And Biological Activated Carbon Filtration Of Wastewater Treatment Plant Effluents
J Reungoat et al.
M Lee et al.
DJ Batstone & PD Jensen
R Siegrist et al.
SF Barker et al.
W Ahmed, S Toze & JPS Sidhu
An investigation of the fate of trace organic chemicals in three full-scale reclamation plants
An Assessment Of Anammox Implementation For Side-Stream Treatment
A case study of the cost-effectiveness of implementing Anammox at Sydney Water
Impact Of Short-Term Temperature Changes On Anaerobic Digester Performance
Differentials of up to 6°C can be applied for the purposes of recirculation loop heating of digesters
Small Water & Wastewater Systems Onsite And Decentralised Wastewater Systems
Advances from a decade of research and educational efforts
Direct Potable Reuse Do The Australian Guidelines For Water Recycling Protect Small Or Remote Communities?
Many valuable aspects of direct drinking water reuse systems may be particularly useful in small communities
Water Quality Faecal Indicators And Pathogens In Potable Rainwater Tanks In South-East Queensland
The microbiological quality of tank water and connected household tap water in 24 households
APRIL 2013 ‘OZWATER SPECIAL’ AUTOMATION & TELEMETRY CATCHMENT MANAGEMENT
77 Sequencing Batch Reactor-Membrane Bioreactor system established on the CSM campus and used for neighbourhood-scale wastewater treatment and water reuse at Mines Park (Cath, 2012).
WATER FEBRUARY 2013
CARBON FOOTPRINT & GHG GREEN CITIES & INTEGRATED PLANNING
SUCROSE: THE SAFE CARBON DOSING ALTERNATIVE FOR WASTEWATER TREATMENT A study comparing the SDNR of sucrose to ethanol for the purposes of aiding denitrification G Hamilton, J Gualtieri
Sucrose, in the form of molasses, has been used in wastewater treatment for many years. However, molasses presents challenges associated with turbidity, transmissivity, batch variations and excessive impurities. Sucrose, a refined product, is a new carbon source alternative for denitrification in wastewater treatment plants (WWTPs) that are striving for excellence in performance and workplace health and safety.
Understanding the needs of WWTPs, Sucrosolutions has been performing a number of bench and full-scale plant trials across Australia to determine the denitrification kinetics involved when using sucrose as the carbon source. This article outlines a recent benchmarking exercise to compare sucrose against ethanol under controlled conditions. Increased environmental regulations and continual pressure to achieve EPA licensing limits has seen WWTPs in Australia adopting the practice of biological nutrient removal (BNR) as an effective means of reducing total phosphorus (TP) and total nitrogen (TN) levels in their effluent streams. In order to achieve the limits, supplemental carbon sources are often required to assist the biological processes, in particular denitrification, where the COD levels in the anoxic zones are often limited. There is a range of external carbon sources available to treatment plants to assist in the BNR process, for example: ethanol, methanol, molasses, sucrose and
acetic acid. Recognising the potential for a sustainable and non-hazardous nutritive carbohydrate that assists in denitrification, Sugar Australia has developed a sucrosebased carbon alternative called D.NitroTM, a high-grade, refined sucrose solution.
Acknowledging the strength of this product in wastewater treatment, Sugar Australia took the next step to better understand the denitrification kinetics using sucrose, and further benchmark the product with ethanol, another commonly used carbon source on the market. To achieve this, GH Consulting Engineers Pty Ltd (GHCE) was engaged to run a bench scale study, utilising a batch reactor to examine the denitrification rates of sucrose and ethanol, and to compare the overall efficacy of sucrose in the denitrifying process. Gold Coast City Council provided access to an area at the Pimpama Wastewater Treatment Plant as a venue to perform this study. The objective of this investigation was to describe and report on the bench scale test to determine the effectiveness of sucrose as a carbon supplement for denitrification in comparison to that for ethanol.
METHODOLOGY EXPERIMENTAL RATIONALE The batch testing procedure was prepared to enable a comparative assessment of sucrose to ethanol as a carbon source for denitrification. (Note: It was not the
intention of this exercise to develop kinetics for or to demonstrate the performance of sucrose, or ethanol, in a full scale WWTP). The purpose of this exercise was to benchmark and, in addition, observe how sucrose performs under a particular set of operational scenarios in comparison to ethanol. It was assumed that no bias would exist for either ethanol or sucrose under the test conditions, given that the mixed liquor suspended solids (MLSS) obtained from the Pimpama WWTP anoxic zone had no history of carbon dosing. In order to interpret the results obtained from sampling runs and account for any changes in the batch reactor health over time, a spreadsheet was prepared to emulate the batch system’s theoretical nitrification and denitrification performance. The theory for the predictive spreadsheet was based on the IAWQ-Activated Sludge Model (ASM-2) Monod equations with a set of assumed kinetic rate constants considered reasonable for the purpose of this investigation based on GH experience and discussion with industry colleagues. The fixed kinetic rate constants adopted for the purpose of identifying best fit for the data are listed in Tables 1 and 2. Charts were prepared for each experimental run showing the theoretical and recorded data best fit using only the variables for denitrification (Dnu) and % nitrifiers (Xn) to adjust the spreadsheet.
Table 2. De-nitrification constants.
Table 1. Nitrification constants. VSS Yield=
“20 deg. Nitrifier growth rate
“Max. Nitrifier growth rate
“Half sat coeff.NO3-N Temp correct factor
“Nitrifier death rate
“Nitrifiers conc. In VSS
Basic- denit rate
“Half sat coeff.NH3-N
Inhibitory DO mg/l
“Half sat coeff.O2
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WASTEWATER MANAGEMENT AND TREATMENT
WASTEWATER MANAGEMENT AND TREATMENT
Technical Features The denitrification rate used to obtain the best fit was then adopted as the test result for that particular trial run. Ethanol was trialled first in the batch reactor prior to any sucrose addition and then trialled again throughout the experimental period, in the same reactor, to compare to the initial performance and to gauge any impact from the MLSS exposure to sucrose. Table 5 provides a summary of each experiment performed in order. APPARATUS The batch configuration pilot plant consisted of a 200L capacity polyethylene container with independent aeration and mixing. The pilot plant schematic is shown in Figure 1 and was installed at the Gold Coast City Council’s Pimpama five-stage Bardenpho (17ML/day) WWTP. Blower
Raw sewage, carbon and N slug dose during trial runs
Table 3. Dimensions and parameters of batch reactor. Run #
Aeration/ Anoxic timers
Liquid Depth (mm)
BOD load (g/d)
N load (g/d)
MLSS conc. (mg/L)
Type of aeration
Blower– 14 kPa
supplement dosing rates. It was assumed that once the chemical spiking calculations were confirmed with CW they would be reproducible for the mixed liquor (ML) runs. The results for CW Runs #2 and #3 confirmed the theoretical determinations used for the dosing of nutrients, sucrose and ethanol as listed below: • 10mL sucrose provides 9.8g COD at 67% dry solids as experimental external carbon source; • 10mL ethanol provides 16.8g COD at 100% ethanol as benchmark external carbon source; • 2g KNO3 provided 0.27 g NO3-N for nitrate spiking;
Sucrose Feed Sample Point
Figure 1. Pilot plant schematic. Figure 2 provides some photos of the experimental set-up. Mixed liquor for the inoculation of the batch reactor was taken from the WWTP post-anoxic phase and the feed stock of raw sewage was sourced from the screened and de-grit channel of the plant. The sludge age for this WWTP was reported as 15–20 days. CHEMICAL ADDITION The Clean Water (CW) used for this trial consisted of Class A recycled effluent produced at Pimpama WWTP for reuse. This was primarily used to confirm/ calibrate the chemical spiking and carbon
• 2g NH4Cl provided 0.56 g NH4-N for ammonia spiking. OPERATIONAL BASIS The batch process had continuous feed of sucrose on a 24-hour auto timer over the entire trial period from 19 June to 10 July 2012. Five litres of screened raw sewage was added twice weekly to the batch reactor to account for trace elements normally present in WWTPs. Prior to adding the screened raw sewage the system was settled for 30 minutes and 5L of supernatant was removed. There was no wasting from the system other than that lost during a settlement and decant for raw sewage feed and from the 400mL samples taken during each trial run for total suspended solids (TSS) analysis. TSS and volatile suspended solids (VSS) were monitored at the beginning and the end of every trial run.
The external source of carbon was dosed after aeration to assist with dissolved oxygen (DO) draw down until anoxic (<0.2mg/L DO) conditions were achieved. The anoxic conditions then permitted the heterotrophic denitrifying bacteria in the batch reactor to convert NO3-N to nitrogen gas, CO2, water and cell biomass. To ensure that anoxic zones were sustained, the batch reactor had mixing adjusted via by-pass valves on the mixing pump. Too much mixing energy can entrain oxygen from the surface and compromise the anoxic zone, therefore in-situ DO measurements were used to monitor anoxic conditions throughout each trial. The dimensions and parameters of the batch reactor are detailed in Table 3 and the operational basis follows. The batch reactor was operated on the following basis: 1.
The 200L reactor was filled with 150L of MLSS that was kept in suspension by a small mixing pump. This pump operated continuously and recycled MLSS at a rate 0.25 L/sec. The volume of the reactor was turned over at least every 10 minutes, enabling a sampling frequency of 15 minutes.
Aeration was achieved by a small blower and controlled on a timer for intermittent periods. The blower operated against a pressure of 14kPa and a pressure gauge was used to verify consistent operation over the trial period.
Samples were taken from the recycled pump flow as indicated in the schematic in Figure 1 to ensure a representative mixed sample was obtained.
Sucrose only was dosed continuously into the recycle line by a positive displacement pump on a timer, as some acclimation period may be required for optimum performance. Ethanol was only spiked as required
Figure 2. Batch reactor located in the Pimpama WWTP Sludge Dewatering Building.
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Nitrification Rates & reactor conc.
Basis(RUN#4- Ethanol) Theoretical NH3-N Conc
Annoxic Reactor Vol= Batch Feed Vol.=
Rate mg NH3-N/gVSS.hr
DE Nitrification rate
Annoxic period= Influent Ammonia-N in feed= MLSS= VSS=
temp= Nom.DO in Reactor= Init. NO3-N= Init. NH3-N=
L/cycle min min mg/l mg/l % deg C mg/l mg/l mg/l
20 ML ETHANOL (16g)
DO and , Rate mg No3-N/gVSS.hr
150 2 60 180 350 2600 80 20.7 2 0.28 0
Mass Aerobic= 312.0 g Mass Anoxic= 312.0 g
DE- Nitrification Rates & reactor conc. 3
Aeration cycle =
Time in min.
Theoretical No3-N Conc
Aerobic Reactor Volume=
VSS Yield= M@20= Mu= Decay= Xn= Ksn= Kso=
0.10 0.80 0.80 0.06 1.6 1.8 0.8
mg VSS/mg-N "/day "20 deg. Nitrifier growth rate "/day "max. Nitrifier growth rate "/day "nitrifier death rate % VSS "nitrifiers conc. In VSS mg/l "half sat coeff.NH3-N mg/l "half sat coeff.O2
Ksdn= Dntf= Dnu= Dnu= Ko=
0.8 1.1 1.9 0.4 0.2
mg/l "half sat coeff.NO3-N temp correct factor Ethanol denit rate -mg NO3-N/gVSS.h basic denit rate-mg NO3-N/gVSS.h inhibitory DO mg/l
Time in min.
Figure 3. Predicted and actual results for Run#4 using ethanol as first carbon source (SDNR=1.9). The top chart represents the ammonium concentration in blue. The bottom chart is NOx-N concentration in yellow. (Figures in red are variables.) Nitrification- Denitrification
Nitrification Rates & reactor conc.
Basis(RUN#15 SURCOSE and Ethanol)
12 ML SUCROSE(16 g)
10 ML ETHANOL (8g)
Mass Aerobic= 442.4 Mass Anoxic= 442.4
Aeration cycle = Annoxic period= Influent Ammonia-N in feed= MLSS= VSS=
temp= Nom.DO in Reactor= Init. NO3-N= Init. NH3-N=
DE Nitrification rate
1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289
DO , and mg No3-N/gVSS.hr
carbon Test Results
Batch Feed Vol.=
Theoretical No3-N Conc DO
150 0 5 120 220 3687 80 23 2 0 0.03
Annoxic Reactor Vol=
Time in min.
DE- Nitrification Rates & reactor conc.
Aerobic Reactor Volume=
1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289
Rate mg NH3-N/gVSS.hr
Theoretical NH3-N Conc
Time in min.
L/cycle min min mg/l mg/l % deg C mg/l mg/l mg/l
VSS Yield= M@20= Mu= Decay= Xn= Ksn= Kso=
0.10 0.80 1.00 0.06 0.8 1.8 0.8
mg VSS/mg-N "/day "20 deg. Nitrifier growth rate "/day "max. Nitrifier growth rate "/day "nitrifier death rate % VSS "nitrifiers conc. In VSS mg/l "half sat coeff.NH3-N mg/l "half sat coeff.O2
Ksdn= Dntf= Dnu= Dnu= Dnu= Ko= Nitrate=
0.5 1.1 1.9 2 0.5 0.2 4.4
mg/l "half sat coeff.NO3-N temp correct factor Sucrose rate -mg NO3-N/gVSS.h Ethanol rate - mg NO3-N/gvss.h basic- denit rate-mg NO3-N/gVSS.h inhibitory DO mg/l mg/l spiked
No aeration and mixing only
Sucrose dosing at 180mL/Hr for 15 min in each cycle
• Carbon limiting and NOx-N in excess • Excess of NOx-N and Carbon. Spiking of ammonium (NH4Cl) and nitrate (KNO3) was required to benchmark
Two examples of runs performed are shown in Figures 3 and 4. (Note: Variables are shown in red in Figures 3 and 4). Test Results refer to either NOX-N or NH3-N, as the chart axes in Figure 3 indicate.
The SDNR rates for both ethanol and sucrose are tabulated in Table 5. Each of the figures in this table has been used to determine a single SDNR value, which is represented in Figure 5.
• NOx-N limiting and carbon in excess
RESULTS There was a total of 15 trial runs performed to determine standard denitrification rates (SDNR). Approximately 300 nutrient analyses, 55 COD and 20 VSS tests were taken during the trials. The results were assessed using a predictive spreadsheet to determine best fit to the laboratory results. The predicted scenario requires at least five data points for determination of a single SDNR outcome.
This study did not set out to confirm growth rates or yield coefficients, so generally accepted values for heterotrophic growth rates, including death rates, were adopted for the purpose of these trials as set out on page 1.
Experimental runs were designed to test:
All other parameters were analysed by GCW-NATA Laboratory and all samples were filtered on site immediately after the sample was taken to remove any colloidal solids that could impact nutrient analysis. A vacuum pump was used as a first-stage filtration followed by a 0.45 um filter cartridge on a syringe. 30mL samples were taken for nutrient analysis while 200mL samples of MLSS were taken for VSS and TSS analysis.
denitrification, using sucrose against ethanol under the same carbon and nitrate limited conditions. Spiking of ammonium was used on a limited basis to assess nitrification capacity as an indication of MLSS health.
Table 4. Typical cycle times.
The cycle times were based on hours and are displayed in Table 4.
Testing was undertaken by Gold Coast City Council NATA Laboratory, with all sample vessels and chemicals provided by the laboratory, and samples provided by GHCE. Although this assessment relates primarily to NOx-N, the other parameters also monitored included: NH3-N; COD (Total); VSS/TSS; pH; DO; Temperature.pH was checked weekly and found to have little variation from 7.2–7.4. DO and temperature were measured using an in-situ probe, which was calibrated daily by the Pimpama WWTP operators.
The actual results shown as black squares in the case of ammonia and black triangles for NOx-N are plotted with nitrification/ denitrification rates determined using the predictive spreadsheet, which was developed using kinetic rates and variables as listed. The results from each trial would yield a single data point for denitrification rate (indicated by the red value Dnu). Subsequent runs use the same methodology while trialling alternate configurations and concentrations for both nutrients and carbon. (Note: Given the absence of reliable data for similar trials of this nature, the methodology was subject to informed amendment to ensure robustness of the trials.)
Figure 4. Predicted and actual results for Run#15 using first sucrose then ethanol as carbon sources. (Figures in red are variables.)
SAMPLING AND LABORATORY ANALYSIS
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WASTEWATER MANAGEMENT AND TREATMENT
Technical Features preferred configuration for this trial as it provided Denitrification Rates a rapid and robust NOx-N Carbon Dose SDNR achieved comparison, particularly Period mg/l Rates(mL/batch) mgNOx-N/g.vss.h as the MLSS was taken from a working BNR Anoxic Run Run# Date Day # Initial Final Sucrose Ethanol Sucrose Ethanol wastewater treatment Time(min) plant. In this case, the R4 19 Jun 0 4.5 0 – 20 85 1.9 150L batch reactor was R5 20 Jun 1 15 12.8 12 – 65 1.2 useful in offsetting the R6 21 Jun 2 14.2 10 – 7 84 1.8 impact of a 15-minute sampling frequency and R7&8 25 Jun 6 60 57.6 12 – 70 1.2 natural variability in the R9 26 Jun 7 62 57 12 – 132 1.4 MLSS sample used. The R11 28 Jun 9 59 56 12–30 – 85 1.3 batch reactor was initially R12 29 Jun 10 35 29 30 20 104 2.1 1.8 filled with Class A effluent to confirm assumptions R13 4 Jul 15 8.5 6.5 1.4 – 35 2.1 with respect to theoretical R15 10 Jul 21 4 0 12 10 72 1.9 2 determination for COD and nutrient spiking, The results for SDNR achieved through which compares various carbon sources, and was found to correlate well with the including sugar, methanol and ethanol the study indicate an upward trend for the calculations. The batch volume was then over longer periods of time using low seed sucrose over a 10-day period, followed replaced with MLSS from the post anoxic concentrations from Blue Plains AWTP. The by an apparent step change to a rate zone of the Pimpama WWTP and the study was aimed at assessing growth rates, similar to that for ethanol. The implication 21-day trial period commenced. SDNR and process kinetics for the different of these results is that the use of sucrose carbon supplements under stringent will achieve similar SDNR performance as In order to determine an unbiased experimental controls. It was concluded ethanol, and also appears to suggest that background SDNR for ethanol it was that sugar and acetate would likely have the denitrifiers needed time to acclimatise the first to be trialled and an SDNR value significantly higher denitrification rates of 1.9 mg NOx-N/mg VSS.hr recorded. to the sucrose over the 10-day period. because of their metabolising heterotrophs Subsequent trials with sucrose and ethanol The actual amount of NOx-N removal having higher specific growth rates (page confirmed that their SDNR was very similar achieved may vary and will depend on the 235, ref i). Dold also described a possible after an initial period of 10 days of dosing particular process configuration in which acclimation period for biomass to optimise with sucrose, as indicated in Figure 5. An the carbon supplement is applied, as well SDNR of 2mgNOx-N/mg.VSS.hr has been sucrose uptake. An increasing SDNR was, as the existing microbial population. The adopted as an outcome of this study. This therefore, another possible observation. rates determined from this study, however, performance may not be the same for are considered conservative based on DISCUSSION continuous flow studies; however, as the work by others reported in a paper titled The batch configuration adopted for this rates recorded are generally below those ‘Final Report – Protocol to Evaluate Carbon study was undertaken to benchmark the of work reported in the two references Sources for Denitrification at Full Scale Sugar Australia product D.NitroTM compared thus far, they are considered conservative. Water Treatment Plants’ (WERF/IWA, 2010). with pure ethanol as an external carbon Although this study was comparatively The findings in this study are supported supplement for enhancing denitrification brief, it did show that the SDNR for sucrose rates. The 150L batch process was the by another paper (Dold et al, 2007), was similar to that for ethanol after an apparent acclimation period of at least 10–12 days. Table 5. Trial results used in analysis.
CONCLUSIONS The bench scale studies for Sugar Australia, undertaken at Gold Coast City Council’s Pimpama WWTP, have demonstrated the value of sucrose as an external carbon supplement for the purpose of enhancing denitrification. SDNR performance has been benchmarked against another industry accepted carbon supplement, ethanol, and found to have similar performance.
Figure 5. Summary SDNR for sucrose and ethanol over the trial period.
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It is recommended that controlled studies at a full scale WWTP be undertaken as the next level of investigation to gain a robust understanding of the sucrose economies and performance based on the information obtained from this study.
Sugar Australia acknowledges the valuable contribution to this study of Gold Coast City Council and, in particular, Kelly O’Halloran and Dion Sleep, and the Pimpama Wastewater Treatment Plant (WWTP) operators in arranging for the area at Pimpama WWTP to be made available for the denitrification trials. The advice provided by GCCC NATA laboratory personnel in regard to analytical methods and John Terry for the monitoring and sampling throughout the trial period is also acknowledged.
Geoff Hamilton (email: email@example.com) is Principal of GH Consulting Engineers, Gold Coast. He is a Civil Engineer with a professional career spanning more than 35 years. Geoff worked with the Kyogle Shire Council in 1970 before moving to Toowoomba City Council as a Project Manager, then headed up R&D at Gold Coast City Council in the Water Supply and Sewerage Sector. He undertook the Australian Water Research Advisory Council (AWRAC) project to research social and scientific issues impacting the longer term introduction of potable reuse of reclaimed wastewater. Geoff also worked with Gold Coast City Council for nine years in Infrastructure Planning. He has worked with key research organisations ANSTO, CSIRO and University of Queensland looking at water treatment schemes, water harvesting, bulk transmission, manganese removal, nutrient survey and monitoring. In recent years Geoff has been consulting to the industry in civil, structural and water and wastewater infrastructure.
Disclaimer: The information contained in this document is not to be construed as a representation or warranty as to its content and is to the best of our knowledge and belief true and accurate at the date it was prepared, namely 11 January 2013. It pays no regard to your intended use and is not intended to be used where that would be in breach of a third party’s intellectual property rights including patent, design and copyright. It is purely provided by way of assistance and should not be quoted or parts extracted without the express approval of Sugar Australia Pty Ltd.
Mono Pumps Over 70 Years Waste Water Pumping Experience
Josephine Gualtieri (email: jgualtieri@ sugaraustralia.com.au) is the Technical Manager, Sucrosolutions for Water, Sugar Australia. In this capacity, Josephine provides engineering support to WWTPs in relation to dosing with sucrose, to provide safe and sustainable solutions to improving effluent outflows. Prior to undertaking this role, Josephine worked as a Process Engineer within Sugar Australia’s sugar refinery and has also worked within the mining industry as a Chemical Engineer with BHP Billiton in South Australia, working primarily on process improvement projects and leading pilot plant initiatives.
REFERENCES Dold P, Takács I, Mokhayeri Y, Nichols A, Hinojosa J, Riffat R, Bailey W & Murthy S (2007): Denitrification with Carbon Addition – Kinetic Considerations, Water Environment Federation, 2007. WERF/IWA (2010): Water Environmental Research Foundation (WERF). Co-published by IWA. Protocol to Evaluate Alternative External Carbon Sources for Denitrifying at Full-Scale Wastewater Treatment Plants, Final Report.
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FEBRUARY 2013 WATER
WASTEWATER MANAGEMENT AND TREATMENT
WASTEWATER MANAGEMENT AND TREATMENT
OZONATION AND BIOLOGICAL ACTIVATED CARBON FILTRATION OF WASTEWATER TREATMENT PLANT EFFLUENTS An investigation of the fate of trace organic chemicals in three full-scale reclamation plants J Reungoat, BI Escher, M Macova, W Gernjak, J Keller
SUMMARY This study investigated the fate of trace organic chemicals in three full-scale reclamation plants using ozonation followed by biological activated carbon filtration to treat wastewater treatment plant effluents. Chemical analysis was used to quantify a wide range of trace organic chemicals and combined with bioanalytical tools to assess non-specific toxicity and estrogenicity. The combination of ozonation and biological activated carbon filtration achieved removals of up to 50% for dissolved organic carbon and more than 90% for a wide range of trace organic chemicals, as well as a reduction of 70% of non-specific toxicity and more than 95% of estrogenicity. This process combination is, therefore, suggested as an effective barrier to reduce the discharge of trace organic chemicals into the environment or their presence in water recycling schemes, including indirect potable reuse.
INTRODUCTION The presence of a large variety of anthropogenic organic compounds at trace levels (typically Âľg L-1 and below) in domestic wastewater has been reported worldwide, including Australia (Reungoat et al., 2010). These contaminants of emerging concern are commonly designated as trace organic chemicals (TrOCs). Among them, pharmaceuticals have received particular attention since they have been designed to be bioactive. While some are effectively removed by conventional biological treatments, others are barely affected. As a result, pharmaceuticals are released into surface water via wastewater treatment plant (WWTP) effluents and this situation is of concern as it has been shown to impact aquatic life (e.g. feminisation of male fishes).
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Moreover, even though there is no evidence of impact on human health, the precautionary principle should be applied in the case of planned or unplanned indirect potable reuse. The presence of TrOCs in drinking water sources should be avoided, as conventional drinking water treatments are ineffective to remove them. Therefore, additional steps have to be considered for the advanced treatment of WWTP effluents to reduce the discharge load of TrOCs into sensitive receiving waters and their presence in water recycling schemes.
this by investigating additional plants and assess the impact of the ozone dose and the empty bed contact time (EBCT) in the BAC filters on the effectiveness of the process. For that purpose, chemical analysis for the quantification of TrOCs was combined with in-vitro bioanalytical tools, as they complement each other to evaluate water quality and process effectiveness (Macova et al., 2010; Reungoat et al., 2010; Poulsen et al., 2011).
Several technologies have proven to be effective in removing TrOCs from water of various qualities: activated carbon adsorption, ozonation and advanced oxidation and high-pressure membrane filtration. High-pressure membrane filtration, and particularly reverse osmosis, very effectively removes TrOCs from treated wastewater but concentrates them in a waste stream representing up to 20% of the treated volume. Activated carbon adsorption and ozonation are considered economically feasible options for advanced treatment of WWTP effluents (Joss et al., 2008). However, ozonation is known to lead to the formation of transformation products largely not identified to date, which raises concerns regarding their potential impact on the environment and human health. Activated carbon removes TrOCs from water, but it has to be renewed or regenerated regularly to maintain its adsorption capacity.
Three full-scale wastewater reclamation plants located in Australia were investigated (Figure 1). All the plants receive treated effluent from WWTPs with biological nutrient removal. After various pretreatment stages, they all use ozonation followed by BAC filtration before final disinfection using various technologies. However, the ozone dose and EBCT in the BAC filters differ from one plant to another, providing different operating conditions. The specific ozone doses at the time of sampling were 0.2-0.3, 0.4-0.5 and 0.6-0.8Â mgO3 mgDOC-1 for Landsborough, Gerringong and Caboolture respectively. The granular activated carbon used in the BAC filters was from various origins.
In a previous comprehensive study of one full-scale reclamation plant we showed that ozonation followed by biological activated carbon (BAC) filtration has the potential to significantly remove TrOCs and reduce non-specific and specific toxicity levels of WWTP effluents (Reungoat et al., 2010). In the present study, we wanted to confirm
MATERIALS AND METHODS
At Caboolture, the filtering media had been replaced in March 2008 and the samples were collected in July 2010, by which time approximately 68,000 bed volumes had passed through the filter. The BAC filters were commissioned in 2003 at Landsborough and the media had not been renewed since, leading to more than 350,000 bed volumes filtered at the time of sampling (March to June, 2010). Finally, at Gerringong, the four BAC filters were commissioned in 2002 and the media of two filters was renewed in August 2009. Therefore, at the time of the sampling
Table 1. Water quality parameters in the reclamation plants before the ozonation stage (N/D = not determined).
quantified TrOCs were detected before ozonation, with concentrations varying from low ng L-1 up to µg L-1 levels, showing their incomplete removal in the WWTPs. It is interesting to note that the concentrations of most of the compounds remained in the same order of magnitude across the three plants, despite the different locations and sampling times. This shows how ubiquitous these compounds are in treated effluents as well as a regular consumption pattern within Australia.
22.6 – 28.5
6.6 – 6.7
6.7 – 7.1
6.7 – 6.9
Conductivity (µS cm )
879 – 910
392 – 507
520 – 563
DOC (mgC L-1)
6.5 – 8.1
5.8 – 6.6
4.2 – 5.8
PO4 (mgP L )
0.22 – 2.00
NH4+ (mgN L-1)
0.22 – 0.45
0.18 – 1.36
NO2- (mgN L-1)
0.03 – 0.06
< 0.02 – 0.04
NO3- (mgN L-1)
<0.02 – 0.95
0.18 – 0.47
0.39 – 1.14
Baseline-TEQbio (mg L )
1.83 – 2.72
1.50 – 2.01
1.10 – 1.84
Baseline-TEQchem (µg L-1)
1.74 – 2.62
3.31 – 5.81
2.77 – 2.97
0.10 – 0.11%
0.19 – 0.29%
0.15 – 0.26%
0.98 – 1.73
1.13 – 1.44
0.57 – 1.53
In Caboolture, which uses the highest ozone dose, a slight removal of 5% to 10% of DOC was observed, but in the other plants DOC was not affected by the ozonation stage (Figure 2). At the doses employed, ozonation led to limited mineralisation and to the production of transformation products.
T (°C) pH -1
Baseline-TEQchem/ Baseline-TEQbio EEQ (ng L-1)
campaign in September 2010, half of the media had filtered approximately 95,000 bed volumes and the other half had filtered about 13,000 bed volumes. Given the large numbers of bed volumes filtered in each plant, it is reasonable to assume that all the filters have passed the breakthrough of organic matter and adsorption is negligible. Dissolved oxygen concentrations measured before and after filtration through the BAC showed a decrease confirming that they were biologically active. Three sets of grab samples were collected from each plant before ozonation, after ozonation and after BAC filtration. Dissolved organic carbon (DOC) was measured after filtration of the sample through a 0.45 μm nylon membrane. Fortyone TrOCs were quantified by a method consisting of solid phase extraction, elution, concentration, and analysis of the extract by liquid chromatography coupled with tandem mass spectrometry (Reungoat et al., 2012). Estrogenic activity was quantified with the E-SCREEN assay to assess a receptormediated mode of toxic action that is a critical end point relevant for WWTP effluents. The assay was performed as described in Macova et al. (2010), and the results expressed as the estradiol equivalent concentrations (EEQ). Many previous studies have shown a good agreement between EEQbio (determined by the bioassay) and EEQchem (calculated from the estrogenic compounds concentrations and their relative estrogenic potential) and, therefore, estrogenic chemicals were exclusively quantified by bioanalysis. The limits of quantification and detection are 0.03 and 0.01 ng L-1 respectively.
Non-specific toxicity was quantified with the Microtox assay, which is based on the bioluminescence inhibition of the marine bacterium Vibrio fischeri. The Microtox assay was selected to obtain a measure of the sum of all TrOCs in a water sample, as it responds rather non-specifically to all chemicals, and to estimate which fraction of the observed toxicity was elicited by the quantified compounds. Water samples were cleaned and enriched by solid phase extraction (Macova et al., 2010). While solid phase extraction does not capture very hydrophilic/polar and volatile compounds, those are not expected to contribute substantially to the mixture toxicity (Escher et al., 2008). Bioassays were expressed as baseline-toxicity equivalent concentrations (baseline-TEQbio) according to Escher et al. (2008), and compared to the predicted toxicity of the quantified TrOCs (baseline-TEQchem). The latter was calculated from the measured concentrations and the relative potencies of the chemicals using a hydrophobicitybased prediction model (Vermeirssen et al., 2010).
In the three plants, ozonation achieved TrOCs removal to a degree depending on the compounds and the ozone dose. The compounds can be divided into two groups: some compounds were effectively removed in all plants regardless of the ozone dose, while the removal of others was lower and generally depended on the ozone dose (Figure 3). It is clear that increasing the specific ozone dose leads to increasing removal, particularly for compounds that show lower removal. In ozonation processes, organic compounds can be oxidised via two mechanisms: reaction with molecular
RESULTS AND DISCUSSION WATER QUALITY BEFORE OZONATION The quality of the treated effluents before the ozonation stage was similar in all the plants (Table 1). The DOC and nutrient levels were low, showing the effectiveness of the WWTPs in removing these pollutants. However, 35 out of the 41
Figure 1. Treatment trains of the investigated full-scale reclamation plants and sampling points (EP = equivalent population; WWTP = wastewater treatment plant; BAC = biological activated carbon filter, MF = microfiltration).
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Technical Features hydrochlorothiazide and caffeine have been shown to react slowly with molecular ozone. More than 87% reduction of estrogenicity expressed as EEQ was observed in the ozonation stage of all the reclamation plants. Even at the lowest dose of 0.2 to 0.3 mgO3 mgDOC-1, high removal of estrogenicity was achieved. This is consistent with previous findings showing that ozonation is a very effective treatment for the reduction of estrogenic activity of treated Figure 2. Removal of dissolved organic carbon wastewater even at relatively low (DOC), baseline-toxicity equivalent concentrations ozone doses. Indeed, several (baseline-TEQbio and baseline-TEQchem) and estradiol equivalent concentration (EEQ) compared to levels estrogenic compounds are very before ozonation (average of three independent reactive with molecular ozone samples ± standard deviation). No error bar means and it has been suggested that the values were below the limit of quantification; the removal is therefore a minimum observed. the transformation products lose most of their estrogenic ozone and reaction with hydroxyl radicals potential. This finding can be rationalised generated by ozone decomposition in by the fact that receptor mediated effects water. Molecular ozone reacts selectively require a good steric fit between the with organic compounds and reaction rates ligand (TrOC or natural) and the receptor. vary over several orders of magnitude. On the contrary, hydroxyl radicals are not Oxidation leads to a dramatic decrease in selective and reaction rates are typically very this interaction and thus to a decrease or high. However, due to a very low hydroxyl complete loss of estrogenic potency. radicals’ concentration, the indirect pathway A decrease of baseline-TEQbio between is not always the dominant one. A review of 31% and 39% was observed after the the literature showed that the compounds ozonation stage in all three plants (Figure that were highly removed independently of 2). This indicates that the mixture of TrOCs, the ozone dose react rapidly with molecular their transformation products and possible ozone and/or have been previously shown formed oxidation by-products have a lower to be easily removed from treated effluents non-specific toxicity compared to the even at low ozone dosage. Among the mixture of parent compounds. Therefore, compounds that showed lower removal there should be no concern regarding a and/or dependency on the ozone dose, metroprolol, diuron, 2,4-D, atenolol, possible increase in non-specific toxicity due
to the generation of oxidation by-products during the ozonation of treated effluents. However, this assay does not take into account the formation of transformation products with specific and reactive modes of toxic action that could still present a hazard to the environment and human health. Specific toxicity is usually receptor mediated and oxidation leads to transformation products that typically have much lower affinity to receptors as shown for estrogenicity. In contrast, reactive intermediates can be formed and there is not enough knowledge on their effect. The reduction of baseline-TEQbio was similar in the three plants and, contrary to what was observed for TrOCs, there was no trend following the ozone dose. The observed reductions were also in a similar range as previous findings on a Swiss WWTP, which indicates that these case studies allow some degree of generalisation (Escher et al., 2009). The baseline-TEQchem in the samples taken before the ozonation step, which were calculated from the relative potencies and concentrations of the TrOCs concentrations, were approximately three orders of magnitude lower than the baseline-TEQbio measured with the bioassays (Table 1). Thus, the quantified TrOCs explain less than 0.3% of the non-specific toxicity. This implies that more than 99.7% of the measured non-specific toxicity is contributed by other compounds present in the water. After ozonation, the fraction of toxicity explained by chemical analysis decreases by a factor of two to four, indicating that either the quantified chemicals were more degradable than the ones not quantified or that the chemicals are just transformed and their toxicity is reduced but not fully eliminated. BIOLOGICAL ACTIVATED CARBON FILTRATION Contrary to the ozonation, BAC filtration significantly removed DOC in the three plants (Figure 2). The removal increased with increasing EBCT, from around 20% in Landsborough (nine minutes) to almost 50% at Gerringong (45 minutes), which is consistent with a biological degradation mechanism.
Figure 3. Removal of selected trace organic chemicals by ozonation (average of three independent samples ± standard deviation). No error bar means the values were below the limit of quantification; the removal is therefore a minimum observed.
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Filtration through biological activated carbon was able to further remove all the remaining compounds after ozonation except perindopril in Landsborough (Figure 4). Removal varied from 0% to more than 99% depending on the compound and the plant. The EBCT seemed to influence the removal; it was higher for the filters with 18 and 45 minutes compared to 9 minutes.
Figure 4. Removal of selected trace organic chemicals by biological activated carbon filters; empty bed contact time is indicated in the legend (average of 3 independent values ± standard deviation). No bar means a removal could not be calculated because concentrations were either too low or below the limit of quantification. Letters in brackets indicate removal generally observed in WWTP estimated from Onesios et al. (2009): P=poor (<20%); I=intermediate (20-80%); G=good (>80%). However, there was no clear increase between 18 and 45 minutes EBCT. Given that the filters have been in use for several years and have filtered many tens of thousands of bed volumes, it is thought that their adsorption capacity is exhausted and they rely only on biological degradation for the removal of organic matter. However, most of the compounds known to be poorly or moderately removed in WWTP were significantly removed in the filters, even with an EBCT as short as 9 minutes. We also previously observed high removal of TrOCs over a period of two years in BAC filters treating non-ozonated and ozonated wastewater. These observations suggest that the bacterial community adapts to the biodegradation of compounds refractory in WWTP as it has been shown in simulated aquifer recharge (Rauch-Williams et al., 2010). But even though it is hypothesised that the adsorption capacity of the activated carbon in the filters is largely exhausted, the removal of specific TrOCs is not correlated with the removal of bulk organic matter and TrOCs breakthrough can be observed much later than DOC breakthrough. Moreover, TrOCs with different properties can show varying breakthrough times separated by tens of thousands of bed volumes. The removal mechanisms of TrOCs in biological activated carbon filters remain unclear at this stage and could be a combination of adsorption and biodegradation, depending on the compounds. The estrogenicity levels were so low after ozonation that it was not possible to accurately assess the effectiveness of BAC
filtration. However, some reduction was observed in all three plants and the levels after BAC filtration were close to or below the quantification limit (0.03 ng L-1). The baseline-TEQbio was further reduced after the BAC filtration by 33±13%, 51±15% and 54±13% compared to after ozonation in Landsborough, Gerringong and Caboolture, respectively. In parallel, the DOC was reduced only by 17±3%, 48±10% and 24±6% respectively, indicating that compounds contributing to the non-specific toxicity are preferentially removed or transformed to metabolites with lower toxic potential.
CONCLUSIONS The investigation of three full-scale reclamation plants using ozonation followed by BAC filtration showed that: I.
The combination of chemical and biological treatment processes can improve treated effluents quality by removing DOC up to 50% and a wide range of TrOCs by more than 90%. It can also reduce non-specific toxicity by up to 70% and estrogenicity by more than 95%;
The non-specific toxicity of the ozonation by-products mixture was 30% to 40% lower than the parent compounds mixture, suggesting that the by-products have a lower toxic potential;
The BAC filtration is capable of further removing some of the TrOCs remaining after ozonation by up to 99% and also reducing the non-specific toxicity of the by-products mixture by up to 54%;
Increasing the ozone dose and filtration EBCT generally has a positive influence on the removal of DOC and TrOCs as well as on the reduction of non-specific toxicity, but there is no direct linear relationship. Therefore, increasing the ozone dose and EBCT further will not necessarily lead to substantive gains in water quality.
In regards to chemical analysis and E-SCREEN assay, ozonation as a single step would be sufficient for the removal of selected TrOCs and reduction of estrogenicity. However, the non-specific toxicity shows us the interest of subsequent BAC filtration because this bioassay integrates the effect of all TrOCs present in the sample. Most transformation products cannot yet be quantified with chemical analysis and, as discussed, will only marginally contribute to estrogenicity, but can still substantially contribute to non-specific toxicity. This is an important point and justifies the parallel application of bioassays when investigating the removal of TrOCs in various wastewater treatment processes. Based on these results, it can be concluded that the combination of ozonation and BAC filtration could be employed to upgrade WWTPs for environmental protection or in water recycling schemes. Placed before high-pressure membrane filtration, it would provide an additional barrier to organic contaminates and would improve the quality of the waste stream. The removal mechanisms of TrOCs in the BAC filters are still unclear. Further research is needed in this area to determine to what extent these compounds are adsorbed and/or biodegraded and if transformation products are formed.
ACKNOWLEDGEMENTS This work was funded by the Urban Water Security Research Alliance under the Enhanced Treatment Project. The National Research Centre for Environmental Toxicology (Entox) is a joint venture of the University of Queensland and Queensland Health Forensic and Scientific Services. The Authors acknowledge the following institutions and individuals who contributed to this study: Unitywater; Veolia Water Australia; Sydney Water Corporation and their staff for providing access to their reclamation plants and help with sampling; and Dr Beatrice Keller and Dr Jelena Radjenovic for their help in establishing the analytical method at the AWMC.
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Technical Features THE AUTHORS Dr Julien Reungoat is a Research Fellow at the Advanced Water Management Centre (AWMC), University of Queensland. Professor Beate I Escher (email: email@example.com. au) is Deputy Director at the National Research Centre for Environmental Toxicology (Entox), University of Queensland. Dr Miroslava Macova was a Postdoctoral Research Fellow at Entox, University of Queensland Dr Wolfgnag Gernjak (email: firstname.lastname@example.org) is a Senior Research Fellow at the AWMC, University of Queensland. Professor Jurg Keller (email: email@example.com) is Director of the AWMC, University of Queensland.
Poulsen A, Chapman H, Leusch F & Escher BI
Escher BI, Bramaz N, Mueller JF, Quayle P, Rutishauser S & Vermeirssen ELM (2008): Toxic Equivalent Concentrations (TEQs) for Baseline Toxicity and Specific Modes of Action as a Tool to Improve Interpretation of Ecotoxicity Testing of Environmental Samples. Journal of Environmental Monitoring, 10(5), pp 612–621.
Rauch-Williams T, Hoppe-Jones C & Drewes JE (2010): The Role of Organic Matter in the Removal of Emerging Trace Organic Chemicals During Managed Aquifer Recharge. Water
Argaud FX, Rattier M, Gernjak W & Keller J (2012): Wastewater Reclamation Using Ozonation Combined With Biological Activated
Macova M, Escher B, Mueller J & Toze S (2010): Bioanalytical Tools to Evaluate Micropollutants Across the Seven Barriers of the Indirect Potable Reuse Scheme. Urban Water Security Research Alliance Technical Report No. 30 (www.urbanwateralliance.org.au/publications/ UWSRA-tr30.pdf). Onesios KM, Yu JT & Bouwer EJ (2009): Biodegradation and Removal of Pharmaceuticals and Personal Care Products in Treatment Systems: A Review. Biodegradation, 20(4), pp 441–466.
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Security Research Alliance, Brisbane.
Reungoat J, Escher BI, Macova M, Farre MJ,
Joss A, Siegrist H & Ternes TA (2008): Are We About to Upgrade Wastewater Treatment for Removing Organic Micropollutants? Water Science & Technology, 57(2), pp 251–255.
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Escher BI, Bramaz N & Ort C (2009): Monitoring the Treatment Efficiency of a Full Scale Ozonation on a Sewage Treatment Plant with a Mode-of-Action Based Test Battery. Journal of Environmental Monitoring, 11(10), pp 1836–1846.
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Carbon Filtration. Urban Water Security Research Alliance Technical Report No. 69. (www.urbanwateralliance.org.au/publications/ UWSRA-tr69.pdf). Reungoat J, Macova M, Carswell S, Escher BI, Mueller JF, Gernjak W & Keller J (2010): Effective Removal of Pathogens and Micropollutants by Ozone and GAC. Water, 37(1), pp 69–72. Vermeirssen ELM, Hollender J, Bramaz N, von der Voet J & Escher BI (2010): Linking Toxicity in Algal and Bacterial Assays with Chemical Analysis in Passive Samplers Exposed to Treated Sewage Effluent. Environmental Toxicology & Chemistry, 29(11), pp 2575–2582.
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AN ASSESSMENT OF ANAMMOX IMPLEMENTATION FOR SIDE-STREAM TREATMENT A case study of the cost effectiveness of implementing Anammox at Sydney Water M Lee, R Ramachandran, D Solley, S Vierboom
ABSTRACT The implementation of Anammox processes for the treatment of ammoniumrich wastewater has received a lot of interest in recent years, and has been successfully implemented in full scale for treatment of side-stream flows arising from dewatering of anaerobically digested sludge. Currently there are many full-scale Wastewater Treatment Plants (WWTPs) around the world that include an Anammox system, including the Dokhaven WWTP at Rotterdam in The Netherlands. Anammox has been associated with substantially reduced carbon and oxygen requirements for nitrogen removal compared to a conventional nitrogen removal process (nitrification-denitrification). This makes Anammox particularly attractive in the treatment of side-stream flows from the dewatering of anaerobically digested sludge. These advantages imply potential to reduce operational costs for nitrogen removal, in particular aeration energy, and methanol dosing costs where an organic carbon source is insufficient.
acceptor and ammonium as the electron donor. The Anammox process is a fully autotrophic nitrogen removal process that utilises a different reaction pathway to a conventional nitrification-denitrification process; it requires less energy and does not require organic carbon. The Anammox process consists of two stages: • Partial nitritation, where ammonium is partially oxidised into nitrite: NH4+ + 1.5O2 g NO2- + H2O + 2H+; and • Anammox, where nitrite reacts with ammonium that is used as the electron donor in lieu of an organic carbon source: NH4+ + NO2- g N2 + 2H2O. Partial nitritation is a process where ammonium is oxidised to nitrite in the presence of oxygen but the oxidation of nitrite to nitrate is prevented by maintaining an environment that is unsuitable for nitrification: low dissolved oxygen and high operating temperature above 25oC.
The Anammox process involves anaerobic oxidation of ammonium using nitrite to form nitrogen gas. This second phase (Anammox) is carried out by a special group of microorganisms, the Planctomycete-like bacteria that combine ammonium and nitrite to produce nitrogen gas in the absence of dissolved oxygen. The Anammox bacteria form a separate and distinct group in the microbial world. The catabolic reactions in the Anammox bacteria take place on a cell internal membrane, whereas such energy generating internal membrane is absent for all other bacteria. The Anammox process is different to conventional nitrogen reduction in the activated sludge process. The conventional nitrogen reduction process involves biological oxidation of ammonium into nitrite and subsequently to nitrate, in the presence of oxygen. The denitrification process involves reduction of nitrate to nitric oxide and nitrous oxide, and subsequently
This paper outlines the assessment of the cost effectiveness of implementation of an Anammox process for treatment of ammonium-rich side-stream flows at Sydney Water’s municipal wastewater treatment plants, with aims to reduce energy use and operating cost. This paper summarises the benefits and relevance of the Anammox process briefly, and then provides a case study of the cost effectiveness of implementing Anammox at Sydney Water. Keywords: Anammox, anaerobic ammonium oxidation, autotrophic, anaerobic digestion, energy saving, nitrogen reduction.
INTRODUCTION Anammox (an acronym for anaerobic ammonium oxidation) is a process whereby an Anammox bacteria converts ammonium directly into nitrogen gas under anaerobic conditions, using nitrite as the electron
Figure 1. Conventional nitrogen removal pathway and Anammox pathway.
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Table 1. Potential Key Benefits of the Annamox Process. Benefits
Reduced oxygen requirement
In comparison to a conventional nitrogen removal process, an Anammox process requires less oxygen for nitrogen removal; reduction in oxygen requirement of up to 60% is achievable based on reported stoichiometric equation, and implies an energy saving for aeration of up to 25%. This potential reduction is due to less oxygen required for partial nitritation in the Anammox process pathway, compared to a conventional nitrogen removal process.
Reduced carbon dosing requirement for nitrogen removal
In comparison to a conventional nitrogen removal process, an Anammox process may reduce organic carbon dosing for removal of nitrogen by up to 100%. An Anammox process pathway typically does not require exogenous electron donor requirements (i.e. organic carbon such as methanol). Implementation of Anammox for treatment of ammonium-rich side-stream flows (e.g. anaerobic digestion centrate) that are returned to the main treatment system can reduce carbon dosing requirements in the main treatment system.
Reduced side-stream flow nitrogen load on main treatment stream
An Anammox process has high ammonium-nitrogen removal efficiency. It can remove up to 90% of ammonium load. This is particularly relevant to treatment of ammonium-rich (up to 1,000 mg/L) centrate or filtrate from anaerobically digested sludge that is returned to the main treatment process. This can result in a subsequent reduction in aeration and carbon dosing requirements in the main treatment stream due to nitrogen load in the returned side-stream flows.
Reduced energy consumption and generation of energy
Reduced biosolids disposal requirements
Benefits from energy consumption reduction and energy generation (biogas) can be obtained via both the Anammox process and associated facilities and modifications required for Anammox implementation. Benefits from associated facilities and modifications include: energy generation from anaerobic digestion (generation of biogas); and elimination of aerobic digestion aeration energy consumption (conversion from aerobic to anaerobic digestion). Anaerobic digestion that is required for Anammox implementation would also result in better digested sludge dewaterability compared to aerobically digested sludge and non-digested sludge. The improvement in dewaterability will result in reduction in dewatered biosolids wet tonnes, and corresponding reduction in biosolids disposal cost.
to nitrogen gas, in the absence of dissolved oxygen and in the presence of soluble organic substance. The Anammox processes are typically applied to ammonium-rich wastewater at elevated temperatures, since it has been determined that the optimum temperature for Anammox activity is in the range of 30°C–40oC. The difference between the conventional nitrogen removal pathway and the Anammox pathway is illustrated in Figure 1. The Anammox process pathway has several advantages over conventional nitrogen removal processes, as described in Table 1. In addition to the benefits that can be realised from the Anammox process itself, there are potential savings achievable in the associated infrastructures from the implementation of Anammox, in particular, anaerobic digestion. The benefits of the Anammox process are mainly associated with no carbon requirement and reduced oxygen requirements for nitrogen removal. These advantages indicate substantial potential to reduce operating costs, in particular energy requirements for aeration and organic carbon dosing for denitrification. This is particularly attractive for wastewater treatment facilities that require substantial
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amounts of carbon dosing to achieve their effluent discharge nitrogen limits, and where ammonium-rich side-stream flows from anaerobic digester centrate are returned back to the main liquid treatment stream. In the context of wastewater treatment, Anammox is generally effective for treatment of flows with low readily biodegradable organic carbon, high ammonium load (500–1,000 mg/L), and elevated temperatures. Centrate or filtrate from dewatering of anaerobically digested sludge generally has these characteristics, which provides a suitable environment for an Anammox process. Although the Anammox process has the potential to be applied more broadly, it has to date only been applied in full scale for treatment of ammonium-rich sidestream flows. It is understood that there are currently no facilities in Australia utilising the Anammox process in full scale.
treatment of side-stream flows, in particular centrate/filtrate from dewatering of anaerobically digested sludge. In this study, Anammox implementation refers to the overall modification required to implement an Anammox system, including modifications to the sludge management and sludge digestion systems.
ASSESSMENT METHODOLOGY Sydney Water owns and operates 26 wastewater treatment facilities that include a combination of both inland and ocean outfall plants. The large pool of potential candidates led to the need for screening to shortlist suitable candidates for assessment on the cost effectiveness of implementing Anammox. The study was carried out in two stages: 1.
Preliminary qualitative screening using a set of screening criteria to shortlist the candidates that were more likely to be suitable for the implementation of an Anammox process; and
Assessment of shortlisted candidates on the cost effectiveness and benefits from Anammox implementation.
ASSESSMENT OBJECTIVES This paper presents the results from a desktop pre-feasibility study on the implementation of the Anammox process at Sydney Water’s wastewater treatment facilities with aims to reduce operating costs and energy consumption. This study forms part of Sydney Water’s energy reduction initiatives. The assessment focused on the
STAGE 1: SCREENING PROCESS Qualitative screening was employed as a qualification process to shortlist plants that may be suitable for Anammox
Table 2. Preliminary Qualitative Screening Criteria. Criteria
Limit on concentration of Total Nitrogen (TN) in the current licence
Description The supernatant from an anaerobic digester and the side-stream flows generated by dewatering anaerobically digested sludge contributes about 5%–10% of the ammonium load to the main liquid treatment process. The Anammox process, if implemented successfully on the side-stream, would significantly reduce (or eliminate) the ammonium load from the side-stream. The TN concentration limits vary for different plants operated by Sydney Water. The impact of ammonium in the side-streams may be substantial when the effluent TN requirement is stringent (low TN concentration values). A TN limit of 10mg/L was used as a cut-off limit in applying this criterion.
Capacity of the wastewater treatment facility
It is considered that the complexity of the Anammox process is not justifiable for small-scale plants due to economic considerations. A plant capacity of 2ML/d (ADWF) was used as a cut-off limit, regardless of whether the plant has existing digestion facilities. Currently, different sludge stabilisation processes are being undertaken at some Sydney Water wastewater treatment facilities. They include: anaerobic and aerobic sludge digestion processes at the larger plants; and sludge lagoon, lime stabilisation, and auto thermal aerobic digestion at the smaller plants. Hence the type of sludge stabilisation employed was also used as an additional basis for exclusion of smaller plants in the shortlisting process; only plants with aerobic or anaerobic digestion processes (larger plants) are considered for shortlisting.
Current use of a sludge digestion process
The aerobic sludge digestion process is an energy intensive process (for aeration), whereas the anaerobic digestion process produces methane gas, an energy source, which may offset heating and mixing energy requirements. An anaerobic digestion system is required to provide the appropriate environment (ammoniumrich flows at elevated temperatures) for Anammox bacteria to thrive. Also, a primary driver of this assessment is to identify potential to increase energy efficiency and reduce operating costs. An assessment of the potential of Anammox implementation supporting a conversion from aerobic digestion to anaerobic digestion was also undertaken as part of this study. The availability of a current sludge digestion process (either aerobic or anaerobic) was used as a qualifying criterion in this screening process.
implementation. The screening process involved a set of simple, objective and robust criteria, as described in Table 2. All three criteria must be met in order to be shortlisted for further assessment. They include: • Limit of concentration of total nitrogen in the current licence; • Capacity of the plant; and • Current use of a sludge digestion process. STAGE 2: ASSESS COST EFFECTIVENESS The sludge treatment processes at the selected plants differ in terms of sludge type, stabilisation process, dewatering method, and management of sidestream flows. The side-stream flows and corresponding ammonium load for the six shortlisted plants were estimated. The cost effectiveness of Anammox implementation was assessed via the following key steps:
• Present value analysis to assess the cost effectiveness of the modifications. Infrastructure requirements and changes to existing operations for Anammox implementation were assessed. For this study, the Anammox process variant was not distinguished and was treated as a “black box”. The assessment methodology on infrastructure requirements for Anammox implementation was based on: • Reuse of existing anaerobic digestion system where available; • Reuse of existing infrastructures and equipment where available and suitable (in particular, flow averaging tanks and sludge thickening and dewatering); • Refurbishment and reuse of existing aerobic digesters that are suitable to be converted into anaerobic digesters; and
• Determine infrastructure requirements and assessment of the capital costs for Anammox implementation;
• Implementing new anaerobic digestion systems where there are no existing anaerobic digestion systems, or where the existing aerobic digesters are deemed unsuitable to be converted into anaerobic digesters.
• Assessment of changes in energy use and annual operating costs (including savings and additional costs); and
The changes to operations (energy, biosolids quantity, operating cost impacts) from the existing system to a modified
system that includes Anammox were also assessed. The key operating parameters included in the assessment were: • Energy recovery from anaerobic digestion (biogas generation); • Energy consumption for heating of anaerobic digesters; • Elimination of aeration energy use for aerobic digestion; • Reduction in biosolids disposal requirements due to better dewaterability of the anaerobically digested sludge; and • Changes in energy and carbon use for nitrogen removal due to the implementation of the Anammox process. Present value analysis was used to determine the cost effectiveness of Anammox implementation. Present value was estimated based on a period of 20 years (years 2012 to 2031) and an annual discount rate of 7%, taking into account the projected load increases and energy costs over this period. The capital expenditure was assumed to be carried out over a period of three years. The renewals and replacement costs were estimated at 30% of the total capital costs every 10 years.
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Table 3. Shortlisted Candidates. Capacity (ML/d)
Total Nitrogen Limit (mg/L)
Current Sludge Digestion
Potential for anaerobic digester to be included in the future
SHORTLISTED CANDIDATES Of the 26 wastewater treatment facilities assessed against the preliminary screening criteria, six treatment facilities were shortlisted, as outlined in Table 3. The sludge digestion system at St Marys was previously an anaerobic digestion process that has been converted to an aerobic digestion process, and the sludge digestion system at Quakers Hill has been decommissioned. Both the digestion system at St Marys and Quakers Hill can be converted back into anaerobic digesters and reused. The existing digesters at Penrith and Rouse Hill were assessed to be unsuitable to be converted into anaerobic digesters and hence new digesters have been proposed. West Hornsby and Hornsby Heights have existing anaerobic digestion systems that can be retained, hence, no modifications would be required. West Hornsby and Hornsby Heights are substantially smaller in capacity than the other shortlisted candidates.
RESULTS AND FINDINGS INFRASTRUCTURE REQUIREMENTS An analysis of the key infrastructure requirements for Anammox implementation was undertaken for the six shortlisted plants.
The study showed that a substantial proportion of the total capital cost required to implement the Anammox process was associated with the provision of an anaerobic digestion system where none is used at present (Quakers Hill, St Marys, Penrith and Rouse Hill). This was found to contribute substantially to the cost of implementation. Figure 2 shows that implementation of anaerobic digestion and auxiliary systems (except for Hornsby Heights and West Hornsby) comprise up to 90% of the estimated total capital cost of implementing the Anammox process; the cost of the Anammox system is relatively small. CHANGES TO OPERATIONS The side-stream flows and potential benefits and costs incurred from Anammox implementation were estimated based on plant data. The projected benefits are outlined in Table 4. Interestingly, the benefits realised from the Anammox process itself (i.e. reduced aeration and methanol requirement for nitrogen removal) are relatively small compared to the indirect benefits realised from the overall modification for Anammox implementation at the plants considered. It was found that further additional benefits can be realised via modifications
for Anammox implementation at St Marys. At St Marys, raw sludge from one treatment train is currently treated in the bioreactor of another train, causing high organic loading and increased aeration requirements. The provision of anaerobic digesters as part of Anammox implementation would allow transfer of the raw sludge to the anaerobic digesters instead of the bioreactor, resulting in potential to reduce aeration energy consumption at the bioreactor from reduced organic overloading, while at the same time increasing energy recovery from anaerobic digestion process due to the introduction of raw sludge with higher organic content. Most of the key parameters assessed would generally result in benefits or savings, with the exception of heating and mixing requirements of the anaerobic digesters and the operating cost of the Anammox system. It is interesting to note that the overall project benefits are predominantly derived from the anaerobic digestion process, that is required as part of the Anammox process implementation. COST EFFECTIVENESS The present costs for Anammox implementation at all six plants assessed were found to be substantial, as shown in Figure 2 and Table 5. The results indicate that Anammox implementation at these plants is not currently financially attractive.
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Anammox system cost -4
Anaerobic digestion system cost new/refurbish
Figure 2. Key cost parameters.
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Total capital cost including Anammox
Replacement and Annual change in renewals ($/10years) operating cost ($/year)
Present cost (2012)
Key Parameters Assessed Penrith
Implementation of an anaerobic digestion system (St Marys, Quakers Hill, Penrith and Rouse Hill) represents a large capital cost component for Anammox implementation. This study found that the availability and ease of implementation of an anaerobic digestion system would significantly affect the capital cost requirements and corresponding cost effectiveness of Anammox implementation. The existing process configuration could also affect the cost effectiveness of Anammox implementation.
Some considerations include the type of sludge (digestion of raw sludge would generally result in higher biogas generation compared to digestion of long sludge age waste activated sludge), better dewaterability of the digested sludge (anaerobically digested sludge is generally easier to dewater than aerobically digested sludge), and conversion from aerobic digesters to anaerobic digesters (elimination of aeration energy requirements). West Hornsby and Hornsby Heights have existing anaerobic digestion systems, hence, would require relatively lower capital costs for Anammox implementation. However, the size of operations of these two plants is small; they do not have the economies of scale to realise sufficient savings to offset the cost of installing a new Anammox system. The effect of “economies of scale” is indicated by the decreasing trend of unit capital costs and unit operating costs for an Anammox system as the side-stream ammonium load (size of Anammox system) increases (see Table 5). In comparison, the Anammox system at Dokhaven WWTP in Rotterdam (The Netherlands) treats an ammonium load of 500kg/d, compared to a potential 201kg/d, 67kg/d and 35kg/d at St Marys, West Hornsby and Hornsby Heights respectively.
Table 4. Benefits and Costs. Benefits/Costs
Benefits Biogas generation
Aerobic digestion aeration offset
Reduction in biosolids (wet tonnes) quantity
Reduction in aeration requirement at main system by reducing sidestream ammonium return
Reduced carbon requirement at main system by reducing sidestream ammonium return
Reduced organic overloading of main treatment bioreactor1
Anaerobic digesters heating
Increased aeration requirement at main system due to increase in side-stream ammonium return
Increased carbon requirement at main system due to increase in side-stream ammonium return
Notes: “ü” denotes Benefit/Saving, “O” denotes Additional Cost, “±” denotes No Change, “–” denotes Not Applicable. Most of the plants assessed (except for Hornsby Heights) do not currently treat their side stream flows, hence the implementation of Anammox and return of side stream flows to the main treatment system would result in net introduction of ammonium to the main treatment stream and subsequently increase carbon and aeration requirements. 1 An opportunity to reduce organic loading (and hence aeration requirements) at St Marys main treatment stream was identified.
Table 5. Summary of Assessment. St Marys
Side-stream flows (kL/d)
Side-stream flows ammonium load (kg/d)
Cost of anammox system ($ million)
Total capital cost including an Anammox system ($ million)
Key Assessment Parameters
Change in annual operating cost ($ million)
Change in annual energy use (MWh)
Change in biosolids wet tonnes (t/yr)
Unit capital cost for an Anammox system ($ thousand/(kgNH4-N/d))
Unit operating cost for an Anammox system ($/kgNH4-N/d)
Present cost ($ million, 7% discount rate, yr 2012)
Notes: Negative values denote savings and positive values denote costs. The capital costs of the Anammox system were estimated based on budget pricing information from technology suppliers. The operating costs of the Anammox system were established based on a combination of information from technology suppliers and estimation from first principles; they cover the main cost items of energy consumption (mixing, aeration, and heating) and chemical dosing (caustic). The “Unit Capital Costs” and “Unit Operating Costs” for the Anammox systems refers to the Anammox bioreactor system only, and do not include costs incurred for provision of auxiliary facilities. The decreasing costs of the system as the capacity of the system increases provides an indication of economies of scale.
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Technical Features CONCLUSION
The implementation of an Anammox process requires two main components: an anaerobic digestion system, and associated Anammox facilities. For the larger plants considered (Quakers Hill, St Marys, Penrith and Rouse Hill), a large proportion of capital costs were associated with the provision of anaerobic digestion systems. For West Hornsby and Hornsby Heights, the plants were not large enough to realise sufficient benefits to offset the implementation costs. The present costs for all six plants assessed were found to be substantial, which indicates that Anammox implementation at these plants is not currently financially attractive. In the context of the larger plants assessed, should required modifications be potentially driven from other aspects of plant operations, the capital cost required would be reduced and this would improve the attractiveness of Anammox implementation. The study found that the cost effectiveness of Anammox implementation for treatment of ammonium-rich side-stream flows does not solely depend on the benefits of the Anammox process, as it is also significantly influenced by external factors and required modifications. Factors that must be considered when assessing the cost effectiveness of Anammox implementation include: • Suitability of the plant (existing process units and configuration); • Availability/ease of implementation of an anaerobic digestion system; and • Size of the plant (economies of scale). The study found that a wastewater treatment plant that has a sufficiently large scale of operation and an existing anaerobic digestion system is more likely to be an attractive candidate for Anammox implementation.
ACKNOWLEDGEMENTS The Authors would like to thank Sydney Water staff for their support and commissioning this study. The Authors would also like to recognise the contributions made by the Anammox technology suppliers in establishing specific requirements and cost estimates for their proprietary Anammox systems.
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Ming Wei Lee (email: firstname.lastname@example.org) is a Process Engineer at GHD with a focus on water and wastewater treatment, water recycling, integrated water management, water and energy efficiency, and process optimisation. Rama Ramachandran (email: rama. email@example.com) is a Process Engineer at GHD with extensive experience in strategic and detailed planning of upgrades and amplification of sewage treatment and effluent management facilities. David Solley (email: firstname.lastname@example.org) is a Process Engineer at GHD with a broad range of experience in water and wastewater treatment, covering nutrient removal for municipal and high strength wastewater, water recycling processes, and biosolids treatment. Sarah Vierboom (email: sarah.vierboom@ sydneywater.com.au) is a Project Manager at Sydney Water with a focus on water and energy futures.
REFERENCES Ahn Y (2006): Sustainable Nitrogen Elimination Biotechnologies: A Review, Process Biochemistry, 41, pp 1709–1721. Bolzonella D, Pavan P, Battistoni P & Cecchi F (2005): Mesophilic Anaerobic Digestion of Waste Activated Sludge: Influence of the Solid Retention Time in the Wastewater Treatment Process, Process Biochemistry, 40, pp 1453–1460. Cervantes FJ, De la Rosa DA & Gomez J (2001): Nitrogen Removal from Wastewaters at Low C/N Ratios with Ammonium and Acetate as Electron Donors, Bioresource Technology, 79, pp 165–170. Chen T, Zheng P, Tang C, Wang S & Ding S (2011): Performance of ANAMMOX-EGSB Reactor, Desalination, 278, pp 281–287. Daigger GT, Sanjines P, Pallansch K, Sizemore J & Wett B (2011): Implementation of a Full Sale Anammox-Based Facility to Treat an Anaerobic Digestion Sidestream at the Alexandria Sanitation Authority Water Resource Facility, IWA Publishing 2011, Water Practice & Technology, Vol 6, No 2, doi: 10.2166/ wpt.2011.033. Dapena-Mora A, Campos JL, Mosquera-Corral AM, Jetten MSM & Mendez R (2003): Stability of the ANAMMOX Process in a Gas-Lift Reactor
and a SBR, Journal of Biotechnology, 110, pp 159–170. Isaka K, Sumino T & Tsuneda S (2007): High Nitrogen Removal Performance at Moderately Low Temperature Utilizing Anaerobic Ammonium Oxidation Reactions, Journal of Bioscience and Bioengineering, 103, 5, pp 486–490, doi: 10.1263/jjb.103.486. Jardin N & Hennerkes J (2011): Full Scale Experience with the Deammonification Process to Treat High Strength Sludge Water – A Case Study, 11th IWA Specialised Conference on Design, Operation and Economics of Large Wastewater Treatment Plants, 4–8 September, 2011, Budapest, Hungary. Jardin N & Hennerkes J (2012): Full-scale Experience with the Deammonification Process to Treat High Strength Sludge Water – A Case Study, Water Science and Technology, 65, 3, pp 447–455. Jetten MSM, Wagner M, Fuerst J, van Loosdrecht M, Kuenen G & Strous M (2001): Microbiology and Application of the Anaerobic Ammonium Oxidation (‘Anammox’) Process, Current Opinion in Biotechnology, 12, pp 283–288. Li H, Zhou S, Ma W, Huang G & Xu B (2012): Fast Start-up of ANAMMOX Reactor: Operational Strategy and Some Characteristics as Indicators of Reactor Performance, Desalination, 286, pp 436–441. Mulder JW, Duin JOJ, Goverde J, Poiesz WG, van Veldhuizen HM, van Kempen R & Roeleveld P (2006): Full Scale Experience with the SHARON Process Through the Eyes of the Operators, Proceedings of the Water Environment Federation, WEFTEC 2006. Padin JRV, Pozo MJ, Jarpa M, Figueroa M, Franco A, Corral AM, Campos JL & Mendez R (2009): Treatment of Anaerobic Sludge Digester Effluents by the CANON Process in an Air Pulsing SBR, Journal of Hazardous Materials, 166, pp 336–341. Padin JV, Mosquera-Corral A, Campos JL, Mendez R, Revsbech NP (2010): Microbial Community Distribution and Activity Dynamics of Granular Biomass in a CANON Reactor, Water Research, 44, pp 4359–4370. van Dongen U, Jetten MSM & van Loosdrecht MCM (2001): The SHARON®-Anammox® Process for Treatment of Ammonium Rich Wastewater, Water Science and Technology, 44, 1, pp 153–160. Van Hulle SWH, Vandeweyer HJP, Meesschaert BD, Vanrolleghem PA, Dejans P & Dumoulin A (2010): Engineering Aspects and Practical Application of Autotrophic Nitrogen Removal from Nitrogen Rich Streams, Chemical Engineering Journal, 162, pp 1–20. Wang T, Zhang H, Gao D, Yang F, Yang S, Jiang T & Zhang G (2011): Enrichment of Anammox Bacteria in Seed Sludges from Different Wastewater Treating Processes and Start-up of Anammox Process, Desalination 271, pp 193–198.
IMPACT OF SHORT-TERM TEMPERATURE CHANGES ON ANAEROBIC DIGESTER PERFORMANCE Temperature differentials of up to 6°C can be applied for the purposes of recirculation loop heating of digesters DJ Batstone, PD Jensen ABSTRACT Digester heating is often done on digester liquid through an external loop in order to take advantage of the lower viscosity of digestate compared with feed. However, in this configuration having a high temperature differential between digestate in the heat exchanger inlet and digestate in the outlet (ΔTc ) is critical. This minimises recirculation rates, pump and pipe sizes and, hence, decreases capital costs. A value of 2°C has been used in the past, but increasing this to 6°C would substantially decrease costs. In this paper, we test 2°C, 6°C, and 10°C in a 55°C 1L digester (10-day retention) fed with mixed activated and primary sludge. Overall performance was good, with a VS destruction of 60% and stable organic acids <500 mgCOD L-1. No response was observed to a ΔTc of 6°C. However, both performance (VS destruction) and stability (as organic acids) showed a strong response (VS destruction to 30%, organic acids to >1500 mgCOD L-1) when the ΔTc was changed to 10°C. Organic acids recovered within 10 days, while VS destruction recovered within 18 days while maintaining the ΔTc at 10°C. Therefore, while 6°C appears safe, 10°C may also be used with some acclimatisation required.
INTRODUCTION Anaerobic digesters must operate at elevated temperatures compared to ambient, with mesophilic digesters operating between 33°C and 40°C, and thermophilic digesters operating at >50°C (Batstone and Jensen, 2011). This means material needs to be either heated as it enters the digester (heating raw primary or activated sludge), or a heated recirculation loop needs to be heated continuously.
Traditional practice is to heat incoming material. However, this has a number of disadvantages: a.
Feed material has a higher concentration and viscosity compared to digestate (Baudez, Markis et al., 2011). This means that there is a higher pressure drop across the heat exchanger, and can also induce changes from turbulent to intermediate, or even laminar flow regimes (Eshtiaghi, Markis et al., 2012), with a consequent loss in heat transfer coefficient (U) and, hence, transfer efficiency. As digester temperatures have increased together with the increase in application of high-temperature thermophilic and temperature-phased anaerobic digestion systems (TPAD) (Carrère, Dumas et al., 2010), the possibility of heat exchanger caking and fouling has increased, particularly for higher concentration feed materials.
Because of this, particularly where hydraulic recirculation mixing is used, feed concentrations are high, or where the reactor is a high-temperature digester, in-line recirculation heating is a favoured option. One parameter critical to the design of recirculation heating is the sludgeside ΔTs. The energy transfer per pass is directly related to the inlet-outlet sludge temperature differential. Operating at a lower temperature differential means that a much higher recirculation sludge flow is required, with consequent increased capital and operating costs. The standard industryapplied maximum ΔTs allowed is 2°C (Griffith, 2012), but particularly where hightemperature processes are to be used, this applies an unreasonable recirculation rate purely due to ΔTs requirements. Normally, recirculation rates should be the minimum
required to achieve mixing. Operating at a higher ΔTs such as 6°C would allow onethird of the flow and significant savings in terms of energy and capital costs. The main negative impact is, potentially, loss in activity of the methanogenic community. However, no literature references were found on the impact of very short-term (seconds-minutes) temperature changes on methanogens. There has been extensive work done on the impact of long-term stable operating temperature (Siegrist, Vogt et al., 2002), and it is known that ramp rates during startup should be maintained below 2°C (Batstone and Jensen, 2011), and that shortterm increases at high temperature (>90°C) will kill pathogens and methanogens (Paul, Carrère et al., 2012), but there has been no work on the impact of moderate temperature increases over short time frames. Research work here (in a continuous reactor) is required to avoid excessive unnecessary capital investment. In this paper we evaluate the impact of short-term temperature increases in a laboratory scale activated and primary sludge digestion system.
METHODS The experimental work is based around a 1L thermophilic (55°C) laboratory scale reactor, fed with a mixture of primary and activated sludge (70%/30% by VS), sourced from the Elanora Wastewater Treatment Plant at Elanora in Queensland). After stabilisation at 2°C ΔTs over 25 days, the system was stepped to 6°C ΔTs. It was then operated at 6°C ΔTs for 40 days, after which there was a leak in the recirculation line causing reactor failure. Since then, it has been restabilised and characterised again at 2ºC ΔTs (40 days) after a 40-day restart period. Data collected during the restart was lost in a freezer accident. Operation was, therefore, in three major blocks:
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Technical Features respectively need to be used. It is appropriate for the assessment here.
Coil (30 seconds)
Another way of assessing VS destruction is using the van Kleeck VS calculation, which is based on VS fraction:
Pump Water bath (57°C - 65°C) TI
Digester (1L) 55°C
Figure 1. Reactor set-up used to assess thermal shock. a.
Initial operation at 2°C ΔT (25 days)
Subsequent operation at 6ºC ΔT (40 days)
Restart at 2°C ΔT (40 days)
Stable operation at 2°C ΔT (40 days)
Final stable operation at 10°C ΔT
+ ΔTs through the whole loop throughout the trial. The system was operated with a nominal retention time of 10 days.
The system was inoculated from the second stage of a laboratory scale temperature-phased anaerobic digestion process. Feed solids was approximately 2.5% total solids; 2% volatile solids.
A diagram of the laboratory reactor is shown
SAMPLING AND ANALYSIS
in Figure 1. The key elements were:
Samples were taken from the recirculation line or through a dedicated reactor port three times per week. Gas was collected in a gas bag, and accumulated gas measured by GC-TCD (Perkin-Elmer), with flow being measured by liquid displacement in a manometer five times per week.
A 1L glass jacketed reactor, fitted with pH and temperature probes;
Gas bag to collect daily gas (not shown in Figure 1);
Peristaltic feed pump;
Water bath operated at 55°C to maintain
heat exchange coil, and an extended,
Liquids were analysed for VS/TS by standard methods (Franson, Eaton et al., 2005), and total COD by Merck Cell tests (Cell test 14555). VFAs (acetate, propionate, iso-butyrate, butyrate, iso-valerate, valerate, hexanoate) were measured by another PerkinElmer GC with a flame ionisation detector (FID), as described in Ge (Ge, Jensen et al., 2010). Ammonia and TKN were analysed by digestion followed by flow injection analysis as described in standard methods (Franson, Eaton et al., 2005).
insulated return pipe to ensure retention
reactor at this temperature; e.
Water bath operated at 55°C + ΔT to assess impact of the short-term heat exchange;
Recirculation circuit through the higher temperature water bath, including a peristaltic feed pump, 316 stainless steel
time of approximately 30 seconds at elevated temperature. This approach was considered to be typical of full-scale operation; g.
Thermocouples were placed in the reactor, at the inlet to the bath, outlet from the bath, and just prior to the reactor. These thermocouples were used to ensure that the temperature was 55°C
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VS destruction was calculated on two different measures; mass balance VS destruction:
VS conc ,in
VS conc ,out
VS conc ,in
Where VSDMB is the mass balance based VS destruction. It assumes that either flow or VSconc,in is relatively stable, and that the system is at steady state. If these conditions cannot be met, a flow weighted input or dynamic model
VS frac ,in VS frac ,in
VS frac ,out
VS frac ,in .VS frac ,out
Where VSDVK is the van Kleeck VS destruction, VSfrac,in is the fraction of solids that is volatile in the influent, and VSfrac,out is the fraction of solids that is volatile in the outlet. This measure uses mineral solids fraction as an assumed stable reference. Therefore, if mineral solids accumulate in the reactor, it will be in error. The reason that both measures are used is that both are susceptible to different potential issues. VSDMB can be susceptible to sampling errors, while VSDVK can be susceptible to accumulation, loss, or formation of mineral solids in the digester. MODEL-BASED ANALYSIS The IWA ADM1 (Batstone, Keller et al., 2002) is a standardised model of anaerobic processes that represents performance of comparable digesters. It can also be used to objectively assess rate controlling steps such as hydrolysis. Once the basic parameters are set, deviation below model predictions indicates the real process is underperforming against the benchmark and vice-versa. The IWA ADM1 was implemented at a temperature of 55ºC in single stage configuration with a single main feed, with feed characterisation using the input model of Nopens (Nopens, Batstone et al., 2009) for the purposes as noted below.
RESULTS AND DISCUSSION STABILITY The main measure of stability is organic acid concentrations as shown in Figure 2. This indicates that acetate relatively quickly dropped to approximately 100 mgCOD L-1, and remained there for most of the operational period except brief periods at ΔT=10°C. Total VFA remained elevated for a longer period (due to propionate), but also dropped within 40 days. During ΔT=6°C, absolutely no impact of the increased ΔT could be observed. ΔT=10°C may have induced a brief period of increased total VFA (mainly propionate), but the system quickly stabilised at a VFA level of <500 mgCOD L-1, which is very good for a thermophilic reactor. pH and gas composition (gas composition is shown in Figure 3) were stable and consistent over the 170 days. Methane composition is slightly low due to the elevated temperature in the reactor (55ºC).
Figure 2. Organic acid concentrations, including total VFA (x) and acetate only ( ).
Figure 3. CH4 composition over the whole period.
Figure 4. Actual (x) and modelled (-) van Kleeck VS destruction.
Figure 5. Actual (x) and modelled (-) mass balance VS destruction.
90% 80% 70% 60% 50% 40% 30% 20%
conditions rather than a change in digester performance. There was a definite, though temporary, drop in performance when switching to a deltaT of 10°C. It rapidly recovered within 10 days.
Model based analysis indicated 0% that all periods were All Data MB All Data VK 2C_1 VK 6C VK 2C_2 VK 10C_VK statistically comparable Figure 6. Apparent degradability (measure of digester except the final period performance). (10°C_VK), where an DIGESTER PERFORMANCE average drop of 15% in apparent VS destruction was observed Performance was assessed on the basis of (Figure 6). The inherent characteristics (i.e., two measures – van Kleeck VS destruction, degradability) do not change during the as previously described (VK), and apparent different periods except during the 10-day VS destruction on mass balance (MB). The modelled and actual VK VS destruction is period, and the model indicated this was shown in Figure 4, while the modelled and due to a drop in hydrolysis rate rather than actual MB VS destruction is shown in Figure material degradability, likely indicating that 5. The van Kleeck VS destruction is relatively the underlying hydrolytic performance consistent over the whole period, while the decreased in this period. mass balance VS destruction is inconsistent ANALYSIS in the last period. Good agreement between There was no response at ΔT=6°C, and model and data points indicate that inherent a substantial (though momentary) loss of performance characteristics were similar performance at ΔT=10°C. The response (i.e., hydrolysis rate, extent), and that drops could be seen as instability (measured as or increases in performance were largely acetate and propionate release), and a related to feed changes or non-steady state 10%
decrease in performance (measured as a drop in VS destruction). The drop was both significant and substantial. VS destruction is a measure of hydrolysis performance, while organic acid instability is a measure of methanogenic performance (Batstone and Jensen, 2011). These two could have been either independently influenced, or the increased organic acids could have induced a decrease in hydrolytic performance, which is known to occur with pure substrates (Martinelle, 1994). In this case, however, poor van Kleeck VS destruction (which normally responds quickly when inhibitors are removed) persisted for almost one week after the organic acids dropped to background levels, indicating that both processes were influenced by the temperature change. The rapid acclimatisation (over three weeks) indicates that at least at this level, the community were able to quickly adapt to the slightly unusual condition. It is unknown whether this change was driven by a substantial change in community composition, or adaptation of the microbes present. This could be addressed in the future through 16s Pyrotag community analysis if necessary for additional application at higher ΔT levels. Overall, however, it is unlikely that such high ΔT levels will be required, since both the existing and subsequent designs have been mixing and heat exchanger limited
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Technical Features above ΔT=6°C, and 6°C is substantially better than 2°C in terms of decreased capital and operating costs.
CONCLUSIONS Digester operation indicated no response in terms of stability or performance (VS destruction) in response to a ΔT of 6°C compared to a ΔT of 2°C. However, a 10°C induced instability and a loss of performance. Recovery occurred within 20 days while maintaining a 10°C ΔT.
ACKNOWLEDGEMENTS This research was funded by South East Water Ltd as part of the Mt Martha Process Upgrade. We thank Terry Anderson from South East Water for his contributions in planning and critical review of the work.
THE AUTHORS Damien Batstone (email: email@example.com. au) is an Australian Research Fellow at the Advanced Water Management Centre (AWMC), The University of Queensland, and is joint leader of the Anaerobic Biotechnology and Nutrient Recovery research groups.
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Paul Jensen (email: p.jensen@ awmc.uq.edu.au) is an AMPC/ MLA Research Fellow and AWA Queensland YWP of the Year. He is joint leader of the Anaerobic Biotechnology Research Program at AWMC.
REFERENCES Batstone DJ & Jensen PD (2011): 4.17 – Anaerobic Processes. In: Editor-in-Chief: Peter W, editor. Treatise on Water Science. Oxford: Elsevier, pp 615–639. Batstone DJ, Keller J, Angelidaki I, Kalyuzhnyi SV, Pavlostathis SG, Rozzi A, Sanders WTM, Siegrist H & Vavilin VA (2002): Anaerobic Digestion Model No. 1 (ADM1), IWA Task Group for Mathematical Modelling of Anaerobic Digestion Processes. London, IWA Publishing. Baudez JC, Markis F, Eshtiaghi N & Slatter P (2011): The Rheological Behaviour of Anaerobic Digested Sludge. Water Research, 45(17), pp 5675–5680. Carrère H, Dumas C, Battimelli A, Batstone DJ, Delgenès JP, Steyer JP & Ferrer I (2010): Pretreatment Methods to Improve Sludge Anaerobic Degradability: A Review. Journal of Hazardous Materials, 183(1-3), pp 1–15. Eshtiaghi N, Markis F & Slatter P (2012): The Laminar/ Turbulent Transition in a Sludge Pipeline. Water Science and Technology, 65(4), pp 697–702.
Franson MAH, Eaton AD, Association. APHA, AWWA Federation. WE. (2005): Standard Methods for the Examination of Water & Wastewater. Washington, DC: American Public Health Association. Ge H, Jensen PD & Batstone DJ (2010): Pretreatment Mechanisms During ThermophilicMesophilic Temperature Phased Anaerobic Digestion of Primary Sludge. Water Research, 44(1), pp 123–130. Martinelle M & Hult K (1994): Kinetics of Triglyceride Lipases. In: Woolley P, Petersen, S, editor. Lipases. Cambridge, Cambridge University Press, p 363. Nopens I, Batstone DJ, Copp JB, Jeppsson U, Volcke E, Alex J & Vanrolleghem PA (2009): An ASM/ADM Model Interface for Dynamic Plantwide Simulation. Water Research, 43(7), pp 1913–1923. Paul E, Carrère H & Batstone DJ (2012): Thermal Methods to Enhance Biological Treatment Processes. Biological Sludge Minimization and Biomaterials/Bioenergy Recovery Technologies, John Wiley & Sons Inc., pp 373–404. Siegrist H, Vogt D, Garcia-Heras J & Gujer W (2002): Mathematical Model for Meso and Thermophilic Anaerobic Sewage Sludge Digestion. Environmental Science & Technology, 36(5), pp 1113–1123.
ONSITE AND DECENTRALISED WASTEWATER SYSTEMS Advances from a decade of research and educational efforts RL Siegrist, JE McCray, KS Lowe, TY Cath, J Munakata-Marr
These systems have evolved to include an array of devices and technologies that can be assembled to achieve varied discharge or resource recovery and recycling objectives. New mathematical models and decision support tools enable proper system selection and design for a particular application. To achieve needed advances in the science and engineering of onsite and decentralised systems and help assure integration of the outcomes into practice, research and educational efforts have been essential.
INTRODUCTION In the US today, most people have ready access to safe drinking water and adequate sanitation as a result of major investments during the 20th century. The situation is similar in many other industrialised nations around the world. As we entered the 21st century, centralised water treatment plants and piping networks produced and distributed drinking water while sewers collected wastewater for treatment at remote plants. In the US, centralised water and wastewater systems were serving about 85% and 75% of the population, respectively. However, there were growing concerns about the sustainability of large centralised systems. In the US, many of the components of large centralised systems were at or approaching the end of their design life spans and rehabilitation options were often limited and extremely costly. In addition, some of the potential flaws in centralised systems were becoming more apparent. For example, nearly 50% of the safe drinking water produced is typically wasted as a result of water distribution losses (~20%) and clean water use for flushing toilets (~30%).
Centralised systems can also lead to unplanned urban sprawl, localised water resource depletion, excess consumption of chemicals and energy, release of untreated sewage through leaking sewers and sewer overflows, and barriers to beneficial recycling and reuse. As evidenced by recent events in the US and abroad, centralised systems are also subject to upsets during natural disasters and may be targets of terrorist activities. In contrast to the larger centralised systems established in urban areas, private wells and septic systems were commonly used in rural and suburban areas. During much of the 20th century, many viewed these systems as temporary with a vision that, sooner or later, they would be replaced by connection to centralised systems as these systems were expanded across the US. During this period, onsite and decentralised wastewater systems were not designed or implemented to achieve explicit treatment and reuse objectives over long-term permanent use. Not surprisingly, such systems suffered performance deficiencies ranging from hydraulic failures to localised contamination of groundwaters and surface waters. These deficiencies were attributed to varied causes including poor system siting, improper design, faulty installation, and/or inadequate operation and maintenance. To support a growing vision that onsite and decentralised systems were not temporary, but rather were a permanent component of a sustainable wastewater infrastructure, research and educational initiatives, along with changes in regulatory requirements, sought to improve the standard of practice and mitigate many of the past performance deficiencies (eg, USEPA, 1997; Siegrist, 2001). Based on research and development efforts over the past decade or more, modern onsite and decentralised systems have evolved to include a growing array of approaches, devices and technologies that can be applied at the development level up to watershed scale. Ultra low-demand fixtures or source separation plumbing can
enhance water infrastructure by minimising water demands and maximising reuse in buildings and developments spanning rural, peri-urban and urban areas. Treatment can be achieved using anaerobic and aerobic bioreactors, porous media biofilters, sorbent filters, membrane separation units, constructed wetlands, soil treatment units, UV disinfection units and other technologies. Reuse of reclaimed water can occur through toilet flushing, landscape irrigation and other applications. The vision of onsite and decentralised systems is still unfolding and the possibilities for the future are openended. One vision is that as planning and design of sustainable water and wastewater infrastructure occurs, onsite and decentralised systems will be universally and equitably considered across all scales of development (e.g., individual buildings, cluster developments, communities, watersheds). Any automatic predisposition towards more centralised infrastructure will have vanished. Modern infrastructure will be characterised by low-demand plumbing systems, treatment of wastewater at or near the point of generation, reclamation and reuse of wastewater resources, use of sensors and monitoring devices to verify and enhance performance, and remote process control and system management to monitor and automatically correct any system malfunction. Systems will commonly mimic natural processes to achieve performance objectives while minimising water, energy and chemical use, and enabling beneficial reuse.
A DECADE OF RESEARCH AND EDUCATIONAL EFFORTS Among the research and educational efforts initiated in the US during the 1990s, the Small Flows Program was established at the Colorado School of Mines (CSM) in Golden, Colorado. Highlights of some of the research and educational activities carried out over the past decade are presented here.
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Throughout the United States and worldwide, solutions to wastewater infrastructure need to be effective in protecting public health and preserving water quality while also being acceptable, affordable and sustainable. Onsite and decentralised systems have the potential to achieve these goals in rural areas, periurban developments, small towns and urban centres in larger cities.
Table 1. Average daily wastewater flow rates from residential dwellings based on field monitoring by Lowe et al. (2009) compared to overall averages of two earlier studies. Study average flow (L/day/person)
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Reference and study characteristics
Lowe et al. (2009) – Building sewer flows measured at each of 17 houses in Colorado, Minnesota and Florida, US, in 2008–09
Mayer et al. (1999) – Indoor water usage measured at each of 1,188 houses in 12 cities in Colorado, California, Oregon, Washington, Arizona, Florida, US and Ontario, Canada in the 1990s
USEPA (1980) – Based on multiple studies of water use or wastewater flows conducted by different investigators during the 1960s and 1970s
Table 2. Typical domestic wastewater composition determined by Lowe et al. (2009) and reported in two other published sources that are commonly used for onsite system design. Lowe et al. (2009)
Crites & Tchobanoglous (1998)
Oil & grease
Research Highlights Several areas have been the focus of sustained research activities, including projects to: 1) determine the flow and composition of modern onsite wastewater streams; 2) evaluate the performance dynamics of bioreactors and biofilters, including their integration with soil-based unit operations; 3) evaluate the performance of decentralised systems utilising membrane
bioreactors; and 4) develop mathematical models and decision support tools. A short discussion also highlights considerations important to achieving performance potential when systems are implemented under normal field conditions.
Characterising Flow and Composition of Onsite Wastewaters Quantitative understanding of water use and wastewater characteristics is important for proper system selection and design. Until recently much of the available characterisation data were from studies completed more than 20 years ago. Recent and ongoing CSM research projects have been focused on advanced characterisation of modern waste streams. For example, Figure 1. Cumulative frequency distribution of total in one recent CSM phosphorus loading rates based on wastewater monitoring at 17 residential dwellings in Colorado, Florida, and Minnesota, project, over 150 which included 24-hour flow-weighted composite sampling literature sources were during each season (2008–2009) (Lowe et al., 2009).
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analysed to obtain characterisation data for conventional constituents, microorganisms and trace organic compounds in raw wastewater and septic tank effluent (STE) from domestic (single and multiple), food, medical and non-medical sources (Lowe et al., 2006). Field monitoring was then completed at 17 domestic sites in three regions of the US (Lowe et al., 2009). A specialised apparatus was fabricated to collect 24-hour composite samples of raw wastewater and STE during each season of the year. Analyses were made for a suite of wastewater parameters (e.g., flow, temperature, pH, cBOD5, nutrients, microorganisms, and trace organic compounds). Example results are presented in Tables 1 and 2 and in Figure 1. Characterisation data for trace organic compounds have also been obtained through field monitoring at 30 sites in Colorado (Conn et al., 2006) in addition to the 17 sites studied by Lowe et al. (2009). This research revealed that many organic compounds could be present in wastewaters at relatively low but potentially important concentrations. Organic compounds associated with consumer product chemicals (e.g., caffeine, nonylphenols, Triclosan) routinely occur at low to high levels depending on the source (e.g., residential dwellings, restaurants, vs. convenience stores, etc.) (Conn et al., 2006, Lowe et al., 2009, Conn et al., 2010a) (Table 3). Pharmaceuticals, pesticides, and flame retardants can also occur, but much less pervasively and typically at much lower levels (Conn et al., 2010a). Evaluating Performance of Onsite Unit Operations and Systems Onsite and decentralised systems involve unit operations that can be combined to achieve up to tertiary treatment levels with disinfection. Different types of systems can enable different discharge and reuse options. For onsite and decentralised applications, flow and composition can vary widely, usage can be discontinuous, and the design life can be undefined but often decades long. As a result, the dynamics of performance as affected by design, operation and environment can be quite complex. Research carried out at CSM has investigated the performance of contrasting systems through laboratory experiments, field-testing at the Mines Park Test Site located on the CSM campus, and full-scale systems monitoring. This work has focused in part on optimising the level of treatment to be carried out in a confined unit (e.g., a bioreactor) versus a natural system operation (e.g., a network of soil infiltration trenches) (Figure 2).
Table 3. Concentrations of trace organic compounds associated with consumer product chemicals in wastewaters from 30 small residential, commercial and institutional sources (Conn et al., 2006). Use
Concentration range (μg/L)
0.5–E 9,300 1
Trace organic compound Caffeine
Ethylenediaminetetraacetic acid (EDTA) 4-Methylphenol
Nitrilotriacetic acid (NTA)
5-chloro-2-(2,4-dichlorophenoxy) phenol (Triclosan) 1
E = estimated value (concentration exceeded maximum value on standard curve).
ST-TFU > ST (Figure 3). The TFU achieved an average removal Septic tank w/ efficiency (mg/L) of effluent screen 90% for carbonaceous Soil infiltration Raw BOD5 (cBOD5), 30% for dispersal trenches Wastewater nitrogen, and >95% Septic tank for fecal coliform w/ Textile biofilter bacteria. The removal efficiency of the MBR Disk filter was 99% for cBOD5, Soil drip 61% for nitrogen, dispersal lines Membrane Bioreactor and 100% for fecal Figure 2. Schematic of the onsite wastewater system coliform bacteria. The components involved in treatment unit research at the Colorado School of Mines. dissolved organic carbon in the effluents Onsite Treatment in Septic Tanks, Textile averaged 34, 11, and 6 mg/L for the ST, Biofilters and Membrane Bioreactors In one TFU and MBR, respectively. Organic carbon CSM project, a septic tank, textile biofilter characterisation studies revealed that in unit (TFU), and membrane bioreactor (MBR) addition to reducing the total concentration were established at the Mines Park Test of organic matter in the STE, the TFU and Site and used to treat wastewater from an MBR transformed the organic matter.The 8-unit apartment building. Based on 16–28 STE contained saturated organic compounds months of monitoring, the overall effluent of low to high molecular weight. The TFU quality produced followed this relative effluent had a buildup of humic and fulvic acid material that was more aromatic in ranking (higher to lower quality): ST-MBR >
Studies of full-scale operating systems have also been insightful regarding system design and performance. For example, performance data were available for 30 onsite wastewater treatment systems installed at homes in Colorado (Wren et al., 2004). These data were evaluated and a subset of eight systems employing textile biofilter units was selected for additional investigation. Field monitoring revealed a wide variation in the effluent quality produced for BOD5 (4 to 45 mg/L), TSS (1 to 83 mg/L), and total N (12 to 136 mg/L). A virus tracer using bacteriophages revealed a potential to achieve 99.9% virus removal. While unit operations and systems can have potential to produce high quality effluents, achieving this under field conditions requires proper design and routine operation and maintenance. In another CSM project where trace organic compounds were characterised in wastewaters at 30 sites (see Table 3), additional monitoring was completed to assess removal in septic tanks, biofilters and constructed wetlands (Conn et al., 2006). Removal efficiencies ranged from <1% to >99%, with the efficiency dependent on treatment unit removal mechanisms and the properties of the trace organic compounds. For example, compared to anaerobic treatment in a septic tank, aerobic treatment in a textile biofilter enhanced the removal of trace organic compounds that could be aerobically biodegraded. In a companion project completed at the Mines Park Test Site, this relationship was further revealed, as the removal efficiency in a textile biofilter was generally greater than in a septic tank (Table 4) (Conn et al., 2010b).
Figure 3. Cumulative frequency distributions for the concentrations of COD, total nitrogen and fecal coliform bacteria in the effluents produced by a septic tank (STE), textile biofilter (TFU), or membrane bioreactor (MBR).
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character. The organic matter in the MBR effluent was similar to TFU effluent, but with more developed humic and fulvic acid substances. Directly related to the treatment efficiency achieved, the operational complexity, maintenance requirements, energy use and cost were higher for the MBR compared to the TFU, which was somewhat higher compared to a ST.
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Table 4. Concentrations of trace organic compounds in the effluents from a septic tank versus a textile biofilter used to treat wastewater from an 8-unit apartment building (Conn et al., 2010b). Parameter
Septic tank effluent
Textile biofilter effluent
Ethylenediaminetetraacetic acid (EDTA)
Nitrilotriacetic acid (NTA)
<RL1 of 2
<RL of 1
<RL of 0.2
<RL = result was less than the reporting limit based on the methodology used.
Figure 4. Infiltration rate decline (left) and cumulative mass removal over two years for total N at 60 cm and 120 cm depth below the infiltrative surface (right) (Lowe and Siegrist, 2008).
Figure 5. Illustration of infiltration rate loss due to soil clogging with different effluent qualities applied at 2 or 8 cm/d (model simulations following Siegrist and Boyle, 1987, as reported in Van Cuyk et al., 2005). Onsite Treatment in Soil Treatment Units Onsite and decentralised systems often involve use of soil for wastewater treatment. In this area, CSM research has focused on two onsite system approaches: 1) effluent dispersal into a soil profile using shallow trenches outfitted with infiltration chambers (e.g., Van Cuyk et al., 2005; Lowe and Siegrist, 2008); and 2) effluent dispersal into the plant rhizosphere using drip tubing with pressure-compensating emitters (e.g., Parzen et al., 2007). In one area of emphasis, laboratory experiments and field studies
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revealing the time-dependent and dynamic interaction of unit hydraulics and purification processes for conventional pollutants these studies also provided new insights into the transformation of organic matter and the fate of virus and trace organic compounds. In another project, a replicated factorial design was employed to evaluate three soil infiltrative surface architectures (ISA) (open, gravel-laden or synthetic-stone laden) with domestic STE applied at two daily hydraulic loading rates (HLR) (4 or 8 cm/d) (Siegrist et al., 2005; Lowe and Siegrist, 2008). Pilotscale infiltration trenches were established in Ascalon sandy loam soils at the Mines Park Test Site located on the CSM campus. Based on two years of monitoring, the effluent infiltration rate declined to very low levels due to soil clogging at the infiltrative surface with a time-dependent behaviour that was consistent with model simulations (Figure 4). After this period of decline, an open ISA maintained an infiltration capacity that was 40% to 80% higher than the other ISAs tested. Purification of STE in the soil was very high; the cumulative mass removal for dissolved organic carbon (DOC), total N and total P averaged 94%, 42% and 99%, respectively, while removal of bacteria and viruses exceeded 99.9%. While there was no significant difference in purification based on ISA or HLR, a slight increase in purification was associated with an increase in the soil vadose zone depth (e.g., 120 cm vs. 90 cm below the soil infiltrative surface).
Figure 6. Illustration of relatively consistent soil pore water concentrations despite different effluent qualities applied at 2 or 8 cm/d (20 or 80 L/m2/d) (Lowe and Siegrist, 2008).
Addition of a treatment unit to produce effluent of higher quality than typical STE has the potential to retard soil clogging and enable application of higher HLRs, resulting in smaller soil treatment units. Associated with the treatment unit study described (e.g., see Figure 3), the three effluents were applied to replicate pilot-scale infiltration trenches installed at the Mines Park Test Site (Van Cuyk et al., 2005). The results of bromide tracer tests and infiltration rate measurements made periodically during operation revealed that some degree of soil clogging occurred at the soil infiltrative surface in the sandy loam soil, even with application of the much higher quality TFU or MBR effluents (Figure 5).
have quantified the performance effects of effluent composition, hydraulic loading rate, and infiltrative surface architecture on wastewater treatment in sand filter units and soil infiltration trenches (e.g., Van Cuyk et al., 2001; Van Cuyk et al., 2004, 2005; Beach et al. 2005; Siegrist, 2006; Tomaras et al., 2006; Van Cuyk and Siegrist, 2007; Lowe and Siegrist, 2008; Tomaras et al., 2009; McKinley and Siegrist, 2010). In addition to
When comparing system-wide purification (i.e., ST-soil vs. ST-TFU-soil vs. ST-MBR-soil), pollutant and pathogen removal efficiencies were very high. Moreover, soil pore water concentrations of pollutants (e.g., DOC, N, P) were consistent across different treatment systems and soil depths, even although the applied water qualities were quite different (Figure 6). The ability of a sandy loam soil to remove viruses was quite high (e.g., >99.99%
P Wastewater influent = ~300gal/h (1.14m3/h) ~100 pop. equivalent (based on 70gal/cap/d) P 2 bioreactor tanks each 2,180gal (8.25m³) and 2 membrane tanks each 870gal (3.3m³) Net flux = 19L/(m2.h) (11.2 g/ft2/d)
Figure 7. Sequencing Batch Reactor-Membrane Bioreactor system established on the CSM campus and used for neighbourhood-scale wastewater treatment and water reuse at Mines Park (Cath, 2012). by 60 cm soil depth), and insensitive to whether STE, TFU effluent or MBR effluent had been applied at either 2 or 8 cm/d.
of tailored water reuse for a complex of apartment buildings on the CSM campus in Golden, Colorado (Figures 7 and 8).
To understand the fate of trace organic compounds in a soil treatment unit, a controlled field experiment was completed at the Mines Park Test Site. The effluents from a septic tank or a textile biofilter (Table 4) were applied to the sandy loam soil and the soil pore water was periodically sampled at 60, 120, and 240 cm below the soil infiltrative surface.
For the purposes of this demonstration, tailored water reuse involves generation of water with different concentrations of nitrogen and phosphorus that can be used directly for plant irrigation. Research is investigating the effects of tailored water operations on system performance, including optimised approaches to control biological performance, sustain membrane performance, reduce energy requirements, and ensure robustness of the system.
Purification of trace organic compounds (e.g., caffeine, nonylphenols, Triclosan) in a soil treatment unit principally occurs by sorption and biodegradation processes. Achieving high removal efficiency for a particular organic compound thus depends on the properties of the compound as well as the process conditions present in the soil treatment unit (Conn et al., 2010b). For example, caffeine and Triclosan in septic tank or textile filter unit effluents were completely removed by 60 cm depth through aerobic biotransformation (Conn et al., 2010b). Decentralised Treatment in Membrane Bioreactors Membrane bioreactors can be a viable option for wastewater treatment and water reuse in applications such as neighbourhoods, high-rise apartment buildings or commercial developments. At CSM, a sequencing batch reactor–membrane bioreactor hybrid system (SBR-MBR) has been in operation for four years (Henkel et al., 2011; Cath, 2012; Vuono et al., 2012). The SBR-MBR was established through the Advanced Water Technology Center at CSM (www.aqwatec. com) and is being used in a demonstration
As part of the demonstration, several operational strategies have been examined to determine their effects on effluent quality and energy consumption. Findings to date have revealed that by altering operations, tailored water reuse is possible by controlling the level of N and P removal. Mathematical Models and Decision Support Tools Models and Decision Support Tools can facilitate proper planning and design of onsite and decentralised systems. In one area of emphasis at CSM, analytical
and numerical models of varying scope and complexity have been developed or refined to aid design of an isolated system or clusters of soil treatment units, as well as for assessment of onsite system impacts at the local, development and watershed scale (e.g., Beach and McCray, 2003; McCray et al., 2005; Poeter et al., 2005; Siegrist et al., 2005; Bumgarner and McCray, 2007; Heatwole and McCray, 2007; McCray et al., 2009, 2010; Geza et al., 2009, 2010, 2012). A prime example of a model that can be used to predict purification performance of a soil treatment unit is STUMOD (Soil Treatment Unit Model) (Geza et al., 2009). STUMOD was originally developed to predict the fate and transport of nitrogen in a soil treatment unit. STUMOD calculates nitrogen species concentrations with depth in the soil profile (Figure 9a) and the fraction of nitrogen remaining with depth (Figure 9b). By repeatedly running STUMOD using randomly selected values from ranges of potential input values, the probability that a certain fraction of the total nitrogen in the effluent infiltrated will reach a specified soil depth can be estimated (Figure 9c). Initial operation: SBR-MBR treatment efficiency: 97% COD removal (15.0 mg/L) 40% PO4 removal (3.4 mg/L PO4) 70% N removal (8.8 mg/L NO3-N) (expected N removal = 90%) Optimised operation: SBR-MBR treatment efficiency: 97% COD removal (15.0 mg/L) 90% PO4 removal (< 1 mg/L PO4) 95% N removal (< 2.0 mg/L NO3-N)
Figure 8. Illustration of the effluent quality from the SBR-MBR at Mines Park as affected by operational strategy (Henkel et al., 2011; Vuono, 2012).
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P Average influent concentrations: • COD = 270–560 mg/L • sCOD = 110–210 mg/L • NH4+-N = 24–37 mg/L • Ortho-P = 8–16 mg/L • Solids retention time ~45 days
Technical Features multiple onsite and decentralised systems on water quality within a watershed where numerous sources contribute flow, pollutants and pathogens (McCray et al., 2005; Siegrist et al., 2005; Lemonds and McCray, 2007; McCray et al., 2009; Geza et al., 2010).
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Concentration of N species with depth (mg-N/L)
Mass per time per footprint area (g-N/m2/day)
Probability distribution that a given removal will occur under specific conditions (e.g., there is a 50% probability of 70% nitrogen removal at 60 cm depth)
Figure 9. STUMOD simulation of nitrogen fate when 2 cm/d of STE is applied to a soil treatment unit installed in a sandy loam soil (Geza et al., 2009, 2010, 2012, as reported in McCray et al., 2010). While models such as STUMOD provide insight into the operation of soil treatment units and quantitative estimates of performance as affected by a range of conditions, numerical models can better address many complex processes and lesscommon operating conditions. Modellers at CSM were among the first to use a numerical model, HYDRUS 2-D (Šimunek et al., 1999) to examine the relationships between soil treatment unit design and environmental conditions and the resulting hydraulic and purification performance (e.g., Beach and McCray, 2003; Bumgarner and McCray, 2007; Heatwole and McCray, 2007). Models can be particularly helpful to understand the cumulative effects of
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In a major CSM project, the Watershed Analysis Risk Management Framework model (WARMF) as well as the BASINS/ SWAT and MANAGE models were set up for the Blue River watershed in Summit County, Colorado (Siegrist et al., 2005). This watershed contains over 1,000 onsite wastewater systems and other non-point and point sources of pollution, and over 600 onsite drinking water wells along with community wells and surface water supplies. Compared to urbanised development and centralised wastewater treatment plant discharges, onsite wastewater systems were not a principal source of water pollutants as determined by: 1) source load mass balance calculations; 2) model simulation results; and (3) water quality monitoring and analysis of spatial and temporal trends. Moreover, based on WARMF simulations of different wastewater management scenarios, extending central sewers and conversion of onsite systems to a central treatment plant offered little or no benefit to water quality protection. Achieving System Performance Potential When onsite and decentralised systems are implemented under normal field conditions (i.e., not within a research project), the potential performance based on process principles and research observations may or may not be realised. To achieve a system’s performance potential, the findings of research such as highlighted earlier – as well as observations made during field experiences – have affirmed the need for proper design and assurance that required operation and maintenance activities will occur. Even a simple septic tank unit operation requires proper design and periodic removal and proper disposition of septage. Unit operations and systems that are implemented to achieve high quality effluents in a robust and reliable fashion (e.g., textile biofilters, membrane bioreactors) have operational complexity (e.g., pumps, pressurised piping, aerators, chemical feed, etc.). The more operationally complex a system is, the greater the need for and extent of management and oversight to ensure that the system’s performance potential is actually realised under normal field conditions.
Education Highlights During the past decade or more, research – such as highlighted in this paper – has advanced the science and technology of onsite and decentralised systems. However, research findings do not automatically yield improvements in practices. Clear and compelling research findings can certainly help foster improvements. But improved practices and advances in applications also require translation of research findings so they convey knowledge and know-how to designers, contractors, regulators, policy makers and others. This helps ensure that findings can be adopted into modern regulations and requirements. It is also critical that research findings be incorporated into curriculum for the education of students who can help catalyse improvements and advances. Concerning this latter point, a semester-long course for seniors and graduate students has been developed at CSM and routinely delivered during the past five years. “ESGN460. Onsite Water Reclamation and Reuse” is a 15-week long course focused on the selection, design and implementation of onsite and decentralised wastewater systems. A textbook is being prepared to support delivery of this type of course and Springer will publish it by early 2014.
ACKNOWLEDGEMENTS Numerous individuals and organisations have contributed to the research highlighted in this paper. The efforts of past and current students at CSM are gratefully acknowledged, including: John Albert, Jennifer Bagdol, Debbie Huntzinger-Beach, Kathy Conn, Charlotte Dimick, Sarah Doyle, Kirk Heatwole, Shiloh Kirkland, Paula Lemonds, Andy Logan, Jim McKinley, Rebecca Parzen, Tanja Rauch, Nate Rothe, Kyle Tackett, Mia Tucholke, Dave Vuono, Ryan Walsh and Abigail Wren. Current and former research staff and post-doctoral fellows include: Drs Sheila Van Cuyk, Mengistu Geza and Jochen Henkel. Contributing faculty have included the authors of this paper as well as Drs Jörg Drewes, Eileen Poeter, John Spear and Geoffrey Thyne. Program funding has been acquired through CSM and its Research Foundation, the USEPA National Decentralised Water Resources Capacity Development Project, USGS National Institutes of Water Research, National Science Foundation, Water Environment Research Foundation and Department of Education, along with contracts and philanthropic grants from private industry.
Technical Features REFERENCES
Robert L Siegrist (email: firstname.lastname@example.org) is a University Professor Emeritus of Environmental Science and Engineering at the Colorado School of Mines in Golden, Colorado, US. He is an internationally recognised expert in onsite and decentralised systems for water and sanitation. He has published 300 technical papers and two books, and has delivered invited lectures at more than 100 workshops and conferences in more than 30 countries worldwide.
Beach DN & McCray JE (2003): Numerical Modeling of Unsaturated Flow in Wastewater Soil Absorption Systems. Ground Water Monitoring Remediation, 23(2), pp 64–72.
John E McCray (email: email@example.com) is Professor and Head of the Civil and Environmental Engineering Department at Colorado School of Mines. Professor McCray was the founding Director of the Hydrologic Science and Engineering program at Mines. His research utilises modelling, lab and field experiments to investigate multiphase chemical transport in hydrologic systems. Kathryn Lowe (email: firstname.lastname@example.org) is a Senior Research Associate at the Colorado School of Mines with over 20 years’ experience leading field investigations concerning environmental remediation and natural systems for wastewater reclamation. She is Manager of the Mines Park Test Site. Tzahi Y Cath (email: email@example.com) is an Associate Professor of Environmental Engineering at the Colorado School of Mines. He holds a Bachelor’s Degree in Mechanical Engineering and a PhD in Civil and Environmental Engineering. Dr Cath’s main field of research is membrane processes for wastewater treatment and for desalination. Junko Munakata-Marr (email: firstname.lastname@example.org) is an Associate Professor in Civil and Environmental Engineering at Colorado School of Mines. Her research and teaching interests centre on microorganisms in engineered environmental systems, including biological wastewater treatment, bioremediation and methanogenesis from unconventional sources.
Beach DNH, McCray JE, Lowe KS & Siegrist RL (2005): Temporal Changes in Hydraulic Conductivity of Sand Porous Media Biofilters During Wastewater Infiltration due to Biomat Formation. Journal of Hydrology, 311, pp 230–243. Bumgarner JR & McCray JE (2007): Estimating Biozone Hydraulic Conductivity in Wastewater Soil-Infiltration Systems Using Inverse Numerical Modeling. Water Research, 41(11), pp 2349–2360. Cath TY (2012): ReNUWIt Research Highlights: Tailored Water Reuse. Presentation at the ReNUWit NSF Engineering Research Center Annual Review meeting, Stanford University, Palo Alto, CA, May 2012. Conn KE, Barber LB, Brown GK & Siegrist RL (2006): Occurrence and Fate of Organic Contaminants During Onsite Wastewater Treatment. Environmental Science & Technology, 40, pp 7358–7366. Conn KE, Lowe KS, Drewes JE, Hoppe-Jones C & Tucholke MB (2010a): Occurrence of Pharmaceuticals and Consumer Product Chemicals in Raw Wastewater and Septic Tank Effluent from Single-Family Homes. Environmental Engineering Science, 27, pp 347–56. Conn KE, Siegrist RL, Barber LB & Meyer MT (2010b): Fate of Trace Organic Compounds During Vadose Zone Soil Treatment in an Onsite Wastewater System. Journal of Environmental Toxicology & Chemistry, 29(2), pp 285–293. Crites RC & Tchobanoglous G (1998): Small and Decentralized Wastewater Systems. McGrawHill Publishing Company, Boston, MA. Geza M, McCray JE, Lowe KS, Tucholke M, Wunsch A & Roberts S (2009): A Simple Tool for Predicting Nutrient Removal in Soil Treatment Units. Proc. NOWRA 18th Annual Technical Education Conference, Milwaukee, WI. Geza M, McCray JE & Murray KE (2010): Model Evaluation of Potential Impacts of On-Site Wastewater Systems on Phosphorus in Turkey Creek Watershed, Journal of Environmental Quality, 39, pp 1636–1646. Geza M, McCray JE & Lowe KS (2012): STUMOD – A Tool for Predicting Fate and Transport of Nitrogen in Soil Treatment Units. Environmental Modeling and Assessment, submitted and in review. Heatwole KK & McCray JE (2007): Modeling Potential Vadose-Zone Transport of Nitrogen from Onsite Wastewater Systems at the Development Scale. Journal of Contaminant Hydrology, 91, pp 184–201. Henkel J, Vuono D, Drewes JE, Cath TY, Johnson LW & Reid T (2011): Three Years Experience with a Demonstration Scale SBR-MBR Hybrid System for Onsite Wastewater Treatment and Reuse. Proceedings of the 26th Annual WateReuse Symposium, September 11–14, 2011, Phoenix, AZ. Lemonds PJ & McCray JE (2007): Modeling Hydrology in a Small Rocky Mountain Watershed Serving Large Urban Populations.
Journal of the American Water Resources Association, 43(4), pp 875–887. Lowe KS & Siegrist RL (2008): Controlled Field Experiment for Performance Evaluation of Septic Tank Effluent Treatment During Soil Infiltration. Journal of Environmental Engineering, 134(2), pp 93–101. Lowe KS, Rothe N, Tomaras J, DeJong (Conn) K, Tucholke M, Drewes J, McCray J & Munakata-Marr J (2006): Influent Constituent Characteristics of the Modern Waste Stream from Single Sources: Literature Review. WERF. 04-DEC-1. www.ndwrcdp.org/publications. Lowe KS, Van Cuyk SM, Siegrist RL & Drewes J (2008): Field Evaluation of the Performance of Engineered Onsite Wastewater Treatment Units. ASCE Journal of Hydrologic Engineering, 13(8), pp 735–743. Lowe KS, Tucholke M, Tomaras J, Conn C, Hoppe C, Drewes J, McCray J & Munakata-Marr J (2009): Influent Constituent Characteristics of the Modern Waste Stream from Single Sources. Water Environment Research Foundation, 04-DEC-1. 202 p. www.decentralizedwater.org/research_ project_04-DEC-1.asp. Mayer PW, DeOreo WB, Opitz EM, Kiefer JC, Davis WY, Dziegielewski B & Nelson JO (1999): Residential End Uses of Water. American Water Works Research Foundation, Denver, Colorado. McCray JE, Kirkland SL, Siegrist RL & Thyne GD (2005): Model Parameters for Simulating Fate and Transport of Onsite Wastewater Nutrients. Ground Water, 43(4), pp 628–639. McCray JE, Geza M, Murray K, Poeter E & Morgan D (2009): Modeling Onsite Wastewater Systems at the Watershed Scale: User’s Guide. Water Environment Research Foundation, 04-DEC-6. 242 p. www.decentralizedwater.org/research_ project_04-DEC-6.asp. McCray JE, Geza M, Lowe K, Boving T, Radcliffe D, Tucholke M, Wunsch A, Roberts S, Amador J, Atoyan J, Drewes J, Kalen D & Loomis G (2010): Quantitative Tools to Determine the Expected Performance of Wastewater Soil Treatment Units. Water Environment Research Foundation, DEC1R06. 474 p. www.decentralizedwater.org/ research_project_DEC1R06A.asp. McKinley JW & Siegrist RL (2010): Accumulation of Organic Matter Components in Soil During Conditions Imposed by Wastewater Infiltration. Soil Science Society of America Journal, 74(5), pp 1690–1700. Parzen RE, Tomaras J & Siegrist RL (2007): Controlled Field Performance Evaluation of a Drip Dispersal System Used for Wastewater Reclamation in Colorado. Proc. 11th National Symposium on Individual and Small Community Sewage Systems, Warwick, RI, October 21–24, American Society of Agricultural and Biological Engineers (ASABE), St. Joseph, MI. Poeter E, McCray JE, Thyne G & Siegrist RL (2005): Designing Cluster and High-Density Wastewater Soil-Absorption Systems to Control Groundwater Mounding. Small Flows Journal, 7(4), pp 24–36. Siegrist RL (2001): Perspectives on Advancing the Science & Engineering of Onsite Wastewater Systems. Small Flows Quarterly, 2(4), pp 8–13.
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Technical Features Siegrist RL (2006): Evolving a Rational Design Approach for Sizing Soil Treatment Units: Design for Wastewater Effluent Infiltration. Small Flows Journal, 7(2), pp 16–24.
USEPA (1980): Design Manual for Onsite Wastewater Treatment and Disposal Systems. US Environmental Protection Agency Municipal Environmental Research Laboratory, Cincinnati, Ohio.
Siegrist RL & Boyle WC (1987): Wastewater Induced Soil Clogging Development. Journal of Environmental Engineering, 113(3), pp 550–566.
USEPA (1997): Response to Congress on Decentralized Wastewater Treatment Systems. US Environmental Protection Agency, Office of Water, Washington, DC EPA832/R-47/001b.
Siegrist RL, McCray JE, Weintraub L, Chen C, Bagdol J, Lemonds P, Van Cuyk S, Lowe K, Goldstein R & Rada J (2005): Quantifying Site-Scale Processes and Watershed-Scale Cumulative Effects of Decentralized Wastewater Systems. 587 pp. www.decentralizedwater.org/ research_project_WU-HT-00-27.asp.
USEPA (2002): Onsite Wastewater Treatment Systems Manual. EPA/625/R-00/008. February 2002. www.epa.gov/ord/NRMRL/ Pubs/625R00008/html/625R00008.htm.
Šimunek J, Sejna M & van Genuchten MT (1999): The HYDRUS-2D Software Package for Simulating Two-Dimensional Movement of Water, Heat, and Multiple Solutes in Variably Saturated Media. Version 2.0. Agricultural Research Service, US Department of Agriculture, Riverside, CA. Tomaras JMB, McKinley J, Spear JR & Siegrist RL (2006): Examination of Microbial Characteristics of the Wastewater-Induced Soil Biozone. Proc. 15th Annual Conference, NOWRA, Denver, CO, August 28–30, 2006. Tomaras J, Sahl JW, Siegrist RL & Spear JR (2009): Microbial Diversity of Septic Tank Effluent and a Soil Biomat. Applied and Environmental Microbiology, 75(10), pp 3348–3351.
Van Cuyk S, Siegrist RL, Logan A, Masson S, Fischer E & Figueroa L (2001): Hydraulic and Purification Behaviors and Their Interactions During Wastewater Treatment in Soil Infiltration Systems. Water Research, 35(4), pp 953-964. Van Cuyk S, Siegrist RL, Lowe K, Drewes J, Munakata-Marr J & Figueroa L (2005): Performance of Engineered Treatment Units and Their Effects on Biozone Formation in Soil and System Purification Efficiency. Report to USEPA. 241 pp. www.ndwrcdp.org/publications. Van Cuyk SM & Siegrist RL (2007): Virus Removal Within a Soil Infiltration Zone as Affected by Effluent Composition, Application Rate and Soil Type. Water Research, 41, pp 699–709. Van Cuyk SM, Siegrist RL, Logan A, Masson S, Fischer E & Figueroa L (2001): Hydraulic and Purification Behaviors and Their Interactions
During Wastewater Treatment in Soil Infiltration Systems. Water Research, 35(4), pp 953–964. Van Cuyk S, Siegrist RL, Lowe KS & Harvey RW (2004): Evaluating Microbial Purification During Soil Treatment of Wastewater with Multicomponent Tracer and Surrogate Tests. Journal of Environmental Quality, 33, pp 316-329. Van Cuyk S, Siegrist RL, Lowe KS, Drewes J, Munakata-Marr J & Figueroa L (2005): Performance of Engineered Pretreatment Units and Their Effects on Biozone Formation in Soil and System Purification Efficiency. WUHT-03-36. 241 pp. www.decentralizedwater.org/ research_project_WU-HT-03-36.asp. Van Cuyk S & Siegrist RL (2007): Virus Removal Within a Soil Infiltration Zone as Affected by Effluent Composition Application Rate and Soil Type. Water Research, 41, pp 699–709. Vuono D, Henkel J, Benecke J, Cath TY, Reid T, Johnson L & Drewes JE (2012): Towards Sustainable Distributed Water Reuse within Urban Centers using Flexible Hybrid, Treatment Systems for Tailored Nutrient Management. Water Research, submitted. Wren A, Siegrist R, Lowe KS & Laws R (2004): Field Performance Evaluation of Textile Filter Units Employed in Onsite Wastewater Treatment Systems. Proc. 10th National Symposium on Individual and Small Community Sewage Systems, ASAE. pp. 514–525.
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DO THE AUSTRALIAN GUIDELINES FOR WATER RECYCLING PROTECT SMALL OR REMOTE COMMUNITIES? Many valuable aspects of direct drinking water reuse systems may be particularly useful in small communities SF Barker, M Packer, PJ Scales, S Gray, I Snape, AJ Hamilton
While there are as yet no direct drinking water reuse projects in Australia, there are many valuable aspects of such systems that may be particularly useful in small communities. The Australian Guidelines for Water Recycling – Augmentation of Drinking Water Supplies report a 9.5 log10 reduction value (LRV) of enteric viruses for direct drinking water reuse, based on virus concentrations from a large municipal sewage treatment plant.
Indirect drinking water reuse (IDWR) schemes can be found in many countries; however, direct drinking water reuse (DDWR) is rare. In Australia, there are no DDWR projects either completed or underway, and while IDWR is typically viewed more favourably than DDWR, there have been a number of planned IDWR projects in recent years that have not eventuated due to failure to win community support (Khan, 2011).
Two estimates of sewage concentration were considered: 1) average sewage, assuming that sewage quality was similar to published norovirus values; and 2) outbreak sewage, an estimate of peak pathogen loads during an outbreak of norovirus on station. The estimated LRV for average sewage was 7.0 while for the outbreak scenario it was 12.2. This higher treatment requirement was predominantly attributed to the significantly higher estimate of sewage concentration during a community outbreak. An investigation of the impact of population size showed that the higher LRVs were estimated for the smaller population sizes. It is concluded that safe implementation of direct drinking water reuse in small or remote communities needs to carefully consider the impact of outbreak conditions and will almost certainly require additional treatment barriers to achieve regulatory compliance.
While the more immediate driver of DDWR is extreme water scarcity, various other factors also favour DDWR systems, including whole-of-system life-cycle costs, reliability of water supply and quality, and the exhaustion of economically feasible non-potable reuse options (Leverenz et al., 2011). DDWR systems may prove to be particularly economically viable for small and/or remote communities where other drinking water sources are limited and energy costs are high. Under these circumstances, development of high salinity or otherwise contaminated sources are likely to be uncompetitive, at least on a cost basis, with DDWR (Tchobanoglous et al., 2011). A recent review goes even further, highlighting the key areas that support the consideration of DDWR as an alternative to IDWR including inability to test/validate log removal of ‘environmental buffers’ such as aquifers, vulnerability to climatic conditions and excessive pumping costs (Khan, 2011). Australia is a very large country and there are many small, remote communities where DDWR might be appropriate, particularly with the ever-present threat of drought. Pathogen concentrations in sewage will differ with treatment system size. Wastewater from small communities will have greater variability and higher peak pathogen loads, even if long-term average water quality is similar to larger wastewater treatment systems (Fane et al., 2002). Treatment systems need to be designed to handle peak pathogen loads.
METHOD QMRA was used to determine required log10 reduction values (LRVs) for direct drinking water reuse of wastewater starting from a health target of tolerable annual burden of disease (DB) of ≤10-6 Disability Adjusted Life Years (DALYs) person-1 year-1. This target has been widely adopted for both drinking water and non-potable reuse (NRMMC et al., 2006; WHO, 2006, 2011), but the model used was different in approach to that described in the Guidelines. A stochastic approach (using distributions to describe model input values) was used here to account for variability and uncertainty in the model, while the Guidelines use a deterministic approach, conceding that stochastic analyses may provide a better understanding of uncertainty and variability where sufficient data is available. Norovirus was chosen as the reference pathogen for viruses (using the full norovirus doseresponse model; Teunis et al., 2008) as it is a major cause of community gastroenteritis worldwide (Atmar, 2010; Mattison, 2011); the Guidelines use adenovirus measurements with the rotavirus dose-response model. The model compared two scenarios: average sewage, assuming that sewage quality was similar to published norovirus values from a large municipal wastewater treatment plant; and outbreak sewage, an estimate of peak pathogen loads during a norovirus outbreak. Average sewage concentrations of norovirus were taken from two studies in Japan (Haramoto et al., 2006; Katayama et al., 2008). Defining an outbreak
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Small or remote communities, which are not specifically discussed in the Guidelines, are unique in both the high degree of interaction between community members and the resulting increased risk of disease transmission. For this reason, a quantitative microbial risk assessment (QMRA) was conducted to determine the level of treatment required to meet the tolerable annual disease burden of 10-6 DALYs per person per year for a small community, using Davis Station in Antarctica as a case study.
Therefore, it is important to consider DDWR in the specific context of small communities to determine if there are additional design or operational requirements to ensure safe drinking water during an outbreak. Davis Station, the largest of three permanent Australian research stations in Antarctica, was used as an extreme example of a small, remote community for this study.
Technical Features estimate a minimum required LRV of 9.5 to meet the health target.
DIRECT POTABLE REUSE
Required log10 reduction
Changing population size affected the estimated proportion 11 of the population infected, although it had less of an effect 10 on sewage pathogen concentration and 7 required LRVs to meet the DALY health target. The situation 6 considered here is a worst case scenario where raw wastewater 5 Average Outbreak 10000 1000 100 10 is not diluted with other Population Scenarios wastewater sources Figure 1. Required log10 reductions for direct drinking water (stormwater, rainwater, reuse for various scenarios. The scenarios represent the two etc). With the arrival sewage estimation methods (average and outbreak) and the different population sizes (10,000, 1000, 100, 10). Boxplots of one infected person represent the 25th, 50th and 75th percentiles, while error bars in a population of th th represent the 10 and 90 percentiles; dots represent the 10,000 people it was 5th and 95th percentiles. Data presented accounts for the first 10,000 iterations of the model. estimated that 21.6% of the population as the arrival of one infected person on would be infected, while in a population of station or in the community, concentrations 10, 31.6% would be infected. This affected of norovirus were estimated based on estimated sewage concentrations; values secondary attack rate (mean=0.18), daily per were highest when the modelled population capita water use (mean=132 L), norovirus 11 was only 10 people (mean=8.51x1011 L-1) and shedding concentration (mean=8.2x10 slightly lower for the other three population copies g-faeces-1), daily diarrhoeal faecal sizes (data not shown). The same trend was excretion rate (mean=475 g-faeces observed in estimates of required LRVs person-1) and daily station population with the highest values for the smallest (mean=72). Daily per capita drinking water population size (for a population of 10, consumption was much higher to reflect LRV=12.3; Figure 1) although results were low-humidity conditions at Davis Station similar across all outbreak scenarios. (mean=3 L). Tolerable annual risk was determined accounting for exposure over the summer period only (121 days), norovirus disease burden (3.3x10-3 DALYs case-1) and susceptibility fraction of the population (mean=0.9). The model was also run with discrete populations (10,000, 1000, 100, 10) to explore the impact of population size. A more detailed description is provided in Barker et al. (submitted).
RESULTS The model used two scenarios of sewage concentration. Estimates of norovirus in average sewage (mean=3.12x106 copies L-1) were significantly lower than those determined for outbreak conditions (mean=5.90x1011 copies L-1), which had a direct effect on the estimated required LRVs for Davis Station. For average sewage, the required LRV was 7.0 while for the outbreak scenario it was 12.2 (95th percentile values; Figure 1). Using a different set of assumptions, the Australian Guidelines for Water Recycling â€“ Augmentation of Drinking Water Supplies (NRMMC et al., 2008)
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DISCUSSION Using the 10-6 DALY health target the required LRV was 7.0 in average sewage and 12.2 for estimated outbreak conditions, compared with 9.5 reported in the Guidelines (NRMMC et al., 2008). Using average sewage values, the LRV was much lower than the Guideline value, largely due to the implementation of the norovirus dose-response model. Under outbreak conditions, the LRV was much higher as a direct result of much higher estimates of sewage concentration. The estimate of sewage concentration under outbreak conditions was 1011 which is orders of magnitude higher than published values of municipal sewage concentrations reporting peaks of 103â€“107 (Haramoto et al., 2006; Katayama et al., 2008; Laverick et al., 2004; Lodder and De Roda Husman, 2005; Ottoson et al., 2006a; Ottoson et al., 2006b). Very limited information is available on sewage pathogen concentrations during community gastroenteritis outbreaks; therefore, these values were assumed to be conservative
upper estimates of sewage concentrations. Other model parameters and assumptions were also chosen to be conservative. Small populations have unique properties, distinguishing them from larger population centres and cities. In small populations, there is typically a higher degree of interaction between members of the population relative to that in a large city. As a result, with the arrival of an infected person in the community, the potential spread of a disease could be greater in a small population. This may result in a greater proportion of the population infected or ill during an outbreak, which directly affects the microbial quality of sewage and, ultimately, the level of treatment required for safe wastewater reuse. The estimate of disease spread within a community is based on measures of secondary attack rate taken from studies typically conducted in relatively confined populations such as households and school camps. The conditions at Davis Station are much like those of a school camp and the level of interaction between members of the population is likely quite similar. However, the model almost certainly provides overestimated sewage pathogen concentrations for the larger communities (1000 and 10,000), as the probability of contact with the one infected person decreases with increasing population size (thus reducing the probability of infection and illness per person). In considering the higher required LRVs suggested by this model, it is important to consider the level of risk within the broader context of risk associated with other forms of exposure. The potential exposure pathways include person-to-person contact, contact with contaminated surfaces and inhalation/ ingestion of aerosols. The assumption of the model, that one infected person arrives on station, would result in up to 18 people infected (95th percentile) through personto-person contact (all contact methods considered in determining secondary attack rate). In contrast, for the hypothetical outbreak scenarios which assume all infected individuals shed pathogens at the peak rate and that treatment of sewage conforms to the required LRVs needed to meet the 10-6 DALY health target, consumption of the treated water (at an LRV of 12.2) would result in 0.12 additional cases per summer season using 95th percentile station population values. Careful consideration will be required to design a treatment system to meet safe drinking water requirements in the event of an outbreak of gastroenteritis in a small
Technical Features community, likely requiring a combination of treatment systems. Treatment systems are typically designed to provide a multibarrier approach to ensure water quality, but may only be validated for a virus LRV of approximately 9.5, in keeping with the Guidelines. Based on the higher required LRVs suggested by this model, it is proposed that additional treatment units will be needed to increase the LRV of wastewater reuse systems for small communities.
CONCLUSION DDWR may provide a valuable option to enhance water security in small and large communities. The results of this analysis have highlighted the potentially higher risks associated with DDWR in small communities, as a function of the greater degree of interaction between members of the community and, therefore, greater risks of infection during an outbreak.
Generalisation to other small communities is relevant and the model results indicate that design and operation of a treatment plant to meet safe drinking water requirements in the event of a small community outbreak of gastroenteritis is far more challenging than in a large city. Additional treatment barriers will be necessary to achieve regulatory compliance for safe drinking water for such communities.
ACKNOWLEDGEMENTS The Authors would like to thank members of the AAD Polar Medicine Unit for providing context and a clearer understanding of station conditions. Helpful comments and suggestions were also received from Dr Martha Sinclair (Monash University). Funding for this work through the Cooperative Research Network (CRN) program of the Australian Government and the Australian Antarctic Division of the Department of Sustainability, Environment, Water, Populations and Communities of the Australian Government is also gratefully acknowledged.
Fiona Barker (email: fionabr@ unimelb.edu.au) is a Research Scientist at the Department of Resource Management and Geography, The University of Melbourne, Victoria. Michael Packer (email: Michael.Packer@ aad.gov.au) is a Project Engineer, Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and Communities, Tasmania. Peter J Scales (email: email@example.com. au) is Leader, National Water Productivity and Innovation Hub, The University of Melbourne, Victoria. Stephen Gray (email: firstname.lastname@example.org. au) is Director, Institute for Sustainability and Innovation, Victoria University, Melbourne, Victoria. Ian Snape (email: Ian.Snape@aad. gov.au) is Principal Research Scientist, Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and Communities, Tasmania. Andrew J Hamilton (email: andrewjh@ unimelb.edu.au) is Senior Research Fellow and Science Director, Dookie 21, The University of Melbourne, Victoria.
REFERENCES Barker S, Packer M, Scales P, Gray S, Snape I & Hamilton A (submitted): Pathogen Reduction Requirements for Potable Reuse in Small Communities: A Comparison with Recycled Water from Municipal Sewage. Water Research. Fane SA, Ashbolt NJ & White SB (2002): Decentralised Urban Water Reuse: The Implications of System Scale for Cost and Pathogen Risk, Water Science and Technology, 46 (6-7), pp 281–288. Haramoto E, Katayama H, Oguma K, Yamashita H, Tajima A, Nakajima H & Ohgaki S (2006):
Laverick MA, Wyn-Jones AP & Carter MJ (2004): Quantitative RT-PCR for the Enumeration of Noroviruses (Norwalk-like Viruses) in Water and Sewage. Letters in Applied Microbiology, 39(2), pp 127–136. Leverenz HL, Tchobanoglous G & Asano T (2011): Direct Potable Reuse: A Future Imperative. Journal of Water Reuse and Desalination, 1(1), pp 2–10. Lodder WJ & De Roda Husman AM (2005): Presence of Noroviruses and Other Enteric Viruses in Sewage and Surface Waters in The Netherlands. Applied and Environmental Microbiology, 71(3), pp 1453–1461. NRMMC, EPHC & AHMC (2006): Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase 1). Natural Resource Management Ministerial Council, Environment Protection and Heritage Council, Australian Health Ministers’ Conference, Canberra. NRMMC, EPHC & NHMRC (2008): Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase 2). Augmentation of Drinking Water Supplies. Natural Resource Management Ministerial Council, Environment Protection and Heritage Council, National Health and Medical Research Council, Canberra. Ottoson J, Hansen A, Bjorlenius B, Norder H & Stenstrom TA (2006a): Removal of Viruses, Parasitic Protozoa and Microbial Indicators in Conventional and Membrane Processes in a Wastewater Pilot Plant. Water Research, 40(7), pp 1449–1457. Ottoson J, Hansen A, Westrell T, Johansen K, Norder H & Stenstrom TA (2006b): Removal of Noro- and Enteroviruses, Giardia Cysts, Cryptosporidium Oocysts, and Fecal Indicators at Four Secondary Wastewater Treatment Plants in Sweden. Water Environment Research, 78(8), pp 828–834. Tchobanoglous G, Leverenz H, Nellor MH & Crook
Seasonal Profiles of Human Noroviruses and
J (2011): Direct Potable Reuse: A Path Forward.
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Plant in Tokyo, Japan. Water Science and Technology, 54, pp 301–308. Katayama H, Haramoto E, Oguma K, Yamashita H, Tajima A, Nakajima H & Ohgaki S (2008):
Teunis PFM, Moe CL, Liu P, Miller SE, Lindesmith L, Baric RS, Le Pendu J & Calderon RL (2008): Norwalk Virus: How Infectious Is It? Journal of Medical Virology, 80(8), pp 1468–1476.
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The model estimated an LRV of 12.2 for outbreak conditions, indicating the need for additional treatment barriers for small communities in order to provide safe drinking water. This higher treatment requirement is predominantly attributed to the significantly increased pathogen levels in outbreak sewage relative to municipal sewage from a large city. The recommended LRV clearly represents a worst-case scenario, assuming high pathogen concentrations and close community contact.
FAECAL INDICATORS AND PATHOGENS IN POTABLE RAINWATER TANKS IN SOUTH-EAST QUEENSLAND An assessment of the microbiological quality of tank water and connected household tap water in 24 households on the Gold Coast
W Ahmed, S Toze, JPS Sidhu
In this study, the microbiological quality of tank water (TW) and connected household tap water (CHTW) fed from TW was assessed by monitoring faecal indicator bacteria (FIB) and zoonotic pathogens from 24 households in South-East Queensland (SEQ). The numbers of zoonotic pathogens were also estimated in faecal samples from possums and various species of birds, as both possums and birds are considered to be potential sources of faecal contamination in TW. Among the 24 households, 63% TW and 58% CHTW samples were positive for E. coli and exceeded the Australian Drinking Water Guidelines value of > 1 CFU E. coli per 100mL of water. In all, 21%, 4% and 13% TW samples were positive for Campylobacter spp., Salmonella spp., and Giardia lamblia, respectively. Similarly, 21% and 13% CHTW samples were positive for Campylobacter spp. and G. lamblia, respectively. A number of possum and bird faecal samples were also positive for Campylobacter spp., Cryptosporidium parvum and G. lamblia, with high numbers suggesting possum and bird faeces may be contaminating TW.
In Australia, roof-captured rainwater (RCR) has been considered as a potential source for both drinking and various non-potable uses, such as irrigation, toilet flushing, car washing, showering and clothes laundering. Around 10% of Australian people use RCR as a major source of their drinking water, and an approximate additional 5% use RCR as potable replacement for showering, toilet flushing and clothes laundering (ABS, 2007). There is also a general community perception that RCR is safe to drink without having to undergo prior treatment.
FIB inactivation rates were measured and the data suggest their longer persistence in the TW compared to the roof and gutter environment. When introduced to the TW, a slow inactivation process appears to take place (T90 = 10-15 days). In addition, a portion of E. coli in TW appears to be sourced from possum and bird faeces. Maintenance of good roof and gutter hygiene and elimination of overhanging tree branches and other perching on mounted structures on the roof where possible to prevent the gathering of possums and birds should be considered to minimise faecal contamination on the roof and in the gutter. It is recommended that rainwater should be treated with effective treatment procedures such as filtration, disinfection or simply boiling the water prior to drinking.
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In support of this perception, Dillaha and Zolan (1985) reported that the quality of RCR is generally acceptable for drinking and household use. This was further supported by an epidemiological survey of gastroenteritis among four- to six-yearold children in rural South Australia who drank rainwater or treated mains water; the research findings suggested RCR poses no increased risk of gastroenteritis (Heyworth et al., 2006; Rodrigo et al., 2011). Nonetheless, there is still a lack of universal regulatory acceptance to allow or recommend that RCR should be used for drinking where town water is available. For example, in Queensland, the use of water from rainwater tanks for drinking is not supported if there is town water available. However, if a person chooses to use rainwater for drinking or any other potable purpose, then recommendations are made to treat the water prior to drinking. It is noted that under such circumstances, the person is responsible for ensuring the quality of the water is fit for its intended use. There is concern that the quality of RCR may not be as good as perceived. A wide range of pathogens is known to be present in the faeces of wild birds, insects, mammals and reptiles that have access to the roof. Consequently, following rain events, animal faecal droppings and other organic debris
deposited on the roof and gutter can be transported into the tank with roof runoff. A number of studies on the microbial quality of RCR have reported the presence of faecal indicator bacteria (FIB) and zoonotic bacterial or protozoa pathogens in individual or communal tank water (TW) (Ahmed et al., 2008; Birks et al., 2004; Crabtree et al., 1996; Simmons et al., 2001). Legitimate concerns, therefore, have arisen from health regulators regarding the microbiological quality of RCR. Little is known, however, regarding the prevalence of zoonotic pathogens in wild animals such as birds and mammals that are most likely to contaminate RCR. Little is also known regarding the sources of faecal contamination in rainwater tanks. Knowing the source of FIB or pathogens is important in order to devise appropriate management strategies. The aims of this study were to (i) investigate the prevalence and numbers of FIB (E. coli and Enterococcus spp.), zoonotic bacterial (Campylobacter spp. and Salmonella spp.) and zoonotic protozoa (Cryptosporidium parvum and Giardia lamblia) pathogens in TW and connected household tap water (CHTW); (ii) investigate the prevalence of the afore-mentioned pathogens in faecal samples from possums and various species of wild birds; and (iii) investigate the inactivation rates of FIB in particular, on the roof and in the gutter in particular, and as well as in the TW. In addition, an attempt was also made to identify the likely sources of E. coli by comparing strains isolated from TW and animal faeces that harbour toxin genes.
MATERIALS AND METHODS MICROBIOLOGICAL ANALYSIS OF TW, CHTW AND ANIMAL FAECAL SAMPLES Twenty-four households from the Currumbin Ecovillage, Gold Coast, participated in this study. All households use RCR for drinking and for non-potable uses such as car washing, cloth laundering, showering,
Technical Features gardening etc. Two water samples were collected from each household (one directly from the tank and one from the connected household tap), giving a total of 48 samples from 24 households. Samples were collected in 20L sterile containers within one to four days after a rain event (> 100 mm). Before sampling, the external taps (attached to the tank) and internal household taps were wiped with 70% ethanol and allowed to run for 30 to 60s to flush water. Brushtail possum faecal samples were collected by licensed approved handlers (n=40), while wild bird (n=38) faecal samples were collected from birds located in the Brisbane botanical garden, Currumbin Bird Sanctuary and a veterinary hospital. The membrane filtration method was used to process water samples for FIB enumeration, as described elsewhere (Ahmed et al., 2008). 19L of TW and CHTW samples were then concentrated by hollow-fibre ultrafiltration system (HFUS) as previously described (Hill et al., 2005). For quantitative PCR (qPCR) analysis of pathogens, DNA was extracted from the concentrated samples using a DNeasy Blood and Tissue Kit (Qiagen, Valencia, CA). DNA was extracted from fresh faeces (80–220mg) from each individual animal using a QIAmp Stool DNA kit (Qiagen). The qPCR reaction mixtures and cycling parameters used for the detection of the zoonotic pathogens have been described elsewhere (Ahmed et al., 2012a). FIB and pathogen numbers were Log10 transformed. A Wilcoxon signed-rank test was applied to test the significance of difference in faecal indicators and pathogen numbers between TW and CHTW samples. A difference was considered significant if the P value was < 0.05. FIB INACTIVATION ANALYSIS
sediment (similar to dirty urban household gutters). The petri dishes were kept under the moist sediment containing vegetation and organic debris. The inactivation experiment in TW was undertaken using diffusion chambers as previously described elsewhere (Sidhu and Toze, 2012). Wild E. coli and Enterococcus spp. isolates were added to the TW sample matrix to achieve final numbers of approximately 3.6 × 106 E. coli and 1.4 × 107 Enterococcus spp. per mL of water. The seeded TW sample was distributed equally into 24 diffusion chambers. All of the assembled diffusion chambers were suspended in the TW at a depth of 1 metre below the water level. Sequential samples from petri dishes (0, 1, 2, 3, 4, 6, 8, 24, 48 and 72h of exposure time) and diffusion chambers (1, 2, 4, 6, 10, 17, 24 and 34 days of exposure time) were serially diluted and the surviving numbers of E. coli and Enterococcus spp. were enumerated using spread plate method as described elsewhere (Sidhu et al., 2008). For each tested FIB, all determined numbers in each replicate sample for each sampling occasion were converted to log10 values and plotted against over time. The results were also reported as a T90 time, which was determined using inactivation rates formula described elsewhere (Sidhu et al. 2008). Statistical significances of the results were determined by applying a student’s t-test to the T90 values (time required for the reduction of 1 log or 90%). The critical P-value for the test was set at 0.05. IDENTIFICATION OF SOURCES OF E. COLI HARBOURING TOXIN GENES IN RAINWATER TANKS A total of 200, 214 and 214 E. coli isolates were isolated from the 22 TW samples, 40 possum faecal and 38 wild bird faecal samples, respectively from Brisbane and the Gold Coast region in SEQ. All E. coli isolates were tested for the presence of 10 E. coli toxin genes
(stx1, stx2, hlyA, ehxA, LT1, ST1, cdtB, east1, cnf1 and cvaC) associated with intestinal and extra-intestinal diseases. PCR detection of toxin genes was undertaken using previously published primers and cycling parameters as described elsewhere by Ahmed et al. (2012b). All E. coli isolates harbouring one or more toxin genes were biochemically fingerprinted using the PhPlate system (PhPlate AB, Stockholm, Sweden) (Kühn et al., 1995). The biochemical fingerprints were compared pair-wise and the resulting similarity matrix was clustered according to the unweighted pair group method (UPGMA) method. BPTs showing similarity to each other above the IDlevel were regarded as identical.
RESULTS NUMBERS OF FIB AND PATHOGENS IN TW AND CHTW SAMPLES The percentage of TW and CHTW samples positive for FIB and pathogens is shown in Figure 1. The numbers of E. coli ranged from 1 to 230 CFU per 100mL (for TW) and 1 to 300 CFU per 100mL (for CHTW). For Enterococcus spp., the corresponding numbers were 2 to 110 CFU per 100mL (for TW) and 1 to 110 CFU per 100mL (for CHTW). For the estimation of pathogen numbers, genomic copies (determined by qPCR) of each pathogen were converted to numbers of bacterial cells or protozoa cysts. The number of Campylobacter spp. in TW and CHTW samples ranged from 5 to 100 cells (in TW) and 10 to 190 cells (in CHTW) per L of water, respectively. Similarly the estimated number of Salmonella spp. was 7,300 cells (in TW) per L of water. The numbers of G. lamblia cysts ranged from 120 to 580 (in TW) and 110 to 140 (in CHTW) per L of water. The number of E. coli (P = 0.78), Enterococcus spp. (P = 0.64), Campylobacter spp. (P = 0.44) and G. lamblia (P = 0.50) in TW did not significantly differ from those numbers in CHTW samples.
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For FIB inactivation, an RCR system comprised of a 3,000L polyethylene tank, a 2m2 roof constructed with corrugated iron sheets and gutter made with corrugated iron with plastic downpipes leading water into the tank. Known numbers of wild E. coli and Enterococcus spp. were seeded into possum faecal slurry giving a final number of approximately 108 E. coli and Enterococcus spp. per mL of slurry. For the roof and gutter inactivation experiments, 5mL of faecal slurry was poured into a series of petri dishes and placed on the corrugated iron roof and in the gutter of the experimental structure. For the roof experiment, one set of petri dishes was kept directly under sunlight and another set was kept in the shade. The shade on the roof was artificially created by placing a tarpaulin over the petri dishes. For the gutter experiment, a set of petri dishes was placed in the clean segment of the gutter and another set was placed in a dirty gutter. The gutter was made dirty by filling with moist
Figure 1. Percentage of tank water (TW) and connected household tap water (CHTW) samples positive for faecal indicator bacteria (FIB) and zoonotic pathogens.
Table 1. Numbers of zoonotic pathogens in possum and bird faecal samples. Samples
Range of bacterial and protozoa pathogens per gm of faeces Campylobacter spp.
6.6 × 10 to 6.6 × 10
630 to 1,800
1.3 to 120
2.0 × 105 to 2.0 × 107
21 to 1,600
ND: Not detected
Table 2. Inactivation rates (T90 in h) of Escherichia coli and Enterococcus spp. on the roof, in the gutter and in the tank water (TW). Faecal indicators
were observed in E. coli inactivation compared to Enterococcus spp. in the TW (paired t-test, P = 0.167). OCCURRENCE OF TOXIN GENES IN TW, POSSUM AND BIRD FAECAL SAMPLES
Among the 10 E. coli toxin genes tested, four genes Enterococcus spp. Roof Sunlight 1.5 (ST1, east1, cdtB and cvaC) Shaded 211.5 were detected in 43 of 200 Gutter Clean 2 E. coli strains isolated from Dirty 5.6 rainwater tanks (Table 3). The remaining toxin genes stx1, TW 233 stx2, hlyA, exhA, LT1 and cnf1 NUMBERS OF ZOONOTIC could not be detected in any PATHOGENS IN ANIMAL of the isolates tested. Three toxin genes FAECAL SAMPLES (east1, cdtB, cvaC) were detected in 55 of 214 E. coli strains from bird faecal samples. Among the 40 possum faecal samples tested, Only east1 toxin gene was detected in E. the Campylobacter spp. 16S rRNA, C. parvum coli strains from 17 (42.5%) of the 40 possum COWP and G. lamblia ß-giardin genes were faecal samples. The remaining toxin genes detected in 60%, 13% and 30%, respectively. could not be detected in any of the isolates Among the 38 bird faecal samples tested, the tested from possum faecal samples. Campylobacter spp. 16S rRNA, Salmonella invA, C. parvum COWP and G. lamblia ß-giardin genes were detected in 24%, 11%, 5% and 13% samples respectively. The range in numbers of pathogens detected in possum and bird faecal samples are shown in Table 1.
SOURCE TRACKING OF E. COLI IN TANK WATER (TW) Using the results of the analysis of the virulence genes and phenotypic biochemical fingerprinting, a cluster analysis was used to compare the fingerprints of the 43 TW strains with those from bird (n = 55) and possum (n = 74) faecal samples. 33% strains from 7 TW samples were identical to strains from birds, and 21% strains from 6 TW samples were identical to strains from possums. In contrast, 51% strains from TW could not be correlated with the possum or bird samples (Figure 2).
DISCUSSION FIB AND PATHOGENS IN TW AND CHTW SAMPLES In this study, 62% of the TW and 58% of the CHTW samples fed from rainwater tanks exceeded Australian Drinking Water Guidelines (ADWG 2011) of < 1CFU E. coli per 100mL water. The pooled numbers of E. coli and Enterococcus spp. in the CHTW samples did not differ significantly from the numbers found in TW samples. The presence of FIB in the CHTW samples was not unexpected, because 58% of households did not use any treatment methods. Although 10 (42%) households had under-sink filtration (USF) installed, these systems did not appear to be effective in removing FIB.
FIB INACTIVATION Under direct sunlight, E. coli rapidly inactivated (T90 = 1.7 h) compared to in shade, where a slow inactivation rate (T90 = 120 h) was observed (Table 2). Similar results were also obtained for Enterococcus spp. with sunlight inactivation compared to shaded conditions. Significant differences were observed between sunlight and shaded conditions for both E. coli (paired t-test, P = 0.024) and Enterococcus spp. (paired t-test, P = 0.013). The inactivation rates of FIB in possum faecal slurry were evaluated in the gutter under sunlight conditions only. E. coli inactivation rates were similar for both clean (T90 = 51 h) and dirty (T90 = 46.2) gutters. Enterococcus spp., however, showed relatively rapid inactivation in clean (T90 = 2 h) and dirty (T90 = 5.6 h) gutters. The inactivation rates of FIB were also determined under insitu conditions in the TW. The estimated T90 values for E. coli and Enterococcus spp. were 345h and 233h, respectively. No differences
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Figure 2. Percentage of E. coli strains from TW that were classified into sources. Table 3. Occurrence of Escherichia coli-harbouring toxin genes in TW, possum and bird faecal samples. Samples
No. of E. coli tested
Distribution of E. coli toxin genes
No. of E. coli isolates harbouring toxin genes (%)
ND: Not detected.
Technical Features Campylobacter spp. was detected in three (21%) of the 24 TW samples. These households had either overhanging trees or evidence of wild life faecal droppings on the roofs. Two households had USF installed, however, Campylobacter spp. was still detected in the CHTW samples, suggesting the poor efficacy of their USF systems. G. lamblia was detected in three (13%) of the 24 TW samples tested in this study. Two of these households had wild life faecal droppings on the roof. All three CHTW samples were also positive for G. lamblia. It has to be noted that these households did not apply any treatment methods for rainwater disinfection/purification prior to drinking. Salmonella spp. was detected in one TW sample, whereas none of the CHTW samples were positive for Salmonella spp. To identify the likely sources of these pathogens in TW samples, wild birds and possum faecal samples were screened, as these animals are the likely sources of faecal contamination in TW. A number of possum and bird faecal samples were positive for Campylobacter spp. and G. lamblia, suggesting these animals may have probably contributed to these pathogens in TW samples. Previous research studies also reported the presence of G. lamblia in possum and bird faeces in North Island, New Zealand (Chilvers et al., 1998; Marino et al., 1992). Giardia cysts were also detected in faecal samples from cats, rats and mice in the New Zealand study and, therefore, these animals could possibly also contribute Giardia to the TW samples. In this study, five possum and two bird faecal samples were also positive for C. parvum. Other animals such as lizards, frogs and flying foxes that have access to the roof cannot be ruled out as possible sources of bacterial and protozoa pathogens in TW.
INACTIVATION STUDY E. coli and Enterococcus spp. became inactivated more rapidly on the roof under sunlight conditions compared to shaded conditions. The average daily minimum and maximum temperature over the sampling period for sunlight and shaded conditions were similar and, therefore, appeared not to have played any significant role in FIB inactivation. Loss of moisture through rapid evaporation may have been a significant factor leading to the faster inactivation observed for sunlight conditions compared to shaded conditions. Since moist conditions are essential for the viability of metabolically active bacteria (Sinton et al. 2002; Ward et al. 1981) it is most likely that it was the drying of the faecal material that was responsible for the rapid loss of the FIB bacteria. The similar inactivation rates of FIB in the gutter suggested that organic matter and vegetation in the dirty gutter did not influence the inactivation rates compared to the clean gutter, although Enterococcus spp. survived for a relatively shorter period of time than E. coli in both the dirty and clean gutters. We acknowledge that clean and dirty gutter experiments were undertaken under sunlight conditions only. It is highly likely that faecal indicators would inactivate more slowly under shaded conditions, similar to the roof shade experiment. Nonetheless, the results suggest that gutters should remain free of debris and vegetation, because over time dirty gutters may provide sufficient shelter to FIB and pathogens from inactivation factors such as increased temperature or desiccation as suggested previously by Cunliffe (1998). The most important component of the RCR system is the storage tank. It is, therefore, imperative to understand inactivation rates of FIB in TW that is used for potable or non-potable purposes. When comparing the two FIB groups, the results indicated that Enterococcus spp. became inactivated more rapidly than E. coli. Faecal coliforms have been shown to have a greater persistence in freshwater than Enterococcus spp. (Sinton et al., 2002),
which would explain this distinction in rainwater tanks. Much slower inactivation rates were observed for both indicators in the TW compared to the roof and gutter experiments. This is not unexpected, considering the fact that FIB in TW were not exposed to the harsh meteorological conditions similar to roof and gutter experiments. It is possible that certain strains of FIB could have survived better than others in the TW, on the roof and in the gutter, since faecal strains were used for spiking in this study. While there is good information on the survival of FIB on the roofs, gutters and in tanks, research remains to be undertaken on the survival of the zoonotic pathogens to determine what similarities or differences exist in the survival of the FIB and the actual pathogenic microorganisms. SOURCE TRACKING A number of E. coli strains from TW were positive for toxin genes. To identify the likely sources of these potential clinically significant E. coli in TW, a source-tracking approach was undertaken. A biochemical fingerprinting method was also used for typing of these E. coli strains. In this study, it was postulated that fingerprints of E. coli strains from bird and possum faecal samples and TW samples harbouring toxin genes can be compared with each other to identify the likely sources of these strains in TW samples. One important feature of such an approach is that the analysis is focused on strains carrying toxin genes rather than commensal E. coli of little health significance. Of the 43 strains isolated from rainwater tank samples, 33% were identical to those found in bird faeces and 21% identical to isolates from possum faecal samples. The remaining 51% strains could not be correlated with any of the tested possum or bird isolates. This may be due to the fact that the number of bird and possum faecal samples tested in this study did not capture the diversity of E. coli in TW samples. It is also possible that a portion of these unidentified strains might have originated from other sources such as rats, lizards, frogs or fruit bats, which were not tested in this study. A recent study also reported the presence of E. coli and pathogenic microorganisms in airborne particulate matter and in water samples from rainwater tanks in the tropical atmosphere in Singapore (Kaushik & Balasubramanian, 2011), which may account for another potential source of unidentified strains in TW in sub-tropical SEQ. The rainwater tanks that contained E. coliharbouring toxin genes were surveyed. Of
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The results of this study indicate that certain householders were potentially exposed to pathogenic bacteria and protozoa; however, no increase in reported cases of illnesses has been reported in the notifiable diseases database in SEQ. This could be due to the natural incidence of gastroenteritis in the community masking any TW source of disease (Hellard et al., 2001). Before the disease can be reported in the Notifiable Diseases Surveillance System, it must first be identified, and not every individual will seek medical attention if the illness is mild and lasts only for a few days. Another factor is the possibility of individuals acquiring immunity to certain pathogens due to frequent exposure. We also acknowledge that qPCR results obtained in the study do not provide
information regarding the viability or pathogenicity of the target microorganisms. Therefore, in this study it cannot be ruled out that the pathogen detections were the DNA from non-viable pathogens. The evidence obtained suggests, however, that there is the potential for viable pathogens to be present in RCR along with the associated health risks and, therefore, treatment of RCR should be undertaken prior to use for potable purposes.
Technical Features the 13 tanks, 12 tanks had either visible faecal droppings on the roof, or overhanging trees, or both (data not shown). It has been suggested that rainwater tanks should be appropriately maintained, including ensuring the cleanliness of the roofs and gutters periodically, while the receiving tanks should be cleaned at least two times per year to improve the quality of water (Cunliffe, 1998). These results showing the presence of E. coli-harbouring toxin genes in bird and possum faecal samples reinforces the need for good maintenance of roofs and gutters and elimination of overhanging tree branches to protect potential public health risks.
CONCLUSIONS The presence of potential pathogens, along with the presence of one or more indicators, indicates a poor level of microbial quality of TW and CHTW. These pathogens could represent a potential health risk to end users, especially those who use the water for drinking and kitchen use. Approximately 10% of Australian people use rainwater for potable purposes and, therefore, it is recommended that captured rainwater should be treated with effective treatment procedures such as filtration, disinfection or simply boiling the water prior to drinking. From our data, it appears that FIB can survive on the roof under favourable conditions and can be transported to the tank during rainfall events. If deposited on a shaded location on a roof, and within a short time period prior to a rain event, viable micro-organisms could be flushed into the rainwater tank system. When introduced to the TW, a slow inactivation process may take place (T90 = 10-15 days). Microbial source tracking data also suggests possum and birds are contributing to FIB and pathogens in TW. Maintenance of good roof and gutter hygiene and elimination of overhanging tree branches and other mounted structures on the roof where possible to prevent the access of possums and birds should be considered to minimise faecal contamination on the roof and in the gutter.
ACKNOWLEDGEMENTS This research was undertaken and funded as part of the Queensland Urban Water Security Research Alliance, a scientific collaboration between the Queensland Government, CSIRO, The University of Queensland and Griffith University. We thank residents of South-East Queensland who provided access to their houses for collecting samples. We also thank “Peter the Possum Man” for providing possum faecal samples.
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Cunliffe D (1998): Guidance on the Use of Rainwater Tanks. National Environmental Health Forum Monographs, Water Series No. 3. National Environmental Health Forum, Adelaide, Australia. Dillaha TA & Zolan WJ (1985): Rainwater Catchment Water Quality in Micronesia, Water Research, 19, pp 741–746.
Dr Warish Ahmed (email: Warish.Ahmed@ csiro.au) is a Water Microbiologist with CSIRO Land and Water Division. His area of expertise includes faecal pollution tracking and detection and quantification of pathogens in alternative water sources. Dr Simon Toze (email: Simon.Toze@csiro. au) is a Research Team Leader with CSIRO Land and Water Division and the Water for a Healthy Country Flagship, as well as an honorary Associate Professor with the UQ School of Population Health. Dr Jatinder Sidhu (email: Jatinder.Sidhu@ csiro.au) is a Research Scientist in the Urban and Industrial Water research theme of CSIRO Land and Water. He is an Environmental microbiologist with 10 years of experience in public health related water Microbiology.
REFERENCES ABS (2007): Environmental Issues: People’s Views and Practices, No. 4602.0. Australian Bureau of Statistics, Canberra. ADWG (2011): Guidelines for Drinking Water Quality in Australia, National Health and Medical Research Council/Australian Water Resources Council. Ahmed W, Huygens F, Goonetilleke A & Gardner T (2008): Real-Time PCR Detection of Pathogenic Microorganisms in Roof-Harvested Rainwater in Southeast Queensland, Australia, Applied and Environmental Microbiology, 74, pp 5490–5496. Ahmed W, Hodgers L, Sidhu JPS & Toze S (2012a): Fecal Indicators and Zoonotic Pathogens in Household Drinking Water Taps Fed from Rainwater Tanks in Southeast Queensland, Australia, Applied and Environmental Microbiology, 78, pp 219–226. Ahmed W, Sidhu JPS & Toze S (2012b): An Attempt to Identify the Likely Sources of Escherichia coli Harboring Toxin Genes in Rainwater Tanks, Environmental Science & Technology, 46, pp 5193–5197. Birks R, Colbourne J, Hills S & Hobson R (2004): Microbiological Water Quality in a Large Inbuilding Water Recycling Facility, Water Science and Technology, 50, pp 165–172. Chilvers BL, Cowan PE, Waddington DC, Kelley PJ & Brown TJ (1998): The Prevalence of Infection of Giardia spp. and Cryptosporidium spp. in Wild Animals on Farmland, Southeastern North Island, New Zealand, International Journal of Health Research, 8, pp 59–64. Crabtree KD, Ruskin RH, Shaw SB & Rose JB (1996): The Detection of Cryptosporidium Oocysts and Giardia cysts in Cistern Water in the US. Virgin Islands, Water Research, 30, pp 208–216.
Hellard ME, Sinclair MI, Forbes AB & Fairley CK (2001): A Randomized Blinded, Controlled Trial Investigating the Gastrointestinal Health Effects of Drinking Water Quality. Environmental Health Perspectives, 109, pp 773–777. Heyworth JS, Glonek G, Maynard EJ, Baghurst PA & Finlay-Jones J (2006): Consumption of Untreated Tank Rainwater and Gastroenteritis Among Young Children in South Australia, International Journal of Epidemiology, 35, pp 1051–1058. Hill VR, Polaczyk AL, Hahn D, Narayanan J, Cromeans TL, Roberts JM & Amburgey JE (2005): Development of a Rapid Method for Simultaneous Recovery of Diverse Microbes in Drinking Water by Ultrafiltration with Sodium Polyphosphate and Surfactants, Applied and Environmental Microbiology, 71, pp 6878–6884. Kaushik R & Balasubramanian R (2011): Assessment of Bacterial Pathogens in Fresh Rainwater and Airborne Particulate Matter Using Real-Time PCR. Atmospheric Environment, 46, pp 131–139. Kühn I, Katouli M, Wallgren P, Söderlind O & Möllby R (1995): Biochemical Fingerprinting as a Tool to Study the Diversity and Stability of Intestinal Microfloras, Microecology and Therapy, 23, pp 140–148. Marino MR, Brown TJ, Waddington DC, Brockie RE & Kelly PJ (1992): Giardia intestinalis in North Island Possums, House Mice and Ship Rats, New Zealand Veterinary Journal, 40, pp 24–27. Rodrigo S, Sinclair M, Forbes A, Cunliffe D & Leder K (2011): Drinking Rainwater: A Double-Blinded, Randomized Controlled Study of Water Treatment Filters and Gastroenteritis Incidence, American Journal of Public Health, 101, pp 842–847. Sidhu JPS, Hannah J & Toze S (2008): Survival of Enteric Microorganisms on Grass Surfaces Irrigated with Treated Effluent. Journal of Water and Health, 6, pp 255–262. Sidhu JPS & Toze S (2012): Assessment of Pathogen Survival Potential During Managed Aquifer Recharge with Diffusion Chambers, Journal of Applied Microbiology, 112, pp 693–700. Simmons G, Hope V, Lewis G, Whitmore J & Wanzhen G (2001): Contamination of Potable Roof-Collected Rainwater in Auckland, New Zealand, Water Research, 35, pp 1518–1524. Sinton LW, Hall CH, Lynch PA & Davies-Colley RJ (2002): Sunlight Inactivation of Fecal Bacteria and Bacteriophages from Waste Stabilization Pond Effluent in Fresh and Saline Waters, Applied and Environmental Microbiology, 68, pp 1122–1131. Ward RL, Yeager JG & Ashley CS (1981): Response of Bacteria in Wastewater Sludge to Moisture Loss by Evaporation and Effect of Moisture Content on Bacterial Inactivation by Ionizing Radiations. Applied and Environmental Microbiology, 41, pp 1123–1127.
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For more information on this new and unique system, contact GFPS on 1300 130 149 or visit www.georgfischer.com.au
The Aerofloat design successfully met all the design requirements and is the first and only product to have undergone and passed the rigorous testing required for product Certification in accordance with the Australian Standard AS 4995–2009 (Greywater Treatment Systems for Vessels Operated on Inland Waters). There are four models and, to date, Aerofloat has installed systems on over 85 houseboats in South Australia and Victoria.
USING DAF TO TREAT PROCESS WASTEWATER Aerofloat™ uses a unique and innovative version of the well-known water treatment process called Dissolved Air Floatation (or DAF). Unlike traditional DAF systems, which use large and expensive mechanical scrapers to remove solids, Aerofloat’s patent-pending technology hydraulically raises the water level in the sealed, odourless DAF Tank, pushing the floated pollutants off the top of the tank via a pipeline into the wasteholding tank. The product was initially designed to meet the needs of the houseboat greywater treatment market, making it imperative that the unit was compact, easy to maintain, had low power requirements and was reliable. All these features had to be incorporated into a design that produced effluent that met the specified discharge requirements
Aerofloat has recently installed and commissioned its first 3500 unit for a food processing plant in South Australia. The unit is achieving results that exceed the specifications, removing up to 97% suspended solids and 97% oil and grease from the waste stream. The larger unit still features all the key elements of the smaller units including compactness, ease of maintenance, minimal power draw and, ultimately, due to its mechanical simplicity, it is much more affordable than a conventional DAF treatment plant. For more information email michael. email@example.com or visit www.aerofloat.com.au
Following its success in the houseboat market Aerofloat saw opportunities to develop a larger-capacity product to treat process wastewater from industrial and commercial/large residential operations. A decision was made to develop a system with four to five times the capacity of the largest houseboat system to treat wastes from the likes of food processing plants and for greywater treatment and reuse for larger residential and commercial properties. The concept of the Aerofloat 3500 (~treating up to 3500L per hour) received
WORLD FIRST DAF TECHNOLOGY
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WATER FEBRUARY 2013
Aerofloat’s Dissolved Air Floatation products:
• Use sealed odourless hopper PE tanks • Chemically condition in PE coils • Hydraulically remove waste float Visit us at OZWATER 2013. ICN/WaterAustralia stand -1J15
Water Business COMPACT ETHERNET RADIO MODEMS ALLOW NETWORKS TO BE BUILT UP QUICKLY Worldwide electrical connectivity and electronics giant, Weidmuller, has launched its long-haul WL Series of Ethernet radio modems. Extremely compact, the featurerich models combine sophisticated technical know-how with powerful capability to deliver excellent performance. Designed specifically for industrial use, the rugged and robust upright WL units have a very narrow footprint. Only 40mm wide, they provide user convenience while saving on space to help users build networks quickly and efficiently. The series incorporates a range of models including a 2.4GHz, 5GHz and 900MHz option. The high throughput modems provide effortless connectivity for line of sight distances from 5km up to 20km to deliver absolute reliability that meets the increasingly complex task of monitoring and controlling operational data. All models have as standard an inbuilt routing function and black/white list for
controlling traffic. Plus, a built-in signal strength tester measures both bandwidth and the signal strength between two radios. In addition, all units include dual diversity antenna connections and a choice of different antenna accessories to provide reliable wireless connectivity. Further, the digital I/O connection can be configured for either/or option. The WL Series provides remote wireless I/O mapping where up to 31 x I/O units can be daisychained to a transceiver at each end. A selection can be made on digital, analogue and combinational input and output types of I/O units.
The WL Series of Ethernet Radio Modems from Weidmuller.
The 2.4GHz model can be set up in a mesh network topology providing redundancy and greater reliability for industrial Ethernet devices. Each transceiver also has a built-in conversion for serial Modbus RTU to Modbus TCP. DIN rail-mounted and operating from 10â€“30Vdc supply, the plug and play WL
models provide easy configuration thanks to the built-in web browser and feature LED status indicators. Delivering exceptional performance, the WL Series is perfect for use in any industrial and water treatment plant, factory or mine site as well as in any remote monitoring application. For more information on the WL Series, call Weidmuller on free call 1800 739 988 or email email@example.com
DELIVERING A SUSTAINABLE FUTURE
DESIGN BUILD OPERATE MAINTAIN
Water Infrastructure Group leading the industry with the award-winning Virtual Control Room
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03 9863 3535 02 9325 1522 08 8348 1631 07 3712 3666
firstname.lastname@example.org email@example.com firstname.lastname@example.org email@example.com wigroup.com.au
February 2013 water
water Business CONTINENTAL WATER MEMBRANE SYSTEMS OFFER ADVANCED, EFFECTIVE WATER PURIFICATION Reverse osmosis technologies have extensive industry, science and community uses, while ultrafiltration technologies bring new efficiencies to many complementary processes. As water becomes an increasingly precious community and industrial resource, demand is growing for membrane technologies as a cost-effective option to deliver a large range of purification and separation needs. Reverse osmosis and ultrafiltration membrane systems from Continental Water provide efficient and easy-to operate filtration processes for applications such as production of drinking and process water, industrial processes, wastewater treatment, sewage treatment, product recovery, groundwater treatment and agricultural waste streams. “Membranes for water applications are a constantly evolving technology,” says Continental Water Managing Director Mr John Winstanley. “Extensive research is being invested in this arena and innovations are being made all the time to enhance the end quality of water treatment. “Many of the technologies’ general benefits are well known – such as energy efficiency and high purification efficiencies – but new answers are constantly emerging to specific industry issues and these are the advances of which users need to be aware. “An efficient reverse osmosis system is able to remove a broad spectrum of impurities from water. Applications are available which provide high recovery and energy efficient features. Ultrafiltration systems, meanwhile, eliminate the need for clarifiers and multimedia filters for waste
water February 2013
streams, enabling them to meet critical discharge criteria or to be further processed by wastewater recovery systems.” Reverse osmosis removes many types of large molecules and ions from solutions by applying pressure to the solution when it is on one side of a membrane. The result is that the solute is retained on the pressurised side of the membrane and the pure solvent is allowed to pass to the other side. The technology effectively removes organics, inorganics and micro-organics by approximately 98%. Preand post- filtration systems are also available to enhance the quality of the feed water to the systems and polish the water after the reverse osmosis system. A reverse osmosis system is able to remove and reject a broad spectrum of impurities from water with minimal energy use because it requires only mains water pressure and no chemicals, according to Mr Winstanley. Reverse osmosis membranes used to reduce salt levels from bore and river water achieve up to 99.5% efficiencies to produce the highest quality permeate. Applications include desalination treatments, water and wastewater applications, pump water (levels 1–3 for laboratories), drinking water purification and the food and beverage industry. Continental Water Reverse Osmosis Systems feature: • RO high-quality membrane modules • High pressure and CIP pumps • CIP tank • Process pressure gauges and flow metres • Skid mounted pre-filters • Stainless steel frame • ABS pipe work and valves • PLC controlled with option of HMI, GSM, dialler or SCADA remote monitoring
• Containerised or modular integration Continental Water’s Ultrafiltration system is fundamentally different from microfiltration and nanofiltration, except in terms of the size of the molecules involved. “Efficient ultrafiltration systems utilise membranes which can be submerged, which are back-flushable, air-scoured and, as well, feature spiral-wound UF/MF membranes. They offer superior performance for the clarification of wastewater and process water,” said Mr Winstanley. Continental Water Ultrafiltration Systems feature: • 8” x 60” high-quality hollow-fibre membranes • Feed and backflush pumps • Control valves • Process pressure gauges and flow meters • Stainless steel frame • APVC and ABS pipe work and valves • PLC controlled with option of HMI, GSM dialler or SCADA remote monitoring • Containerised or modular integration For information about Continental Water products, please email Fiona.Arakelian@ continentalwater.com.au
AIDS FOR FLOOD, PIPELINE AND DEWATERING WORK Versatile Pronal inflatable lifting cushions and pipe stoppers from Air Springs Supply can be invaluable during installation, maintenance and dewatering operations. Especially in rugged, sometimes remote and particularly muddy or sandy locations, including areas affected by recent floods, it can be difficult to provide crane access overhead for work on pipelines, or to obtain sufficient clearance and a firm foundation for pipeline lifts from beneath.
water Business stoppers can be used to seal concrete, plastic and metal pipelines carrying potable water, stormwater, wastewater and non-petroleum based solutions.
One way to provide an easy, safe and predictable lift in areas with restricted access is by Pronal’s seamless CLP lifting cushions, which can not only delicately raise pipelines, pumps and associated dewatering equipment, but also hoist all types of trucks, tracked vehicles, beams, bridge components, building components, machinery and resource development structures. Pronal’s cushions range from ultra-thin bags (just 20mm thick deflated) that can lift weights of more than 65 tonnes each, to powerful spreading cushions that can exert hundreds of tonnes of force to lift loads, separate plant and machinery components for servicing, or extract quarried material. Complementary low-pressure CPB MaxiLift cushions can be used on land and under water, offering greater strokes of up to 700mm (or 1400mm where a pair are employed). “These are superbly engineered lifting cushions developed for industrial, municipal, military and civil tasks by the French elastomer specialists Pronal,” says Air Springs Supply National Sales and Marketing Manager Mr James Maslin. “The materials involved are so tough and durable that the cushions are used to lift tanks or split rocks in quarries and mines. “In addition to the standard models – such as the workhorse 920 x 920mm square cushion – a major advantage of Pronal cushions is that they can be customengineered to particular shapes and sizes to perform particular tasks.” Complementing Pronal lifting cushions is Pronal’s family of pipe stoppers, including the Vari Plug range, which is used for for maintenance, testing and emergency tasks. Vari Plugs fit pipe diameters of 70mm– 1500mm in industrial, resources, municipal and infrastructure applications. Inflated by compressed air on remote sites, the tough, polyamide-reinforced
“These light, easily manoeuvred and easily positioned stoppers are typically employed for uses ranging from routine pipeline maintenance and testing through to emergency stopping of polluted water,” says Mr Maslin. “They might be employed to block a leakage of waste entering the surrounding environment or waterways, for example, or to provide a tight seal upstream of a pipeline fault so it can be repaired in a safe, clean and clear environment.” Vari Plugs are available with or without a flow-through bypass. In a pressure testing application, for example, a blank (non-bypass) stopper may be installed upstream in a pipe with another bypassequipped stopper downstream so liquid or gas can be pumped into the space between. Ongoing protection against contamination of waterways from spills into water and sewerage lines is provided by Pronal’s OPAP and OFR Pollu-Plug stoppers, which are permanently and unobtrusively fitted in water and sewerage lines ready for instantaneous inflation by remote triggering as soon as an emergency arises in industrial, civil and municipal applications. When pipelines are not subject to an emergency, the uninflated stopper allows normal nonpolluted contents
James Maslin demonstrates installation of a permanent anti-pollution Pollu-Plug. to pass beneath the elastomer-coated PolluPlug, which is located flat inside the top of a pipeline. It is connected by an air supply line to an all-weather control panel and nitrogen inflation cylinder, supplied by the customer and located outside the pipe. Pollu-Plugs are available in diameters of 100mm–1000mm and lengths of 450mm– 2050mm (both measurements when empty). Custom sizes can be produced on request. For more information on these products please visit www.airsprings.com.au
HYDROVAR, the modern variable speed pump drive is taking pumping to a new level of flexibility and efficiency. Call us to discuss your applications: Melbourne 03 9793 9999 Sydney 02 9671 3666 Brisbane 07 3200 6488 Email: firstname.lastname@example.org Web: www.brownbros.com.au
DELIVERING PUMPING SOLUTIONS
February 2013 water
Water Business NANOH2O RELEASES VERSION 2.0 OF ITS REVERSE OSMOSIS MEMBRANE MODELLING SOFTWARE NanoH2O Inc., manufacturer of the most efficient and cost effective reverse osmosis (RO) membranes for seawater desalination, today released version 2.0 of its Q+ Projection Software. Available for download on the company website, the software offers new modelling options such as multipass designs, chemical dosing to adjust the feed stream pH levels, brine stream recirculation and partial permeate splits. Also included is the ability to model brackish water RO elements based on data sheet specifications. Q+ version 2.0 is both PC and Mac® compatible. “Q+ is an innovative tool to illustrate the value of our QuantumFlux membranes,” said Nicholas Dyner, Vice President of Sales and Marketing for NanoH2O. “Since we first launched the software, we have received very positive feedback on its usability and functionality. In addition to our commitment to lowering the cost of desalination through innovative membrane technology, we are equally dedicated to providing our customers with leading-edge tools and support.” NanoH2O Inc. designs, develops, manufactures and markets reverse osmosis (RO) membranes that lower the cost of desalination. Based on breakthrough nanostructured materials and industryproven polymer technology, NanoH2O’s QuantumFlux membranes dramatically improve desalination energy efficiency and productivity. QuantumFlux seawater reverse osmosis (SWRO) membranes deliver the highest flux and the highest salt rejection of any SWRO membrane on the market. Certified by NSF International for the production of drinking water (Standard 61), QuantumFlux membranes are available
in standard 8-inch (20cm) diameter elements that fit easily into new and existing desalination plants. Water can be purified from a broad range of sources with improved productivity and water quality. For more details, visit www.nanoh2o.com
ROTORK ACQUIRES FAIRCHILD INDUSTRIAL PRODUCTS COMPANY Rotork is pleased to announce the acquisition of Fairchild Industrial Products Company, a manufacturer of high-precision pneumatic controls and power transmission products based in North Carolina, US. Fairchild manufactures a full range of market leading regulators, boosters, relays and transducers. The products are used in a wide variety of applications that require precision control of pneumatic devices and motion control equipment. As well as oil and gas applications the company also benefits from orders in pharmaceutical and biomedical equipment, tyre manufacturing machinery, robotics, food processing and chemical manufacturing applications. The company has offices in China and India with local presence in Mexico, Russia and Brazil. The acquisition of Fairchild is in line with Rotork’s strategy of strengthening its presence in the global flow control market, as part of which the Group also announces the creation of a new division, Rotork Instruments. Rotork Instruments will focus on developing further opportunities in the flow control market; in particular, products associated with flow and pressure control and diagnostic and information gathering technology. Fairchild will be the first company within the Rotork Instruments division. Commenting on the acquisition, Rotork Group Chief Executive, Peter France, said: “The acquisition of Fairchild will strengthen our presence in the global flow control market and, in forming the basis of the new
division, Rotork Instruments, will broaden the scope of the Group’s activities.” Fairchild’s sole distributor for the Australian Sales Territory is Rotork Australia, which has five regional offices. These offices will support Fairchild’s sales and support function. For more information please go to www.rotork.com
US and Mexico Sign Historic Agreement US and Mexican commissioners of a bi-national agency that manages water crossing the border have signed Minute 319, an amendment to the 1944 treaty that allocates Colorado River water to Mexico. This new agreement for the first time guarantees that some water will flow in the usually dry Colorado River channel that marks the boundary between Baja California and Arizona. “We’ve been working for more than 15 years to get water back in the river; this remarkable achievement is a huge step forward for the embattled Colorado River delta,” said Michael Cohen, senior associate at the Pacific Institute and author of major research on the sustainable use of the Colorado River water. “It is incredibly satisfying to think that the dedicated efforts of so many people, over so many years, have led to this historic moment. It is a long overdue end to the incredibly destructive 20th century notion that not a drop should be left instream.” In addition to ushering in a new era of cooperation between US and Mexican stakeholders, the new agreement signals a milestone in the two countries’ recognition of the environmental value of water left to flow in the Colorado River. Legally dedicating a significant volume of water to nature helps to strike a long-overdue balance between water for agriculture, cities and the delta environment.
Advertisers Index Acromet 46 Aerofloat 96 AIRVAC 19 Aquatec-Maxcon 11 AWMA 30 Bintech 51 Brown Brothers 99 Campbell Scientific 25 Codesafe 94 Comdain IFC
water February 2013
Georg Fischer 14 Hach Pacific 20 IDE OBC ITS Trenchless 15 James Cummings 76 Merck 93 NOV Mono Pumps 61 Pentair 7 Quantum Filtration 98 State Water 21
Sulzer 23 Sydney Water 24 Tenix 2,3 Trility 22 Water Infrastructure Group 97 Weidmuller 9 Xylem 13 Xylem 17 Zetco IBC
The new force in PE
Winner of ‘Desalination Company of the Year 2011’ GWI award, IDE presents advanced and flexible small to large-scale desalination solutions
Proven Track Record: 400 Plants. 40 Countries. 4 Decades. • World’s largest thermal and membrane desalination plants • Lowest cost of desalinated water in BOT projects • Innovative water treatment technologies • High expertise in small to mega-sized desalination projects
This issue looks at "Why we need innovation in water", plus you’ll find a range of articles and technical papers on topics such as Wastewate...
Published on Feb 22, 2013
This issue looks at "Why we need innovation in water", plus you’ll find a range of articles and technical papers on topics such as Wastewate...