Water Journal December 2011 by australianwater

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Volume 38 No 8 DECEMBER 2011 RRP $16.95 inc. GST

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

THE RIGHT TO A FAIR SHARE

PRINT POST APPROVED PP 225517/00008

Phil Duncan talks about Indigenous water rights and the Murray-Darling Basin – see page 40.

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Journal of the Australian Water Association ISSN 0310-0367

Volume 38 No 8 December 2011

contents REGULAR FEATURES From the AWA President

That Was The Year That Was

From the AWA Chief Executive The View From The Top My Point of View Trends In Wastewater Management

Lucia Cade

Tom Mollenkopf

James Barnard

Crosscurrent

Carved trees are like a history book for Indigenous peoples. See page 40.

Industry News

AWA Young Water Professionals

AWA News

SPECIAL FEATURES Assessing Australian Water Reform An edited extract of National Water Commission Chair Chloe Munroe’s speech

The Right to a Fair Share An extract of Phil Duncan’s speech on Indigenous water rights at Riversymposium

Productivity Commission: Final Report An outline of the key findings of the inquiry

Andrew Speers

CONFERENCE REPORTS AWA’s 2nd National Water Leadership Summit Keynote speakers and highlights Andrew Speers

15th International Desalination Association Congress A comprehensive report Diane Wiesner

The Value of Rivers Discussions from the 14th International Riversymposium

AWA CONTACT DETAILS Australian Water Association ABN 78 096 035 773 Level 6, 655 Pacific Hwy, PO Box 222, St Leonards NSW 1590 Tel: +61 2 9436 0055 Fax: +61 2 9436 0155 Email: info@awa.asn.au Web: www.awa.asn.au

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

COPYRIGHT AWA Water Journal is subject to copyright and may not be reproduced in any format without written permission of the AWA. To seek permission to reproduce Water Journal materials, send your request to journal@awa.asn.au WATER JOURNAL MISSION STATEMENT ‘To provide a journal that interests and informs on water matters, Australian and international, covering technological, environmental, economic and social aspects, and to provide a repository of useful refereed papers.’ PUBLISH DATES Water Journal is published eight times per year: March, April, May, July, August, September, November and December.

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

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

Delegates at the 15th IDA Conference in Perth. See page 48.

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

UPCOMING TOPICS MARCh 2012 – Water in Mining; Water Recycling; Sewer Processes; Smart Water Systems/Metering; Pipelines, Controllers, Leak Detection; Rainwater Tank Technology; Environmental Impacts. APRIL 2012 – Catchment Management; Aquifer Recharge; Stormwater Use; Automation & Telemetry. MAY 2012 – Enviro 12 Preview; Education & Skilling, WICD; Safety, Pipeline Cleaning & Maintenance.

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

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

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DECEMBER 2011 1

Journal of the Australian Water Association ISSN 0310-0367

Volume 38 No 8 December 2011

contents

PHOTO: © PERMEATE PARTNERS 2011

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The distributed recycled water system at Pennant hills Golf Club. See page 69.

TEChNICAL FEATURES (

A septic hauler tank unloading at Shobak in Morocco. See page 77.

INDICATES THE PAPER HAS BEEN REFEREED)

WATER RESOURCES Life Cycle Assessment of the Gold Coast Urban Water System The challenge of achieving a balance between opposing environmental impacts

D de Haas, J Lane & P Lant

R Fabris et al.

R Watson

PM Geary & JH Whitehead

T Young et al.

J O’Toole

B Bolto & M Hoang

WATER TREATMENT Effective Water Quality Monitoring for Drinking Water Treatment Plants Increasing regulation of undesirable by-products has raised awareness of the need for monitoring DOC WASTEWATER SYSTEMS Wastewater Systems: Decentralised or Distributed? A review of terms used in the water industry SMALL WASTEWATER SYSTEMS Water Quality Impacts on Estuarine Aquaculture: A Review Standard designs for on-site wastewater systems have been developed and impacts reduced Reliable Low Technology for Pollution Control in Semi-Rural Morocco and Jordan Beneﬁcial products include irrigation water, reeds and dried biosolids for soil amendment MICROBIOLOGY Monitoring Microbiology Wisely A user’s guide to monitoring program design and collection of exposure data CONTAMINANTS OF CONCERN Water Reuse: Removal of Trace Organic Compounds A comprehensive review shows that no single treatment can remove all micropollutants WATER BUSINESS New Products and Business Information

Advertisers’ Index

OUR COVER As recognised by the UN’s Declaration on the Rights of Indigenous Peoples, Australian Aborigines have a right to their traditional lands, water and resources. See page 40 for an extract of the speech by Phil Duncan, Chair of the First Peoples’ Water Engagement Council, at Riversymposium.

DECEMBER 2011

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from the president

That Was the Year That Was … Lucia Cade – AWA President What a year of change and contrast we have experienced in 2011. Significant rain, flood and cyclone damage affected northern Australia, with lives lost, crops demolished and mines incapacitated. Heavy rains and floods up and down the east coast and inland resulted in enormous crop and property losses and damage throughout NSW and northern Victoria. Ongoing drought and bushfires are still impacting on Perth and surrounds. East coast dams are full and west coast dams are still falling. Peta Maddy, AWA Victorian Branch President, in her introduction to the Victorian Water Summit which was held to launch National Water Week in Victoria, commented: “… it seems that everything has changed in the space of a single year … we have had significant changes in our rainfall, a change of government and surely a change in community attitudes to water management”. This is reflected around the country. Community attitudes are certainly changing. As urban people are paying more for their water supplies they are becoming more vocal in their objection to rising prices. A drastic example of the effect of this type of backlash was the recent final confirmation of the “disestablishment” of Allconnex, one of the three distributor-retailers created in South-East Queensland in the recent industry restructure. A hugely effective community campaign, which blamed all price rises on Allconnex, culminated in Gold Coast Council voting to take its water services back into Council. Allconnex is now immersed in a deconstruction planning process as it transitions people and assets back to their councils of origin. Community concerns about water issues are impacting the potentially lucrative coal seam gas industry in Queensland, with issues both around the impact on groundwater of the gas extraction process, and the challenge of treatment

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and beneficial use of enormous quantities of water. Media headlines have been almost universally in favour of reporting community and farmers’ concerns. The good news to my mind is that there is acknowledgement from industry leaders, ministers and policy makers that there is a need to continue to focus on how we change our industry to meet the challenges of climate change, secure our water supplies, protect our water resources and allocate our water to ensure our ongoing health and prosperity. The Hon. Peter Walsh, Minister for Water in Victoria, told the Victorian water industry at the Victorian AWA Awards night in October that while we do have some breathing space, now is not the time to take the foot off the accelerator as we plan how to better manage, invest in and allocate our water resources. Speaking of awards, around the country there is acknowledgement through the AWA Awards program of the excellence and innovation of people and projects in the industry. We have so many bright, passionate and dedicated people in our organisations creating truly inspiring solutions to our water challenges. All the State Award winners will be in the running for the National Awards, which will be announced at Ozwater’12 in Sydney next May. The event coincides with AWA’s 50th Birthday, so make sure you book it into your 2012 calendar now! I wish you all a peaceful, happy and safe Christmas and holiday season. And be sure to recharge your batteries, because while 2011 has been a big year, I don’t believe there is anything to suggest that 2012 will be any quieter!

regular features

from the chief executive

The View from the Top Tom Mollenkopf – AWA Chief Executive In my dreams, I may imagine that my periodic musings in this column are received by readers as a view ‘from the top’; back on earth, however, the reality is a little more humble. So just to be clear, the title of my column this issue actually refers to the recent AWA/Deloitte State of the Water Sector Report (subtitled The View From the Top). The 2011 final report builds on the earlier quantitative research that was published in a preliminary report. It has an added richness from qualitative observations and analysis that come from interviews with over 20 water sector leaders from around the country. There are some critical messages that emerge from these discussions. I am not sure whether to take comfort from the fact that two of my favourite themes rate a mention: 1) the need to continue with reforms in both the urban and rural sectors; and 2) the concern that rain in the eastern states is reducing the focus on water as a policy priority. Other key issues covered include sustainability, the need for good governance (free of political interference and with independent skills based boards), competition and the role of markets. It makes for stimulating reading and I commend the full report to you. It’s available for download from the AWA website (www.awa.asn.au) under the News & Advocacy tag. The AWA/Deloitte report was launched at our second annual National Water Leadership Summit held in Canberra early in November. We were fortunate to again have an outstanding series of speakers. Federal Minister the Hon. Tony Burke opened proceedings with a timely overview of the Murray-Darling Basin Plan. We are all only too well aware of the difficulties associated with the many competing demands of the Plan. Certainly it has already drawn its fair share of criticism, with the original draft substantially reviewed under the guidance of a new CEO and a new Chair. The Plan is expected to be released at the end of November and a 20-week consultation period will follow. AWA is in agreement with the Minister; we absolutely must take the opportunity to lock in a long-term sustainable plan for the Basin. The rains of the past 12 months have provided some breathing space, but they have not changed the underlying volatility in inflows to the basin. The comment that not everyone will be happy with the outcome of the Plan is a sad reality that we must all accept.

My appreciation also goes to Kim Wood, who was our dinner speaker at the Summit. Kim is the outgoing Managing Director of Allconnex, the water utility serving Gold Coast, Redlands and Logan municipalities in Queensland. His honest appraisal of the trials and tribulations of the SEQ reform process and its application on the Gold Coast drew universal empathy from the audience and his candid speech provided much food for thought. Happily, Kim’s experience and talent is not lost to the industry as he is heading to Newcastle to head up Hunter Water. Finally, this edition of Water Journal again features a wonderfully full complement of technical articles and policy matters, as well as details of AWA programs, activities and events. One article in particular, however, touches on a topic that has been an abiding interest of mine. In September, Phil Duncan, Chair of the National Water Commission’s First Peoples’ Water Engagement Council, spoke at Riversymposium in Brisbane. An edited version of his passionate presentation regarding indigenous peoples’ relationship with, interests in and rights to water appears on page 40. A little over 12 months ago, AWA touched on this subject when we published a beautiful depiction of a water ‘dreaming’ by Shorty Jangala Robertson, accompanied by a short feature article (see Water Journal, August 2010, cover and page 32). The critical role that water and environmental flows play in supporting our eco-systems is increasingly well accepted. We are also becoming increasingly aware of water’s direct and indirect role in maintaining viable rural and regional communities. There remains, however, both the opportunity and the need to appreciate the deeper association that water has had for indigenous peoples over millennia, not just practically (including economically), but also spiritually. A better comprehension of these issues will not only lead to greater respect for the stewardship of our water resources by our first peoples, but also an enhanced understanding of their culture and art, and better water management practices both now and into the future.

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my point of view

Trends in Wastewater Treatment James L Barnard, Global Practice & Technology Leader, Black & Veatch James Barnard has worked in the water industry for 53 years, including stints at the Universities of Texas and Vanderbilt for postgraduate studies, after which he returned to his home country of South Africa and began research into nutrient removal. He has been involved in the design and operation of more than 100 treatment plants and taught courses in BNR at the University of Queensland Winter School for 10 years. He was recently awarded the Lee Kuan Yew Prize during the 2011 Singapore Water Week. Anyone who has been active in the field of wastewater treatment for some time will have seen many new trends. Some of us “oldies” have seen some trends in the technology that come with great fanfare, linger on for some time and then mostly fade away or find a niche market. Sometimes they undergo a transformation and a revival. I count myself fortunate to have benefitted from one such international trend that was initially viewed as a fad – namely the concept of discarding biological treatment in favour of physical/chemical treatment. The logic was that biological processes were unreliable, not as efficient and generally passé. This trend was reinforced by the need to remove nutrients. Johannesburg is situated on the continental divide in what is now the Gauteng Province in South Africa, with Pretoria 50kms to the north and 300m lower. Due to the geography of Johannesburg and its surrounds, all of the treated effluents were discharged to reservoirs, which resulted in severe eutrophication. One concept that was promoted in the early ’70s was to treat the settled sewage with lime to a pH of 12, which removed the phosphorus and nasty compounds such as heavy metals, stripped the ammonia to the atmosphere, with breakpoint chlorination for the removal of residual ammonia, followed by granular carbon for removal of carbon compounds. This was the concept that was also developed for water reclamation for the City of Windhoek in Namibia. Biological nitrification and denitrification was already wellestablished at this point, but as two separate stages in which organic carbon, usually in the form of methanol, was added to the denitrification stage. After completing studies at Vanderbilt University, I returned to the National Institute for Water Research in Pretoria South Africa and was shocked to see the deterioration in reservoirs as a result of eutrophication. I saw an opportunity to use the carbon in the feed for denitrification in a one-sludge system that led to the development of the Bardenpho process as well as the Phoredox (AO) process. Problems that developed with physical-chemical treatment related to the difficulty of using lime and the deposits that

6 DECEMBER 2011 water

formed during and after recarbonation. In addition, the organic carbon remaining after lime or chemical treatment such as volatile fatty acids did not absorb well on GAC; rather, the latter became a medium for adsorption of anaerobic bacteria that feasted on the readily biodegradable COD.

Back in Style Today, biological treatment again forms the heart of used-water treatment with the judicial use of chemicals for optimising treatment, or with membranes for effective liquid/ solids separation. The superiority of biological nitrogen removal is well established, be it on attached growth systems or in a suspended growth environment. The main disadvantage of biological nitrogen removal is that it is still energy intensive, requiring energy for aeration to achieve nitrification and energy in the form of a carbon source for denitrification. Recovery of resources from wastewater is now a popular topic, but since nitrogen is not in short supply, recovery of nitrogen must compete in cost with that of fixing it from the atmosphere by the Haber-Bosch process. Exciting new developments such as the Anammox process, or granular activated sludge, hold the promise of nitrogen reduction at much lower energy cost. The Anammox process short-circuits the nitrification/denitrification loop, using less than half the energy and little in the way of carbon, freeing up internal carbon sources for possible energy generation. Based on present research trends, I expect to see the Anammox process being applied in both side-stream and main-stream applications. Granular activated sludge holds the promise of achieving nitrification and denitrification, as well as phosphorus removal in one basin. In addition, the rapid settling rates would eliminate final clarifiers. There are already two full-scale plants in the world. Biological phosphorus removal is restricted to the suspended growth systems and has already seen some swings in popularity. After the initial excitement there was a sense of resignation, as was put into words by the famous Professor Poul Harremoes: “Biological phosphorus removal is something you design for, hope for and add chemicals if it does not work”. But these sentiments were a result of a lack of understanding of the biological mechanism, and the need for sufficient fuel in the form of volatile fatty acids, a field in which much progress has been made, even while we learn more about it each day. The marketplace finally dictated the direction and we see more biological plants being constructed and operated today. As an example, Severn-Trent Water in the UK at first decided against biological phosphorus removal, but as the cost of chemicals

regular features

my point of view

Westbank process at Wilson Creek in Texas. rose a new interest in the development of side-stream fermentation of return-activated sludge convinced the company to convert all their plants to mainly biological operation, with an estimated saving of £4m per annum. Phosphorus removal to very low levels requires that chemicals be used for polishing, but even then substantial savings by the combination of biological and chemical systems are possible. In a small plant in the state of Colorado, the consumption of chemicals was reduced to a molar ratio of Alum to P of around 0.4, by maximising biological phosphorus removal for reducing the influent phosphorus from 9mg/l to an average of 0.025mg/l. While the wastewater characteristics were not favourable for BPR, some in-plant fermentation of mixed liquor supplied sufficient volatile fatty acids to reduce the final clarifier effluent TP to less than 0.5mg/l. A recent study in a ski resort in the same state showed that it was possible to reduce orthophosphorus to less than 0.03mg/l by using a similar method.

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The Question of Sustainability An exciting concept is the development of fuel cells in which the biological reactions are driven by using a cathode as electron acceptor instead of oxygen, thereby generating energy rather than using energy. However, in spite of the fact that aeration is one of the most important energy users at a treatment plant, the actual energy consumption of a welldesigned and operating biological nutrient removal plant is less than 35kWh per person per year – and while great strides have been made in fuel cells, much more research breakthroughs will be necessary to justify the capital cost for saving that energy. The new catch phrase is “sustainability”, but it is not always clear what the term means, even though definitions abound. It is used, for example, when designing a plant to produce ultralow nitrogen or phosphorus at huge cost and carbon footprint. A question was asked in a recent workshop: “Should sustainability not start with the regulators?” What is the point of driving down effluent phosphorus to less than 0.01mg/l at great cost when the non-point sources form a large component of the phosphorus discharged to a lake? Should the phosphorus limit not be set at a percentage of the diffused sources? Why spend massive amounts of money on reducing the phosphorus at point sources to below, say, 2–5% of that of the diffused sources? And why remove nitrates when in many instances it is beneficial to the health of the reservoir?

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When a reservoir has been shown to be phosphorus limiting and it gets phosphorus from diffused sources, discharging some nitrates may prevent the growth of nitrogen-fixing cyanobacter with their associated toxins, while preventing the release of phosphorus in the hypolimnion. These are questions that need serious consideration if we don’t want to make a mockery of sustainability studies.

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International The Australian Government has flown a large desalination unit to drought-stricken Tuvalu; the unit is capable of turning 50,000 litres of seawater a day into clean drinking water. Australia is also working with authorities to have existing desalination units on Funafuti and Nanumanga Islands in full operation.

National The Productivity Commission Report on Australia’s urban water sector has been released. The report follows a year-long inquiry established to consider the case for further reform in the sector. Parliamentary Secretary for Sustainability and Urban Water, Senator Don Farrell, said the urban water sector plays an important role in providing the vast majority of drinking water, recycled water and wastewater services in Australia.

The National Health and Medical Research Council has released the 2011 version of Australian Drinking Water Guidelines (ADWG). The guidelines provide the Australian community and the water supply industry with guidance on what constitutes good quality drinking water. The upgraded Community Water Planner, a web-based tool designed to assist small communities to develop drinking water management plans, will be released at the same time. The CWP covers microbial, physical, chemical and radiological risks to water supply.

The Australian Water Recycling Centre of Excellence has announced up to $2 million of funding is now available for applied and strategic research projects that quantitatively demonstrate and/or enhance the social, economic or environmental value of water recycling in Australia. If you are interested in submitting an Expression of Interest, visit the Centre’s website.

The COAG Reform Council has issued its second annual report on the Water Management Partnerships. The report claims that progress on water-saving investment projects in the Basin has been too slow, with only one of 13 state-led projects having been completed. The Council said the risk that timeframes for delivering the Plan would be further extended would affect the Commonwealth’s ability to deliver the proposed plan in 2012, as well as the Basin states’ ability to meet a range of associated water planning milestones. National Water Commission Chair Ms Chloe Munro said the COAG Reform Council’s findings are consistent with the Commission’s recent assessment of water reform progress under the National Water Initiative.

Australia’s first National Water Account has been released. Parliamentary Secretary for Sustainability and Urban Water, Senator Don Farrell, said the Bureau of Meteorology’s delivery of the National Water Account was a landmark achievement. Eight regions were included: Adelaide, Canberra, Melbourne, Murray– Darling Basin, Ord, Perth, South-East Queensland and Sydney.

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The MDBA has launched a blog for open online conversations where anyone can ask questions and discuss the draft Basin Plan. The blog is available at www.freeflow.mdba.gov.au

The National Farmers’ Federation (NFF) is calling on the Murray-Darling Basin Authority (MDBA) to demonstrate how the draft Murray-Darling Basin Plan achieves greater balance than last year’s Guide. NFF President, Jock Laurie, said: “While we would welcome a mid-term review and the ability to reduce Sustainable Diversion Limits, on face value, what we’re seeing from the MDBA’s ‘current thinking’ on the draft Plan is that the actual figures do not look much different.”

Management of Commonwealth environmental water requires ongoing assessment of options, including whether water should be used within the current year, carried over for use in future years, or whether trade should occur (disposal or acquisition). Accordingly, DSEWPC has issued a discussion paper: ‘Trading of Commonwealth environmental water’. Responses to the paper are sought by 27 April 2012 and can be sent to: ewater@environment.gov.au

Innovation Minister Senator Kim Carr has launched ACA Research’s and waterAUSTRALIA’s Water Industry Capability Report. Mr Carr said the unique approach of Australian firms to water policy, management, distribution and efficiency had been seized on globally. The report is based on a survey of more than 430 water firms, including manufacturers, technical support service providers, consultants, irrigators and infrastructure operators. It shows water industry businesses are turning over more than $4.2 billion annually and employing over 25,000 people.

Queensland The direct management of water and wastewater services will be returned to the Gold Coast, Logan and Redland Councils under new legislation introduced into Queensland Parliament. Minister for Water Utilities Stephen Robertson said changes to the SEQ Water (Distribution and Retail) Restructuring Act (DR Act) would formalise the three councils’ decisions to disband distributorretailer Allconnex and take back their water businesses.

The Queensland Minister for Energy and Water Utilities is encouraging irrigators to provide feedback on a draft report released by the Queensland Competition Authority on SunWater›s new five-year irrigation price path to commence 1 July next year. Mr Robertson said this is the first review of SunWater›s irrigation pricing by Queensland›s independent economic regulator.

New South Wales Sydney Water has prepared an Environmental Assessment (EA) to assess the impact of constructing and operating water and wastewater infrastructure to service the North West Growth Centre precincts of Box Hill, Box Hill Industrial and Schofields. Sydney Water Manager for Urban Growth, Sharon Davies, said the EA will be displayed at local community sites.

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DECEMBER 2011 9

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crosscurrent The water-sharing plans for Intersecting Streams Unregulated and Alluvial and NSW Great Artesian Basin Shallow Groundwater has commenced. These plans include rules for protecting the environment, water extractions, managing license holders’ water accounts, and water trading in the plan area.

The WA Department of Water has released two reports commissioned by the Swan River Trust. The reports, produced during the second stage of the Trust’s non-nutrient contaminants program, focus on the ecological impacts of contaminants found in the estuary at Claisebrook and Bull Creek.

Owners of certain works, such as dams that exceed their maximum harvestable right capacity, constructed before 1 January 1999 have been able to apply for a water supply work approval and an access license to enable them to become licensed and recognised under the Water Management Act 2000 licensing regime. This amnesty will end on 31 December 2011.

The Water Corporation’s 2010/11 Drinking Water Quality Annual Report shows that drinking water in Western Australia has met all health targets set by the Department of Health. The annual report is published each year and provides detailed water quality information in an open and straightforward manner.

The $7 million Pipeline NSW program will benefit both the environment and farmers, says the NSW Office of Water. The program will deliver dual benefits: saving more water for the environment and providing NSW farmers with a more secure, better quality supply of stock and domestic water.

Goulburn residents will benefit from a secure water supply in times of drought following the completion of the emergency Wingecarribee to Goulburn pipeline. The 81km underground pipeline links the Goulburn water supply system to the Sydney Catchment Authority’s water supply at Wingecarribee Reservoir.

Sydney Water has issued a warning for its customers to be on the lookout for scams where people present as Sydney Water representatives offering free shower head replacements. Customers report they have been targeted by these scams through phone calls and door knocking.

One of Sydney’s most polluted beaches is being cleaned up, with Sydney Water and Randwick City Council starting work on a $2M project at Malabar Beach. Under the joint project, two stormwater pipes that discharge into the beach will be diverted into a Sydney Water pipe that flows out at the old cliff face outfall, well away from the swimming area.

A new stormwater harvesting and reuse project in Geraldton will save more than 745 million litres of drinking water each year by 2014. Senator Don Farrell, Parliamentary Secretary for Sustainability and Urban Water, has announced $3 million in Australian Government funding for the City of Greater Geraldton’s Stormwater Harvesting and Efficiency Project. The City has agreed to match the Australian Government’s contribution.

Work is due to begin to provide a vital wastewater service to a growing area of Port Hedland as part of the WA Government’s Infill Sewerage Program. 250 residential blocks will benefit from a connection to the Water Corporation’s wastewater scheme.

The Water Corporation has commenced works on a second wastewater pipeline along Millstream Road to improve wastewater disposal and cater for future growth in Karratha. The project, worth $3.5 million, involves construction of 2.65 kilometres of main and associated infrastructure and will be used to transfer increased wastewater flows from Karratha to the treatment plants.

Western Australia

The WA Water Minister has announced the finalists for the WA Water Awards 2011. The State Government’s awards program aims to showcase WA’s leaders in innovation, leadership and achievement across a range of water industry activities. Entries had been received this year from throughout the state, from the Pilbara to Perth and Mandurah to Margaret River. The WA Water Awards are managed and organised by AWA.

A Murdoch University masters student is investigating whether setting up a pollution trading scheme will help alleviate water quality problems in the Peel-Harvey Catchment. Ophelia Cowell said market-based approaches had been successfully used to manage water pollution in other areas of Australia and she would be working closely with the Peel Harvey Catchment Council and other groups to examine the feasibility of whether such schemes would work in the region.

Three more Western Australian local governments have committed to better use of bore water on recreational spaces and scheme water on council facilities after achieving Waterwise Council status. Coinciding with the National Water Week theme of ‘Healthy Catchments Healthy Communities’, Water Minister Bill Marmion said the Town of Cottesloe and shires of Mundaring and Ashburton had joined 14 other councils endorsed as Waterwise.

Water Corporation has confirmed its commitment to employees of Swan Water Services that their employment continues unchanged into a new Alliance partnership that was announced recently. The Alliance will take over the provision of operations and maintenance services for the water and wastewater networks across Perth from February next year.

The first stage of a trial to install and monitor new smart water meters at 24 households in Kalgoorlie-Boulder has been successfully completed, paving the way for the second phase of the water-saving program. WA Water Minister Bill Marmion said he was impressed with the new meters that were assisting Water Corporation customers to save water and detect leaks.

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Victoria

Member News

South East Water, Melbourne Water and Southern Rural Water, in consultation with a 25 member Stakeholder Reference Group, have developed Water Initiatives for 2050: an Integrated Water Management Strategy for Melbourne’s south east, to enable the region to thrive into the future. The strategy presents a range of options to determine the most sustainable mix of water solutions including stormwater, recycled water, greywater and groundwater.

SKM has appointed of Mark Thorn as its new Global Service Line Leader for Geotechnical Engineering.

River, stream and creek water quality information collected by Victorian Waterwatch volunteers is now available to the public following the launch of the new online Waterwatch Victoria Data Management System. Go to www.water.vic.gov.au to view.

A $650 million project to boost sewerage capacity in Melbourne’s north and protect the health of local waterways has been completed. Water Minister Peter Walsh said the project, which has come in $135 million under budget and six months ahead of schedule, provided significant public health and environmental benefits, virtually eliminating raw sewerage spills into Moonee Ponds and Merri creeks during extreme wet weather.

Kevin Devlin has been appointed the new Alliance Manager for Melbourne Water’s $650 million Water Resources Alliance, where he will lead the delivery of essential water and sewerage infrastructure works on behalf of the program partners, Melbourne Water, Baulderstone, United Group, Sinclair Knight Merz, MWH and Becca.

Water Services Association of Australia (WSAA) has announced the appointment of Sue Murphy, Chief Executive Officer of the Water Corporation of WA, as the new Chair of the WSAA Board. Sue takes over from the outgoing Chair, Kevin Young, Managing Director of Sydney Water.

CH2M Hill has welcomed Halcrow to its business. They now have a workforce of almost 30,000 employees with approximately 11,000 employees outside the United States.

Victorian Water Minister Peter Walsh has released a comprehensive water management plan for Victoria’s western region. The Gippsland Region Sustainable Water Strategy maps out the region’s water resources and the challenges and opportunities facing all water users over the next 50 years.

Black & Veatch has promoted James Currie to Director, Client Services, Australia to help lead and grow the company’s global water business in Australia. Currie has led the company’s Melbourne office since 2008. He now takes on a national role for the firm’s professional services business.

The Australian and Victorian Governments have reached a new agreement to deliver the nation’s largest irrigation infrastructure renewal project. The agreement will help restore the Murray River to health and deliver a world-class irrigation system for northern Victoria’s food producers.

TRILITY Pty Ltd has announced that it has acquired full ownership of the Macarthur and Yan Yean water filtration plants in New South Wales and Victoria respectively.

Minister Walsh has announced the appointments of Malcolm Eccles as a new director to the board of Gippsland Water and Russel Worland and Frank Zeigler to the board of Wannon Water.

National Water Commission Chair Ms Chloe Munro has congratulated Mr James Cameron on his appointment as the Chief Executive Officer of the National Water Commission. Mr Cameron has been acting in the role since the retirement of inaugural Chair and CEO, Mr Ken Matthews, in October 2010.

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crosscurrent AECOM has appointed a flood mitigation specialist to the role of Technical Director of Water Resources in Australia and New Zealand. Joe Chapman has relocated to Brisbane from the United States to develop floodplain management and surface-water modelling for AECOM’s Australia and New Zealand water business.

Indesco Consulting Engineers has appointed Dr Mark Henry Rubarenzya to lead its Water Resources and Stormwater group. Mark Henry is a civil and water resources engineer with professional experience in water resources primarily in Australia, Eastern Africa, and Europe. Melbourne Water has been named the inaugural Organisation of the Year in a prestigious award honouring excellence in involving the public in decisions that impact their lives.

Ms Eva Skira has been appointed to the Water Corporation Board for a term until December 31, 2013. Ms Skira has 17 years’ experience as chair and board member at a number of Australian organisations and has a background in banking, stockbroking and finance.

GWMWater has won the Victorian Engineers Australia Award for Excellence in the category for Environment for the delivery of the Wimmera Mallee Pipeline Project. The award was announced at the Awards Ceremony in September.

AWA Life Member Lance Bowen sadly passed away in October. Mr Bowen had a long and distinguished career as a scientist, specialising in the areas of water chemistry and bacteriology. Mr Bowen joined Sydney Water (which was then known as the Metropolitian Water Sewerage and Drainage Board) in 1951 and rose to the position of Principal Chemist in 1979. He remained Head of Discipline until his retirement in 1987. Mr Bowen played a key role in the joint working group of the Australian Water Resources Council and the NHMRC, which drew up the 1987 guidelines for drinking water quality in Australia.

AQUAPHEMERA The Productivity Commission Report on Australia’s urban water sector was provided to the Australian Government in October (www.pc.gov.au/urbanwater). This report has significant improvements compared with previous reports and even with the discussion paper for this review. Recommendations are welcome for Real Options analysis; adaptive planning done by utilities; full cost recovery; revenue caps and scarcity pricing; regulators avoiding conflicting objectives as well as using light-handed regulation; utilities operating under the Corporations Act with Directors being appointed (by Governments) on merit; and Governments setting clear objectives, including utilities providing services in an economically efficient manner to maximise net benefits to the community. However, a few recommendations don’t follow the objectives above: 1. Water restrictions reserved for emergency situations – these were intended for once in 20 years in many jurisdictions, so is an emergency once in 100 or less? To provide water security to that level would be massively uneconomic. 2. Use a menu of service (tariff) options – while fine in theory and for “non-essential” services, there is a lot of work needed (and currently in progress) before this can be considered as even a possible offset for restrictions. 3. Two-part tariffs – a fixed and single volumetric price totally ignores the essential nature of water and the demand management value of a second-tier volumetric price. The price elasticity of water is greater for garden use than internal use and, hence, that second tier price has a much greater impact on demand and allows for more effective scarcity pricing. 4. Charge tenants directly – this would be equitable and send appropriate usage messages to those consumers, but can it be done economically and efficiently? Overall, an excellent report, and when considered by COAG for implementation, hopefully they will be consistent in its application. – Ross Knee

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DECEMBER 2011 13

industry news New Publication on Water Law

Table 2. Top 10 most expensive cities (combined water and wastewater tariff per kilolitre).

A new book, Australian Water Law, offers practical, up-to-date guidance on the critical issues of ownership, control and use of water as a resource. Kate Stoeckel, Romany Webb and Luke Woodward apply their legal experience in matters involving water rights as well as regulation of the water and sewerage industry, while Amy Hankinson offers her expertise in environmental law and water management. Legal, regulatory, policy and technical issues are considered. Lawyers working in water and environmental law, and non-legal professionals involved in water resource management and planning, will be apprised of the legislative instruments that control water resources in Australia, as well as the nature of water rights and their impact. Australian Water Law provides a concise and practical legal treatment of water planning and management, following many years of development and change in the law. Go to www.thomsonreuters.com.au and ‘Search’ for more information.

Global Water Tariff Survey The September issue of Water Journal reported on water pricing trends globally. Since then the 2011 Global Water Tariff Survey has been released by Global Water Intelligence. This year’s survey shows that global water prices have continued to increase at a rate generally above inflation in the countries surveyed (although it must be acknowledged that rates of inflation are high in some countries; water tariffs in Turkey, for example, are adjusted monthly in response to the inflation rate). On average, global water tariffs have risen 6.8% in constant exchange rate terms. The city with the largest percentage increase in rates was Memphis, US, with an increase of 93.6% to $US1.52/kl in the combined water and wastewater tariff, largely driven by the need to comply with water quality guidelines. In our neighbourhood, the city with the greatest reduction in water tariff is Auckland, with a fall of 36.3% producing an overall reduction in the combined water/wastewater tariff of -4.4% (to $US4.63) Australia is now one of the higher priced countries, second only to Denmark. Since the previous Tariff Survey, water prices in the basket of five Australian cities surveyed in 2011 increased by 11.5%. A selection of developed country average combined water tariffs is shown in Table 1.

Table 1. Most expensive cities (combined water and wastewater tariff per kilolitre). Country

Average water tariff

Average wastewater tariff

Average combined tariff

% Increase

No. of cities included

Denmark

$4.32

$4.52

$8.83

0.1%

Australia

$3.14

$2.65

$5.78

11.5%

Germany

$3.33

$2.02

$5.36

1.8%

France

$3.24

$1.31

$4.56

-0.6%

United Kingdom

$2.07

$2.19

$4.27

3.9%

14 DECEMBER 2011 water

Combined water/ wastewater tariff

% increase over 2010

Aarhus (Denmark)

$10.02/m3

11.5%

Nassau (Bahamas)

$8.56/m3

Copenhagen (Denmark)

$7.65/m3

1.1%

Gent (Belgium)

$7.54/m3

9.9%

Bremen (Germany)

$6.93/m3

-4.4%

Berlin (Germany)

$6.90/m3

2.8%

Sydney

$6.62/m3

5.7%

Hamburg (Germany)

$6.56/m3

15.0%

Brisbane

$6.46/m3

6.9%

$6.43/m3

0.1%

City

Glasgow (UK)

Other Australian cities Adelaide

$5.69

27.0%

Melbourne

$6.12

12.8%

Perth

$4.01

5.2%

Sydney, the most expensive Australian city included in the Tariff Survey, fell from fifth spot last year to seventh in 2011 ($US6.62/kilolitre). Brisbane came in at ninth position at $6.46/ kl. In 2011 the most expensive city included in the Survey was Aarhus (Denmark) at $10.02/kl. The cheapest cities included Dublin, Cork, Belfast and Ashgabat (Turkmenistan), all of which provide free water and wastewater services to residents. The most expensive cities surveyed appear in Table 2.

AAA Award Winners Diverse infrastructure delivery teams won national recognition for overcoming adversity and delivering value at the 2011 Alliancing Association of Australasia’s Excellence Awards held in Brisbane in October. Winners include rail, dam-strengthening and busway projects, a long-term wastewater-upgrade program and a senior alliancing practitioner who was recognised for pioneering collaborative practices in the region. Alliancing Association of Australasia (AAA) Managing Director, Alain Mignot, said that while the winners were all very different, ranging across various Australian states and diverse industry sectors, they all demonstrated how good value and public benefit can be achieved despite tight budgets and economic uncertainty. Queensland Rail’s Horizon Alliance won the Team of Excellence in a Project Alliance for its value for money approach to delivering the state’s first multimodal (rail and road) corridor project early and under budget, undeterred by numerous challenges including scope and political change. Melbourne Water Pipelines Alliance won the Team of Excellence in a Long Term Alliance for saving time and cost on a program of brownfield projects. Various innovations were developed collaboratively, with all completed projects achieving actual costs under business case estimates. Sydney Water’s Allan Henderson won the Outstanding Contribution to Industry – Relationship Contracting, acknowledging his long-term contribution to the industry and generous sharing of early experiences in alliancing, including his leadership on Australasia’s first alliance (1997–2001), the Northside Storage Tunnel.

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industry news NWC Annual Report Released

Melbourne Water Pipelines Alliance with their award. Two projects won Highly Commended awards for the Team of Excellence in a Project Alliance, based on their outstanding accomplishments on difficult projects with diverse complexities. New South Wales’ Bridge to Bay Alliance on one of Sydney’s busiest roads, Victoria Road, in densely populated suburbs, achieved numerous firsts to deliver the Inner West Busway project on budget and ahead of time. Mr Mignot said the dedicated bus lane was completed 12 months earlier than was possible via any other form of delivery. Innovative techniques included mobile noise curtains to reduce the impact of night works on neighbours. Western Australia’s Wellington Dam Alliance, initiated to upgrade aging but critical infrastructure, developed a solution that was significantly less than the lowest constructonly price received through an initial competitive non-alliance tendering process. Now in its fifth year, the AAA Award Program celebrates outstanding teams that have exemplified the spirit of collaboration in critical infrastructure projects and programs in Australia and New Zealand. More information and registration details are available at: www.alliancingassociation.org/

The National Water Commission (NWC) has released its 2010–11 Annual Report. Acting CEO Ms Kerry Olsson said, “This report outlines the Commission’s contribution to advancing water reform through its public assessments and transparency reports, thought leadership activities, and investments in practical tools to inform decision making and improve water management. The most important Commission undertaking this year was the preparation of our comprehensive assessment of the progress of water reform in Australia under the National Water Initiative.” A feature essay in the report highlights findings and recommendations to the Council of Australian Governments (COAG), which was publicly released in September 2011. The report also outlines the delivery of other important assessment reports, notably the Commission’s second assessment of the reform actions committed to by the Murray–Darling Basin states under the Water Management Partnership Agreements. The report demonstrates how the Commission’s transparency reports have continued to deliver reliable data benchmarking the performance of water utilities, more accessible water market information and reporting on environmental water management. In addition to providing credible evidence-based advice through its COAG-mandated assessments, the Commission initiated analyses to highlight areas of emerging concern or pressing priority. In 2011, the Commission published a series of reports that chart future directions for the urban water sector and recommend a more coherent approach to reform in urban water, and detail

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industry news specific reform opportunities in pricing, competition, service delivery and water quality regulation. Other contributions to the water reform debate during 2010–11 included position statements on pressing water issues and 22 Waterlines reports that have filled knowledge gaps and improved water management practices. The executive overview to the annual report notes that the Commission’s ongoing role and functions will be reviewed by the end of 2011, stating that it “looks forward to the review, both of our reform work to date and of the future opportunities for an independent, expert water agency to drive the national water actions that are essential for Australia’s future wellbeing.”

Gippsland Water Wins Awards Gippsland Water has won three 2011 Banksia Environmental Awards, including the prestigious overall Origin Gold Banksia Award for the Gippsland Water Factory Project. The Gippsland Water Factory also won in the Water category, and its Vortex Centre and associated ‘Water Wonders’ education program won in the Education category. CH2M HILL was a member of the alliance, along with Gippsland Water, Transfield Services and Parsons Brinkerhoff, which provided project management, design, construction and operations services of the Gippsland Water Factory. CH2M HILL, New Media Magic, LLC, Pico Chicago and Melbourne, and DesignInc were the collaborating partners with Gippsland Water for the creative design and delivery of the visitor experience at the Vortex. The Banksia Awards were presented in Sydney in October. The Gippsland Water Factory is an innovative wastewater treatment and recycling system in the Gippsland region of Victoria.

It uses state-of-the-art technology, including biological treatment, membrane filtration and reverse osmosis, to treat nearly 9.3 mgd (35 ML/d) of domestic and industrial wastewater. The Gippsland Water Factory produces 2 to 3 mgd (8 to 12 ML/d) of high-quality recycled water for use by local industry. Green engineering principles and design were incorporated throughout the project, including co-generation of energy from the biogas generated by anaerobic treatment (330 kW) and a MicroHydro station (340 kW) that captures energy from a large, clean water stream that feeds into the clean water reservoir. The electricity powers operations and minimises environmental impacts.

Australian-ﬁrst Indigenous Project An Australian-first project to improve the liveability of Aboriginal communities is underway in the remote town of Warburton in Western Australia, led by consultancy AECOM, the University of Western Australia and the Shire Council of Ngaanyatjarraku. The Sustainable Warburton Project is a research, design and planning project to create new and improved urban spaces with the aim of transforming how Indigenous people live, that could be applied to Indigenous communities across Australia and around the world. It brings Aboriginal residents of the town, 920km

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DECEMBER 2011 17

industry news PIPE JOINING SOLUTIONS

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north-east of Kalgoorlie, together with a team of AECOM specialists in urban design, ecology, landscape architecture and architecture, and academics and students from the University of Western Australia (UWA). Projects designed include an award-winning community college and an urban agriculture scheme where orange trees irrigated with treated wastewater are planted throughout the town to provide shade, food, protection from dust and improved health. Masters and honours students are now finalising design projects as part of their academic requirements, which will become the basis for funding application and development. Designs will be presented to the Shire Council in February 2012, when the winner of an AECOM prize for the most outstanding design will also be announced.

Concern for Water Reform Progress In its second annual report on Water Management Partnerships, the COAG Reform Council found that progress on water-saving investment projects in the Basin has been too slow. Under the scheme, governments agreed to develop 17 priority projects for approval by the Commonwealth. Thirteen of the projects are led by the Basin States and four by the Commonwealth.

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“We are concerned that after two-and-a-half years only one of the 13 Basin state-led projects has been completed,” Chairman Paul McClintock said. “And at the end of 2010 only one Commonwealth-led priority project was complete.” On water planning and management milestones for 2010 the council was pleased to see that Basin states met the majority of their milestones, while the Commonwealth met all of its milestones. However, Mr McClintock noted that relatively few water planning and management milestones were due in 2010 compared to other years, and many of those milestones related to internal processes rather than major elements of reform. And despite this being such a significant year for the development of the Basin Plan, there were no Commonwealth Basin Plan milestones due in 2010. “We have identified a risk to the Commonwealth meeting its 2011 and 2012 Basin Plan milestones, but unfortunately we could not make a formal assessment of the Commonwealth’s progress,” Mr McClintock said. The council highlighted the risk that timeframes for delivering the Plan will be further extended and this could affect the Commonwealth’s ability to deliver the proposed plan in 2012, as well as the Basin states’ ability to meet a range of associated water planning milestones. To download the full report please visit: www.coagreformcouncil.gov.au

AECOM Appoints New Director AECOM has appointed a flood mitigation specialist to the role of Technical Director of Water Resources in Australia and New Zealand. Joe Chapman has relocated to Brisbane from the US to develop floodplain management and surface-water modelling for AECOM’s Australia and New Zealand water business. Mr Chapman has 23 years’ experience in water resources, including extensive experience in flood risk assessment, flood

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industry news damage reduction measures and disaster management in crisis and recovery situations for the Federal Emergency Management Agency (FEMA) in the US. He also supported the development and implementation of policies and procedures for the National Flood Insurance Program through FEMA. In his previous role, Mr Chapman Joe Chapman led the Watershed Concepts division of AECOM’s water business in North America and was responsible for 13 offices and 160 team members performing floodplain mapping, flood risk assessment, hazard mitigation and geospatial projects for FEMA, as well as state and local government authorities. His new role will also involve establishing procedures and systems to enhance work sharing across AECOM’s businesses in Australia and New Zealand, and around the world.

Community Support for Perth’s Groundwater Replenishment Trial The Water Corporation’s Groundwater Replenishment Trial, which involves further treating secondary treated wastewater to drinking water standards and recharging it to groundwater, is well underway. Community engagement and support are integral to its success and are a key focus for the project team. Community attitudes have been monitored since 2007 to determine concerns and levels of support for groundwater

20 DECEMBER 2011 water

replenishment from both an informed and uninformed position. This data is collected through a variety of means including phone surveys, focus groups, surveys collected at community events and tours. Phone survey results from 2011 indicate 67 per cent support for recycled water becoming part of Perth’s drinking water supply, with 21 per cent of respondents in opposition and 12 per cent unsure. These results have remained fairly consistent since surveying began. Along with other engagement initiatives, the Advanced Water Recycling Plant and custom-built Visitor Centre in Craigie continue to play a key role in engaging with the Perth community. Tours of the facility began shortly after the trial’s launch in November 2010, with an excellent response from community, industry, stakeholders and school groups. So far nearly 4,000 people have toured the facility. Community feedback from tours indicates that outright opposition is low and people are generally supportive of groundwater replenishment. The research conducted through the tours and at other community events shows that generally support for groundwater replenishment increases once people have more information about the treatment process and learn about examples of recycled water schemes successfully implemented around the world. Educating schoolchildren about the water cycle, water recycling and

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industry news

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DECEMBER 2011 21

industry news guidelines retain currency with the latest scientific evidence. The latest version was released in late October 2011 at the South-East Queensland Water Grid Emergency Management Room. Development and maintenance of the ADWG content was jointly funded and endorsed by NHMRC and the Natural Resource Management Ministerial Council (NRMMC*). In conjunction with the ADWG, NHMRC and the National Water Commission (NWC) released the upgraded Community Water Planner (CWP), designed to assist operators of small water supplies in rural and remote areas to implement the ADWG.

A school tour at the centre. groundwater replenishment is recognised as an integral part of both the trial’s community engagement program and the Water Corporation’s ongoing commitment to water education. Free tours of the Advanced Water Recycling Plant have been offered to metropolitan school students in Years 5–12, supported by a Corporation initiative to cover transport costs for 50 schools during the second half of 2011. School tours are now fully booked until the end of 2011.

Review of Australian Drinking Water Guidelines and Community Water Planner Australia’s recognition of the significance of providing safe drinking water, good sanitation and hygiene has improved the health and life expectancy of Australians. However, producing safe drinking water is an ongoing challenge that can never be taken for granted by those responsible for producing and regulating drinking water supplies. The National Health and Medical Research Council (NHMRC) has provided guidance in this field for over 40 years and the Australian Drinking Water Guidelines (ADWG) are recognised as the authoritative Australian reference on drinking water supplies. The ADWG are used by agencies associated with the supply of drinking water, including catchment and water resource managers, drinking water suppliers, water regulators and health authorities. They form the basis of State and Territory legislation, Memorandums of Understanding and Codes of Practice. The ADWG are reviewed on a rolling basis by NHMRC, which is reflective of the importance NHMRC places on ensuring the

The 2011 ADWG edition has retained the major structural change and focus of the 2004 edition. The change was undertaken to enable assurance of drinking water quality before supply and was achieved via the addition of a comprehensive risk management approach (the Framework for Management of Drinking Water Quality – the ‘Framework’). Previously the quality of drinking water was determined based on water test results, which were inevitably not available until after the water had been consumed and were, therefore, too late to prevent illness. The Framework was introduced in 2004 after several reminders that when things go wrong the consequences can be severe. In 1993 a single outbreak of Cryptosporidiosis in the US1 caused over 400,000 illnesses, while in 2000, seven people died and over 2000 people became ill following E. coli contamination of a small water supply in Canada2. Australia was reminded of the sensitivity of water supplies in 1998 when residents of Sydney were advised to boil their drinking water for several weeks as a result of detection of Cryptosporidium and Giardia in Warragamba Dam. The Framework has been particularly successful and has been applied to water supplies ranging from rainwater tanks to major capital cities. It is a practical flexible approach that significantly improves the quality assurance of drinking water supplies. Changes to the ADWG: The latest review of the ADWG began in 2007 and was completed in 2010. The review priorities were determined following consultation with stakeholder groups, with the revision process overseen by the NHMRC Water Quality Advisory Committee (WQAC). Five key areas were reviewed, resulting in the following changes: • The addition of over 120 new Fact Sheets, and 30 updated Fact Sheets on micro-organisms, blue-green algal toxins, inorganic and organic chemicals including emerging parameters such as the disinfection by-product NDMA (N-Nitrosodimethylamine). Most of the Fact Sheets deal with health parameters, but some deal with acceptability issues such as taste and odour and total dissolved solids or salinity;

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industry news • New guidance on performance requirements for filtration plants; • A complete revision of the Chapters on all aspects of monitoring, assessment of results and appropriate responses where necessary; and • New guidance on pharmaceuticals and endocrine disrupting compounds that have received much attention in recent years. The ADWG can be accessed at: www.nhmrc.gov.au/ guidelines/publications/eh52. The Community Water Planner Tool: The revised CWP tool replaces the 2006 CD-based version, which predominantly addressed microbial issues, acknowledged as posing the greatest health risk in Australia. The new webbased tool, expanded by NWC to cover physical, chemical and radiological risks, is designed for use by people with some knowledge of the design and operation of drinking water supplies and is for use by experienced community water supply operators or service providers. The tool enables uptake of the ADWG Framework by generating water safety plans based on user input. Adherence to the water safety plans will help to ensure safe drinking water supplies in remote communities, including Indigenous communities, where water quality sometimes falls short of meeting ADWG levels. The tool can assist in closing the gap on Indigenous disadvantage by improving the quality of drinking water supplies and, therefore, the health of those living in remote locations. The CWP can be accessed at: www.nhmrc.gov.au/guidelines/ publications/eh52web.

From left to right: Murray Radcliffe, NWC; David Cunliffe, Chair NHMRC WQAC; Barry Dennien, South East Queensland Water; and Don Bursill, former Chair, NHMRC WQAC. *As of 30 June 2011, NRMMC ceased to exist and its functions have been taken over by the Standing Council on Environment and Water (SCEW).

References 1. Davis JP, MacKenzie WD, Addiss DG, 2009: Lessons from the Massive Waterborne Outbreak Of Cryptosporidium Infections, Milwaukee, 1993. Global Issues in Water, Sanitation, and Health: Workshop Summary. Institute of Medicine (US) Forum on Microbial Threats. Washington (DC): National Academies Press (US). 2. Hrudey SE, Hrudey EJ, 2009: Prevention is Painfully Easy in Hindsight: Fatal E. Coli 0.157 and Campylobacter Outbreak in Walkerton, Canada, 2000. Global Issues in Water, Sanitation, and Health: Workshop Summary. Institute of Medicine (US) Forum on Microbial Threats. Washington (DC): National Academies Press (US).

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DECEMBER 2011 23

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awa news Young Water Professionals (YWP)

Amanda Hazell – AWA YWP National Committee President During National Water Week I was fortunate enough to be able to go and visit a local scout group in my area as a National Water Week Ambassador. The scouts, aged seven to 10, were busy working towards their waterwise badges and we completed a number of water awareness activities as part of this. The group was extremely enthusiastic and knew a great deal about water conservation, especially the scouts who lived in homes where their water supply was dependent on rainwater tanks. As a water industry member I was extremely confident to leave them, knowing that making the most of this precious resource was on the forefront of their minds. Sadly, this will be my last article as YWP Chair. At the time of writing, a new YWP Chair had not yet been appointed, but the process is well underway. However, since the last time I wrote we have two new national representatives: Trevor Lynn from Western Australia and Tim Beckenham from Queensland. I hope that Trevor and Tim enjoy their time on the committee as much as I have in the last four-and-a-half years. It is great to be able to reflect on my time in the YWP National Representative Committee; I have had the opportunity to experience so many areas of the water industry. One important thing I have learned is that it’s the people working in the water industry who make it what it is. On attending major water industry events I’ve been amazed to discover that many of the people I talk to have been in the industry for 25 years or more. What makes these people even more impressive is that

not only do they have the technical knowledge to get the critical jobs done – they also have a huge passion for the industry. As adaptations have been needed they have had the courage and the foresight to implement the more innovative options and put them on the table. As someone who works in a water utility, the water industry for me is a very different place than it was a few years ago. When I started my term as YWP President, most of the capital cities were working as quickly as possible to get desalination plants, recycling plants and pipelines built so that they didn’t run out of water, and much of rural Australia was also in drought. Fast-forward two years and now much of the east coast has so much water that water restrictions are being scaled back, pipelines have hardly been used and utilities are working out what to do with their desalination plants when they are not needed. Along the way there has been a lot of criticism about why things were built and why certain decisions were made. Happily, as an industry we have been able to pull together and realise that these decisions were made by industry leaders whose goal was to ensure that their customers still had access to one of our most basics services. As someone new to the water industry (and yes, I do still count myself as new – five years is not very long compared to 30!), it is these people that I am proud to look up to. They and our customers, the Australian community, inspire me to continue to learn as much about our industry as possible. Hopefully, all of us who are new to the water sector will do the same thing, so that when it comes to our turn to make crucial decisions we have the same courage. We need to make sure that the people in our industry stay as strong as they have always been.

National Water Week Ambassador Peter Devellerez helps educate kids become more water-aware at the Herne Hill Scouts Club (WA) during last year’s NWW.

26 DECEMBER 2011 water

I would like to say thank you to all the wonderful people who have supported me during my two-year term as President – all the YWP committee members, both on the National Representatives Committee and the state committees. It is your hard work that keeps our YWP members engaged. Thanks also to the AWA board members who were always there to offer advice and guidance, and my managers at the Water Corporation and Degrémont at Perth Seawater Desalination Plant who supported me in this role. Finally, I’d like to thank the AWA staff members who support the YWP and all the other specialist networks; if it wasn’t for them these networks just would not run. Special thanks to Kim Wuyts who has been our YWP AWA contact for over a year now and always does a fantastic job. The experience has truly been a rewarding one for me.

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awa news Does Science Really Matter? AWA’s Environmental Water Management Specialist Network hosted a workshop at the 14th International Riversymposium, held at the Brisbane Convention and Exhibition Centre in September (see page 54 for a review of Riversymposium). The theme of the session was the deliberately provocative: ‘Does Science Really Matter in Environmental Water Management?’, which aimed to explore the challenge of integrating science and research in on-the-ground decision-making in environmental water management.

Fiona (far left) with colleagues from the Pacific Water Association.

A Samoan Experience Earlier this year Fiona MacKenzie, Project Manager – Skills, AWA was selected as a recipient for the Endeavour Executive Award, an Australian Government merit-based scholarship program that provides opportunities for Australians to undertake study, research and professional development abroad. Fiona was thrilled to take up a placement based in Apia, Samoa, with the Pacific Water Association (PWWA) from June–September 2011. The PWWA is a regional not-for-profit membership body established in 1995 to support the Pacific region in meeting water challenges. Pacific island utilities are the primary member group serviced by a voluntary Secretariat in Apia. The Association plays a vital and unique role for the Pacific water sector; however, due to lack of funds and resources it is in a precarious position. PWWA and Fiona identified a list of projects that would improve the Association’s capacity and membership services. Activities during her placement included the development of a contact database, website content and an annual report, streamlining processes and also coordinating, facilitating and presenting at the PWWA Pacific Water Conference. However, the two biggest accomplishments were the Memorandum of Understanding (MoU) between AWA and PWWA and the PWWA Review and Recommendation Report. Peter Robinson, AWA’s immediate Past President, signed the Agreement at the Pacific Water Conference in September, which formalised the relationship between the two Associations. The MoU aims to foster communication and collaboration by sharing news, training and event opportunities, forging business relations and twinning partnerships between members, and the provision of crisis support between Australia and Oceania. The most influential initiative for PWWA was a Recommendations Report, which provided an analysis of financial and membership figures and Association documents and processes, and concluded with an Action Plan. The Executive Board commended and approved all the growth-focused suggestions and the Secretariat will implement these changes immediately. This will have a positive and ongoing impact on the Association. Fiona found the opportunity to work with the Pacific water community an enlightening, humbling and rewarding experience. The circumstances and challenges of water in the Pacific – such as Tuvalu’s water shortage crisis and the impact of sea level rises on the disappearing Kiribati islands – are both broad and critical. During her time in Samoa, Fiona developed good working relationships with the Secretariat and the Pacific island utilities and also enjoyed the “fa’a Samoa”, which means the ‘Samoan way of life’.

28 DECEMBER 2011 water

Panelists representing scientists, managers and community members provided brief stimulus presentations offering case studies of successful (and perhaps not so successful) dialogues between science and decision-making in environmental water management. The panel included: • Paula D’Santos – Senior Wetlands & Rivers Conservation Officer, NSW Office of Environment and Heritage (OEH); • Paul Harding – Consulting Hydrologist, Qld Dept of Environment and Resource Management (DERM); • Judy Frankenburg – a farmer at Howlong, near Albury, NSW, and Plant Ecologist; and • Dr Joanne Ling – Rivers and Wetlands Unit Co-ordinator, NSW Office of Environment & Heritage. The session attracted around 50 delegates and the presentations sparked some passionate and interesting discussions. The session was ably chaired by Greg Raisin, MDBA (formerly with NWC), and the debate stirred with the help of facilitator Dr Deb Nias, CEO of Murray Darling Wetlands. The key points that came out of the session included: • The best-laid plans can, and will, be undone by legislation. The rules are not always enabling and there is a need for flexibility in policy. • Communication and management of expectations are essential. The tools and products developed by scientists need to be developed with clear understanding of the manager or community expectations; co-development is important. • There needs to be more emphasis on the importance of preinvestigations before acting. Observation and early enquiries can improve the situation and lead to greater outcomes. • Lack of monitoring, or of any data in some places, makes justifying decisions difficult to community, policy and even self. • The pressure to be efficient with water use can work against what the science is telling us. For example, the need for overbank flows for ecosystem function is not compatible with efficiency measures. • The role of uncertainty and the need to explain this. Look to trends rather than absolute numbers. We must encourage learning by doing, and be allowed to make mistakes. Adaptive management principles must be applied. • The need to understand more than the biology or hydrology. Social, psychological, economic and political sciences are perhaps more important in some decision making. The science is broader than the biological-based sciences. • The science behind the basin plan needs explaining to the managers too. How can managers support the plan when they don’t understand how the data was derived and why there are different volumes?

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awa news • Environmental allocations are treated the same as consumption or irrigation, but they are fundamentally different and should be treated differently. These differences need to be explored in each region and any means to improve flexibility identified. • What science should we be doing now to answer the questions of the future? What are the questions managers really need answered? Are they different to what some scientists think they are? How do we change this? • We may need to re-educate ourselves in terms of understanding people and their motivations. There is a need to speak plainly in ways others can understand. The session participants were also asked how the Environmental Water Management Specialist Network might help deal with some of these issues. Suggestions included: • Advocate for legislation flexibility and make a case for why environmental allocations should be regarded differently to consumptive licenses; • Be a forum for mentoring and information; • Find a forum to bring Basin Plan scientists together with managers to show how the data was derived, and discuss; • Find training courses in communication (e.g. media training) where complex issues can be synthesised and explained. The Environmental Water Management Specialist Network committee will consider these points when deciding on activities to be included in their Action Plan. For more information on the workshop or any aspect of this network’s activities, please contact Laura Evanson on (02) 9467 8433 or email: levanson@awa.asn.au

ANZBP Workshops The Advisory Board of the Australian & New Zealand Biosolids Partnership (ANZBP) held a meeting in Canberra in October. The event saw the group farewelling longstanding members Dr Mike Mclaughlin (CSIRO) and Mike Makestas (SA Water). As foundation committee members, their contribution during the establishment of the ANZBP and their ongoing support and advice is greatly appreciated. The meeting welcomed incoming representatives Dr Bill Barber (AECOM) and Dr Rai Kookana (CSIRO), each of whom has extensive experience both locally and internationally in a variety of biosolids managements fields. The event was well attended, with the group being privileged to hear from new Board member Bill Barber. Bill’s background in the UK water sector provided some fascinating contrasts to Australian experiences and his knowledge of wastewater management and climate change impacts made for topical discussion. Tung Nguyen of Sydney Water presented the biosolids management strategy for Sydney and the surrounding area, providing the group with insight to the multi-layered issues that need to be addressed in such a strategy and the detail in managing risk effectively.

on efficient management of lagoons and presented potential alternative biosolids management methods for the future. Led by Board Member Paul Darvodelsky, the relaxed event generated much discussion and provided attendees the opportunity to hear from each other and learn about each other’s activities. Plans are being made to hold 2012 workshops in Geelong, the Gold Coast and Wellington (NZ). If you would like to engage your stakeholders in a discussion on biosolids management, consider the opportunity to host a workshop in your location. Please contact the Project Manager (details below). The ANZBP is a subscription based program formed in 2007 by the Australian water sector to place the beneﬁcial use of biosolids on a sustainable footing across Australia and New Zealand. The ANZBP resides within AWA, which implements the program and its associated activities. Membership enquiries are welcome and can be directed to Gregory Priest at AWA’s National Ofﬁce: gpriest@awa.asn.au or (02) 9467 8432.

Online Document Library and RSS Feed Launched AWA has launched its much-awaited online document library. The library is designed to contain technical articles from Water Journal, conference reports and other documents of interest. Documents will be regularly added as the library continues to grow into a valuable and accessible information resource. Access to the AWA online library, which is located under the Publications tag on the AWA website (www.awa.asn.au) is a membership benefit, meaning it is free to AWA members; non-members can submit requests for copies of specific documents for a small fee. To keep you abreast of all the latest industry news, you can also sign up to the AWA RSS feed. News from the water sector and related industries is gathered every morning from the most reliable media resources and sent to your inbox or live bookmarks. Simply sign up from AWA’s homepage at: www.awa.asn.au and never miss an important news item again.

Tasmania Branch News AWA Tasmania 2011 Galah Debate The 2011 Galah Debate was held on 22 September at Wrest Point in Hobart. Guests took time to enjoy the food, company and collegiality this annual event brings. The event is now firmly entrenched in the Tasmanian calendar and is looked forward to by corporate partners, guests and the debate teams. The Southern Debate Team, captained by Aniela Grun with debaters Phil Gee, Lance Stapleton and Elspeth Moroni, worked hard to retain the trophy but the Northern Team, led by vicecaptain Ed Gruber, won the day. Seasoned debater Ray Wright, supported by James McKee and Chris Thompson, won over the audience with their compelling arguments and innovative props.

The group also heard from local Chris Hepplewhite, who described the biosolids management process for Canberra, explaining how thermal destruction (incineration and soil application of ash product) is, despite general perception, the most appropriate method for ACTEW Corporation to treat and reuse biosolids. An ANZBP workshop in Darwin in November was similarly well attended, with Power and Water Corporation employees from both Darwin and regional areas making up the majority of attendees. With the Northern Territory predominantly relying on lagoon systems to treat and manage biosolids, the session focused

30 DECEMBER 2011 water

The winning team (at left) display their award.

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awa news Mr Barry Dennien, CEO of the South-East Queensland Water Grid Manager, was this year’s special guest speaker. Barry’s perspective on the destruction and recovery that ensued after the recent Queensland floods was appreciated by the attendees.

Queensland Branch News Qwater’11 Regional Conference More than 160 AWA members gathered at Novotel Twin Waters on the Sunshine Coast on 4–5 November to explore the challenges, solutions and opportunities for future water supplies and sewerage services in South-East Queensland. The regional conference brought together participants from all aspects of the industry to share their knowledge and experience in capturing, managing and treating water and sewage. A trade exhibition also showcased many new and innovative products. Unitywater CEO, Jon Black, said it was essential for the water industry to work together to ensure SouthEast Queensland’s ongoing water security in the face of continued population growth, and the organisation was proud to be

Delegates and their families were treated to a night at the circus. hosting the event. The conference also considered the role of the water industry in delivering affordable housing for a growing population; emergency management; and whether the current management model in South-East Queensland is the most effective way to meet the region’s needs. Well-known as a family-friendly conference, delegates and their family were treated to a night at the circus. Over 250 people attended an evening of spectacular entertainment, which included two delegates becoming stars of the show. Natalie Muir (Cardno) and Selwyn McFaul (McFaul & Co Engineers) took to the high trapeze, much to the delight of young and old. The conference culminated with a dinner on Saturday night, with delegates taking to the dance floor after being entertained by comedian Fiona McGary.

All set up for the Saturday night dinner.

Our thanks to our sponsors: Unitywater; KBR; Tyco Water; Acciona Agua; MWH; ITT Water & Wastewater; UGL Limited; and Wise Waste Solutions.

Call for Papers closes soon 9 th IWA Leading-Edge Conference on Water and Wastewater Technologies

Supporting publication:

3–7 June 2012 Brisbane Convention and Exhibition Centre Brisbane, Australia 32 DECEMBER 2011 water www.let2012.org

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

NEW CORPORATE MEMBERS ACT Corporate Gold waterAUSTRALIA Corporate Bronze Gunnedah Shire Council ZSNY Water Australia

QLD Corporate Bronze Griffith School of Engineering JTA Australia

SA Corporate Bronze Adelaide Pipeline Maintenance Services

VIC Corporate Silver Aerzen Australia Green Process Corporate Bronze Airepure Australia Pty Ltd Griffith Hack

WA Corporate Bronze Corrs Chambers Westgarth

NEW INDIVIDUAL MEMBERS ACT M. Maliel, W. Johnson, C. McLennan, S. Rashid NSW A. Thakur, A. Peel, D. Stoker, C. Lingard, D. Wolfenden, D. Barnetson, I. Evanson, J. Mann, J. Maniord, K. Sheridan, L. Targ, L. Kelly, N. Esber, P. Collins, M. Ridger, P. De Santis, N. Lewis, P. Phillips, R. Gatley, M. Smiley, W. Liu, D. Szczepanski, P. Harley, N. Biltris, R. Wakefield, A. Mansfield, B. Harper, J. Brown, M. Mickaeal, R. Longmire, S. McKay NT J. Luchich, J. Phasey, V. Bhaskar QLD A. Chapman, B. Jones, C. Staib, B. Everitt, D. Dickson, E. McKone, G. Smart, G. Grieve, G. Haywood, G. Stevens, I. Maynard, S. Bessell, R. Evans, M. Flounders Bowman, S. Hausler, T. Belgrove, T. Collins, P. Flint, P. Fraser, S. Moore, B. May, A. Coe, J. Timones, S. Spencer, T. Wohlsen SA A. Marling, A. Miller, D. Tessari, D. Eilers, D. Dally, J. Bailly, K. McAlpine, K. Ross, S. Forsyth, A. Roberts, M. White, P. Dalby, K. Cox, P. Doumouras TAS A. McConachy, R. Beaumont VIC A. McIntosh, A. Heckenberg, B. Smith, B. Barham, B. Van Heer, D. O’Donovan, D. Perry, D. Ellwood, E. Hannan, D. Peterson, G. Holland, I. Rutherfurd, J. Wardle, I. Gray, E. Henty, J. Anderson, J. Pannach, J. Day, K. Tofari, M. Pickles, M. Miller, M. Hyatt, M. Briggs, M. Wheaton, M. Potter, N. Ozbey, P. Dowland, R. Oliver, T. Noble, R. Chambers, P. Giagoudakis, R. van Kuyk, O. Shahin, M. Green, T. Lloyd, M. Rogers, N. Carracher, T. Lohman, T. Routley, N. Gartner, V. Hadzihalilovic, R. Neale, S. Spencer, R. Heale, S. Gobrial, T. Grogan, E. Sullivan, D. Rose, J. McCallum, M. Sheffield, R. Bikins, T. Wright, C. Willis, D. Mainville, D. Comrie, F. Blin, M. Kreutzer, M. Steele, M. Welk, S. Tucker, S. Richardson

WA A. Churley, C. Ferrari, C. Doran, C. Dawkins, D. McDonald, F. Crowe, J. Stapleton, J. Harris, L. DeMello, M. Tonkin, S. Johnson, S. Urquhart, R. Fourie, M. Pugh, G. Field, L. Chalmers, M. Vanderwey, S. Kuebler, E. Semisi Overseas A. Rochstad, B. Chua, C. Elisha, C. Tze Kiong, H. Joo Meng, Y. Chua, M. Than Htaik Aye, W. Chang, S. Yuan Kang, S. Wei Yan Angie, T. Leem Tien

NEW STUDENT MEMBERS NSW A. Abujubbeh, J. Stanley, L. Bolton, P. Masi QLD C. Smeal, E. Park, T. Leslie SA D. West

YOUNG WATER PROFESSIONALS ACT G. Sturesteps, T. McNaught NSW A. Wilson, K. Jones, N. Vemuri NT A. O’Neill, A. Wacker, N. Smith SA R. Edwards TAS S. Kruimink VIC A. Rodriguez Velarde, D. Hyne, D. Young, D. Kiernan, E. Rudd, J. Katalinich, J. Sims, S. Trimmer, N. Suprapto, S. Campbell, M. Debnam, S. Pascoe WA B. Rakowska, P. Arthur

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

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 December

Thu, 08 Dec 2011

SA Technical Meeting, Adelaide, SA

Fri, 09 Dec 2011

QLD Branch Christmas Party, Brisbane, QLD

February

Tue, 28 Feb 2012

Technical Seminar, Hobart, TAS

March

Sun, 25 Mar 2012 – Tue, 27 Mar 2012

IWA Water Security Conference – Resilience 2012, Sydney, NSW

Wed, 28 Mar 2012

Stormwater Seminar, Launceston, TAS

April

Tue, 24 Apr 2012

Technical Seminar, Hobart, TAS

May

Tue, 08 May 2012 – Thu, 10 May 2012

Ozwater’12, Sydney, NSW

Tue, 22 May 2012

Technical Seminar, Hobart, TAS

Sun, 03 Jun 2012 – Thu, 07 Jun 2012

IWA Leading Edge Technology, Brisbane, QLD

Mon, 18 Jun 2012 – Wed, 20 Jun 2012

AWA Biosolids and Source Management National Conference, Gold Coast, QLD

Tue, 26 Jun 2012

Technical Seminar, Hobart, TAS

Wed, 25 Jul 2012

Technical Seminar, Hobart, TAS

Fri, 27 Jul 2012

Technical Seminar, Launceston, TAS

August

Wed, 15 Aug 2012

TASWATER12, Hobart, TAS

September

Tue, 25 Sep 2012

Technical Seminar, Launceston, TAS

October

Thu, 25 Oct 2012

Technical Seminar, Launceston, TAS

November

Thu, 22 Nov 2012

Galah Debate, Hobart, TAS

June

July

34 DECEMBER 2011 water

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feature article

Assessing Australian Water Reform Chloe Munro is the Chair of the National Water Commission. This is an edited extract of her speech to launch the Commission’s 2011 assessment of Australian water reform. The National Water Commission’s third biennial assessment of the implementation of the National Water Initiative has special significance. It is not just an assessment of progress by governments in implementing the actions to which they committed when signing the initiative. It is also an assessment of the extent to Chloe Munro, which these actions have improved the Chair, National sustainable management of Australia’s Water Commission water resources. In other words, it is an assessment of the impact of the initiative itself. The Commission’s conclusion is that water reform under the guidance of the National Water Initiative has been worthwhile. The report demonstrates tangible benefits from the progress that has been made. The going has been hard in places and not everything has been achieved that was anticipated when the initiative was agreed in 2004. Water management is complex and so water reform is complex. Water management is challenging and so water reform is challenging.

The Right Framework When the National Water Initiative was signed, Australia had for the first time a nationally agreed, coherent set of principles and reform actions for water with the aim of achieving economic, social and environmental outcomes. Through its assessment, the Commission found that the National Water Initiative remains robust and relevant. It is robust in the core principles that it articulates about the inter-related elements of good water management. It is relevant in that it continues to enjoy broad and sustained stakeholder support. It has been a focal point for water reform nationally, providing clear direction for governments and for water users. And where its commitments have been met, stronger, more transparent and more accountable institutional arrangements have been put in place. The National Water Initiative is recognised globally as a model for good water governance, for addressing the challenges of cross-jurisdictional management of shared resources, and for harnessing the power of markets and price signals to encourage efficient use and investment.

Taking into account what has been learned so far, the recommendations address gaps, shortcomings and new issues. In summary, the recommendations cover three key elements that are essential to continuing national water reform: renewed leadership, a maturing of the water management agenda, and a focus on the national arrangements that will make it happen.

Positive Progress Firstly, the Commission reports that there is good progress in many areas of water reform. Based on our analysis and on discussions with industry, with government, with experts in the field and with interested individuals, it’s clear that the implementation of National Water Initiative commitments has delivered tangible benefits to individual water users, to communities and to the environment. In rural Australia, water users in most jurisdictions have a more secure and tradeable water asset, and environmental water needs are better recognised in law and in water plans. Water trading has become a vital tool for many irrigators in responding to variable water availability and to other market factors. This has been supported by the removal of many artificial barriers to trade, by the facilitation of interstate trade and by the implementation of better service standards and transaction systems. Water markets have produced positive economic gains at the community, regional and national levels. Surface water, at least in the Murray–Darling Basin, is traded in an increasingly mature market. Market mechanisms have allowed governments to step in and buy water for the environment. This is a cost-effective means to adjust the balance between environmental and agricultural uses of water while respecting the framework of entitlements. Our cities and towns have more certain water supplies because actions taken under the initiative have made water use more efficient and sustainable. Major capital investments have improved the security of water supply in Australia’s urban centres by bringing online additional supply options. Through improved governance, there is now a better understanding of the rules, roles and responsibilities of the people and institutions involved in water management. Significant investment has been made in improving how we account for water, in metering water use, and in the science behind water decision making.

Importantly, the agreement contains an innovative mechanism for maintaining and refreshing the water reform agenda – effectively a series of regular checkups – to be provided to COAG and publicly reported. Our latest report set out what has been achieved in water management and put forward a potential roadmap for building on and reinforcing these achievements. This roadmap is laid out in 12 recommendations – critical actions to reinvigorate Australia’s water reform agenda and ensure that wise stewardship of our water resources remains a national priority.

36 DECEMBER 2011 water

Water trading in rural areas can be an important management tool.

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feature article security of water for rivers and wetlands. In extreme conditions, water plans have been set aside. Accountability for environmental outcomes remains weak, even when they are specified in the plans. In particular, monitoring capacity is often inadequate, and plans still lack the necessary science to link environmental watering with ecological outcomes. Nevertheless, the planning cycle continues and generally new plans are more soundly based than older ones. The real test for how well we are doing to keep a fair share of the resource for the environment will be when drought conditions return.

Environmental water needs are now better recognised. Pricing and institutional reforms have also been beneficial. Consumption-based and cost-reflective pricing has encouraged more efficient water use. The recovery of full efficient costs means that many water businesses are now better placed to fund necessary maintenance and new investment. Independent economic regulation and consumer protection frameworks, where implemented, are improving transparency and accountability while protecting disadvantaged customers.

Disappointments On the other side of the ledger, the report documented some borderline results and even fails. Some of this can be attributed to the complexity and ambitious nature of the reform task. Many of the agreed actions are inherently difficult, and some of the deadlines were unrealistic even when the National Water Initiative was signed. As a result, many important actions are not complete. Drought has distracted and complicated the implementation effort as well as masked some of the results. Political commitment and leadership have been variable, and bureaucratic processes have been slow and often obscure to those to whom the outcome matters most. Historically high levels of investment in water management and infrastructure have not always been well aligned with reform objectives.

The Commission put a marker down in its 2009 biennial assessment and said, ‘water is still in trouble’ because we saw insufficient progress towards the core commitment of the National Water Initiative: the commitment to tackle over-use and over-allocation. Regrettably, we find that this position has not improved. The Commission is deeply disappointed that the stated commitment of parties to make substantial progress by 2010 in adjusting all over-allocated or overused water systems to sustainable levels of extraction has not been met. Some governments remain reluctant even to identify explicitly their over-allocated and over-used systems – surely a necessary first step towards restoring those systems to sustainable levels of extraction. Nowhere is this a challenge more than in the Murray-Darling Basin. The implementation of the Basin Plan will be a critical test for water reform and for Australia’s ability to address the core challenge of managing water sustainably. The Water Act put in place a new governance model for the Basin. But this is not sufficient in itself to resolve the continuing and complex challenge of achieving a management regime that, in the words of both the National Water Initiative and the Water Act, ‘optimises social, economic and environmental outcomes’. The failures of the past to achieve sustainable water management in the Basin have been as much failures of leadership as of the particular legislative and governance structures in place at the time.

Meanwhile, community confidence has been damaged by delays in delivering on commitments, by inconsistent implementation and by less than adequate involvement of affected communities.

Sustainable Water Management Outcomes for the environment from water reform are not as clearly demonstrated as the outcomes for the economy. While we have seen welcome progress across jurisdictions in the development of environmental water management institutions and the recovery of water for environmental needs, we have also seen how easily ad hoc government interventions can undermine the

Security of water for rivers and wetlands must not be undermined.

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feature article Likewise, today, successful reform will depend on real leadership from all Basin governments and active involvement by Basin communities to focus on the long-term public interest. The Commission also observes that progress has been disappointing in the acknowledgement of the cultural values of water resources for Indigenous Australians. Many water plans do not consider Indigenous cultural values and economic development. Even where acknowledged, few steps have been made to develop strategies to address those interests. Our report identifies other key areas that are still to be implemented effectively. These areas include addressing currently unregulated forms of water interception; finishing the job in pricing and economic regulatory reform; continuing to put in place the metering, compliance and enforcement capacity needed to ensure confidence in our licensing systems; and fully implementing the commitments regarding groundwater/surface water connectivity.

Looking Ahead The consistent message relayed to the Commission from stakeholders and government agencies is that the approach spelled out in the National Water Initiative is fundamentally sound. But if we are to deliver in full on the aspiration of the initiative there must be renewed leadership, a maturing of the water management agenda and a focus on the national arrangements to make it all happen. We need the leadership to set goals and visions, to communicate the benefits of reform and to make the difficult trade-offs that are in the long-term public interest but may have short-term costs for some parties. Above all, political leadership is required to maintain resourcing for the building blocks of water management among competing priorities, and to stand firm in the face of political expediency. In particular, urban water reform commitments in the National Water Initiative were limited in scope. This shortcoming became particularly evident as the drought highlighted weaknesses in the arrangements for managing the supply-demand balance in our cities.

government can support each other, but gaps, overlaps and inconsistencies can also lead to inefficient and undesirable results. This is particularly the case where new frontiers are being opened, for example measures to address climate change or the rapid growth of new industries impacting on water resources. The Commission has also advocated greater coordination between water management and natural resource management initiatives, and a greater focus on water quality as an integral part of more effective water management. This will improve environmental outcomes and result in a more coordinated and structured approach to urban water quality regulation. It will be difficult to maintain the momentum of reform without effective mechanisms to make it all happen. The Commission has proposed that governments take a more strategic approach to the reform work program and to the reporting requirements that operate under the auspices of COAG. One of the cornerstones of improved water management is better knowledge, science and information. Despite significant investment and gains in recent years, there is still no national, strategic and coordinated approach to planning and funding science to support water planning and management in the most efficient manner. We say there should be.

No Room for Failure The National Water Initiative has been a powerful and important instrument in improving water management in Australia. The Commissionâ&#x20AC;&#x2122;s view is that, as a consequence, water in Australia is managed better than it was in 2004. But there is still a distance to go. Getting there will require a determination to be in it for the long haul; a willingness from all involved to work cooperatively in the national interest. There is no room for failure. The prospect of increased climate variability, the emergence of new demands on the resource and an inevitable return to drought make sustainable management of Australiaâ&#x20AC;&#x2122;s water an enduring national imperative. This is an imperative that binds us all in the continuing implementation of a national water reform agenda.

Stop-go policies and poorly communicated investment decisions have undermined community confidence. Rising prices have become the issue, while questions of value and service have been obscured. The Commission has, therefore, proposed a coherent urban reform plan based on clear objectives and accountabilities for this increasingly complex and diverse sector. Sustainable water management cannot be achieved in isolation. The high-level objectives of water reform interconnect with many other facets of government, including energy and resources policy, regional development, natural resource management, climate change adaptation and mitigation strategies, and urban planning. On the ground, programs and policies deriving from different areas of

38 DECEMBER 2011 water

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The Right to a Fair Share Phil Duncan is the Chair of the National Water Commission’s recently established First Peoples’ Water Engagement Council. This is an edited extract of his keynote address to the recent 14th International Riversymposium. Over millennia Indigenous Australians have sustainably managed our lands, waters and natural resources for the health of our countries and our peoples. We have understood the importance of water and its centrality to life and have cherished it accordingly. Our traditional ecological knowledge, like our stories, is passed down from generation to generation. This knowledge has allowed us to live in a symbiotic relationship with the land and water. We use it, we live from it, we nurture it. Historically our use was sustainable, and this continues today – where it can. But there is a distinct difference between how we manage and look after our environments and sites, and the way nonAboriginal people see and manage them. For us, right across Australia, there are many cultural signposts that, along with our stories, guide our interaction with the environment. Our trees, ceremonial grounds/Bora rings and rivers mark boundaries for clans and nations. Our trees are carved with our stories – our lore – and mark boundaries as well as secret and sacred areas. Unfortunately, these cultural signposts have not always been respected as they should be. In the past, our rivers were travelling highways for trading between nations and movement through our country. Rivers were places for initiation and birthing – places to connect our peoples and nations through story, song and dance. Our ceremonial grounds, our Bora rings, have always been near the rivers. Sadly, however, many of these have been ploughed into the ground to make way for crops, sheep and cattle grazing, without any thought of, or engagement with, the descendants of the Traditional Owners. The wetlands are our supermarkets and contain significant ceremonial sites for both women’s and men’s business. In the Murray-Darling Basin (MDB) alone, 11 wetlands have been shut down and disconnected from the Basin’s river systems. This is a sad state of affairs. Aboriginal people haven’t been approached to explore how they can manage the long-term protection of significant sites within these wetlands. When it comes to the protection of the environment and our culture and heritage, our voice is being left out. For too long our lands, our waters and our resources have not been used sustainably. Our people are suffering because we can no longer access the water that we have traditionally used. Our culture and our countries’ environment are being destroyed. Thankfully, when it comes to water at least, Australia as a nation has more recently come to realise the errors of its past and introduced two key pieces of legislation. In 2004, faced with the prospect of climate change and its history of mismanagement, the Australian Government, together with the states and territories, commenced the most significant water reform in the nation’s history. They introduced the National Water Initiative (NWI), which explicitly recognises the need to identify Aboriginal water values and which I discuss Phil Duncan in greater detail later.

40 DECEMBER 2011 water

The Murray-Darling Basin Then in 2007, the Australian Government introduced the Water Act, the principal focus of which is the allocation of water resources in the basin area of Australia’s most iconic and largest river system, the Murray-Darling. The MDB covers an area more than four times the size of the United Kingdom, and incorporates the traditional lands of at least 34 Aboriginal nations, including my own, the Gamilaroi/Gomeroi. The Aboriginal peoples of the Murray-Darling Basin continue to maintain strong connections and relationships to our traditional lands, waters and natural resources. The reforms planned for the MDB present a real opportunity for Australia to recognise and learn from our peoples’ traditional ecological knowledge and connections to our countries. For our peoples, it also presents an opportunity to right some of the past injustices and ongoing inequities suffered by the Aboriginal peoples of the Basin. As is recognised in the United Nations’ Declaration on the Rights of Indigenous Peoples, we have a right to our traditionally owned lands, waters and resources, and a right to maintain and strengthen our relationships to them. We also have a right to redress and compensation for those lands, waters and resources that have been taken from us without our free, prior and informed consent. We recognise and reaffirm these rights as the principles for improved water governance and integrated water management in Australia.

The First Peoples’ Water Engagement Council and the Way Forward The First Peoples’ Water Engagement Council (FPWEC) was established in 2010 by the National Water Commission (NWC) to provide advice on Indigenous water issues. The Council is calling for recognition of the inherent rights and entitlements Aboriginal peoples have to water. It supports the Aboriginal nations of the MDB in calling for Aboriginal water allocations for ‘cultural flows’ and economic benefits. These water allocations are rightfully ours and must be legally owned by our peoples. Allocations must be of sufficient and adequate quantity and quality to improve the spiritual, cultural, environmental, social and economic condition of our peoples. We must also be free to determine how we use our water – our connection to our water and our countries are complex and can only be determined by us. We don’t want all the water. We don’t want to destroy irrigation and farming, and the rural economies that support rural labour markets. We don’t want to deprive the environment. We simply want our fair share. Similarly, our rights and entitlements can no longer be relegated to, or confused with, the needs of the environment. In this age, the archaic and frankly offensive view of our peoples as part of the landscape cannot be used to undermine or limit Gwydir Wetlands in New South Wales contain our rights. important Aboriginal cultural heritage sites.

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An intricately carved piece of bark. In addition to our rights to water as Indigenous peoples, as citizens we have rights to water for domestic purposes. As former United Nations Secretary General Kofi Annan has said: “Access to safe water is a fundamental human need and, therefore, a basic human right”. This right belongs to all and we as citizens have a right to enjoy it in addition to our specific rights to water as Indigenous peoples.

The National Water Initiative

Governments must also address the impediments our people face in accessing our rights and entitlements to water. These barriers can prove insurmountable where basic infrastructure and capacity to navigate bureaucratic pathways is limited or lacking. Where impediments exist, the mere recognition of our inherent rights and entitlements alone is not enough. Rights and entitlements that are given without practical support for accessing those entitlements are just symbolic gestures.

While NWI parties have made progress in identifying all water user requirements and values, significant opportunities remain to:

At a time in Australia when the Commonwealth Government has allocated billions of dollars to water reform, we are asking that some of those funds be spent assisting Aboriginal peoples with access to their rightful water. We encourage the governments of Australia to listen and learn from our country’s first peoples for the benefit of the Murray-Darling, other waterways and our environment.

In 2004 all Australian governments signed the world’s best practice blueprint for water reform – the National Water Initiative (NWI). The NWI explicitly recognises the need to identify Aboriginal water values, their water requirements and water provision for current or future native title claims.

• More effectively engage and consult with Aboriginal communities to better account for their water values and requirements in water planning; • Encourage greater Aboriginal leadership in water planning and management issues. Aboriginal communities and groups are often left out of the planning process, or not adequately consulted. As a result our needs, values and water uses are not being recorded and considered alongside others. This can erode confidence for both our people and other users, and undo all the effort that goes into making a water plan.

The Rio Earth Summit’s Convention on Biological Diversity and the Ramsar Convention on Wetlands both make it clear that Indigenous knowledge and participation in resource management is to be both respected and encouraged. Australia’s own National Water Initiative includes similar stipulations. Good work has been done in this area. The NWC has established the First Peoples’ Water Engagement Council and the Murray-Darling Basin Authority is consulting with the confederated bodies of both the Northern and Southern Aboriginal nations of the MDB. However, when it comes to opportunities for Aboriginal people to engage meaningfully in the management of water resources, there is sometimes a chasm between perception and reality. The Aboriginal people are committed to the cause. The data from the last Census clearly showed that nonAboriginal people are leaving rural and remote communities, while Aboriginal people are staying. They are staying because these are our traditional lands and environments. The population shift makes it imperative that Aboriginal peoples be engaged as equal stakeholders to ensure the river systems are alive and well for our future generations. Water is critical to keeping rural economies alive. In NSW alone, outside the metropolitan regions, 76 per cent of Aboriginal employment is in the rural or primary industry arena. We need to ensure the long-term sustainability of these labour markets. Making us an equal stakeholder in water will only assist this process.

Phil’s grandfather, Leslie Duncan of Terry Hie Hie Aboriginal mission, standing in front of the tree he was born in, beside Terry Hie Hie Creek. A proud Gamilaroi/Gomeroi man, he is responsible for Phil’s teachings.

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Carved trees have been scarred by Aboriginal people for various purposes, from cutting out bark for a canoe to spiritual purposes. Very few carved trees remain today. They are said to be a history book and represent Aboriginal people’s soul. The governance structures for water planning frameworks rely on individuals representing our interests. They do not adequately account for our systems and customary law which dictate a broader base of involvement in decision making. Barriers to the effective implementation of NWI clauses include:

people be given greater opportunity to be part of decision making and water planning processes, including having:

• Lack of political and broader community understanding about Aboriginal water rights, values and management responsibility;

• Culturally appropriate resources to build capacity, including the provision of information about water resource management, water infrastructure, water sharing plans and markets and trading;

• Appropriate Aboriginal representation; • Difficulties in quantifying Aboriginal water requirements; • Lack of understanding and support for Aboriginal people in the water planning processes; • Low levels of collaboration between Aboriginal people and water planning agencies. Even where Aboriginal cultural values are clearly identified, the identification does not lead to any additional water requirements beyond those specified for environmental needs.

FPWEC 2011 Biennial Assessment Submission The First Peoples’ Water Engagement Council (FPWEC) recently made a submission to the NWC’s review of the implementation of the National Water Initiative. It recommended that Aboriginal

• Sufficient time to provide input and make decisions within each catchment;

• Effective and collaborative partnerships. It also recommended that Aboriginal people have access to water through special Aboriginal water allocations for purposes to be determined by the Aboriginal people. These should include cultural and economic purposes. This could be achieved though special purpose Aboriginal Economic Water Allocations from the consumptive pool. Culturally informed environmental priorities would be addressed through a separate cultural flows allocation. We also proposed the establishment of an Aboriginal Water Fund or Trust to fund, coordinate and facilitate the acquisition and management of special Aboriginal Economic Water Allocations. The allocation of water entitlements to facilitate economic development is a legitimate strategy to contribute to the Australian Government’s ‘Closing the Gap’ agenda. Where systems are fully allocated, a fund could be established to enable Aboriginal people to enter into and compete in the market. Where systems are not fully allocated, alternative approaches like the Strategic Indigenous Reserves being set aside in the Northern Territory may be more appropriate. The FPWEC is also committed to hosting a National Forum for Aboriginal Water in 2012. We hope to have all the key players from Aboriginal organisations and communities attend. At the forum we will be seeking to obtain a consensus on a range of water issues to present to the Australian Government.

Boobera Lagoon is considered to be the most important Aboriginal site in south-eastern Australia.

42 DECEMBER 2011 water

Please turn to page 54 for a general report on the 14th International Riversymposium.

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Productivity Commission – Final Report The Productivity Commission has released its much anticipated Final Report of its inquiry into Urban Water, commissioned by the former Federal Assistant Treasurer, Nick Sherry. AWA National Manager – Policy, Andrew Speers, outlines the key findings of the inquiry. At least in part, the inquiry was stimulated by the experience of drought and governments’ and utilities’ responses to it, and by the challenges posed by population increase. The Productivity Commission was also interested in the issues surrounding the ageing of infrastructure. The Commission argues that faced with these challenges, responses have generally been directed to increasing the diversity of supply sources – and commonly, at least in capital cities, have included major investments in desalination plants, and reducing demand through community education and water restrictions. It is the Productivity Commission’s view, however, that some investment in desalination may have been premature, leading to costs being incurred that may not have been necessary, and that restrictions are a blunt instrument that may impose significant costs on consumers and the community more broadly. For the Commission, such misdirected investment results from a lack of clarity in the objectives of water utilities, and flaws in governance arrangements. The Commission argues that utilities are often faced with multiple and conflicting objectives and, as a result, are not necessarily focussed on core activities and responsibilities. Reducing demand through restrictions is not necessarily the response that a commercially oriented utility would always take, for example. Further, the achievement of objectives has at times been distorted by government policy making, carried out in a manner that would not apply to a privately owned utility. The Commission’s primary recommendation is that the objectives of utilities be clarified. It recommends that the following be considered as a model: The primary objective of the urban water sector is to provide water, wastewater and stormwater services in an economically efficient manner so as to maximise net benefits to the community. A corollary of the introduction of clearer objectives is that boards overseeing utilities should be selected on merit and free from political interference. It is the Productivity Commission’s view that merit-based boards armed with clear objectives should operate in a commercial manner in the best interests of consumers and shareholders.

Approaches to Regulation One interesting aspect of these proposals is that the economic regulatory environment that has been established as a critical component of corporatisation of government owned water utilities – such as IPART (NSW) and ESC (VIC) – could adopt a more light-handed approach to regulation. The Productivity Commission argues that the monopoly prices such regulators were established to control are unlikely to occur, especially if soundly based boards and objectives are set in place. Thus, a

44 DECEMBER 2011 water

Australia’s Urban Water Sector

more ‘light-handed’ approach could be adopted which would see regulators periodically reviewing prices, rather than setting them. With regard to restrictions, the Productivity Commission sees a case for not imposing restrictions except in the case of emergency. The Commission cites data that suggests that the costs of restrictions can be measured in the order of $1 billion+, and that just with regard to the value of foregone water sales in a selection of capital cities. The Commission also refers to the community costs that are incurred because, for example, parklands or gardens are not watered. These costs, the Commission suggests, are ones that the community may have been willing to meet had it had that option. The Commission also cites data suggesting that the cost of subsidies for water-saving devices – for example, front-loading washing machines – has been very high in comparison to the volume of water saved and suggests that such subsidies not be provided unless there is a compelling economic case for doing so (e.g. the cost of subsidies is less than the cost of augmenting water supply, assuming similar volumes of water are saved/produced).

Water Security In making these observations, the Productivity Commission recognises that water security is an issue. Population increases and the risk of future droughts will mean that additional supply sources will be needed, particularly if the more dire climate change predictions come to pass. The Productivity Commission argues, consequently, that no water sources should be placed off limits by governments, and strongly recommends that governments lift bans that have been imposed on options such as recycled water and inter-basin transfers. Moreover, the Commission believes that structural reforms might improve decision-making with regard to system augmentation. Thus, for example, one of the four options outlined in the Report would see retailers/distributors becoming responsible for the commissioning of new water supplies from organisations – government or private – able to provide the required supplies. Productivity Commission Inquiry Report Volume 1

No. 55, 31 August 2011

Other issues, such as consumer protection, affordability of regional urban water reform and other topics are covered in the Report. AWA may report on these as they develop in future. The Productivity Commission’s Report has been formally delivered to the government, and released by it within the statutorily required period of 25 sitting days. It will now be up to Government to determine its response to the Report. A copy of the Report, which examined opportunities for efficiency gains within the sector, is available on the Commission’s website: www.pc.gov.au.

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conference reviews AWA’s 2nd National Water Leadership Summit From 2–3 November, AWA hosted its 2nd National Water Leadership Summit. This seminal event on the AWA calendar showcases leading-edge thinking about the direction of the Australian water sector from some of the industry’s stars. Andrew Speers, AWA National Manager – Policy, reports. The Summit began this year with a dinner with delegates hearing a candid and forthright speech by Kim Wood, soon to be former Managing Director of Allconnex Water. Kim described the events that led to the dissolution of Allconnex, how this affected him and his employees, and the lessons that were learnt. There was extensive and positive feedback about Kim’s presentation, who will shortly take up a role as Managing Director of Hunter Water in New South Wales. The dinner was kindly sponsored by Trility. The following morning a working breakfast sponsored by CSIRO was held where the Chief Executive of CSIRO, Dr Megan Clark, launched that organisation’s new book: Water: Science and Solutions for Australia. Said Dr Clark: “Australians have always had a strong sense of living in a dry continent, and have a long history of adapting to the extremes of floods and droughts. It is no surprise that our society is increasingly seeking information about the challenges of securing water resources for all users, especially with prospects of growing use of water and changing climate. This book seeks to provide a bridge from the peer-reviewed scientific literature to a broader audience of society while providing the depth of science that this complex issue demands and deserves.” A free copy of the book can be downloaded from: www.csiro.au/resources/Water-Book.html

and search for Hanson-Young). Dr Clark then returned to give a keynote address on the role of research and development in the management of water issues in Australia. Dr Clark outlined some of the climatic conditions and extremes predicted for Australia in future, and called for a coordinated national approach to environmental research in this country. Delegates were then privileged to hear from Governor Christine Todd Whitman, head of the Whitman Strategy Group, former Governor of New Jersey and former Administrator of the United States Environmental Protection Agency (USEPA). Governor Whitman provided an international perspective of the challenges the globe faces in water management, the issue she believes is the most pressing environmental concern in the 21st century. Her speech ranged from the macro-challenges of climate change and water security to the suburban challenges of infrastructure investment and maintenance. Governor Whitman made particular mention of Australia’s water expertise and encouraged Australian practitioners, both private and public, to take this expertise to the world. A copy of Governor Whitman’s speech is available on the AWA website. Delegates next heard from James Cameron, Chief Executive Officer of the National Water Commission, who spoke about the direction of water reform in Australia, both rural and urban. The National Water Commission has been at the forefront of water reform in Australia over the past five years, and is responsible for overseeing progress in the implementation of the National Water Initiative. James spoke about the common themes emerging from several key reports recently released, including the Productivity Commission’s inquiry into Urban Water (see separate article, opposite) and the National Water Commission’s own Urban

The National Water Leadership Summit was formally launched by the Minister for Sustainability, Environment, Water, Population and Communities, Tony Burke. Mr Burke provided a well-considered and structured overview of the Government’s position with regard to the management of rural water, particularly with respect to the Murray-Darling Basin Plan, the release of which is imminent. Delegates then moved to the formal conference room, where the day’s first speaker was Greens Senator Sarah Hanson-Young. Senator Hanson-Young reiterated the Greens’ commitment to the sustainable management of Australia’s water resources. A copy of her speech is available online (visit the AWA website

Delegates mingle at the reception, held at the Hyatt Hotel in Canberra.

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conference reviews

Governor Christine Todd Whitman spoke of global challenges in water management. Water: Future Directions and its 2011 Biennial Assessment. He spoke also about future reform priorities for the urban water sector which included, but were not limited to, clarifying the sector’s objectives, reviewing the effectiveness and flexibility of regulation, improving the focus on the customer and fostering community engagement, and stimulating the development of more liveable cities. The next session dealt with the private sector. Two speakers, Roch Cheroux, CEO of Degrémont, and Eamonn Kelly, General Manager Water, Thiess Services, discussed the role the private sector could play in future water markets in Australia. Roch’s presentation reflected on his experience in Chile, where he was involved in taking a formerly government-owned utility through to privatisation and the benefits that delivered to consumers. Eamonn discussed how to foster innovation without encountering undue risk. In particular he stressed a continued focus on safety, the development of shared objectives, clear governance arrangements and the sharing of risks and rewards. At the end of the pre-lunch session, AWA and its project partner, Deloitte, released the State of the Water Sector

Survey final report, which is subtitled The View from the Top. This report took highlights from the quantitative analysis released at the 2010 Summit, and expanded on the results through qualitative analysis of issues based on interviews with water sector leaders carried out over the past 12 months. This produced some results that at times reinforced accepted wisdom and at other times challenged it, but at all times it makes interesting reading. The report is complemented by statebased analyses of the qualitative data emerging from the Survey. These reports are all available for free download from the AWA website: www.awa.asn.au under the News & Advocacy tab. The after-lunch session dealt with the challenges of climate change. The first speaker was Professor Robert Hill, Adjunct Professor in Sustainability, US Studies Centre at the University of Sydney and Chairman of the Australian Carbon Trust, who spoke with great passion of the threat of uncontrolled climate change, the need to develop adaptation strategies (despite his earlier resistance to this approach, which, while Minister for the Environment, he felt represented a form of capitulation) and some of the opportunities. Professor Hill’s speech was followed by a practical example of responses to climate change delivered by Sarah Dinning, Group General Manager, Corporate Development, Sydney Catchment Authority (SCA) and Noni Shanon, Special Counsel, Norton Rose Australia, who has been advising the Authority. This presentation dealt with the SCA’s proposals to explore opportunities to participate in carbon offsets through an eligible carbon farming initiative, based on land owned and managed by the SCA.

Minister Tony Burke gave an overview of the Government’s position regarding rural water management.

46 DECEMBER 2011 water

The 3rd National Water Leadership Summit will take place in Canberra in early November, 2012.

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conference reviews International Desalination Association (IDA) Congress Written by Diane Wiesner The 15th IDA World Congress on desalination and water reuse, Desalination: Sustainable Solutions for a Thirsty Planet, was held at the Perth Convention Centre from 5–9 September 2011. The conference attracted close to 1200 attendees from across the globe, with over 90 exhibitors, 270 oral presentations and 140 poster technical papers. Topics ranged from costs, finance and commercial issues through to membrane technology, thermal plants, membrane desalination O&M, health, environment and waste management, and the latest research in membrane, thermal and hybrid applications. Drinking water, water reuse and industrial uses were examined, including the growing application of desalinated water in the oil and gas industry.

Keynote Address The keynote address was given in a pre-recorded video by Sir Richard Branson, founder of the Virgin Group, from his hideaway on Necker Island. Sir Richard spoke about the critical importance of water, not only to island communities such as his own, which lacks freshwater, but in the developing world as populations multiply. With 97.5% of total global water locked up in solid form and only 0.75% available as freshwater for use, Sir Richard encouraged those in the desalination industry to keep the sustainability message to the fore while providing water for a thirsty planet. He emphasised the importance of new technologies such as reverse osmosis for desalination by referring to the dependence he himself has for water on the functioning of the desalination plant on his island. Sir Richard’s presentation was followed by a Plenary led by Sue Murphy, CEO of Water Corporation, principal conference sponsor and the first Australian water utility to commit to large-scale desalination supply. Ms Murphy summarised the Australian experience with desalination as new benchmarks for environmental performance having been set, reducing impact of intakes and outfalls, and plant location. Carbon footprint has also been significantly reduced by extensive purchase of wind-powered renewable energy to offset energy consumed. Last year, the plant contributed 52 megalitres (ML) of desalted water to Perth’s supplies, well beyond its contracted capacity of 45 ML/year.

Commercial Issues Session The main thread shared by papers in this session was that project financing, particularly in current markets, has become difficult and the industry needs to be prepared to face new and more stringent rules in project financing and delivery. Increasing privatisation in desalination and water reuse has been a key element to the booming developments that have been observed in the last decade, and has contributed to diversifying the technology and identifying correct trade-offs between reliability, technical risks and price competitiveness. A useful paper delivered by Rob Huehmer: Cost Modeling of Desalination Systems (authors: Kenneth Moore, Robert Huehmer, Juan Gomez and Jason Curl) identified several commercially available and/or non-proprietary desalination cost models currently in the desalination market. The cost models most frequently quoted in the grey literature are WTCost©, and cost curves contained the publication entitled Desalting Handbook

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for Planners. Other models described include Global Water Intelligence Desalination SWRO Cost Estimator, Desalination Economic Evaluation Program (DEEP), AUDESSY, WRA models and the Kawamura model. A comparison of commercially available models identified the similarities, weaknesses and strengths of the models, and compared the results over a range of capacities. In delivering the presentation, Rob nominated three classes of models – the empirical, parametric and, his favoured model, an automatic design and cost program. His criticisms of the empirical model were that too many variables were involved, which did not lead to greater reliability. He considered the parametric model to be OK, but was critical of the amount of data it required and the consequent complexity. He saw the future lying with automatic design and cost platforms. However, there were difficulties in trying to convince clients to adopt it. These ranged from the suspected limitations to the IT involved from prospective clients, insufficient engineering sophistication, union truculence, and clients’ attitudes to the use of automatic cost models. The presentation brought forth some spirited discussion. One speaker pointed out that the model was not a reliable approach for thermal plants and considered it should be confined to RO systems. Another stated that inputs are different for different locations, so the method has inherent limitations. Session co-chair Graham Dooley pointed to the key role of the client in any commercial arrangements and the importance of a positive and productive relationship between the client and participating partners. A Panel Discussion led by the co-chairs, Graham Dooley and Ghassan Ejjeh, followed the papers. Topics included: • The future of the integrated water and power plant project (IWPP); • Fewer emerging forms of investor financing for smaller-scale projects; • General economic crisis; • General economic crisis: effect of the Arab Spring. Ghassan Ejjeh introduced the topic for the Plenary: Is Privately Financed Desalination/Water Reuse Still Relevant/Possible?. He began by focusing on project risk in the context of the recent financial crisis, which has led initially to reluctance and now abandonment of long-term finance to major water supply projects by banks and financial institutions; the Bahrain STP went ahead, as did the Abu Dhabi-Suez project, but many were shelved. He then drew attention to the dislocation occasioned by the “Arab Spring” series of uprisings in North Africa, which had put a number of major projects on hold.

NCEDA CEO Neil Palmer being interviewed at the Congress.

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conference reviews • Bundling projects – a number of smaller projects with mixed sizes and risk profiles are put together into a package which is more attractive to banks.

Energy Sources, Uses and Efficiency Session Energy recovery from the SWRO brine stream has been one of the most sensational advances in seawater desalination in the last decade. This innovation greatly contributed to improved sustainability of water solutions, decreased energy and carbon footprint and decreased water cost. Energy footprint is now one of the major challenges for seawater desalination. This segment of desalination technology is in constant development and is a key to high efficiency, reliable performance and successful operation of SWRO processes. One of the most interesting and potentially valuable initiatives discussed was a paper by a Japanese team on Solar Thermal Energy Seawater Desalination (authors: Toru Kannari, Yoshiaki Miho, Yuji Saito, Dr Rencai Chu, Professor Yoshiharu Horita). Toru Kannari, who delivered the presentation, began by backgrounding the difficulties associated with delivering desalinated seawater using solar energy. These range from problems with constructing and maintaining solar facilities to those associated with fine-tuning operations and building stability into the system.

Delegates enjoy an Australian cultural evening. Unlike energy projects for which customers were prepared to pay for supply, water customers persisted in the view that water should be free or low cost. As a result, commercial suppliers of water are ever inclined to keep costs low so as to maintain relationships with them. This means that they are not able to offer the same level of returns on water projects to funding bodies, with the consequence that water projects are less attractive to those seeking a reliable and increasing return. A series of panellists followed, with the highlight being the comments by Graham Dooley, who focused on the financing difficulties experienced by smaller plants. He pointed out that there was a perception of capital scarcity in Australia (because of the issues previously identified by Ghassan Ejjeh) associated with the returns available to funding bodies from comparable infrastructure investments. Graham quoted a 15% internal rate of return (IRR) for water projects competing against 35% and above for mining-related infrastructure. He pointed to the special funding difficulties faced by small water projects, which are inherently more risky to the financier, and which were turning to seek equity partners who would share project risks and funding. He identified three forms of equity being considered: • Include partners with strong balance sheets in return for giving up equity in the project; • Private equity finance with entities such as superannuation funds, which are looking for better returns than those offered by bonds. For these partners, the risk equation has to be structured to suit them, not the technology and its limits; this puts an understandable pressure on project participants, which can actually produce a superior outcome;

Having identified current limitations, Mr Kannari then moved to describe a promising new solution to raise the operating efficiency of solar desalination systems by way of the addition of a thermoelectric generator (TEG) module. In this configuration, solar heat is collected and concentrated in the solar thermal collector and used to generate steam, which is then employed as the heat source for the thermal desalination unit. To optimise the system, TEG modules are attached across almost the entire surface of the heat exchange wall of the steam generator. A TEG module is composed of multiple elements, each of which consists of two different semi-conducting materials connected as a “thermocouple” to convert heat directly into electricity. The vaporisation system used in this configuration can concurrently generate steam and electricity without the need for a steam turbine generator. Part of the electricity generated by the TEG module is used for operating the heat desalination unit and the surplus electricity generated can be supplied directly to the grid or to the RO desalination plant for further production of water. Since the system has no moving parts, is easy to operate and highly reliable, it is expected to be invaluable for satellite systems of 5,000 or 20,000 tons/day capacity. Furthermore, the combination of this TEG technology with a trihybrid NF/RO/MED is expected to be more efficient in the utilisation of heat and electric power, and is considered to be one of the most suitable systems for next generation seawater desalination plants driven by solar thermal energy.

Intakes and Outfalls Session Seawater intake design needs to adapt to increasing environmental sensitivity applied to desalination projects worldwide, and new technologies are developing in order not only to improve seawater abstraction reliability and quality of the seawater feed, but also to improve the environmental impact associated with the seawater abstraction and discharge. Seawater abstraction systems are of vital importance and are a major contribution to desalination costs and reliability of operation.

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conference reviews Robert Maliva (US) looked at Injection Well Options for the Sustainable Disposal of Desalination Concentrate (authors: Dr Robert G Maliva, Dr Thomas M Missimer, Russell Fontaine), drawing on the range of options and designs in plants across the US, from beach wells to intake tunnels similar to those common in Australia.

Membrane Technology Session Another interesting paper that attracted a sizeable audience was titled Utilising Nanotechnology to Enhance Membrane Performance for Seawater Desalination (authors: Christopher Kurth, Dr Robert Burk, Jeff Green). Beginning with a quick overview of the history of the development of nanotechnology, Christopher Kurth explained the principles behind the operational success that led to the synthesis of the first nano-particulate membranes for RO application. The increased permeability to water that arises with these membranes was found to be associated with the roughness of the nano-particulate surface and is essentially due to the increased surface area available to the water molecules. Delving deeper, a second layer of structure within this roughness was shown to enable the water molecules to travel through. The next step towards developing a commercial product for seawater desalination plants was to produce a nano-composite membrane on top of a supportive polymer layer. Rejection issues and fouling complicated the development of the final product and the team set out to work out where foulants and other particles were lodging in the nano-membrane. Defect channels in the membrane – areas where nano-particulate aggregate had formed during the initial membrane fabrication – appear to be the source of the problem. Continuing research in the fabrication process is expected to lead to further improvements to flux and increasing sulphate rejection. Currently the team is targeting the finalisation of their research to bring it to commercial production with field validation via pilot modules, and expanding the product line so that it could yield membranes specifically designed to suit source water and/or product application.

Materials Session For those planning, designing, constructing and operating desalination plants, this session provided a list of what to do and not to do when selecting materials and seeking to maintain them in a membrane seawater desalination plant (SWRO) in Australia. Since it was Australia’s first plant and has now been operating for five years, a summary of lessons learned from Perth 1 was presented by Tako Heiner (co-author: David Parracinii). He began by stating that the goal of his presentation was to “raise awareness” and for others to learn from the experiences being detailed. While responsibility for Perth material selection tends to be placed ultimately on the designer, the owner is concerned about costs, the operator about functionality, while the constructor has a range of other priorities. For the Perth SWRO, minimising crevice corrosion as occurs with continual exposure to saltwater and air and being equipped to resolve it when it occurs, without loss of production, was a priority in selecting materials and components.

NCEDA researchers at the IDA World Congress. • Non-return spring collapse where the mechanism was found to be galvanic coupling; • Rack inlet valve showed seal faces and stem crevice corrosion. The conclusion: no material is, or is likely to be ideal in seawater because of the inherent variability of the medium in oxygen, salinity and other water quality criteria. A different emphasis, from the Sydney Seawater Desalination Plant, was provided by Andreas Broeckmann (co-authors: Stephen J Roddy, Peter Eccleston). This paper discussed the selection of essential process systems and elements for the plant, rather than the materials components themselves. At Sydney SWRO, elements identified as likely to be the source of problems were seawater, 1st pass concentrate and the permeate. For the intakes, biological growth and dealing with chlorinated seawater were identified as factors in materials selection. For the pre- treatment systems, the issues were again chlorinated seawater, spray and splash, varying fluid levels and aeration. Andreas commented that coatings for concrete structures and metallic equipment may not be as protective against corrosion as just stainless steel. For the RO system, the concerns were rack design, the operational envelope, performance and energy consumption. For critical process components, the use of super duplex steel was deemed essential, despite cost, due to its corrosion resistance and design flexibility. The pumps need hydraulic testing to ensure optimal performance. Vibration and noise continue to be difficult to manage. Other points made included: casting quality is critical and welding needs to be of a high standard; poor work needs to be identified and corrected prior to moving onto the next step to avoid subsequent downstream failures; and tanks for chemicals and for storing treated water, in particular, need quality welding followed by integrity tests and QA. The final point emphasised was the need for robust and careful management, with attention to detail at all stages.

Unassigned/General Papers

• Seawater intake grille SAF2205, heads of bolts hollowed out;

This category captured an eclectic mix of papers that did not fit clearly into other sessions. The most interesting group identified a new market – the oil industry – for future application of desalination technology. The first, titled Turning Water into Oil: Desalination a Process to Enhance World Oil Resources, was given by Dale Williams, LoSal™ EOR Facilities Program Manager for BP in the UK.

• Non-return valves showed perforation through the body after three years’ service;

The purpose of Dale’s paper was to highlight the existence, nature and potential available to the desalination industry

Types of failure observed in the five years of operation include:

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conference reviews from collaboration with the oil industry, where only the larger companies have the capacity to build in-house expertise in the technology. To begin, he outlined the mechanism and conditions under which low-salinity water augments the oil recovery process. Currently, global oil production relies heavily on the injection of water into oil-bearing formations to maximise the resource recovery from the oil reserves contained within these reservoirs. Advances in fundamental understanding and oilfield applications have demonstrated that the efficiency of oil recovery in this way is consistently and significantly enhanced by reducing the salinity of the injected water. However, the offshore locations of many oil fields, and the need to sustain sources of potable quality water in regions of land-based oil fields, mean that for the oil industry to practically and responsibly produce the additional, valuable energy reserves will require the desalination of sea, brackish or aquifer waters. Descriptions were given of how the desalination process needs to integrate with typical water treatment and injection system designs. Information in Dale’s paper summarised the results of screening studies completed to identify the desalination technologies most appropriate for application in the oil industry. In concluding, he gave an overview of the status of the oil industry’s full-scale implementation of this technology, the limits to wider application, and the key challenges to its broader uptake at mature and newer oilfields. The second paper was delivered by Lisa Henthorne and titled, Desalination in the Oil Industry – Perfecting Enhanced Oil Recovery Using Optimised Water Quality (authors: Lisa Henthorne, Meghan Hartman and Andrea Hayden). Specialised nano-filtration technology has been used to produce lowsulphate seawater for water-flooding to improve oil recovery in offshore oil fields since Marathon Oil first used their patented technology on the Brae Oil Platform in 1988. Sulphate in seawater is problematic due to its low solubility when coupled with barium and strontium salts in some oil reservoirs and due to the potential for bacteria to reduce sulphate to hydrogen sulphide within the reservoir. Since the Brae installation, more than 44 sulfate removal process (SRP) systems have been installed on offshore platforms, producing over 318,000 m3/day of water. Today, oil companies are stretching further to produce more oil from existing fields, and considering that globally the rate of average recovery of oil in place hovers around 35% from existing fields, improved recovery can be justified by current oil prices versus base costs of recovery. Other than sulphates, the ion composition of water used in water-flooding of oil reservoirs has received little attention. Water quality manipulation has recently emerged as an influential method to increase oil recovery. By targeting injection water composition, a number of benefits have been demonstrated, particularly in chemical-enhanced oil recovery (CEOR) and lowsalinity water-flooding. Lisa then presented information from three case studies of offshore projects, which demonstrated the impact and benefits of customised water quality on project economics and potential incremental oil recovery, based on modelling the water treatment systems. These cases included: • Low salinity and sulfate, medium ratio divalent/total cations; • Medium salinity, low hardness; • Low salinity and hardness, high ratio divalent/total cations.

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In CEOR applications, customised water quality can improve conformance, reduce polymer costs and reduce alkalinityrelated scaling. In low-salinity water-flooding, specific ion compositions can be created from seawater or brackish water to alter the wettability of the reservoir, resulting in higher oil recovery. Attention to the divalent ion concentration is critical in low-salinity floods to prevent clay deflocculation in sensitive reservoirs. Combining low-salinity injection with CEOR may offer a two-fold benefit, although it needs to be remembered that each oilfield is unique and not all fields are suitable candidates for improving recovery by altering the injection water composition. Achieving optimum blends of ions to realise maximum recovery is a function of carefully choosing membrane and polishing technologies, and marrying them with adaptable pressure centres for power efficiency. While the offshore industry is familiar with SR membranes, innovative membranes and ion selective systems can be designed to customise water quality cost effectively, thereby expanding the operator’s ability to enhance recovery.

Recycling and Reuse Session A useful paper for utilities looking at issues associated with increasing use of recycled water in their facilities was delivered by Greg Wettereau from California, entitled Selecting the Optimal Source Water for Indirect Potable Reuse in Los Angeles, California. Greg explained that in endeavouring to maximise the use of recycled water, the Los Angeles Department of Water and Power (LADWP) is working on implementing indirect potable reuse for their Donald C Tillman Water Reclamation Plant. The facility aims to utilise advanced water treatment processes, consisting of microfiltration (MF), reverse osmosis (RO), and advanced oxidation to produce potable quality water for groundwater recharge. To plan for this initiative, LADWP has been conducting 15 months of pilot testing in order to optimise operating conditions and evaluate alternative processes. Of particular concern is choosing the best method of disinfection for biofilm growth control ahead of the MF and RO membranes, as well as the best source of supply when both secondary effluent and tertiary filtrate are available. The findings presented described bench-top and pilot-scale studies of the impact of different source waters and preliminary disinfection approaches on disinfection by-product formation, including NDMA and THMs, and on membrane performance. Results of the bench testing showed that using secondary effluent resulted in lower NDMA formation from chloramination, when compared with chloraminated tertiary effluent. Both sources produced no NDMA when free chlorine was used as the preliminary disinfectant; however, THM formation exceeded the 0.08 mg/L goal when greater than two hours of free chlorine contact was used. Testing now aims to confirm whether consistent differences can be documented in NDMA formation between secondary effluent and tertiary effluent, whether use of sequential chloramination will consistently control both NDMA and THM formation and the impact of the differing disinfection and source water approaches on performance of MF and RO membranes. Another paper returned to the oil-petroleum industry theme: Treatment and Reuse of Petroleum Refinery and Municipal Wastewaters – Membrane Pilot Results, presented by Chiew Hiet Wong. Chiew introduced the project by describing the Northern Water Plant at the Shell Geelong Refinery in Greater Melbourne. The plant is designed as a dual membrane water

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conference reviews recycling facility utilising activated sludge, ultra-filtration, reverse osmosis, UV and chlorine disinfection to treat municipal sewage and process water from the refinery to yield fully validated Class A recycled water. Unlike most other dual membrane water recycling plants operating in Australia and overseas, petroleum refinery process water will make up 25% of the total influent, which has elevated levels of refractory organics, including BTEX, phenolic compounds, PAH and TPHs. Chiew referred to past projects which have identified that hydrocarbons such as phenolic compounds could cause irreversible fouling on the RO membranes, and spoke about measures taken to minimise this same problem, including the specifics of the design of a pilot plant to identify the causal agents by autopsy of the membranes and subsequently test a range of measures to reclaim the membranes. More specifically, membrane fouling was observed and both chemical cleaning and membrane autopsy were conducted to test the effectiveness of cleaning protocols. For the UFs, the observed fouling could be correlated to high organics and high solid loads events, which related to operation of the upstream biological treatment plant. Nevertheless the operating flux rates of 47–50 LMH could be maintained with the backwash and maintenance wash protocols employed. Clean-in-place (CIP) results demonstrated that membrane performance was fully recoverable. For the RO system, fouling was also observed, especially on the Stage 2 membranes. While conclusions could not be drawn on the exact nature of foulants, a number of contributing factors could be identified, including elevated

levels of refractory organics, and iron, calcium and magnesium salts in the phosphate and fluoride forms. The CIP conducted suggested that the observed fouling was mostly reversible. As a result of these pilot tests, the team reported that a fullscale plant design would chemically remove phosphorus in the biological plant. By operating the RO system at an alkaline pH range of 7.3–8.0, the solubility of organic compounds would be significantly higher, thereby minimising the associated fouling. In addition, fouling-resistant RO membranes with thicker feed spacers and daily flushing protocols would mitigate the risks of membrane fouling. Overall this study demonstrated how important it is to undertake a pilot study to examine concept feasibility of difficult-to-treat industrial wastewaters to enable beneficial reuse, a lesson that needs to be writ large for all treatment plant planners and promoters.

Conclusion The technical program was followed by an Awards Ceremony where cash prizes each valued at $US 5,000 were presented to four of the most outstanding oral presentations and one for the best poster. A further $US 5,000 award was presented to a member of the IDA Young Leaders Program. AWA member Hiep Le, Principal Process Engineer with Osmoflow, was awarded the IDA’s ‘Emerging Leaders Achievement Award in Desalination and Water Reuse’. The final day of the conference featured a series of workshops and tours to of the event’s major sponsor, Water Corporation. More details are available at: www.idadesal.org. A CD of the Conference Proceedings may also be purchased from the site.

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conference reviews The Value of Rivers Discussions from the 14th International Riversymposium “The strength of the Riversymposium lies in its ability to bring together the usually autonomous sectors of industry, science, government, community and environment to enable knowledge exchange and integrated river basin management.” – Mr Barry Ball, Chair, Riversymposium Management Committee. From 26–29 September this year, over 600 delegates discussed, debated and shared their knowledge and experiences at the 14th International Riversymposium in Brisbane. Throughout the threeand-a-half-day program, delegates explored the economic, ecological, cultural and spiritual values of rivers.

Opening Ceremony Delegates fell silent as the sound of a single didgeridoo filled the room for the start of the opening ceremony. Kargun Fogarty performed a number of didgeridoo pieces, followed by indigenous songs related to rivers and water, before his official Welcome to Country. He then introduced an indigenous painting that he designed specially for the 14th International Riversymposium and invited selected delegates to give their thumb print to begin the completion of the painting. All conference delegates were then invited to help complete the painting throughout the duration of the conference. Mr Ian Robinson, Commonwealth Environmental Water Holder, officially opened the conference after reflecting on the devastation Australia has seen this year and stating that “rivers have a tremendous power to impact the lives of all of us”.

Delegates enjoy refreshments at this year’s Riversymposium. Experiments facilitated in the Rhine region by government organisations and knowledge institutes are enabling people to make their own flood-proof land use designs and are identifying innovative financing mechanisms for sustainable river basin management.

Need for Green The ‘need for green’ infrastructure in river restoration featured throughout the Riversymposium program. Sessions hosted in partnership with the Australian Society of Limnology explored ‘Engineering the Restoration of Rivers’ using soft approaches, and shared lessons learned through successful case studies of river restoration. The Australian chapter of the Society of Wetland Scientists hosted ‘Maintaining and Restoring Wetland Values’ sessions, where speakers delved into topics ranging from climate change to using stormwater for urban wetlands.

Quantifying Economic Value

Opening keynote speaker, Mr Ingwer de Boer, General Director of the Programme Directorate, Room for the River, of Rijkswaterstaat in The Netherlands, described the ‘Room for the River’ project, where a range of measures is being implemented to reduce the risk of flooding. The project is lowering floodplains, relocating dikes further inland, lowering groynes in the rivers and deepening summer beds, thereby taking a central role in the transition of water management practice from ‘fighting against water’ towards ‘living with water’.

A common theme of many presentations was the challenge of securing funding for restoration projects. In the feature session ‘International Carbon Markets and Market Based Instruments: Funding Catchment Priorities’, speakers discussed using markets to fund projects to restore nature, giving examples of nitrogen and salinity trading schemes. A case study demonstrated how Blue Carbon sinks can play a crucial role in maintaining climate, health, food security and economic development in coastal Australia. Market-based systems have potential to work where there is data, resources and trust among stakeholders. However, due to the challenging, dynamic and complex context of catchments, quantifying the economic value for accounting purposes is difficult.

Innovations in Flood-Proofing

Cultural Flows

Another Dutch example of the evolution of river basin management, from hard engineering to green infrastructure, was presented by Professor Toine Smits of Radboud University. Professor Smits described how managing rivers from an engineering approach resulted in increased flooding, deterioration of the fluvial system, and high management costs to river basin management focused on land use adaptation.

Mr Phil Duncan, Chair of the newly established First Peoples’ Water Engagement Council and Senior Policy Officer at the Aboriginal Land Council, told the story of his Song Line. He described the strong connection between Aboriginal peoples in the Murray-Darling Basin and their traditional lands, waters and natural resources. Mr Duncan, a member of the Gamilaroi/ Gomeroi Nation, argued the need for indigenous engagement in water planning, allocation of cultural flows, and indigenous access to the consumptive water pool for economic purposes. (See page 40 for an edited extract of his speech.)

Room for the River

Healthy Waters, Healthy Community

Delegates engaged by Ingwer de Boer’s keynote presentation.

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The spiritual and cultural values of rivers, wetlands and groundwater featured highly in the program. Speakers described the sanctity of rivers and waterways across the world, with their intrinsic links to creation stories, deep spiritual relationships with indigenous peoples, the land and waterways, and personalised experiences building identity and sense of place. The message was: If lands and waters are healthy, community is healthy.

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conference reviews ‘Soft’ Engineering Dr Guangchun Lei of the Beijing Forestry University, China, presented a case study of Poyang Lake in China. He described the decline of the lake’s health over the past 50 years from wetlands reclamation, water pollution and over-exploitation of natural resources. After devastating flooding in 1998, ‘soft’ engineering, including water and soil conservation through upstream reforestation and downstream wetland restoration, was adopted. The resulting improvement of water health increased biodiversity values and the lake’s ability to assist in flood mitigation.

Persuasive Articulation A workshop on ‘Challenges and Solutions to Riverine Ecosystem Services Assessments for Decision Making’ discussed methods for identifying, measuring and valuing the ecosystem services of improved river management. There are many beneficial private and public goods and services provided by riverine systems. For example, ensuring adequate environmental flows protects not only rare species, but also productivity, jobs, health and lifestyles, now and into the future. But action on ecosystem services is required now. Persuasive articulation of the benefits of these services is required for the development and implementation of effective policies and decisions for managing riverine ecosystem services across multiple geopolitical scales.

Paradigm Shift Professor Barry Hart of the Murray-Darling Basin Authority discussed the paradigm shift needed in the Basin’s water resources management if it is to meet the environmental water requirements of its key ecological assets and functions. For more than 50 years, management has been largely focused on the efficient delivery of consumptive water, particularly for irrigation. However, major changes in river operations and water resource allocation are now required to return consumptive water to the environment.

A Common Vision Dr Denise Reed from the University of New Orleans, US, explained that for 150 years the management of the Lower Mississippi River has focused on supporting navigation and limiting flood risk. However, this has disconnected North America’s largest river from its delta plain, causing the massive ecosystem degradation experienced in coastal Louisiana in recent decades. Dr Reed posed the question: Can we develop an approach to river management that balances the competing values of transportation, flooding and coastal ecosystem needs? Planning for future river management requires consideration of global trade, changes in runoff and agricultural production, and the needs of multiple users for clean, fresh water, without sacrificing the sustainability of a world-class ecosystem. Echoing the sentiments of Professor Hart, she concluded that the future of managing rivers requires policy, science, engineering and management to work towards a common vision.

2011 Riverprize Winners Delegates and invited guests enjoyed live entertainment and the presentation of the 2011 Riverprize winners at the Riverprize Gala Dinner. Awarded by the International RiverFoundation, the National and Thiess International Riverprizes provide recognition, reward and support to those who have developed and implemented outstanding, visionary and sustainable

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The proud winners of the 2011 Riverprizes. programs in river management. This year’s winners were Sunshine Coast Rivers Initiative, Queensland (National) and Charles River, US (Thiess International). • 2011 National Riverprize winner – Sunshine Coast Rivers Initiative, Queensland The Sunshine Coast Council and Partners demonstrated an impressive collection of river-health planning and on-ground achievements in six catchment areas, comprising approximately 5,000 kilometres of waterways across the Sunshine Coast region in South-East Queensland. Conducted by a collaboration of the Council, local community groups, industry, natural resource managers and other government partners, the community works to protect and improve the health of local waterways. The Initiative delivered outcomes via five themes: Science; Planning & Policy; Partnerships; Education & Advocacy; and On-ground Projects, with activities underpinned by constructive partnerships and an enterprising spirit. • 2011 Thiess International Riverprize Winner – Charles River, US Charles River Watershed Association (CRWA) was awarded the Thiess International Riverprize for outstanding achievement in river restoration. When the CRWA was founded in 1965, the Charles River commonly changed colour according to the colour of paint being manufactured on its banks. Today, the CRWA’s work has evolved from the health of the river towards urban design, sustainable infrastructure and elimination of barriers between water supply, wastewater and stormwater management. Its key achievements include the creation of the Charles River Natural Valley Storage Area; implementation of Massachusetts Water Resources Authority Long-Term Combined Sewer Overflows Control Plan; invention of SmartStorm®, a rainwater harvesting system, coupled with a stronger regulatory climate for rainwater recycling; and Blue Cities™ Initiative for water-sensitive urban development.

Study Tours As part of the Riversymposium program, delegates ventured off-site to visit flagship projects in South-East Queensland. They were treated to firsthand views of award-winning water sensitive urban design projects, impacts of the January 2011 floods, river restoration programs in the upper catchments and Brisbane City Council’s Norman Park 2026 project. After the success of the last two symposiums in Perth and Brisbane, the 15th International Riversymposium will be held in Melbourne from 8–11 October 2012. The conference theme will be: ‘Rivers in a Rapidly Urbanising World’. Visit www.riversymposium.com to view the 2011 proceedings and submit an abstract for the 15th International Riversymposium.

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LIfe CyCLe ASSeSSment Of tHe GOLD COASt UrbAn WAter SyStem Achieving a balance between opposing environmental impacts is a challenge D de Haas, J Lane, P Lant Abstract

Introduction

This study examined the urban water cycle of the Gold Coast region under two scenarios of infrastructure provision, namely: the ‘Traditional’ mix, as operating in 2007–8, prior to the commissioning of large-scale water recycling and desalination schemes in this region; and a hypothetical ‘Future’ mix that incorporated seawater desalination and water recycling (‘third pipe’ Class A+ to the Pimpama-Coomera area; and indirect potable reuse via a dam from the largest wastewater treatment plant in the area). For the ‘Future’ infrastructure scenario, the population base expanded by 2.6-fold compared to the ‘Traditional’ scenario benchmark (2007–8 operating data). By assumption, the projected future water supply needs of the region would be met largely by a combination of water recycling and desalination. Life Cycle Assessment (LCA) methodology was applied to these two scenarios in an effort to identify as broadly as possible the environmental impact potentials of adopting more energy- and materialsintensive future water supply alternatives in order to service a growing population.

Rapid population growth in the face of droughts followed by recent floods poses significant challenges for the urban water system in South-East Queensland (SEQ). Already it has resulted in substantial changes to the way water supply and wastewater services are configured and managed in the region. For example, in response to the potentially severe water shortages during a recent drought (2001–8), the Queensland State Government initiated the Western Corridor Purified Recycled Water (PRW) and Tugun Desalination projects, which were completed in 2009. Additional possible future water recycling and desalination projects have been considered to meet projected water demand under low rainfall scenarios.

The study found that the technologically more complex options of water supply (i.e. water recycling, desalination and even rainwater tanks) have the potential to increase environmental impacts on a ‘per unit volume of water’ basis in most impact categories (including ecotoxicity, human toxicity, global warming, ozone depletion and metals depletion), compared with the ‘Traditional’ supply via dams. Only eutrophication potential (through more advanced treatment and reduced nutrient load discharges) and freshwater extraction (through reduced reliance on dams) would be reduced, in relative terms. Achieving a balance between these opposing environmental impact potentials presents a challenge to urban water planners and operators.

The Western Corridor PRW scheme has the capacity to treat the majority of urban sewage in the Brisbane and Ipswich metropolitan catchments to a quality suitable for large-scale direct non-residential reuse. The treatment plants are also capable of providing for indirect potable reuse (IPR) utilising existing water supply dams. Similarly, although on a smaller scale, in the Pimpama-Coomera region of the Gold Coast, wastewater is treated to Class A+ recycled water quality, and piped directly to households and industry for reuse in toilets or irrigation. Another significant driver for future infrastructure development is the Queensland Development Code MP 4.2 (2008) requirement that all new households built in SEQ must have some form of on-site water supply that will offset the demand for mains potable water. The legislation only allows for a small number of possibilities to meet this requirement, and the likely result in practice is that new houses typically have a rainwater tank installed to capture roof runoff.

From a planning and operational perspective, there is a need for systematic assessment of the tradeoffs associated with choosing between alternative approaches to meeting water supply requirements. Life Cycle Assessment (LCA) methodology applies quantitative rigour to options analysis, taking a long-term view across a broad range of environmental impacts. LCA has been used to inform urban water cycle planning elsewhere in Australia (inter alia Lundie et al., 2004; 2005; Mrayed and Leslie, 2009) and internationally (inter alia Gaterell et al., 2005; Raluy et al., 2005; Gallego et al., 2008; Munoz and Fernandez-Alba, 2008; Friedrich et al., 2009). This study represents the first comprehensive application of LCA across the wide range of water supply and wastewater infrastructure options being considered in SEQ. The work has been supported and funded by the Urban Water Security Research Alliance in Queensland (see Acknowledgements).

Study Objectives Using the Gold Coast urban water system as an example, the objectives of this study were to investigate the following: 1.

The greenhouse gas intensity profile of the system and its infrastructure components;

The spread of system impacts across a wider range of life cycle categories (not only global warming), including an improved understanding of the metrics required to estimate those impacts;

Life cycle impact tradeoffs involved in choosing between alternative water supply options;

Key data gaps that should be priorities for further research; and

Overall assessment of the potential usefulness of LCA in planning decisions for such systems.

water

DECEMBER 2011 57

water resources Table 1. Water supply balance for infrastructure mix in each scenario.

Dam

WTP sludge to sewer

Urban Households

WTP

urban HH

tank

outdoor use

tank

20,000

20,000 570,235

140

377

Water Use – Residential

262

Water Use – Non-residential

115

140

377

137

141

Dam Supplies – IPR

Class B irrigation

Seawater Desalination

125

Rainwater (Household Tanks)

Class A+ Residential

1. Connected to mains water supply & some with rainwater tanks; not connected to sewerage 2. Including allowance for mains distribution losses

Ocean

Figure 1. ‘Traditional’ scenario urban water system.

Study Overview

Dam Supplies – Environmental

Biosolids to Farms

STP

Plants (WTP), supplemented by rainwater tanks on 15% of existing houses; and

Two scenarios were considered for the provision of water supply and wastewater services to urban communities in the Gold Coast region of SEQ. The infrastructure considered under each scenario was limited to those water supply and wastewater infrastructure types that are in use, or have been considered for use in the SEQ region.

• Sewage collection and treatment (four STPs), utilising 20% of secondary treated effluent for non-residential (mostly irrigation) reuse, and 100% of biosolids for agricultural reuse.

The ‘Traditional infrastructure mix’ was based on the water supply and wastewater infrastructure in operation at the Gold Coast during 2007/08. This ‘Traditional’ scenario is summarised in Figure 1 and included the following:

A ‘Future infrastructure mix’ was also defined, incorporating four alternative approaches to urban water supply in addition to the existing ‘Traditional’ infrastructure. The ‘Future’ scenario is summarised in Figure 2. The additional infrastructure included for the ‘Future’ scenario was:

• Dam-sourced mains water supply via two conventional Water Treatment

• The newly-constructed Tugun seawater desalination plant.

Dam

WTP sludge to sewer

SWRO Desalination plant

WTP

existing urban HH

Nonresidential

tank

new HH laundry toilet

Biosolids to farms

STP STP

AWTP

Product water to Dam

new HH laundry toilet

outdoor use

tank

Class B irrigation

existing periurban HH outdoor use

Pimpama STP

Figure 2. ‘Future’ scenario urban water system.

58 DECEMBER 2011 water

Ocean

• A limited number of households (about 6% of total) being provided with Class A+ reticulated water for toilet and external uses, along with a 5000L rainwater tank to supply laundry demands. This encapsulated the newly constructed PimpamaCoomera Waterfuture scheme.

• All other (non-Pimpama) new households serviced by new sewage and STP infrastructure equivalent to the conventional STP infrastructure of the ‘Traditional’ scenario.

tank

methodology Scenario definition

non-residential Class A+ reuse

Ocean

• An indirect potable reuse (IPR) scheme delivering recycled water to the local water supply dam. This envisaged a hypothetical IPR scheme for the Gold Coast region similar to the Western Corridor scheme. The required Advanced Water Treatment Plant (AWTP) was assumed to be located at the largest sewage treatment plant (STP) in the Gold Coast region (Coombabah). Recycled water would be pumped to the local Hinze Dam.

• All other (non-Pimpama) new households having a 5000L rainwater tank to supply toilet, laundry and external uses. This brought the overall coverage of households with rain tanks to 67% of total.

ROC

Pimpama RWP ROC

550,235

222,000

Water Supply – Total (ML/d)

outdoor use

202,000

Total Households

periurban HH

Future

Peri-urban Households

Water Use2 – Total (ML/d)

Nonresidential

Traditional

Ocean

The scenarios were based on assumptions of average household water use generated from Gold Coast data for 2007/08. While high-level water restrictions were in place in the region

technical features

water resources at that time, due to the prevailing drought, there has been only a small rebound in domestic water use since restrictions were eased more recently (Beal et al. 2011). A consistent set of water demand assumptions were used for both the ‘Traditional’ and ‘Future’ scenarios so as to focus specifically on the implications of different infrastructure options.

The ‘Future infrastructure mix’ scenario involved a substantial increase in total water supply capacity. The number of households serviced by this scenario was commensurately increased so as to maintain a water supply-demand balance. For households serviced only with mains water, residential water use was set at 415L/hh/d. For households with additional supplies from rainwater tanks or Class

A+ water, residential water use was assumed to increase to 454L/hh/ds due to more outdoor use, based on evidence from Willis et al. 2009 at the time. Nonresidential water use estimates (from 2007/8) were pro-rated on the projected number of future urban households. Table 1 summarises the water balance for the two scenarios under consideration,

Table 2. Operational inventory summary for Gold Coast centralised urban water system components forming the basis of this study. Feed or Product Operational Inventory Item

Feed or Product

Total Power Use

Total Chemical Use

Flow (ML/d)

Mass (kg/d)

Electricity (kWh/d)

Mass (kg/d as Product)

15,563

Raw Water Pumping

Feed

137.7

WTP

Product Water

136.6

6,880

27,191

3300

Sludge Product (Dry Solids) Mains Water Distribution

Product Water

136.6

13,772

Sewer Collection System

Raw Sewage Product

108.3

42,269

Traditional STPs (4 no.)

Raw Sewage Feed

108.3

75,543

4,914

-1,925

Sec. Effluent Product to Ocean

87.1

25,263

869

Sec. Effluent Product to Irrigation

21.2

incl.

- Dry

29,725

- Wet

263,960

2,951

Raw Sewage Feed

17.3

6,672

Sec. Effluent Product to AWTP

17.3

17,499

4,132

Class A+ Recycled Water Product

17.1

2,244

4,330

- To Houses

3.9

incl.

- To Non-residential uses

3.3

incl.

- To Ocean

9.9

incl.

Electricity Credit (Generated)

Biosolids Product

Screenings & Grit Product - Wet Pimpama STP-AWTP

Biosolids Product - Dry

6,253

- Wet

41,832

Screenings & Grit Product - Wet Hypothetical AWTP for IPR

604

Secondary Effluent Feed

54.0

9,513

Recycled Water Production

44.4

42,209

21,047

- Pumping to Dam

44.4

2,544

RO Concentrate Product to Ocean

8.73

28,391

Chemical Sludge Product

Tugun Desalination Plant

- Dry Solids

5,084

- Wet Solids

25,418

Feed

298

39,634

Product Water

125

432,994

21,403

RO Concentrate Product to Ocean

173

incl.

13,700

Sludge Product (Dry Solids)

water

DECEMBER 2011 59

water resources showing the contribution made by each different urban water supply source.

Inventory Generation Data was collected and/or modelled for the construction and use of the infrastructure items included in each scenario. Construction inventories were extrapolated from other studies where local data was not readily available, and were annualised based on estimates of equipment lifespan. Modelling of the operations phase captured all key operational inputs (e.g. chemicals and power) and outputs (e.g. disposal or reuse of wastewater and biosolids). Wherever possible these were based on actual operating data, with extrapolation from other studies or expert opinion to a limited extent. Inventories were generated for one year of operation of the infrastructure mix for each scenario. Due to space restrictions here, uncertainty estimation in the LCA model inputs and outputs are not considered in this paper but have been discussed elsewhere (Lane et al., 2011). Table 2 contains a summary of the operational inventory for the main centralised components underpinning the urban water cycle scenarios considered in this study. More detailed inventory information is provided by Lane et al. (2011).

Rainwater tanks were assumed to yield on average 84 to 171L/d per tank, based on modelling using TANK software (Vieritz et al. 2007), depending on tank water household uses (external or internal use). Average total power consumption by rainwater tank pumps was assumed to vary from 0.8 to 1.4 kWh/kL pumped depending on the end use and pump control configuration. This is similar to the range reported by Retamal et al. (2009) and Talebpour et al. (2011).

Metals Depletion was included where relevant, mainly because of metals resource use in construction inventories, including pipelines. Despite the relevance of urban water systems to the global phosphorus balance, phosphorus resources are poorly represented in the available LCA impact models, and this currently represents a limitation.

Data for second order inventories (e.g. chemicals manufacture) were taken from available life cycle inventory databases available using the SimaproTM LCA software platform (PRé Consultants, The Netherlands). Australian database inventories were used as far as possible.

The key sources of environmental impact were mapped, so as to identify the major contributors and most significant points of uncertainty;

The environmental tradeoffs involved in shifting towards the ‘Future’ infrastructure mix were considered; and

A direct comparison was made across the alternative water supply options that are being considered for use in SEQ.

Impact Assessment The chosen set of impact categories was based on the latest international developments in LCA impact modelling, modified for relevance to this study. Each so-called ‘mid-point’ indicator implies the potential for environmental impact, rather than attempting to predict actual environmental damage. Included were: Freshwater Extraction; Aquatic Eutrophication Potential; Ecotoxicity Potential (Marine, Freshwater & Terrestrial); Global Warming Potential; Ozone Depletion Potential; Fossil Fuel Depletion; and Human Toxicity Potential.

Analysis was undertaken in three stages:

results environmental impacts of the urban water system The results for the ‘Traditional’ and ‘Future’ scenarios are summarised in Table 3 and Table 4 respectively. As expected, dam water use for the Gold Coast region was the dominant contributor to the Freshwater Extraction

Table 3. Results by LCA midpoint impact category for the ‘Traditional’ infrastructure mix scenario. Freshwater Extraction

Aquatic Eutrophication Potential

Marine Ecotoxicity Potential

Freshwater Ecotoxicity Potential

Terrestrial Ecotoxicity Potential

Global Warming Potential

Ozone Depletion Potential

Fossil Fuel Depletion

Metals Depletion

Human Toxicity Potential

Total Units

GL/y

t PO4-e/y

t 1,4DB-e/y

kt CO2-e/y

kg CFC11-e/y

kt oil-e/y

kt Fe-e/y

kt 1,4DB-e/y

Total Result

51.7

465.7

95.7

7.5

46.0

120.7

753.5

21.1

1.0

3.8

Total Per GL Total Water Supply

1.01 GL

9.11 t PO4-e

1.87 t 1,4DB-e

0.15 t 1,4DB-e

0.90 t 1,4DB-e

2.36 kt CO2-e

14.7 kg CFC11-e

412 t oil-e

20 t Fe-e

74 t 1,4DB-e

Mains Water Supply (Operations)

104.1%

0.7%

6.6%

9.5%

0.8%

22.5%

0.6%

22.3%

3.2%

6.2%

Sewers (Operations)

0.1%

0.6%

0.8%

0.3%

0.1%

16.2%

0.3%

16.9%

0.5%

4.0%

WW Treat & Discharge (Operations)

0.1%

98.8%

80.3%

67.3%

93.8%

47.4%

98.6%

40.3%

1.5%

19.1%

WW Recycling (Operations)

-4.9%

-0.5%

0.1%

7.0%

3.6%

0.9%

0.2%

1.2%

0.0%

0.5%

Rainwater Tanks (Operations)

0.0%

0.1%

0.0%

1.1%

0.0%

1.5%

0.0%

0.4%

Mains Water Supply (Construction)

0.4%

0.3%

9.3%

5.8%

1.1%

8.3%

0.2%

10.3%

6.0%

48.3%

Sewers (Construction)

0.2%

0.1%

1.0%

1.9%

0.2%

1.9%

0.1%

3.9%

1.2%

2.8%

WW Treat & Discharge (Construction)

0.0%

1.4%

7.5%

0.2%

0.9%

0.0%

1.5%

87.4%

1.7%

WW Recycling (Construction)

0.0%

0.3%

0.6%

0.1%

0.6%

0.0%

1.2%

0.1%

16.9%

Rainwater Tanks (Construction)

0.0%

0.3%

0.1%

0.0%

0.3%

0.0%

0.9%

0.0%

0.1%

60 DECEMBER 2011 water

technical features

water resources (FWE) results, with ‘virtual’ water use from infrastructure construction or power generation being negligible. The benefit of lower FWE attributed to the existing Class B reuse system was only small. Since sewage nutrient loads are directed to STPs, the combined operations of the STPs was the major source (98%) of Aquatic Eutrophication Potential (Table 3). Most of this (82%) was the nutrient load in STP effluent discharged to the ocean. Conservatively, nutrient losses from biosolids application (to farms) could potentially account for up to 20% of the total nutrient flux to receiving waters with other indirect pathways (e.g. NOx emissions from power stations) similarly accounting for 2–3%. Reduced fertiliser use only partially offset the nutrient contribution to eutrophication potential from biosolids (-5%), as it was conservatively assumed that a relatively small portion of the biosolids nutrients were available for uptake by crops. This highlights that nutrient recycling via agricultural use of biosolids to achieve effective fertiliser offsets is a key life-cycle consideration. Future studies should give more careful consideration to crop uptake and the potential losses from land-applied nutrients, as these aspects have considerable uncertainty for quantitative analysis.

Wastewater and biosolids flows accounted for the majority of the ecotoxicity results (Table 3). Biosolids metals loadings to agricultural soils contributed 93% of the Terrestrial Ecotoxicity Potential (TEP), and 67% of the Freshwater Ecotoxicity Potential (FEP), assuming a portion of the metals is transferred to adjacent streams over the long term. Effluent discharges to the sea contributed most (56%) of the Marine Ecotoxicity Potential (MEP), principally due to residual chlorine (40%) and metals (14%, mainly manganese) in ‘Traditional’ STP secondary effluents. Organic micropollutants in the various wastewater streams made relatively small contributions to the ecotoxicity results (<1% to 4%). These findings are subject to important data limitations and methodological concerns associated with the toxicity modelling for the three contaminant groups (chlorine, metals & organics). Substantial indirect sources of MEP (42%) were also noted, particularly associated with transport fuel use (at least 23% of total MEP due to impacts, for example, from offshore fossil fuel rigs). Trucking of biosolids was the major transport inventory across the full life cycle of the urban water system, with the long distance transport of water and wastewater treatment chemicals being smaller but notable nevertheless (5%

of total MEP in the ‘Traditional’ and 7% in the ‘Future’ scenario). Chemicals manufacture made a significant (10%) contribution to the FEP in the ‘Traditional’ scenario, with a large number of other indirect pathways collectively contributing a further 16% of total FEP. In the ‘Future infrastructure mix’ (Table 4), increased use of chemicals (at the wastewater recycling and desalination plants) resulted in relatively increased impacts due to manufacture (17% of total FEP), with the responsibility for the relative increase in chemicals use spread across the wastewater recycling and the desalination plants. Power generation is a significant contributor (17%) of total Human Toxicity Potential (HTP) for the ‘Traditional’ scenario and increasing (to 27%) in the ‘Future infrastructure mix’ scenario. In contrast to the ecotoxicity results, the available models suggested that manufacture of construction materials is the major source of HTP (38 to 48% of total – refer to Table 3 and Table 4). Limitations with the available toxicity models prevented a more thorough assessment of the HTP associated with important aspects of the water system operations (e.g. WTP disinfection byproducts; and mixing of recycled water into mains supply dams). This aspect

Table 4: Results by LCA midpoint impact category for the ‘Future’ infrastructure mix scenario. Freshwater Extraction

Aquatic Eutrophication Potential

Marine Ecotoxicity Potential

Freshwater Ecotoxicity Potential

Terrestrial Ecotoxicity Potential

Global Warming Potential

Ozone Depletion Potential

Fossil Fuel Depletion

Metals Depletion

Human Toxicity Potential

Reporting Total Units

GL/y

t PO4-e/y

t 1,4DB-e/y

kt CO2-e/y

kg CFC11-e/y

kt oil-e/y

kt Fe-e/y

kt 1,4DB-e/y

Total Result

53.0

1012.5

258.9

23.8

127.0

519.1

2081.7

108.7

2.9

14.2

Total per GL Total Water Supply

0.39 GL

7.36 t PO4-e

1.88 t 1,4DB-e

0.17 t 1,4DB-e

0.92 t 1,4DB-e

3.77 kt CO2-e

15.13 kg CFC11-e

790 t oil-e

21 t Fe-e

103 t 1,4DB-e

Mains Water Supply (Operations)

102.4%

3.4%

10.0%

11.8%

1.0%

39.4%

1.6%

43.8%

6.7%

15.1%

Sewers (Operations)

0.2%

0.7%

0.8%

0.2%

0.1%

10.1%

0.3%

8.8%

0.4%

2.9%

WW Treat & Discharge (Operations)

0.3%

91.0%

63.5%

58.0%

92.6%

29.4%

96.8%

20.6%

1.4%

13.2%

WW Recycling (Operations)

-4.6%

3.8%

15.3%

16.2%

4.6%

8.2%

0.8%

9.3%

1.3%

4.4%

Rainwater Tanks (Operations)

0.1%

0.5%

0.7%

0.2%

0.1%

5.9%

0.2%

6.9%

0.4%

2.2%

Mains Water Supply (Construction)

0.9%

0.3%

5.5%

4.0%

0.9%

3.8%

0.2%

4.5%

2.9%

38.4%

Sewers (Construction)

0.6%

0.1%

1.0%

1.6%

0.2%

1.2%

0.1%

2.1%

1.2%

2.1%

WW Treat & Discharge (Construction)

0.0%

1.4%

6.5%

0.2%

0.6%

0.0%

0.8%

85.1%

1.3%

WW Recycling (Construction)

0.2%

0.1%

0.6%

1.0%

0.2%

0.7%

0.0%

1.2%

0.6%

20.1%

Rainwater Tanks (Construction)

0.0%

0.1%

1.4%

0.4%

0.1%

0.7%

0.0%

2.1%

0.0%

0.4%

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DECEMBER 2011 61

water resources requires further research to extend the impact models within LCA software. Power use contributes 52% and 72% of the Global Warming Potential (GWP) for the ‘Traditional’ and ‘Future’ scenarios respectively. The increase reflects the energy-intensive water supply options included in the latter, particularly from the seawater desalination plant. Despite this, wastewater treatment sector operations make the biggest contribution (39%) to GWP in the ‘Future infrastructure mix’. While sewage treatment power use at the Gold Coast is typical of other STPs across SEQ, it was nearly doubled by the high energy pumping requirements for sewage collection and final wastewater disposal at the Gold Coast. Power use was also the major cause of Fossil Fuel Depletion across the water system life cycle. Fugitive emissions from STPs contributed 15% and 9% respectively to GWP of the ‘Traditional’ and ‘Future’ scenarios respectively. This was based on estimates of dissolved methane generated in sewers; methane or nitrous oxide from biosolids and denitrification processes; and carbon dioxide of nonbiogenic origin. Methane emitted from dam sediments further contributed to GWP (7% of the ‘Traditional’ and 2% of the ‘Future’ scenario). However, these contributions are subject to considerable uncertainties due to variability of the underlying biological and physical mechanisms.

Summary for the ‘traditional’ vs. ‘future’ Scenarios The adoption of non-traditional water supply technologies for the ‘Future infrastructure mix’ meant this scenario had a lower specific impact (per GL total water supply) for FWE and AEP (Table 3 and Table 4). This is a direct result of the key legislative drivers to address the environmental challenges that have traditionally been the dominant priority for urban water regulators and managers (eg, managing environmental flows; and higher effluent discharge standards with advanced nutrient removal for new or upgraded STPs and AWTPs associated with water recycling). The downside of advanced wastewater treatment, water recycling and desalination was significant increases on a specific basis (per GL total water supply) basis, particularly for GWP and FFD, and to some extent for FEP and HTP associated with the ‘Future’ urban water system (Table 3 and Table 4). Predictably, this is largely due to the power and chemicals intensity associated with the new water supply systems. MEP, TEP

62 DECEMBER 2011 water

and ODP were not significantly different in the two scenarios on a specific basis (per GL total water supply), implying that the change in technology for the ‘Future infrastructure mix’ does not greatly influence these impact potentials. Aside from the change in technology for the ‘Future’ infrastructure mix and freshwater extraction considerations, large increases in the absolute values of impact potentials were caused by the population growth associated with the ‘Future’ scenario (Table 3 and Table 4). While the results of this study are subject to data and methodological uncertainties, they do focus attention on those parameters that are likely to be the most important from a broader social and environmental perspective. It suggests that future pressures for impact mitigation by the urban water sector are likely to be spread across a wider range of issues than has traditionally been the case. It also confirms that greenhouse gas emissions cannot be considered an adequate proxy for the range of important environmental externalities associated with building and operating urban water systems.

Comparison of the new Water Supply Options For the four alternative water supply options of the ‘Future infrastructure mix’, the environmental implications of each were directly compared with the ‘Traditional’ (dam supply) option so as to provide a more generic evaluation of the tradeoffs involved in a choice between them. The results are shown in Table 5 on a specific basis (per GL mains water supplied). Obviously the main benefit of the alternative water supply options is a major reduction in Freshwater Extraction (FWE), compared with traditional dam supplies. The small FWE requirements for the alternatives are largely attributable to water used for generation of additional power associated with these options. Rain tanks and desalination have the potential to slightly increase Aquatic Eutrophication Potential (AEP), mainly due to indirect pathways (e.g. NOx emissions from power stations due to increased power use). Conversely, the water recycling options (Class A+ and IPR) have the benefit of a net reduction in AEP for the overall system. The advanced treatment required to achieve a higher water quality for recycling brings with it greater nutrient removal for reasons of either safeguarding fouling of membrane processes in the treatment

train, or ‘tighter’ environmental standards associated with the discharge of reject streams. In this study, the Class A+ reuse system achieved a smaller AEP benefit (per GL of water supplied) than the IPR alternative, due to the Class A+ AWTP sourcing water from the Pimpama STP upstream, which achieved more advanced nutrient (N & P) removal than the Coombabah STP. The latter was assumed to supply the hypothetical IPR scheme. The AWTP for the IPR scheme was based on data from the Bundamba (Western Corridor) plant, which incorporates advanced nutrient removal (via chemical treatment, reverse osmosis and treatment of RO concentrate before environmental discharge). In the case of the Pimpama-Coomera scheme, operational constraints mean that the Pimpama AWTP must process 100% of the secondary effluent regardless of the overall demand for Class A+ water. Given the relatively low Class A+ demands adopted, a significant proportion (59%) of Class A+ quality water is discharged to the sea for this alternative water supply in our ‘Future’ scenario. The results in Table 5 suggest that, for two key reasons, this will limit the benefits and magnify the downsides of the Class A+ recycling approach. Firstly, because the majority of the power and chemicals use is associated with the AWTP treatment steps, the associated impacts are largely incurred regardless of the savings in mains water use. Secondly, the high residual chlorine concentrations in the Class A+ product water discharged to the sea negates any toxicity benefits from reducing secondary effluent discharge. To explore the ramifications of these design constraints, results were generated for a ‘sidestream’ Class A+ option where the AWTP throughput is matched to the end-use demand. With this configuration, surplus secondary (STP) effluent would be discharged directly to the sea. Table 5 shows that the negative impacts associated with the AWTP treatment steps (power, chemicals and other materials) are reduced substantially. Avoiding the marine discharge of highly chlorinated effluent also means that a net Marine Ecotoxicity Potential (MEP) benefit is achieved. The only downside is the reduced AEP benefit because of the lower overall level of nutrient removal that is achieved. The Class A+ (sidestream) and IPR systems delivered substantial net reductions in MEP as a result of the removal of dissolved micropollutants (including metals) through advanced

technical features

water resources treatment (Table 5). However, since all micropollutants are not completely removed, a portion of the toxicity potential burden is shifted to freshwater ecosystems instead of discharge to the sea. The Terrestrial Ecotoxicity Potential (TEP) and Freshwater Ecotoxicity Potential (FEP) impacts for Class A+ and IPR were small but noticeable (Table 5), caused by a combination of redirecting key pollutants to land application via recycled water and biosolids reuse/ disposal. The most noticeable changes across the options were in Global Warming Potential (GWP) and Fossil Fuel Depletion (FFD). Of the options considered, the ‘sidestream’ Class A+ system had the lowest GWP and FFD (Table 5), followed by the ‘Traditional’ dam supply option. The exact relativities here will be highly dependent on the catchment characteristics and supply system power requirements. Power use (and to some extent chemicals use), was the main cause of GWP and FFD in all cases, including the significant increases associated with rain tanks, water recycling and desalination (Table 5). Analysis using default assumptions showed that seawater desalination had the highest GWP and FFD of the four scenarios. However, ranking the results for the rainwater tank scenario is made difficult by the substantial uncertainties involved in predicting the long-term energy

traditional water supply technologies in response to growing populations is likely to mean that future pressures for environmental mitigation by the urban water sector will be spread across a wider range of issues than has traditionally been the case. Using LCA, the following conclusions can be drawn from our study:

burden of a large number of rainwater tank installations. Table 5 shows that the tank energy burden could vary from being on par with recycling systems, to greater even than sea water desalination, depending on the combination of supplydemand balance, tank configuration, and pump efficiency. Similarly, methane emitted from sediments, leaf litter etc, was identified as a significant potential source of GWP for the traditional dam supply option. Further details on the sensitivity analysis are provided in Lane et al. (2011).

• Power use is a major point of distinction between the four alternative water supply options considered in this study. Predictably, impacts related to power for the urban water cycle will increase substantially in the future as more energy-intensive water supply technologies are adopted. However, we found that the LCA approach helped to compare alternatives such as rain tanks and water recycling, for which the relativities in power consumption and associated impacts are not necessarily intuitive when planning for urban systems as a whole.

The differences across the options in Ozone Depletion Potential were negligible when considered in the context of the overall impacts associated with the Gold Coast ‘Traditional infrastructure mix’. The differences in Metals Depletion were largely attributable to differences in construction material inventories (e.g. predominantly piping) and to some extent consumption of chemicals (alum or iron salts) for advanced treatment. Human Toxicity Potential was also dominated by the construction material inventories (eg, predominantly piping, particularly some plastic types).

• While power use is known to be the biggest indirect source of greenhouse gas emissions for an urban water system, our study included allowance for direct emissions (principally N2O and/or CH4 from sewers, wastewater treatment and dam storage systems). We found that the LCA approach helped to quantify the relative contribution from such possible fugitive emissions to Global Warming Potential. This, in turn, may be useful in developing greenhouse mitigation strategies.

Conclusions While this study was focussed on Gold Coast infrastructure options, the results and conclusions are largely informative to the debate on the range of wastewater and water supply options being contemplated across SEQ and elsewhere in Australia. The incorporation of non-

Table 5. Comparison of specific LCA impact potentials for alternative urban water supply options. Units of Impact Potential per GL Mains Water Supply

Traditional Dam Supply

Class A+ (PimpamaCoomera)

Class A+ (Sidestream)

IPR (Via Dam)

Raintanks (Low Energy)

Raintanks (High Energy)

SWRO Desalination

1.067

0.004

0.002

0.008

0.003

0.012

0.010

tonnes PO4-e

0.1

-3.3

-1.6

-15.8

0.2

0.9

0.8

Marine Ecotoxicity Potential

tonnes 1,4DB-e

0.3

6.4

-1.4

-1.2

0.2

0.5

0.4

Freshwater Ecotoxicity Potential

tonnes 1,4DB-e

0.02

0.15

0.09

0.17

0.00

0.01

0.05

Terrestrial Ecotoxicity Potential

tonnes 1,4DB-e

0.02

0.49

0.25

0.03

0.01

0.03

0.02

Global Warming Potential

ktonnes CO2-e

0.725

1.245

0.578

2.395

0.933

5.318

4.415

kg CFC11-e

0.1

0.9

0.4

0.8

0.1

0.8

0.7

Fossil Fuel Depletion

tonne oil-e

135

291

136

584

273

1,369

1,078

Metals Depletion

tonne Fe-e

1.9

4.0

3.8

3.7

0.3

1.7

4.3

tonnes 1,4DB-e

Water Supply Option:

Impact Category Freshwater Extraction Eutrophication Potential

Ozone Depletion Potential

Human Toxicity Potential

water

DECEMBER 2011 63

water resources • The significance of a number of environmental issues identified in this study demonstrates that greenhouse gas emissions are not an adequate proxy for the range of important environmental externalities associated with urban water system operations. • LCA provides a number of impact models that may enhance a broadspectrum environmental analysis of urban water systems. A number of areas were identified where current LCA methodology for urban water systems analysis could be improved. Notably, LCA models should be extended to consider the significance of phosphorus recovery in the context of global minerals resource depletion challenges. • Similarly, regarding nutrient balances for any land application of biosolids and wastewater, existing LCA models suggest a potential for significant nutrient transfers to adjacent waterways. The likelihood and implications of achieving lower artificial fertiliser use also need to be considered. Quantifying fertiliser offsets and nutrient fluxes is subject to large uncertainties, and LCA in this area would be enhanced by guidance on best practice approaches to doing so in a regional context. • Other than Human Toxicity Potential, the impacts considered in this study associated with infrastructure construction are likely to be of secondary concern. This applied even for the relatively materialsintensive rainwater tank and ‘third pipe’ water recycling reticulation systems. • Wastewater treatment operations are the biggest source of most of the impacts considered, and may offer the greatest potential for reducing the overall environmental burden of the urban water system. Therefore, debates on the environmental implications of urban water system planning decisions need to have a wider focus than just the choice between water supply alternatives. • Wastewater and biosolids pollutants (chlorine, metals and organics) are the major source of potential ecotoxicity across the infrastructure lifecycle. Discerning the relative importance of these different contaminants is constrained by limitations with the available contaminant data, and the available LCA toxicity models. In this regard, further discussion of the LCA ecotoxicity models applied can be found in the full report from this study (Lane et al., 2011).

64 DECEMBER 2011 water

• One of the benefits of the using the LCA approach is that indirect contributions to impact potentials can be tracked. Examples are transport (e.g. fuel use for biosolids and chemicals), mining and manufacturing (e.g. for treatment chemicals), which are responsible for substantial indirect contributions to the overall ecotoxicity potential associated with an urban water system. • Where direct water recycling systems (i.e. ‘third pipe’ or similar) and household scale rainwater tanks are under consideration, quantitative comparisons of urban water supply alternatives (such as by LCA) should include sensitivity testing for different end-use demand levels and system configurations. The results in our study suggest that assumptions on the supply-demand balance for these systems could be critical to their ranking in comparative assessment of different water supply options.

Acknowledgements This paper is a condensed version summarising the outcomes of a research project funded by the Urban Water Security Research Alliance (UWSRA) in Queensland. The final report is available through UWSRA. For more information visit the website at: www. urbanwateralliance.org.au/. This paper is published with the permission of the Director of UWSRA. Assistance with data collection and review from a number of individuals, particularly those within the former Gold Coast Water (now Allconnex Water, Southern Region) and SEQWater (Water Secure), is gratefully acknowledged.

the Authors

Dr David de Haas (email: david. dehaas@ghd.com) is an engineering technologist with GHD Pty Ltd (Brisbane) and also worked part-time as a researcher at the Advanced Water Management Centre, University of Queensland for the duration of this project. Joe Lane is an engineer and PhD Candidate at the Advanced Water Management Centre, University of Queensland. Paul Lant is Professor and Head of School, Chemical Engineering, at the University of Queensland.

references Beal C, Stewart RA, Huang T & Rey E, 2011: SEQ Residential End Use Study. Water Journal 38 (1), pp 92–96. Friedrich E, Pillay S & Buckley CA, 2009: Carbon footprint analysis for increasing water supply and sanitation in South Africa: a case study. Journal of Cleaner Production 17, pp 1–12. Gallego A, Hospido A, Moreira MT & Feijoo G, 2008: Environmental Performance Of Wastewater Treatment Plants For Small Populations. Resources, Conservation and Recycling 52, p 931. Gaterell MR, Griffin P & Lester, JN, 2005: Evaluation of Environmental Burdens Associated with Sewage Treatment Processes Using Life Cycle Assessment Techniques. Environmental Technology 26, pp 231–249. Lane J, de Haas D & Lant P, 2011: Life Cycle Assessment of the Gold Coast Urban Water System. Technical Report to the Urban Water Security Research Alliance, submitted September 2011. Lundie S, Peters G & Beavis P, 2004: Life Cycle Assessment for Sustainable Metropolitan Systems Planning. Environmental Science and Technology 38, pp 3465–3473. Lundie S, Peters G and Beavis P, 2005: Quantitative systems analysis as a strategic planning approach for metropolitan water service providers. Water Science & Technology 52(9), pp 11–20. Mrayed S & Leslie G, 2009: Examination of greenhouse footprint for both desalination and water recycling processes. Proceedings of Ozwater’09 Conference, Australian Water Association, Melbourne, 16–18 March 2009. Munoz I & Fernandez-Alba AR, 2008: Reducing the environmental impacts of reverse osmosis desalination by using brackish groundwater resources. Water Research 42, pp 801–811. Raluy RG, Serra L, Uche J & Valero A, 2005: Life Cycle Assessment of Water Production Technologies. Part 2: Reverse Osmosis Desalination versus the Ebro River Water Transfer. International Journal of Life Cycle Assessment 10(5), pp 346–354. Retamal M, Glassmire J, Abeysuriya K, Turner A & White S, 2009: Investigation into the energy implications of household rainwater systems. Final Report – CSIRO. Institute for Sustainable Futures, UTS, Sydney. Talebour MR, Stewart RA, Beal C, Dowling B, Sharma A & Fane S, 2011: Rainwater Tank End Usage and Energy Demand: A pilot study. Water Journal 38(1), pp 85–89. Vieritz A, Gardner T & Baisden J, 2007: Rainwater TANK Model Designed for Use by Urban Planners. AWA Ozwater’07 Conference, 4–8 March 2007, Sydney. Willis R, Stewart RA & Emmonds S, 2009: Pimpama-Coomera dual reticulation end use study: baseline situational context and post commission end use prediction. Paper presented at Reuse09 Conference, 20–25 September 2009, Brisbane.

technical features

water treatment

refereed paper

EFFECTIvE WATER QuALITy MonIToRIng FoR DRInKIng WATER TREATMEnT PLAnTS R Fabris, K Braun, J Morran, L Ho, D Cook, M Drikas Abstract The increasing regulation of undesirable by-products formed as a result of water treatment and disinfection has raised awareness of the need for monitoring dissolved organic carbon (DOC). Operationally, however, there is still a reliance on traditional water quality parameters such as turbidity and colour, the usefulness of which can be limited. Alternative parameters are required that are more capable of representing plant performance without adding unnecessary complexity to water quality monitoring. UV absorbance is one such parameter. The suitability of monitoring absorbance at 254nm as a surrogate for dissolved organic carbon is discussed in this paper, using long-term monitoring at a pilot treatment facility using four different treatment technologies in realistic combinations.

Introduction Water treatment plants have traditionally been managed with aesthetic parameters as the indicators of operational performance; however, with the greater understanding of the effects of waterborne chemicals on human health, the emphasis has shifted to include undesirable contaminants present in the source water and those formed through treatment and disinfection processes. Of all source water contaminants, natural organic matter (NOM) is the most common and is usually present in the highest concentration. In fact, NOM is responsible for the majority of the coagulant demand in conventional treatment systems, and the resultant DOC remaining represents the majority of the disinfectant demand in most chlorinated systems. For this reason, the importance of monitoring NOM removal in modern drinking water treatment cannot be understated. In drinking water treatment, there is benefit to NOM monitoring for many different facets of the treatment process. For estimation of coagulant demand in a source water, or treatment efficiency (DOC removal), a measure of NOM

concentration is required (Chow et al., 2006). Describing a change in disinfection demand in treated water also benefits from NOM measurement. Of the available parameters, DOC analysis is the most easily and directly linked with treatment and disinfection performance, but it can be difficult and expensive to monitor routinely. Accurate determination of DOC requires a high degree of technical skill, maintenance and quality control, as results are easily influenced by the operator and operational conditions (Kaplan, 2000). In field monitoring, it is often practical to use a surrogate parameter that is more easily determined, reproducible and independent of operator variability. UV absorbance measurement is simple, non-destructive and requires no reagent addition, so it is easily applied and, like turbidity and colour, is suitable for online monitoring. Although accurate measurement of UV absorbance requires pre-filtration to eliminate the light-scattering effects from turbidity, instruments exist on the market enabling online spectral ‘correction’ for turbidity effects, negating the need for filtration (Langergraber et al., 2004). Absorbance of light by NOM can occur within a wavelength range of 220 to 280nm, representing a variety of organic matter character, with the intensity of response generally reducing with increasing wavelength (Del Vecchio and Blough, 2004; Hur et al., 2006; Maitilainen et al., 2011). UV absorbance at 254nm has long been used as a measure of aromatic organic matter which can be linked to treatability through coagulation mechanisms as well as reactivity with chlorine disinfectants (Korshin et al., 1999; Deflandre and Gagné, 2001; Chen et al., 2002). In this paper, the usefulness of traditional water quality parameters such as colour are discussed, along with UV absorbance at 254nm and DOC analysis in the context of long-term water quality data from four treatment processes incorporating advanced treatments for improved DOC removal from common source water.

Material and Methods The source water for the investigation was from the inlet to the Mt Pleasant water treatment plant (WTP) in South Australia. This water is sourced from the Murray River via the 60km Mannum to Adelaide pipeline that provides the major drinking water supply for metropolitan Adelaide. Due to variable residence time in transit, inlet water quality at Mt Pleasant WTP may often be different from the river water quality entering at Mannum, providing a variety of seasonal challenges to drinking water treatment. Details of the process streams are described below:

Stream 1 – Conventional Treatment The conventional treatment comprised coagulation/flocculation/dual media filtration utilising an upflow clarifier and gravity-fed filter column. The coagulant employed was aluminium sulphate (alum) as Al2(SO4)3.18H2O. Coagulation pH of between 6.0 and 6.5 was maintained through addition of caustic (sodium hydroxide) or sodium bicarbonate buffering, depending on source water alkalinity. In addition, a coagulant aid, either anionic polyacrylamide (LT20, Ciba Specialty Chemicals, Australia) or high molecular weight poly-DADMAC (LT425, Ciba, Australia) was also dosed downstream of the coagulant. This process was selected as a baseline/ control as it represents the most widely applied drinking water treatment process employed in Australia.

Stream 2 – MIEX/Conventional Coagulation Treatment comprised magnetic ionexchange contact (MIEX DOC® process, Orica, Australia) for DOC removal coupled with coagulation/flocculation/dual media (sand/anthracite) filtration. Although the coagulation stage may remove additional DOC, the dosing strategy targets clarification (turbidity removal), a function that ion-exchange cannot achieve alone. The primary coagulant used is aluminium sulphate (alum) as Al2(SO4)3.18H2O; however, additional coagulant aids, LT22

water

DECEMBER 2011 65

water treatment

The third treatment stream was comprised of the product water from Stream 2 with the addition of two parallel granular activated carbon (GAC) filters utilising Filtrasorb 400 GAC (Calgon Carbon Corporation, USA). F400 is a bituminous coal-based GAC with effective granule size 0.550.75mm, which is commonly applied in water and wastewater applications for organic contaminant removal. Filtration was achieved using packed bed columns with gravity-fed empty bed contact times (EBCT) of approximately 14 minutes at 125L/hr per column. The filtrate from both columns was blended into a common storage prior to analysis.

Stream 4 – Microﬁltration/ nanoﬁltration Dual membrane filtration consisted of microfiltration (MF) pre-treatment for particulate removal using a single submerged hollow fibre module (Memcor CMF-S system, US), followed by a single FILMTEC NF 270-4040 spiral-wound nanofiltration (NF) membrane (DOW Chemical Company, US). The microfiltration system was fed with 1000L/ hr and operated at 75% permeate recovery. The nanofiltration system operated in cross-flow configuration at 50% recovery, producing 325L/hr. Nominal pore size for the microfiltration is reported as 0.2µm, with the molecular weight cut-off for the NF being 270 Daltons, achieving high levels of DOC removal with significant reduction in hardness.

Analyses Grab samples for dissolved organic carbon (DOC) and UV absorbance at 254nm (UV254) analyses were filtered 300

Turbidity (NTU)

250 200

Results and Discussion This paper is based on two years of water quality data for four treatment processes treating the same source water between July 2009 and June 2011. Within that time, significant water quality changes were experienced, largely as a result of two major events. Following a period of extended drought where river inflows were minimal and source water quality was relatively stable, turbidity spikes in the influent signified the beginnings of two subsequent and different water quality periods, the Mannum-Adelaide Pipeline (MAP) flush and the arrival of floodwaters from Eastern Australia denoted as ‘MAP Flush’ and ‘Flood Inflows’ respectively. Data for turbidity and colour is presented in Figure 1, with assigned water quality periods indicated. A clear disparity in the trends of the two parameters is evident between the water quality periods, with the MAP flush producing high

Mt.Pleasant WTP Source Water Turbidity & Colour

Turbidity Colour

150

100

1-Jul-09 1-Oct -09 1-Jan -10 3-Apr-10 4-Jul-10 4-Oct -10 4-Jan -11 6-Apr-11 7-Jul-11

Figure 1. Raw water turbidity (NTU) and colour (HU) at Mt Pleasant WTP, July 2009 to June 2011. MAP = Mannum-Adelaide pipeline.

66 DECEMBER 2011 water

The colour reduction for the four treatment streams is shown in Figure 2. Despite variation in raw water colour between 6HU in the stable period to peaks of 107HU within the flood inflows, colour reduction was consistently high, especially for the advanced multi-stage processes (MIEX/Coag/GAC and MF/ NF), which averaged greater than 98% reduction over the two years. As a consequence of the consistently high removals, monitoring of treated water colour yielded limited information on the performance of these processes. For the traditional coagulation treatment stream, the colour data retained sufficient resolution to describe the treatment performance variation. Some difficulty was encountered in maintaining optimum coagulation conditions throughout the changing water quality periods, especially when rapid changes occurred. This was in part due to the reactive nature of coagulation control where decline of treated water quality dictated the operational changes. Within several challenge periods, additional chemicals were dosed to maintain target pH and floc settleability for acceptable filter run times, but only after water quality showed deterioration, leading to the largest span between maximum and minimum reduction percentages of all the treatments.

Colour reduction - July 2009 to June 2011

125 100

turbidity but relatively low colour water. However, with the arrival of the flood waters, the impact of colour was markedly increased. Following the initial spike in the flood inflow period the turbidity diminished rapidly, several months before the decline of raw water colour. Although these are the two most commonly analysed quantitative (turbidity) and qualitative (colour) parameters in drinking water treatment, their relationship to the quality of the water in terms of treatability and disinfection efficiency is limited.

100%

% reduced

Stream 3 – MIEX/Conventional Coagulation/gAC

through 0.45 µm pre-rinsed membranes. Colour was measured after further filtration through 0.22 µm pre-rinsed membranes to negate the light-scattering effect of ultrafine silt present in this source water, which artificially elevates colour readings. Analysis was by the method of Bennet and Drikas (1993). UV254 was measured through a 1cm quartz cell and colour through a 5cm cell using an Evolution 60 Spectrophotometer (Thermo Scientific, USA). DOC was measured using a Sievers 900 Total Organic Carbon Analyser (GE Analytical Instruments, USA). Turbidity measurements were conducted on a 2100AN Laboratory Turbidimeter (Hach, USA), with results expressed in nephelometric turbidity units (NTU). Total trihalomethanes (THMs), the sum of chloroform, dichlorobromomethane, chloro-dibromomethane and bromoform, was analysed by headspace gas chromatography with electron capture detection.

Colour (HU)

and LT425 (Ciba Specialty Chemicals, Australia), were also dosed periodically during coagulation as required.

refereed paper

75% 50% 25% 0%

Average Conv

MIEX/Coag

MIEX/Coag/GAC

MF/NF

Figure 2. Average, maximum and minimum colour reduced by each treatment technology. Conv = conventional coagulation; MIEX/Coag = MIEX adsorption and coagulation; MIEX/Coag/GAC = MIEX, coagulation and GAC adsorption; MF/NF = microfiltration and nanofiltration.

technical features

water treatment

refereed paper

Mt.Pleasant WTP Source Water DOC

DOC (mg/L C)

The most relevant parameter to monitor in terms of treatment efficiency is dissolved organic carbon (DOC), which is a quantitative measure that has direct connection to both coagulant and disinfectant demand. Source water DOC (Figure 3) showed rapid increases within short intervals in May and December 2010, consistent with the onset of the new water quality periods, but peaked between February and March 2011 when the highest levels of aquatic organic matter arrived with the flood waters, three months after the turbidity peak that described the beginning of the period. Actual DOC removal was less complete than indicated by colour reduction and clear differences in the performance of the different treatments were apparent (Figure 4).

% removed

In terms of water quality parameters, the absorbance of light is 0 one of the easiest to apply to monitoring practices, as it is non1-Jul-09 1-Oct-09 1-Jan-10 3-Apr-10 4-Jul-10 4-Oct-10 4-Jan-11 6-Apr-11 7-Jul-11 destructive and requires no chemical processing, even offering the Figure 3. Raw water DOC (mg/L C) at Mt Pleasant WTP, July 2009 opportunity for real-time online application. While determination to June 2011. MAP = Mannum-Adelaide pipeline. of colour is also dependent on the absorbance of light, intensity at DOC Removed - July 2009 to June 2011 456nm in the visible light region is of relatively low energy compared 100% to absorbance in the ultraviolet spectrum. UV absorbance at 254nm has long been applied to characterisation of organic matter 75% (Krasner et al., 1996; Korshin et al., 1999) and as a surrogate for the character fractions of DOC that are involved in coagulation 50% mechanisms and ion exchange, as well as the greatest reactivity with disinfectants (Chow et al., 2006, Korshin et al., 2009).

Although the difference between a colour of 1 and 3HU is not able to be visually distinguished and may be dismissed as a simple

Table 1. Comparison of colour and absorbance at 254nm (UV254) as surrogates for dissolved organic carbon (DOC) monitoring using data from July 2009 to June 2011. DOC vs UV254 n

p-value

DOC vs Colour n

Raw

0.68

<0.001

0.85

<0.001

0.92

<0.001

0.65

<0.001

MIEX/Coag

0.93

<0.001

0.24

<0.001

MIEX/Coag/GAC

0.86

<0.001

0.09

0.016

MF/NF

0.01

0.410

0.00

0.574

MIEX/Coag

MIEX/Coag/GAC

MF/NF

Figure 4. Average, maximum and minimum DOC removed by each treatment technology. Conv = conventional coagulation; MIEX/ Coag = MIEX adsorption and coagulation; MIEX/Coag/GAC = MIEX, coagulation and GAC adsorption; MF/NF = microfiltration and nanofiltration. Raw Water UV254

1.00

0.75

0.50

0.25

0.00 1-Jul-09 1-Oct-09 1-Jan-10 3-Apr-10 4-Jul-10 4-Oct-10 4-Jan-11 6-Apr-11 7-Jul-11

Figure 5. Raw water UV absorbance (/cm at 254nm) at Mt Pleasant WTP, July 2009 to June 2011. MAP = Mannum-Adelaide pipeline. UV254 reduction- July 2009 to June 2011

100%

75% 50% 25%

p-value

Conventional

Average Conv

Absorbance at 254nm (/cm)

Comparing colour and absorbance at 254nm as surrogates for DOC removal shows that while acceptable correlations may be obtained for both parameters when values are high, such as in the raw water, when increasing levels of treatment are applied, the relationship of colour to DOC diminishes and becomes unreliable (Table 1). This is especially apparent for MIEX/ Coagulation (Figure 7), MIEX/Coagulation/GAC and MF/NF, as evidenced by lower correlation coefficients (R2) and increasing p-values. The p-value represents the statistical probability that the relationship between the parameters does not exist and is expressed as a number between 0 (certain) and 1 (no relationship).

25%

% reduced

Although UV absorbance at a single wavelength does not present a complete picture of the organic character (Del Vecchio and Blough, 2004), it is more sensitive for the monitoring of treatment effectiveness than more commonly applied water quality parameters like colour. The raw water UV254 data is shown in Figure 5, with reduction by the four treatment processes in Figure 6. As removal of UV-absorbing material is favoured by coagulation and ion-exchange mechanisms, UV254 reduction is generally higher than actual DOC removal but retains the ability to differentiate between the treatments. The broad span of reduction (min. 27% to max. 96%) through the conventional coagulation process is indicative of the high sensitivity of this parameter to treatment effectiveness, giving clear variations between sub-optimal and optimised conditions.

Average Conv

MIEX/Coag

MIEX/Coag/GAC

MF/NF

Figure 6. Average, maximum and minimum absorbance at 254nm (/cm) removed by each treatment technology. Conv = conventional coagulation; MIEX/Coag = MIEX adsorption and coagulation; MIEX/ Coag/GAC = MIEX, coagulation and GAC adsorption; MF/NF = microfiltration and nanofiltration.

water

DECEMBER 2011 67

water treatment

refereed paper

MIEX / Coagulation Treatment Stream

6 5

0.07

DOC

0.06

Colour

0.05

UV254

0.04

0.03

Absorbance at 254nm (/cm)

DOC (mg/L) & Colour (HU)

0.08

low levels are limited, as demonstrated by the minimal THM, averaging 13µg/L after 7-day chlorine contact at 30°C.

One of the major operational issues that arise 2 0.02 from residual 1 0.01 DOC in treated waters is reaction 0 0.00 1-Jul-09 1-Oct-09 1-Jan-10 3-Apr-10 4-Jul-10 4-Oct-10 4-Jan-11 6-Apr-11 7-Jul-11 with disinfection chemicals to Figure 7. Comparison of treated water DOC, colour and UV form undesirable absorbance at 254nm for MIEX/coagulation process water, by-products. A highlighting differences in data resolution. key benefit of measurement error, it may also indicate improved treatment is that the amount the beginnings of treatment failure with and variability of DBP formation due to consequences for downstream water source water quality changes is reduced. quality. More sensitive analyses such as UV This was observed through the four absorbance can still continue to adequately applied treatments with the conventional describe treated water quality within the coagulation stream showing the highest range of modern drinking water treatment DOC and, consequently, THM (Table 2). technologies. In the case of coagulation Advanced multi-stage treatments like the monitoring (Conventional), the ability of MF/NF stream showed consistently low UV254 to relate to DOC removal and, hence, THM formation, regardless of seasonal treatment efficiency is significantly more variation in the source water. accurate than colour (R2 = 0.92 versus 0.65, respectively).

Conclusions

In a practical example, at the onset of the MAP flush period, raw water DOC values increased rapidly, resulting in residual DOC values from the conventional treatment stream increasing from 1.6mg/L to 3.1mg/L over two weeks (16–27 April 2010). As a consequence, chlorine demand increased by 50%, requiring careful control of dosing to maintain disinfection. In this period, colour values increased by just 4 measurement units from 1HU to 5HU; however, UV254 increased by 39 measurement units from 0.019/cm to 0.058/ cm, allowing clearer and more progressive description of the increase. Once treatment is sufficiently effective as to remove nearly all DOC (MF/NF), the ability to resolve differences in measured values exceeds even the sensitivity of UV absorbance and the relationship to DOC is also no longer reliable (R2 0.01, p-value 0.410). Importantly, though, the operational consequences arising from DOC at these

From the investigation into long-term water quality data from four pilot treatment plants incorporating advanced treatments for improved DOC removal from a common source water, key points can be identified: • DOC monitoring is important as an indicator of actual treatment plant efficiency; • Remaining DOC will react with chemical disinfectants, resulting in undesirable DBP formation; however, this can be minimised most easily through improved DOC removal; • UV absorbance is a simple, nondestructive, reagent-free water quality parameter; • UV absorbance at 254nm is a more suitable surrogate for DOC concentration and character than true colour and is effective within the range of modern treatment plant performance.

Table 2. The relationship between DOC and trihalomethane formation after 7-day chlorine contact at 30°C for treatment of Mt Pleasant source water. DOC 25/02/2010

UV254

Colour

THM

(mg/L)

(/cm)

(HU)

(µg/L)

Conventional

2.0

0.034

196

MIEX/Coag

1.2

0.017

102

MIEX/Coag/GAC

0.5

0.001

MF/NF

0.2

0.000

68 DECEMBER 2011 water

The Authors Rolando Fabris (email: rolando.fabris@sawater.com. au) is a senior researcher in the Water Treatment Unit, Australian Water Quality Centre, South Australian Water Corporation. Kalan Braun (Research Officer), Jim Morran, Lionel Ho and David Cook (Senior Research Officers), and Mary Drikas (Research Leader, Water Treatment) are all with the Australian Water Quality Centre, South Australian Water Corporation.

References Bennet LE & Drikas M, 1993: The Evaluation of Colour in Natural Waters. Water Research 27(7), pp 1209–1218. Chen J, Gu B, LeBoeuf EJ, Pan H & Dai S, 2002: Spectroscopic characterisation of the structural and functional properties of natural organic matter fractions. Chemosphere 48(1), pp 59–68. Chow C, Fabris R, Wilkinson K, Fitzgerald F & Drikas M, 2006: Characterising NOM to assess treatability. Water Journal 33(2), pp 74–85. Deflandre B & Gagné J-P, 2001: Estimation of Dissolved Organic Carbon (DOC) Concentrations in Nanoliter Samples Using UV Spectroscopy. Water Research 35(13), pp 3057–3062. Del Vecchio R & Blough NV, 2004: On the Origin of the Optical Properties of Humic Substances. Environmental Science and Technology 38(14), pp 3885–3891. Hur J, Williams MA & Schlautman MA, 2006: Evaluating spectroscopic and chromatographic techniques to resolve dissolved organic matter via end member mixing analysis. Chemosphere 63(3), pp 387–402. Kaplan LA, 2000: Comparison of three TOC methodologies. Journal of American Water Works Association 92(4), pp 149–156. Korshin GV, Benjamin MM & Li C-W, 1999: Use of differential spectroscopy to evaluate the structure and reactivity of humics. Water Science and Technology 40(9), pp 9–16. Korshin G, Chow CWK, Fabris R & Drikas, M, 2009: Absorbance spectroscopy-based examination of effects of coagulation on the reactivity of fractions of natural organic matter with varying apparent molecular weights. Water Research 43(6), pp 1541–1548. Krasner SW, Croué J-P, Buffle J & Perdue EM, 1996: Three approaches for characterizing NOM. Journal of American Water Works Association 88(6), pp 66–79. Langergraber G, Fleischmann N, Hofstaedter F & Weingartner A, 2004: Monitoring of a paper mill wastewater treatment plant using UV/VIS spectroscopy. Water Science and Technology 49(1), pp 9–14. Maitilainen A, Gjessing ET, Lahtinen T, Hed L, Bhatnagar A & Sillanpää M, 2011: An Overview of the Methods Used in the Characterisation of Natural Organic Matter (NOM) in Relation to Drinking Water Treatment. Chemosphere 83(11), pp 1431–1442.

technical features

wastewater systems

WASteWAteR SyStemS: DecentRAlISeD oR DIStRIbuteD? A review of terms used in the water industry R Watson Abstract Decentralised water services have been considered a poor or temporary alternative to centralised water servicing. Recently, a combination of governments seeking to diversify water sources, community sustainability drivers and technology improvements have resulted in decentralised systems being considered for urban wastewater treatment and recycled water provision. However, the terms “decentralised wastewater” and “decentralised water” have been used to describe a vastly diverse set of applications. The understanding of the key parameters of a decentralised system varies with the purpose, origin and application of the particular system. This variation makes it difficult to compare, discuss and analyse the performance and acceptance of decentralised systems. This paper reviews definitions from the literature, different Australian and international regulatory environments, Australian and international codes, and water utilities themselves. It specifically identifies key characteristics of a decentralised wastewater system. Recognising the broad range of alternatives covered by the term “decentralised” will help the industry appreciate why it is so difficult to make generalisations and comparisons in this area. It also highlights the importance of authors clearly stating the parameters covered by their work, rather than assuming a constant definition is understood.

Introduction Since the mid-19th Century best practice in water and wastewater has been to centralise services whenever it was economically and technically feasible (Gikas and Tchobanoglous, 2009). Centralised servicing collects water, usually far outside the urban area, and transports it through a large network of pipes to where it is used. Wastewater is transported out of the urban area, treated and usually discharged into a receiving water body. While this centralisation

has produced well documented and essential public health benefits (Gikas and Tchobanoglous, 2009; Harremoës, 1998) it has also resulted in significant capital investment and large complex systems. In recent times, the sustainability and resilience of single large systems has been questioned. Community sustainability drivers, supply constraints, water restrictions and technology improvements have led to the consideration of other service alternatives. Changes in social attitudes, financing arrangements and hydrological regimes are fuelling the drive for smaller, more flexible, systems. The term “decentralised water systems” can cover the entire range of water services, including: • Smaller water sources such as rainwater tanks and local groundwater extraction; • Local wastewater treatment, including on-site septic tanks and a range of different small wastewater treatment technologies; • Non-potable water supply including greywater diversion or treatment, stormwater recycling, wastewater recycling and groundwater recharge. Crites and Tchobanoglous (1998) describe decentralised systems as ones that collect, treat and use rainwater, stormwater, groundwater or wastewater at different spatial scales, from individual homes, clusters of homes, urban communities, industries or built facilities, and portions of existing communities either independent from, or as part of, a larger system. However, within the literature decentralised servicing can mean many different things. This makes it hard to compare and fairly consider decentralised systems in relation to better-understood conventional water and wastewater solutions. This paper recognises that decentralised water services cover the whole gamut of water services. However, it focuses on the use of the term

“decentralised” (and, later, “distributed”) in the literature, specifically in relation to decentralised wastewater and decentralised recycled water services. The paper summarises the commonalities and differences in the use of the term decentralised wastewater and discusses the significance of these variations. It also looks at some of the emerging trends in terminology and definitions as decentralised systems are installed as a complement or competitor to existing centralised networks. In 2009, Cook et al. explored the varying definitions of decentralised systems, outlined the key aspects of a decentralised approach and set a definition specific to the SouthEast Queensland perspective. This paper builds on Cook et al.’s work, but rather than try to develop a single allencompassing definition of decentralised systems it looks at key parameters that practitioners can use to clearly define the subset of decentralised systems they are discussing. The paper also seeks to clearly identify an emerging subset of decentralised systems that exist within or close to a large centralised network. One thing is clear: the range of definitions for decentralised systems is as wide ranging as the systems themselves. This reflects their great flexibility and adaptability to local needs, including demand, end uses, regulations, reliability of other supplies, costs of discharge, topography and population density.

Decentralised Wastewater Services One of the most widely used definitions of decentralised wastewater systems is taken from Crites and Tchobanoglous (1998): ‘Decentralised wastewater management may be defined as the collection, treatment, and disposal/reuse of wastewater from individual homes, clusters of homes, isolated communities, industries, or institutional facilities, as well as from portions of existing communities at or near the point of generation’

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wastewater systems This definition is representative of the wide range of terminology used in the literature when discussing decentralised systems. Terms used include: • Local treatment (Cook, 2009; NSW Department of Health, 2010); • On-site treatment (many, including Sydney Water, 2009; Geisinger and Chartier, 2005; US EPA, 2005; WERF, 2010); • Allotment (Mitchell and White, 2003); • Cluster (many, including Geisinger and Chartier, 2005; Mitchell, Abeysuriya and Willetts, 2008; US EPA, 2005; WERF, 2010; Willets, Fane and Mitchell, 2007); • Distributed systems (Cook, 2009; Mitchell, Abeysuriya and Willetts, 2008); • Community (Auckland Council; NSW Department of Health, 2010); • Development scale (Tchobanoglous & Leverenz, 2008); • Hybrid on-site (Tchobanoglous and Leverenz, 2008); • Satellite treatment plants (Gikas and Tchobanoglous, 2009; Tchobanoglous and Leverenz, 2008). In addition to using a wide range of terms, the definition of decentralised systems can vary depending on the specific immediate context. Yarra Valley Water’s (2009) discussion paper recognised that the terms “distributed”, “decentralised”, “on-site”, and “cluster” are used interchangeably to refer to wastewater treatment systems that operate outside the reticulated sewage network. Sydney Water’s sewer mining policy (2008) refers to decentralised wastewater treatment as a type of sewer mining that involves extracting domestic wastewater from a private sewer and treating it on site for reuse as recycled water. Sydney Water’s EIS for West Camden Sewage Treatment Plant (2001) upgrade and amplification considered three ‘decentralised’ options including: • On-site systems; • Community systems that were not connected to the centralised network; • A combination of on-site and community systems.

Key themes in Definitions Although the definition of decentralised wastewater can vary, there are some key similarities in the majority of definitions.

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These issues are similar to those found by Ackermann et al. (2001) and Pepermans et al. (2005) when they attempted to define distributed electricity generation. They both found it beneficial to look at the concepts used to describe the systems to better understand their components. Specifically, Pepermans et al. (2005) found that the lack of agreement on a precise definition was due to the concept including many technologies and applications in a range of environments (page 797), which is also the case for decentralised wastewater systems.

close Proximity of Wastewater Source, treatment and use/Disposal

The two most consistent concepts in decentralised wastewater systems were the proximity of the generation and/or treatment to use and smaller size. However, what represented small size and close proximity varied between authors. Other concepts varied in consistency, as will be discussed below. What emerged was not a single concept of decentralised systems, but more a moving continuum, where most agreed on what centralised and on-site systems were, with decentralised being somewhere in between (or including on site). The concept of a continuum somewhere between centralised and on-site was also discussed in Pinkham et al. (2004).

The idea of wastewater treatment being close to the waste generation, and the disposal or end use being close to the treatment, is well accepted in decentralised literature. Crites and Tchobanoglous (1998) use “at or near the point of generation” in their definition of decentralised.

The themes identified in decentralised wastewater definitions include: • Close proximity of wastewater source, treatment and use/disposal; • Smaller size and relationship to on-site systems; • Perception of improved sustainability; • Alternative management and ownership models; • Perception of inferior performance; • Greater variety in source, treatment and transport technologies and discharge locations; • Relationship of decentralised systems to centralised systems. These themes are not dissimilar to Pinkham et al. (2004), varying mainly in the inclusion of sustainability and performance perceptions and grouping together of treatment/discharge and sewer type. The final grouping reflects a subtle difference between the American and Australian experiences, particularly in recent years where technological, demand and cost advances have changed the technologies used both in decentralised treatment and centralised transport.1

According to the Oxford Dictionary, “decentralise” is “to undo the centralisation of”. The two definitions in Crites and Tchobanoglous (1998) are representative of this concept of decentralised being the opposite of centralised. They use networks to separate the two, with centralised systems having large and long transport networks and decentralised systems having little to no transport network.

In New Zealand, (Auckland Council) defines decentralised systems as: ‘The collection, treatment and disposal/ reuse of limited volumes of wastewater, generally from cluster(s) of dwellings and/or accommodation facilities that are usually located relatively close together, with the wastewater system relatively close to the source (also referred to as “community”, “neighbourhood” or “cluster” systems)’ [the author’s emphasis) Generally the overarching concept of proximity for generators to each other, generators to treatment and generators to end use is to keep systems small and local. It is very hard to specifically define and is referred to only in general terms (eg, relatively close, at or near).

Smaller Size and Relationship to on-site Systems While all definitions agree decentralised schemes are not centralised, many have variations within the “not centralised” component. Many of these explicitly exclude on site as a separate category (for example, see NSW Department of Health, 2010 and Tchobanoglous and Leverenz, 2008). Others, like Sydney Water (2009) and Geisinger and Chartier (2005), specifically include on-site systems under the banner of decentralised. This is perhaps another example of the advances in technology and new applications changing the understanding of terms. In the past, ‘on-site’ would generally refer to a single household; now on-site systems can refer to basement plants in large commercial or residential towers.

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wastewater systems Whether decentralised systems are assumed to include or exclude on-site systems, they all have an implied smaller scale than centralised systems. Occasionally the scale is specifically defined. This is more frequently done in standards or regulations. The US EPA (2005) definition suggests decentralised systems typically provide treatment on the property of individual homes or businesses. However, when scale is discussed explicitly in a definition it can vary considerably from only including on-site (US EPA, 2005), to including large recycled water schemes such as Rouse Hill (18,000 homes) in Sydney (Gordon, 2008). The Interim Final Queensland Guidelines for Decentralised Wastewater Systems (2007) (unpublished) were developed for systems with capacity from 21 to 1,000 EP (Cook, 2009). In Switzerland, treatment plants for less than 500 residents are considered as decentralised systems (Adler, 2006). NSW Department of Local Government, in its guidelines for on-site reuse for single dwellings, defines centralised and on-site systems (1998). It suggests centralised systems can be built to service from less than 10 to many thousands of households. This is the exception rather than the rule, as usually 10 houses would be considered decentralised. These examples show the wide range of scales the term decentralised systems cover.

such as the Green Building Council of Australia’s ‘Green Star Building Rating Tool’ have encouraged the use of decentralised recycled water systems.

Alternative management and ownership models Occasionally the management and ownership model is referred to. When it is, generally the more decentralised the system the more private the ownership and management structures. The larger and more centralised systems tended to have an assumption of public ownership and management. The Consortium of Institutes for Decentralized Wastewater Treatment (CIDWT) suggests cluster treatment systems are typically privately owned, community systems are publically owned and on-site systems are owned by individuals (2010). Cook et al. (2009) also suggested on-site systems were predominantly individually owned, cluster systems suggested some form of common ownership and distributed systems were operated by specialised utilities.

Perception of Inferior Performance and Increased Risk Decentralised systems, particularly onsite systems, have a poor performance perception. They have generally only been used at the fringes of traditional centralised servicing (Nelson, 2008) and

have often been viewed as a temporary or second-class measure. Governments throughout Australia (see, for example, Victorian AuditorGeneral, 2006) have identified and responded to the high levels of failing onsite systems (mainly septic tanks) through long and expensive centralised sewering programs.2 This response has reinforced the perception that centralising rather than improved management techniques is the best way to overcome the social (odour, amenity), health and environmental issues associated with these failing tanks. Advocates for decentralised services dispute decentralised systems present higher risks. Pinkham et al.’s (2004) review of risks concludes generally, the risk and cost of failure are less for decentralised as the consequences are small and widely distributed.

Greater Variety in Source, treatment and transport technologies and Discharge location The final area where decentralised systems were differentiated from centralised systems was the source and discharge methods. These concepts were not often referred to, but when they were, decentralised systems were generally seen as more flexible and capable of meeting the local needs and opportunities. A wide variety of sources for decentralised systems was evident

Perceptions of Improved Sustainability Nelson (2008) suggests that as integrated water solutions become the preferred way of servicing, decentralised technologies will become more dominant. Certainly within major Australian water utilities the process of integrated water planning has spurred the consideration, if not the implementation, of decentralised water and wastewater alternatives.

This is reflected in current trends in Australia. Voluntary green building codes

Decentralised definitions often included perceptions of greater sustainability and opportunities for recycling (see Venhuizen, 1986, for example). Results from Cook et al.’s (2009) interviews with industry practitioners in Australia reiterated that the concept of decentralised treatment included being fit for purpose and sustainability objectives, including better integration of services and water-sensitive urban design.

The distributed recycled water system at Pennant Hills Golf Club in NSW.

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wastewater systems in the literature, including rainwater, groundwater, stormwater and wastewater – either blackwater or greywater. This was most evident in Cook et al. (2009), where decentralised systems were identified as being more independent than centralised systems, as they did not rely on a single source. Some descriptions of decentralised wastewater systems were specific about where decentralised systems discharged (eg, to the ground, irrigation or recycling) as opposed to centralised systems that generally discharged to open water bodies (Pinkham et al., 2004). Gikas and Tchobanoglous (2009) suggested that satellite treatment plants often lack solids processing and the solids are returned to the network.

Relationship of Decentralised Systems to centralised Systems Many definitions excluded connection to the centralised network, either explicitly (for example, Sydney Water, 2001) or implicitly by using isolation as a requirement or an assumed reason for the systems (see WERF definition). The assumption that decentralised systems are isolated and remote from centralised networks reflects their historical role. Until recently most decentralised systems, particularly in the United States, were in hard-toservice or remote places and used septic tanks and ground-leaching trenches for disposal. In recent years decentralised systems have begun to be used in conjunction with centralised systems to save energy and to provide a valuable non-potable water source. Green Building Council of Australia’s Green Star Rating System, which allocates points for on-site recycling and reuse, has helped make on-site systems more popular. This has been made possible by the advances and commercialisation of more small-scale treatment systems. More recent literature identifies the potential for decentralised systems to integrate with the centralised network (see Cook, 2009, for example). Some of the benefits, concerns and issues associated with decentralised systems on or close to a centralised network are very different from remote schemes. To try and differentiate these schemes, some authors use alternative terms. Gikas and Tchobanoglous (2009) define satellite treatment plants as being within the network and decentralised treatment plants as being off the network. Since about 2008 the term “distributed”

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has been used in Australia (Mitchell, Abeysuriya and Willetts, 2008). This s a term also used in the electricity industry (see Ackermann, Andersson and Söder, 2001; Pepermans et al., 2005 for distributed electricity definitions). “Distributed wastewater” or “recycled water” in recent literature has been used to describe small local schemes within or near a centralised network. Chung (2008) considers a distributed wastewater scheme in which multiple satellite WWTPs are located throughout a community with the ability to treat and distribute reclaimed water to nearby users. WSAA guidelines for distributed systems (WSAA, 2010), recent CSIRO documents (see, for example, CSIRO 2008, 2009; Tjandraatmadja et al. 2008), and Mitchell, Abeysuriya and Willetts (2008) all use the term “distributed” to refer to small/ local wastewater treatment plants within or close to a centralised network. The term “distributed” is useful as it clearly distinguishes schemes with the ability to connect to a centralised network or within the centralised service area. These schemes are likely to have different considerations to isolated schemes. It is also consistent with the terminology in the electricity sector. However, writers should acknowledge it is not widely used or recognised yet in relation to wastewater and recycled water, making a clear statement of purpose and definition at the outset particularly important.

conclusion This paper has highlighted that the use of the term “decentralised system” in the water and wastewater context varies as widely as the application. The flexibility of decentralised systems to provide the best solution for the specific local circumstances, (ie, size, treatment technology, water sources, end uses) makes it difficult to fit them within a concise definition. Although the use of the term varies widely, most would agree that decentralised systems are used in a local context where the source, treatment and reuse occur close to each other. As decentralised technology has become more reliable and affordable, it has progressed from a second rate system for poor and remote communities to one that is increasingly installed in prestige buildings to meet ‘green building requirements’ and demands for recycled water. Perhaps most reflective of the growth and diversification of the industry is the emergence of the term “distributed

systems” to reflect systems adjacent to, and in competition with, large centralised networks. Some authors have provided simplified (eg, Crites and Tchobanoglous, 1998) or more detailed and inclusive definitions (eg, Cook, 2009). However, the current literature is inconclusive about many details such as size, connection to the centralised network, management and ownership structures, and principles of sustainability. Rather than working on setting an allencompassing definition, it is suggested that authors be aware of the large range that the term decentralised can cover and be specific and clear when describing the systems they are discussing. As a starting point the size (system, area of service and population), treatment type, location in relation to a centralised network, water sources and sustainability goals, and any specific management or ownership structures should be clearly stated.

the Author

Rachel Watson (email: Rachel.watson@ uts.edu.au) is a PhD student at the Institute of Sustainable Futures at UTS, Sydney. Rachel is supervised by Professor Cynthia Mitchell and Dr Simon Fane. The PhD is titled: The Full Range of Costs and Benefits of Decentralised Recycled Water Systems and is kindly sponsored by Sydney Water. Rachel is currently seeking sites to be involved in her study. If you are interested, or would like to know more, please contact Rachel via email.

References 1. See Stanwell Park, Coalcliff, Otford and Stanwell Tops in Wollongong’s North, attached to the centralised gravity network of Sydney Water’s Cronulla System, as an example of an alternative sewer attached to a centralised network. Also, most decentralised systems installed in Sydney are membrane bioreactors (MBR), as opposed to Pinkham’s observation that most centralised systems use activated sludge processes and decentralised systems use alternatives such as sand and trickling filters. 2. See Victorian backlog sewer program and Sydney Water Priority Sewerage Program for examples. Ackermann T, Andersson G & Söder L, 2001: ‘Distributed generation: a definition’, Electric Power Systems Research, Vol 57, No 3, pp 195–204. Adler C, 2006: ‘Market Potential of a Membrane Based Wastewater Treatment Plant for Decentralized Application in China’, Masters

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wastewater systems Diploma Project 12/2006–04/2007 thesis, Swiss Federal Institute of Technology. Anon 2010: Oxford English Dictionary Online, Second Edition, Oxford University Press, www.oed.com.ezproxy.lib.uts.edu.au/view/ Entry/48128#eid7320676 Auckland Council: Wastewater definitions, website, viewed 10 August 2010, www.arc.govt.nz/ environment/water/wastewater/wastewaterdefinitions.cfm Chung G, Lansey K, Blowers P, Brooks P, Ela W, Stewart S & Wilson P, 2008: ‘A general water supply planning model: Evaluation of decentralized treatment’, Environmental Modelling & Software, Vol 23, No 7, pp 893–905.

Pepermans G, Driesen J, Haeseldonckx D, Belmans R & D’Haeseleer W, 2005: ‘Distributed generation: definition, benefits and issues’, Energy Policy, Vol 33, No 6, pp 787–98. Pinkham R, Hurley E, Watkins K, Lovins A, Magliaro J, Etnier C & Nelson V, 2004: Valuing Decentralised Wastewater Technologies: A Catalogue of Benefits, Costs, and Economic Analysis Techniques. Prepared by Rocky Mountain Institute for the US Environmental Protection Agency (USEPA).

Sydney Water, 2008: Sewer Mining Policy, Sydney Water, Sydney, viewed February 2011, www.sydneywater.com.au/ Water4Life/RecyclingandReuse/pdf/ SydneyWatersSewerMiningPolicy.pdf.

Crites RW & Tchobanoglous G, 1998: Small and decentralized wastewater management systems, WCB/McGraw-Hill, Boston.

Sydney Water, 2009: Water Conservation and Recycling Implementation Report, Sydney Water Corporation.

CSIRO, 2008: Distributed water harvesting and recycling technologies, viewed 3 March 2011, www.csiro.au/resources/greywater.html

Tchobanoglous G & Leverenz H, 2008: ‘The role of on-site and decentralised wastewater management in the twenty-first century’, paper presented to the On-site and Decentralised Sewerage and Recycling Conference, Benalla, Victoria, Australia, October 2008.

Geisinger D & Chartier G, 2005: ‘Managed on-site/ decentralised wastewater systems as long-term solutions’, Clearwaters, No 35, pp 6–11.

The Consortium of Institutes for Decentralized Wastewater Treatment (CIDWT), 2010: Decentralized Wastewater Glossary, viewed 19 August 2010, www.onsiteconsortium.org/ glossary.html

Gikas P & Tchobanoglous G, 2009: ‘The role of satellite and decentralized strategies in water resources management’, Journal of Environmental Management, Vol 90, No 1, pp 144–52.

The US EPA, 2005: Decentralised treatment wastewater systems – A Program Strategy, USEPA.

Gordon M, 2008: ‘Hurdles to an emerging onsite industry’, paper presented to the On-site and Decentralised Sewerage and Recycling Conference, Benalla, Victoria, Australia, October 2008.

Tjandraatmadja G, Cook S, Sharma A, Diaper C, Grant A, Toifl M, Barron O, Burn S & Gregory A, 2008: ICON Water Sensitive Urban Developments – Evaluation of existing icon water sensitive urban developments to identify gaps in knowledge and lessons learnt for future developments, CSIRO.

Harremoës P, 1998: ‘Upgrading our inherited urban water systems’, Water Science and Technology, Vol 37, No 9, pp 1–8.

Venhuizen D, 1986: The decentralized concept of “waste” water management, viewed 3 March 2011, www.venhuizen-ww.com/

Mitchell C, Abeysuriya K & Willetts J, 2008: ‘Institutional arrangements for on-site and decentralised systems: needs and opportunities for key players in the field of distributed wastewater management’, On-site and Decentralised Sewerage and Recycling Conference, Benalla, Victoria, Australia, October 2008.

Victorian Auditor-General, 2006: Auditor-General’s report: Protecting our environment and community from failing septic tanks, Victorian Government.

Mitchell C & White S, 2003: ‘Forecasting and backcasting for sustainable urban water futures’, Water Journal, Vol 30, No 5, pp 25–30. Nelson VI, 2008: New Approaches in Decentralized Water Infrastructure, Coalition for Alternative Wastewater Treatment.

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PATENT-PENDING

Sydney Water, 2001: West Camden Sewage Treatment Plant Upgrade and Amplification Environmental Impact Statement – Summary, AWT ES&T Pty Ltd for Sydney Water Corporation, dated 14 November 2001.

Cook ST, Grace Ho A & Sharma A, 2009: Definition of decentralised systems in the south east Queensland context. Urban Water Security Research Alliance, City East, Qld.

CSIRO, 2009: National Distributed Urban Water Systems: Performance Verification Cluster Specification, viewed 3 March 2011, www.csiro.au/ resources/Urban-Water-Cluster-Specification.html

New high-pressure mechanical piping system for the SWRO market

WERF, 2010: Decentralised Wastewater Treatment System, website, viewed 20 August 2010, www. werf.org/AM/Template.cfm?Section=Decentralized_ Systems&TEMPLATE=/CM/HTMLDisplay. cfm&CONTENTID=10288 Willets J, Fane S & Mitchell C, 2007: ‘Making decentralised systems viable: a guide to managing decentralised assets and risks’, Water Science and Technology, Vol 56, No 5, pp 165–173.

NSW Department of Health, 2010: Wastewater and Sewage, website, viewed 18 August 2010, www. health.nsw.gov.au/PublicHealth/environment/ water/wastewater.asp

WSAA, 2010: Privately Owned Recycled Water Systems, website, viewed October 2010, https://www.wsaa.asn.au/Publications/ Documents/Privately%20Owned%20 Recycled%20Water%20Systems.pdf

NSW Department of Local Government, 1998: Environment and health protection guidelines : on-site sewage management for single households, Dept of Local Government, Bankstown, NSW.

Yarra Valley Water, 2009: Discussion Paper, Management Framework for Distributed Wastewater Systems in High Density Developments, Yarra Valley Water, Victoria.

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refereed paper

WAter QUALItY IMPACtS ON eStUArINe AQUACULtUre: A reVIeW Standard designs for on-site wastewater systems have been developed and, where implemented, impacts have been reduced PM Geary, JH Whitehead Abstract In recent years, oyster harvesting in a number of rivers, estuaries and coastal lakes on the mid-north coast of NSW has been adversely impacted by reduced water quality. Since 1997 Wallis Lake, Tilligerry Creek (part of the Port Stephens estuary) and, more recently, the Kalang River, have been closed to oyster harvesting. In particular, following periods of heavy rain, water quality in the estuaries has diminished and a number of incidents of pathogen contamination of estuarine waters have occurred. Such incidents have significant adverse impacts on the oyster industry and may result in long periods of closure to harvesting with consequent implications for oyster supply and the livelihoods of those employed in the oyster industry. On-site wastewater management systems (OWMS) on properties close to the estuary have often been considered possible sources of contamination of estuarine waters. State Government agencies have broad responsibilities for public and environmental health and in the oversight of shellfish quality, while local Councils are responsible for the approval and ongoing operation of OWMS. Studies by the authors and State Government agencies, such as the NSW Food Authority which manages the Shellfish Quality Assurance Program along with local Councils, have attempted to use a range of methods to demonstrate connectivity of failing OWMS to the estuaries. Systematic audits of these systems in some catchments have quantified the extent to which they do not meet current regulatory requirements and have been used to develop a risk-based approach to assessment of the wider extent of the problem. Pathogen die-off modelling has been used to assess risk and determine the need for upgrading or replacement of existing OWMS. Standard designs have

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been developed and implemented in some catchments to ensure a higher level of performance and there is clear evidence that, where these designs have been implemented, impacts have been reduced.

Introduction Wastewater management in small communities may involve a reticulated system with centralised treatment and water-based discharge or, in some cases, land application involving reuse of the treated effluent. Where the cost of a reticulated system is prohibitive to small communities, wastewater may be treated and disposed of on-site at individual properties (OWMS systems). Typically in these situations, a septic tank and land application system involving subsurface trenches or beds is commonly used, although other designs are available. There are over one million OWMS in Australia (Gardner et al., 2006) and surveys and audits of their performance often demonstrate that a proportion (15â&#x20AC;&#x201C;40%) may periodically perform poorly or even fail due to poor construction, undersizing with respect to hydraulic loads, or soil and land capability constraints for on-site effluent

disposal. Where these failures occur there is concern with respect to public health and the environment; however, there are very few studies that are able to demonstrate direct linkages between OWMS failures and any adverse impacts to human health and receiving waters. The inability to discern such linkages and widespread contamination which may be anticipated due to these failures is partly due to effluent dilution, difficulties which exist in differentiating effluent pathways in the field, and the attenuation of faecal contaminants.

Case Studies In NSW there have been a number of highly publicised cases of contamination of estuarine waters used for oyster growing along the coastline north of Newcastle. In each case possible sources of human faecal and elevated nutrient concentrations have been found to come from agricultural areas, waterway users, runoff from urbanised areas and unsewered small communities. It has proven difficult to separate the overall impact that these small communities have to estuarine water quality in comparison with agriculture;

Oyster beds in Tilligerry Creek Estuary, Port Stephens, NSW.

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small wastewater systems responses In response to the outbreak in the Wallis Lake estuary, a number of Local and State Government agencies collaborated in estuary and catchment remediation works. Over the 13 years since the incident, these works have resulted in significantly improved estuarine water quality and commercial oyster growing is again thriving. In 2004 the Great Lakes Council was awarded a major prize for best practice in river and catchment management and environmental repair in Australia (Kardamanidis et al., 2009), although the actual source of the contamination incident has never been identified.

An aerial photo of Wallis Lake Estuary. however where human viruses are found in estuarine filter feeders such as oysters, a human source of contamination such as failing OWMS or sewerage treatment plant discharge has to be responsible. In January 1997 in Wallis Lake, a Hepatitis A virus affected approximately 274 people in NSW (one fatally) and, in all, 422 people throughout Australia. In a subsequent investigation by NSW Health, it was concluded that the oyster contamination was waterborne and potentially from contamination by human faecal waste (Kardamanidis et al., 2009). While the estuarine waters were contaminated by human faecal and nutrient pollution from unsewered small communities and other sources, the specific source of the waste was not able to be determined. Failing OWMS were, however, considered highly likely to have been primarily responsible due to their reported high rates of failure and the large number of unidentified unsewered premises in the catchment.

More recently, in 2008 outbreaks of gastroenteritis have been linked to a common batch of oysters harvested from the Kalang River estuary in northern NSW. The presented symptoms were consistent with Norovirus infection and the estuary subsequently closed to the commercial harvesting of oysters by the NSW Food Authority. Investigations are still underway as to the source or sources of the human faecal contamination and the estuary still remains closed to harvesting. Possible human sources of the contamination are considered to be a number of OWMS adjacent to the estuarine waters and a downstream sewerage treatment plant discharge from a nearby community wastewater system.

In response to the closure of the Tilligerry Creek estuary to oyster harvesting, a sanitary survey of the estuary and river shorelines was conducted by the NSW Food Authority and Port Stephens Council undertook OWMS inspections. An audit of approximately 300 OWMS in the community adjacent to the estuary found that a small number of systems were faulty and that human effluent had the potential to contaminate ground and surface estuarine waters where the oysters were grown and harvested. In this study a number of individual OWMS were dosed, using bromide and lithium salts and fluorescein dye to determine whether direct linkages existed between the OWMS and surface and groundwaters.

In July 2005 part of the Stateâ&#x20AC;&#x2122;s second largest producer of oysters with an annual value of A$5 million (behind Wallis Lake with an annual value of A$14 million) was closed to commercial oyster harvesting due to a similar contamination incident. Samples of oyster tissue tested positive using PCR analysis for human Adenovirus and Norovirus in the Tilligerry Creek estuary in Port Stephens. In this case (as in Wallis Lake), faecal contamination from failing OWMS was considered responsible, although agricultural sources of contamination were also significant in terms of the overall faecal load to the estuary. The estuary remained closed to commercial harvesting for over two years, resulting in a substantial loss of income from which the industry in that region has yet to recover.

Aerial photo of an upstream part of Tilligerry Creek Estuary, Port Stephens, showing mixed land uses.

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faecal sterols and various pharmaceutical compounds. Fluorescent whitening compounds (FWCs), which are present in the majority of wastewaters containing laundry products, are also now being assessed as studies elsewhere (Gilpin et al., 2002) have shown that they too can be used to assist with identifying human faecal sources in environmental water samples.

In several of these cases hydraulic pathways to the estuary were confirmed, indicating that contaminated groundwater from OWMS was entering surface drains and quickly entering the estuary following heavy rainfall events (Geary, 2005). More detailed investigations followed to identify the sources of faecal contamination that an unsewered development was making to both surface runoff and groundwater entering the estuary. In addition to the microbial faecal indicators regularly used in such studies, water samples were collected and analysed for faecal sterol compounds in order to determine whether faecal contamination was human-derived. Interpretation of the various sterol compounds indicated that while there had been occasions where humanderived faecal contamination had entered the estuary, the majority of the faecal contamination at that time was sourced from herbivores in the catchment upstream (Geary et al., 2007). While the estuary was closed, estuary and catchment remediation works were initiated by the local Council. A catchment management plan was commissioned which recommended a number of improved management practices be adopted and an estuary response model developed. When a sewerage options study indicated that the cost of a reticulated system for the small community adjacent to the estuary was prohibitively expensive, a number of standard designs for improved OWMS were developed and failing systems were required to be upgraded. One of the OWMS designs adopted by Council which has proved very successful in overcoming the problems associated with the high groundwater table is the sand (Wisconsin) mound. These systems are considered secondary treatment systems, as primary-treated effluent is pumped into an above-ground distribution system constructed in imported permeable soil. Effluent then percolates through this material where treatment occurs prior to it entering the groundwater. As a mitigation measure, 58 mounds which receive primary treated effluent, and nine which receive secondary-treated effluent from aerated treatment systems, have been constructed. Monitoring has shown that the overall efficacy of the treatment system can be directly linked to the increased vertical separation distance to the groundwater provided by the mound and the periodic dose loading of effluent from the septic tank (Whitehead and Geary, 2009).

76 DECEMBER 2011 water

refereed paper

A Wisconsin Mound OWMS. Similar audits conducted in the Kalang River estuary have found that a number of OWMS which have been approved by the local Council are failing. Studies have been undertaken using tracers such as fluorescein, rhodamine and bromide, along with microbiological faecal indicators, to determine the source of the human contamination in the estuary waters. While there are unsewered and sewered urban settlements adjacent to the river, and a variety of other agricultural land use activities upstream which may be contributing to the faecal contamination detected in these oyster-growing areas, the source of the human contamination has yet to be found and the estuary remains closed to oyster harvesting. This situation, as in the former example, has had a profound effect on the commercial viability of the oyster growing industry in each of these estuaries and a consequent loss in consumer confidence in the product. There are also other estuaries where there is concern with respect to the increasing faecal bacterial counts in oyster-growing waters and the potential which exists for contamination to be human-derived from adjacent or nearby small unsewered communities.

Conclusion Demonstrating direct linkages between the wastewater management practices of small communities and estuarine water quality is difficult at the catchment scale and may not be possible using standard monitoring techniques and typical microbiological indicators. While Gardner et al. (2006) has suggested that there is little evidence of the impact that unsewered communities have on water quality, the fact that human viruses can periodically be found in oysters suggests current monitoring programs at high-risk estuary locations need to be improved. In developing new monitoring programs, consideration should be given to either more regular assays for human viruses in oysters, or in measuring chemicals associated with human metabolism and activity, which can also be present in human faecal material such as caffeine,

Contamination incidents such as those discussed in this paper demonstrate the close relationship and the sometimes inherent conflict between managing wastewater in small communities, increasing urban and rural development, and the need to maintain estuarine water quality so that aquaculture such as oyster growing can be undertaken without compromising human health.

the Authors

Phil Geary (email: phil.geary@newcastle. edu.au) is an Associate Professor at the School of Environmental & Life Sciences, University of Newcastle, NSW. Joe Whitehead (email: joewhitehead@ whiteheadenvironmental.com.au) is Principal of Whitehead and Associates Environmental Consultants, Director of the Centre for Environmental Training and Senior Lecturer at the University of Newcastle.

references Gardner E, Vieritz A & Beal C, 2006: Are on-site systems environmentally sustainable? Water, 33(1), pp 36–46. Geary PM, 2005: Effluent tracing and the transport of contaminants from a domestic septic system, Water Science and Technology, 51(10), pp 283–290. Geary PM, Lucas SA, Dunstan RH & Coombes PJ, 2007: Distinguishing wastewater contamination from on-site systems in mixed land use watersheds, In 11th National Symposium on Individual and Small Community Sewage Systems Proceedings (Ed. K. Mancl), American Society of Agricultural Engineers, St Joseph, Michigan, US. Gilpin BJ, Gregor JE & Savill MG, 2002: Identification of the source of faecal pollution in contaminated rivers, Water Science and Technology, 46(3), pp 9–15. Kardamanidis K, Corbett SJ & Zammitt AP, 2009: Hepatitis A: Wallis Lake revisited, NSW Public Health Bulletin, 20(1–2), pp 29–30. Whitehead J & Geary PM, 2009: Sand mounds for effective domestic effluent management, Water, 36(1), pp 27–32.

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RELIABLE LOW TECHNOLOGY FOR POLLUTION CONTROL IN SEMI-RURAL MOROCCO AND JORDAN Beneficial products include irrigation water, reeds and dried biosolids for soil amendment T Young, R Copithorn, J Karam, O Abu-Rayyan Summary Operating experience at municipal wastewater treatment plants (WWTPs) in Morocco was used to develop design criteria and operating procedures for the construction of two new WWTPs in Shobak and North Shouneh, Jordan, to treat septage from small communities to water reuse standards. The WWTPs use an anaerobic/settling digestion tank, facultative lagoons, intermittent or recirculating sand filters, and reed beds to remove solids, carbon, nitrogen and pathogens. The facilities are sustainable in that they minimise the use of complex mechanical and electrical equipment, do not require chemicals or high electrical demands, and produce beneficial products for the communities, which include irrigation water, reeds and dried biosolids that can be used as a soil amendment and, as such, may be suitable for consideration in similar climates in Australia, dependent on local regulations.

Introduction Rural areas in developing countries are best served by treatment facilities that do not require complex mechanical processes and that minimise power costs, chemical usage and operational requirements. In addition, treatment facilities in arid areas that choose to reuse the treated effluent must reliably provide a high level of treatment in order to protect public health. Reuse standards for nitrogen can prove particularly challenging to achieve without complex systems. This paper presents experience with the design and operation of treatment facilities in Morocco and Jordan that are using relatively simple lagoon and fixed film processes to achieve ammonia and nitrogen removal to meet various reuse standards. The treatment plants presented include Ben Sergao and Drarga

(Morocco), and Shobak and North Shouneh (Jordan). The experience gained at these facilities provides design and operational guidance relevant to treating both high-strength domestic wastewater and septage to achieve nitrogen limits to meet reuse standards.

General Description of Treatment Processes

Reed beds at Drarga.

Solids and carbon removal Manually cleaned coarse screens are used at all facilities for preliminary treatment. For facilities treating moderate to highstrength domestic wastewater, anaerobic lagoons provide the initial treatment step for solids and carbon removal. For facilities treating septage, anaerobic/ settling digestion tanks are used for solids removal and digestion. The initial treatment units are covered to maintain warmer temperatures and minimise odours. Although methane collection from these lagoons was evaluated and included in the treatment plant designs in Morocco, the systems are no longer used due to inconsistent gas quantities and poor gas quality (hydrogen sulfide). Based on this experience and low electricity prices, methane gas collection and reuse was not designed for facilities in Jordan.

Nitrification A biofilm process was selected as the technology for nitrification because these systems are simple, reliable and cost less to operate than suspended growth systems. Two of the facilities presented

use intermittent sand filters and two of the systems use recirculating sand filters for nitrification as well as additional solids and carbon removal. Upstream lagoons prevent excessive solids from prematurely clogging the filters. Operating procedures were developed to control the accumulation of biomass and to maintain an adequate level of oxygen in the sand filters for nitrification. The primary source of oxygen in the sand filters is diffusion of oxygen into the upper layers of the sand from the air. This effect is enhanced by frequent â&#x20AC;&#x153;tillingâ&#x20AC;? of the sand on the surface. The tilling process involves turning the top 5 to 7 centimetres of sand to expose the bacteria growing on the sand grains to the surface air. The tilling process also breaks up the hard pan of solids and algae that tend to build up on the surface over time. Some oxygen will also enter the bottom of the sand filters through the open underdrains and their riser vent pipes. Flow-holding basins upstream of the sand filters hold and dose the flow intermittently, allowing the filters some time to rest and re-oxygenate.

water

DECEMBER 2011 77

small wastewater systems Plant Bypass

Plant Influent

Plant Influent Diversion Structure

Influent Screen

Anaerobic Lagoon

Structure Flow Holding Basin

Figure 1. Process flow schematic of the Ben Sergao wastewater treatment facility. Denitrification Nitrification in the sand filters generates nitrates. To achieve water reuse standards, the concentration of nitrates must be significantly reduced. At the Drarga and North Shouneh WWTPs, denitrification is required because these facilities provide year-round water reuse. At Drarga, denitrification is accomplished in denitrification lagoons, while at North Shouneh concrete denitrification reactors are located immediately downstream of the anaerobic/settling digestion reactors. Nitrified effluents from the sand filters for both facilities are recycled to the denitrification processes where an anoxic environment is maintained for the conversion of nitrate-nitrogen to nitrogen gas by heterotrophic organisms. Carbon required for denitrification at both facilities is provided by the influent wastewater.

Effluent polishing In three of the facilities, discharge from the sand filters flows through reed beds (man-made constructed wetlands) to further reduce organics, nitrogen, solids and pathogens. Reeds from these beds can be harvested and sold several times per year.

Discussion of Individual Treatment Plants Ben Sergao pilot plant, Morocco A pilot WWTP was built in the southern Agadir suburb of Ben Sergao in 1989 through a combination of local, state and French foreign aid funding. The

Anaerobic Lagoons

Denitrification Lagoons

Recirculating Sand Filters

Reed Beds

Effluent Holding Basins

Reuse Water for Crop Irrigation

Nitrate Recycle

Figure 2. Drarga Wastewater Treatment Plant Schematic. Plant Effluent

Effluent Flow Monitoring Station

Intermittent Sand Filters

Screening & Grit Removal

Filter Dosing Basin

Settling/Digestion Reactors Septage Receiving Station

Anaerobic/Settling Lagoons

Reed Beds Intermittent

Evaporation Ponds

Figure 3. Schematic of the Shobak Jordan WWTP.

goal of the Ben Sergao pilot project was to demonstrate the feasibility of using anaerobic lagoons and intermittent sand filters for domestic wastewater treatment in an effort to minimise operational and maintenance costs by limiting the use of complex mechanical and electrical equipment. The pilot plant has a treatment capacity of 750m3/d and features an influent manually-cleaned bar screen, a 1,500m2 anaerobic lagoon, a 250m3 flow-holding basin and five 1,500m3 intermittent sand filters. The flow-holding basin is used to control the flow discharged to the sand filters. Each sand filter is active for three days and at rest for two days. Therefore, the treatment facility is operated with a 2.0 day hydraulic retention time (HRT) in the anaerobic lagoon and an intermittent sand filter dosing rate of 167mm. A process flow schematic of Ben Sergao is shown in Figure 1. Plant performance data is presented in Table 1. The Ben Sergao WWTP is within close vicinity to the Municipality of Drarga. As a result of the successful operation of the Ben Sergao WWTP, local and regional government officials desired to use the Ben Sergao WWTP as a model for the proposed Drarga wastewater treatment facility. Operational data and experiences from the Ben Sergao facility were used to develop the design for the Drarga facility. The familiarity of local Drarga officials with the Ben Sergao facility simplified â&#x20AC;&#x153;buy-inâ&#x20AC;? to the project, while the close proximity of the Drarga facility to the Ben Sergao

facility provided training opportunities for Drarga operational staff and laboratory personnel.

Drarga, Morocco The municipality of Drarga is located in a semi-arid region near the coast of southwest Morocco. Water resources in the area had been exhausted by construction of the Abdelmoumen Dam, continuing drought conditions, increased population and the excessive use of groundwater. As part of the Water Resources Sustainability (WRS) project, jointly funded by the United States Agency for International Development (USAID) and the Moroccan Ministry of the Environment, a wastewater treatment facility and water reuse system for the area was developed. The wastewater treatment facility was designed in compliance with the World Health Organization standards for unrestricted agricultural irrigation water. Unit processes for the wastewater treatment facility consisted of influent screening, grit removal, two 918m2 anaerobic lagoons, two 736m2 denitrification lagoons, 101,560m2 recirculating sand filters and two 2,900m2 reed beds. The anaerobic and denitrification lagoons were designed for a 3.0 day and 2.4 day HRT, respectively. Each sand filter is dosed once every five dosing periods. There are three dosing periods each day at a rate of 230mm per fill. The recycle rate from the sand filter effluent to the denitrification lagoons is 1,470m3/d.

Table 1. Ben Sergao WWTP performance (1995). Influent

Anaerobic Lagoon Effluent

Final Effluent

Removal Efficiency

BOD5 (mg/L)

347

132

5.5

98.4%

COD (mg/L)

1,072

450

95.7%

TSS (mg/L)

440

132

1.9

99.6%

TKN (mg/L)

174

126

90.2%

157.1

N/A

Parameter

NO3TP (mg/L) Fecal Coliforms (MPN/100 mL) Nematodes (No./L)

78 DECEMBER 2011 water

27.7

4.5

17.5

36.8%

5.1 x 109

2.1 x 108

134

7.5 Log Units

139

100%

Operators monitoring effluent quality at Shobak.

technical features

small wastewater systems No chemicals or complex Table 2. Drarga WWTP Performance (2005). mechanical equipment Anaerobic are used in the treatment Parameter Influent (mg/l) Lagoons (mg/l) process. Treated effluent from the facility is stored on-site BOD 320 180 – 240 in lined basins and available COD 712 410 – 550 for sale to local farmers for TSS 336 110 – 180 irrigation water. Effluent not sold is discharged to the TN 89 N/A Oued River. In addition to the NO3-N N/A N/A sale of reuse water, income is NH3-N 72 N/A also received from the sale of reeds harvested from the reed 12 N/A TP beds at the treatment facility N/A F.C. (MPN/100ml) 1.1 – 2.0 x 108 twice per year. Sludge from Nematodes (eggs/l) 7.5 N/A the lagoons is sent to drying beds and disposed of twice for Water Reuse and came to the attention a year (total volume about of water officials in Jordan. 100–120m3/year). The facility became operational in 2001 and was initially Jordan treatment facilities owned by the municipality and operated In 2004, the USAID, in conjunction with by a locally organised group, the Al Amal the Water Authority of Jordan (WAJ) Association. Ownership and operations initiated the Small Communities Project were transferred to the Office National de (SCP). The SCP was conceived to l’Eau Potable (ONEP) in 2004. Figure 2 provides an illustration of the process flow provide centralised wastewater treatment with beneficial reuse opportunities schematic for the treatment facility. for rural communities in Jordan using The Drarga WWTP was initially low-maintenance technologies such as designed for an average daily flow those proven at the Drarga, Morocco, capacity of 607m3/d. Actual flow to the WWTP. The communities selected for facility has been much higher – averaging this project included the areas of Shobak between 1,800 and 2,700m3/d. However, and North Shouneh, which did not have the influent has been more dilute than wastewater collection systems and relied initially designed (actual influent average on cesspools for wastewater treatment COD of 712 mg/L vs. 1,441 mg/L design and disposal. basis) and the plant has continued to To avoid the high cost of sewers for meet performance goals despite the lower density populations and to be able higher flow. Plant performance data to serve clusters of small communities, is presented in Table 2. The success both treatment facilities are designed to of the Drarga WWTP operation was internationally documented in publications treat only septage, which is delivered to such as the United States Environmental the plants by contract septage haulers Protection Agency’s (US EPA) Guidelines serving the local communities. Both

Denitrification Lagoons (mg/l)

Reed Beds (mg/l)

25 – 45

N/A

65 – 110

N/A

4.2 – 55

N/A

9.39 – 106

0.9 – 23.10

20 – 44

2.25 – 22.4

6.13 – 22.5

0.16 – 1.79

2.02 – 8.90

2.08 – 4.64

4.6 x 103 – 1.1x105

4.3x102 – 9.3x102

N/A

facilities are designed to serve the selected municipalities and some of their nearby communities until 2028. During the initial years of operation, they will be able to accept septage from a wider service area including several adjacent municipalities. Table 3 summarises the septage characteristics which served as the influent design basis for the North Shouneh and Shobak WWTPs. Due to the scarcity of potable water in this region, the potential for effluent reuse was a guiding principle in the design of these facilities. Jordanian Irrigation Reuse Standards (JS 895/2006) limits are shown in Table 4.

Table 3. Projected septage characteristics. Description

Value

TSS (mg/L)

6424

BOD (mg/L)

1850

COD (mg/L)

7353

TKN (mg/L)

322

Salinity (mg/L)

1300

Table 4. Jordanian Irrigation Reuse Standards (JS 895/2006). Irrigation Class (JS 893/2006) Class A (Cooked Vegetables, Parks & Landscaping/ Roads in Towns)

Class B (Fruit Trees, Sides of Roads, Green Areas)

Class C (Fodder & Industrial Crops & Forest Trees)

Cut Flowers

BOD

200

300

COD

100

500

Parameter (mg/l)

TSS

200

300

100

F.C. (MPN/100ml)

100

1,000

n/a

< 1.1

Nematodes (eggs/l)

≤1

NO3-N

7.8

11.8

18.3

11.8

D.O.

n/a

6–9

n/a

pH Turbidity (NTU) FOG

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small wastewater systems Table 5. Shobak WWTP performance (November 2010 through January 2011). Parameter

Influent (mg/l)

Settling/ Digestion (mg/l)

Anaerobic Lagoon (mg/l)

Sand Filters (mg/l)

Reed Beds (mg/l)

Removal Efficiency

BOD

2,270.4

563.8

312.6

75.6

22.6

99.0%

COD

4,515.4

1,070.4

704.0

172.0

70.2

98.4%

TSS

2,048.0

492.4

354.0

129.0

20.0

99.0%

97.2%

292.0

207.5

170.7

37.9

8.2

NO3-N

2.3

2.4

2.1

13.8

4.4

PO4

25.1

N/A

1.0

TDS

2,003

2,160

2,191

2,107

2,489

4.8 x108

N/A

25.6

N/A

Fecal Coliform (MPN/100ml) Nematodes (eggs/5l)

96.0%

The Shobak WWTP for the treatment of septage uses natural, low-technology treatment provided by the following key process units: septage receiving and screening station; two settling/digestion reactors (each consisting of four 170m2 settling/digestion compartments); two 2,900m2 anaerobic settling lagoons; 10 300m2 intermittent sand filters; four 5,000m2 reed beds; and 30,000m2 of evaporation ponds (see Figure 3). The settling/digestion reactors and anaerobic lagoons were designed for a 5.0 day and 20 day HRT respectively. Five sand filters are dosed once per day at an average rate of 350mm.

Septic hauler unloading at Shobak. One of the most difficult requirements of JS 895/2006 is the nitrate-nitrogen requirement. An initial feasibility study for the SCP identified that sand filters (either intermittent or recirculating), followed by reed beds, offered the most favourable low-maintenance technology capable of providing consistent oxidation of the high-strength ammonia-nitrogen concentrations present in the raw septage. However, in order for the sand filters to operate properly, unit operations were necessary upstream to reduce organic and solids loading rates. Sizing and unit process design of the treatment facilities was based primarily on operational data and operating experience obtained from Drarga, Morocco, with adaptations necessary to accommodate the more concentrated nature of septage and the differing environmental conditions. The primary differences between the

80 DECEMBER 2011 water

two facilities are the capacity (Shobak is designed to handle up to 450m3/d, while North Shouneh is designed for 1,200m3/d), and the local climate conditions (Shobak is designed for a winter average temperature of 6.4Â°C, while North Shouneh is designed for a winter average temperature of 15.8Â°C).

Shobak WWTP The Shobak WWTP is designed to receive an annual average of 350m3/d. The facility has been designed to accept an average of 425m3/d over eight summer months and 200m3/d over four winter months, with the ability to treat high flows of up to 450 m3/d for at least one summer month. Because of the cold winter temperatures encountered in the Shobak region, complete nitrification and denitrification using natural processes to continuously meet JS 895/2006 was deemed uneconomical under design conditions. Therefore, the Shobak WWTP was designed primarily for effluent evaporation.

Although primarily designed for evaporation of the effluent, current treatment is capable of meeting reuse standards during parts of the year, particularly under lower loading rates than design. The facility has also been sited and designed to accommodate upgrade and expansion in the future should it be necessary. The facility started receiving septage in late January 2010 and one treatment train became filled and began completely processing wastewater at the beginning of July 2010. During the first 12 months of operation (February 2010 through January 2011) an average of 164 tankers delivered septage each month for an average influent quantity of 64m3/d. The highest septage quantities were received in June and July (maximum monthly average of 85m3/d). Plant performance data is presented in Table 5. Comparing the effluent quality results presented above against the Jordanian Irrigation Reuse Standards (JS893/2006) shown in Table 4, the average quality of effluents produced by the WWTP is in compliance with Class A. However, some of the samples taken (i.e., maximum values) exceeded Class A limits. All

technical features

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Recirculating sand filters at Drarga. samples taken, however, are within Class B limits. All effluent is currently discharged to the evaporation ponds. However, given the high quality of effluents, the WWTP management has begun looking into potential reuse for irrigating trees planted along the highways instead of using scarce fresh water. Approximately 400m3 of digested sludge has been drained from the settling/digestion reactors since the start of operations. These were then dried on sludge drying beds. Sampling has indicated the dried solids can meet requirements for all field classifications permitted under the Jordanian Bio-solids Reuse and Disposal Standards (JS 1145/2006). As such, it is the intention of the WWTP management to mix the dried sludge with the soils within the WWTP site and utilise it as a soil conditioner for nearby forest trees areas.

North Shouneh WWTP As previously stated, the North Shouneh WWTP is designed for 1,200m3/d of septage. The North Shouneh WWTP is designed to continuously meet JS 893/2006 Class B reuse standards (presented previously in Table 4) and consists of the following unit process: septage receiving and screening station; two settling/anaerobic/denitrification reactors (each consisting of four 240m2 settling/digestion compartments, three 740m2 anaerobic compartments and three 120m2 denitrification compartments); two 3,800m2 facultative lagoons; 12 1,500m2 recirculating sand filters; and two 5,600m2 reed beds (see Figure 4).

Settling/Anaerobic/ Denitrification Reactor

Recirculating Sand Filters

Reed Beds

Effluent Storage Reuse Water for Crop Irrigation

Septage Receiving Facultative Lagoons

Nitrate Recycle

Figure 4. North Shouneh Septage Treatment Plant Process Flow Schematic. The facultative lagoons were designed for a 9.0 day HRT. The sand filters are divided into two trains. The sand filter design is based on an eight-hour work day. During this eight-hour work day, in general no more than two filters per train will be dosed every two hours, with no single filter dosed more than once per day. The maximum recycle rate from the sand filter effluent to the denitrification compartments is 6,000m3/d. The North Shouneh WWTP is currently under construction with completion projected in late 2011. Footnote: This paper is an edited version of a presentation to the IWA Convention at Singapore International Water Week, 4–8 July, 2011.

The Authors Thor Young (email: Thor. Young@ghd.com) is GHD Inc’s Service Line Leader for Wastewater Treatment and Recycling and Rip Copithorn is GHD’s Global Technical Leader for Water, both located in the firm’s Bowie, Maryland, US office. Joseph Karam is the President of Ecodit LLC and is located in the firm’s Arlington, Virginia, US headquarters.

Osama Abu-Rayyan is Ecodit’s Chief of Party for the Jordan Small Communities Project and is based in Aman, Jordan.

References Morocco Ministry of Agriculture: Assessment of the Reuse of Wastewater for Agriculture at the Treatment Station at Ben Sergao, 1996 (published in French). Pollution Control Division, Morocco Office National de l’Eau Potable (ONEP): Quantitative and qualitative assessment of the waste water treatment at Drarga in the Region of Agadir, February 2005 (published in French). United States Agency for International Development: Design Documents for Drarga, Shobak, and North Shouneh WWTPs, 1997 to 1998, and 2005 to 2008 (prepared by Stearns & Wheler/GHD under subcontract to ECODIT and IRG). United States Agency for International Development and the Water Authority of Jordan: Wastewater Treatment Facilities for Small Communities in Jordan: Shobak WWTP Operations, Maintenance, and Training Report No. 1, February 2011 (prepared by ECODIT under subcontract with IRG). United States Environmental Protection Agency: Guidelines for Water Reuse. EPA/625/R-04/108. September 2004.

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microbiology

refereed paper

MOnITOrIng MIcrObIOlOgy WIsely A user’s guide to monitoring program design and collection of exposure data J O’Toole Abstract This paper provides a synopsis of a ‘User’s guide to microbiological program design and collection of exposure data’, one component of a National Water Commission (NWC) fellowship project completed in 2011. While the guide was written to assist in optimising the collection of microbial (pathogen) exposure data, the schema outlined can be adopted more broadly to other types of monitoring. Step-by-step guidance on the planning and design of a water quality monitoring program, including how negotiations with watertesting laboratories may be approached and questions that should be asked by those commissioning testing, is presented in this paper. Effective communication between those commissioning water quality testing and laboratory personnel is a key element in deciding the most appropriate method to be employed for monitoring and, also, in determining how methodological shortfalls and other data gaps might be best addressed through targeted research. The ‘User’s guide to microbiological program design and collection of exposure data’ provides an aid to enhance communication.

and reliability of analytical or instrumental methods; the cost of such methods; regulatory requirements; and the purpose for which monitoring is being undertaken. The steps in planning and designing a microbiological monitoring program, excluding sampling issues, are shown in Figure 1. Of note are the interdependency of multiple steps and the central importance of first carefully defining the purpose for which monitoring is intended (Step 1). In defining the specific question

step 1: Define purpose of monitoring

steps 3 & 4: Select laboratory and engage with personnel with necessary expertise

Design of a water quality monitoring program requires decision-making about many aspects, including: the most suitable micro-organism(s); the method to be employed for testing; the number of samples to be tested; and the monitoring frequency. Such decisions are dependent on the availability, suitability, accuracy

82 DECEMBER 2011 water

Another important step in planning and designing a water quality monitoring program is to consider whether there are existing data that can be used (Step 2) as a substitute for, or as a supplement to, data that are planned to be collected. Where data are available but scrutiny

step 2: Are data available and useful?

If no data are available and/or suitable, new data will have to be collected

Data are available and fit for purpose

Use data to supplement data that are to be collected

Use data as a substitute for data that you had planned to collect

step 5: Obtain information about microorganism best ‘fit for purpose’

Introduction In modelling health risks there are major sources of risk assessment uncertainty that are difficult to estimate directly due to limitations of available data and monitoring procedures. Important data gaps include the prevalence and concentration of pathogens in various water sources. To address such data gaps, monitoring programs must be designed to ensure not only best value for money, but also, fitness for purpose.

to be answered, decision-making about the micro-organism to select for testing (Step 5), the method to be employed (Step 6) and the minimum number of samples required (Step 7) is simplified.

step 6: Select method based on the attributes of available methods

step 7: Determine the number of samples

step 8: Document method operating characteristics and assumptions with collected data

Figure 1. Steps in designing a water quality monitoring program.

technical features

microbiology

refereed paper

shows that data are unsuitable, the designer of the program is forced to consider why such data are unsuitable and how data that are to be collected are best reported (Step 8) to optimise future data sharing and use. While not directly related to the attributes of the monitoring program itself, Steps 3 and 4, which focus on the testing laboratory and communication between the program designer and laboratory personnel, are important in assuring the quality of generated data. Decision making about sampling issues, such as where samples should be collected, sampling technique and sample preservation, are also important but have not been considered as part of the schema outlined.

step 1: Defining the Purpose of Monitoring Microbiological monitoring programs are undertaken for many reasons, ranging from compliance with water quality regulations, where the end product is tested; operational monitoring, where process control is assessed and verified at different points in the water treatment train; and investigative monitoring as part of the risk management process, where treated water and/or source water quality may be assessed. For water quality compliance monitoring, many of the decisions about the monitoring program are pre-determined. For this type of monitoring the analyte is prescribed, as are the frequency of testing and the number of samples per annum per population supplied. Regulations may also require that a particular method is employed for testing and prescribe sampling locations. However, this is not the case for operational monitoring or investigative monitoring programs. For these types of monitoring programs, there is scope in choosing the design. Defining the purpose of monitoring is central to monitoring program design; hence, it is important that it is carefully considered. In some instances a number of monitoring options may be suitable for purpose and the selection of one approach over another may be determined by budgetary constraints or, perhaps, on the basis of standardisation with prior collected data. Careful consideration of the purpose of monitoring may show that the use of a surrogate micro-organism or analyte, rather than monitoring for the microorganism of interest, is both suitable for purpose and affordable. Alternatively, based on the intended purpose of monitoring, investigation may show

that the use of surrogates is inappropriate and there are no data supporting their use, requiring review of the budget amount to allow for monitoring of the target microorganism, assuming that a testing method is available.

step 1: summary • Are program objectives too broad or ambitious? Can project objectives be refined? • Type of data analysis (QMRA, comparative, pass/fail with guideline etc)? • Budget adequacy? • Consider target micro-organism(s)? • Surrogate? • Viability/infectivity/genotyping?

• Information to be recorded for future data sharing? Where the purpose of monitoring is to quantify the risk upon the integrity of the method(s) associated with a particular scenario used for generating data, the or to compare two scenarios, the documentation accompanying aim of the monitoring program should the data about the method used be defined in terms of the planned (e.g. reference to a standard method or, statistical analysis. Where a judgment if a standard method was not employed, is to be made about whether the scenario exact details of the method employed, meets pre-set guideline limits, the including its operating characteristics); acceptance criteria should be specified. the water type tested (e.g. physicoThese additional specifications will ensure chemical properties, catchment type, that appropriate consideration is given pollution inputs, rainfall levels) and, data to method detection limits and to the being made accessible. Data may be appropriate use of enumerative versus available from the scientific literature, qualitative methods. from organisational records (e.g. where prior monitoring programs have been Specification of the type of statistical undertaken) and, increasingly, because analysis to be performed prior to data of electronic data storage capabilities, collection also assists to ensure that from data repositories that have been sufficient samples are analysed or, if this specifically set up for this purpose. is not possible due to budget constraints, that there is a re-consideration of the A search for relevant data in advance budget amount and/or the scope of of conducting a water quality monitoring the monitoring program at the planning program has merit for many reasons. stage. Careful consideration of planned Where suitable data are already available, statistical analysis or pass/fail judgements data may be used as a substitute for, or may show that pilot monitoring is a supplement to, data that are planned required. A pilot monitoring program can to be collected. This allows for a costbe used to determine the likely prevalence effective use of resources. Where data are and levels of micro-organisms in the water available but scrutiny shows that data are type in question, thereby assisting to unsuitable, the designer of the program ensure that in the ‘full’ program, sufficient is forced to consider why such data are numbers of positive samples are collected unsuitable and how data that are to be (and budgeted for) and/or the sensitivity collected are best reported to optimise of the method employed is adequate. future data sharing and use. In addition,

step 2: Are Other Data Available and Useful? Monitoring programs are expensive, hence it is preferable that high quality data are generated which, ideally, can be shared. The usefulness of data for purposes other than for which they were initially collected depends

step 2: summary • Are data available that can be used to substitute/ supplement data to be collected? • If data are able to be used (e.g. as ‘default’ values), what are the assumptions made (if any) about their suitability and is there supporting information to justify any assumptions made? • Does data provide information about the prevalence and/ or levels of micro-organisms in the water type of interest and, thereby, assist in scoping the monitoring program? • Where data are unsuitable, what information is missing? Use this as a prompt to ensure that all necessary information is recorded with results in the execution of this monitoring program.

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step 3: summary

step 4: summary

• Is the laboratory NATA accredited and does the laboratory’s scope of accreditation include those methods and/or micro-organisms of interest?

Is the person with whom discussions are engaged familiar with:

• Can the laboratory provide Measurement Uncertainty (MU) data and/or data about the performance characteristics of the method(s)? perusal of existing data potentially provides information about the likely levels and prevalence of the target microorganisms in the water type of interest, thereby simplifying decision making about the monitoring program and/or obviating the need for a pilot monitoring program to establish these parameters. Prior information about the likely prevalence and levels of micro-organisms in a water source assists in determining the method detection limits and the total number of samples that are required for meaningful data to be obtained. A search for relevant data not only assists in the planning and design of monitoring programs and in improving the quality of documentation of program results (see Step 8), but also gives an awareness of data gaps and focuses attention on research and method development(s) that are required.

step 3: laboratory Attributes and Accreditation Of primary importance to assure the quality of generated data is that the testing laboratory engaged to conduct microbiological testing is one that is technically competent. In Australia, the National Association of Testing Authorities, Australia (NATA) undertakes laboratory accreditations for technical competence. The criteria for determining a facility’s competence are based on the relevant international standard (for water-testing laboratories this is ISO/IEC 17025) and include: the qualifications, training and experience of staff; correct equipment that is properly calibrated and maintained; adequate quality assurance procedures and appropriate sampling practices. In addition, ISO/IEC 17025 requires testing laboratories to have and apply procedures to estimate the uncertainty of their measurements and to communicate such estimates to their customers (ISO/IEC, 2005). Additionally, accredited laboratories are required to participate in interlaboratory proficiency programs for relevant micro-organisms, where available, to support their other quality control activities. While laboratories must meet a minimum standard to become accredited this does not mean that all accredited

84 DECEMBER 2011 water

• Details of available methods? • Validation and verification data that supports the use of non-standard or modified methods offered by the laboratory?

• Quality assurance data held (method sensitivity, recovery laboratories efficiency, detection limits)? are at the same standard. • Latest ‘research’ methods? Accordingly, • Expected levels and prevalence of pathogens in different it is important to water types? base the selection of the testing laboratory upon quality program, it is important that additional criteria as follows: personnel with whom discussion is engaged are not only familiar with the • The laboratory’s scope of accreditation detail of available methods but that (does the laboratory’s scope of they are also familiar with the latest accreditation include the micromethodological advances and alternative organism(s) of interest?) approaches that may be used to meet • In the event that a laboratory offers program objectives. This may, but not a test that is not a standard method, necessarily, require direct contact with does the laboratory have supporting personnel responsible for sample analysis. validation or verification data available step 5: What Micro-organism for perusal? • Has the laboratory estimated the measurement uncertainty (MU) associated with the test result for the method of interest and is this estimate available? • Can the laboratory provide information about the method such as recovery efficiency, method sensitivity, performance of the method using different matrices (e.g. low- versus high-turbidity waters) as well as, or as a substitute for, MU estimates?

should be selected?

The selection of the micro-organism for testing, while dictated by the research question/objective of the water quality monitoring program, also depends on the availability of a suitable analytical method. For example, the study objective may be to monitor the level of viruses in sewage, yet currently there are no suitable cell-culture methods for rotaviruses and noroviruses, which have the highest pathogenicity and are likely to be present in high numbers in human waste.

In commissioning a testing laboratory Accordingly, investigation of viral risk it is important that questions are asked may require that a decision be made to: i) about the availability of MU estimates test for other pathogenic viruses for which for methods of interest, and this is cell-culture methods are available; ii) test particularly important where results are for the target viruses using polymerase being compared to a regulatory standard chain reaction (PCR) methods which or specification limit. With knowledge of detect both viable and non-viable viruses MU, appropriate management step 5: summary strategies can be designed which take • Is there any scope in the selection of micro-organism into proper account to meet monitoring objectives? the potential risk • What choices of micro-organism are offered by the associated with laboratory? Do the methods offered fall under the scope decisions based of (technical) accreditation of the laboratory? on test results. • Are there any standard methods for micro-organism step 4: liaison in question?

with laboratory Personnel

• Can the laboratory provide data to support the use of microbial and/or other surrogates?

In communicating with the testing laboratory when designing a water

• Can the laboratory provide data about the relationship between viable and total numbers of the target micro-organism?

technical features

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or, iii) use an indicator or surrogate for pathogenic viruses (e.g. bacteriophages). On occasions where there are a number of options regarding the micro-organism of choice to meet the objectives of the monitoring program, the selection of test micro-organism will depend not only on the cost of analysis but also on the supporting scientific evidence (e.g. documented relationship between levels of indicator(s) and target virus) and the operating characteristics of the methods (e.g. recovery efficiency, false positives/ negatives, reproducibility, whether viable viruses only are detected etc). In circumstances where there are budgetary and/or other reasons for the choice of a surrogate micro-organism or analyte rather than the ‘true’ target of the monitoring program, all assumptions used in decision-making should be documented and supporting evidence (e.g. references to scientific papers and/or to results of prior monitoring programs) should be retained to assist future users of data. This is important to contextualise the monitoring program and results in terms of knowledge existing at the time for both future users of data and designers of monitoring programs. Where the budget amount is insufficient for the monitoring of the preferred target micro-organism and there is no evidence to support the use of an alternative, the budget and/or scope of monitoring should be reviewed.

step 6: What Methods are Available and ‘Fit for Purpose’? Having selected the microorganism for testing, the next step is to determine which of the available methods (where more than one is offered) to employ. Where multiple methods are available, a standard method should be preferentially employed. In using a standard method, the operating characteristics of the method are more likely to be detailed; its access (documentation) to a wide

step 6: summary

number of laboratories is assured and data sharing via a data repository or other mechanism is promoted. From a laboratory accreditation perspective, standard methods for microbiology are accepted from recognised standard writing bodies, from compendia and pharmacopoeia texts, and method validation bodies such as the Association of Analytical Chemists. When used without modification, minimum verification to assure the proficiency of laboratory staff in the execution of the method is required for these methods to be accredited. Non-standard methods (e.g. methods developed for research purposes), and standard methods that have been modified or are used for testing outside of their validated scope (e.g. used for biosolid instead of water samples), must be fully validated, including statistical analysis of results in order for these methods to be accredited (NATA, 2009). In those instances where an accredited laboratory offers testing using methods that are outside the scope of their accreditation, the laboratory is required nonetheless to implement practices which ensure the integrity of reported results. Accordingly, where the objective of a monitoring program requires different method sensitivity to that of the standard method and/or where changes to the standard method are made, the laboratory should be able to inform the customer about the contribution that additional steps and/or modifications have on the final reported result (e.g. change in detection limits). Similarly for research methods, the laboratory should have undertaken relevant seeding experiments, performed relevant staff training and, in the performance of the method itself, incorporated relevant quality controls to allow the customer to be provided with information about the detection limit of the method and the recovery efficiency of the target microorganism in different matrix types (e.g. turbid versus nonturbid waters).

• Is a standard method available? • If no standard method is available are there available research methods that may be employed? • Does the laboratory have validation/verification data to support the use of the proposed method? • Can the laboratory provide information about the operating characteristics of the method (recovery efficiency, method sensitivity, MU etc)? • Are there any method recovery datasets for my matrix? • What is the consistency of performance of the method?

On those occasions (e.g. waterborne disease outbreak or special investigations) where it is imperative to monitor for a specific micro-organism, despite there being no standard method available for its detection/ enumeration, a newly developed

and experimental method may need to be employed. In such circumstances, the suite of controls must cover the key elements of the methodology known or suspected to be problematic. For example, PCR virus (RNA) methods should incorporate process controls; a negative RNA extraction control; positive RT-PCR and RT-PCR inhibition controls and negative and positive PCR controls. In the design of a monitoring program, adequate provision must be made for the collection of method recovery efficiency datasets. The recovery dataset should be both adequate (enough samples) and relevant (recovery data should be available for the water type of interest). Questioning about the availability of recovery efficiency data for a proposed method is important. Where datasets are unavailable, discussion should follow about the the way in which a recovery efficiency dataset, relevant to the water location/ type in question, will be collected.

step 7: Determining the number of samples Where statistical analysis of output data is to be performed, awareness of the minimum required sample numbers prior to commencing a water quality monitoring program will ensure that sufficient samples are analysed or, if this is not possible due to budget constraints, will allow for reconsideration of the budget amount and/or the scope of the monitoring program. In some instances determination of the minimum number of samples may require preliminary (pilot) monitoring to scope the levels of target micro-organisms and/or their prevalence prior to a ‘full’ monitoring program being conducted. For example, where the purpose of monitoring is to construct a probability density function (pdf) of the level of a specific pathogen in a particular water type, pilot monitoring can ascertain the proportion of samples where test results are expected to be at, or below, the method detection limit. With this knowledge the minimum number of samples to construct a pdf can be calculated and budgeted for. In addition, consideration can be given to modifying the method so that the proportion of samples with pathogens at, or below, the detection limit is reduced. Where the purpose of monitoring is to assess compliance with a guideline value, the minimum number of samples required to assess compliance will depend upon the prevalence of the microorganism in the water type being tested. The lower the prevalence of the target organisms, the greater is the number of samples required.

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step 7: summary

step 8: summary

• What type of data analysis is planned (e.g. use in stochastic or deterministic modelling; pass/fail determination; comparative analysis)?

Record the following aspects of the monitoring program:

• Where complex analysis is to be performed, consult a statistician for advice. • Can categorical data be employed or is continuous variable data required? • Is a pilot monitoring program required to obtain information about the likely prevalence and/or levels of the target micro-organism? • Determine minimum number of samples required. • Is the budget sufficient to allow for the monitoring of an adequate number of samples? If not, review the budget and/or scope of monitoring program. Where the levels of micro-organisms in different water types are being compared, the minimum number of samples required depends upon the variation in microbial levels in each water type or location. Recognising that this is the case in advance of conducting a monitoring program is important and allows for consideration of a two-stage monitoring program. Using such an approach, investigation of temporal variation in water quality for each water type or location would precede the main monitoring program designed to quantify differences in microbial water quality between different water types/ sample locations. In this way, some planned monitoring programs may be revealed as overly ambitious based on the high variability in the parameters of interest, requiring reconsideration of the program objectives and budget amounts.

step 8: reporting Data The usefulness of data is extended by the way it is reported. It is important that not only details of the method(s) employed are recorded (including operating characteristics such as recovery efficiency, method sensitivity, measurement uncertainty, equivalent sample volume analysed, etc) but that any assumptions made in designing the program are detailed. It is also important that characteristics of the water type are recorded (e.g. physicochemical properties, etc) together with details about pollution inputs and the conditions under which sampling was undertaken (e.g. high-risk versus low-risk pollution events), where relevant. As budgetary constraints, lack of available methods for the micro-organism of interest, method shortfalls (e.g. in terms of sensitivity and/or inability to distinguish between viable and non-viable organisms)

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• Purpose (including the context of data collection (e.g. absence of any data; limitations in existing data etc). • Method characteristics, including operating characteristics, sample volume analysed. • Assumptions made in the selection of micro-organism(s), method(s), sample numbers, sampling frequency. • Characteristics of water type being tested, pollution inputs, climatic conditions etc. • Raw data and not just final results; this includes raw counts in combination with the equivalent volume analysed and recovery efficiency data. Retain supporting evidence where applicable (e.g. reference to scientific literature and/or existing monitoring or pilot study data upon which monitoring program may be based).

and/or limited data about the relationship between surrogates and target microorganisms may all constitute reasons for compromises in monitoring program design, it is important that the rationale behind decisions are documented. This information is important to current and future users of data generated from the monitoring program (so that they can understand data limitations and the context), and to those seeking to address methodological shortfalls through targeted research. Proper reporting of data is also important if data are to be ‘admitted’ to a data repository, as some data repositories may have minimum data reporting requirements.

conclusion Water quality monitoring programs present multiple dilemmas for those charged with their design and implementation, especially in current times when economic imperatives can assume a primary role in deliberations. Compromises are inevitably required when designing water quality monitoring programs; however, it is important that the principle of generating high-quality data influences decision making, as does fitness for purpose. In addition, effective communication between those commissioning water quality testing and laboratory personnel is a key element in deciding the most appropriate method to be employed for monitoring and, also, in determining how methodological shortfalls and other data gaps might be best addressed through targeted research. The ‘User’s guide to microbiological program design and collection of exposure data’ provides an aid to enhance communication.

The Author Dr Joanne O’Toole (email: joanne.otoole@ monash.edu) has over 20 years’ experience as a microbiologist and consultant for government and private industry organisations. She has experience in laboratory management and accreditation and has represented government and water industry bodies on Australian Standards committees. She was awarded her PhD in 2009 and a National Water Commission Fellowship in 2010. She currently holds an NHMRC Training Fellowship at the Melbourne School of Land and Environment, University of Melbourne. She also undertakes research at the Infectious Diseases Epidemiology Unit at Monash University.

Acknowledgements This research was funded by the National Water Commission. Case studies highlighting dilemmas that may be encountered by water quality managers, consulting engineers and health regulators in monitoring program design using ‘real world’ examples are contained in the full NWC report which can be accessed from the NWC website (Waterlines Report #50).

references ISO/IEC (2005): ISO/IEC 17025. General requirements for the competence of testing and calibration laboratories. Geneva, International Organization for Standardization. NATA (2009): Biological Testing. Supplementary requirements for accreditation. ISO/IEC 17025 Field Application Document. NATA.

technical features

contaminants of concern

WATER REUSE: REMOVAL OF TRACE ORGANIC COMPOUNDS A comprehensive review shows that no single treatment can remove all micropollutants B Bolto, M Hoang Abstract The recycling of wastewater and stormwater is often cited as a viable alternative to seawater desalination. However, many undesirable organic compounds have been detected in waterways that receive wastewater effluents used as drinking water sources. The effects of ingestion of low levels of these compounds are not known. At present, no single treatment can remove all trace organic micropollutants. The various approaches are reviewed. Optimal treatment depends very much on the specific micropollutants present in the original wastewater. More needs to be done on the prediction of membrane treatment efficiency where the classes of compounds most likely to be rejected can be defined.

Introduction There are often calls for alternative options to desalination, such as the recycling of wastewater and stormwater, to receive more attention (Kaempf, 2011; Khan, 2011; Malawaraarachchi et al., 2011). Unfortunately, many undesirable biologically active organic compounds have been detected in waterways that receive wastewater effluents and are used as drinking water sources, via indirect potable reuse (Asano et al., 2007; Ying and Kookana, 2007; Wakelin et al., 2008; Schäfer et al., 2011). The effect of ingestion of low levels of these compounds is not clear, but they represent known or suspected health effects for consumers and the environment and are, therefore, of increasing concern. Certainly they have reproductive impacts on animals (Eertmans et al., 2003), two examples being the feminising of fish and the declining fertility of young alligators (Nghiem and Schäfer, 2002; Snyder et al., 2006; Kimura et al., 2009; Yangali-Quintanilla et al., 2009). The compounds occur at bioactive concentrations in the ng/L and low µg/L range (Kolpin et al., 2002) and include: • Endocrine disruptors;

• Pharmaceutically active compounds from human and animal use; • Insecticides and herbicides; • Personal care products (surfactants, chelating agents); • Illicit drugs (Zuccato et al., 2008). A study has been carried out in South Wales in the UK on wastewater plants utilising two different wastewater treatment technologies – activated sludge and trickling filter beds (KasprzykHordern et al., 2009). The impact of treated wastewater on the quality of receiving waters has also been assessed, and bioactive compounds found to be present at high loads, reaching 10kg per day in the raw sewage. The efficiency of their removal was found to be strongly dependent on the technology used. Thus, a trickling filter plant resulted in less than 70% removal of the compounds, while activated sludge treatment gave a much higher removal efficiency of over 85%. A monitoring program revealed that treated wastewater effluents were the main contributors to bioactive compounds in rivers, at up to 3kg per day. As the effluents were major contributors to river flows, with dilution factors not exceeding 23, the effect of the effluent on the quality of the river water was significant.

reviewed (Asano et al., 2007). The present article summarises the various techniques available and gives more details of the most recent advances, with a particular emphasis on membrane methods.

Conventional Treatment A recent evaluation has been made of the removal of pharmaceuticals, including psychiatric drugs, angiotensin agents, antihistamines, β-blockers, other cardiac drugs and EDCs after various treatments at a full-scale drinking water treatment plant (Huerta-Fontela et al., 2011). The plant used raw water from the Llobregat River in Spain, which had total organic carbon (TOC) levels ranging from 2.7 to 10 mg/L over the four months of the study. The treatment steps were: • Break-point chlorination; • Coagulant (Al2[SO4]3, AlCl3, Al2O3) and flocculant (poly-DADMAC) addition; • Sand filtration; • 6–29% dilution with groundwater; • Ozone; • Granular activated carbon (GAC) filtration; • Post-chlorination to a residual of 0.8–1.2 mg/L chlorine.

Australian studies on the removal of pharmaceutically active compounds in sewage treatment plants using different biological processes have been quite extensive (Ying and Kookana, 2007; Ying et al., 2008, 2009; Holmes et al., 2010; Liu et al., 2011). The concentrations of endocrine-disrupting compounds (EDCs) in sewage plant effluents were similar to those reported in international surveys, at high ng/L to low µg/L. The decay of EDCs in groundwaters has also been examined (Ying et al., 2008).

Coagulation, flocculation and sand filtration gave poor removal, but the oxidation processes were better, taking out 20 of the 35 compounds studied. GAC was effective in adsorbing very hydrophobic material, so that overall 30 of the compounds could be removed to 99.7% efficiency from original amounts of above 4 mg/L. Nevertheless, five compounds were detected at trace levels in the finished water: phenytoin, atenolol, sotalol, hydrochlorothiazide and carbamazepine epoxide.

Conventional treatment of river and other source waters when they are the feed for municipal water treatment installations is not particularly successful in removing these micropollutants. The area of removal of trace contaminants by a whole range of technologies has been extensively

Ozone and Ozone-Hydrogen Peroxide The use of ozone as a method for removing trace contaminants has been reviewed (Asano et al., 2007) and surveyed at pilot plant level,

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contaminants of concern where 50–98% could be eliminated (Ternes et al., 2003). Advanced oxidation methods (O3/H2O2, O3/UV) slightly increased removals in some cases. Thus the removal of iopamidol was raised from 57% to 80% with the addition of peroxide when the ozone dose was 10 mg/L, and from 84% to 88% with UV when the ozone dose was 15 mg/L. It was recommended that an economic assessment be carried out before fullscale implementation, bearing in mind that an added advantage is the inactivation of microorganisms. The kinetics and product formation of the anti-epileptic drug carbamazepine during reactions with ozone have been investigated (McDowell et al., 2005). This compound passes through sewage treatment plants essentially unchanged and in Germany can be found in many rivers and waterways at levels averaging 250 ng/L. It was discovered that ozone reacts rapidly with the double bond in carbamazepine. Rhine River water when spiked with 500 ng/L carbamazepine was found to have the additive completely oxidised by ozone doses of 0.3 mg/L. Similar results were obtained for spiked Lake Zurich water. The ozone oxidation of EDCs and pharmaceuticals has been the topic of a recent study (Snyder et al., 2006). Ozone reacts with organic contaminants by either the direct action of O3 or free radicals that are formed, especially the hydroxyl radical

OH. Molecular O3 reacts quickly with amines, phenols and the double bonds in aliphatic compounds, but the .OH radical is faster and less selective. Surface water was spiked with the target compounds, which included estrogenic and androgenic steroids, pharmaceuticals, pesticides and industrial chemicals. Full-scale water treatment plants were sampled before and after ozonation to determine if bench- and pilot-scale results could accurately predict removal in real-life systems. The majority of contaminants were more than 90% removed at O3 levels commonly used for disinfection. Atrazine, iopromide, meprobamate and tris-chloroethylphosphate were the most recalcitrant, with removals generally less than 50%. The addition of H2O2 for advanced oxidation was of little benefit compared to O3 alone. However, the combination provided a marginal increase in the removal of dilantin, diazepam, iopromide and meprobamate, but decreased the removal efficacy of pentoxifylline, caffeine, testosterone, progesterone, and androstenedione.

all trace organic micropollutants to below the detection limit. Other methods of enhancing the production of .OH radicals include sonochemistry, which is effective as a way of increasing the generation of .OH radicals to degrade recalcitrant organic compounds (Pang et al., 2011).

In wastewater experiments, O3 and O3/H2O2 were shown to remove estrogenicity to below the detection limit. It was concluded that, overall, ozone is a highly effective oxidant for removing the majority of trace organic contaminants. Challenging compounds will require greater doses of these or other oxidants. No single oxidant can remove

Specific Adsorbents

Table 1. Predicted and experimental rejection of micropollutants in NF (Verliefde et al., 2007). Micropollutant

Log Kow

Molecular Weight

17β-Estradiol

4.01

272

High, then moderate/high

85-100

Predicted Rejection

Found Rejection, %

Hormones Estrone

3.13

270

High, then moderate/high

0-60, 85-100

Progesterone

3.87

314

High, then moderate/high

90-100

Testosterone

3.32

288

High, then moderate/high

80-100

Industrial chemicals Bisphenol A

3.3

228

High, then moderate/high

70-100, 45

Ultraviolet Radiation-Hydrogen Peroxide An advanced oxidation process in the form of ultraviolet radiation-hydrogen peroxide (UV-HP) has been used as a way of treating source waters containing natural organic matter (NOM) contaminated with a typical synthetic organic chemical and EDC in the form of the pesticide alachlor (Song et al., 2008). Alachlor was chosen as a model compound because of its hydrophobicity and its tendency to complex with NOM. It was discovered that although its decomposition was significantly hindered by the presence of NOM, the process was effective in destroying alachlor in NOM-containing waters because of the high reactivity of the hydroxyl radical with alachlor.

A novel method of selective extraction of micropollutants uses an artificial molecular receptor specifically designed for the target molecules (Le Noir et al., 2007). The polymer particles were made from 4-vinylpyridine cross-linked with ethylene glycol dimethacrylate, which were polymerised around 17β-estradiol as the template. Treatment of a 2 ng/L solution of 17β-estradiol gave 100 ± 0.6% removal, versus 77.3 ± 3.7% when the polymer particles were made in the absence of a template, which shows the potential of the method. Lower removals were achieved with GAC. The adsorbent could be regenerated with solvent, methanol in this case. The progress of research on various polymers such as porous particles and imprinted polymer particles as adsorbents for EDCs has been reviewed recently (Suna et al., 2011).

p-Dimethylphthalate

2.2

194

High, then moderate/low

65-80

Membrane Processes

p-Diethylphthalate

3.2

222

High, then moderate

65-80

Nonylphenol

4.4

220

High, then moderate

70-90

Nanofiltration

MTBE

0.9

Moderate

89.6

Atrazine

2.6

216

High, then moderate

26-99

Simazine

2.1

202

High, then moderate

17-96

Chlorpyrifos

5.2

350

High

>99

Pesticides

Pharmaceuticals Primidone

0.9

218

Moderate/high

72-87

Carbamazepine

2.4

236

High, then moderate/high

Ibuprofen

3.9

206

High

70-95

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Nanofiltration (NF) technology for trace contaminant removal has been reviewed comprehensively (Nghiem and Schäfer, 2005; Hofman et al., 2006). While size exclusion can be responsible for separation, several studies have shown that even large molecules such as EDCs can pass through some membranes (Kiso et al., 2000, 2001). An adsorption diffusion mechanism can occur. This has been broken down into physical selectivity: charge repulsion, size exclusion or steric hindrance; and chemical selectivity:

technical features

contaminants of concern solvation energy, hydrophobic interaction or hydrogen bonding. Thus membranes may adsorb estrone, which will result in an initially high retention. Hydrogen bonding has been postulated as the mechanism of adsorption of this compound (Nghiem and Schäfer, 2002). If the pore size of the membranes is larger than the estrone molecules, breakthrough may be observed when the adsorptive sites are saturated. In all, eight different NF membranes or the tighter reverse osmosis (RO) membranes were tested; the RO membranes had much smaller pore sizes that could not be penetrated by estrone. No breakthrough was observed with these membranes. A review of mechanisms for estrogens has recently been published (Schäfer et al., 2011). The rejection of trace organic compounds by a variety of NF membranes under a range of experimental conditions has been reviewed in an extensive report that covers 20 scientific papers (Hofman et al., 2006). Results for approximately 120 different compounds of various types, not just EDCs and pharmaceuticals, were assessed for 30 different membrane types, resulting in a data base containing more than 1,000 rejection measurements. A statistical analysis showed that 60% of the rejections were above 80%. It was concluded that hydrodynamics play an important role in the rejection performance of spiral wound membranes. Also, that convective transport through the NF membranes was important, and that on the full scale rejections can drop significantly at high recoveries of above 80%. A model was developed that can be used for the design of full-scale plants. Some particular findings were: • Rejections of small neutral organic compounds such as alcohols and sugars correlated well with molecular weight (MW), with the transition from low to high rejection occurring near the MW cut-off of the membrane at ~200 Da; • Rejections of more polar or partly dissociated small organic acids also show a good correlation with MW, but with the transition occurring below the MW cut off; • Rejection is influenced by the adsorption of organic compounds, which may take 3 or 4 days to reach equilibrium before a stable rejection takes place. Some compounds such as alkyl phenols have a high affinity for the membrane so that they are completely adsorbed;

• Phenyl urea herbicides were a special case in that with methoxy methyl urea groups there is a decrease in rejection when the MW is increased. While NF is successful in removing larger pollutants, it is claimed that it can also tackle smaller hydrophilic and/ or charged organic micropollutants (Verliefde et al., 2007). Because of the polar nature of some micropollutants such as nitrosodimethylamine (NDMA) and methyl tert-butyl ether (MTBE), they are not completely removed by conventional water treatment, including GAC. Qualitative prediction of NF rejection has been achieved by using several solute parameters, such as log Kow (the octanolwater partition coefficient), pKa and molar mass (although it is molecular size that is the issue) to predict removal efficiency. Polarity is important, as solutes with a high dipole moment may align in the direction of the pores of the membrane because of electrostatic interactions with the membrane charge. This causes the solutes to permeate more easily, so they have a lower rejection. Polarity can also be a function of hydrophobicity, and hydrophobic interactions between solute and membrane can result in adsorption of the compounds on the membrane surface and in the pores. The higher the hydrophobicity of a compound, expressed by log Kow, the greater the likelihood of adsorption on the membrane. This can result in a higher initial rejection. Solution of the solute in the membrane and diffusion through the membrane are also contributors to transport mechanisms. The more a compound adsorbs onto the membrane, the easier it will dissolve in

the membrane, to be transported to the other side. A higher log Kow should thus lead to a lower rejection. Rejection will obviously also be affected by the size of the solute molecule, and can be explained as a steric hindrance phenomenon. This applies to hydrophilic compounds as they are expected to be more hydrated, increasing the effective size of the molecule, so that there is better rejection than for non-hydrated species. The relative influence of hydrophobicity is, hence, more important than molecular mass in determining rejection in NF. Comparison with experimental data in the literature confirmed that the set of parameters used is adequate to give a rough estimate of the likely removal efficiency. Some 17 compounds were surveyed in this way, the details being shown in Table 1. Membrane pore data are as provided by the membrane manufacturer. The many references for the experimental values, resulting in some cases in several sets of results for the one compound, are given in the original paper (Verliefde et al., 2007). The predicted rejection of MTBE is moderate, and the found value is 89.6%. The prediction for NDMA is the same, but there are no experimental data to date. Information on pKa, the dissociation constant of micropollutants, is not always available; Table 2 summarises what is known. One investigation of the contribution of electrostatic interactions to the rejection of selected organic acids by NF membranes has shown that the rejection of negatively charged carboxylic acids was larger than expected from steric exclusion and was primarily driven

Table 2. Predicted and experimental rejection of micropollutants in NF as a function of pKa (Verliefde et al., 2007; Bellona and Drewes, 2005; Albert and Serjeant, 1962). Micropollutant Nonylphenol

pKa

Charge at pH 7