Water Journal September 2004

AWA AUSTRALIAN WATER ASSOCIATION

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Volume 31 No 6 September 2004 Journal of the Australian Water Assoc iation

Editorial Board F R Bishop, Chairman B N Anderson, G Finke, G Finlayson, GA Holder, B Labza, M Muncisov, P Nadebaum, J D Parker, F Roddick, G Ryan, S Gray, A Gibson, P Masse \. Water is a refereed journal. This symbol indicares chat a paper has been refereed.

Submissions Instructions fo r authors can be found on page 8 of this journal. Submissions accepted at: www.awa.asn .au/publications/

OPINION 2

AWA is Alive and Well; Sustainability Comes to the Fore; My Point of View, Making Waves: Water Challenges in the 21st Century, P Cullen

ASSOCIATION ACTIVITIES 12

AWA's Education Program Begins

MEMBERS' FORUM

Managing Editor

14

Peter Stirling

PROFESSIONAL DEVELOPMENT

Technical Editor

16

E A (Bob) Swinton 4 Pleasant View Cres, Wheelers Hill Vic 3150 Tel/Fax (03) 9560 4752 Email: bswimon@bigpond .ner.au

News Editor

Water Production Hallmark Editions PO Box 84, H ampton, Vic 3188 Level I, 99 Bay Street, Brighron, Vic 3186 Tel (03) 9530 8900 Fax (03) 9530 89 I I Email: hallmark@halledir.com.au Graphic design: Mitzi Mann

Water Advertising National Sales Manager: Brian Rault Tel (03) 9530 8900 Fax (03) 9530 89 I I Mobile 0411 354 050 Email: braulr@haHedir.com.au

Water (ISSN 0310 - 0367)

Details of courses, classes and other upcoming water events

CROSSCURRENT 20

Industry news

CONFERENCE REPORTS 28

Clare Porter Communications Manager Tel +61294 13 1288 Fax: (02) 9413 1047 Email: cporrer@awa.asn.au

New Special Interest Group, K Harries

World Water Week & the Stockholm Water Symposium, Ian Jarman, AWA; 2004 Stockholm Water Prize

FEATURE: BENCHMARKING 30

THE ART AND SCIENCE OF BENCHMARKING It can make a difference for the future, for both developed and emerging nations S Berg

33

AN INTERNATIONAL BENCHMARKING NETWORK FOR WATER AND SANITATION Statistics for a thousand utilities in over thirty countries at a mouse-click S Ramsey

36

INPUT BENCHMARKING OF ASSET MANAGEMENT PROCESSES Benchmarking past performance is backward-looking, aim for "best appropriate practice" R Byrne, D Hope

42

BENCHMARKING AND REGULATION - ADVANTAGES AND CONFLICTS Internal and external benchmark studies are incompatible A Seipolr

is published eight rimes a year in the monrhs of February, March, May, June, August, September, November and December.

HISTORICAL

Australian Water Association

44

PO Box 388, Arrarmon, NSW 1570 Tel +6 1 29413 1288 Fax: (02) 94 13 1047 Email: info@awa.asn.au

AWA

ABN 78 096 035 773

President Rod Lehmann

Chief Executive Officer

~

Acknowledging the role of four Australian engineers in the 1950s H F Akers, S A T Porter

FEATURE: SLUDGE DRYING 50

WATER

56

Visit the Australian Water Association

61

and occess news, colendors, bookshop and over 100 pages of information at

http://www.awa.asn.au

•, DRUM DRYING: PILOT TRIALS ON SYDNEY WATER SLUDGES Trials on various sludges, using a pilot-scale direct-fired drum dryer B Windschuttel, Q Tran

WATER TREATMENT 64

OPERATION AND MAINTENANCE OF BAC FILTERS FOR OPTIMUM PERFORMANCE What to do and not to do to operate BAC P T hiel, P Cullum

WATER BUSINESS 66

HOME PAGE

•, 'SOLARMIX' - CONTINUOUS BIOSOLIDS DRYING The first 'SolarMix' facility on Queensland's Sunshine Coast works well S Nathan, B Clarke, N Byres

Subscriptions Water is sent to all AWA members eight times a year. It is also available via subscription.

•, STABILISATION OF BIOSOLIDS USING THE AGITATED AIR DRYING PROCESS Machinery windrows a blend of dewatered sludge and finished product RE Desmier, C Liston, L M Sickerdick

AusrRAL IAN

Chris Davis ASSOCIATION Australian Water Association (A WA) assumes no responsibility for opinions or statements of fucts expressed by contributors or advertisers. Editorials do not necessarily represent official AWA policy.

Advertisements are included as an information service to readers and are reviewed before publication to ensure relevance to the water environment and objectives of A\YIA. All material in \Vater is copyright and should nor be reproduced wholly or in part without written permission.

.,_ WATER FLUORIDATION: THE ENGINEERS' CONTRIBUTION

NEW PRODUCTS AND BUSINESS INFORMATION

OUR COVER: The winning photograph ofthe Australian Water Partnership Photographic Competition, thanks to Stuart Quinn ofSouth Australia. Stuart submitted his photograph under the topic of'Ecosystems - Wetlands' and called it 'Reeds'.

from the president

AWA IS ALIVE AND WELL 1 had the good fortune ro attend a number of major AWA events last month ; August is the month in which rhe Branches h ave their AGMs and, in several cases, annual dinners. There were over 300 people in attendance at the Brisbane Gala Dinner and 180 at Townsville's Annual D inner. Vicroria continued ro set the pace, with a huge 500 people attending its Annual D inner in Melbourne.

I n NSW, I was able to attend part of the Annual "Heads of Water" seminar titled Who Needs Water. At each event I was overwhelmed by the enthusiasm of the participan ts and the individual "spin " (dare I use that word) put on each function by the Branch.

Ar the Brisbane Gala Dinner the speaker was the Hon Stephen Robertson, who is M inister fo r Natural Resources and Mines. H e addressed the issue of the high urban growth in South East Queensland and the water supply shortfalls on the Gold Coast and emphasised that the Government will be raking a much stronger role in gu iding urban growth and water supply plan ning. Minister Robertson also commented that the focus on national water reforms has tended to be on the Murray-Darling system, at the expense of other major river systems such as the Burdekin - a sentiment that has been

In Melbourne th e Deputy Premier and Minister for Water, the Hon John Thwaites, outlined some of the initiatives emerging from Vicroria's famous White Paper, notably: rising block tari ffs to discourage excessive consumption; a levy on water charges ro cover the cost of externalities; a suite of permanent restrictions on wasteful water use; and facilitated water trading.

Additionally, Vicroria now has a Safe Water Act, which places responsibility squarely on water suppliers to im plement best practice management strategies.

The Dinner was a grand event and networking went on t ill people had to be shovelled our of the room in the early hours.

At the NSW "H eads of Water" cocktail function we

People come to learn about what is happening and what is new and I am sure they genuinely want to help to make things work better in the future. expressed by a number of people.

At the Townsville.Annual D inner we were treated ro a well-prepared and invigorating debate about engineers and their merits. As usual, the engineers got bagged, but being an engineer myself, I know we can carry the burden. It was highly entertaining and made fo r a fun night.

2 SEPTEMBER 2004

water

were created to short d issertations from Federal Shadow Minister fo r Environment, Kelvin Thomson, Parliamentary Secretary ro the Minister for Natural Resources, Alison Megarrity, NSW Shadow Minister for Natural Resources (S tate) Andrew Stoner, Shadow Minister for Environment Michael Richardson and Deputy Lord Mayor for the C ity of Sydney John Mclnerny. Ms

Megarrity noted NSW Government plans for a new Cabinet sub-committee to address Sydney's long term water needs and noted that the Government was proposing a new Innovation Council.

Ar the "Who Needs Water" seminar the follow ing day, the critical water problems facing Sydney were highlighted. Carole H owe from CSIRO provided some preliminary resu lts of modelling looking at different demand and water recycling assu mptions as well as climate change impacts. There are significant shortfalls down the track. Peter Sutherland, Depu ty Director General for the Office of Coastal, Rural and Regional NSW provided some background ro the strategic planning that the Government was doing in relation to the future water su pply requirements for Syd ney.

Unfortu nately he was unable ro reveal any specifi c derails at this stage, but I look forward to hearing more abou t this in future.

The fina l event that I attended was the WA Branch min i symposium in Kalgoorlie.

The extreme cold weather did little to dampen the enthusiasm and warmth of the delegates.

The symposium dealt with many of the current issues fac ing Western Australia including the shortage of water ro meet current and future needs and the difficulty of supplying water ro remote communities. Kalgoorlie is such an example with a 565 km pipeline constructed back in 1903 to supply water from the Mundaring Weir ro Kalgoorl ie.

Over the years this has been progressively upgraded and water has also been sourced from a borefield to provide an additional securi ty of supply.

More recently the Water Corporation has moved forward with plans to b uild a 45GL/a seawater desalination plant.

Peter Moore from the Water Corporation gave derails of this $350111 project (including the

associated infrastructure) wh ich will supply water into an integrated water supply system that feeds Perth and the Goldfields. D r Jim Gill, the CEO for the Water Corporation noted that Western Australia had always been innovative in dealing with water and as an example cited the 0.5 ML/d "mammoth" water condenser which was built at Coolgardie near Kalgoorlie, in 1896, ro supply fres h water fo r the mining community. The condenser was fue lled by local timber, consuming abour 800 tons of wood per day.

Jim also noted that the general approach th at has been adopted by the Water Corporation involves supply from a diversity of sources together with initiatives with catchment management, water trading and water efficiency improvement.

As I commented above, the exciting part of being part of AWA is the people you meet and en thusiasm of the members everywhere. Each Branch has its own cul ture, dictated by the local people and the structure of the water industry in that state or rerrirory, but each adds valu e to the water business in its area.

People come to learn about what is hap pening and what is new and I am su re they genuinely want to help to make things work better in the futu re.

A WA is indeed alive and well.

Rod Lehmann

water

FUTURE MAJOR FEATURES NOVEMBER - Memb rane App lic ations in Water and Wastewater incl Alternat ive Treatment Systems DECEMBER - Simulation and Modelling FEBRUARY - Tr enc h less Technology, Coastal CRC, Water Efficiency MARCH - Sustainabi l ity , Wastewater Treatment, Odour Control

AWA AUSTRALIAN WATER ASSOCIATION

When & Where:

Thursday 21 October 2004 SA - The Vines Golf Club, Reynella VIC - Heidelberg Golf Course, Lower Plenty QLD - Redland Bay Golf Club, Redland Bay

Friday 22 October 2004 NSW - Sydney: Beverley Park Golf Club, Beverley Park, Kogarah - Northern NSW: Wauchope Country Club, Wauchope NT - Darwin Golf Club, North Lakes WA-Tuart Course, Wembley Golf Complex, Floreat

Activity:

18 Holes of Golf Teams of four - individuals encouraged Shotgun Start - Playing 4-ball Ambrose

Project:

Funds raised will go towards a schools sanitation project in Papua New Guinea. The project aims to create lasting improvements in the health and hygiene behaviour plus the sanitation facilities for teachers and children in 14 community schools. The project will directly benefit approximately 3,500 students and indirectly 13,300 community members in the Eastern Highlands Province of PNG.

Cost:

From as little as $30 to $125 per player. This includes green fees, food (generally BBQ) and presentation ceremony.

Interested?

RSVP to your local golf committee coordinator. Contact details and registration forms are available from www.awa.asn.au/events/golfday Or Clare Porter cporter@awa.asn.au Ph: 02 9495 9916

With thanks to our National Sponsors :

VinicJe'x Syste ms & Solution s

ECOWISE ENVIRINMENTAL

Exciting accommodation package prizes offered by: Leve l 2, 44 Hampden Road PO Box 388, Artarmon N SW 1570 Te l: (02) 94 13 1288 Fax: (02) 94 13 1047 Email: info@awa.asn.au We b: www.awa.asn.au ABN 78 096 035 773

p

AccoR

benchmarking

THE ART AND SCIENCE OF BENCHMARKING S Berg Why Benchmark?

Infrastructure is in need of rehabilitation in many developed coun tries. In emerging countries, water has come co symbolize the huge gaps between promise and performance. The sad cru ch is chat the political economy of water is such chat those who make tough decisions will nor receive credit during their terms in office.

Nevertheless, benchmarking represents an important cool for documenting past performance, establishing baselines fo r gaugi ng improvements, and making compariso ns across service providers.

The Audiences T here are at least six audiences for yardstick comparisons.

First, benchmarking specialists produce and critique studies that utilize various methodologies. Currently, quantitative comparisons utilize four methodologies: sophisticated average coses and productivity indicato rs, linear regression analyses, Dara Envelopment Analysis (DEA, using rtonparamecric cost frontiers) and rhe economic/engineering analyses ("model company" or "virtual fi rm" method) . Data reliability and comparability affect the validity of all fou r approaches, and rankings can be manipulated by choice of variables and model specification. Implementing policy means making judgement calls, and technical experts may not possess the skills required co negotiate agreements regarding how the rankings are co be used. Thus, chose preparing studies muse realize chat they are writing for multiple audiences with a variety of needs.

This article is a much shortened version of th e keynote address to rhe Conference "Global Developments in Water Industry Performance Benchmarking", Perth, September, 2003. The ocher three papers in chis feature on benchmarking are updated versions of presentations to that conference, which featured some rhirry international authors. Conference Convenor, John Hannan, john.hannan@lenvironmen t. wa.gov.au, has developed and published a CD/DVD package of the conference proceedings including all available papers, Powerpoint presentations, speaker videos and ocher valuable info rmation.

Available at cost of$150 from C hris Nabi at the Office of Water Policy in Perth Western Australia, ch ris.nabi@environmenr.wa.gov.au

30 SEPTEMBER 2004

water

Second, che press fi lters and highlights reports, using "sound bites", executive summaries, and interviews.

Unfortunately technical reporcs are not amenable co sound bites. Nevertheless, reputable reporters and journalises seek a clear message from a benchmarking study.

Unfortunately some reporters seek sensational factoids co support their personal ideologies; ochers may lack the expertise co interpret technical studies. The problem of communicating complexity and rhe tentative nature of a thorough benchmarking report's conclusions places a special burden on chose preparing the report fo r public scrutiny. The executive summary muse focus on the implications of the study and emphasize rhe limitations of the analysis.

information for policy makers. However, seccor performance also depends on efficient price signals, benefits from quality improvements, recognitio n of any transition costs, incorporation of environmental impacts, and meeting social obligations.

• Pricing efficiency: Race design can result in usage prices cracking marginal costs, with fixed coses recovered by (monthly) service charges. H owever, a short-run price signal chat is efficient is nor necessarily sustainable. A complete benchmarking analysis should address pricing issues, and oucline a framework for incorporating rare desjgn inco performance evaluation.

• Service quality: C learly outputs of different quality need co be treated

There are at least six audiences for yardstick comparisons, each with different needs. Even so, relative and absolute rankings can become catalysts for better stewardship of water and other resources, both for developed and emerging nations.

Third: The general public (and opinion leaders) cry to understand the implications of rankings for their evaluation of sector performance, but they are heavily influenced by what they read and hear in the news media.

This suggests chat long before releasing a benchmark comparison, the agency should be engagi ng in an information campaign, informing political leaders and the public about rhe purpose of rhe forth coming report.

The agency must choose between releasing one large study, where the news scories are likely co focus on the most sensational elements (for headlines), or a series of studies where the cumulative effect may be an info rmed citizenry. However, there is chen a risk chat the im pace may be diluted by the pressure of ocher events. The best strategy is not clear.

Fourth, che regulator reviews studies and creates performance incentives co achieve policy objectives.

Productivity advance and ocher measures of technical efficiency provide valuable

differently. A level of quality which is not valued highly should not necessarily generate an overall high score for the utility. DEA is useful in incorporating multiple outputs, including q uality. In UK the Overall Performance Assessment cakes account of chis element.

• T ransition coses: Care muse be taken when a company has been restructured.

Noc only is this disruptive to management but it often brings to light past inefficiencies or under-fu nding which have to be corrected by the new authority.

• Environ men tal impacts: Simple inputoutput comparisons which ignore externalities will impose future costs, just as accounting ledgers will not capture the consequences of deferred maintenance or equipment replacement.

• Social obligations: Different jurisdictions will have different social obligations, eg. various combinations of urban and rural populations, population density, mandatory service to low-income, even non-paying, customers. These issues muse be add ressed in conducting a comparison study.

benchmarking Fifth: National policymakers (elected representatives and appointed officials) react to and utilize technical studies in setting priorities and interacting with international organizations. Domestic political leaders are confronted with rankings that can indicate that the system is not meeting expectations.

Solid data provides an antidote to government opportu nism and the politicization of water p ricing. Those making promises will at so me point be held accountable.

One might ask why benchmarking studies have not been significant tools in most countries over the past four decades.

One answer is chat the politicians did not really want the information. T he resulting financial crises experienced by many water utilities have led to increasing private sector participation and multilateral fun d ing initiatives. When industry oversight responsibility is assigned to well-trained regulatory professionals, the resultan t studies can truly make a d iffe rence to public attitudes.

Sixth, Water utility managers are sensitive to comparisons. Ir is extremely d ifficult for an outsider to evaluate the performance of managers (only insiders know whether they being managed well or poorly); therefore

-~~ -~

TRIAGE FOR AID? "The tragedy is that aid programs and multilateral organizations were slow to utilize benchmarking in the 1970s and 1980s for a rational triage approach to funding infrastructure investments. The resource misallocation and corruption that accompanied much of the Cold War inspired aid is a sad reflection on the priorities ofthe developed nations. A strong argument can be made that the weakest performing systems should NOT be given aid, and that high performing systems should be rewarded. This conclusion seems heartless, yet unless tough fonding decisions are made, incentives are quite perverse. Those nations and utility systems making correct decisions deserve to be rewarded. In circumstances where lives are at risk (the poorest ofthe poor), emergency measures are certainly warranted.

However, one can argue that this aid should not involve significant untargeted outlays, but only short-term (targeted) funds. First, civil society must develop the institutions, political consensus, and the critical mass ofexpertise required to create sustainable organizations.

Capital-intensive projects might be least-cost in principle, but are likely to result in delays and waste that dissipate most ofthe potential benefits from such aid. I wish I knew how to manage this terrible problem: for now, I can only point out that the historical record is not one that gives me much confidence. " Sanford Berg, 2003 poor utility managers may delay or block serious benchmarking. H owever, it is in the interest of good managers co promote comparisons which can enhance their careers.

Note chat it is costly to produce information unless it is a by-product of ongoing management processes. One can ask why such information for some countries is so inadequate. Some responsibility is due to government ministries and international

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fund ing agencies which are happy to cut ribbons at grand openings; rhe difficult (and far less glamorous) day-to-day operatio ns do not lend themselves to public ceremonies.

Conclusion Although each of these six groups has d ifferent needs, relative and absolute rankings can become catalysts for better stewardship of water and ocher resources.

The art and science of yardstick co mparisons requires both techn ical expertise and experience. I am convinced more than ever char benchmarking is one of the tools chat can make a difference for the future, both for developed and emerging nations.

The Author Sanford Berg is D irector of Water Studies, Public Utility Research Center of che University of Florida, www.purc.org. In addition to research, the Center provides training in utility regulation and strategy, with some 1,300 participants to dare from 123 countries.

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water

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benchmarking services in a sustainable manner, and ultimately co achieve M illennium Development Goals.

IBNET Such problems are cop of the agenda b oth for the UK's Department for I nternacional Development (DFID) and the World Bank, ch rough its Water and Sanitation Program. Between them they have fund ed and launched the Internacio nal Benchmarking Network fo r Water and Sani tation Utili ties, known as IBNET. Building on the d evelopment and success of the World Bank Benchmarking Scarr Up Ki e, a pilot system co facil itate the compilation and sharing of water and sani tation performa nce data at the national, regional and international level, IBNET is being developed co provide an effi cient and effective m echanism for ben chmarking as a route co the develop ment of improved performance throughout the sector.

IBNET provides a unique web-based n etwork of natio nal databases covering the performan ce of water and sani ration u tilities throughou t the world. In face it is already the world's single largest water sector d atabase, providing access co cost and perfor m ance data from over four hundred utilities in twen ty countries.

Over the n ext few months alone ch is wi ll grow co nearly one thousa nd utili ties in over thirty countries.

The characteristic of water and sanitation as a local service often means char individual utilities do not have easy access co comparable performance information in o rder co judge how well their performance and practice com pare with ochers, even within their own country . Such essential information, based on com parative data, gives water utility managers, and chose charged with regulatory or oversigh t responsibilities, rhe opporcuniry co know how well utilities are perform ing in the real world. The information also allows an opportun ity co set targets for improvem ent, and to access knowled ge on b est practices in ocher utilities chat will su ppor t improvement p rogrammes.

Benchmarking at a natio nal level is an important first seep, providing the com parative data char is the basis for a miliry co understand its current performance per se and by comparison with its peers, o perating in comparable circumstances, and p roviding a m eans for the setting of improvement targets for the future. By providing a mechanism whereby many national bench marking schem es are d eveloped and linked in a

34 SEPTEMBER 2004

water

common framewo rk , IBN ET widens the benchmarking horizon , allowing any utili ty co com pare its performance internationally and co access the wealth of data and knowledge available in the sector wo rldwide.

IBNET is designed co meet the needs of ocher stakeholders in the water industry coo , governments and public bodies, the regulatory authorities, funding bodies including commercial fun ders, development institutions and fundin g agencies, and indeed customers. These stakeholders can use comparative data co assess current performance, co focus fundin g and developmental supp ort, co set targets for performance and co monicor progress . Perhaps most imporran cly, as a source of standardised and comparable data and informatio n, it can provide a common basis fo r informed policy d ebate, and facil itate dialogue between donors, government and ocher stakeholders.

The Next Phase In October 2003 World Bank, with supporting fundi ng from DFID , contracted WRc pie of the UK, co lead the next phase of development, until 2005. The key casks, during chis period, are co expand the coverage and effectiveness of the existing benchmarking network, co include m ore utilities with a wid er geographic spread; specifically co encompass both rhe information needs of utili ties in developed and in d evelop ing countries, and co address the needs and objectives of the fu ll range of anticipated stakeholders. In order co meet these potentially con fli cting objectives, the curren t p erformance indicacor list is being refined and supplemented where necessary or app ropriate. In particular, it is important co address the often very basic issues affecting utilities in developing countries, and a range of poverty related

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indicators is being developed and reseed for inclusion.

Most crucially, the period of contract is the window co identify and build sustainable long term operational, managem ent and financial arrangements for IBNET. This tri ple challenge encompasses securing sustainable data inpu t and p erfor mance indicator generation , and thereby securing th e operational purpose of IBNET; identification of an appropriate and accep table managem ent struccure, co ensure the dynam ic leadership and development of IBNET, and the identification of an appropriate management body, acceptable co the range of stakeholders, an issue alread y being addressed; and lastly, co secure ongoing fi nancial security.

Ir is clear chat many schemes fai l, despite the real o r potential finan cial benefits co participants, because of an inability co identify long term fun ding.

Problems can arise from both an inability co pay fo r the service and indeed fro m an unwillingness co pay. C areful consideration is b eing given , therefore, with a range of p roject stakeholders, co the possible options fo r the ongoing fun d ing of IBNET, including commercial ch argi ng, commercial funding and support fina ncing for some part of the service offered. Financial arrangements muse b e in place at the end of the current contract period.

How does IBNET deliver?

IBNET represents a key opportunity co provide both a means and a sec of cools co enable water and sanitat ion u tili ties co develop national or regional groupings for the purpose of undertaking regular benchmarking activi ties. In addition IBNET will actively suppo rt the d evelopment of comparative performa nce schemes at the local or national level.

H owever it must also be a central purpose of IBNET co provide the opportunity for these local or n ational benchmarking initiatives co undertake international comparisons. IBNET provides easy co use software for data collection, performance indicator calculation and dataset presentation, and will p rovide easy access co comparable international perfo rmance d ata.

T he key challenge is the development of a system which will meet the benchmarking requirements of all water utilities and national benchmarking schemes, whether fro m developing or developed countries, as well as balancing the requirem ents of the ocher stakeholders

benchmarking in rhe sector. This challenge needs co be mer by having a coherent purpose and , fo llowing ex tensive marker research with many practitioners of benchmarking schemes from all pans of the world, IBNET will have, at its core, featu res that will promote good ben_chmarking practice among water and sanitation services worldwide: • Providi ng guidance on indicacors, defi nitions and methods of collecting data. As far as practicable a standard sec of indicacors and standard indicacor defi nitions will be used throughout, removi ng two of rhe key comparabili ty obstacles which many benchmarking efforrs face.

• Providi ng guidan ce and support on setting up national or regional benchmarking schemes.

• Holding and giving access to a pool of water utili ty performance data in the publ ic domai n.

• Providing rhe infrastructure ro undertake peer group perfor mance data companso ns.

• Li nking people wirh co mmon interests and common problems, and thereby

promoting rhe sharing of best practice amongst utili ties.

T he means by which these will be del ivered will be through rhe IBNET website, whi ch represents the most important and central aspect of IBN ET. Nor only wi ll users of !BNET be provided with the largest database on worldwide water and sanitation performance data, indicacors and information bur th ey will also benefit from a key range of oth er services: • An easy co enter and easy co access facili ty fo r getting hold of perfo rm ance data from other benchmarking schemes avai lable on the web sire.

• Easy access, search and down-loadable facili ties co the benchmarking database, and advice on ind icacor defini tions and experience from other benchmarking schemes.

• Access co a full knowledge resource on benchmarki ng and co mparative data analysis in che water and sani tation seccor.

• Facilities to find benchmarking partners and set up networks fo r benchmarking.

• A multi language capability.

Benchmarking ar a local , national and inrernarional level can help all water and sanitation uriliries, whatever their developmental srarus, to measure their performance and identify thei r shortcomings, find comparacors fo r identi fyi ng and sharing best practice, and new knowledge and co drive performance improvement. Th e aim is always co ensure th at nothing is missed in the important job of delivering rhe best services fo r custo mers.

IBNET has a key role co play as a benchmarki ng facili racor, both for the sharing of best practice between water and sa nitation utili ties across the world and for providing rhe information fo r all those working in the seccor, be they fund ing agencies, consultants, academics and most im portantly the water and sani tation utility managers. Readers can access the latest draft at http://www.ib-ner.org/ newlook/hcml/index.hcm

The Author Stephen Ramsey is Direccor of WRc Ucili cies, Swindon, W iltshire, UK. Email: ramsey_s@wrcplc. co.uk.

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benchmarking

INPUT BENCHMARKING OF ASSET MANAGEMENT PROCESSES R Byrne, D Hope Abstract This paper examines some of the reasons why ongoi ng changes have been required in the ap proach to Asset Management over rhe last quarter cen cury. I t describes an ISO based quality technique developed by G HD which allows uriliries to develop a continuous improvement app roach to asset management processes which is fl exible and follows business needs as driven by changed circumstances. I mprovements and performance can be moni tored indefinitely.

By imp rovin g all quality elements in a balanced scorecard approach, large sums of money can be saved through better decision making on new cap ital, operations, mainten ance and renewals expendicure, and risks can be considerably reduced .

Australia's water utilities currenrly manage a diverse p ortfolio of assets worth well over $50 billion between rhem .

Introduction Increasing expectations from governments, regulato rs, customers and the general community, combined with everimproving technology, means that utilities must embrace programs of contin uous improvement ro keep pace.

In particular, the Hillmer report in 1993, carried ou t for the Counci l of Australian Governmen ts, led to the adoption of the National Compet ition Po licy. T his policy has led co w idespread reform o f u tilities, and a drive for efficiency and performance.

Assets are the key to success in any public infrastruccure provider, and rhe major cost d river. The successful management of assets is a complex b usiness, involving the working together of hundreds o f quite different p rocesses, with sometimes competing deman ds and priorities. T he traditional approach of measuring and benchmarking past performance is a backward looking exercise, concen trating on previous accom plishments and underperformance. It does noc provide any real gu idance as ro the capability of the o rganisation to adapt ro fucure business drivers and meet fu cure challenges.

Assets are also effectively monopolies, given their long life, and high co st to duplicate for a com petitor. I mprovements in the performance of the existing assets,

36 SEPTEMBER 2004

water

and the delivery of future assets is largely in th e hands of the asset managers, who are more easily ch anged rhan rhe assets if performance is unsatisfactory.

The changing approach to asset management The app roach to Asset Management as a discipline began to change rapidly during rhe 1980s as a result of a number of influences. Concerns began to arise abour lon g-term viabili ty issues within all public uti lities wh ich had signifi ca nt stocks of ageing assets, and also within governments.

Long-term fo recasts of renewals costs, based on nominal asset lives, began to be undertaken. T hese forecasts starkly d emonscraced che need for grearly increased expenditu res in future years whi ch would require huge tariff increases to sustai n.

There were also co ncerns that ageing pipe netwo rks may p roduce crisis-level performance fa ilures if quantum changes were not made.

The older and larger utilities, with their greater need and greater resources, have generally led che way in developing processes fo r more holistic asset management, and by the 199 0s, comprehensive asset man agement plans were being produced. This was a period wh en che paper-based systems of previous generations began ro be replaced wich developing IT systems. T he new technology included asset database systems, fi nancial management systems, capital planning

With the fai rly rapid changes in IT capability, and with the benefit of growing experience, new trends in Asset Management are continuing to emerge, and processes are changing. The larger utilities are moving away from the concept of chick paper-based asset management or system management plans, updated ar discrete periods such as ann ually.

Some utilities are adopting what amounts to a strategic framework, which encapsulates the main aspects of plann ing, analysis and decision making processes, linked directly to the organisation's business d rivers, and assessed short and lo ng term risks. Below rhis level, assets are d ivided into classes or sub-classes, so char general app roaches to decision making can be formulated and revi ewed with the guidance of the strategic framework.

T he engine room fo r carrying out che majority of asset management processes has beco me the new generation IT systems.

T hese systems have rapidly developed capability since the early days, and the ability to provide seamless links b etween systems is now much better.

T ools such as co mputerised mainten ance management and geographical in formation systems are now being used in tandem to record information about each asset, including maintenance h isto ry and cost, co sched ule maintenan ce p rograms, and co provide data fo r an alysis. T he term "virtual

The purpose ofprocess benchmarking is not to control but to review and improve the processes and practices and the allocation of resources. systems, mainten ance management systems, geographical information syscems(GIS), asset mo ni toring and control technology (SCADA), and various analysis tools. New tech niques were also being developed and cried , aimed at improving and optimising maintenance and renewals p rocesses, assessing the conditio n of assets, selecting better capital options, identifyi ng and managing risks, improving informat ion systems, improving d ata and knowledge, managing organisational and people issues, and better targeting effort to priorities.

asset management" is sometimes used to d escribe the concept of managing assets through the data management and decision process capability of modern, linked IT systems. T he cost and effort of b uilding, operating and maintaining these systems is, nonetheless, considerable. Unfortunately, it can be totally wasted if the o rganisatio nal culture and processes are not bedded d own in a fu lly sustainable manner.

As a result of the factors mentioned above, Strategic, or Total, Asset

benchmarking Management Plann ing has become a discipline, and there are a range of guidelines available on this topic. In som e places, rhe following of these guidelines has been made mandatory by governments.

In addition to the growing awareness of asset issues in utilities, rhe community began demanding higher standards of perform ance in areas such as costs, the environment, drin king water quali ty, provision of new services, and more lately in ensuri ng suffi cient quantities of water are available. T he community also began to expect service providers across rhe spectrum to improve their performance by the ongoing adoption of new technology and smarter methods.

Changes in approach by governments as a result of the National Competition Policy to issues such as competition , effic iency of government owned monopolies, return on investment, dividends, privatisation, outso urcing, perfo rmance and regulation have also had considerable inA uence.

Australian water utilities have been measured on past performance for so me years agai nst benchmarks as a result of reform ro competition policy and legislation.

In relatively recent times, regulators have arri ved on the scene, as surrogates fo r the government and the co mmu ni ty. They have begun looking ar ways to provide confidence to governments relating to long-term asset management performance and viabili ty, as has already been do ne in relation to an nual performance. Amongst the reaso ns fo r chis interest by rhe regulators is occasio nal major failures in utilities in va rious places around the world, and concerns rhar shore-term efficiency drives by management may result in long-term problems.

Th ere have been a number of examples of failures arou nd rhe wo rld. Close to home, an ea rly problem arose in NSW in rhe 1970s, where the conti nuous supply of electricity had been seriously threatened by poor management and workforce practices.

These practices resu lted in poor maintenance performance and overin vestment in expensive generating plant. In rhe water industry in the early 1980s, borh rhe water and sewerage services in the Blue Mountains in NSW had deteriorated to such an extent char Sydney Water was required to rake over the assets and the operatio ns. Syd ney Water delivered the expertise to construct an emergency water

supply scheme, and ro carry our a comp lete reva mp of the sewerage system. T he extensive wo rks were well beyond the resources of rhe local council and were benevolently funded by Sydney Water customers, under di rection from rhe NSW government. There have been a numbe r of examples of "sudden", bu t long brewing, failures, or near misses around rhe world since.

Regulators ini ti ally used output benchmarking as rhe cool co drive efficiency across all agencies. H owever, normalising such benchmarks is very difficult and most regulators are now looking to the next stage.

Th is involves also assessing and recognising rhe quali ty with which each agency is managing their asset portfo lios from a lo n g term sustainability perspective. T his approach ensures that both efficiency and effectiveness, rhe key success facto rs of alI good in vestment decision making, are taken into account.

Asset management is a complex set of in terrelated acri viries, ranging from rhe strategic ro rhe tactical, and involving hund reds of processes and sub-processes . No organisation has rhe resources co reach "world 's besr practice" in each and every one

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SEPTEMBER 2004 37

benchmarking of these processes, and any attempt to do so may actually reduce performance by reducin g the focus on the most important issues - the problem of "not being able to see the wood for the trees".

Asset management contains some elements which could be described as science, whilst others are still in the art or experienced judgement arena. However, with all the R&D being undertaken, we are moving closer to science, and away from

an.

A set of meth odologies, based around the benchmarki ng of inputs, is d escribed below.

These methodologies, implemented with the h elp, where needed, of experienced independent people, provides a fi rm basis for ongoing strategic review of the efficacy and business focus of asset management efforts. Input benchmarking tools and approaches have also been developed by other organisations, such as the Water Services Association of Australia.

The use of such an effective ongoing process does not, in itself, mean that an organisation will be successful. But it goes a long way in providing management, regulators, governments and other stakeholders with a level of confidence in the utility's long term asset management capability. T h e process also has the advantage that it better in forms utility staff of the priority of processes, and the impact of these processes on the overall performance.

In addition to benchmarking, governments and regulators have also used ocher techniques, such as audits of Asset Management Plans and p rescription of asset management approaches through government guidelines or rules.

There is no definitive roadmap to best p ractice, or best appropriate practice, and there will always be a number o f different paths which can be followed to provide successful results.

Input or Process Benchmarking Methodology GHD has been involved in developi ng Asset Management methodologies and tools for over two d ecades, including an approach to p rocess benchmarking and the implementation of process improvements.

T his methodology is described below ro illustrate what can be done. As noted above, there are a number of other approaches available.

T h e main aims of this approach are to: • provide a tool to measure the fu ll set of relevant processes against world 's best practice within a comprehensive quality framework;

38 SEPTEMBER 2004

water

• provide a methodology to determine the "best appropriate practice" (BAP) when measured against the specific business and risk drivers or priorities of each individual enterprise, i.e. the business case for why they need to be that good; • provide a methodology to determine achievable an d justifiable process improvement targets, based on areas of highest business priority, or most cost effective/ easiest gains; • provide a methodology to co nstruct and implement process improvement projects to meet improvement targets; • p rovide a meth odology for monitoring process improvements, and regularly reviewing the strategy against changing business performance and needs or against new opportunities p rovided by new techniques or technologies .

Process benchmarking involves comparison with best practice performers through " input" processes and practices. By putting processes under the microscope through the range of act ivities from the strategic to the tactical, this form of benchmarking tries to set a business up for the future by: • Doing the right things - being effective through ongoing adjustments to what is done, based on changing business drivers and,

• Doing things right - being efficient through che implementation of appropriate processes and technologies.

The purpose of process benchmarking is not to control but to review and improve che processes and practices and the allocation of resources in order to enhance rhe productivity, the effectiveness and efficiency of an organisation.

An important element of ben ch marking is to realise those elements being benchmarked may or may nor be best practice or best appropriate practice for the organ isation in its current environ ment.

Experienced benchmark facil itators are required to determine if the current "result" is ap propriate or whether change is desirable. Simp le benchmarking may reveal a number of organisations all doing the same thing, but are they doing it well or are they all doing it poorly?

Through benchmarking, the organisation is exposed to opportunities to move forward from dared work practices in some instances, bur in any case to an ongoing situation of responsiveness covering areas such as: existing or forecast customer and stakeholder needs; staff development and job satisfaction; asset performance and maintenance; and rhe satisfaction of overall corporate goals.

O rganisations often tend to look for similar types of organisations to bench mark against. Although this makes sense in the first instance it can lead to more of che same, and result in just incremental improvements in performance.

Benchmarking with unlike organisations chat have some similar or common processes rends to occur less often, but is potentially the more ferti le ground for bringing radical performance improvement into the organisation. All infrast ructure asset managers suffer the same drivers (required level of services at th e lowest life cycle cost) but they can all potentially develop innovative ways to overcome these.

TEAMQF The TEAMQF or 'Total Enterprise Asset Management Quality Framework' methodology is described below. It is a quality fram ework that has been d eveloped over several years to assess the ab ility of infrastructure or property rich service delivery organisatio ns to manage their built assets from a whole of busi ness perspective.

Any such framework must con tinuously evolve to meet the demands of business and to reflect the current b est practices. Such a framework should include: • setting a future vision for asset management and relating this to the business; • a 'Gap Analysis' comparing current practice to th is future vision or best appropriate practice model; • prioritisation of gaps identified above based on the organisation's business drivers or "Business Value C hain"; and • an Improvement program that translates these gaps into clear action plans with tasks, resources and riming that is economically justified from a proven benefit/cost b asis while meeti ng the short and long term business drivers.

Understanding the Gaps and their Value to the Business The 'Value Chain' is a management con cept embraced by many major corporations throughout the world. The Value C hain is made up of those key organisational processes chat must be managed if the organisation is to thrive. In other words it rep resents the priority that each core life cycle Asset Management process co ntributes to the success of the business.

When we understand rhe Gap that exists in our quality elements and the priority or benefit they represent then we can identify rhe things that each organisation should do first. I r prioritises rhe improvement program.

benchmarking The Quality Framework fo r an asset intensive organisation usi ng this methodology is generally made up of 7 primary quality elements, 23 secondary elements and 173 tertiary quality elements in this exa mple. Figure 1 depicts a typical utility business value chain showing the seven prim ary asset management elements which are: • Process and Practices used in the co mpletion of life cycle asset management activiries for Best Appropriate Practice sustainable Asset Management, set to sui t each organisation.

• Information Systems that are requi red to support the processes and practices, and store and manipulate the data and knowledge as required.

• Data and Knowledge of the assets and asset performance, their appropriareness, adeq uateness and reliability.

• Commercial Tactics used to efficiently carry out the work identified by the processes above.

• Organisational Issues co mprisi ng the structu re, roles and responsibili ties that ex ist to support life cycle asset management.

• People Issues comprisi ng the attitudes, skills and endeavour of staff involved in the Asset Management process.

• Asset Management Plans, which fo rm the key outputs from the above inputs and processes.

T hese seve n primary elements are critical to achieving sustained perfo rm ance of the organisation at the lowest life cycle cost.

Each of the seven components 'adds val ue'

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I ~ UFECYCLEAM PROCESSES & PRACTICES

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Figure 1. Typica l Utility Busi ness Value Cha in.

to th e raw busi ness processes consistent with regulations, customer demands and shareholder requirements. For chis reason, these seven components are termed the primary 'Value Chain'.

All activities undertaken by a utility business should contribute to its value in terms of delivery. Each activity wi ll be linked and form com ponent pans of the business Value Chain. Each activity will have a level of importance or weight measured by its contribu rion to the Value Chain.

Sim ilarly, delivery of 'best value' service can be assessed through use of the Asset Ma nagement Value Chai n.

Asset Management Value Chain Successfully managing thi s Value Chain leads to achieving the Asset Management mission and goals of the organisation.

Each orga nisation has a unique sense of the relative importance of the Asset Management Val ue Chain quality elements because of their business, environmental, and social/cultural setting. By quanti fying this relative im portance through a relative weighting, the gap analysis yields the right balance of quality elements and compo nen t improvements.

Value C hain weightings can be varied for businesses at di fferent phases of their path to susta inable Asset Management. A common Value C hain fo r long term sustainable Asset Management has been developed, and this is used as a common benchmark Value Chain between mility businesses. This is how the world's best practice models and the priority of rhe improvement programs are adjusted to suit each individual business.

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SEPTEMBER 2004 39

benchmarking Primary Quality Element : Processes and Practices Secondarv Quality Eleme nts

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Figure 2. G ap Aud it Tool - Illustrative "Scorecard", showing just the first p rimary elem ent out of the seven, and associated secondary elements.

Other sho rter-term business drivers from which Value Chain weightings have been derived include: • business efficiency; • growth o r compliance capital; • renewals; • regulatory and pricing; • retailers' p rojects and strategies.

More than one Value Chain can be developed to show the relative impact of changes and test sensitivity of results. The audit process provides for the appropriate business drivers to be identified, and each primary and secondary quality element in the gap analysis to be weigh ted accord ing to its Value C hain contribu tion. T he process is collaborative and can be modified at any stage of the process.

What is the "Gap Analysis"?

T he gap analysis allows an organ isation to understand where it is relative co where it wants to be in terms of the quality of Asset Management practices. The gap is the d istance between the current and the desired future state of the organisation.

I t allows an organisation to compare itself to those Asset Management practices that are considered reasonable and relevant for that particular organisation to embrace.

This is not necessarily 'World's Best

40 SEPTEMBER 2004

water

Practice', which may not be appropriate fo r the specifi c organisation due to factors such as its commercial objectives, its geo graphic spread, its asset profile, its regulatory environment, and its urban or rural base, co name so me. T he important thing is co identify 'Best Appropriate Practices' (BAP) - those practices that fit the o rganisation's needs in the most effective and effi cient way.

T he gap analysis serves four obj ectives. It: • assesses Asset Management processes, practices and systems against Best Appropriate Practice fo r an organisation; • identifies processes where the organisation has achieved excellence i. e.

Best Appropriate Practice; • identifies processes where the o rganisation requires improvement, guiding future action toward and measu ring progress against Best Appropriate (or reasonable) Practice; and • allows p rogress and the level of performance to be measured indefinitely.

What is the "Gap Audit Tool"?

The gap audit tool provides an interface for compiling all the information gathered , analysing and presenting it in a fa miliar and simpli.fied environment. An example of part of the resulting "Sco recard" is shown on Figure 2.

The columns in the full gap matrix, when extended to the tertiary level, rep resent each of the 173 Asset Management quality elements that comprise over 150 0 best practices associated with advanced Asset M anagement.

The rows of the gap analysis chart map progressive levels o f Asset Management p ractice - from "innocence" upward th rough "awareness" and "competence" co "excellence." Each level up the scale represents, as appropriate, better practices, data, information, organisation, and knowledge abou t the d ecisions being made.

The scale is somewhat like a 'log' scale, i.e., the effort required for an organisatio n to step from O to 50 is considerably less than to go from 50 co 100. T h is is consistent with the belief that early gains can be achieved relatively cheaply, but that considerably greater effort/cost is required co derive benefits as an organisation approaches optimum performance.

At the bottom of the gap analysis chart are several rows of numbers representing the confidence level assigned to each column (or quality element) in the chart.

A clear and documented rating scale is needed so that the utility can easily revisit the gap analysis over time and redefine their scores and relate this to current business drivers as they may have changed. This

serves two purposes, it allows progress to be clearly shown in implementing im provements plus it allows th e redefini tion of the furnre tasks and the order in which they should be addressed.

Assessment Process T he assessment process adopted usually includes workshops and interviews with key utility staff, and reviews of documents and processes. T he level of Reviews can be undertaken as a simple self assessment of a limited num ber of processes. At the other end of the scale, an advanced audit is an extensive review that in volves training, workshops, and greater partnerin g and facilitatio n to develop improvement programmes that are focussed on delivering results in li ne with strategic business plan goals and objectives.

Conclusions Expectations on the perfo rmance of water utilities have increased quite appreciably since the 1980s. These expectati ons cover diverse areas such as pricing and costs, drinking water quality, the environm ent, and increas ingly the quantity of water available.

Natio nal Competition Policy has caused major changes since coming inro being in the mid- l 990s.

Assets represent the key cost drivers and risk areas for utilities, and are a considerable management challenge. Assets are generally longlived, and are effectively a monopoly in themselves. The managers of the assets are more easily changed, and managers must look to continuous and competent improvement to retain the trust of the commun ity. Governments have appointed regulators as surrogates to watch the performance of the utiliti es, their efficiency and the cost of sustainable service delivery. The regulators are increasingly rnming their attention to long term asset sustain ability issues.

Asset Management is the sum of literally hundreds of subprocesses. Success depends on the right level of performance in each of these sub-processes, and in the sum , or total effect, of the parts.

Measuring success is quite complex: the business drivers vary from organisation to organisation, and wirh time fo r each organisation; asset circumstances and technology vary; and the art and science of asset management is evolving. T here is not always unanimous agreement on what constitutes "best practice" - in any case, there is usually a range of different ways to "skin the cat", or to get a good result. Experi enced asset managem ent practitioners are therefore needed to ensure the best outcomes.

Input benchmarking can provide a well defin ed and structured view of the quality of processes against best practice. T he prime purpose of using the methodologies is to continuously improve performance and capability in line with business drivers.

The discipline of input benchmarking, with the associated improvement program methodologies, is seen as a central plank in ensuring chat future risks are managed, opportunities taken and efforts optimised.

Acknowledgments The approach and processes outlined above have been steadily developed over C\venty years at GHD under the guidance of Roger Byrne. Contributors to this body of work are too numerous to list here, but the contribu tion of them all is freely acknowledged.

The Authors Roger Byrne is the In ternational Asset Management Manager currently based at GHD's Los Angeles Office (email: Roger_Byrne@ghd.com.au). David Hope is Principal Consul tant, Asset Management in G HD's Sydney Office (email: David_Hope@ghd. co m. au)

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SEPTEMBER 2004 41

benchmarking

BENCHMARKING AND REGULATION ADVANTAGES AND CONFLICTS A Seipolt I have spen t the better (or some would say worse) part of my career in the utility benchmarking field. I have personally constructed, undertaken and reviewed benchmark studies across electricity, gas and water utilit ies throughout much of the developed world.

My two contentions based on this experience, are: a) internal and external benchmark stud ies are incompatib le; and a) benchmarking, for setting utility prices. should be an input process and not an output process

Abstract The two principal applications of benchmarking as it relates to water businesses are: 1. Those benchmarks undertaken by the water businesses (e.g. for internal and business improvements).

2 . T hose benchmarks undertaken on the water businesses. (e.g. for external regulatory, stakeholder, owner and cons umer purposes.)

My two contentions for chis paper, based on experience, are: a) internal and external benchmark stud ies are incompatible; and b) benchmarking, for setting utility prices, should be an input process and not an output process.

Internal Benchmarking

World's Second Oldest Profession Benchmarking may be the world's second oldest profession, but is often considered as far less reputable than the fi rst.

I magine, if you will, an early caveman seeking to choose between two similar caves ...

• What was the primary decision facto r?

- Position, position or position?

- Was it the light and ventilation or the proximity to fresh food?

- Cold and cold running water?

• What was the measurement base used?

• How were the criteria evaluated?

I am not enough of an anthropologist to be able to tell yo u if benchmarking is something that d iscriminates us from animals, but it is certainly a common fearure amongst homo sapiens.

Now that we have established chat benchmarking has been around for a long time, let's look at how it relates to today's

Benchmarking to improve your own levels of efficiency and performance should be kept well separated from benchmarking for regulators, shareholders and owners.

However, I sho uldn't be too quick to belittle benchmarking. Everyone is a benchmarker. If we pick up two cans of soup in the supermarket and make a decision on one over the other we have just conducted a benchmark. Each of us undertakes multiple comparative reviews every day; what to make fo r dinner, how to travel to work, what casks to complete at work, etc.

42 SEPTEMBER 2004

water

environment. The two principal ap plications of benchmarking as it relates to water businesses are: 1. T hose benchmarks undertaken by the water businesses (e.g. for internal and business improvements.), and 2. T hose benchmarks undertaken on the water businesses. (e.g. for external regulatory, stakeholder, owner and customer purposes.)

Internal benchmarking is benchmarking for the company, by the company. In other words, its purpose is to improve the business perfo rmance by comparing against other like companies, processes or systems.

Benchmarking has a proven history of allowing companies to look outside of their business and see what are the options for internal business improvement? Where can the management most effectively expend their energies? What can be improved now and what can be improved later?

A good benchmarking program will not o nly identify where a company is in relation to its peers. A good benchmarking program will also provide: • the value of the improvement opportunity to the business in terms of both cost and service levels (even TripleBottom Line); • identification of the underlying facto rs impeding improvement; • costs and time-frames involved in achieving the potential improvement; • prioritisation of improvement opportunities; • provide momentum for the internal "selling" of the need for improvement.

At the end of the day, most companies and individuals want to improve and benchmarking is one tool that can enable that to happen.

Benchmarking for benchmarking's sake (also referred to as a "beauty contest") is not always a valuable exercise. I t is h uman

benchmarking nature to look at a list and see who came top. It is also human natu re to want to be at the top of chat li st. However, if this is the only reason you are undertaking the benchmarking, then you are unlikely to generate the valuable ideas and opportunities fo r improvement that benchmarking can deliver.

On the ocher hand , superior performa nce in a benchmarking study can have beneficial outco mes for your business. It can be valuable if you are seeking to motivate your staff, and/or reward superior performance. It can also be valuable as a marketing tool to advertise yo ur performance in the marketplace.

However, it will not help you know how to improve the fundamentals of your business

External Benchmarking Although the process may be similar, external benchmarking has a slightly different purpose to internal benchmarking.

Benchmarking has long been used as an important tool of government owners and regulators to determine the efficiency of a business. Com parative reporting is probably the simplest form of benchmarki ng.

Many govern ments and regulators rely simply on the reporting of costs and service levels to provide a sort of comparative analysis. Public reporting allow the businesses and the public to make their own compa rative assessments of performance - albeit at a high level and to widely divergent criteria.

In recent times, benchmarki ng has taken on a more significant role in the setting of both regulated prices and service levels. In certain cases, benchmarki ng has taken the pre-eminent role in setting the standards.

Utility benchmarki ng has primarily come in two flavours: • Econometric - Examples including Total Factor Prod uctivity (TFP) and Data Envelopment Analysis (DEA).

• Quantitative - Exam ples including process/fun ctional benchm arking.

My experience is predominantly with the more quantitative methods. However, there are relative merits for both.

W hatever, the method utilised, I am confident in saying that the most important criteria for the benchmark (in the eyes of the regulator) is that the results must be defensible.

Why The Two Don't Mix It seems strange to suggest that the rwo approaches fo r benchmarking rhe same businesses should not be done in parallel, but there are good reasons.

Defensibility vs. Opportunity The benefits of an internally dri ven benchma rk will be best realised if that benchmarking program identifies every poss ible opportu nity fo r improvement, whilst the externally driven benchmark seeks to fi nd fu lly defensible and realistic opportunities.

T he potential value of opportunities identified may be enormous, while rhe real-life implementable so lutions wi ll almost inevitably be significa ntly less.

Information vs. Data Internal benchmarks are typically cond ucted in an enclosed environment where only small parts of the business are exposed to the fu ll gamut of opportu nities that are developed. Ma ny of rhese ideas will be controversial and non-viable, but all should be explored befo re they are accepted or rejected.

Idea Generation vs. Selection It is this process of idea generation and exploratio n that is most dangerous. T he majority of ideas and opportuniti es are not viable. Many will fail because they are too expensive to implement. Som e will fail because they are simply coo difficult to implement. Ochers will fail because the company or the environment simply does not allow the opportuni ty co be developed.

Benchmarking - Is It The Start or The End? Benchmarking is a very valuable part of the regulators' and owners' toolkit. I once heard a utility General Manager lament; "If only they had used their powers for good instead of evil". This comment may have been said in jest, but there is a strong element of truth in the statement.

Starting from rhe ground up: • Regulators/owners want an efficient and effective outcome for co nsumers.

• Regulators/owners do not want to run the day-to-day fu nctions of the business and therefore are reluctant to enter into a benchmark study at the functional and operational levels.

• Benchmarking can provide targets for regulators to ser future expenditure levels • A benchmark that does not provide rhe "how" will nor be well received by rhe regulated businesses. The businesses will not be able to confirm their ability to

achieve the proposed efficiency improvements.

• Many benchmarking studies have also failed due to the so-called "Black Box".

This is where the internal mechanisms of the benchmark are unable to be co nfirm ed or reviewed by all parties involved.

However, a benchmarking study char is supported by a technical review can meet the objecti ves of identi fying and validating the opportu nities.

T his will satisfy the regulator/owner in providing a defensible outcome while providing the regu lated utility with a clearer indication of how the efficiencies can be achieved.

Summary In summary, there are excellent reasons to benchmark and significa nt value in benchmarki ng. However, it is important co understand the reasons for undertaking rhe benchmarking study to ensure the outco mes match the needs.

Benchmarking to improve your own levels of efficiency and perfo rmance sho uld be kept well separated from benchmarking for regulators, shareholders and owners as the two outcomes are often inco mpa tible.

Fi nally, as good as benchmarking is, ir will never be able to fully model the intricacies and myriad of environmental facrors ch at impact rhe coses and performance of a water business. From th is perspective, benchmarki ng is a won derfu l tool for quickly providing an indicator of the overall performa nce of a water business. However, benchmarking is not sufficiently accurate a tool to be used to directly establi sh cost or performance targets.

The Author After an apprenticeship with the State Electricity Co mmission of Victoria, Anthony Seipolt undertook a role in uti lity benchmarking for Australian, Asian and New Zealand utilities. Following from chis experience, Anthony accepted a role in N ew Jersey to manage a series of worldwide benchmarking programs. In this rime, Anthony was responsible for over 250 benchmarking studies of water, gas and electrical utilities. Anthony is currently the Australian Manager of Parso ns Brinckerhoff Associates and Director of Parsons Brinckerhoff International (Australia), Level 7, 457 Sr Kilda Rd, G PO Box 47 14 TT, Melbourne, Victoria, email: seipolta@pbwo rld. com

water

SEPTEMBER 2004 43

historical

1

WATER FLUORIDATION: THE ENGINEERS' CONTRIBUTION H F Akers, SAT Porter Abstract The benefits of fluoridation were formally endorsed in North America in 1951 and for nearly sixty years a diverse range of communities have been adjusti ng che fluoride content in water supplies to reduce dental decay. Australian fluoridation commenced in 1953 in Tasmania and expanded to the other states because of the enthusiastic efforrs of engineers in partnership with the dental profession. The purpose o f chis paper is to highlight the early contribution of engineers in fluo ridation research and to acknowledge the role of four Australian engineers, Mr F Grey (Tasmania), Mr HJ N Hodgson (South Australia), Mr MA Simmonds (Queensland) and Dr M J Flynn (New South Wales). The history of fl uoridation and the multidisciplinary approach to its implementat ion has relevance roday as reuse of water and beneficial use of biosolids is subjected to community debate.

The Background to Water Fluoridation I n the early twentieth cencury tooth decay was in epidemic proportions causing not only tooth loss but, in this period before antibiotics and modern anaesthesia, generalised infections and death. The importance of a means of prevention could not be underestimated and one possibility emerged in North America. le

this research in 1931 when they developed a water-borne fluoride assay technique (Ch urchill 193 1).

In 1942, after further multidisciplinary research and epidemiological studies, dental researchers formulated a hypothesis chat in temperate climates 1-ppm fluoride ion in a reciculaced water supply would significantly reduce dental caries with minimal dental fl uorosis. In 1945 Grand Rapids became the first municipality co increase the water fluoridat ion level to 1ppm and commenced a ten-year experiment to rest the hypothesis. Ocher fi eld trials soon followed.

This was in an era of escalating birch rates, increased industrialisation and urban isation with consequent pressure on obtaining, processing and delivering a suitable water supply. While potability and the management of water-borne enteric infections by chlorine were major issues within m unicipal supply, the engineers' perspective of water was wideranging and involved ocher considerations based on quality, quantity and location. In contrast, the den tal profession viewed water as the ideal vehicle for the d istribution of fluoride, which offered a cheap, safe, practical, effective and equitable means of curbing the den tal caries epidemic.

All this early work is summarised in Dr F J McClure's historical monograph (McClure 1962).

The Australian literature on early fluoridation documents significant input from four engi,neers Mr F Grey (Tasmania), Mr HJ N Hodgson (South Australia), Mr MA Simmonds (Queensland) and Dr M J Flynn (New South Wales). was observed chat people with 'mottled' teeth had fewer decayed teeth. T his hypothesis was investigated and upheld by epidemiological scudies that also confirmed a previously held suspicion that red uced dental d ecay was linked to the water supply. HV Churchill (chemical engineer) and AW Petrey (speccrographic analyst) made a pivotal contribution to

44 SEPTEMBER 2004 water

Engineers and Fluoridation in North America Engineers played a key role in early research in to the efficacy of water flu oridation. Churchill's contribution was central to fluoride investigations and others followed. North American municipalities often had detailed records about chemical compositions of aquifers

since groundwater was often used as a so urce fo r potable water. After 1931, researchers appreciated chat changes in aquifer deprh and/or surface supply often meant significant variation in natural ionic fluoride concentrations (McClu re 1962) . Engineers recorded these changes and their collective investigations co ntributed to a series of hypotheses linking ionic fluo ride concentrations in water, enamel fluorosis and caries resistance. One early study chat involved "mottled enamel " in Sou th Dakota was co-authored by a sanitary en gineer, RF Poston, and a dentist, HT Dean. Their fin dings relied heavily on data from the state sanitary engineer, WT Towne.

Records on human and animal fluorosis gathered by dentists and veterinarians could indicate high fluoride levels enabling engineers to investigate the actual levels, and implement defluoridarion technologies o r seek an alternate water source. Once the optimum level of fluorid e became understood, defluoridatio n became the source of attention in chose districts where the natural potable water supply had excess fluoride (Maier 1953). One method engineers used was to dilute naturally over-fluoridated water with lower flu oridated water to produce optimal fluoride levels (Mu rden 1953).

Scientific collaboration between dentists and engineers became more important when addition of fluoride was im plemented . Engineers supplied ionic fluoride within tight concentration parameters. As che aetiology of dental caries is mulcifactorial, dental epidemiology is vulnerable to many confounding factors. Inaccurate or fluctuating levels of fluo ride would not only ruin an investigation but also threaten the development of water fluoridation as a public health measure.

Both engineers and d entists understood epidemiology and had experience in public health. In add ition, the American Water Works Association (AWWA) had kept its members up to dace with the concept of fluoridation from as early as 1943.

Political collaboration was also important.

Engineers had prior experience with chemicals such as aluminium sulfate and

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historical chlorine and were familiar with the controversy that frequently acco mpanied their use. Engineers were also bu reaucratic or industrial ' insiders', who could quietly give aurhorirarive opinions within the political process.

From the engineer's perspective, fluoridati on had characteristics char diffe red from chlorination . Firstly, fl uoridation involved a long period before benefit appeared. Seco ndly, unlike ch lorination, wh ich virtually elimi nated water-borne enteric infectio ns, flu oridation was only a partial solution to a public health problem, albei t an important one. In addition , fluoridation involved an ad ditive process wi th a narrow concentration range. Fluoride was odourless, tasteless and , if imbibed in excess, caused a permanent mottling effect on the developi ng enamel. Unl ike the warning smell of surplus chlorine, excess fl uoride could nor be detected without analysis. Rapid an d accurate water-based fluoride monitoring was essential for therapeutic dosage and effective fail-safe systems. Agai n engineers played pivotal roles in the

evolutio n and implementation of such assay, screening and safety technologies (H arper 1951).

By 1951 , approximately 13,000 public water supply systems serviced 85,000,000 people in the Uni ted Scares delivering approximately 15 bi llion gallons of water per day (57Gl/d) (Allen et al. 1951).

When water fluor idation was approved for a municipality, engineers custom ised the installations based on economics, space, feed ing mechanism and safety protoco l (Harper l 951 ). Sanitary engi neer FJ Maier and chemical engineer E Bellack were responsible for early research into the engineering problems and waterworks safety protocol involved in the dispensing of fluo ride into the water supply (McClure 1962). T he news magazine of the American Chemical Society, Chemical and Engineering News, also carried regular articles on fluo ride related matters, including transport guidelines (M iller 1949).

The Crystallisation of an Opposition Between 1945 and 1952, 183 United States' com munities adopted water

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fluoridation but only twenty-four involved referenda and by 1953, fourteen communities had discontinued fluoridation (Crain et al. 1969, Black l 955). Between 1951 and 1954, overt opposition to water fluoridation had emerged in the United States. While the first defeat of fluoridation at a referendum occurred at Stevens Point in 1950, rhe resounding defeat (86,230 to 44,814) of fluoridation in Seattle in 1952 attracted extensive publicity (1952, Crain et al.

1969). Two congressional hearings, one on chemical additives to foods and cosmetics in 1952 and the other on a bill ro prohibi t fl uoridation in 1954 provided widely publicised arguments for and against wa ter fluoridation resulting in rhe formation of an incernarional anti-fluoride movement (Dory eta!. 1952; Danziger 1954).

Between 1946 and 1950, water fluo ridation was novel and almost universally welcomed, bur by 1952 the "honeymoon" acceptance period was over and convincing communities to adopt water fluoridation usually became a political rather than health issue.

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historical North American Water Fluoridation and the AWWA The liaison between AWWA and den cal researchers on fluoride was longstanding.

Two dental researchers (HT Dean and D Ast) delivered papers on dental epidemiology, fluoridation and dental caries to the 1943 AWWA Conference. An AWWA policy accepting controlled experimental tests into water flu oridation soon followed (Wolman 1943) . Between 1943 and 1949, the water works ind ustry generally approved concrolled pilot studies bur recommended avoiding a more general adoption of water fl uoridation until rhe completion of those studies (Faber 1949).

In 1949 there was a significant AWWA policy change to accept wider water fluoridation under certain conditions. The policy now read (Black et al. l 949): "In co mm unities where a strong public demand has developed and the procedure has che full approval of che local medical and den cal societies, and the local and state health authorities, and ochers responsible for che communal health, water departments or companies may properly parricipace in a program of fluorid ation of public water supplies."

This modification was adopted during the "honeymoon" era fo r fl uoridation acceptance and largely preceded the emerging socio-political controversy surrounding water fluoridation. It established protocols and accelerated fluoridation. Engineers were given a clearly defined positio n and uniform installation procedures. Fluoridation now involved a fee that was levied on health departments rather than as per capita water co nsumption cost, recognising fluo ridation as a health responsibility. Furthermore, public ucilicies accepted liability for negligence for too high and roo low a dosage (Black et al. 1949). As the sole municipal provider, water utilities

occupied a privileged legal position. They had dual accountabilities (Waldrep 1952).

T he first was a proprietary respo nsibility to supply water profitably. The second was a governmental role to benefit the public.

By 1952, the AWWA investigated the legal issues invo lved in water fluoridation and advised its membership chat although the fluoridation process was legal, there were obscurities involving public indemnity (Murdoch 1952, Waldrep 1952).

T he 1949 policy also meant chat AWWA accepted the validity of the dental evidence, whilst the longitudinal experiments were still under way.

Moreover, che active participation by the engineering profession implied that ic was comfortable with artificial fl uo ride protocols and with the safety aspects of the narrow concentration limits. O ther feeder compounds that offered economic advantages could now be investigated more thoroughly. While co mparatively few engineers became overt fl uoride advocates, the Journal ofthe American Water Works Association kept its membership well informed. Between 1948 and 1953 it published at lease twenty-five fl uoride related articles. These incl uded articles by high profile researchers, the National Research Council, attorneys and even "Questions and Answers" co public questions. T here was also discussion on alleged problems involving ice manufacture, fermentation procedures and wee-milled co rn. In addition, there was obvious collaboration between dentists and engineers in official AWWA statements (Black et al. 1949).

Background to Australian Water Fluoridation Australian dentists were able co follow North American developments on fl uoridation in their local dental publications. Nonetheless, Australi an

scientific bodies appreciated chat water fluoride implementation could not be merely translocaced across the Pacific if for no ocher reason than the higher water ingestion in tropical climates such as North Queensland. The Australian background co water fluoridation was vascly different from North America's. In Australia the only co mmunities with naturally occurring fluoride in drinking water with levels approaching or exceeding !ppm were in rural and remote areas. The populations involved were coo small co attract che attention of epidemiologists.

Moreover, che Commonwealth Department of Health did not have the authority, finances or cohesive national approach of che United Scares Department of Health, Ed ucation and Welfare. The United Scares Publ ic Health Service, which was responsible for much of che multidiscipli nary organisatio n within the North American field studies, had no Australian equivalent. Furthermore, Australian dentistry did not have the same resea rch culture as N orth America.

Epidemiological invescigacions into the incidence of den tal caries and fluor ide ingestio n were lacking in Australia of the l 940's. The National Health and Medical Research Council (NHMRC) was Australian's peak advisory body on scientific developments. In che immediate post-war era, the dental activities of che NHMRC were limited and , in the case of fl uoridation, restricted by its charter. The NHMRC funded research but did not offer legislative or fiscal recommendations.

Resources were limited and den cal research had co compete for grants with research into diseases such as poliomyelitis and tuberculosis. Dental research was the functio n mainly of universities where there were also fiscal restrain cs. Furthermore, after 1953 the Dean of the University of Melbourne Dental School, Professor (lacer Sir) A Am ies, emerged as a high profile

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46 SEPTEMBER 2004

water

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historical anri-fl uoridacionisc. As a co nsequence, Mr N Marrin {lacer Professo r and Dean of che University of Sydney Deneal School), and Sydney's embryo nic Institute of Dental Research, provided rhe early research into dental ca ries and flu oride.

Formal Australian acceptan ce of flu oridation did not occur until December I 953, when rhe NHMRC prepa red its scientific protocol. This delay placed Australian water fl uoridation firml y into the political arena of the emerging anti flu oridation movement withou t th e "honeymoon" period enjoyed by North America. During ch is period, che dental profession was fragm ented across state bou ndaries. Al though the federal rep resentative body, rhe Australian Deneal Association (A DA) existed, ic did not have the established structure and profile of the America n Deneal Association. Th is impeded the advocacy role of rhe ADA. Furthermore, although politicians tacitly acknowledged caries as a national problem, fluo ridation could nor be implemented on a national basis because health was not a mainstream federal respo nsibil ity and even at the state level, co mpli cations arose from che different legislative control over water

supplies. T he co llective co nsequence was a widespread lack of co-ordination within flu oride advocacy, which furth er delayed flu oride implementation (Edi torial 195 1).

Engineers and Fluoridation in Australia T he Australian lirerarure on ea rly flu oridation documents significant input from fo ur engi neers - Mr F Grey (T asmania), Mr H J N Hodgson (South Australia), M r M A Simmon ds (Queensland) and Dr M J Flynn (New Souch Wales). Grey was the Beaconsfield Municipal Council's Waterworks Superviso r, whose enthusiasm and support was responsible for the 1953 Australian fluoridation debut at Beaconsfield. G rey, a graduate from the Melbourne Technical Insti tute, was an industri al chemise, merallurgisr and mini ng engi neer. He solved persistent turbid ity problems with in rhe municipal warer supply, which endeared him locally because people now enj oyed "a real cup of tea" (Hooper 2000).

Grey tu rned his attention co water fl uoridation, which had mini sterial , departmental and local auth ority support because of a perennial shortage of dentists

in T asmania. Grey knew about rhe benefits of fl uoride in the United States (Australian Deneal Association-Federal Branch 2003) .

Beaconsfield was the fi rst town to adopt water fl uoridation in Australia and it was an independent municipal authority decision. T asmania generally loo ked to Victoria for its dental science info rm ati on but on water fluoridation Amies' views were an emerging problem. T his evidence and local archives suggest chat G rey's practical info rmation came from AWWA, whi ch by 195 l had published detailed instructions about fl uoridarion equipment (Harper 195 l ). G rey's flu oride interest was enhanced by his co ncerns abou t his daugh ter's teeth and he received mi nimal, if any, dental input. Unlike the North American pilot studies, Beaconsfield was not es tablished as a con rrolled experiment bur became important in investigations of che dental effects of fl uoridation.

The first authoritative govern ment report on Australian water fluo ridation was pu blished in South Australia (Hodgson 1954). Ics author was a water and sewerage treatment engineer, who was attracted to the concept of water fluoridation after a visit to No rth America, the United

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historical Kingdom and Europe. Both N orth American engineers and the 1949 AWWA policy on responding co public d emand for fluoridation influenced Hodgson. H e recommended chat "serious thought" be given co a pilot for South Australian fluoridation. After a ten-year dormancy period, H odgson enthusiastically presented his report b efore the South Australian Select Committee on Fluoridation (I 964), which laid the foundations for a decision "by decree" fo r the water fluoridation of Adelaide in 1968 (The Select C ommittee of the House of Assembly 1964). Hodgso n convinced the C ommittee chat "there are no engineering or mechanical problems in che fluoridation of water supplies" and his testimony was important in refuting antiflu oride statements by Professo r Sir Stanton Hicks from the Department of Physiology and Pharmacology at the University of Adelaide.

Simmonds graduated in 1929 from T he University of Queensland as a chemical engin eer. H e lacer became Engineer-inC harge at che Brisbane C ity Council's Mc Crosby Water Plant. In 1949, he joined che Queensland Department of Local Government, as Executive Engineer

(Chemical). In 1952, Simmonds advocated the fluoridati on of Townsville's water supply, but his proposal was premature in chat there were no NHMRC guidelines in place. Queensland h ealth bureaucrats and the Australian D eneal Association (Queensland Branch) rebu ffed Simmonds' proposal (Simmonds I 952) . Regrettably, many of his early archives were destroyed in the 1974 Brisbane flood. However, in a manuscript published in the 1952 Queensland Dental Journal he displayed a detailed k nowledge of fl uoridation including contemporaneous material on dosage variation related co age and climate.

T h is paper exposed an enthusiasm, persistence and ability co network within government departments. Simmonds was clearly d isappointed by Queensland hesitance co adopt his recommendations. It is arguable chat Sim monds was the fi rst water flu oridacon advocate in Queensland (Akers et al. 2004).

Simmonds' professional fi les confirmed his commi tment co water fluoridatio n.

W hile he relied on informatio n from the AWWA, he also had contact with the American and Australian Deneal Associations, the NHMRC and

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Queensland's leading health offi cials. In 1955, Simmonds wrote an unpublished paper, Fluoridation ofPublic Water

Supplies: A Water Engineer's Point of View, which, at rhac rime, was rhe most derailed report on fluoridation in Queensland (Simmonds 1955). It concluded, "As engineers we m erely await an instruction from those in au thority." Simmonds was related co Mr G Simmonds, a dentist and emerging fluoride advo cate. Style and references suggest rhar they collabo rated with publications (S immo nds 1951, Simmonds 1952). M Simmonds was responsible for some of the p lanning and infrastructure of a Queensland flu oridation plant at Dalby. H is intimate knowledge of fluoride levels within rhe state's artesian system precipitated an interest in d efluo ridarion technologies, especially in the northwest.

The las t 'engineer' in th is discussion of early flu oride engineers is Dr M J Flynn , who was appointed Chief Medical Officer of the Metropolitan Water, Sewerage and Drainage Board (Sydney) in 1957. Flynn, whose curriculum vitae included medical, engineering and public health qualifications, became a major influen ce within Australian fluoride policies. He au chored a 1964 report on flu oridation for the N ew South Wales government and copublished with Marcin, whom he regarded as one of two men who were leaders in Australian fluoridation (Flynn et al. 1963, Flynn et al. 1964) . Flynn named his colleague Hodgson as the second leader, and at the 1964 South Australian Select Committee hearing, endorsed Hodgson 's 1954 view that South Australia should initiate fluoridation (T he Select Committee of rhe H ouse of Assembly 1964). W hile chis Flynn-H odgson synergism was influential in South Australia, it was exceeded on the Australian stage by the Flynn-Marcin liaison. This associatio n amalgamated the multidisciplinary interests within fluoride advocacy, namely d ental, medical, communal h ealth and engineering expertise. Boch Flynn and Marcin became W orld Health Organisation consultants; New South Wales Fluoridation Advisory Committee Mem bers and Flynn lacer became President of the Australian Water and Wastewater Association. Although Flynn traversed Australia as an expert witness endorsi ng fluoridation he met his biggest test in Sydney. In mid-1963, the M ecropolican Water, Sewerage and Drainage Board rejected his advice and voted 4-2 again st fluoridation. The New South Wales' Minister for H ealth, WF Sh eahan, qu ickly attacked the Board's

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decision. Sheahan endorsed Flyn n and his stand on fluori dation, which precipitated state government action chat was responsible for much of che fl uoridatio n of water supplies with in New Sou ch Wales.

Flynn's unequivocal co mmitment was demonstrated in the Victorian Supreme Court where a 1964 legal challenge co municipal fluoridation was underway. In an at tempt co demonstrate the safety of fluoridated water at 1ppm, Flynn dissolved cwency mi lligrams of sodium fl uoride in a glass of water (which became 50ppm fl uoride) and drank it before Justice Gilliard (1964)). The testament co Flynn's profile and effectiveness is reflected not only in his achievements, bu r also in ch e accen tion he received from anci fl uoridacioniscs.

Acknowledgments T he authors thank Mr J Bristow, Mr R Coleridge, Mrs E Cullen, Professor GN Davies, Mr J Mobbs, Mr B Nechercoce and Dr R Wear.

The Authors Dr Harry Akers is a general dental practitioner, Bundaberg, and PhD student ac The University of Queensland. Dr S A T Porter is a Iecru rer ac che School of Dentistry, The University of Queensland.

HF Akers, 59 Barolin Sc, Bundaberg, 4670. Phone (07) 4152 6214, Email harry.akers@b 130.aone.ner.au

References 1952 'Editorials - Verdict in Seat tle: Referendum on Fluoridat ion.', j Am Dent Assocn 44(4):457-59 .

1964 ' Court Drink Backs Case on Fluoride', The Age. 5 March 1964: 16.

Akers H & Porter S, 2004 'A H isrorical Perspective on Early Progress of Water Fluoridation in Queensland 1945-54: Sh eep, C limate and Sugar', Aust Dent j 49(2):6 1-66.

Alle n J, Cunningham MB, Frye JC, Lawrence RE, Mohlmann FW, Powell ST, Rawn AM & Weston A, 195 1 'National Water Policy Engineers Joint Counci l Committee Report', }our. AWWA 43(1):24-30.

Austral ian Dental Association (Federal Branch) 2003 Fluoride: Nnture Thought ofit First, Australian Deneal Associatio n (Federal Branch), Sr Leonards.

Black A, 1955 ' Facts in Refutation of C laims

by Opponents of Fluoridation' , j Am Dent Assocn 50Qune):655-64 .

Black A, Berry AE, Faber HA, Faust RJ, Weir WY, Dean HT & Enslow L, 1949 'The Fluoridation of Public Water Supplies Sraremenr of Recommended Policy and Procedure', ]our. A WWA 4 1( 1):575-79.

Church ill H , 1931 'The Occurrence of Fluorides on Some Waters of the United Scaces',jour. AWWA 23(9): 1399-1407 .

Crain RL, Karz E & Rosenthal D, 1969 The

Fluoridation Decision, Bobbs-Merrill, New York.

Danziger C, 1954 'Science vs Fanaticism: A Report of the Hearing on t he Weir Bill co Prohibit Fluoridation' , j Am Dent Assocn 49Quly):86-89.

Dory, JR & Phair W, 1952 'An Analysis of rhe Delaney Commi ttee Report o n the Fluoridation of Drinking Wate r', j Am Dent Assocn 45(Seprembcr):351-6.

Editorial 195 1 'Fluoridation of Public Water Supplies' , DJ Austrnlin 23( 1-2):42-43.

Faber H, 1949 'The Scarus of Fluoridation in 1949',Jour. AWWA 4 1(1 2):1 061 -68.

Flynn M , Brothers P & Johnson D, 1964 lectures Given flt Fluoridntion Seminnrs, Department of H ealch - Q ueensland, Brisbane.

Flynn M & Marrin N , l 963 'Fluoridation: Basic De neal, Medical and General Aspects', Med] Awt 1(5): 154-59.

H arper L, 195 1 ' Fluoride Chemical Feeding', ]our. A WWA 43(9):744-62.

Hodgson H, 1954 The Fluoridntion of Public

Wnter Supplies ns n Menns of Controlling Dentnl Caries - Report ofnn Enquiry, T he Engi neering and Water Supply Depamnenr, Adelaide.

Hooper R, 2000 Personal communicat io n co H Akers, 14 April 2000.

Maier F, 1953 ' Defluoridarion of Municipal Water Supplies' , ]our. A WWA 45(9):87988.

McClure F, ed 1962, Fluoride Drinking Wnters, US Department of H ealth, Edurnrion and Welfare, National lnsrirure of Deneal Research, Bethesda.

Miller H , 1949 'Safe H andling of Fluorine Chemicals', Chemicnl nnd Engineering News 27(52) :3854-57.

Murden X, 1953 'Narural-Fluoride Well Water Added to Portsmouth Surface Supply', ]our.

A W'WA 45(4):363 .

Murdoch J, 1952 'Legal Problems Confronting Water Works Management', }our. A i\:1/WA 44 ( 12): 1085-91.

Simmonds G, 1951 The Use of Fluorine in the Control of Caries', Queenslnnd D j 3( 10):322-26.

Simmonds M, 1952 'Medication of Water Supplies', Queensland D j 4(1 1) :388-93.

Simmonds M, 1955 Flttoridntion ofPublic

Wnter Supplies - n Wnter Engineer's Point of View, unpublished personal paper, Brisbane.

The Select Committee of the House of Assembly, 1964 Report of the Select

Committee of the House ofAssembly on the Fluoridntion of Water Supplies, The South Australian House of Assembly, Adelaide.

W aldrep B, 1952 'Mun icipal Liability in Damage Suits from Fluoridation', ]our.

AWWA 44(1 ): 10- 14.

Wolman A, 1943 'What Are the Responsibilities of Public Water Supply Officials in the Correction of Deneal Deficiencies', ]our. A i\:1/WA 35(9): I 1981200.

Design and construction of sewage and industrial wastewater treatment projects using the Hybrid BNR process In July 2004 Triwater Australia Pty Ltd was formed - by a partial management buyout from Simon Engineering (Australia) Pty Ltd and a merger with Aeroflo Pty Ltd of SA. The Triwater team has a track record of building 550 wastewater treat ment and reuse projects over the past 22 years producing a high quality treated effluent (including N&P removal) for: • sewer mining applications - e.g. golf courses • communities up to 10,000 persons • mine sites • tourist resorts • mobile home vi llages • industries producing high strength BOD 1 wastes Triwater is a small team of specialist professionals focusing solely on wastewater treatment with 3 decades of experience, albeit trading under different names, such as AAT and Tubemakers Water, but with a particular emphasis on 3 virtues: • Value • Innovation and • Service

Contact:

•• '

Ray Anderson on 02 8707 7700 Graham Furber or David Potter on 08 8370 3130 ray.anderson@triwater.com.au or www.triwater.com TR I w ATER

Politics of Community Conflict: The

refereed paper

water

SEPTEMBER 2004

49

STABILISATION OF BIOSOLIDS USING THE AGITATED AIR DRYING PROCESS R E Desmier, C Liston, L M Sickerdick Abstract Agitated Air Drying (MD) is a process that accelerates the drying and stabilisation of mechanically dewatered sewage sludge by using machinery to frequently turn batches of windrowed material which are fo rm ed by back blending finished product with dewatered sludge.

This paper describes the implementatio n of the MD process at Bolivar WWTP and the results of the intensive monitoring trials. The results of other wo rk chat examines the extent of stabilisation that can be achieved with lagoon dried and stockp iled biosolids will also be presented.

The findings from these trials have resulted in refinements being made to the So uth Australian Biosolids Guidelines with the likely introduction of a new and higher stabilisation standard being sec for biosol ids used on agricultu ral land.

Introduction The South Australian Water Co rporation (SA Water), since 1996, has contracted Un iced Water to manage and operate its water and wastewater services, incl uding a program to maximise beneficial reuse of the biosolids produced by che wascewacer treatment planes (WWTPs). Together, SA Water and United Water have implemented one of the most successful biosolids beneficial use programs in Australia. For the past five years the quantity of bioso lids reused has exceeded production and annually, the equivalent of more than 30,000 dry tonnes of biosolids were collected by farmers fro m the Bolivar plant and used mainly on arable cropping land to the north of Adelaide. All biosol ids produced from the Adelaide wastewater plants are beneficially used and there is no discharge of sludge to the mari ne environment.

The recent upgrading of rhe Bolivar WWT P to activated sl udge (replacing rhe T his is an edited version of a paper presented at the AWA Biosolids Speciality Conference, June 2004. T he CD ROM for all the papers is available from the AWA office, Artarmon.

50 SEPTEMBER 2004

water

trickling filters) has required rhe introduction of new sludge handling methods. In order chat che resul ting biosolids produced can be incorpo rated easily into the existing beneficial reuse program it has been necessary to demonstrate that they have undergone adequate stabi lisation for grad ing, appropriate to che intended use, in accordance with the South Australian Biosolids Guidelines. The biosol ids are

decommissioned. The improved creacmenc of che wastewater resu lted in an increase in che production of sludge. In addition, che commissioning of a tertiary treatment plane in 1999 capable of supplying up to 120 ML/d of Class A reclaimed water for unrestricted irrigation of horticultural crops, further increased sludge production ac the plane. To avo id additional volatile sol ids loading on che sludge drying pans chat already occasio nally experienced odour

Stabilisation in mechanically turned windrows is monitored to achieve the South Australian Biosolids Guidelines. The biosolids are stockpiled and mainly shipped off-site in late summer. stockpiled for most of the year and are mainly shipped off-site in late sum mer and autumn.

problems, alternative sludge management processes needed to be incroduced.

Background

SA Biosolids Guideline Requirements for Agricultural Use

The Bolivar WWTP, with a current flow of 160 ML/d is the largest wastewater treatment plane in South Australia. In 2002 the planc was upgraded to an activated sludge process and its trickling filters were

The SA Biosolids Guidel ines were developed in 1996 and are currently being reviewed. The current guidelines contain cwo stabilisation grades as follows:

refereed paper

Table 1. Climate Averages Edinburg h RAA F Ba se (6 km from Bo livar WWTP].

Jan

Feb

Mar

Apr

May

Jun

Jul

M ea n doily evop - mm

10.2

30 16.5 15.4 3.5 9.7

26.6 14.3 25.3 5.6 7.3

22.7 l l.5 30.3 7.9 4.8

19. l 9.1 43.8 12 2.8

15.9 6.8 53. l 13.9 l.8

15.3 5 .9

Mea n no. of roindoys

29.7 16.3 22.7 4.2

Element

C min temp - deg C

Mea n max temp - deg Mean

Mea n rainfall - mm

• Grade A - Contains <l Salmonella/50g ds, <l helminch/50g ds, <l virus/50g ds, <l Cryptosporidium or Giardia/50g ds; • Grade B - Lagoo n dried and stockpiled (for not less than 1 year} and has a fi nal dry so lids content of> 75% (if digested) or >90% (if undigested).

Boch grade A and B can be used for agricu lture, comprising broad acre crops, vines, olives and cirrus. Use of biosolids on ann ual crops such as vegetables is not permitted in Sou th Australia. In co mpariso n, the draft National Biosolids Guidelines, May 2002, allow biosolids with rhermo coleranr coliforms < 2,000,000/g <ls ro be used in rhe above mentioned agricu ltu ral applications.

Th e current review being undertaken of rhe SA Biosolids Guidel ines includes a

55.7 14.7 2

Aug

Sep

Oct

Nov

Dec

Annual

16.4

18.7 8.1 49.3

22.5

12.7 3.9

12.6 25.3 6.9

27.7 14.7

15.4 2.7

21.8 10 43.5 10.7

25. 2

6.5 50.9

2 3.2 6. 1

11 438.5 1 13.4

5.7

8

9.5

5.7

review of rhe criteria for srabilisarion grade A and B material. T his review proposes ro: • modify the Grade A criteria co incl ude an E.coli requi rement of <100 cells/g <ls and co remove the current Cryptosporidium and Giardia criteria; • incl ude pathogen criteria fo r rhe Grade B standard.

Sludge Management Ir was decided that solar drying of rhe sludge in lagoons would co nti nue as this is by fa r rhe most cost effective method and it used passive so lar energy with minimal add itional energy input and commensurately lower im pact on greenh ouse gases. However, co minimise odour production from chis part of rhe process, rhe volatile solids load ing would

need co be reduced and sludge in excess of the capacity of rhe lagoons would be mechanically dewarered. Two centrifuges with a combined throughput of up to 48 dry tonnes/day (at an output sludge cake of 24% coral solids) were installed. Whilst some Australian guidelines permit use of biosolids char have been anaerobically digested and mechan ically dewacered di rectly co agricultu ral land, the South Australian Guidelines require rhe sludge ro be aged for ar leas t one year and further dried co 75% solids, before ir can be used for chis purpose. Given chis guideline req uirement and the potential fo r odours arising from rhe storage of dewarered sludge cake, rhe need fo r additional treatment was therefore co nsidered.

A co mmon option adopted fo r further stabilisation of cen tri fuged cake involves

~~

Ten Cate Nicolon

geotubes • effective high volume containment • efficient dewatering & volume reduction • on-site dewatering • no special epuipment required

Most municipal sewage treatment plants become inefficient because their digesters and lagoons become filled with sewage sludge past safe operating levels.

Traditional methods of removing the sludge require the use of heavy equipment for dewatering before it can be THE SOLUTI ON is large Geotubes into which the sludge can be pumped d irectly from the digesters and lagoons. The permeable rem oved from site for disposal in a landfil l. geotextile outer layer allows sludge to be efficiently dewatered For application details contact ... w hile containing the fine-grain solids of the sludge.

CRS Industrial Water Treatment Systems P/L P-02 9899 7811 F-02 9899 7336 crs@watertreatment.net.au

refereed paper

r'.l'&~~:~~Ls~'r'.:\!'s

33/9 Hoyle Ave, Castle Hill NSW 2154 Australia www.watertreatment. net.au

water

SEPTEMBER 2004 51

the use of lime to raise rhe pH and rhe temperature of the material. This was nor a preferred optio n in chis situation for several reasons. Firstly the bulk of the material char must be handled is increased, giving rise to diluted nutrient benefit of rhe biosolids and increased reuse costs. I n addition most biosolids reuse in South Australia is on alkaline soils where additional lime would no r improve co ndi tions fo r plant growth.

Furthermore while biosolids reuse was already occurring, this was mainly during su mmer and autumn, and therefore the need for short term stockpili ng still remained. There was a concern char rhe stockpiled, lime amended d ewarered biosolids would give rise to odours as the alkalinity decreased with time.

Thermal drying and pelletising the biosolids was also ruled out due to the high capital and operating coses involved.

Composting with other materials such as green waste was not considered practical due to an apparent saturation of urban markers for composted products. I n additio n the fact that the South Australian Biosolids Guidelines do not have a totally unrestricted use classifi cation for biosolids produces and p rohibits use on some horticul tural crops reduces opportunities to use co-composted biosolids produces in agriculture.

Agitated Air Drying (AAD ) was selected as a treatment process worth further investigation as it was a low energy input method that made good use of Adelaide's warm, dry climate (refer Table 1).

Furthermore sufficient land fo r implementation of the scheme was available at the Bolivar WWTP. Wind row turning machinery was hired from a local compose manufacturing company to sim ulate as near as possible the AAD process and following successful trials (Lane et al 2002) tenders were called for rhe supply of machinery for a full scale operation. A 5 ha processing site was prepared for the activity adjacent to the centrifuge plant. A variety of windrow turning machines were tendered and they were evaluated jointly by SA Water and United Water. It was eventually decid ed char SA Water would purchase two Backhus 15.50 units. These units offered the advantage that an attachable side conveyor could be purchased enabling the windrow turner to not only turn the windrows, but also to load the windrow material directly onto a truck or to move rhe windrow laterally on the processing pad.

T he benefits obtained in using this type of machine were: • ability to place windrows closer together o n the processing pad, conserving available space; • more efficient loading of fin ished windrows into trucks;

52 SEPTEMBER 2004

water

BAY1

BAY2

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.

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Figure 1. Layout of wi ndrows.

• more efficien t rotation of windrows on the processing pad;

windrows are always for med from one side of the bay and on comp letion of p rocessing they are removed from the opposite side of the bay. Followi ng removal of a dry, processed windrow all the o ther windrows in a bay are moved across usin g the conveyo r attachment during the next turning operatio n (Figure l ).

• lower costs for ancillary equipment (eg front end loaders).

The Agitated Air Drying Process at Bolivar The process utilises a windrow system of sludge handling with several windrows placed as close as possible together in groups o f windrows (bays). Each bay consists of fi ve o r six windrows. Placing the wind rows close together is an efficient way to utilise the area however removal of windrows char have been processed together with placement of sl udge for new windrow fo rmatio n becomes d ifficult as there is limited opportunity for machinery access once adjoining windrows are in place.

Using the bay system allows access to the windrows at either side of the bays for removal and placement. At Bolivar the new

Formatio n of a new wind row com mences by laying a bed of previously p rocessed material along the length of the location (ie backblending). An approximately equal amou nt by vo lume of centrifuged cake is then placed on top of rhe dry bed and the blend can then be mixed with rhe turner.

Dewarered sludge (20 to 24% TS) is backblended with finished product (65% TS or more) to produce a mix of approximately 40%TS. Ir has been found that rhe rapid transition from wet to approximately 40% TS over a period o f a few days opens up the structure of the

Bolivar WWTP - Agitated Air Drying of Blosollds Total Solids - Summer and Winter Trials 100

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rsc1 • .,;21

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TS (1Z-15)

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Figure 2. Drying rates.

refereed paper

Bolivar WWTP - Agitated Air Drying of Blosolids E.coli - Summer and Winter Trials 10,000,000 ~ - - - - - - - - - - - - - - - - - - :- . .- . ..-,.-,..-.:-,-,...

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E .col (1 9..62)

E.cdl(9)

e .co11(12-1,)

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e.coll(Z0-22)

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Figure 3: E. Coli summary for summer and winter AAD trials. sludge and minimises rhe generation of odou rs.

Each windrow is turned every one or two days, except during rainy periods when surface moisrnre is allowed to dry to avoid re-wetting previously dried material. Ir was found that the moisture from rain does not generally penetrate more than 50 co 100mm. Windrows start off approximately 4 to 5 metres wide and form a tri angular shape when mixed from I to 1.2 m high in the cen tre.

Monitoring Program An intensive monitoring program was initiated in 2003 to evaluate the effecriveness of rhe process both for stabilisation of the biosolids produced and as a means of drying rhe biosolids. T he objective was to document the progressive changes in rhe windrowed biosol ids from placement to when they were dry enough co remove from the processi ng pad co a stockp ile and to demonstrate to SA EPA that the AAD process produced an adequately stabilised produce. Mon itoring was undertaken on three distinct batches of biosoiids during rhe sum mer and again during rhe winter period. In addition another batch that was blended at a ratio of two parts wet cake with one part dried biosolids (instead of the usual I: 1 ratio) was monitored during the summer period. Each batch consisted of three days output from th e centrifuge pl ant (Friday, Saturday and Sunday). The wind rows were formed and blended on the followi ng Monday and samp ling commenced fo llowi ng the first pass of the windrow turner on rhe T uesday.

Five composite samples were collected from each biosolids batch weekly for rhe summer monitoring and forrn ighrly for the

refereed paper

winter mo nitoring period. Samples were analysed for total solids, volatile solids, Salmonella (per 50gm TS) and E.coli (per gm TS). Those samples char were fo und co be compliant with the proposed Stabilisation Grade A criteria for E.coli and Salmonella were further analysed for the presence of virus and helminths (both per 50 gm TS).

Sum mary graphs showi ng the rate of drying and die off of E.coli for all windrows monitored are shown in Figures 2 co 4. Nor su rprisingly, the drying rate of the agitated air dried biosolids was considerably faster in su mmer compared co char in winter (Figure 2). The average rime for the total so lids co reach 75% was 50 co 60 days from placement in summer and 100 to 120 days 111 Winter.

Figure 3 shows char the E.coli die-off was also much faster in summer compared to winter. Both the summer and winter

windrows ach ieved below 2xl06 cells/gm (draft National Guideline lim it for biosolids used in crops consumed that are cooked or processed) withi n about one week of forming the windrow. An E.coli count of 1000 cells/gm or less was achieved after I 5 co 30 days in summer and approximately 40 to 50 days in winter. Furthermore an E.coli count of I 00 cells/gm or less was achieved after 20 co 35 days in sum mer but rook 60 co 70 days in winter.

Figure 4 illustrates a summary of coral solids and E.coli data collected during the winter and summer trials. The data plotted on chis graph is rhe average data for each of the summer and winter windrows. T rend lines (lines of best fir) have been superimposed onto the graph , co faci li tate concl usions from the data. In fact the individual data points (not just rhe average as shown in Figure 4) indi cate char after 49 days there were no samples chat were less than 50% total solids or had an E.coli count greater than I 000/gm.

Salmonella were not enumerated in rhe study and samples were only analysed for presence or absence (per 50 gm TS).

During sum mer the orga nism was fo und to be absent in 100% of samp les after 49 days for two of the three batches monitored and 62 days fo r the remaining batch. In all cases rhe total solids was in the range of70% co 75%. During winter the organism was absent in I 00% of sam ples for on ly two of the batches monitored, after 71 clays (although some regrowth occurred after 97 days) and 91 days respectively. The third batch still contained some Salmonella after 9 1 days. In all cases rhe total sol ids was approximately 60%.

Samples collected that were found to comply with rhe proposed Stabilisation Grade A for Salmonella and E.coli were further analysed for helminrhs and vi ruses.

Bolivar WWTP - Agitated Air Drying of Bloeolids

E.coli and Total Solids - Summer and Winter Trials 100 90

10000000000 Not. · · ~•17& 14dly~•for ....tnffl81'and W11'Mfdll.laruplldively Ead'IM•P0il1 •.th1.,.... ol iwnn,pAu 9Ymrn.-yoidlll1 Fl i'1,l{N3&4

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80

100

120

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No. dayo 1lnc• windrow form.cl • TS(1umrrw,r)

a TS (wlnt•r)

• E.coli (1umrrw,r)

• E.coli (wln!M)

Figure 4. E.Coli and total solids summary for summer and winter AAD trials.

water

SEPTEMBER 2004 53

Table 2 Stockpile Age

Max/ Ave/ Min

Total Solids (%)

E.coli (cells/ g ds)

Salmonella (cells/ 50g ds)

Helminths (ova/ 50 g ds)

Viruses (PFU/ 50 g ds)

1 to 2 yeors

Maximum

68 63.4 57

<l <l <l

<l <l <l

0 0 0

<l <l <l

83 70.3 57.8

2 <l.2 <l

<l <l <l

0 0 0

18 <l

88. l 81.3 78

<l <l <l

<l <l <l

0 0 0

<l <l <l

Average M inimum 2 to 3 years

Maximum Average Minimum

3 to 4 years

Maximum Average Minimum

A total of 30 samples were analysed before the program was concluded. Viruses were found to be present in eight of che thirty samples. No helminths were detected in any of the samples. Total solids of the thirty samples ranged from 57.3% to 78.2% and averaged 65.7%.

Ocher monitoring of the windrows during che trial included volatile solids, temperature, odour and particle size distribution in the processed product.

Analysis of volatile solids data indicated a reduction in excess of 38% from centrifuged cake ro stockpiled material in addition to the reduction that was achieved during anaerobic digestio n. The temperature monitoring indicated that there was not a lot of composting activity occurring in the windrows between turns, probably due to the low volatile solids, small windrows and freq uent turning.

Pathogen decay is therefore attributed to desiccation and ageing as opposed to heat treatment resulting from any composting action. Odour monitoring was qualitative only and was only assessed by sampler observations. There was some odour from freshly form ed windrows bur ir was considered ro be localised and after a week or so it was not possible to identify whether odours were from target or adjacent windrows. Odour emanating from the processing site as a whole was not considered to be a maj or problem, however rhis will be more thoroughly assessed during 2004 when an odour survey fo r the facility is undertaken. An assessment of rhe particle size distribution in rhe processed material was made by comparing ir with lagoon dried biosolids that had been screened in preparation for supply to users. le was concluded chat there was little difference in the composition of biosolids produced by each process although the more vigorous handling of the AAD material during turning created more dust when dry.

In summary, monitoring results from che full scale operation of the AAD process at Bolivar indicate char a significant level of 54 SEPTEMBER2004

water

pathogen destruction can be achieved by chis process. W hile it is still uncertain from the monitoring undertaken what would be required to achieve a Stabilisation Grade A produce, the process can easily achieve a high pathogen quality.

Analysis of Lagoon Dried Biosolids In another srndy representative samples of sludge were collected from maturing stockpiles held at Bolivar to assess pathogen die off races for E.coli, Salmonella, viruses and helminchs. Five samples were collected for every 2,500 cubic meters of material and bulked for analysis. A coral of 15 bulked samples were analysed , with 5 each from rhe 1 ro 2 year, 2 to 3 yea r and 3 to 4 year stockpiled material All the stockpiles consisted of anaerobically digested sludge chat had been lagooned, for about 1 to 2 years, solar dried and chen stockpiled. The samples were categorised according to the length of time chat the biosolids had been held in the maturation stockpile. Results from rhis srndy are summarised in che Table 2.

All samples were fo und to be virtually pathogen free and confirmed chat biosol ids stockpiled for more than 3 years complied

7

with the standard fo r Stabilisation Grade A. Even after l year of stockpiling the results suggested char a pathogen quality equivalent to Grade A was achieved, however viruses were found in 2 samples from the 2 to 3 year stockpile material.

Find ings from chis study demonstrated chat one year stockpiled biosolids (which had also been anaerobically digested and lagoon dried) could achieve a very high microbiological quality, even when the total solids content was lower than the current SA Biosolids Guideline requirement of 75%. le also confirmed chat biosolids stockpi led for more than 3 years complied with the standard for Stabilisation Grade A.

Conclusions T he results of intensive mo nitoring of the agitated air drying process currently undertaken at Bolivar WWTP using anaerobically digested sludge and back blending centrifuged cake equally with previously dried and processed material produces highly stab ilised biosolids at a total solids co ntent much lower than the currently requi red 75%.

Ageing the windrowed material for 60 days and drying it to at least 50% total

refereed paper

f4

solids will consisrencly produce a producr wirh E coli counrs less rhan 1000/gm.

Ir may be possible ro produce a Srabilisarion Grade A producr using che AAD process, however addirional moniroring will be required ro confirm rhar rhe required srandards fo r Salmonella and viruses are mer.

The cradirional biosolids producti on merhod of anaerobic digestion , drying in sludge lagoons and rhen srockpiling also produces a biosolids rhar is very low in parhogens.

(i(ji

Contra-Shear ' ( _ , Technology •

• More than 25 years experience in supplying screens to the Australian wastewater industry.

• We are Australian owned and operated .

• Equipment suited for both Municipal and Industrial Applications

Outcome As a resulr of rhe moniroring underraken and described above the SA EPA are inrending ro "raise the bar" fo r Stabilisation Grade B in South Australia. The South Australian Biosolids are currencly in the final scages of revision. Tc is proposed char the new standard fo r Stabilisatio n Grade Band the minimum srandard for biosolids robe used on agricul rnral cropping land , will require E coli counrs co be less than 1,000/gm T S and the biosolids ro have undergone approved vecror arcraccanr reduction treacmenr (eg anaerobic digestion). T he Agitated Air Drying process as practised at Bolivar will comply wirh the new criteria proposed, provided that the rota! solids of the processed produce is greater th an 50% and the material has aged more than 60 days since production from the centrifuge.

Digested and lagoon dri ed biosolids char has been srockpiled for ar lease one year will also comply wirh che proposed criteria wirhour furrh er resring.

Planrs where rhe sludge is lagoo ned and no anaerobic digesrion is provided (eg many of the counrry planes in Sourh Ausrralia) may have di fficul ry meeri ng rhis standard however and therefore discuss ions are still raking place with the EPA on this issue.

SA W ater and United Water are rogecher leading Australia in sustai nable and cost effective biosolids recycling and rhere has been no discharge of sludge ro rh e marine environmen t since 1994. The So uth Australian biosolids guidelines are in many ways more restrictive than chose of other scares in the co ntrols placed on application races to reuse sites and what crops can be grown on sires where biosolids is applied. The revi sed EPA guidelines rhat are soon ro be published will ensure chat on ly biosolids low in pathogen co nram inacion can be used on food chain crop prod ucing sires.

The high pathogen quality and strict controls on applicatio n race allow che responsibiliry and cost for transport, spreading and incorporation to be transfe rred from rhe biosolids processor/manager to the user. As a result the cost to SA Water for biosoli ds beneficial reuse is probably rhe lowest of any water uriliry in Australia.

Acknowledgement T he assistance of L Roder in rhe collection of samples, collation of data and preparation of graphics for chis study is gracefully acknowledged.

Reference

Technology available: Fine Screening: From I litre/sec to 3000 litre/sec

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Lane MD , Swalling D , Oem cke D, Sickerdick LM (2002) "Agitated Air Dry ing - A process suitable for la rge Australian W WTP's'" A WA Biosolids Speciality C onfe re nce, Sydney, Australia J une 2002.

www.cstechnology.com.au

The Authors Rick Desmier is rhe Biosolids Coordinaror with United Water

PO Box 82, Lane Cove NSW 2066

Incernarional , ph (08) 8259 0218, email rick.desmier@uwi.com.au;

Cliff Liston is rhe Manager Wastewater Operations for SA Water, ph (08) 8207 144 1, email cliff.liston@sawarer. com.au and Lester Sickerdick is che Principal Process Engineer Wastewater with SA

Contra Shear Technology Tel: (02) 9427 1279 Fax: (02) 9427 3354 Bamajan P/L trading as Contra-Shear Technology ABN: JS 001 226 160

Water, ph (08) 8204 1915, email lester.sickerdick@sawater.com.au

refereed paper

water

SEPTEMBER

2004 55

'SOLARMIX' - CONTINUOUS BIOSOLIDS DRYING S Nathan, 8 Clarke, N Byres Abstract The 'SolarM ix' system utilises a hothouse-enclosed drying bed; however, the most revolutionary co m ponent of the process is the complete removal of the manual labour and the "batch by batch" nature of drying beds. T he system instead works automatically and continuously with biosolids b eing auromatically loaded into one end and solar dried, stabil ised and granulated biosolids continuously disch arged at the other.

The construction and commission ing of the first 'SolarMix' facil ity at Q ueensland's Caboolture Shire (just north of Brisb ane) at the Burpengary East Sewerage Treatment Plant (BESTP) has demonstrated the potential of the p rocess for both advanced stabilisation and mass/volume reduction.

T his paper sum marises the results of the first year trials and in d icates that the process has a dramatic effect on the stabilisation of biosolids. Efficiencies in the S E Queensland climate are far better than those achieved in the numerous SolarMix systems operating in Europe.

W ith more atten tion ro ventilatio n it is plan ned ro dry the biosolids beyond 85% TSR to a pelletised form to consistently achieve Stab ilisation G rade A. Alcernacively it may be used to accelerate stabilisation in overworked sewerage treatment plants during peak load seasons, so char the biosolids consistently meet the EPA requirements for Stabilisation Grade B.

1000 . - - - - - - - - - - - - - - - - - - - - - - - - - - - ~

800

., ~

.!:

.,., i

Water lost

600

400

200

Water in sludge Dry Matter

0

15%

30 %

45 %

Caboolrure Shire is located approximately thirty minutes north of Brisbane and is currently one of the fastes t growing areas in South East Queensland.

This is an edited version of a paper presented at the AWA Biosolids Speciality Conference, June 2004. T he CD ROM for all the papers is available from the AWA office, Arrarmon.

56 SEPTEMBER 2004

water

75 %

90 %

Figure 1. Solar drying - reduction of mass.

Cabwarer, the business unit of Caboo lrure Shire Council (CSC), operates and maintains four biological nut rient removal (BNR ) sewerage treatment plants.

Currently, Cabwarer generates approximately 14000 wet ton ofbi osolid s with 15% solids per annum. Cabwacer spends approximately $600k per annum for removal and disposal of biosolids. Because of the BNR process, the sewage treatment plants are producing biosolids chat have not received su fficient treatment to achieve a consistent Stabilisation Grade B quality.

CabWater was search ing fo r a simple,

The process has a dramatic effect on the stabilisation of biosolids. Efficiencies in the S E Queensland climate are far better than those achieved in the numerous SolarMix systems operating in Europe.

Introduction

60 %

Ory so lid s content in %

Eu rop ean climate ro effectively dry and stabi lise b iosolids products on a continuous basis. In August 2003, followi ng detailed investigations, Cab Water commissioned and now operate the first 'SolarMix' facility in Australia at the Burpengary East Sewerage Treatment Plant (BESTP).

Aims T h e aim of the project was to determine the efficiency of the 'SolarMix' process ro effectively and economically dry and stabilise che unstable BNR sludge produced at BESTP ro meet che Qld EPA and NSW Enviro nmen tal G uideline requirements for Scabilisacion Grade B biosolids. T he p roject had a secondary aim ro examine if the process could also consistently and reliably achieve Stabilisation Grade A. T he effectiveness of che 'SolarMix' process was determined by moniroring che following parameters:

economic, and environmentally friendly solution co srabilise the biosolids products on a continuous basis.

• Total Solids Residue (Reduction of mass & volume) • Volatile Solids Reduction

In 2000, Mixwell Pry. Led, a firm specialised in b iosolids, had held discussions with CabWater abo ut introducing the "Solar Mix", a German based technology, to Australia. The 'SolarMix' p rocess has been implemented in Europe for well over IO years and has proven itself ro be successful in the

• Specific Oxygen Uptake Race (SOUR) • Destruction of Pathogen Populations (E. Coli, faecal colifor ms, and Salmonella)

Principles of Solar Drying Process The driving force fo r che drying process is the amount of radiation char reaches ch e b iosolids surface and the amount of

refereed paper

differential vapour pressure created. T he performance of rhe process will be optimised when the environment has the driest possible air (lowest atmospheric humidity). Ventilation is an important factor to continually remove moisrure laden air fro m rhe surface of the biosolids and replace it with fresh dry air.

- - - - - - - - Travot mo\or right

----;:_-::_-::_-::_-:._-:._-:._-:: ::.ti~7°t°' right - - - - Toothed rack Machino swildl board

Mass Reduction Figu re 1 illustrates the fact that the total mass is reduced by 50% when the dry solids conten t is increased from 15% to 30%.

Furth er, rhe total mass is reduced by 70% when the dry solids conten t is increased to 50%. Nore that the rare of mass reduction becomes lesser as percentage of d ry solids become higher.

Process Description T he 'Solar Drying' technology util ises the traditional principles of air drying biosolids bur has enhanced the process to produce a cons istent, quality controlled product.

Unlike other ' parented solar drying technologies', the 'So larMix' process does nor work on a ' Barch Basis' and instead works on a co ntinual input - continual output process. In the 'SolarMix' process, rhe dewarered biosolids are loaded either man ually or via a loading co nveyor into the front of the cell and removed via an ' in floor' load-out co nveyor at the rear of the drying cell. (Figures 2, 3, 4, 5). T he automated biosolids agitator moves along the drying cell and breaks the 'crust' fo rm ed on the biosolids (to accelerate rhe narural drying process) while formin g pellets and progressing the biosolids along rhe drying cell. As rhe product is continually turned , the product is continually aerated and does not become anaerobic and odorous. Unlike other ' patented solar drying technologies', rhe automated biosolids agitator used in the 'SolarMix' process treats the entire cell evenly ensuring rhar no biosolids escape the agitation process and therefore a consistent qual ity controlled product is prod uced. The

Travol motor loCt Rotation moÂŤor Iott

OrMng chain - - -~ Drive s h a l l - - - - - ~ Lifting m o t o r - - - - - - - - '

Rumingwhool - - - - - - - ~

Aolallondrum - - - - - - - ~

Figure 2. Dia gram of the Burpengary EastWWTP 'SolarMix' (N ote: diagram not to scale) .

hothouse can be open ended to allow narural ventilation (as in the facility at BESTP ) or ca n be entirely enclosed with fo rced ventilation to enable caprure and treatment of rhe moisrure-laden exhaust air in areas where odour is a sensiti ve issue.

The hot house is 100 merres long and 10 meters wide and it generally rakes between 18 to 28 days fo r the biosolids to proceed fro m one end to other depend ing on number of turns performed per day. On average the agitator rurns rhe biosolids 8 rimes a day and each rurning cycle rakes approximately 1.5 hours.

Design Capacity of Solar Drying Process The capacity of the 'SolarMix' process depends upon rhe floor area, evaporation facto r (moisture evaporation rare), and the

solids content required at the end of process. T he evaporation factor is also influenced by rhe type of biosolids, ambient relative humidity, number of rurns per day, and the amount of air flow through the drying cell.

T he evaporation factor is reported as the loss of moisture per square metre per day, calculated from rhe di ffere nce between rhe ingoing moisrure and outgoing moisture con tent.

Trial Results and Discussions Th ree trials were run in 2003/4.

Dewarered sludge from the belt press with ca.14% moisrure content was fed to the dryer, the daily weight being known from previous records of land disposal via semi trailer.

Figure 4a. Automatic load-out system inFigure 3. Single standard drying cel l w ith ma nual load and manual unload.

refereed paper

Figure 4. Close up of agitator.

floor conveyor at discharge end of drying cel l.

water

SEPTEMBER 2004 57

Table 1. Winter drying trial. 11 .5 wet tonne p er d a y.

No of Days In Cell

Solids Content (%) 25-Jul-03 14-Aug-03 19-Aug-03 22-Aug-03 26-Aug-03

l

Figure 5. Outside hothouse automatic loa d-out system w ith tra iler loading conveyor.

2 3 4 5 6 7

11 12 13 14 15

C urrently the system is loaded continuously in a uniform man ner. Samples are collected at 0 , 20 , 40, 60, 80, 100m points along the cell once a week and th e moisture co ntent measured.

18

Trial No 1. Winter: Rate of Loading: 11 .5 wet t/ day (4200 wet t/ annum at nominal 14% TSR In this winter trial, with a residence rime of 21 days, as shown in Table 1 o n average ca. 14% TSR sludge was dried to ca. 25% TSR at a rate of 8.1 kg of water/ metre2 /d ay.

Trial No 2. Spring / Summer. Rate of Loading: 9 .0 wet t / day (3300 wet t / annum) at nominal 15% TSR As the weather warm ed up , a trial was run with a decreased rare of loading, bur w ith a faster rare of movement, the res idence rim e of t he sludge being reduced to 17 days. As shown in T ab le 2 on average, ca. 15% T SR sludge was dried to ca 57% TSR. The evaporation facto r was calculated co b e 8.4 kg/metre 2 /day .

Trial No 3. Autumn Rate of Loading: 14.5 wet tonne/ day (5300 wet tonne/ annum) at 14.5% TSR. Throughout February/ March/ April the dryer was operated regularly at 14.5 wet tonne/day. In mid-April a campaign of sampling was re- introduced. As shown in Table 3, on average the sludge was dried from ca. 15% TSR ca. 24% TSR. T he evaporation factor was calculated as 8.2 kg / metre2 /d ay.

58 SE PTEMBER 2004

water

13.81

16.15

15.56

12.88 14.35

17.78

16.72

14.33

14.50

15.65

16.03

14.50

17.64

16.69

17.78 22.56

17.61

17.65

20.29

19.35

21.42

2 1.52

18.67 21.30 21.52 18.55 23.08 22.50

2 1.62

2 1.99

15.46 19.26

17.52 22.56

20.75 l 8. 12

24.48

24.93 18.55 26.31 23.00

22.01 21.95

16 17

22.58 24.35

21.68 22.88

19 20 21

26.27

26.32

26.39 23.86

25.00

26.52

Evaporation Factor

8.3

9.51

Average

13.41

15.51

8 9 10

In rhe first trials, wet sludge was spread onto the front of the cell. After it had been moved fo ur or fi ve meters forwa rd in a day, rhar space was loaded with fresh wet sludge.

The thickn ess of the wet sludge is now 3 00mm to 400m m during summer and 250mm to 30 0 mm during winter.

14.60

7.28

7.8

7.62

13.80 14.35 15.46 15 .51 16.26 15 .46

21.85 22.58 23.01 24.57 26.35 24.43 26.52

8.10

Table 2. Spri ng/summer dryi ng trial. 9.0 wet to nne/day.

Solid Content (%)

No. of Days In Cell

30-Sep-03 19-Oct·03 6-Nov-03 2 3 4 5 6 7

16.2 17.0 17.2 17.6

15.4 17.1 17.2 18.9 19.5

15.7 16.9 17 .7 20.3

Average

26·Nov-03 10-Dec-03 5-Jan·04 14.7 18.2 18.2 21. l 23 .8 29.1

20.4

20.5

23.7

3 1.6

8 9

20.7 25.3 30.0 34.6 42.4

33.3

25.2 26.9 29.2 32.9 39.2 56.3

35.6

10 11 12 13 14 15

22.8 25.3 26.2 28.2

52.7 60.0

30.6 39.5

16 17

66.9

59. 2

8.1

8.81

Evaporation Factor

Total Solids Residue (TSR), Volatile Solids Reduction, Specific Oxygen Uptake Rate (SOUR) Total Solids Residue Since rhe commissioning of the 'SolarMix' d rying process at BESTP in August 2003 , CabWater staff h ave b een

39.0 40.7 41.0 51.4

63.2

8.5

15.8 15.9 17.2 17.2 18.3

15.3 16.7 17.3 18.3 20.3

18 .6

22.4 23.2

20.0 22.0 24. 4 23.8 28.7 29.3 35.7

7.32

14.2 15.5 16.9 17.8

23.2 23.7 23.7 26.7

26. 1 24.4 28.0 29.9 35.9 39.9

46.3

32.4 40.7 47.0

42.9 46.7

53 .0

51.0

46.7 57.5

9.2

8.2

8.4

undergoing a study to determine the total solid s of rhe biosolids along the d istance of th e hot house.

Although there was a sligh t decline in the effi ciency of the drier in winter, ir still achieved an economical increase in TSR of the biosolids and a significant reduction in mass.

refereed paper

Volatile Solids Percent volatile solids only decreased slighcly along the drying path of the 'SolarMix' process. (Table 4). Treated dewacered biosolids usually have a volatil e solids percentage of around 68-65 as a finished produce. T he 'SolarMix' process furth er reduced the volatile solids percentage to 62.63%. le indicates chat che biosolids have stabilised and are not likely co have more rhan a 15% further reduction if incubated in a Bench Scale Reactor T esr (Table 3-3 of the NSW Environmental G uidelines).

Specific Oxygen Uptake Rate T he drying cell was sampled in autumn and Tables 4 and 5 give rhe individual SOUR results along rhe length of the dryi ng cell. They indicare a signifi ca nt decrease in the Specific Oxygen Uptake Race (SOUR) from 8.2 in the relatively fresh bi oso lids ac rhe 20 metre mark to an undetectable level of 0.49 by the 80 metre mark. This demonstrates chat the 'Solar Mix' process easily achieves the SOUR reduction required for Vector Am accion Reduction according to Table 3-3 of che NSW Environmental Guidelines fo r Stabilisation Grade B. Microbiological Populations T he 'SolarMix' process has proven itself co be an effective method of reducing the pathogen levels in the dewacered biosolids. The drying cell was sampled on two separate occasions and on each occasion, fou r separate samples were taken along the drying cell (at 20m, 40m, 60m, and 80111). T hese samples were analysed for faecal coliforms (MPN) , E. coli (MPN), and SalmoneLLa spp (p resence/absence) in accordance with T ab le 3-5 of che NSW Environmental G uidelines. Table 6 displays the results fo r the destruction of pathogens along the drying cell in the 'SolarMix' facility.

Figu re 6 (relati ng to Table 6) shows chat as the biosolids are dried and moved th rough che 'So larMix' drying cell, che microbial population is significan cly reduced and is easily able to meet the requirements of Stabilisation Grade A requirements for E. coli, faeca l colifo rms, and Salmonella spp by che 80 metre point (the co cal cell length is I 00 metres).

Table 7 and Figure 7 display the relationship between % TS R of the fin ished produce and the population of E. coli and faecal coliform.

It ca n be see n char the majority of the pathogen destruction occurs between 20%TSR and 30% TS R and by the time che produce reaches approximately 40%

refereed paper

Table 3. Autumn drying trial. 14.5 wet tonne/ day. % TSR values along the bed.

Distance From Start in Metres

Date

0 18/04/04 19/04/04 22/ 04/04 23/04/04 25/04/04 26/04/04 27/ 04/04 28/ 04/04 01/05/04 02/ 05/04

20

30

40

50

17.4

15 .2 14.9 15.2 15.0 15.3 15.1 15.0 15.0 15.3 14.5

17.0

19.8

23.0

18.6

29.0

21.8

16.6

25.6

20.0

23.5

18.0

28.4

20.9

25.8

17.5

16.9 15.5

27.3 26.1

21.5

17.3

15.9

30.4

23.4

20.2 19.1

21.0

17.5

90

25.9

20.8

17.8

15.4

80

24.8

19.2 18.8

16.4

70

60

26.8 22

18.6

Table 4. Volatile Solids and reduction of SOUR along the bed. March/April 2004 .

Volotile Solids SOUR mg02/gTS/h

10 Metres 65.5 1 2.2

50 Metres 64.24 <0.5

25 Metres 64. 42 1.6

75 Metres 64.52 <0.5

Final Product 62.68 <0.5

Table 5. Reduction of SOUR along the bed . March/ April 2004.

Date Sampled 23/03/2004 05/04/2004 29/03/2004

40 metres 1.6 12 4.3

20 metres 2.2 8.2 6.6

60 metres <0.5 3.2 2.4

80 metres <0.5 0.49 0.03

Table 6. Destruction of pathogens during drying .

Sample Date

Analyte

Units

20m

40m

60m

80m

29/03/04

Faecal Cal iforms E. coli (MPN) Salmonella spp Total Residue Moisture Cale.

Fixed Residue Faecal Calilorms E. coli (MPN) Salmonella spp Total Residue Moisture Cale.

Fixed Residue

cfu/ g (dry wt.) cfu/g (dry wt.) pres.labs. % % % cfu/g (dry wt.) cfu/g (dry wt.) pres./abs. % % %

35000 35000 absent 25.8 74.2 41.8 >86000 >86000 obsent 18.5 30.1 30.1

38000 38000 absent 23.6 76. 4 43.9 >73000 >73000 absent 21.9 34.8 34.8

1700 1700 absent 30.0 70.0 44.8 6000 830 absent 26.5 44.8 44.8

<5 <5 absent 64.8 58.2 50.7

05/04/04

<3 <3 absent 64.8 46.9 46.9

Destruction of Pathogens In 'Sotarfillx' Hothose 100000 90000

.8

ยง

z

~

:;; ~

.. .c

80000 70000

7

60000 50000

2

40000

11

30000

:i;

20000

0

10000

-~

-

. "'-...

"'-... -

0

/

7

7

.

70 60 50

-+- Faecal Collforms 2913104

--- E. coll (MPN) 2913/04

40

----

Faecal Collforms 514104

Escherichia coll 514/04 30 -w- TSR 2913/04 20 _.,._ TSR 514104

10

,._

0

Metres

Figure 6. Destruction of pathogens in the 'SolarMix' system.

water

SEPTEMBER 2004 59

TSR, rhe pathogen populations are below rhe detectable limit of 5 MPN cfu/g (therefore meeting the microbial requirements of stab ilisation grade A) .

Teething Problems During the commissioning of rhe 'SolarMix' facility, a couple of teething problems were encountered.

It was d iscovered that if the Automated Biosolids Agitator made too many passes down the drying cell (more than 10 cycles per day) rhe biosolids became ' pasty' and would nor dry effectively. When this 'pasty' biosolids was eventually dried, the product was lumpy rather than being granulated ..

Table 7. Destruction of pathogens as sludge is dried. % TSR

E.coli (MPN)

Faecal Coliforms (MPN)

17.3 20.0 22.5 26.5 28.7 29.3 30.6 39. l 41.8 64.8

92000 80000 36000 6000 1700 380 980 5 5 3

92000 80000 36000 6000 1700 580 980

It was also noticed that the number of passes and the agi rator speed had to be altered when a new biosolids product was trialed in the drying cell (i.e. from South Cabool cure STP, an aerobically digested biosolids, instead of chat from BESTP), however, once the programming parameters had been established for each biosolids product, the change-over was much easier. C hanges in the agitator programming was also needed when different polyelectrolyte was used in the d ewarering p rocess. Once these problems were overcome the biosolids were still effectively d ried in the 'SolarMix' process with no change to the quality of the end produce.

Cost Savings T he Burpengary East 'SolarM ix' facility is currently processing 15 wet tonnes per day at 15%TSR of dewatered Waste Activated Sludge during summer and 11 wet tons per day during winter.

5

5

indicated that rhe 'SolarMix' process iscan produce a dried b iosolids prod uct chat meets rhe requirements of Stabilisation G rade A accord ing to the NSW Environmental Guidelines wh en the TSR is above 45%.

H owever, further sampling and analysis will be necessary to gain enough data to satisfy the requirements of th e initial process verifi cation acco rding to the NSW Environmental Guidelines.

Even tho ugh rhe 'SolarMix' process has proven itself to work extremely well under Queensland conditions (far more effectively than in the European weather), fu rther improvements can be made to increase the dryer's efficiency and co further reduce rhe time ro dry the biosolids. Moisture droplets have been observed on the roof and walls of the 'SolarMix' d rying cell as a result of less than op timal cell ventilation and it is anticipated char a blower will increase the exhaustion of moisture laden air more effectively than the current cell which rel ies on natural air movement.

3

Since rhe insrallarion of the 'Solar M ix' dryer, operating on a proportion of rhe total sludge load , CabWater has estimated that ir will have a cost saving of in excess of 50%. In real terms, it is expected rhac the 'SolarM ix' process will remove a minimum of 2,500 tonnes of water per annum from the fresh biosolids and will save CabWater approximately $100,000 pa.

T he initial capital estimate of this project was $600k. H owever, the cost for the coral project has gone up ro $800k mainly due ro poor site condition and the introd uction of an conveyor system.

Cabwarer received 50% subsidy ($4 00k) from the Queen sland Govern ment for this project.

The Authors Senthi Nathan is rhe Operation Engineer at C ab Water, Caboolture Shire Council , email nathans@caboolcure.qld.gov.au, Tel (0 7) 5420 0705. Brendon Clarke is Operations Manager at Arkwood Organic Recycling Pry Lrd, email: arkwood@cpg.com.au, Tel: (07) 5426 3004; Nev Byres is Proprietor at Mixwell Pry Ltd which specialises in biosolids transport, T el: (07) 38 18 6888.

Conclusions The results to dare indicate char the 'SolarMix' process is extremely effective at both stabilising the biosolids and dramatically reducing the volu me and mass of the material ro be rranspo rred and reused. T he sampling regime has also

Decline In Microbial Populations with Increasing o/oTSR

Water Advertising To reach the decision-makers in the water field, you should consider advertising in Water Journal, the official journal of Australian Water Association .

For information on advertising rates, please contact Brian Rault at Hallmarl< Editions, Tel (03) 9530 8900 or email brault@halledit.com.au

100000 90000 80000 z 70000 o. 60000 ~ 50000 C: o 40000 30000 g, 20000 ~ 10000 ~

\

'fl

\

\ \ \ \

i

E. coll (MPN)

-

Faecal Collforms (MPN)

\ \

0

0

-

10

20

'

30

40

50

60

Solids Content(% TSR)

Figure 7. Decline in microbial populations with increasing % TSR.

60 SEPTEMBER 2004

water

refereed paper

DRUM DRYING: PILOT TRIALS ON SYDNEY WATER SLUDGES 8 Windschuttel, Q Tran health and environmental impacts. A mobile drying plant was hired co prod uce the granulate. The opportu ni ty was taken co trial drum drying on various types of sludge produced at some of Sydney Water's 31 ST Ps. (Eldridge et al, 2004, have reported the results of the field application trials)

Abstract An internal review of Syd ney Warer's biosol ids beneficial use program recommended that sludge drying to produce marketable granules would facili tate market diversifi cation.

Field appl ication trials to quantify enviro nmental impacts were judged necessa ry, and required the production of a stock of granulate. The opportu nity was raken co carry our drying trials on various types of sludges, using a scaled-down version of a directfired drum dryer. This paper sum marises rhe conclusions drawn from these trials.

Pilot Dryer Figure 1. The pilot dru m dryer.

Introduction Currently, all of the sludge captured ar Sydney Water Corporation's (SW C) vari ous sewage treatment plants (STPs) is stabilised, dewarered and beneficially used.

Most of SWC's biosolids (85%) is trucked co va rious sires fo r application to agricultural land. T he balance (15%) is processed in a co mposting facility.

An internal review ofSydneyWarer's bioso lids beneficial use program identified char sludge drying to produce gra nulated biosolids would facil itate market divers ifica tion.

As well as provid ing product and market divers ification, biosolids drying also red uces the biosolids product trucking coses by a facto r of three. Drying to a solids content of 92% also produces Grade A stabilised (pasteurised) produce. T his produce is essentially pathogen free.

In 200 I two Syd ney Water officers inspected a number of sludge drying installations which are being operated successfully overseas. Two of the drying instal lations inspected generate significant income from rhe marketing and sale of rhe dried produce (granulate). The Milwaukee Metropolitan Sewerage District sells 55,000 tonnes per year of dried prod uct (Milorganire) with total sales of $US ! 5 million/year in markers such as home T his is an edited version of a paper presented at the AWA Biosolids Speciality Conference, June 2004. The C D ROM for all the papers is available from che AWA office, Anarmon.

refereed paper

gardens, lawn care and golf courses. The operation of rhe sludge dryers is foc used on producing a hard, beady dusr-free produce.

Two produces are produced. C lassic Milorganire co nsists of granulate with diameters ranging from 1.5- l.6 mm and is used on golf course fai rways and home lawns. Greens Grade Milorganire ranges in diameter fro m 0.8- 0.9 mm and is used on golf course greens. New Plymouth in New Zealand has obtained certificatio n fo r their dried product (Bioboosr) as a fertiliser. T he product is marketed through a horticultural company and is used on golf courses and turf far ms. The granulate diameter ranges from 2 to 4 mm.

The drying study tour report recommended that Sydney Water's sludge drying foc us on the production of a granulate that is able to be marketed in the

A pilot drying pla nt, designed and manufactured by Flo-Dry Engineering, was used co produce dried granulate for this study (Figu re 1). This pilot dryer is a scaled down version of a fu ll size directfired drum dryer bu t preceded by manual backmixing of a proportion of dried product with fresh feed sludge. In a fu ll scale dryer this backmixing process is automated . The pilot dryer has a nominal feed sludge throughput of50 to 150 kg/hr T he feed is introduced in to a rotating drying drum by a screw feede r whose speed is lin ked to the exit temperatu re. Air heated by a natural gas burner is driven down the drum by a fa n linked co a co mbustion temperature controller, its speed being adjusted to maintain a steady set inlet temperatu re. Air inlet and outlet temperature can be set up co 850°C and l 50°C respectively. The flow of natural gas to rhe gas burner is adjusted manually to provide the necessary fuel input. Granulate temperature is measured manually by a laser

The presence of W'AS in the feed is critical for the production of a good quality granulated product suitable for the high end of the reuse market. golf course, lawn care and home garden markers. Ir was recognised that chis entrepreneurial approach co biosolids marketing focused on the high value produces offered rhe greatest potential for reco uping, in part, biosolids processing coses.

T o support this strategy field application trials were required ro quantify im pacts such as run-off effects ere resulting from application of dried biosolids co turf. A stock of granulate was required ro assess

induced temperature monitor (laser gun) char ca n record and indicate instantaneous temperature of the granulate with an accuracy of+/- 0.1 °C.

Pilot Dryer Trial (a) Trial Objectives The objectives of the trial were co: • identify what dryer operating parameters were required to produce a hard, beady and dust-free product; • identify the impact of the type of dewatered cake on product quali ty;

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• identify the impact of the solids content of the dewacered cake on produce quality; • identify the impact of the solids content of the feed mixture on produce quality.

These trials were not primarily concerned with pathogen destruction. (b) Trial Procedure The pilot d ryer was located at Sc Marys STP. Dewatered sludges (cake) from seven STPs were dried by the pilot dryer. The planes were Quakers Hill, Wollongong, Cronulla, Sc Marys, Penrith,Warriewood and Bondi,. Sludge types apart fro m Bondi STP included WAS either alone or mixed with raw primary sludge. Bondi sludge consisted of anaerobically digested raw primary. Chemical treatment uti lised in the sewage treatment processes at some planes included ferric chloride or spent pickle liquor dosing and alum dosing. Sludges were either digested anaerobically, aerobicaJly, or were undigested (Quakers H ill). Sludges were dewarered by either centrifuge or belr press with the addition of polymer.

Where possible, a range of dewatered cake with varying solids content (T SR) was dried.

T he TSR (%) of the feed mixture (i.e. the mix of dried produce and dewatered cake fed to the dryer) was also varied.

Simulations of Mi lorganire and rhe sludge from rhe upgraded Wollongong plane were also carried out. (c) Granulate Analysis T he product quality of the dried gran ulate from each dewatered cake was assessed on parameters such as roundness, hardness, size distribution, dust level and bulk density. (Figure 2) .

Results and Observations T he following observations were made: (a) Temperature Control It was observed chat sludge pellets have to be dried to a minimum TS R of92% so chat they could be preserved against biological regrowth. It was observed chat granulate with TSR of 88% experienced growth of mould after 10 weeks of storage. It was also observed chat as rhe dryer exhaust remperarnre was varied between l00°C and 105°C, there was no increase in granule output. If rhe dryer exhaust temperature exceeded l 05°C, granulates start co smoke in the drying drum. For Q uakers Hill and Wollongong sludges, it was fou nd char as the dryer exhaust temperature was increased, there was an increase in the 1.4 - 2.4 mm granule and a small decrease in the 2.4 - 4.8 mm granule. (b) Particle Size and Appearance It was observed chat dried granu le sizes were found to be influenced by the follow ing:

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Figure 2. Typical dried granules.

For Penrith and simulated Wollongong sludges, as the feed mixtu re TSR was increased there was a larger number of smaller granules, i. e. the proportion of granules in the size range 2.4 - 4.8 mm decreased and the proportion of granules in the range 1.4 - 2.4 mm increased. This is similar to the experience for the ful l scale Milwaukee plane.

For Q uaker's Hi ll, Cronulla, Wo llongong, and simulated Milwaukee (G lenfield) sludges, as the feed mixture TSR increased the above trend was reversed, i.e. rhe proportion of granu les in the range 2.4 4.8 mm increased and the proportion in rhe range 1.4 - 2.4 mm decreased.

For simulated Milwaukee (Quaker's H ill) sl udge as the feed mixrnre TSR increased there was a slight change in rhe particle size distribution, the proportion of gran ules in rhe fraction 2.4 - 4.8 mm decreased and rhe proportion in the size fraction 1.4 - 2.4 mm decreased.

Ir was fo und that as the dewarered cake TSR increased there was a larger number of smaller granules produced, i.e. there was a reduction in rhe mass percentage of granules in rhe 2.4 - 4.8 mm range and a higher mass percentage in che 1.4 - 2.4 mm range. (c) Bulk Density The bulk density of dried granules as produced in this rest was found to be in the range of 500-700 kgs/m 3• Ir was observed that the bulk density of a sample was increased as the amount of smaller granules in char sample was increased.

Thus Sc Marys sludge (5 8% granules < 1. I 8mm) produced a granule product with a bulk density of 674 kg/111 3 compared with Quakers Hill sludge (2-12% granules< 1.18 mm) which produced a product with a bulk density of 606 kg/111 3 . This variation in bulk density was probably in part due co the compaction of smaller pellets. (d) D ust Residual Duse was collected du ring the drying of several sludges. T he dust was collected from the cyclones which treat all of the drying air after it has passed through the dryer prior co release co the atmosphere. T he amount of

dust collected varied in the range of 0.25 co 3% of che coral dried granulate weight.

It is noted chat the amou nt of dust collected increased as the dewarered cake TSR was increased, eg. Penrith sludge dewacered cake (TSR 16%) produced 0.25% dust, Quakers Hill sludge wee cake (TSR 18%) produced 1% of dust while Cronulla sludge (TSR 20%) produced 3% dust. (e) Granule Hardness Hardness is measured in kPa, the pressure applied when the pellets are fractured .

However as the pellets produced duri ng the sludge trial were smaller than the head size of the penecrometer, the results may not be accurate and thus results are provided only for comparative analysis. The average hardness ranged from 80 kPa (Quakers Hill) to 237 kPa for granules prod uced from Bondi primary sludge. l e was observed char the Bondi granulates deformed but did not fracture at rhe maximum applied pressure of 320 kPa as they are very fibro us, which led to a high apparent hardness. (f) Feed Mixture TSR and Mixing Time It was shown chat the appearance and quality of dried granules is impacted by the TSR of rhe dewacered cake, TSR of the feed mixture and the operating temperatures of the dryer.

It was also found that the granu late quality also depends on the mixing time in the mixer. It was fo und char a mixing time of 20-25 minutes was required in che 60 L mixer fo r most sludges, except for rhe Bondi primary sludge which d iffered from the ocher sludges in chat it did not contain WAS and did nor conrain fe rric sludge.

Bondi sludge requi red more rime co break down during the seed ing and back-mixing process and when it did breakdown, it contained larger lumps. (g) The Role o f Ferric Chloride/WAS in Granulate Quality There was a significant difference between the granulate produced from the Bondi sludge and rhe ocher sludges. For instance: Sr Marys sludge granules are typically broken down into fine pellets, they are sharp and of irregular appearance, while Bondi sludge granules are much larger, rounder and fi brous. As a consequence, Bondi granules have a lower bulk density than St Marys granules (506 kg/m 3 vs 674 kg/ m3) .

This difference is attributed to the presence of ferric chloride or WAS. (h) General It is noted char sludges char co ntained WAS and were dewarered co T SR of approx.

18% co 20% cou ld be successfully dried in the pilot dryer (Quakers Hi ll, Wollo ngong, Cronulla, Sr Marys). The size disrriburion

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of rhe granulates flucruares wirh di ffe rent physical and chemical rrearment, as well as wirh different operating co nditions of rhe dryer. Quakers Hill sludge produces the highest percentage of 2.4 4.8 mm granulates whilst Sr Marys sludge produced a large number of smaller particles.

T he impact of WAS on granulate quality is well recognised in rhe industry. Ir is known char drying of raw sludge by itself produces a poor granulate quality including a low bulk density; however drying of a mixture of raw sludge and WAS produces good granulate quality.

T his was confirmed by rhe results obtai ned in the pilot dryer trial.

Conclusions and Recommendations T he pilot dryer was used co dry sludges from various Sydney Water STPs representing most of Sydney Water's va rious sludge treatment and dewarering processes. Fro m the results obtained, it is apparent rhar Sydney Water sludges may be successfu lly dried by direct d rum sludge dryers similar co chose employed at New Plymouth (NZ), Bran Sans (U K) and Mi lwaukee (USA).

Th e fo llowi ng are the main concl usions/ lesso ns drawn fro m rhe pilot d ryer rrial at Sc Marys STP fo r drying of Sydney Warer STP sludges: T he presence of WAS in the feed co the dryer is critical for the production of good quality granulate prod uce suitable for che high end of che reuse market. Feeding che dryer with either WAS, or a mixtu re of digested raw sludge and WAS, allows a good quality granulate to be produced. T he produce was hard, beady and had a reasonable bulk densiry (600 - 700 kg/1113) . T he produce was fo und co be suitable fo r the potential reuse marker and field resting is currently in progress.

T he pilot dryer, with its limited automation and control parameters, operated well, and prod uced a majori ty of produce in rhe usable range of 1.4 - 4.8 mm, fo r a range of different feed sludge compositions and dewarered cake TSRs, provided rhe feed sludge composition contained a majority of WAS. T his trial demonstrates the robust narnre of the pilot dryer co operate under different feed conditions co produce a usable prod uce.

Granules should be dried to at lease 92-95% T SR to be successfu lly preserved and nor affected by biological regrowth.

Ir was fou nd char generally a higher percentage of unifo rm and round granules in the target range (2.4 - 4.8 mm) were produced if dewarered cake T SR was ser at 18-20% and the feed mixrn re TSR was set at 70-75%. It is recommended char a fu ll scale dryer be designed with sufficient flexibility ro allow operation over a range of dewarered cake T SR (chis impacts on the hearing requirements of rhe dryer) as well as a range of feed mixrnre T SR. T he feed mixrn re TSR has been shown co have an impact on the produce size distribution, with different sludges shown co be impacted to a different extent.

The mixing process was fou nd co have an im pact on the produce quality. le is recommended char a full scale dryer be equipped with a specialised mixer. The dryer des ign should allow fo r easy replacement of rhe mixer co enable different mixers to be trialled throughout che li fe of rhe dryer. This is particularly important if a range of sludges is co be dried.

The following remperarnre setti ngs were fo und as optim um fo r drying sludge by the Pilot Dryer: Burner: 500-550°C Exhaust end of drying barrel: 100-105°C Red ucing rhe drying barrel rotating speed wi ll result in an increase in che d ryer retention ti me. T his method may provide benefits co hard-co-break down sludges such as Bondi, however the granule production rare would be reduced. Ir is recommended char a full scale dryer should be equipped wirh controls co enable rhe

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operator co vary rhe retention rim e. A small amount of dust was prod uced during sludge drying (up ro 3% of coral dried granules weight). A full scale dryer facili ty wo uld need co be designed co handle both rhe dust produced fro m rhe drying process, as well as rhe dust produced from the produce hand ling.

Dried granu les produced fro m SW sludges have bulk density in rhe range of 600-680 kg/111 3.

Milwaukee sludge and Upgraded Wollongong sludge were successfully simulated by mi xing dewarered sludges from Bondi, Quakers Hill and Glenfield STPs. In conclusion, granulates of a quality suitable fo r appl ication co golf courses, home gardens and horriculru re can be successfull y produced fro m a range of Sydney Water sludges. T he presence of WAS in rhe feed sludges appears co be crucial fo r achieving the right size distributio n and bulk density. Also, flexib ility in the operational parameters of rhe dryer is required to accommodate different feed sludge and co control the product characrerisrics.

The Authors Barry Windschuttel and Quan Tran are planning engineers wirh rhe Asset Management Division of Sydney Warer Corporation, Email: barry.windschu rrel@sydneywarer. co m. au References Eld ridge S M , Chan K Y, Dougherty W, Katupiriyu S. 2004 . Effec t of granulated biosolids applicatio n ro tu rf.... AWA Biosolids Speciality Conference CD RO M, WS 12.

Windschuttel B & Tran Q (2004} "Sludge Pilot Drying Project Report''.

Asset Managemenc - Syd ney Water Corporation.

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OPERATION AND MAINTENANCE OF BAC FILTERS FOR OPTIMUM PERFORMANCE P Thiel, P Cullum Abstract This paper reviews che p rocess of treatment of drinking water by Biologically Activate Carbon beds, with or without ozonacion as a precursor.

Biological Activated Carbon (BAC) Filtration BAC Filtratio n (Figure 1) is the process of utilising naturally occurring biology co remove organics from drinking water through bioassimilarion, particularly the selective removal of chose contaminants char cause taste and odour, chlorine decay, THM formatio n and biofilm regrowth in che distribution network This process is particularly desirable since, unlike normal granulated activated carbon treatment (GAC) which requires periodic regeneration or discard of the saturated carbon, the biological accivicy is continuous, as lo ng as che Figure 1. N oosa WTP BAC Filters. beds are adequately backwashed and not allowed to dry. Thus the carbon has a very long bed life, typically 10adsorb and retain slowly biodegradable 15 years. Such activated carbon filters are components char can then be biodegraded often used after treatment of the water by a by the attached bacteria leading co strong oxidising agent such as ozo ne. This co ntinuous bioregeneracion of the carbon. is a very effi cient method of treating T his allows activated carbon co be used drinking water as the oxidant stimulates the both in primary (in place of anthracite or breakdown of stable organics into a food sand) or secondary fil rrarion (after source that the biology can remove through conventional filtration) as a physical and assimilation. Water prod uced in chis way is biological fi lter media. very biologically stable and hence chlorine What Makes a Good BAC Filter? demand is low, water caste is excellent, regrowth is negligible and operating costs There is some debate as co what are reduced significantly. constitutes a BAC filter as d istinct from a GAC fi lter, however BAC fi ltration usually Activated carbon alone is also a useful media for biological fil tration due co its refers co a GAC filter that has been abili ty co remove d isinfectants such as chlorine and ozone (when chey are applied as pretreatments) relatively rapidly when comp ared co anthracite or sand. This increased rate of disinfectant destruction in che cop section of the fil rer bed w ill allow che rest of the bed co achieve maximu m biological density and subsequently higher removal of biodegradable organic matter (BOM). In addition co chis, activated carbon has the ab ility co adsorb and remove Figure 2. BAC Honeycomb Structure. potentially inhibitory chemicals and co

64 SEPTEMBER 2004 water

designed co operate in an enhanced biological mode.

Most activated carbo n filters will house biology provided the concentration of pesticides and chlorine is low in th e raw water.

However, co qualify as a fil ter op erating in enhanced biological mode, che carbon macroscructure needs co be capab le of supporting and protecting a "maxim um biological density" during backwash. BAC is only efficient wh en the carb on possesses a highly defined surface honeycomb srruccure chat allows safe si res for bacteri a co develop and be p rotected during backwash (F igure 2).

In addition co housing biology, activated carbon needs co have the ability co adsorb target contaminants co enable prolonged b iological attack by th e microbiological colony. The carbon must nor contain water soluble leachates th at may be detrimental co drinking water q uality during com mi ss ionin g such as alum inium and manganese and must not sign ificantly change the fil tered water pH.

What Determines the Bed Life of BAC? The bed life of the BAC is reached when the carbon is no longer effectively removing the target compounds it was installed co remove. Mose BAC filters are placed after ozonarion co remove ozonacion by produces such as biodegradable organic matter (BOM) wh ich is typically monitored through disso lved organic carbon (DOC) removal. BAC is an effective remover of DOC until either che adsorption capacity of the carbon is extinguish ed and/or something has happened co decrease che effectiveness of che biology.

The major even ts that contribute co the decrease in effectiveness of the bio logy are: â&#x20AC;˘ poisoning of the bacteria by superchlori nacion of che BAC, or a significa n t co ncentration of any b iological inhibitor, such as pesticides; â&#x20AC;˘ ineffective operation of che filter (such as infrequent backwashing) allowing higher life forms to over graze th e bacteria;

water treatment populations, causing a net decrease in BOM removal; â&#x20AC;˘ mineral fouling of the carbon through the biological life cycle, thus reducing the available space within the "honeycomb structure" of the carbon, resulting in a decreased biological density (usually rakes place over 15 years of filter operation).

The major events chat may contribute to the decrease of adsorption of the carbon are: â&#x20AC;˘ saturation of the adsorptive capacity of the carbon with either rhe target compound or ocher non-biodegradable interference compounds; â&#x20AC;˘ oxidation of the carbo n through chlorination or ozonacion .

Selection of BAC When choosing the besr BAC for a drinking water application, it is important co also consider the carbon's ease of commissioni ng and its particle size. T he optim um particle size for BAC is dependent upon the carbon's application and the quality of water arriving on che carbon filter bed. In primary filtration a coarser BAC is recommended to allow optimum filter run times and deeper floe penetration throughout the bed.

Typical particle size distributions for primary filtratio n are those wi th an effective size of between 1. 1 and 1.3 mm with a right uniformity coefficient to prevent pressure drop and binding with coagulants. This coarser particle size activated carbon can be easily retrofitted to existing dual media filter beds without major changes to existing backwashing and airscouring rares.

In secondary filc racion, a smaller particle size is recommended to provide greater surface area and improved physical filtration. Another benefit of smaller particle size BAC is the reduced backwash velocity required co achieve effective bed expans1011.

The optimum particle sizes for secondary filtration are chose with an effective size of between 0.5 and 0.7 mm as there is typically no concern with head loss through the bed. The smaller particle size provides a greater su rface area fo r the bacteria to utilise and therefore better performance. This particle size is also suitable fo r improving filtered water turbidity.

In drinking water treatment, che BAC should be a steam-activated, specially prepared carbon co ensure there are no chemical or water soluble leachaces, and no floating carbon during commissioning.

Figure 3. Air scour of BAC filters.

fil ters muse be shut down it is important co continue the cleaning routine co ensure the fil ters do not become anaerobic or develop large amounts of biomass. If filters are to be shut down for a number of months with no method of cleaning, the carbon should be scored dry and protected from mechanical stress. l e is important co remember chat if the filters are shut down without regular cleani ng, or if they are left co dry out, there will be a lag time in performance at recommissioning whi le che biology reestablishes.

Monitoring BAC Filters of che most important parameters, not only for con crol of head loss, bu c more importantly as the mechanism co regulate the biology on the carbon. Higher li fe fo rms such as procozoa are coo large co fir inside the protective flu tes of the BAC and wi ll be flushed away during backwash.

These protozoa would graze on the bacteria and cause a reduction in filter efficiency if allowed co proli ferate.

For optimum performance, BAC filte rs should be cleaned every 24 hours, with every three days the mini mum. Air scour plus a combined air/water stage are the most effective methods of cleaning the BAC filter, however care muse be taken co ensure there are no carbon losses. If there is not available space within the filter cell for a co mbined wash, air scour followed by water washing is generally very effective. Air scour (Figure 3) is critical co break up the polysaccharide "threads" chat the bacteria build co clump the carbon particles cogecher (Figure 4). Water washing alone may not effectively clean a BAC filter and problems such as head loss, channelling and reduced organics removal will occur.

Water washing should be at a velocity chat provides a 30% bed expansion for at least th ree bed volumes.

Shut Down of BAC Filters l e is not recommended co shut BAC fil ters down fo r long periods of time. If the

To ensure chat filters are operating effectively it is important co monitor the filte red water quality. Regular testing of the created water wi ll quickly alert the operator co any problems with the BAC filter such as drop off in organics removal or reduced filte r run times. In addition co these routine operator cesrs it is importan t co monicor che BAC for signs of mineral fou ling, particle size reduction, and adsorptive capacity, co assess how the carbon is aging. By plotting this data with time, the life of the ca rbon can be predicted and change-out scheduled long before the fil ter fails.

T o determine the biological activity of a BAC filte r the AOC (assimilable organic carbon) or BDOC (biodegradable dissolved organic carbon) of the filte red water should be monitored.

In Summary BAC filters rely on both adsorption and biological assimilation for the removal of organics. To ensure optimum performance of your BAC filters it is important co regularly clean chem with both air scour and water rinsing. Although BAC filters can be exposed co low levels of oxidants such as chlorine and ozone, superchlorinacion of the filters wi ll significa ntly reduce che carbon's performance.

Many things can affect the BAC filters life and it is important co moni tor not only the filte red water but the carbon itself co allow accurate prediction for when the carbon should be replaced.

The Authors Peta Thiel is director of Research

Operation of BAC Filters

Figure 4. Polysaccharide "th reads" and

The correct operation of a BAC fil ter is critical co its performance. Backwash is one

2000).

biology present o n BAC (magnification x

Laboratory Services Pry Led (pecarhiel@bigpond.com) which specialises in the testing and optimising of activated carbon plants, phone (03) 9437 2733.

Peter Cullum is director of Activated Carbon Technologies Pry Led (pcullum@accivatedcarbon.com.au) which provides activated carbon produces and technical advice, phone (03) 9437 2600.

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STREAM CURRENT TECHNOLOGY FOR COAGULANT DOSING Coagulant dosing would be a simple matter if influent conditions were always rhe same, bur they aren't. T radirional means of determining dosage, such as jar rests, are useful but are off-line and cannot control dosage automatically.

Streaming current technology offers a better choice.

T he Milton Roy Streaming Current Detector is an analyser which measures the net electrical charge of suspend ed particles after coagulant dosing. By sam pling after dosing, rhe SCD measures rhe charge of unreacted particles only. This can be though t of as rhe 'work nor done' by rhe coagulant.

These remaining unreacted particles will eventually be read as effiuent q uali ty, which then can be controlled by varying coagulant dosage to mai ntain a selected SCD value.

T his value becomes the SCD 'set point', which corresponds to both rhe net charge of rhe remaining particles and the effluent quality.

• sensitivity adjustment; • integrated cable or PBT (VALOX®) enclosure versions available;

The Water Business aims to keep readers alert to business news and new product releases withi n the water sector.

Media releases should be emailed to Brian Rault, brault@halled it.com .au, o r Tel

(03) 9530 8900.

• -4o to 1oo·c; • thermoplastic enclosures, integrated cable versions;

• SIS & PPS/PVDF, complete plastic loop. Overdosing or underdosing of poly mers can cause foulin g of ion-exchange resins membranes . The SCD maintains optimal dosage, el iminating this potentially expensive upset.

Industrial processes - any p rocess where cationic or anion ic chemicals are added is a potential SCD appl ication . The food, petrochemical and paper industries are fi nding the SCD to be a valuable tool for optimising t he process efficiency and finished-p roduct quality.

In short, the Milton Roy Streaming C urrent Detectors offer: • consistent effluent quality; • lower operating costs; • reduced usage of coagulants and pHcontrol chemicals; • longer filter runs; • operator alert to system upsets; • automatic control of coagulant dosing; • instan t response to changes in fl ow or infl uent quality; • chemical residuals minimised in fin ished product; • prevention of poison ing of resin bed s;

T here are several applications where the SCD is most valuable.

• decrease of sludge volume in settling basins;

Water treatment - close control of coagulants is necessary to meet drinking water standards. The Milton Roy SCD optimises the dosing of alum, ferric chloride, polymer and other coagulants.

This assures efficient control of turb idity, consistent production of high-quality water and maximum removal of Giardia and Cryptosporidium. W ith the movement toward higher water q uality standards, rhe SCD makes sense as rhe best available technology.

Wastewater treatment - the M ilton Roy SCD is beneficial in applications such as belt press, centrifuge and dissolved air flotation. The SCD constantly monitors polymer feed, permitting optimal dewarering while reducing chemical usage.

High purity water - pre-treatment systems fo r high purity water that require the addition o f a coagulant ben efit greatly from a Milton Roy SCD in the process

• continuous cleaning of the SCD probe d uring operatio n via an op tio nal Jerwash cleaning system;

66 SEPTEMBER 2004 water

• intrinsically safe, dust-ignition-proof and general-purpose optio ns available;

• handling of high-solids water or wastewater via a parented high-flow p robe.

For further information, tel Pryde Measurement Pty Ltd, Toll Free: 1800 688 211, Email: info@pryde.com.au, Web: www.pryde.com.au

CAPACITANCE LEVEL SWITCHES The Poinrek® CLS 100/200 are versatile capacitance switches with a high level of chemical resistance. They are ideal for level detection of interfaces, solids, liquids, slurries and foa m, and fo r simple pump control.

The CLS 200 offers the fo llowing features: • easy insrallarion with verification by b uilt-in LED and see-through enclosure lid; • low maintenance with no moving parts;

process connections and wetted parts.

The Poinrek CLS 200 is offered in analog and d igital versions. The switch responds to any materials with a dielectric constant o f 1.5 or more by detecting a change in osci ll ating frequency.

T he CLS 200 has the following features: • the power supply is galvan ically isolated (12 to 250 V AC/DC for analog version and 9 to 32 V DC for digital version); • level detection independent of rank wall/pipe; • high/low-gain switch covers wid e range of applications/ materials; • d igital version: integral LCD display and PRO FIBUS PA communication if required; • rigid, cable and sanitary versions avai lable.

For more information,tel: 131 773, Email: greg.smook@siemens.com.au, Website: www.siemens-milltronics.com, www.fielddevices.com

HALVING ENERGY COSTS I n fl ow machines, rhe energy consumption accounts for about a third of the operating costs. Variable-speed drive systems with frequency converters could save up to 50% of the energy in co mparison with the mechan ical control concep t often foun d here.

T he user can now have rhe amortisation rime and the expected energy saving when using the Sinamics G l50 frequency co nverter and Micromasrer 430/440 for their pump, fan or compressor calculated by a program. The program determines rhe drive system with the most suitable performance and price from the conveyed volume, height and profile of the application over rhe day and the year.

WATER BUSINESS Ir then calculates rhe energy requirements of rhe variable-speed system in comparison wirh different mechanical control concepts as well as pole-switchable motors. The positive influence of rhe speed contro l on rhe efficiency factor of rhe plant components is taken inro account.

•

T he program derives rh e savings in kilowatts fro m rhe result and converts these inro cash using rhe current energy purchase price. The energy saved, lowered maintenance costs due co plantsynchro nised operation, and the purchasing price gives an amortisation payback within months. For a typical pump drive wi th 200 kW Si namics G 150 amortises itself in six mon ths, saving more rhan Aus$3,333 per mon th.

For more information, tel 1300 369 515, Email: automationsales@siemens.com. au, Website: www.siemens.com/sinamics-g150

ADVANTAGES OF ALUMINIUM CHLOROHYDRATE Hardman Australia is a leading manufacturer of polyaluminium coagulants for water and wastewater treatment. In the past two years, Hard man has co nducted field evaluations of alternative coagulants at numerous porable water plants, res ulting in che conversio n of more than th irty plants co aluminium chlorohydrace (AJchlor AC) as a replacement for aluminium sulphate.

Alchlor is manufactured co high standards of purity compared co co nventional coagulants and is dosed in a significantly lower range. Moreover, because AJchlor is pre-hydrolysed ir does nor create acidity in che water being treated, thus savi ng on lime or soda ash additions chat are required co correct che pH fo llowing the typical al uminium sulphate treatment.

Recently, Hardman has made a significant breakthrough with rhe development of che Mulrifloc system, subscanrially improving rhe performance of alumin iu m chlorohydrace coagulant. New and more effective alumin ium chlorohydrare products have also been made available. In a recent exam pie, a 100 MLD plane rrearing dam water using 165 kilograms per hour of liquid alum and 22

kilograms per hour of hydrated lime was converted co a rrearmenr comprising a roral of 34 kilograms per hour of Mulrifloc additives, wirh alum and lime completely removed. Improvements were noted in fil ter run times, pH control, contaminate removal, chlori ne demand and coagulant cosr. An important benefi t was also observed in a halving of rhe sludge production, resu lting in a significant decrease in sludge disposal costs and pond availability.

In another alternative coagulanr eval uation at Rockhampron, Hardman was responsible fo r rhe initial full-scale trial of Alchlor as an alum/lime replacement for rhe rrearment of l 00 MLD of river water.

At chis plant, Alchlor treatment subsequently proved essential duri ng a high-w rbid icy event following srorm inundation, during which Hardman supplied bulk 25 ronne ranker deliveries ar short notice. This has led ro rhe adoptio n by this plant of alumi nium chlorohydrare treatment for high- tu rbidity co nditions.

Hardman has rhe expertise and rhe resources ro set up complete portable storage and dosing facilities for fu ll-scale trials of rhe AJchlor/Mulri Floe system in any water treatment plane. Prior laborarory investigation and ongoing fo llow-u p service is part of ch is process. Hardman is exporting the Multifloc technology ro Souch-East Asia, and has many local and overseas projects under consideration.

Forfurther information, contact Mike Owens on (02) 9624 1333 or email mike@hardman.com.au

NEW HACH UNIVERSAL CONTROLLER The new Hach Multi-Parameter scl 00 Universal Controller and Digital Sensor family reduces process mo ni toring coses and simplifies installation and operation.

Environmental & Process Technologies is selling che new Hach scl00 Universal Controller and rhe growing Digital Sensor family. T he flexible scl 00 Universal Controller will accept any two sensors in a mix-and-march arrangement from the Hach Digital Sensor Family. The selection currently available includes pH, ORP, inductive and contacting conductivity, luminescent or galvanic dissolved oxygen, turbidity, suspended solids and nitrates.

Each digital sensor is designed for simple Plug-&-Play connection, ready for operation without specialised cabling, configuration or software. As an example, potable treatment plant operators can co nnect two Model l 720E Low-Range T urbidimecers, or one Model l 720E and one digital pH sensor, ro a single scl 00 Controller.

'' Simi larly, operators monitoring various stages of rhe wastewater treatment process can use HACH LDO™ Dissolved Oxygen (DO) Probes and pH or O RP sensors in conjunction with che Solicax-sc Suspended Solids probes or Nicracax-sc N itrate probes.

Industrial process monitoring and control can benefit fro m use of dual pH or pH and cond ucciviry sensors wirh a single scl00 Controller. Hach wi ll be continually addi ng new parameters co the Digital Sensors family rhat wi ll simply Plug-&-Play to the versati le scl00.

T he scl00 Universal Controller, weigh ing only 1. 6 kg, is housed in a rugged IP66 metal enclosure with compact 1/2 DIN dimensions and is supplied with a hardware kit for surface, pole or panel mou nting. le provides operators with intuitive menu-driven software for sensor control and interface functions.

A built-in data logger scores readings fro m rhe sensors collecting data as frequently as every 15 minutes fo r up ro six months, along with cal ib ration and verification data points, alarm history and instrument sec-up changes. Analyser outputs incl ude three form 'C' alarm contacts and two independent 0/4-20 mA analogue outputs with PID functions.

Optional communications usi ng MODBUS®/RS485 or RS232, ProfiBUS DP, or LonWorks prorocols are available co provide real-ri me data ro SCADA or PLC systems. Operarors find fu rther convenience and control capability using wireless (i nfra red) data download of logged data co a Personal Digital Assistant (PDA).

Environmental & Process Technologies, in conjunction with Hach, offers technical support and trai ning as well as the instrument maintenance and service options rhar rarger the needs of nearly any facili ty and organisation.

For more information, contact the Environmental & Process Technologies, division ofBio/ab Australia, Tel 1300 735 295 or email environmentaL@aus. biolabgroup. com. In New Zealand tel 0800 422 469 or email environmentaltech@nzl. biolabgroup.com

CONTROLLING BIOLOGICAL SCUM Building on more than 20 years of experience in che design and manufac ture

water SEPTEMBER 2004

67

WATER BUSINESS telescopic bellmouths, sludge-drain valves, hand-flushing valves and groundwater relief valves.

of specialised slud ge, scum and grithandling equipment, Northside Enviromech recen tly designed, developed and manufactured five machines to control biological scum in mixed liq uor channels, fo r Sydney Water's Georges River Program.

"Key design elements incorporated in the Enviromech SkimCat scum-harvesting machines address typical problems associated with less effective scraping and skimming equipment found in the industry." said Enviromech 's M anager, Glenn Parrett. "The SkimCac machines feature full product capture and very robust non-metallic running gear fo r low maintenance and reliable service in very dirty conditions."

T he Enviromech scu m-harvesting techno logy is incorporated in a series of fixed and floating solutions for DAF systems, oxidation ditches, mixed liquor channels, sedimentation tanks and grit ranks.

The company claims that the system, which elevates the scum and pumps it to elsewhere in the plant, creates opportunities for retrofitting to existing assets without the need for prohibitive civil modifications to p rovide for gravity fl ows.

Norrhside Enviromech is a subsidiary of Norrhside Fab rications U nit T rust, a manufacturer with more than 30 years experience in che manufacture of specialised equipment for slurry handling and water treatment in the mining industry. The Enviromech b usiness was acquired by Norchside Fabrications from Coll iss Drive T echnology in 2002 after a long association between the two businesses.

Norchside Enviromech has also anno unced che signing of an exclusive agreement to manufacture and marker che well-known Fulton range of water-control gates from Gereg Sewage and Water Equipment of Sou ch Africa.

The Fulton range has been manufactured since 1965 and includes sluice gates or penstocks, channel gates, weir gates, twisd ock gates, hand-lifted gates, flap gates,

Mr Parrett stated that "the agreement with Gereg combines Northside's manufacturing efficiency and local knowledge with che extensive range and experience of one of che world's most respected sluice gate and fluid control equipment compan ies".

T he Fulton water control gates will be marketed exclusively throughout Australia and New Zealand by Northside Enviromech. "Our local engineering staff has a strong crack record in delivering tailo red, in novative equipment so lutions; and our water-gate application service is underpin ned by close technical collaboration with the highly experienced Gereg team" said Mr Parrett.

For more information about the Fulton range or Northside Enviromech scum, sludge and grit-handling solutions, visit www.northsidefabrications.com or call (02) 9981 3099.

s

CONTRA SHEAR TO HANDLE SMITH & LOVELESS PRODUCTS Contra Shear Technology (CST) and Smith and Loveless (S&L) have forma lised

Secure web-based SCADA system for monitoring and control MultiTrode has launched PumpView, a new secure web-based SCADA system aimed at municipal water authorities.

Monitoring and control of pump stations with traditional SCADA usually requires a h uge comm itment on che part of the municipal organisation d ue to its complexity, high initial cost and the related risks involved.

T he process often cakes 1-2 years to gee moving and involves signi ficant expenditure even before che fi rst part of the system is up and running. To address these issues and m itigate che risks, PumpView offers municipal SCAD A as a web-based service.

Steve Carson, Sales & M arketing Manager from M ulciTrode said, "There is no software to install, no servers to purchase, no engineers to commissio n che system and no radio repeaters. The only IT requirement is for users to have a web browser and an internee connection. There are no complexities for che municipal

68 SEPTEMBER 2004

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authority, and the first site can be up and running in a couple of hours."

Pump View puts monitoring and control back in the hands of operational staff.

M unicipal operations staff can see an overview of their pump stations network and view and acknowledge che alarms throughout che system. They can see derailed site info rmation, including levels, specifi c fau lts and accumulators. Users can reset alarms at sire and co ntrol pumps.

Alarms can generate SMS or email alerts to a number of operational staff in rotation. Alarms can be ackn owled ged via SMS or email, or via the web page.

Historical data is also stored and available to users.

The software is hosted in a secure data centre, and che use of virtual p rivate networks (VPNs) fo r communications and secure logins on the web page ensures a level of security and reliability well above the typical municipal SCADA system.

The system is priced on a persice, per-month basis and there is no requirement to commie to any contract.

The mo nthly charge includes all data comm unication over the cellular network, the software service and a n umber of SMS alarms.

To trial www.pumpview.com contact MultiTrode or your local MultiTrode agent.

For more information, see www.multitrode.com.au.

WATER BUSINESS

SCADAConnect: Connecting the Real and Virtual Worlds Water Distribution Modelling and SCADA (Supervisory Control and Dara Acquisition) technologies have evolved immensely in recent decades. A few years ago, integrating SCADA wirh a waterdistribution model such as Haescad Methods WacerCAD or WarerGEMS would have been a form idable cask due ro technological limitations. H owever, because of advances in available software, incegracion of the rwo technologies is now a realistic target.

With rhe advanced database connection rools available in Haesrad Methods WarerCAD/GEMS, iris relatively easy to sec up co nnections between rhe SCADA system and the model ro import the SCADA data.

However, this procedure requires the operator to first extract rhe relevant data from the SCADA system and place it in a fo rmatted data file. Then, the modeller must im port the data into che model. This proced ure is illustrated in Figure l.

With rhe new open database structures that are available, it is possible co establish darabase/SQL connections and retrieve data through import routi nes. However, chis option is sti ll very ri me-consuming as rhe user must create and validate SQL queries and connections, obtain special permissions (such as access or user rights ro rhe database machi ne and database) in some cases, and ensure chat rhe correct data are imported.

Due co rhe large rime requirements, importing real-rime data is nor practical with chis approach.

Recognising rhe limi rarions of the manual approach described above, Haesrad Methods developed a cool called SCADAConnecr ro establish a seamless connectio n berween WaterCAD/GEMS and the SCADA system.

SCADAConnecr works by creating ODBC direct con nections to rhe data srorage, thereby removi ng all human intervention seeps and simplifying the process to a oneclick process. Figure 2 is a schematic of chis approach.

To avoid entering rhe WarerCAD/ GEMS graphical user interface ro access the SCADA data, SCADAConnecr employs WacerObjeccs technology ro enable direct access to rhe underlying WacerCAD/GEMS database. WacerObjeccs builds customised applications for the WarerCAD/GEMS platform. In the case of SCADAConnecc, information can be auromacically queried from rhe SCADA system and passed d irectly to the WaterCAD/GEMS database, eliminating all manual processes. For example, rank levels and pump and valve settings can be automatically updated in WarerCAD/GEMS based on rhe SCADA

D Remote Tenninal Unit (RTU)

$CADA

Storage Media

Storage Media Excel/Access/Other database fcnnats

Excel/Access/Other database fonnats

Wate<CAD/GEMS DatabaseCoonactlon

Figure 1. Schematic of data transfe r from SCADA system to WaterCAD/GEMS throug h da tabase connectio ns.

Historical and Realtlme Database SCAOAConnect

WalerCAO/GEMS

Figure 2. Schematic of an a utomated im plementation us ing SCADAConnect. database, such char the next time a calculation is performed in WarerCAD/ GEMS, it will reflect the current field conditions.

SCADAConnect case study T he City of Bethlehem, Pennsylvania, has successfully employed SCADAConnect to provide their engineers with live access co real-time and historical data, resulting in the streamlini ng of casks such as: • model calibration; • model initialisation (rank levels, pump an d valve settings, ere); • real-rime estimation of pressures and flows at unmonitored locations; • decision-support during emergency situations; • reduction of energy coses; • more effective operator training.

SCADA operator interface in conjunction

with a Haestad Methods WaterGEMS water distribution model Prior co SCADAConnecc, Bethlehem's Operations Department used Bristol Babcock's OpenEnterprise sofrware as their SCADA system, and the public works department used WacerGEMS for their distribution system modell ing. However, due to security concerns, direct access to the SCADA data was limited to operations

personnel. Whenever data was needed fo r modelling, che engineers had co contact an operator who would then query the system, manually retrieve the data, and transmit rhe information to the engineer. The process was cumbersome, rime-consuming and error-prone.

SCADAConnecr eliminates these problems by establishing a dynamic link berween the rwo systems. Using the si mple SCADACon necr interface, rhe engineer creates 'signal mappings' char correlate SCADA signal names co WarerGEMS elements and arrribu res (see Figure 2). The manual process performed by the operators is eliminated, and the data query and transfer process is distilled to a single mouse click. A transaction log indicating signals char may be temporarily unavailable is also genera red.

The City of Bethlehem is not rhe only organisation ro deploy SCADAConnecr successfully. T he City of Casselberry, FL has used SCADAConnecr to link their Cirecr SCADA system with WarerGEMS. Gerald Chancellor, Water Resources Manager fo r Casselberry, said "I cannot imagine calibrating my model effectively without chis produce." He is also using the application to assist with model initialisatio n and plans to expand its use in the fu ture.

SCADAConnecr works seamlessly with all major SCADA systems, incl uding: Aspen, Citect, GE Cimpliciry, H oneywell, lntellution, Modbus, Siemens, Wonderware and Yokagawa.

More information SCADAConnecr is available now and incl udes on-sire setup service for installations of more than I 00 signal mappings.

For more information on SCADAConnect visit: www.haestad.com/scadaconnect

water

SEPTEMBER 2004 69

WATER BUSINESS an o ngoing arrangement for CST to rep resent S&L in Australia. In add ition to che wide range of screens and ocher equipment offered by Contra Shear they can now offer S&L equipment chat incl udes che world-renowned PISTA Vortex G ri t Separation system.

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For more information, tel 1300 363 707, email info@au. endress. com www. au. endress. com

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VARIABLE SPEED MIXING FOR LIQUID POLYMER FEED

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I As che original developers and designers of che Vortex Grit Separation system, the S&L Pisca is still regarded as the leader in ch is technology. The key co the Pisca success is che simple flat-bottomed grit chamber chat allows the flow pattern to be co ntrollable througho ut ics design flow parameters without che risk of shore circuiting as is commonly experienced with many alternative vortex d esigns, The flat bottom chamber is simple co construct with lower civil wo rks involved so can offer che cl ient an econo mic solutio n to gric-separacion problems. S&L guarantees grit-removal efficiencies and can package a com plete grit-separation, wash ing and dewacering process to suit every situatio n.

T his representatio n agreement means that CST can now offer an even wider range of mechanical eq uipment for both industrial and m u nicipal water and wastewater treatment plants including clarifiers, aeration equip ment, sludge d ewacering, polymer make-up systems, lime dosing, shaftl ess screw conveyors fo r screenings and sludge hand li ng, DAF, sand fi lters, and package WWTPs.

For more information, tel (02) 9427 1219.

GUIDED MICROWAVE FOR CHEMICAL APPLICATIONS Guided microwave ('radar o n a rope') offers a narrow, well-defined measurement path chat enables rel iable, contin uous-level measu rement in some of the most d ifficu lt solid and liquid application s, Ic functions consistently well in a range o f p rocess co nd itions (e.g. foa ming, turbulent surfaces) chat can co m promise the reliability of ocher level measurement principles. Until now, h owever, chis well-proven, high ly successful 'fie-and-forger' guided microwave tech nology has not been widely used in the chemical industry because the exotic metals used for guided radar prob es in corrosive chemical p rocesses have been signi fican tly more expensive than standard 3 16 stainless steel alrernacives.

70 SE PTEMBER 2004

Endress+Hauser's Applicator Selection software cool at www.au.end ress.com can help customers explore their levelmeasurement options an d determine exactly which Levelflex FMP4 1C model chey need.

water

T he new Level flex FMP41 C from Endress+Hauser is che only guided microwave technology chat offers rod and rope versions 100% encased in corrosionresistant plastic materials, Ocher probes on the market chat fea ture plastic (e.g. PTFE, PFA) coating also incorporate a metall ic component b uilt from exotic, highly expensive materials like titanium or Hascelloy C chat withstand the corrosive chemicals in the p rocess. With Levelflex FMP4 1C, che process only comes into contact with suitably certifi ed coatings providin g a reliable, corrosion-resistant, lower-cost measurement solution fo r chemically aggressive applications, The FMP4lC incorporates an industry standard time-of-fl ight (ToF) user interface for quick and easy sec- up and operatio n.

Sec-up and predictive maintenance can be readily performed at che measuring point using che fou r-line, SO-character local d isplay; or remotely using the ToF Tool sofrware (supplied free of charge with the FMP41C). Boch che local display and che software offer intuitive operat ing menus using p lain English text. There is no need co loo k up parameter codes or matrix positions in a paper-based reference manual, because the user simply selects and enters relevant variables from a pre-defined list coverin g all types of process conditions, Furthermo re, two of th e fo ur lines in che local display contain explanatory text, which in the ToF Tool software is expanded wich links to che relevant H elp chapters.

As with all models in Endress+Hauser's time-of-fl igh t range - ultrasonic, radar and guided radar - the emphasis on ease of use extends to modular design and userexchangeable components, In both che rod and rope versions of che Level flex FMP41 C, even che encapsulated probe can be exchanged by che user in five minutes or less, The Levelfl ex FMP41 C has a SIL 2 racing in accordance wich IEC 6 1508, which makes it che only SIL-rared measu ring device of its kind, le is available in both two- and fou r-wire versions . A cho ice of HART, Profibus PA and Foundation Fieldbus digital output protocols enables simple integration inco existing systems.

USF Scranco offers the PolyBlend® M Series liquid polymer feed system to handle che liqu id/solid separatio n needs fo r wastewater treatment applications.

The M Series comb in es USF Stranco's motorised mixing technology with precise controls, a variety of pump offerings and an easy-co-service system open-frame design ,

Two unique optio ns have been added: variable speed mixing and automatic dosage control w ith constant solution strength co meer a wide range of po lymer feed application requirements. The M Series is designed co handle new polymer develop ments, ultra-high molecular weights, different charge densities, and even totally new chemistries, A constan t-speed motor is standard on che M Series and optio nal variable speed d rives are available co accommodate application or technology changes. As polymer needs change and as new polymers are developed, the M Series can be quickly fi eld adapted, T h e M Series outpu t can be adjusted remotely via 4-20 mA signal or righ t at the unit, water flow and polymer feed increase an d decrease together, automatically maintaining a constant solution strength .

Primary and secondary d ilution water are kep t at the same ratio as o u tp ut is ad justed.

The M Series uses USF Scranco's multizone mixing, T h e first zone exposes the polymer co a h igh-energy environ men t co minimise agglomeration, Redu ced mixing energy in che second zone p rotects che fragile polymer chains from fracturi ng making more polymer available for work, T he baffling is designed co create a capered mlXl ng regime .

The six sizes cover ou tput ranges from 0.03 co 750 LPM, and th ere are 14

WATER BUSINESS diaphragm , gear or progressive cavity polymer pum ps co choose from.

For more info rmation contact Tim Batt at USF Stranco on (02) 9850 2822 or tbatt@usfcom. au

SLUDGE DEWATERING TECHNOLOGY AT BROOME STP CRS I ndustrial Water Treatment Systems recen tly provid ed its G eo tube® sludge

weather serried and the infrastructure was fina lised , pumpi ng of the firs t of 16 Geotubes® began on 16th May 2004.

dewatering technology co G endredge (WA) P/ L for containment and dewatering of 25 ,000111 3 of sewage sludge at WA W ater Corporation's Broome Sewage Treatment Pl ant.

Using Gendredge's unique continuous loop unmanned 150mm hyd raulic dredge, pump ing of the 5% solids sewage sludge was undertaken for 12 hours a day over the ensuing six weeks. Polymer, dosed at ~ l00ppm , was added co the sludge in-line, prior co containment and dewatering in the

T he project was initially ham pe red by a series of cyclo nes and the rropical 'wet', making the earthworks involved in the creation of bu nd s and pump sumps a d iffi cult and lengthy process. Once the

Stand-alone datalogger saves on groundwater monitoring Frequent monitoring of soil and groundwater quality is traditionaUy a labou r-intensive job. T his is also rl1e case if saltwater intrusion or poll ution at remediation sites needs co be monitored.

H owever, the new CTD-Diver of Van Essen I nstruments is a fu lly stand-alo ne datalogger with built-in memory, battery and sensors. I ts ceramic casing and conductivity measuring range (0-80 mS) make the CTD-Diver suitable for use at every measuring site.

The CTD-Diver is impervious co the most aggressive substances found in water environments. Its ceramic casi ng resists when even the stron gest metals yield. I t is a highly rel iable, compact d atalogger for the simu ltaneous measuring of groundwater level , temperature and co nductivity.

These parameters are measured at time intervals predetermined by the user. T he measured values are stored in the d atalogger's memory and can be read our at any given time.

Programming To program the CTD-D iver, it should be connected to a computer via a USB or RS-232 port. Programming th e CTDDiver takes only a few minutes in the field or at the office. Location, start time and samp le rate can be entered. The user can also choose a fixed or an event-based samp le rate. In the latter case, measu red values are scored only if conductivity changes occu r. A typical example is the increased pollution (conductivity) caused by an illegal discharge. The CTD-Diver can start measuring at any time you specify.

Measuring The CTD-Diver h as three sensors: a pressu re sensor to measure water level, a temperature sensor, and a four-elect rode sensor co measure conductivity. The internal memory can store up co 16,000 measurements fo r each parameter. All readings are date an d time-stamped.

Readout With the use of a Direct Read Cable™ (DRC) and the DiverMate'™ hand-held data-transfer unit, the CTD-Diver data can be disp layed without removing it fro m the monitoring well. The D iverMate is connected to the DRC, which is connected co the CTD-Diver, at the top of the monitori ng well. Data can be retrieved from several CTD-Diver units, which can later be transferred to a compu ter.

T he CTD-Diver is supplied with the Logger Data Manager (LD M) software package. This software is easy to use and offers add itional feat ures such as a barometer wizard to compensate water level measurements for cl1anges in ai r pressure. LD M also includes a calibratio n wizard for q uick and easy conductivity sensor cali bration. The data is stored on you r computer and can be exported i11 various formats co a spreadsheet program or database.

Models The CTD-Diver is available in three models with different pressure measuring ranges (1 0 , 30 and 100 m water column).

All models have a conductivity measuring range of 0-80 mS/cm.

The CTD-Diver has a new ceramic casing chat is rugged and practically corrosion-proof. T he installed CTD-Diver cannot be seen above ground level, which keeps the risk of vandalism co a minimum.

U nlike many other systems, the CTDDiver d oes not need a vented cable leading to the surface. The system is entirely closed and moisture penetration is impossible.

D epending on th e use, the battery will last for approximately eigh t years. All you have to do on site visits is rinse the Diver including sensors and calibrate conductivity. This is easily done using the

LDM software and standard calibration solutio ns. The CTD -Diver can be rei nstalled in the mo niroring well and resumes its work. A BaroDiver™ daralogger should be used simultaneously to measure variations in air p ressure so chat this can be compensated for when analysing th e CTD-Diver data.

Applications • Aqui fer storage and recovery projects • Salinisatio n projects • Saltwater intrusion projects • D ischarge monitoring • Monitoring landfill sites • Monitoring groundwater and surface water.

Benefits • Three sensors in on e sealed, corrosio nresistanc ceramic housing • Frequent, lo ng-term measuring withou t h uman intervention • Reliable and accurate measuremenc data • Easy calibration • User-friendly software, including various export for mats.

Specifications • C ompact size, 22 mm diameter and 183 mm lengrli, fo r easy handling and installation • Ceramic housing • Conductivity range 0-80mS/cm • Level range 10,30, 10Om • T emperature range - 20 to 80°C • Accuracy 0.1 % • Communication USB or RS-232 •

Battery life typically 8 years.

For more detailed information please contact Adam Merhab on (02) 9894 4511.

Email sales@aqualab.com.au or Web www. aqua/ab. com. au

water

SEPTEMBER 2004 71

WATER BUSINESS GeotubesÂŽ. The solids concentration of the sludge was increased from 5% to 35% over the initial 60-day settlement period.

Georubes proved to be a robust, eco no mical solution to the difficulties normally experienced when dewatering large pond volumes of sludge in remote subtropical locations. Manufactured from high strength purpose-designed georexrile incorporating a patented circumferential stitch , Geotubes can be used for containment and dewarering of a ran ge of fine-grained sediments and sludges.

C RS has had many installations in the water industry including the treatment of water (alum and ferric) and wastewater (municipal and industrial) sludges.

For more information contact Bill Kelly at CRS on (02) 9899 7811 or go to www.watertreatment.net. au and see under the products category.

TONY HOURIGAN JOINS ALLDOS Alldos O ceania has appointed T ony Hourigan as Regional Manager fo r Victoria, South Australia and Tasmania. He was previously with Acromec Australia.

H e will support the existing Alldos customer and distributor base in the southern states, as well as the further development of these key markets.

of the inaugural inductees of the inextricably obstructed tap society (I.D.I.O.T.S) in reco gnitio n of his commitment and active promotion of the association's vision and philosophies.

His main activity h as been in the water and wastewater ind ustry, and he has been working with both the operators and management of water authorities and councils all over Australia and Asia Pacific.

The Alldos product h as been represented and distributed in the region for nearly 20 years and end users include municipal water authori ties, power, mining and many industry sectors for products such as metering p umps, gas chlorinators, measurement and control instrumentation, chlorine d ioxide generators, and dosing systems as well as a wide range of chemical dosing skids.

Al/dos Oceania Pty Ltd was established as wholly owned subsidiary ofAl/dos International AG in October 2003 and began operations 1st ofJanuary 2004. For further information please contact Tony Hourigan on 0437 042 284 or the Alldos head office (07) 3712 6888.

BIOSOLIDS ODOUR CONTROL A safe nitrate salt solution can eliminate odour p roblems from biosolids handling operations. Offensive odour is generated in biosolids by the anaerobic activity of bacteria in much the same way as in the sewage collection system .

H aving used up all the available oxygen, sulphate is usually the next best thing resulting in the production of hydrogen sulphide and a variety of other reduced sulphur compounds [RSCs].

T he option of replenishing che oxygen by agitation or mechanical mixing is generally too expensive to consider. Dosing with sodium hyp ochlorire can be an effective remedy but is expensive and the chemical is potentially hazardous .

The safe and economical solution may be to add solutions of nitrate salts to che sludge or biosolids maintaining a stable level o f nitrate to satisfy the biological oxygen demand of the micro-organisms present.

Tony H ourigan began his career in the water treatment sector with Wallace and Tiernan, joining it in 1994 as Service and Sales Engineer. He joined Acromet in 1998 as Product Manager Chlorination with a direct go al of introducing new product to the market.

N itrate is generally used by bacteria as an oxygen source in preferen ce to sulp hate.

C olourless, odourless, non -corrosive nitrogen gas is generated in this process rather than toxic, evil-smelling hydrogen sulphide. When nitrate is mixed in completely, naturally occurring bacteria in the sludge or biosolids w ill also consume existing sulphide and RSCs.

He h as been a member of the Water Industry Operators Association (WIOA) fo r many years and, in March this year, was one

Experience has shown that an additio n rare of 0.3% per wet tonne of biosolids will deliver effective odour control. As the

72 SEPTEMBER 2004

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nitrate is readily co nsumed by bacteria, residual nitrate levels in the b iosolids are not increased.

W hil st th e use of nitrate will nor remove all odour associated with the biosolids stream , remaining odours are generally accep table ro operators and landfill staff.

The nitrate solution used, typically calciu m nitrate, is classified as nonhazardous and can be stored and handled safely without the need for expensive infrastructure and equ ipment.

Application of the nitrate solution can take place at various phases of the biosolids thickening p rocess. For odour control during transport and storage the solutio n is typically sp rayed onto thickened biosolids and mixed in when the solids are loaded onto trucks or transferred into storage ranks .

The solution can also be added earlier in the thickening p rocess into centrifuges and presses.

For more information on the use ofnitrate in controlling biosolids odour, contact John Williams at USF Wallace & Tiernan on (02) 9850 2800 or john. williams@wandt.com. au

AUTODESK OFFERS NEW INFRASTRUCTURE ASSETS SOLUTIONS Autodesk has announced new solutions that h elp local governments and water utilities create, manage, and share their CAD , GIS and engineering information in a single, open-standards enviro nment providing seamless integration to enterprise applications.

These solutions extend the user's ability to integrate data types and share information across organisations - from planning and design to operation and maintenance of infrastructure assets - to ensure accuracy, precision, and data integrity are maintained.

"We are offering large and small government departments and utilities a simple-to-use, affordable solution with an open environment chat gets them up and running quickly, and continues to leverage their existing investments in all types of data," said Chris Bradshaw, Vice President of Autodesk's Infrastructure Solutions Division.

"Customers no longer have to create in a CAD or design area, export che data into a GIS system for management and then cry, often unsuccessfully, to re-import it into the original system."

The Autodesk local governmenr/ucilities solurion includes modularised applications, such as sewer, water, cadascral, roads, drainage, electricity and map books for infrasrruccure data capcure and spatial data

WATER BUSINESS management. The applicarions are buil r on Aurodesk Map®, Aurodesk MapG uide®, and Aurodesk® Land Deskrop sofrware.

T h is allows Aurodesk users ro expand on rheir currenr sofrware investment. The soluti on is integrated wirh leading OpenG IS-compliant objecr-relarional darabase delivering complex spacial data analysis. Modules work rogerher or as srand-alone sofrware, delivering to users rhe specifi c fu nctionaliry they need. The modules provide a common set of tools for mainraining, editing and distributing data, while ensuring dara accuracy, regardless of format.

In order to offer these solutions, Autodesk collabo rated wirh Munsys Technologies, a long-rime Autodesk parrner and a provider of enrerprise spacial solurions for local governments and uriliries.

T ogerher, Autodesk and M unsys combine imporrant features char rhey once offered separarely to local government and urilities. Custo mers will now receive leading-edge Munsys technology, built for local governments, running on the industry-standard Autodesk technology that they know.

In the Asia Pacific region they are delivered through Open Spacial Technologies based in Sydney, Australia, chat had recently secured a three per cent market share in the local governm ent GIS market segment (source: Corporate GIS Consultants 2004 survey) with their implemenrations at Mid Coast Water and Goulburn Valley Water.

Both these early adopters have, over the past rwo yea rs conservarively reported 100% ROI within 6-9 months of implementation. "Of a number of projects char we are conducting, Munsys has been one of our success stories... we have backed a winner" said Peter Qui nn, Directo r Corporate Services at Goulburn Valley Water.

"We're pleased char Autodesk has taken Munsys to che next level in the United Scates and Canada. Th is is confirmation to our custo mers chat their selection of Munsys is being acknowledged by the world's largest digital conrent company" said Anthony Jahshan, Managing Director at Open Spacial T echnologies.

For more information about Open Spatial, including integrated consulting and training, see www.openspatial.com.aulnews. For more information about Autodesk and partner solutions for local governments, see www.autodesk.com/localgovernments.

TRIWATER FORMED TO FOCUS ON BNR MARKET On 1 July 2004, Triwater Australia Pry Lrd was formed rhrough a partial management buyout from Simon Engineering (Australia) Pry Led (SEA) . Ac the same ri me, Aeroflo Pry Led, merged with the new Triwacer business.

Triwacer has been formed to provide a greater focus on the design and construct of a wider range of biological nutrienr removal - BNR - sewage and industrial wastewater treatment projecrs, tackling projecrs up to $5 mill ion in value and servicing co mmunities of up to l 0,000 people.

SEA itself will continue to deliver larger projects, and T riwacer will provide process design support and equipment to SEA for these larger BNR plants.

Triwarer wi ll have a srrong ream to focus on the emerging water reuse marker particularly in SA. In addition, via its wholly owned subsidiary, Triwater UK, it will undertake BNR projects in the UK marker in co njunction wirh irs UK joint venture parrner, Copa Limited.

T he Triwarer team will contin ue to offer the sa me service as the market currently receives, togerher with rhe addi rional benefirs associared with a small team of specialist profess ionals focus ing solely on wastewater treatment and wastewater reuse projects bur with parricular emphas is on three elements: value, innovation, and service.

The T riwacer ream brings rogether decades of experience albeir rrading under differenr names, includi ng Aeration and Allied T echnology (MT); Tu bemakers Water Treatment; Henry Walker Enviro nmental and Simon Engineering.

Ray Anderso n, who was the original Managing Director of M T , will be the new Managi ng Direcror of T riwarer. Graham Furber will be rhe General Manager Southern and David Potter will be che Business Development Manager.

Ifyou have any queries regarding the new company do not hesitate to contact: Ray Anderson on (02) 8707 7700, Email ray.anderson@triwater.com.au; Graham Furber on {08) 8370 3 130, Email graham.furber@triwater.com. au; David Potter on (08) 8370 3 130, Email david.potter@triwater.com. au

FACILITIES MANAGEMENT SOLUTION Water utilities face tighter informarion technology budgets, reduced in-house development staff, and rhe need to deliver business benefits quickly through applications. ArcFM is offering a complete solutio n for facili ties management, and is

designed ro meet the needs of the water indusrry.

ArcFM is a powerful extension co ESRI's ArcG IS platform, and is a complete enterprise utiliry solution for editing, modell ing, mai ntenance and management of fac il ity and land-based information for water, wastewater and srormwacer utili ries .

ESRI's ArcFM rakes advantage of an industry-srandard archirecture and programming environments, an easy-to-use interface, and powerful carrographic tools, giving uriliries in rhe warer marker an optimised solution fo r the entire organisarion.

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The ArcFM solurio n offers proven software tools and strategic opportunities to use GIS throughour the utility organisation.

Keeping viral inform ation on assers, clients and potenrial customers up to date and readily accessible across an enterprise provides a major co mpetitive advantage in today's marker. W ith ArcFM, utilities can provide in formarion to the right people at the right ti me, creating better work processes and closer ties with customers.

To take advantage of ES RI Australia's Early Adopter Program for Water Utilities, purchase rwo licences of ArcFM by 31 March 2005 and receive 50% off the coral price of che two licenses.

For more information contact ESRI Australia on 1800-GJS-J l l or email gissolutions@esriaustralia.com. au

CLEANER USES RECYCLED WATER W ater recycling technology fo r sewer and drain-cleaning operations has been much im proved in recenr years. Developed in Europe, where water co nservation is an economic, environmental and political imperative, chis important technology resulted in subsrantial productiviry increases whilst, at the same time, conserving precious water. Specially developed highpressure transformer pumps use strained raw sewage as the cleaning medium, thereby eliminating the need to use drinking water.

Particle sizes of up to 0.5 mm are said to be tolerated by these pumps. The manufacturers claim these pumps no longer need filtered flui ds - bur merely a strai ning process to remove the larger contaminants.

water

SEPTEMBER 2004 73

WATER BUSINESS Reducing pump water preparation to a simple straining process totally eliminates che expensive and labour-intensive filter maintenance required by conventional piston pumps, which are said to be highly sensitive to contamination.

Mose importancly, ic is claimed chat the on-board water recycling process eliminates the need co stop cleaning production for refilling purposes (which can be very timeconsuming) thereby nearly doubling productivity of recycling combination jet/vac machines. Some operators of highperformance combination recycling machines claim p roduction increases of 50 to 90% over co nventio nal, non-recycling combination cleaners, easily offsetting che additional purchase costs.

New fixed and rotating cleaning nozzles and tools have been developed specially for contaminated recycling water and to wichscand highly abrasive and corrosive cond itions. Precision ceramic inserts and seals further improve cleaning efficiency and p revent excessive nozzle wear.

Authorities point to p rolonged drought conditions and ongoing water restrictions as clear evidence for che u rgent need to safeguard and conserve water. It is estimated that m illions of dollars of taxpayers money will be spent to encourage the public to 'save every drop'. H owever, au thorities will need to examine their own (or their contractors) drain cleaning procedures to avoid che daily wastage of megalitres of valuable drin king water in the cleaning of our sewers and drains.

For more information, contact Kurt Jaks tel (03) 9543 8722 www.sewerdrainclean.com

LATEST HURRICANE VENTILATOR REDUCES OXIDATION Edmonds commenced business in a small workshop in Syd ney's Crows Nest in 1934 where Neville Edmonds, a young engineer, patented and began manufacturing che now famous S Rotor Ventilator.

In 1985, Edmonds released the Hurricane Turbine Ventilator which has a u nique vertical vane design which considerably increases ics exhaust capacity over traditional spherical vane vent designs.

The H u rricane Turbine Ventilator has been specified by both Queensland Proj ect Services and N ew South Wales Department of Public Works .

74 SEPTEMBER 2004

water

In 200 l , after consulcacio n with Queensland water councils, Edmonds scarred manufacturing che Hurricane S2 Ventilator. The Hurricane S2 was specifically developed to help reduce the race of oxidation and degradation of sceel roofi ng over water storage reservoirs. The Hurricane S2 is also widely used for venting sewer pipes and composting toilets Australia wide .

T he Hurricane S2 is a purpose-built T urbine Ventilator which includes the following sizes H lO0, Hl5 0, H30 0, H400 , H 450, H500 and H 600.Each ventilator is powder-coated insi de and out, and contains a deflector flange located beneath the main bearing. This bearing is also located above the top place of the vent to reduce exposure to harsh vapours. This ensures a longer life wh ich is not possible with normal spherical shaped ven ts.

Since the introd uction of the Hurricane S2, several councils throughout Queensland have replaced spherical-shaped ventilators o n existing water reservoirs with the Hurricane S2. Users include Townsville Water, Logan Water, Redland Water, Gold Coast Water, Ipswich Water and Tweed Shire Counci l.

For more information, tel (07) 3272 5455.

RAINWATER TANKS A VITAL PART OF SUSTAINABLE URBAN DESIGN The Roda ecoRain速 rainwater utilisation system is playing a crucial role in a display site set up to demonstrate the principles of water-sensitive urban design (WSU D).

Visitors to the si te can see operating solutions chat integrate sustainable water management into urban development. The WSUD ph ilosophy is based on managing the total urban water cycle and reducing demand on potable water supplies.

A critical aspect of WSUD is che retention, improvement and reuse of stormwater runoff. Design components include rainwater tan ks, bio-retention systems, grass swales, vegetated filter strips and permeable pavements.

T he demonstration sire, at Model Farms H igh School in Western Sydney, is

managed by che Upper Parramatta River Catchment T rust (UPRCT) and funded by the NSW Government's Stormwater Trust, che UPRCT and Sydney Water.

Model Farms High School, which specialises in agricultural studies, p rovid ed an ideal setting fo r a demonstration of WSUD .

Stormwater is gathered by bio-filtration trenches and stored in Rocla ecoRain速 underground tanks for reuse.

The water also passes through the inbuilt filter of the ecoRain速 system before being stored in the tank.

T wo 10,000-licre Roda ecoRain速 underground tanks are installed at the site, storing stormwater that is pre-filtered by grass swales and bio-retention trenches before passing th rough the system's inbuilt fil ter. The water is then p umped back for irrigation of educational crops and a spores field.

Samples of stormwater were taken before retrofitting the WSUD systems to allow monitoring of levels of nutrients, heavy metals, sediment and bacteria in che runoff.

The University of T echnology Sydney is undertaking the comprehensive monitoring program.

The Models Farms High School site is o ne of a series being created across Sydney to educate the wider community in the benefits of sustainable urban develop ment.

For more information, contact Roda on 131 004, www. waterquality.rocla. com. au