Page 1


Volume 24 No 5 September/October 1997 Journal Au stra lian Water & Wa stewater Association

Editorial Board F R Bishop, Chairman B N Anderson, G Cawston, M R Chapman P Draayers, W J Dulfer, GA Holder M Muntisov, P Nadebaum, J D Parker A J Priestley, ] Rissman

General Editor M argaret M etz AWWA Federal Office (see address below)

Features Editor EA (Bob) Swinton 4 Pleasant View Cres, Glen Waverley Vic 3150 Tel/Fax (03) 9560 4752

Branch Correspondents ACT - Ian Bergman Tel (06) 248 3133 Fax (06) 248 3806 N ew South Wales - Mitchell Laginestra T el (02) 9412 9974 Fax (02) 9412 9676 Northern Territory - Bill Bean Tel (08) 8924 7201 Fax (08) 8941 0703 Queensland - Tom Belgrove Tel (07) 3810 7967 Fax (07) 3810 7964 South Australia - Peter Marrin T el (08) 8303 8723 Fax (08) 8303 8750 T asmania - Ed Kleywegt Tel (036) 238 2841 Fax (036) 234 7109 Victoria - Mike Muntisov Tel (03) 9600 1100 Fax (03) 9600 1300 W estern Australia - Jane Oliver T el (09) 420 2462 Fax (09) 420 3178

CONTENTS From the Federal President ....................... ... ....... ...... .. ... .... ......................... .. 2 From the Executive Director ....... ..... ... ..... ..... .... ............ ... ...... ... ..... ..... ... ........ 4 MY

POINT

OF

VIEW

Biodiversity-We Depend On It

A Jones ............ ........ ......................... ..... ................. ............. ......... ... ........ ..... ..... 3 INDUSTRY

PEOPLE

Profile-Sandra Burke

C Porter ... .. .. ..... ............... .... ..................... ...... ............... ... ..... ... ...................... .. 6 WATER Needs, Challenges and Health Benefits of Drinking Water

R H elmer ......... .......... ............... ....... ... ...................... ........ ............... ... ...... .. .. .. 10 WATER

QUALITY

RESEARCH

From Catchment to Tap-Supplying Affordable, High-Quality Water

Bursill, T Priestley .... .. ............. ... ..... ... .... ..................... .......... ........... ................ 13

Advertising & Administration

Recreational Water Guidelines for Cyanobacteria

AWWA Federal Office Advertising: Anne Adams Graphic Design: Elizabeth W an PO Box 388 Arcannon NSW 2064 Level 2, 44 Hampden Road, Arcam1on Tel (02) 9413 1288 Fax (02) 9413 1047 Email: awwa@inta.net.au

L S Pilotto, M D Burch .. ..... .............................. ............... ........ ......... ... .. .......... 17

Water (ISSN 0310 ¡ 0367) is published six times per year: January, March , May, Ju ly, September, November by

Australian Water & Wastewater Inc ARBN 054 253 066

Federal President Mark P ascoe

Executive Director Chris D avis Australian Water & Wastewater Association assumes no responsibility for opinions or statements of facts expressed by contributors or advertisers and editorials do not necessarily represent the official policy of the organisation. Display and classified advertisements are included as an inforn1ation service to readers and are reviewed by the Editor before publication co ensure their relevance to the water environment and to the objectives of the Association. All material in Water is copyright and should not be reproduced wholly or in part without the written permission of the Editor.

Subscriptions Water is sent to all members of AWWA as one of the privileges of membership. Non-members can obtain Warer on subscription at an annual subscription rate ofS39 (surface mail).

Blue-green Algae and Drinking Water Quality

D A Steffensen, B C Nicholson, MD Burch, M Drikas, P D Baker ...... ....... ... 19 Beyond Collforms-Measurlng Human Health

ME Hellard, M I Sinclair, G Ranmuthugala, LS Pilotto , A Padiglione, B E Robertson , C K Fairley .................... .. ....... ... ........... .. .. ... .... ..................... .. 26 Natural Organic Matter- The Curse of the Water Industry

M Drikas ... ................ .............. ..... ... ....................... .. ................. ..... ....... .... ...... 29 Predicting and Maintaining Drinking Water Quality in Distribution Systems G Kas tl, I Fisher ............... .. ...................... .... .... ..... .......... ....... .......................... 35 WASTEWATER Biological Nutrient Removal- Present Status and Future Directions

J Keller, K J Hartley ........ ... .............................................................................. 39 ENVIRONMENT Sweet Smell of Success for Odour Interest Group

M Laginestra .................... ....... ..... .. .......................... ......... ............................... 41 BUSINESS A Quantum Increase In Wate r Prices

J Crockett, L Carroll ........................... ........... ............. .. .. ........... ... ............ ... .. .. 43 DEPARTMENTS International Affiliates .......... .... .... .... .............................. ...... ........... ............. 8 From the Bottom of the Well ......................................................... ........... ..... 2 Meetings ........... .. .. .... ... ........... ..... ...... .... ..... ... ............ .... ..... .. .... ..................... 48 New Products ...... ... ........ ....................... ........ ............. .. ..... .... ... ................... . 47 OUR COVER : Clean W ater for Future Generations The CRC for Water Quality and Treatment carries out research, education and training aimed at assisting the Australian water indust1y to supply clean, affordable water for present and future generations. Photograph by Wendy Easton of her son, Giles, aged 4. Photo courtesy of CSIRO Molecular Science (formerly Division of Chemicals and Polymers), a participant in the CRC for Water Quality and Treatment.


WATER

NEEDS,CHALLENGES AND HEALTH BENEFITS OF

DRINKING WATER R Helmer Abstract The global situation in the area of water and health is characterised by large population groups in developing countries which are excluded from adequate supplies of safe drinking water and from suitable sanitation services. The resulting diseases are most prevalent in areas of rural and urban poverty. Improvement in water supply usually includes disinfection by chlorine. Related risks and benefits of a chemical and microbiological nature have to be assessed in comparison. The World Health Organization (WHO) Guidelines for Drinking-Water Quality provide the basis for risk assessment and management. They also cover the setting and application of national standards.

Key Words Chlorination, developing countries , disinfection, disinfection by-products, drinking-water quality, health risk assessment, infectious diseases, urbanisation, water resources

Introduction The Mar del Plata Action Plan, adopted by the United Nations Water Conference in 1977, already stipulated that 'all peoples, whatever their stage of development and their social and economic conditions, have the right to have access to drinking water in quantities and of a quality equal to their basic needs' (United Nations, 1977). This gigantic task of providing all peoples with their legitimate share of potable water must be tackled on three battlefields: hundreds of millions of rural and urban dwellers are without safe water or sanitation, millions of infants perish every year due to diarrhoeal diseases in the developing world, and a water crisis is looming over many developing and also some industrialised countries. Most of the serious diseases and lifethreatening hazards associated with drinking water are microbiological in 10

WATER SEPTEMBER/ OCTOBER 1997

nature. As indicated in C hapter 18 of 'Agenda 21' of the United Nations Conference on Environment and Development (UNCED, 1992): 'An estimated 80 per cent of all diseases and over one third of deaths in developing countries are caused by the consumption of contaminated water, and on average as much as one-tenth of each person's productive time is sacrificed to water-related diseases.' Diseases caused by microbial pathogens in drinking water are concentrated in the developing world and among the poor urban and rural households. In response to these challenging needs the supply of safe drinking water has been one of the declared goals of the World H ealth Organization since its inception. This article quantifies these needs and describes the various attempts that have been made to meet them.

The Global Situation Access to safe drinking water and adequate sanita tion is a recognised universal human need. However, in 1994 approximately 1.11 billion people in developing countries lacked access to safe water supply and 2.87 billion lacked access to adeq uate sanitation . On a global basis, i.e. including developed countries and countries in economic transition, 20 per cent of the world's population lacked safe water supply and 50 per cent had no adequate sanitation. Projections for the year 2000 show a reduction of those without safe water supply to 0. 75 billion, but an increase of those deprived of adequate sanitation to 3.31 billion (WHO, 1996a). Thus, the progress achieved on sanitation during the International Drinking-Water Supply and Sanitation Decade 1981-1990 will be largely dispelled by 2000.

The Urban Challenge The growth of the megacities will become the biggest threat to health in th~ 21st century, with an estimated 61 per cent of the world's population living

in urban areas by 2025. United Nations statistics show that between 1950 and 1995 the number of cities in the industrialised world with a population above one million more than doubled, while their number in developing countries increased sixfold from 34 to 2 13. Statistics for 1994 show that 83.6 per cent of the urban population in developing countries had access to safe water supply, whereas sanitation services were provided to only 68 .5 per cent of the urban population . This demonstrates how sanitation has lagged behind, and how piped water to the house has been a more attractive option than a sewerage line carrying away the wastes. One of the major challenges for the engineer today is the leakage of water supply pipes due to their age. There are striking examples of unaccounted-for waters reaching up to 60 per cent of the quantities which are distributed by the waterworks (Warner, 1996). A desirable, and with some effort also realistic, goal should be that all urban dwellers have access to at least a certain basic minimum amount of safe household water. Some experts consider 50 litres per capita per day as a fair enough long-term goal for the people living in suburban areas. This should allow for an acceptable quality of life and human dignity. However, in some parts of the world already 20 litres per capita per day of clean water would mean a substantial improvement whil st elsewhere 200 litres per capita per day may be deemed sufficient. The United Nations Conference on Environment and Development in Rio de Janeiro, June 1992, set as a target: 'by the year 2000, to have ensured that all urban residents have access to at least 40 litres per capita per day of safe water. . .' (UNCED, 1992). This already poses a formidable challenge to many city ~ater utilities in developing countries.

The Disease Burden The health improvements of the past decades have contributed decisively to enhance human welfare, but much


WATER more remains to be done in the developing world. One simple statistic gives a se nse of the prevailing burden of disease : abo ut 12.4 million children under age five died in 1990, with about one third directly attributable to waterborne diarrhoeal diseases. Had those children faced the mortality risks of their peers in establi shed market economies , the number of deaths would have been cut by more than 90 per cent i.e., to 1. 1 million (The World Bank, 1993). In total, it is estimated that more than five million people die from waterrelated diseases due to unsafe drinking water, unclean domestic environments, and improper excreta disposal. At any . given time perhaps half the population of developing countries is suffering from water- related diseases of w hich diarrhoeal diseases, infec tion s with internal helminths, malaria, schistosomiasis and river blindness are the mo st widespread and dangerous. H owever, the morbidity and mortality rate of water-related diseases can be reduced by 26 to 78 per cent, depending on the nature of the disease, through the provision of safe drinking-water supply and adequate sanitation (Esry et al. , 1991). The eradication of the Guinea worm , as one striking example, is fo reseen by 2000.

Water Resources in Crisis Water scarcity has become a reality in many countries in the arid and semiarid parts of the world , and variability from season to season m akes much of the water supply unavailable w hen it is most needed. This particularly affects the demands for irrigation water which account for as much as 87 per cent of the w ater consumed globally. Based on global runoff, the theoretical per capita water availability is estimated at 7,300 cubic metres per person per year (UN , 1997), which may see m like an adequate amount, but it was estimated at double this amount thirty years ago . In reality, for people in many parts of the world the actual amount available is much less. Water withdrawal at the global level was estimated at 3 ,700 cubic kilometres p er year in 1990 w hich , together with instream requirements, amounts to 54 per cent of the global runoff that is geographically and temporally accessible (Gleick, 1997). Scarcity may result from natural variation in ru noff or storage, an inability to deliver the water to where it is needed, or increasing demands that can simply not be supported in a su stainable manner from existing resources. Not only are population and demand increasing, but pollution is reducing the useability for high-quality purpo ses such as domestic water supply.

Global Water Supply

Global Sanitation

Coverage perspectives to 2000

Coverage pers pecti ves to 2000

4.5 4 3.5

4.13

3.31

3.5 2.87

3.27

2.6

2.5

2.49 2.5

1.51

1.58

1.57

1.5

1.5 0.5

0.5 0 1990

1994

2000

Groundwater supplies are coming under increasing pressure from growing human populations that consume more and more wa ter, particularly for urban drinking-water supply and agricultural irrigatio n . One res ult is that many g1oundwater reserves are being overexploited, with water being abstracted fro m them at unsu stainable ra tes . T his leads to a redu ction in groundwa ter in permanent storage and is sometimes called groundwater mining. In som e countries, fossil gro undwaters are being deliberately mined in attempts to speed the ra te of development or to reduce costs of fo od imports. H owever, the non-renewable portion , once used , is gone forever.

Drinking Water Quality Production of po table water is often turning into a challenging task du e to natural or anthropogenic problem s with its quali ty. T here ca n be natural defi cien cy of esse ntial elem ents. Perhaps the most important elementdefi cien cy problem associate d with drinking wa ter is that of endemic goitre and cretinism , both of w hich are linked to dietary iodine defi ciency. It is estimated that up to one billion people globally are at ri sk fro m iodinedefi ciency disorders with some 200 to 300 million with manifest conditions . For other elem ents, there is only a narrow range of concentrations in water w ithin w hi ch b enefi cial effects are fo und. Excess of flu o ride (above about 1.5 milligram s per litre) leads to dental tluorosis and skeletal fluoro sis at higher levels. T he Rift Valley in Africa, parts of India and parts of C hina are places w here millions of people are suffering from these health effects. On the other hand , fluorid e levels below 0. 5 milligram s per litre pose the risk of dental caries which has to be compensated for by drinking-water fluo ridation or other therapeutic treatments. Arse nic is a toxic and carcinogenic element w hich is sometimes naturally present in water. There are areas with very high concentrations with well-documented cases of chronic arsenic poisoning su ch as in southern T aiwan , C hile, M exico , C hina and W est Bengal, India. The overriding priority problem ,

1990

1994

2000

however, remains. Infectious diseases are still transmitted by contaminated d ri nking wa ter, thro ugh inade quate sanitary disposal of human excreta, lack of personal hygiene, poor food preparation and handling practices, or insufficient quantities of wa ter for do mestic purposes. T he cholera epidemic that began in Peru in 199 1 and spread to 16 o ther countries in Latin America is the m ost striking demonstration in recent history of the intrinsic interdependence of safe drinki ng wa ter, human health and economic development. In Peru , w here the o utbreak was mos t seve re, the abrupt halt of touri sm and agricultural exports cost the Peruvian economy one billion U S dollars in j ust ten weeks. T he to tal economic cost ,to Peru was m ore than three times the total national dollar investment in wa ter supply and sa nitation improvements during the decade of the 1980s (The W orld Bank, 1992) . W aterborne infec tious diseases are no t a saddening privilege of the South, as the outbreak of cryptosporidiosis in Milwa ukee vividly demonstra ted in 1993. More than 400 ,000 people were affected. The m agnitude of this outbreak , unp recedented in the recent history of indu strialised countries, and its association with a municipal water treatment plant that fulfilled existing operational and public health regulations, sent a shock wave throughout the wa ter supply sector in many countries.

Health Risk Assessment A comprehensive set of health-based criteria has been developed by WHO in the fo rm of Guidelines for DrinkingW ater Quality (WHO , 1993) . T hey are based on a broad international consensus on the assessment of the risks to human health fro m the presence of microbial agents and chemi cal sub stan ces in drinking water. An authoritative scientific basis was crea ted through more than 200 leading scientists from about 40 countries participating actively in the process. Subse quently, WHO initiated a progra m to tra nslate these guidelines into regulato ry action an d actual improvement of drinking-water safety at the local level. At the sam e time, the WATER SEPTEMBER/ OCTOBER 1997

11


WATER quantitative assessm ent of the health risk from microbiological contamination of Hea lth 8 • Optimal J ictn dv chLo:e / Risks 7 drinking water so that Range / a comparison can be 6 made with potential DMF ( ro" h re; ard , tion 5 ch emical risk from I chlorination by-products. i\ 4 \ D ntal c ries In their pioneering ThJvroi ch, noes / 3 \ work, Regli et al. 2 (1993) concluded in "n., ,e l - · · ' / 't:ri mlin ~ flu rosi "relation to disinfection by-products (DBPs) F(, 1g/I) Dental fl 1oro is that: -----------1.5 4 10'0 125 7 30 60 0.5 0 • the risk of dea th from pathogens is at need for continuous reconsideration, least 100 to 1000 times greater than the amendment and revision was recognised. risk of cancer from DBPs Consequently, a continuing process of • the risk of illness fro m pathogens is at updating (or 'rolling revision') of the least 10,000 to one million times greater WHO Guidelines for Drinking-Water than the risk of ca ncer from DBP s Quality was se t in motion, w ith a • morbidity and mortality rates from number of chemical sub stan ces and pathogen s, compared with those from mi crobiological age nts subj ect to DBPs, may be considerably higher in periodic evaluation. Addenda will be developing countries w here the sanitary issued that contain evaluations of new and health statu s is not as good or already-evaluated substances/agents • in societies w here infant mortality for w hich new scientific information rates are high and life expectancy is low, has become available (WHO, 1996) . many people would not be expected to live long enough to incur cancer, w hich Health Benefits also ca uses much higher differences in One of the maj or achievements of risk resulting from expo sure to this century is the extent to w hich pathogens versus DBPs cited above. While this last conclusion m ay seem waterborne diseases have become of minor significance in the mortality and cynical, it does reflect the true situation morbidity of most developed countries. in many developing countries today, Disinfection of drinking water ha s although this is gradually changing. played a central role in reducing the incidence of these diseases and can be Conclusions considered as one of the mo st important Safeguarding the supply of potable public health su ccess sto ries of our water for the generations to come is a times. M ost of the waterborne challenge that can only be m et if the key outbreaks that still occur in developed players-the m anagers of water countries are associated with the u se of resources, the water utilities and public untreated water or water from systems health professionals-cooperate more in which disinfec tion was inadequate. closely. The su stainable provision of Combating waterborne infectiou s drinking water can only be guaranteed diseases has been ba sed on disinfection on an interdisciplinary basis and by processes w hich mostly use chlorina- taking pertinent ecological, technical tion. This is still the most cost- effective and social constraints duly into account. safeguard for drinking-water supplies, T he demographic transitions at the particularly in developing countries. turn of the century direct priority attenAlthough the w idespread use of tion to the urban water supply arena. chlorine has significantly reduced the The rising demands, but also the risk of waterborne diseases, the chemi- unresolve d pollution issues du e to cal itself may present risks due to the inadequate sanitation, make a holistic generation of disinfection by-products, approach to the managem ent of some of w hich carry a cancer risk, albeit quantity and quality of urban water rather minor. Thus, the technological resources a must. Protec ting human h ealth from challenge emerges to minimise the carcinogenic risk from disinfectants and adverse effects related to drinking water disinfection by-products without com- thus becomes a crucial challenge which promising their effectiveness in des troy- has to be m et through preventive ing the pathogenic agents. A balance has m easures in all socio-economic sectors to be struck between the microbial and concerned. Foresight and thoughtful chemical risks without j eopardising the planning by those in command has to be safety of the potable water supply accompanied by active public participati \:m at key stages of the risk assessment (Putnam and Graham, 1993). Efforts have been made to provide a and managem ent process .

Fluorides in Drinking Water

I

I

12

WATER SEPTEMBER/ OCTOBER 1997

References Esrey SA , Potash JB , R oberts L, Shiff C (1991) Effects oflmproved Water Supply and Sanitation on Ascariasis, Diarrhoea, Dracunculiasis, H ookworm Infection , Schistosomiasis, and Trachoma, Bunetin of the World H ealth Organization, 69,5 . Gleick , PH (1997) Water 2050 : Moving Toward a Sustainable Vision for the Earth's Fresh Water, Working Paper, United Nations, New York. Putnam SW, Graham JD (1993) C hemicals Versus Microbials in Drinking Water: A Decision Science's Perspective, Journal American Water Works Association, M arc h 1993, 57-61. R egli S, Berger P , M ader B (1993) Proposed D ecision Tree for Management of Risks in Drinking Water: Consideration for H ealth and Socioeconomic Factors. In: Safety of Water Disinfection: Balancing Chemical and Microbial Risks . C raun GF ed. !LSI Press, Washington DC. The World Bank (1992) W orld Development R eport 1992: D evelopmen t and th e Environment, T he World Bank, Washington, D C , 98-11 3. The World Bank (1993) W orld Development R eport 1993: Investing in H ealth , The World Bank, W ashington, D C , 25. UNCED (1992) United N ations Conference on Environment and D evelopment. Agenda 2 1: Programme of ac tion for sustainable development. Chapter 18. Protec tion of the Quality and Supply of Freshwater R esources. United Nations, New York. United Nations (1977) R eport of the United Nations Water Conference, M ar del Plata , 14-25 M arch 1977, United Nations, N ew York, part one, chapter I, section C, paragraph 35 . United Nations (1997) Compreh ensive Freshwater Assessment, United N ations, New York. Warner DB (1995) Communi ty Water Supply and Sanitation: A WHO Perspec tive , presented at the 1996 International Plumbing Co ntrac tors Conference, Perth , Australia, 16-19 April 1996 . World H ealth Organization (1993) WHO Guidelines for Drinking-W ater Quality, Second Edition: Volume 1: R ecommendations . World H ealth Organization, Geneva. World H ealth Organization (1996a) Water Supply and Sanitation Sector M oniton·ng R eport 1996: Sector Status as of 31 December 1994, World H ealth Organization , Geneva, 41- 43. World H ealth Organization (1996b) Report of the Coordinating C ommittee M eeting for the Updating ofWHO Guidelines for Drinking-Water Quali ty, Geneva, Switzerland, 13-15 December 1995. WHO document UEH/ECEH /96 .1.

Author Dr Richard Helmer is Chief, Urban Environmental Health with the World H ealth Organiza tion's Division of Operational Support in Environmental H ealth , CH-1211 G eneva 27Switzerland.


WATER QUALITY RESEARCH

FROM CATCHMENT Professor D on Bursill is Director of th e Cooperative R esearch Centre for Quality and Trea tment W ater (CR CWQT). H e is Professor at the University of South Australia and Group M anager of the Australian Water Quality Centre, Adelaide. H e has a long involvem ent in water quality research, particularly in th e developm ent of automated analytical techniques. Dr Ton y Priestley is D ep uty Director of th e CRCWQT. H e has 23 years of exp erience of research related to the water industry with CSIRO. His interests include water trea tm en t technologies and technology transfer.

CRCWQT's Purpose The Cooperative Research Centre for W ater Quality and Treatment (CRCWQT) began operating in July 1995 with the purpose of carrying out research, education and training to assist the Australian water indu stry to supply high- quality water to its customers at an affordable price. The m any step s involve d in the delivery of high -quality, affordable water are reflected in the structure of CR CWQT research program s, w hich cover the part of the wa ter cycle that begins in the catchment, passes through collection, treatment and distribution, and ends at the consumer's tap. O verarching all these programs is the issue of human health. One of the major innovations of the CRCWQT is

Don Burslll

SUPPLYING AFFORDABLE HIGH-QUALITY WATER D Bursill, T Priestley the initiation of a specific research program targe ted at more clearly defining the relatio nship between water quality and human health. The quality of reticulated water is regarded by many developed countries as a basic indicator of the quality of life. Consequently, high-quality water is grea tly valu ed and strong cu stomer suppo rt is available to enable water companies or authorities to pursu e improvements that are considered necessary . Cost is often a secondary consideration. However, the scene in Australia is quite different. Although water should be rega rded as more valu able here

because of its relative lack of abundance, the emphasis has been on improving economic returns for the owners of water infras tru cture-governmen ts. While governments, often claim that customers are not willing to pay for any cost increases, there is often strong public dem and for water quality improvements. The tensions created in this situation emphasise the need for the work of the CRCWQT. Precious little h ealthrelated research has been done o n Australian wa ter supplies. Better inform ation on health risks and public health outcomes is essential for appropriate decision-making in the lo cal water

Tony Priestley WATER SEPTEMBER/ OCTOBER 1997

13


WATER industry. Similarly, innovative approaches to re solving accepted water quality problems can often provide more cost-effective solutions than the standard kit bag of processes and facilities. At the very least, the CRCWQT can operate as an 'honest broker' in such decision-making by water authorities and is keen to do so .

Current Research The papers from the CRCWQT in this issue of Water give a flavo ur of the research curren tly being undertaken. Our research program. has four components: • Program 1- Publi c H ealth Risk Assessment . • Program 2-Catchment and Source Water Managem ent • Program 3-Wa ter Treatment Processes • Program 4-Maintaining Water Q uali ty in Distribu tion Systems. Interlacing all these research program areas are a number of key issues that are central to wate r quality: blue- green algae and algal toxins, natural organic matter (NOM ) in water and microbial pathogens. T his matrix of research and issues form s the basis of the CRCWQT's specific research proj ects. T he result is a

QUALI TY

RESEA RCH

portfolio of . stro ngly interlinked proj ec ts. For example, the characterisation of NOM in Program 2 is relevant to proj ects on the removal of NOM in treatm ent processes and its impact on biofilm growth in Programs 3 and 4. Proj ects related to microbial pathogens are planned in all program areas . These include consideration of health risk assessm ent , identification and control of sources, rem oval in treatment processes and regrowth phenomena in dis trib ution system s. Blue-gree n algae and algal toxins are a central concern of Program 2. Concerns about their presence 111 water sou rces have also resulted in health ri sk assessment proj ec ts in Program 1 and treatm ent and removal technologies in Program 3.

undergraduate third-year water quality and treatment course and running a summer scholarship program to give final-year undergraduates some experience in the water industry. Industry workshops on specific issues are run regularly to make the industry aware of how the CRCWQT's scientific and technological knowledge can be used

'Overarching all these programs is the issue of human health.'

Knowledge Transfer The other major area of CRCWQT ac tivity relates to education , training and technology transfer. These are high-priority subj ects because one of the maj or aims of the CRCWQT is to enhance the transfer of research results to industry and the general community. The C R CWQT is running a postgraduate research program , developing an

for the public good. A workshop on the 1996 Australian Drinking Water Guidelines and their implications for system operation and public health was held in July at Ararat in Victoria. With only two years of operation under its belt, the CRCWQT is still a very yo ung organisation and its program of activity is still building up . H owever, by the end of 1997 a full ra nge of rigorously prioritised projects will be under way and the next three years up to 2000 should see a steadily growing output. While the challenges are many, the CRCWQT is confident that it w ill contribute significantly to the water industry's ability to supply high-quality water at an affordable price.

BOOKS Losing Ground: An Environmental History of the Hawkesbury-Nepean Catchment Sue Rosen. Available from Hale and Iremonger, GPO Box 2552, Sydney NSW 2001. Tel. (02) 9565 1955, fax (02) 9550 2012. Cost: $29.95, hardcover. Sue Rosen has put together a well researched and scholarly history of two hundred years of impacts on the Hawke sbury-N epean River system around Sydney. This 190- page book does not make light reading , in content or style, but it should be required reading for anyone interested in the fate of this vital river system or in rivers in general. What was particularly striking to this reviewer was the speed with w hich considerable damage was done on the banks of the Hawkesbury, within a decade of se ttlement. Clearly thi s century has no lien on the ability to damage ecosystems. Another notable aspect of th e histo1y is th e frequency and extent of flooding, which se ttlers ignored then , as they still do now. Loss of life and property was therefore commonplace, 14

WATER SEPTEMBER/ OCTOBER 1997

w hen prudence should have dictated that activities be conducted a respectful distance from the banks of thi s unpredictable wa tercourse. Rosen is harsh in her judgement of ea rl y se ttl ers and their cavalier approach to every aspect of the environment as they found it. It is easy from a late 20 th century perspective to cast aspersions on the motives and actions of people two centuries ago, but it is hard to imagine that they could be capable of stepping compreh ensively outside their prevailing paradigm s. Criticism of ac tions today is easier to accept and perhaps this book will help to enlighten som e decision-makers and planners before the river is further degraded.

Chri.s Davis

Environmental Awareness Training: A Strategy for Change Anne V. Vale. Available from Macmillan Education Australia, Locked Bag 12, South Melbourne 3205, tel. (03) 9699 8922, fax (03) 9690 6938. Cost: $195 According to its publishers, thi s publication is a practical training

programme for the whole organisation that can be easily tailored to your own specific needs .' Certainly, the book does provide an overview of w hat environmental management is about, what auditing means, how environmental managem ent systems (EMSs) can be integrated w ith quality and health and safety systems (a valuable perspective), how to initiate an EMS and several legal case reviews and environmental managem ent case studies. Don ' t expect too much detail though, because the book skates lightly over some topics. It would be useful as an introduction and an initial guide, but not as a detailed resource for a practitioner other than an awareness trainer or an EMS proj ec t leader charged with engendering enthusiasm for the approach . In that regard, it does include a disk with a training course on it, formatted for Word 2.0 or Mac. The user is invited to tailqr the manual to the organisation involved and is then guided step-by-step through the awareness training procedures . O verall, this is a useful manual if used in the right context.

Chri.s Davis


WATER

QUALITY RESEARCH

RECREATIONAL WATER GUIDELINES

FOR CYANOBACTERIA L S Pilotto, M D Burch There are no regulatory standards or guidelines in Australia for dealing with cyanobacteria in water bodies despite their prevalence in recreational water. ways and the threat they pose to public health. This has led to an unsatisfactory situation w here a range of responses are possible because individual agencies are faced with deciding w hat level of access the public can have to water bodies contaminated by algal blooms. T hese responses span a spectrum from restricting access altogether to unrestricted u se with some warnings. Evidence for adverse health effects due to exposure to cyanobacteria is based on animal studies and anecdotal reports . Few human studies have been carried out, and , to date, recommendations for safe threshold levels of recreational exposure have been based on animal toxicological studies. In a number of jurisdictions in Australia, 20,000 cells/mL is used as the threshold. However, the acceptability of this level is a matter of debate. A recent epidemiological study of recreational exposure to cyanobacteria at six sites across N ew South Wales , Victoria and South Australia sheds new light on the problem. 1 T h e study, H ealth Effects ofCyanobacterial (Bluegreen A lgae) Exposure Due to R ecreational Water-related Activities, was conducted by the authors and other researchers at the National Centre for Epidemiology and Population H ealth at the Australian N ational University. T he study investigated health effects in more than 800 people w ho were exposed to cyanobacteria w hilst waterskiing, swimming and windsurfing. T he study findings suggested that the duration of exposure and the cell density of cyanobacteria are related to illnesses such as skin rashes, eye and ear infections, mouth ulcers, diarrhoea, vomiting and respiratory symptoms. These symptoms were fo und to occur at less than 20,000 cells/mL. The study involved sub stantial collaboration and coo rdinatio n between water and health authorities in the three states. Other partners in the work included the South Australian W ater Corporation and the CRC for

Water Q uality and Treatment, South recreational wa ter exposure to Australian Health Commission , NSW cyanobacteria. Department of Health, Victorian Department of H uman Services, NSW References Department of Land and Water 1. Pilotto LS , Burch MD, Douglas RM et al. Conservation and NSW Environment Health-._ Effects of Cyanobactetial (Bluegreen Algae) Exposure Due to Protection Authority. Recreational Water-related Activities. T he paper will be published in the Aust NZ] Public Health (in press). Australian and New Zealand j ournal of Public Health later this year. It has attrac ted international interest even Authors Dr Louis Pilotto is a Fellow at the b efore its publication, because it provides the first systematic data of its National Centre for Epidemiology and type to assess the health implications of Population Health, Australian National recreational exposure to cyanobacteria. University. Michael Burch 1s a Research An expert commi ttee of the World H ealth Organisation (WHO) has agreed Biologist w ith the Australian Wa ter to use the study as the basis for the Quality Centre, Sou th Australian development of the WHO guideline for Water Corporation.

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BLUE-GREEN ALGAE AND DRINKING WATER QUALITY D A Steffensen, B C Nicholson, M D Burch, M Drlkas, P D Baker Abstract

Falconer, 1991; Fujiki et al., 1996). Nodularin has been classed as a liver carcinogen (Fujiki et al. , 1996) . There is also epidemiological evidence of a link with liver cancer in C hina (Yu , 1995). The CRCWQT studies by Professor Ian Falconer at the University of Adelaide are making a significant contribution to this very im.portant topic. The alkaloid produ ced by Cylindrosperm opsis raciborskii is associated w ith liver damage and has been shown to affect the kidney (H awkins ,et al. , 1985). T his subj ect is being addressed at the University of Adelaide in collabo ration with th e more extensive studies at the N ational R esearch Centre for Environmental ToxicIntroduction ology in Brisbane. Cyanobacterial blooms The alkaloid neurotoxins are widely recognised as (anatoxins) have been resources of tastes, odours and ported from a number of toxins in water supplies. species of filamentous cyanoControl of cyanobacterial bacteria overseas but have problems should not rely on not been detec ted 111 one approach but should Australia. N eurotoxicity in include measures in the Au stralian cyanobacteria has catchments, the source been associated solely with wa ters (rivers and reserAnabaena circinalis w hich has been shown to produce voirs), water treatment and Accumulatlon of the cyanobacterlum Anabaena c/rclnalls In a paralytic sh ellfish th e distribution systems. bend of the lower River Murray, South Australla poisons (PSPs) (Humpage et Key requirements are monitoring both the organisms and and Nodularia spumigena (nodularin). al. , 1994; N egri et al. , 1995 , 1997) (see their toxins, understanding the factors More than 50 forms of microcystin have Figure 1). Paralytic shellfish poisons, a that promote cyanobacterial growth and been described w hich differ in their complex mix ture of 18 compo unds, determining the effectiveness of water amino acid composition (Rinehart et are better know n from marine dinotrea tment processes in destroying or al. , 1994) and which may also differ in flagella tes w hi ch ca u se red tides. toxicity (Carmichael, 1992) . N odularin Aphanizomenon flos-aquae in North removing the toxins. The persistence of contains similar amino acids to those America can also produce PSPs (Ikawa toxins in the environment and their found in microcystins but only one et al. , 1985), but the toxin profiles are possible impact on crops and livestock is form has been described from N . quite different from those of Australian an issue of increasing concern but is spumigena. Both microcystins and A. circinalis (N egri et al. , 1997). poorly unders tood and will not be nodularin cause liver damage and Some evidence of live r damage considered here. inhibit the enzym es responsible for the associated with A. circinalis has been dephosphorylation of intra cellular reported by M cBarron et al. (1975), and Major Types of Toxins phosphoproteins (MacKintosh et al., Bowling and Baker (1996), but the The best known group of toxins 1990). Microcystin has been shown to presence of microcystins has no t been are the peptide s produced by promote tumour growth in experimen- confirmed. This contrasts with numerMicrocystis aerugrnosa (microcystins) tal a¡n imal studies (Falconer et al. , 1988; o us reports from elsewhere which have

Blue-green algae (cyanobacteria) have long been . recognised as a source of objectionable taste and odour in drinking water, and in recent years there has been concern about toxic m eta bolites. M anagem ent strategies should include ca tchments, n vers and reservoirs , water trea tment and distributio n systems. Monitoring the organisms and their toxins is an essential component . Thi s paper briefly reviews current knowledge and outlines a number of research programs of the Cooperative R esearch Centre for W ater Quality and Treatment (CRCWQT).

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WATER confirmed the production of microcystins by several species of Anabaena, O scillatoria and N ostoc. T he issue is fur ther compli ca ted becau se no t all blooms of a particular species may be toxic and the toxicity of a bloom may vary over time. T he importance of thi s toxin in Australia and the lack of interest elsew here has m ade thi s a high priority for the C R CWQ T, with studies on toxin detection methods and facto rs controlling toxin producti o n being condu cted at the Australian Water Q uality C entre, AWT EnSight and the U niversity of N ew South Wales. Cyanobacteria are known to co ntain lipopolysaccharides w hich m ay co ntribute to hu ma n illnes s (Co dd et al. , 1989) . However, there is very little info rmation on how widespread they are or on their significance in water supplies.

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al. , 1983). C o nfirmation of the impact of specific toxins on stock is limited , bu t includes PSPs from A. circinalis (N egri et al. , 199 5) and microcystins from M . aerugin osa (Carbi s et al. , 1995). Evidence of impac ts o n human health from dri nking water is more limited. T he most dramatic was the

with rec rea ti onal exposu re to N. spt1rmgena (Soong et al. , 1992) and A. circinalis (El Saadi et al. , 199 5). However , there is no conclu sive evidence linking the health effects with particular species or specifi c toxins. T he epidemiology studies in the CRCWQT are based at the National C entre for Epidemiology and Population H ealth , ANU with support for toxin analysis fro m AWQC in So uth Australia. These studies, along with inpu t from toxicity studies at the University of Adelaide, are making important contrib utions to the development of guidelines for toxins in drinking water both nationally and interna tionally thro ugh the World H ealth O rganisa tion Working Group. T he properties of cyanobacterial toxins are summarised in T able 1.

Figure 1 Photom icrogra ph of neurotoxic Anabaena circinalis (left) and non-toxic Anabaena s p. (right). Magnifica t ion 15OX.

Toxic Species in Australia

M uch of the earli er evidence of cyanobacterial toxicity was based o n reports of stock deaths associated with bloom s. Nodularia sp umigen a, M . aeruginosa (previously called Anacystis cyan ea) and A . circinalis have all been involved (Francis, 1878; M ain et al., 1977; M cBarron et al. , 1975;Jackson et

h ospitalisa tion of 149 perso n s w ith severe hepatoen teritis associated with exposure to C. raciborskii (H aw kins et al. , 1985) . Liver damage ha s bee n related to M . aeruginosa in the source water of a water supply (Falconer et al. , 1983). There is also some evidence of gastric and skin complaints associated

Control in Source Waters

An understa nding of the ecology of the toxic species provides opportunities for their control in rivers or reservoirs. Aspects which have been exploited are the preference of cyanobacteria fo r calm stable waters, the association with hign nutrient loading, the isolation of seeding areas and the promotion of grazing by zooplankton .

Table 1 Major classes of toxic compounds produced by cyanobacteria in Australia and their significance to drinking water quality DRINKING WATER QUALITY AND PUBLIC HEALTH SIGNIFICANCE COMPOUND

ORGANISMS

EFFECTS

DRINKING WATER QUALITY AND PUBLIC HEALTH SIGNIFICANCE

Microcystin

Microcystis aeruginosa

Hepatoenteritis Liver damage Tumour growth promotion

• Acute toxicity unlikely in large water supplies •Chronic liver damage with chronic exposure • The relationship between the tumour growth promotion properties of these toxi ns and carcinogen icity needs to be determined

Nodularin

Nodularia spumigena

As for microcystin

As for microcystin • Nodularia is not found in reservoirs-only blooms in estuarine lakes

Cylindrospermopsin

Cylindrospermopsis raciborskii

•Cytotoxic • Liver and organ damage

• Liver damage • Gast ro-i ntestinal tract damage

Neurotoxins

Saxitoxin class of compounds (Paralytic Shellfish Poisons or PSPs)

Anabaena circinalis

•Sodium channel blocking agent. Acute poisoning results in death by paralysis and respiratory failure

• Acute t oxicity only at very high cell densities • No known effects from chronic exposure • Public health sigr,ificance unclear

Endotoxins

Lipopolysaccharides (LPSs)

Most cyanobacteria . Outer cell wall component similar to LPS in cell walls of gram negative bacteria

Implicated in: • gastro-intestinal disorders • skin, eye irritation • skin rashes • respiratory allergy

• Less toxic than hepato- or neurotoxins • Effects from chronic exposure not known • Possibly significant for water supply in relation to bathing

TYPE Toxins Hepatotoxins

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WATER The CRCWQT studies in this area are centred at the University of Adelaide, the AWQ C and AWT Ensight with close links to the studies at the CRC for Fre shwater Ecology. This area of research will be a maj or fo cus for the CRCWQT in the future. Water column stability. Cyanobacteria , including all the know n toxic species in Australia, tend to proliferate in lakes, reservoirs and slow-flowing rivers , especially during summer stratifica tion. Figure 2 shows a continuously recording weather station on the lower River Murray for ecological studies of cyanobacterial grow th. Planktonic cyanobacteria are well adapted to calm waters as they have gas vacuoles that provide a degree of ¡ buoyancy control. This allows them to maintain them selves in the water column and utilise the vertical separation of light and nutrients (Ganf and Oliver, 1982) . The formation of surface scums provides the cyanobacteria with better access to atmospheric CO 2 and N 2 (Paerl and U stach , 1982). Stratification in lakes and reservoirs can be broken do w n by artificial mixing, u sing either compressed air or m ec hanical mixers. In slow flowing rivers maintaining adequate flow rates can prevent stratification. However, competition for water in many of our river sys tem s creates a numb er of economic and political difficulties for the implem entation of this approach. The tendency for cya nobac teria to co ncentrate in surface waters also provides scope for the use of booms and screens to reduce their entry into water offtakes. Nutrients. The association between cyanobac terial blooms and high nutrient loading to the water body has been widely reported (Rosenberg and Freem an, 1991). Control ca n be a broadly based approach covering improved land managem ent, pollution control and measures to limit the influen ce of the internal load from the sediments with a numb er of o ther Nutrient environmental benefit s. reduction strategies should therefore ultimately achieve reduced growth, but time may be required to achieve significant redu ction of the internal and external nutrient load. Seed sources. In temperate regions mo st cya noba cteria have distinct seasonal patterns with blooms normally in late spring or summer. In winter som e species will survive as resistant spores (akinetes), w hereas others may survive as vegetative cells (Reynolds and Walsby, 1975). Australian studies have shown that small numbers of vegetative cells of A. circinalis persisted throughout the year thus providing for grow th in the following year. In contrast the

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Figure 2 Floating weather station in Lower River Murray for eco logical studies of cyanobacterial growth

vegetative cells of A. flos- aquae completely disappeared in winter indicating that akinetes are essential for the yearto-year persisten ce of this species . Studies have identified shallow river back waters and lagoons as the areas with the highest density of both vegetative cells and akinetes. Advec tion of populations from the back waters to the river due to wind or falling water levels has been recorded. The back waters may also be a source of nutrients to the m ain reac h of the river. Isolation of these back waters especially during the cyanobacterial growth periods could therefore redu ce the incidence of blooms in the main reach of the river. Alglcldes. The most common algicides used to control cyanobacteria in reservoirs and farm dams are copper sulphate or chelated forms of copper w hich are toxic to phytoplankton at concentrations below tho se which present a h ealth ri sk to humans. However, there is increasing concern for the broad environmental impacts and the persistence of the copper in the environment. Also copper or any other algicide will lyse the cells causing the release of toxins w ith a short-term increase in dissolved toxin. Algicides therefore should not be u sed to control blooms unless the reservoir can be taken out of supply until the toxin degrades which could take several weeks. Other reservoir management options. There is increasing interest in

ways of promoting grazing by zooplankton in order to decrease phytoplankton biomass . One approach is to m anipulate fish populations so as to redu ce predation on zooplankton w hich in turn should increase grazing on phytoplankton. However, there is evidence that they are affected by the toxins produced by the cyanobacteria. Lani.pert (1981) suggested that this was

the chief function of the toxins. To this stage biomanipulation has only been used in lake m anagem ent overseas (Carpenter et al. , 1985). The application of barley straw to water bodi es has also been advocated as an algal control mea sure. Everall and Lees (1996) attributed the effect partly to promotion of grazing organism s, but mainly to the release of an unkno wn compound during decompositibn of the barley straw. While this approach may have a role in small water bodies such as farm dams, it may not be practical for large water supply storages . Other m easures which could be taken in reservoirs include pH manipulation , dosing with coagulants to precipitate nutrients and reduction of the retention times, but these approaches have not been used in Au stralia .

Water Treatment Flocculation and filtration. Toxins are secondary metabolites w hich are largely contained within the cell until the lysis or damage of th e cell. Consequently conventional coagulation and filtration can remove substantial amounts of toxin by removing the cells intact. It would be prudent to avoid any pretreatment m easures w hich disrupt the cells and lessen the prospects of removing the cells intact. In contrast to overseas studies, Velzeboer et al. (1995) fo und that alum coagulation did not damage cells. However, conventional coagulation and filtration removes little or no dissolved toxin (Him berg et al. , 1989; Keijola et al. , 1988; Falconer et al. , 1989; Jones et al., 19'93; Rositano and Nicholson, 1994). The CRCWQT is proposing some further work at the AWQC to assess the effe ctiveness of polyelectrolytes for removal of cyanobacterial cells. Oxidants. Chlorine has been shown WATER SEPTEMBER/ OCTOBER 1997

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to degrade both dissolved microcystin compounds tha_t are of particular inter- 1996). Studies evaluating the effec tiveand nodularin provided a residual of at est to the Australian water industry, ness of m embrane systems for removal least 0.5 mg/L is maintained for 30 namely algal toxins, taste and odour of cyanobac terial cells are prop osed minutes (Nicholson et al. , 1994; comp ounds and di ssolved natural within the CRCWQT program. Rositano , 1996) but it does not appear organic matter (NOM) and the simultaMicrocystin has been shown to be to be effec tive in reducing PSPs n eou s detailed study of the surface degraded by a particular strain of bacte(Nicholson et al. , 1993). Other studies properties of the adsorbents. This infor- ria from the pseudomonad gro up indica te that chlorine degrades cylin- m ation will be u sed to define the (Bourne et al. , 1996). It may be possible drospermopsin (Brisbane C ity Council, mechanisms responsible for adsorption to incorporate the bacterium or the unpublish ed data). Ozone has b een behaviour as well as the effect ofNOM enzyme responsible for the degradation shown to degrade microcys tin and on the removal of problem compounds. into the treatment process . anatoxina (Rositano et al. , 1997) and This sho uld determine reliable criteria should degrade all the toxins known to for the choice of a particular adsorbent Monitoring occur 111 Australia. The organisms. M onPotassium permanga nate itoring by microscopic has been shown to remove techniques is essential for microcystins (Rositano, early detec tion of toxic 1996) but there are no species before numbers reach reports on its effec t on dangero us levels. While the o ther toxins. Rositano number of the toxic species is (1996) reported that of most concern , the total hydroge n peroxide was number of cyanob acteria ineffective against microshould also be monitored , cystin . UV was shown to since this may be relevant to remove 50% of micro ta ste and odour problems. cys tin-LR by Rositano Also compounds such as and N icholson (1994) but lipopolysacc harides, w hi ch required very high dose may contribute to the rates. observed health effects, could Adsorption. Activated be produced by a wide range carbon is used to adsorb a of cyanobacteria. While the range of organic pollutants co nventio nal methods for and can be expected to detection of organisms develhave som e effec t on oped at 'the AWQC have di ssolved toxins . For considerable practical value, powdered activated the CRC is co nducting carbon (PAC) the critical research into more novel facto rs are contact time, gen etic methods at AWT the micro stru cture of the En sight , the University of carbon and the water N ew South Wales and quality. T he best predictor AWQC. of microcys tin rem ova l Toxicity. The most reliable potential is the m esopore m ethod for monitoring volume w hich is largely toxicity is still mouse bioasdetermined by the source say. M os t commonly this of th e ca rbon . Woodinvolves the intraperitoneal ba se d carbon has been injection of extracts of the sh own to be the mo st but the cyanob acteria, effec tive 111 remov111g extracts can also be applied microcys tins Oones et orally. Advantages of this al. , 1993 ; Donati et al. , Surface scum of Anabaena above the lock chamber at Lock 2, technique are that it can 1994). Preliminary studies River Murray, South Australia detect novel toxins w hich on cylindro spermop sin may be missed by instrumenin-dica te poor removal by a range of under specified water quality conditions tal analytical techniques and the PACs. Falconer et al. (1989) reported and produce a low-cost product that symptoms displayed may indicate the successful removal of A. circinalis will meet the needs of the water indus- type of toxin involved. The disadvann eurotoxicity, presumably PSPs , by try. This work is being undertaken at tages are that it is relatively insensitive PAC. the A WQC, the R oyal M elbourne and there is increasing concern regardFor granular activated carbon (GAC) Institute of Technology and the ing the use of animals in this type of filters the critical factors are the empty University of South Australia. test. For the toxins for w hich the mode bed contact time and the bed life of the Other treatment options. Increasing of action is known it is possible to carbon. T he latter will be influenced by attention is being focused on the use of develop biochemical tests of toxicity. the range and quantity of o ther membrane filtration techniques for The presence of microcystins can be substances in the water w hich compete removal of algae and their toxins . detected by assaying fo{ inhibition of fo r adsorptio n sites on the carbon , Microfiltration and ultrafiltration have the protein phosphatase enzym es particularly the nature and extent of been shown to be effective for removal (MacKintosh et al. , 1990; An and natural organic matter present. of cells of cultured M. aeruginosa intact Carmichael, 1994) . Other techniques T he CRCWQT is undertaking an (Panglisch et al. , 1996) while nanofiltra- include the use of isolated rat hepatoextensive proj ec t to study the adsorp- tion was shown to remove microcystin cytes (Aune and Berg, 1986), brine tion onto activa ted carb on of and nodularin (Muntisov and Trimboli, shrimp (Lahti et al. , 1995) and hamster 22

WATER SEPTEMBER/ OCTOBER 1997


WATER lung fibroblasts (Codd et al. , 1989). For PSPs it is possible to m easure the effect of toxins on the sodium channels of isolated biological material. The most widely u sed materials are cultured neuroblastoma cells (Manger et al. , 1995). The CRCWQT studies to date at AWQC and AWT have focused on evaluating currently available m ethods. Toxins. It is also necessary to determine the concentrations of the toxins, especially when evaluating the effectiveness of water treatment. Chemical analytical m ethods are ava ilable for microcystins, nodularin PSPs and cylindrospermopsin but the instrumentation is expensive and the detection limits in unconcentrated samples may not be sufficient. The mo st w id ely applied m ethod for nucrocystms and nodulann is high performance liquid chromatography (HPLC) with UV detection by photo-diode array (PDA) (Flett and Nicholson 1991; Lawton et al. , 1994). PSPs are also determined by HPLC but with po st- column deriva tisation (O shima et al., 1989) . Both types of HPLC methods are in u se w ithin the CRCWQT. The use of capillary elec trophoresis is being evaluated at AWT Ensight. Analysis of cylindrospermopsin by HPLC with PDA detection was described by Harada et al. (1994) but the liquid chromatography/m ass spec trometry (LC/MS) method described by Eaglesham (1997) may be more reliable. Enzyme-linked immunosorbent assays (ELISA) have been used for m.icrocystins (Chu et al., 1990; Nagata et al. 1996) . However, the majo r concern is the specificity of individual antibodies and the lack of cross-reactivity. Both of the available ELISA kits are being evaluated at the AWQC using Australian material.

Areas Requiring Further Study The mo st criti cal information required by water supply managers is at w hat toxin concentration do es the water become unsafe for human use . Water quality guidelines for all the toxins including the lipopolysaccharides are urgently required . It is important to identify all the toxins which are produced by cyanobacteria . R esearch on these toxins must be maintained . The recent Australian discove1y of PSPs as the toxic principle of A. circinalis in this country indica tes that much still has to be learned about cyanobacterial toxins. It is also important to maintain monitoring programs that are capable of detecting novel toxins. There will be continuing pre ss ure to develop cheap se n sitive methods for detecting toxins which can be used in the fi eld or in simply equipped laboratories. There is an ongoing n eed for

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improved understanding of the factors which promote the growth and influence the toxicity of cyanobacteria The effectiveness of existing water treatment m ethods in removing toxins is poorly known. More attention needs to be given to both pilot-scale investigations and evaluation in full-scale plants. T hese should include the behaviour of toxins with oxidants used for disinfection, the removal of cells and intracellular toxin during flocculation and toxin removal using activated carbon and membranes .

References An J and Carmichael WW (1994) U se of a Protein Phosphatase Colorimetric Inhibi tion Assay and E nzyme Linked Immunosorbent Assay for the Study of Microcystins and Nodularin. Toxicon. 32 , 1495-1507. Aune T and Berg K (1986) U se of Freshly Prepared Rat H epatocytes to Study Toxicity of Blooms of the Blue-G reen Algae Microcystis aeruginosa and Oscinatoria agardhii.j. Toxicol. Environ. H ealth. 19, 325-336. Bourne D G,Jones GJ , Blakeley RL,Jones A, Negri AP and Riddles P (1996) Enzymatic Pathway for the Bacterial Degradation of the Cyanobacterial Cyclic Peptide Toxin Microcystin- LR. Appl. Environ. Microbial. 62 , 4086-4094. Bowling LC and Baker PD (1996) Major Cyanobacterial Bloom in the BarwonDarling River, Australia, in 1991, and Underlying Limnological Conditions. M ar. Freshwater R es. 47 , 643-657. Carbis CR, Waldron DL, Mitchell GF , Anderson JW and McCauley I (1995) R ecovery of H epatic Function and Latent Mortalities in Sheep Exposed to the Blue-Green Alga Microcystis aeruginosa. Vet. Rec. 137, 12-15. Carmichael WW (1992) Cyanobacteria Secondary Metabolites - The Cyanotoxins. ]. Appl. Bacterial. 72, 445-459 . Carpenter SR, Kitchell JF and Hodgso n JR (1985). Cascading Trophic Interactions and Lake Productivity. BioScience 35 , 634-639. Chu FS , Huang X and Wei RD (1990) Enzyme-Linked Immunosorbent Assay for Microcystins in Blue-Green Algal Blooms. ]. Assoc. Off. Anal. Chem. 73 , 45 1-456. Codd GA, Brooks WP , Priestley IM, Poon GK and Bell SG (1989) Production , Detection , And Quantification of Cyanobacterial Toxins. Toxicity Asses. 4, 499-511. Donati C, Drikas M, H ayes R and Newcombe G (1994) Microcystin-LR adsorption by powdered ac tiva ted carbon. Water R es. 28 , 1735-1742. Eaglesham GK (1997) Analysis of Cylindrospermopsin from the Cyanobacterium Cylindrospermopsis ra ciborskii using HPLC/Electrospray/ Mass Spectrometry. Aust. N Z Soc. Mass Spectrom., 16th Conf Abstracts, T uP-01 El Saadi 0 , Esterman AJ, Cameron S and Roder DM (1995) Murray River Water, Raised Cyanobacterial Cell Counts, and

Gastroin testinal and D ermatological Symptons. M ed.]. Aust. 162, 122-125 . Everall NC and Lees DR (1996) T he Use of Barley-Straw to Control General and Blue-Green Algal Growth in a Derbyshire Reservoir. Water R es. 30 , 269-276. Falconer IR, Beresford AM and Runnegar MTC (1983) Evidence of Liver Damage by Toxin from a Bloom of the BlueGreen Alga, Microcystis aeruginosa. Med.]. Aust. 1, 511-514. Falconer IR, Runnegar MTC, Buckley T, Huyn VL and Bradshaw P (1989) Using Activated Carbon fu R emove Toxicity from Drinking Water Containing Cyanobacterial Blooms. ]. Am. Water Works Assoc. 81 (2), 102- 105. Falco ner IR (1991). T umour promotion and liver injury caused by oral consumption of cya nobac teria. Environ. Toxicol. Water Qual. 6, 177-184. Falconer IR, Smith JV, Jackson ARB , Jones A and Runnegar MTC (1988) . Oral toxicity ofa bloom of the cyanobacterium Microcyso."s aeruginosa administered to mice over periods upto 1 year. ]. Toxicol. Environ . H ealth. 24, 291-305. Flett DJ and Nicholson BC (199 1) Toxic Cyanobac teria 111 Water Suppli es: Analyti cal Techniqu es, Melbo urn e, Australia: Urban W ate r R esearch Association of Australia. Francis G (1878) Poiso nous Australian Lake. Nature 18 , 11-12. Fujiki H , Sueoka E and Suganuma M (1996) Carcinogenesis of, Microcystins. In : Watanabe M .F., Harada K., Carmichael WW and Fujiki H (Eds .) Toxic Microcystis, pp. 203-232. Boca R aton: CRC Press Inc. Ganf GG and Oliver RL (1982). Vertical Separation of Light and Available Nutrients as a Factor Causing R eplacement of Green Algae by BlueGreen Algae in the Plankton of a Stratified Lake. Ecology 70 , 829-844. Hawkins PR, R unnegar MTC, Jackson ARB and Falconer IR (1985) Severe Hepatotoxicity Caused by the Tropical Cyanobacterium (Blue- Gree n Alga) Cylindrosperm opsis raciborskii (Woloszynska) Seenaya and Subba Raju isolated from a Domes tic Water Supply R eservoir. Appl. Environ. Microbial. 50 , 1292-1295. Himberg K , Keijola A-M , Hiisvi rta L, Pyysalo H and Sivonen K (1989) T he Effect of Water Treatment Processes on the R emoval of H epatotoxins from Microcystis and Oscillatoria Cyanobacteria: A Laboratory Study. Water R es. 23 , 979-984. Humpage AR, Rositano J , Bretag AH, Brown R, Baker PD , Nicholso n BC and Steffensen DA (1994) Paralytic Shellfish Poisons from Australian Cyanobacterial Blooms. Aust. ]. M ar. Fresh wa ter R es. 45 , 761-771. Ikawa M , Auger K, Mosley, SP, Sasner JJ , Noguchi T , and Hashimoto K (1985) Toxin Profiles of the Blue-Green Alga Aphanizomenon flo s-aquae. In: Toxic Dinoflagenates, Anderson DM, White AW and Baden DG (Eds.) pp . 299-304 . New York:Elsevier. Jackson ARB , Mcinnes A, Falconer IR and WATER SEPTEMBER/ OCTOBER 1997

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WATER Runnegar MTC (1983). Toxicity for Sheep of th e Blue-Gree n Alga Micro cystis aernginosa. Toxicon (S uppl. 3), 191-194. Jones G, Minato! W, Craig Kand N aylor R (1993) R emoval of Low Level Cyanobacterial Peptide Toxin s from Drinking Water U sing Powdered and Gran ular Activated Ca rbon and C hlorination - R esults of Laboratory and Pilot Plant Studies. Proc 15th AWWA Fed. Convent. (Aust. ) 2, 339- 346. Keijola AM , Himberg K, Esala AL, Sivonen K and Hiisvirta L (1988) R emoval of Cya nobacterial Toxins 111 Water Treatment Processes : Laboratory and Pilot-Scale Experiments. Toxicity Assess. 3, 643-656. Lahti K, AhtiainenJ , RapalaJ , Sivonen Kand N ieme la SI (1995) Assessment of Rapid Bioassays for D etecting Cya nobacterial Toxicity. Lett Appl Microbiol 21, 109-1 14. Lampert W (198 1) Toxicity of the BlueGreen Microcystis aernginosa: Effective D efence M ec hani sm Against Grazing Pressure by Daphnia carinata. Verh. Int. Verein. Limnol. 21 , 146-1440. Lawton LA, Edwards C and Codd GA (1994) Extraction and High-Performance Liquid C hromatograp hic Method for the Determination of Microcystins in R aw and Trea ted Waters. Analyst 119, 1525-1530. MacKintosh C, Beattie KA , Klumpp S, Cohen P and Codd GA (1990) Cya nobacterial Microcystin-LR is a Potent Inhibitor of Protein Phosphatases

QUALITY

1 and 2A from both M ammals and Higher Plants. FEES Letts. 264 , 187-1 92. Main D C, Berry PH , Pee t RL and Robertson, JP (1977). Sheep Mortalities Associated with the Blue-Green Alga Nodularia spumigena . Aust. Vet. j. 53 , 578-581. Manger RL, Leja LS , Lee SY, Hungerford JM, H okama Y, D ickey RW, Granade HR, Lewis R, Yasumoto T and Wekell MM (1995) D ete ction of Sodium Channel Toxins: Direc ted cytotoxicity Assays of Purified Ciguatoxins , Brevetoxins, Saxitoxins, and Seafood Extracts.]. AOA C. Tnt. 78 , 521-527. M cBarron E J , Walker R I, Gardner I and Walker K H (1975) Toxicity to Livestock of th e Blue-Green Alga Anabaena circinalis. Aust. Vet. J. 51 , 587-588 . Muntisov M and Trimboli P (1996) R emoval of Algal Toxins U sing M embrane Technol ogy. Water (Aust.) 23(2), 21. N aga ta S, Soutome H , T sutsumi T , H asegawa A, Sekij ima M , Suga mata M , H arada K-I , Suganuma M and U eno Y (1995) Novel Monoclonal Antibodies Against Microcystin and Their Protective Activity for H epatotoxicity. Na tural Toxins 3, 78-86. Negri AP, Jones G J , Blackburn S I, Oshima Y and Onodera H (1997) Effect of C ulture and Bloom D evelopment and of Sample Storage on Paralytic Shellfish Poisons in the Cyanobac teri um Anabaena circinalis. j. Phycol. 33 , 26- 35. Negri A P , Jones, G L and Hindmarsh M (1995) Sheep Mortality Associated with

SPECIALISING IN ENVIRONMENTAL SERVICES ..,_ Environmental AudiVSite Investigations ..,_ Contamination Assessment & Remediation ..,_ Environmental Risk Assessment ..,_ Hazardous/Industrial Waste Management ..,_ Solid Waste Management ..,_ Information Management ..,_ Environmental Impact Statements ..,_ Environmental Management Planning & System Development

~RONMENTAl CONSULTING ENVIRONMENTAL ENGINEERS & SCIENTISTS Offices throughout Australia and South East Asia

24

WATER SEPTEMBER/ OCTOBER 1997

RESEARCH Paralyti c Shellfish Poisons from the Cya nobacterium Anabaena circinalis. Tax-icon 33 , 1321- 1329. Nicholson BC , R ositano J , Humpage AR and Burch , MD (1993) R emoval of Algal Toxins in W ater Trea tment Processes. Proc. 15th AWWA Fed. Convent. (Aust.) 2, 327-331 . Nicholson B C , Rositano J and Burch M D (1994) D es tructio n of Cyanobacterial Peptide Hepatotoxins by Chlorine and Chlorarn.ine. Water R es. 28 , 1297- 1303. O shima Y, Sugino K. and Yasumoto T (1989) Latest Advances in HPLC Analysis of Paralytic Shellfish Toxins. In: Natori S, H ashimoto K and Ueno Y, (Eds.) M ycotoxins and Phycotoxins '88, pp. 319-326. Amsterdam: Elsevier Science Publishers B.V. Paerl H Wand Ustach J F (1982) Blue-Green Algal Scums: An Explanation for Their O ccurrence During Freshwater Blooms. Limnol. Oceanogr. 27 , 212-217 . Panglisch S, C how C, Mole J , Drikas M , Burch M and Gimbel R (1996) M embrane Filtration for R emoval of Cyanobacterial Cells. International M embrane Science and Technology Conference, Sydney. R eynolds C S and Walsby A E (1975). Water-Blooms. Biol. R ev. 50, 437-481. Rinehart K L, Namikoshi M and C hoi B W (1994) Stru cture and Biosynthesis of Toxins from Blue-Green Algae (Cyanoba cteri a) . j. Appl. Ph ycol. 6, 159-176. Rosenberg D B and .freeman S M (1991 ) Succession Theory, Eutrophication, and W ater Quality. In: Rose, J. (Ed.) Water and the Environment. pp . 239-251 . Philadelphia: Gordon and Breach Science Publishers. Ro sitano J (1996) T he Destru ction of Cyanobacterial Peptide Toxins by O xidants U sed in Water Treatment. Research Report No. 110. Melbourne: Urban W ater R esearch Association of Australia. Rositano J and Nicholson B C (1994) W ater Trea tment Techniques for the Removal of Cyanobacterial Toxins from Water. R eport 2/94. Adelaide: Australian Centre for Water Quality R esearch. Rositano J , Nicholson B C and Pieronne P (1997) D es truction of Cyano bac terial Toxins by O zone. Ozone Sci. Eng. (in press). Soong F S, M aynard E, Kirke K and Luke C (1992) Illness Associated with BlueGreen Algae . M ed.J. Aust. 156, 67 . Velzeboer R , Drikas M , Donati C, Burch M and Steffensen D (1995) The Removal of Cyanobacterial Cells by Alu m Flocculation. Proceedings 16th AWWA Federal Convention (Aust. ) 1, 121-128. Yu , S-Z (1995) Primary Prevention of H epato cellular Carcinoma. J. Gastroenterol. H epatol. 10, 674-682.

Authors Dr Dennis Steffensen and Dr Brenton Nicholson , Michael Burch , Mary Drlkas and Peter Baker are all m embers of the Australian Water Quality Centre , Bolivar, So uth Australia and co ntributors to the CRCWQT.


WATER

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BEYOND COLIFORMS MEASURING HUMAN HEALTH M E Hellard, M I Sinclair, G Ranmuthugala, LS Pilotto, A Padiglione, B E Robertson, C K Fairley

Canberra' s water 1s drawn from The m aJor highly protec ted challenge for the catchments w ith Au stralian w ater chlorination but indu stry 1s to no filtration . The provide highmajority of Sydney qu ality drinking ca tchments h ave water at a cos ta lower level of effec tive pn ce . protection but the To do this water 1s both successfully it is chlorinate d and essential that the filtered , w hilst in benefits and risks P erth a large to human health percentage of the of bo th current ,w ater supply is and future water drawn from treatment methods groundwa ter inare know n. M eastead of surfa ce suring the effects water. of drinking water It may be on human health Nurse Kimberley Gibson collectlng a blood sample from a participant In the Water better to asses s is the major aim Quality Study the quali ty of a of all the research proj ec ts 111 Pro gram 1 of the but there is n o evidence that such w ater supply by m easuring h ealth Cooperative R esearch C entre for W ater co mpliance w ill lead to any health outcomes rather than using additional benefits. Without trying to underrate expensive water treatments to ensure Quality and Trea tment (CR CWQT). The fo cus on m easuring human the importance of the guidelines , our that all water mee ts exactly the same health is important becau se of the inter- program advoca tes defining the health levels. This is particularly so for rural national trend towards achieving lower benefits before implem enting changes wa ter supplies. Figure 1 is a diagramlevels of microorganism s and chemicals to a water supply rather than m aking matic depiction of such a multifaceted in drinking water. Before follo wing this changes to 'comply' with a level that was approach to water quality. trend, however, Australians are asking not m eant to be a standard in the first Current and Future Studies an important question: 'Is there a health place. Performing complica ted or highly benefit to be gained by reaching these To Filter or Not to Filter? The W ater new levels?' Au stralia is able to ask this specific laboratory tests m ay not be the Quality Study being conducted by the because it has adopted guidelines rather solution to measuring the risk to human C R CWQT is an excellent example of health from a particular water supply. using health outcomes together with than standards. The Australian Natio nal H ealth and The detec tio n of Cryptosporidium plate counts to measure drinking water M edical R esearch (NHMRC) drinking oocys ts in a water supply provides an quality. This three million dollar study water guidelines provide an excellent excellent example of thi s. T es ts for uses the most powerful epidemiological resource, but their role is often misun- Cryptosporidia are unreliable, difficult tool, a randomised , placebo-controlled derstood . Unlike the mandatory to perform, expensive and often all of study, to determine if there is any standards used in the United States, the these !1 •2 •3 •4 There is the additional gastroenteritis attributable to an unfilAustralian guidelines simply reflec t problem that the acceptable level of tered water supply with some coliform what is regarded as good water quality C1yptosp oridia in a water supply is also regrow th in its distribution system. The regardless of its source . Nonetheless, a uncertain because we don't know the study will measure the dif£ rence, if any, number of people in the water industry infective dose of these organism s.5 , 6,7 in the levels of gastroenteritis in people Setting a single 'level' for coliforms, drinking w ater that has had potential and government view the guidelines as standards and attempt to 'comply' with for example, may not be appropriate pathogens rem ove d compared w ith lower coliform counts or lower disin- w hen considering the vast difference in those drinking ordinary tap water. The fec tion by-product levels. This has the the qu ality of source waters throughout pathogens being rem oved are protozoa, potential to significantly increase costs Au stralia. M os t of M elbourne's and bacteria and viruses . If there is no differ-

Introduction

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ence betwee n the tw o gro up s, this control system in indu stry. The current sary reliance on ani mal rather th an would suggest that disinfection strate- surveillance systems that operate in m ost human studies. H uman studies in this gies to redu ce coliform counts to m ee t countries thro ughout the world have area are di ffi cult because of the lo ng the guidelines is not required. In considerable delays associated w ith latency peri od between exposure to addition , it would suggest that filtration them and m ay not be sensitive enough DPB s and the development of ca ncer. of M elbourne's highly protected wa ter to detec t outbrea ks of waterborne An innova tive approa ch, again using a supply is no t justified for the prevention gastroenteriti s. The standard surveil- randomi sed control trial, has bee n of gastroenteriti s. If the study shows that lance systems may also be unable to developed by CR CWQT resea rchers in gas troenteriti s attributable to drinking identify the ca u se of an outbrea k , Canberra w ho are currently studying the po tential association between DBPs water is occurring, analysis of the clini - without further specific studies . cal specimens from participants m ay The need fo r a rapid and almost 'real and bladder ca ncer. Mi cronucl ei in help in indi cating w here the po tential time' surveillance system that can link bladder cells shed into the urine are contaminatio n is occ urring in the m easures of gas troenteriti s to wa ter being used as a biological marke r of system. If protozoa are ca using nigher quali ty data is the reason behind one of damage to the nu cleus of the cell and levels of gastroe nteritis, filtration of th e the proj ects in Program 1. T rus study, may indi ca te the carcinogenic potenti al wa ter supply m ay be appropriate, jointly funded by M elbourne W ater and ofDBP s. w hereas if bacteria are the cau se, the the CRCWQT, is investigating the use di stributi o n sys tem and levels of of different fo rms of electronic data, Risk Assessment chlorine residuals may need to be such as the incidence of di spensing Mathemati cal mod els using ri sk examined . antidiarrhoeal m edi ca tion or casualty assessment methodology can also be a Whilst the Water Qu ality Study will attend ences for gas tro enteritis , as useful tool for assessing the risks and provide useful information on specific markers of an o utbreak in the commu- benefits of vario us wa ter treatments. pathogens (e.g., Cryptosporidium), this nity. The abse nce of epid emics of C MP S&F, a Program 1 member, is is no t its primary focus. To supplement gastroenteriti s w hen a sensitive surveil- criti cally assessing this area of resea rch in the W ater Qu ality Study, the lance system is in place would provide conj uncti o n with the health professio nC R CWQT is planning a series of case useful informatio n fo r planning future als and wa ter industry partners. A maj or co ntrol studi es . Thi s is a differe nt expenditure on plant and equipment. outcome of this work will be identifying Cancer? Th e potential ri sk of the role of ri sk assessment in the wa ter epidemi ological design well suited to specifi c pathogens. A series of these di sease, particularly cancer, associated industry . The work will also provide the studies is planned for most Au stralian with disinfection by-products (DBPs) basis for a series of research proj ec ts to capital citi es. The studies will be useful has created considerable concern world- refine the accuracy of this approac h. in assessing the relative contribution (if wid e. Unce rtainty in thi s area is Toxins. Cya nobacterial toxins and any) of wa ter as a risk fac tor for refl ected by the substantial variation in their contributi on to malignancy is o ne cryptospo ridio sis and in se tting an recommended levels of DPB s. Thi s area th at is poorly understood, with acceptable level fo r Cryptosp oridium un certain ty is in part du e to the neces- little contributi on as ye t from research oocys ts m drinking on humans. A rece nt wa ter. If these studies populatio n study carshow no association ried ou t by the Human Health Studies between cases of cryptoC R CWQT did not Water Quality Study sporidiosis and drinking demo nstrate any geoPathogen Case Control tap water during a period graphi cal association Studies of time w hen Cryptosbetween the frequency Disinfection By-product Study poridi um oocysts were of cyanobacterial bloom detec ted in drinking occ urrence and gastrowa ter, it would be intestinal cancer m ortreasonable to infer that ality . Thi s study and Toxicological current levels of oocysts similar studi es have Studies shown it is difficult to in drinking water were obtain solid toxicologinot associated with cal data on research in significant disease. Alterhumans. An indication natively, if the study of the potential of these shows an association toxi ns to cause disease between cases of cryptoWATER can , however, be obsporidiosis and drinking QUALITY tained from animal water, this would indistudies. The CRC for cate that water treatment W ater Quality and is required to reduce the Trea tment has funded number of oocysts. such work at Adelaide Best Real-time monitoring? Management University using an In addition to the Practice animal-based m odel. specific studies m entioned above it is imporThe Future tant to have a system in I place that can continuThe fo cus of the Microbial Pathogens ou sly monitor the level C R CWQT's work on Plate Count of gastroenteritis in the human health brings Total Coliforms communi ty . Such a new challenges. P erFaecal Coliforms system is referred to as a haps the most impor'surveillance system ' and tant of these is effecFigure 1 Assessing' water quality-a multifaceted approach is akin to a quality tively communica ting

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WATER the results of these studies with our cu stomers and seeking their advice. Potentially problematic in the short term, this trend of involving the public in decision-making is inevitable and it is one of the recommendations in the 1996 NHMRC drinking water guidelines. The Water Quality Study must take account of effective communication. If it shows there is no gastroenteriti s attributable to drinking water, this may be best communicated to the public by saying, 'Th e results of this study indicate that the risk of gastroenteritis from drinking water, if there is a risk at all, is so small that we have not been able to measure it. More specifically it .suggests an individual could expect their drinking water to cause less than one attack of gastroenteritis every ten years or so, and in fact the number of attacks may be zero.' Alternatively, if the study shows that some gastroenteritis is occurring from drinking water, it would provide the necessary evidence that further water treatment is indicated. In communicating this to the public it would be necessary to discuss the effect of additional water treatment on an individual's water bill in dollars p er year.

The

challenge o{ providing highquality drinking water at a cost-effective

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price throughout Australia into the 21st century is paramount. The CRCWQT believes this will best be achieved by an integrated approach , monitoring water quality and measuring human disease attributable to water, rather than simply monitoring microorganisms in the water. This approach will ensure that investment in the water indu stry is driven by evidence of a health benefit and not the desire to comply with guideline values . Through its various research projects the CRCWQT is playing an important role in meeting this goal, w ith proj ects in Program 1 addressing fundamental questions about the effects of water on human health.

References 1. Vesey G, Hutton P , C hampion A, Ashbolt N, William K, Warton A, et al. Application of Flow Cytometric Methods for the Routine Detection of Cryptosporidium and Giardia in Water. Cytometre 1994; 16: 1-6. 2. Vesey G, Slade ] S, Byrne M, Shepherd K, Fricker C R. A New Method for the Concentration of C1yptosporidium Oocysts from Water. journal of Applied Bacten'ology 1993; 75: 82-6. 3. Rose] B, Landeen L K, Riley KR, Gerba C P. Evaluation of Immunofl orescence Techniqu es

for

Detec tion

of

Ciyptosporidium Oocysts and Giardia Cysts from E nvironmental Samples.

4.

5.

6.

7.

Applied and Environmental Microbiology 1989; 55 (12): 3189-96. Smith H , Rose J. Wa terborn e Cryptosporidiosis . Parasitology Today. 1990; 6(1):8-12 . Rose J B, Haas C N , Regli S. Risk Assessment and Control of Waterborne Giardiasis. Am J Public H ealth 1991; 81:709-13. Addiss D G, Arrowood MJ, Bartlett ME , Colley D G, Juranek D D, Kaplan J E, et al. Assessing the Public Health Threat Associated with Waterborne Cryptosporidiosis: Report of a Workshop. MMWR 1995;44(No RR-6):1-20. DuPont H L, C happell CL, Sterling CR, Okhuysen PC, Rose ] B,Jakubowski W. T he Infectivity of Cryptosporidium Parvum in Healthy Volunteers. N Eng ] M ed 1995; 332 (13): 855-59

Authors All authors are members of Program 1 in the CRCWQT. Drs M E Hellard, M I Sinclair, A Padlgllone, B E Robertson and C K Fairley are at

the D epartment of Epidemiology and Preventive Medicine, Monash University, Commercial Road, Prahran. Drs G Ranmuthugala and L S Pllotto are at the National Centre for Epiderruology ~nd Popubtion H e~ lth .

Austral{an Canberra.

Nat{onal

Un{vers{ty,


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Abstract Natural organic matter (NOM) has been identified as causing problems in the supply of safe, clean water. This paper o utlines th e approac h being adopted by the C ooperative R esearch Ce ntre fo r Water Qu ality and Treatment (CRCWQT) in addressing these problem s in all stages of water supply from catchment thro ugh treatment to distribution.

Introduction The presence of NOM in water has been acknowledged for many years. It has long been known to be responsible for the colour of water but it was not until the late 1970s that NOM was identified as reacting with chlorine to form a range of di sinfec tion byproducts known as trihalom ethanes , the m ajor component being chloroform . Since then the reaction of NOM with not only disinfectants but also other chemicals used in water treatment and the influence it exerts on virtually every aspect of water treatment has begun to be appreciated. The CRCWQT has identified the key role that NOM plays in water Table 1 Relationship between Dissolved Organic Carbon (mg/L)

11.4 9.3 8.5 5.3 4.4

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quality and treatment and is approaching the NOM problem at all stages in the complete wa ter cycle-from catchment through treatment to the distributio n system .

Impacts on Treatment Curse No. 1: Increased coagulant and disinfectant dosage. N atural

organic matter is one of the key fac tors in determining both coagulant and disinfectant dose . Previou s studies (Bursill et al , 198 5; Morran et al, 1996) have shown that the removal of NOM from a particular raw water will result in a decrease in the amount of coagulant required to treat that water to achieve aes thetically acceptable quality. The amount of disinfectant required is also reduced. Curse No. 2: Disinfection byproducts. N atural organic matter reacts

with di sinfec tants to produ ce byproducts. The interaction of natural organics with disinfectants no t only results in higher doses being required but also results in the formation of bypro ducts, a number of whi ch have adverse health effects. Data in Table 1 obtained with water from the Lexton R eservoir 111 Victoria effecDOC and Formation of Trihalomethanes tively illustrates Simulated Distribution System the impac t of Trihalomethane Potential increa sing con{Âľg/L) centrations of 243 NOM o n the 154 extent of by143 product forma77 tion as described 55 by the concen-

tra tion of trihalomethanes formed under specific experimental conditions (Morran et al, 1997) . Chlorine is still the maj or disinfectant used in Australia, and indeed the world, and reaction with chlorine has been shown to produ ce trihalomethanes and a range of byproducts which have been included in the 1996 National Health and M edical R esea rch C o uncil guidelines . Most Au stralian authorities have no t determined the co ncentration of these compounds in their water but based on overseas data it is quite feasible that these by-products will be the limiting factor in the use of chlorine. H owever, the solution is not simply to apply an alternative disinfec tant, as NOM is not specific with what it reacts to but will be oxidised effectively by a range of other disinfectants such as ozone and even ultraviolet light. The extent of byprodu ct formation with these other disinfectants is slowly becoming clearer. Curse No. 3: Regrowth. Natural organic matter is a food source for bacterial grow th in distribution system s. This has bec ome very apparent in European distribution system s in recent years where ozone is used as the primary disinfec tant , gen erally followed by secondary disinfection with chlorine. O zo nation w ill oxidi se NOM to sm aller more biodegradable organics that are easily assimilated by bacteria and this has caused considerable increase in biofilm growth in distribution systems w hich utilise ozone for disinfection. However, although ozonation exacerbates this problem , all w aters whi ch contain assimilable WATER SEPTEMBER/ OCTOBER 1997

29


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component controlling the cost of treatment and the final water quality.

NOM is of particular importance, as this appears to be one of the controlling factors in bacterial regrowth occurring in the distribution system. As the world trend towards ozonation as an alternative to chlorination and the general lowering of disinfectant doses and residuals is increasing, an approach adopted in Europe and spreading rapidly to the USA has gained widespread recognition. This foc uses on limiting the amount of assimilable organic carbon (AOC) present in thtt water by various biological treatments so that the need for any residual disinfectant in the distribution system to control bacterial regrowth can be limited or eliminated . Althou gh there is little or no biological treatment as such practised in Australia to date, it is clear that this approach has some merit and that there is a need to reduce both the assimilable and total amount of NOM present in Australian waters if authorities are to meet limits on both disinfectant dose and disinfection by-products (DBP).

The Nature of the Matter

The CRCWQT Approach

N atural organic m atter is a complex matrix of organic chemicals w hich can be derived from soil, living organisms and/or plant detritus and partial bacterial degradation from any or all of these sources. There have been nu111.erous attempts to define NOM. However, it has been concluded that NOM cannot be simply defined as particular chemical struc tures but only broadly characterised into generic groupings. These definitions are complicate d by the seasonal and temporal variability to which the NOM is subj ected. The character of the NOM is dependent on the source from which it is derived and the chemical and biological degradation to which it has been subj ected. The character of the organics is of significance. Recent work has shown that the NOM of Australian waters differs considerably from that in Europe (Pieronne, 1993; Withers et al, 1996). This may impact on the behaviour of van o us trea tn1.ent processes. The importance of natural organics has been acknowledged recently by the United States in their proposed Disinfectant and Disinfection By-product Rule where enhanced coagulation has been designated as the best available technology for total organic carbon removals with removal determined as a percentage dependent on influent TOC and alkalinity. TOC less than 2 mg/L prior to disinfection requires no trea tment, while TOC levels above this require removal of between 20 to 50%, with higher removal specified at higher TOC and.lower alkalinity. The assimilable component of the

Having identified the significant role that NOM plays in water quality and water treatment , the CRCWQT is approaching the NOM problem at all stages in the complete water cyclefrom catchment through treatment to the distribution system (see Figure 1) .

Figure 1 The CRCWQT approach

organic carbon (AOC) will promote bacterial growth. The proportion of assimilable organic carbon in Australian waters has only been explored very briefly (Withers et al. , 1996) but showed that most Australian surface raw and treated waters studied contained significant AOC and would promote bacterial growth. Curse No. 4: Membrane fouling.

Natural organic matter adsorbs irreversibly on membranes , fouling them and limiting both their effectiveness and lifetime and hence their use in the wa ter industry. This is a particular problem with membranes with smaller effective pore sizes such as ultrafiltration and nanofiltration membranes. However, even microfiltration membranes which have been more widely used in Australia suffer from NOM problems. The problem with these systems is that they do not remove colour (caused by NOM) and generally coagulation is used as a pretreatment system prior to the membrane; this also cau ses decrease in membrane flux and lifetime. Curse No. 5: Interaction with activated carbon. Natural organic

matter is adsorbed strongly by granular activated carbon, at least for a short period of time. This reduces the ability of the activated carbon to remove pollutants, makes the activated carbon less efficien t and reduces the effective lifetime of carbon beds. Even w hen powdered activated carbon is used, the NOM competes with the pollutant for adsorption sites on the carbon and the removal efficiency of the pollutant can be significantly reduced. It is clear that the presence of natural organic matter affects a number of aspects of wa ter quality and treatment technology and may well be the key 30

WATER SEPTEMBER/ OCTOBER 1997

Catchment and Source Water Management The character of the NOM is critical to its performance in various water treatment processes and b etter techniques need to be developed to allow this to be defined in the most effective and relevant manner. A proj ect in Program 2 will investigate methods to improve the characterisation of the organic matter associated with NOM. It will also foc us on determining the influence of the origin and degradation pathways (both chemical and biological) of the sample on these characteristics. Strategies will also be developed to minimise the transport of organics by amelioration of the soil. This will be undertaken in collaboration wi th the Cooperative Research Centre for Soil and Land Management. The techniques developed will be used to assist in projects in Program 3 on Water Treatment Technology which evaluate the impact ofNOM on water treatment.

Water Treatment Technology A major proj ec t in Program 3 1s aimed at maximising available treatment systems for removal of natural organics and developing novel processes to reduce organics. There is a range of processes that can be u sed for the


WATER removal of NOM and to develop a suitable technique it is necessary to have a better understanding of these processes and their application. Initially this proj ect will seek a better understanding of the removal of natural organics by the range of currently available treatment processes, focusing on coagulation , enhanced oxidation (using ultraviolet irradiation ) and 10n exchange resins at the three research nodes: the Australian Water Quality Centre, the Royal Melbourne Institute of T echnology and CSIRO Molecular Science. Som.e assessmen t of m etal oxides and clays, membranes and oxidation/granular activated carbon will also be undertaken . T his should lead to the identifica tion of particul ar components of the NOM that contribute to AO C or are reactive to disinfection, forming DBPs. It should also identify particular processes or steps in these processes which are more suited to the removal of the problematic components of NOM. This will then allow modifica tion of current trea tmen t processes to maximise efficiency of treatment and removal of NOM and 111.ay lead to development of novel pro cesses to better and more economically reduce NOM.

QUALITY

RESEARCH

The most appropriate solution may well be a combination of processes. Some of these pro cesses, such as powdered activated carbo n and membranes, are already used in combination in current operating water trea tment plants. It is anticipated that series application of these combined processes will result in a se rial effect on the organics. H owever, some combinations may result in a synergistic effect due to a change in the character of the organics. For example, ozonation of the NOM to smaller, more biodegradable organics enhances the performance of a granular activated ca rbon filter by promoting biological degradation of the NOM in the GAC filter. This combination of ozone and GAC is generally referred to as biologically activa ted carbon (BAC) . As a result of this project, the most promising combination of processes for re moving NOM will be identified for furth er research. T hi s proj ect will undertake a detailed evalu ation of the coagulation of a limited range of raw waters that contain well characterised natural organics to understand the mechanism and kinetics of coagulation by undertaking detailed j ar testing under specific conditions and

using additional analyti cal tools such as electrophoretic mobility w here appropriate. This will evaluate the impact that different components of the NOM have on the coagulation process and determine the characteristics of th e organics removed by coagulation , by characterising raw and treated waters . This will initially foc us on the use of aluminium sulphate under a variety of operating conditions , including coagulant dose, pH and alkalinity. Some preliminary work is illu strated ·n Figure 2 using apparent molecular weight distribution to charac terise the NOM in samples from Myponga R eservoir before and after treatment with alum. Whilst absorbance has bee n normalised for easier comparison, the actual absorbance after treatment would be smaller because the concentration of NOM is lower. The figure indica tes a very clear shift in the apparent molecular weight distribution after trea tment to the smaller molecular weight compounds. The same types of low molecular weight co mpound s are present, as indica ted by the peaks, after treatment, in the same position as the shoulders on the raw water distribution. However, virtually all the compounds present in the raw wa ter above molecu-

10000 0.16

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2000

4000

3000

5000

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Figure 2 Apparent molecular weight distribution before and after treatment

1 )

Figure 3 The effects of different types of NOM on the adsorption of MIS

> 30000 UF fraction

0.08

0.06

chlorinaled lractlons

,--

< 500 - - - • 500-3000 · · · · · · · 3000-1 0000 ·-·· ·- 10000-30000 .......... >3 0000

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Figure 4 Apparent molecular weight distribution before and after chlorination

1000

2000

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4000

5000

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7000

Apparent molecular weight

Figure 5 Apparent molecular weight distribution of various NOM fractions after chlorination

WATER SEPTEMBER/ OCTOBER 1997

31


WATER lar weight of 1200 have been removed by the treatment process. This is clear evidence that the coagulation/flocculation process removes the high molecular weight compounds. The smaller compounds are more difficult to remove by traditional water treatment processes. A proj ec t aimed at developing optimum adsorption processes is evaluating the impact of NOM on the removal of algal metabolites such as MIB and toxins and seeking to understand the varying components of the NOM that are critical to a better performance of activa ted carbon for its removal of pollutants. This is effectively illustrated in Figure 3 for the adsorption . of the ta ste and odour m etabolite methyl isoborneol (MIB ) from M yponga R eservoir water u sing powdered activated carbon (Newcombe et al. , 1997). The curves indicate the mass of MIB adsorbed at equilibrium as a function of the equilibrium solution concentration. In NOM-free water the adsorption of MIB is high. However, in natural water the adsorption of the compound is much lower due to the presence of NOM. The character of the NOM also influences the competitive effect on MIB adsorption. As the figure shows, the adsorption of MIB in NOM of the low molec ular weight ultrafiltration fra ction is lower than adsorption in the high er molecular weight frac tion, indicating that the smaller NOM compounds, those closer in size to the MIB molecule, compete for adsorption sites more effectively. A proj ect on alternative disinfection regimes is evaluating the effect ofNOM fractionation on the formation of DBP and AOC w h en using ozon e and ozone/chlorine. T he impact of chlorination on the character of the NOM was assessed using apparent molecular weight distribution to characterise the NOM. Figure 4 shows the apparent molec ular weight distribution of a NOM fraction which has been isolated u sing an anion exchange resin and frac tionated using ultrafiltration. The unbroken line shows the distribution of the >30000 fraction . T he molecular weight is mu ch lower than the 30000 Daltons designated by the ultrafiltration membrane manufacturer. Globular proteins are used to calibrate such membranes and it has been shown that these compounds are inappropriate as a model for NOM (Aiken, 1984; N ewcombe et al. , 1997) . After a sample of the fraction was chlorinated using 20 mg/L chlorine solution over a period of eight days, the apparent molec ular weight distribution changed dramatically (see Figure 4) . The interpretation of the distribution of the chlorinated 32

WATER SEPTEMBER/OCTOBER 1997

QUALITY

RESEARCH

sample is difficult, as the chlorination process did not remove any NOM, the character has changed to become less UV-absorbing. However, some important conclusions can be drawn from the results. Virtually all the NOM in the molecular weight range > 4000 has been either broken down to smaller molecular weight species, or changed very dramatically to render all the compounds in that size range non-UV absorbing. This fraction had a DOC concentration of 8 mg/L, and after chlorination the total trihalomethane concentration was 80 :g/L. In relative terms the trihalomethane concentration represents a very small percentage of the total DOC present in th e sample. However, the change in the NOM o erall has been significant. In terms of mass of DO C the other disinfection byprodu cts are more important. Ultrafiltration frac tions of nominal molecular weight < 500, 500-3000, 3000-10000 and 10000-30000 were also subj ected to the same chlorination procedure. Figure 5 indicates that the products formed on chlorination of all fractions are very similar in character, whereas the original N OM fra ctions h ad distinctly different molecular weight distributions. A proj ect assessing the role of polyelectrolytes in water treatment will also interact with these proj ects. The initial aim of this project is to develop tagge d polym ers, focusing first on polyDADMAC w hich is used as a primary coagulant to enable the extent of residual polym er to be determined. Later in the proj ect the formation of possible by-products from the interactions of residual polyelectrolytes and a ra nge of disinfectants will be assessed. However, it is apparent from early work in this project that the NOM present is interacting with the tagged polymers and causing difficulties in the fluorescent techniques being employed . The use of alternative fluorescent tags may overcome this problem. However, the interaction is of interes t and m ay provide a useful tool for m easuring particular components ofNOM. A proj ect focusing on the role of coagulation and adsorp tion processes in combination with microfiltration m embrane processes is going to be undertaken. It is hoped that by studying such process combinations, the removal of natural organic compounds on conventional microfiltration membranes can be achieved with minimal fouling of the membrane surface. The potential advantage of this combination of processes is the development of a low operating cost membrane system that is capable of removing both soluble and particulate pollutants from drinking

water. M embranes offer an excellent opportunity for achieving reliable, low chemical usage and low maintenance technology w hich is cost- effective and ideally suited to small communities. The research aims to establish ways of first converting the soluble materials into a particulate form by a variety of methods including coagulation with a metal salt or cationic polymer or adsorbing them on clay, metal oxide, powdered activated carbon or finely divided ion-exchan~ resin. It is intended as much as po ssible to use the same raw waters and techniques to characterise the NOM both for the raw and treated wa ters in all the Program 3 proj ects discussed above to m aximise the u se of resources and minimise the duplication of work . T his necessitates considerable communication and cooperation to ensure that project officers are working on the same waters and communi cating relevant information to other CRCWQT staff. This w ill be facilitated by regular meetings and seminars to discuss results by participants working in all NOMrelated proj ects.

Distribution Systems The presence of biofilms in distribution systems has a detrimental impact on wa ter qualiry ¡ both physically, because of decreased system efficiency and aes thetic problem s due to the sloughing from the surface, and microbiologically, due to their possible contribution to the recovery and growth of microorganisms either directly or by providing protection from the effi ciency of disinfection. NOM and particularly the assimilable component of NOM has been identified as a critical nutrient for the growth of bacteria in distribution sys tems and the growth ofbiofilms. A project in Program 4 will investigate the factors influ encing the development of biofilms under controlled conditions and NOM will be one of the fac tors evaluated. By determining both the levels and the fraction of NOM w hi ch may promote biofilm growth it is anticipated that management strategies for the control of biofilm growth in distribution sys tems may be fo und. Biofilms have been formed on test surfaces in annular reactors at Australian W ater Technologies in preparation for this work . Initial investigations have been to establish appropriate methods which can be u sed to m easure NOM utilisation by biofilm grown on distribution waters.

Publlc Health Risk Assessment The impact of NOM on health has not been overlooked. In Program 1


WATER there is a proj ect to assess the risk associated with the formation of disinfec tion by-products. T his proj ect aims to determine if exposure to disinfection by-produ cts in chlorinated drinking wa ter will alter the frequ en cy of micronucleated bladder epthileal cells in humans thereby providing evidence fo r, or against, the carcinogenic po tential ofDBP. Micronuclei are DNA fragm ents or w hole chromosomes that are not incorporated into daughter cells d uring mitosis. C hromosomal aberrations are thought to be an initial step in carcinogenesis. This study is a double-blinded, randomised controlled cross- over trial w here one group receives chlorinated bottled water w hile the second gro up receives unchlorinated bottled water. Study participants will be interviewed to identify and quantify water co n sumption . The frequency of micronucleated bladder epthileal cells will be examined and differences in the two groups determined using t-tests and analysis of variance. T he frequency of micronuclea ted cells will also be examined at vario us DBP levels to determine if a dose response relationship exists. T he analysis will adj ust fo r po tential confounders. One hundred and for ty subj ects will be recruited to detect a relative risk

QUALITY

RESEARCH

of 1. 4 w ith 80% power and 95% confidence.

Conclusion This C R CWQT offers a uniqu e opportunity to develop solutions fo r the maj or water quality issue ofNOM from the source water thro ugh the treatment process and the distribu tion system to providing a better water quality at the custom er tap w hile still maintaining an affordable price. The C R CWQT will also put the need for new or improved technology in perspec tive with the public health risk associated with the different levels of treatment.

D isinfec ti on Bypro duct Fo rmatio n , Proceedings of the AWWA 17th Federal Convention, M elbourne, M arch, 1997 . N ewco mbe G , Drikas M and H ayes R (1997) T he Influence of C haracterised N atural Organic M aterial on Activated Carbon Adsorption: II Effect on Pore Volume D istribution and Adsorption of MIB , Water R esearch, 31 (5), 1065-1073 . Pieronne P , R eport on French- Australian Programme, Ind ustrial R esea rch Australian W ater Quality Centre R eport, July 1993. Withers N , Drikas M and H ambsch B, (1996) Compariso n of Bacterial Regrowth Potenti al in German and Australian Wa ters, W ater, 23, 4, 59- 62 .

Acknowledgements

References Aiken G R (1984) Evaluation of Ultrafiltra tion for D etermining M olecular Weight of Fulvic Acid, Environ . Sci. Technol. , 18, 978-981. Bursill DB , Hine P T and M orranJ Y, The Effect of N atural Organics on Wa ter T reatment Processes, Proceedings of the Australian W ater and W as tewater Association 11th Federal C onve ntion , M elbourne, April , 1985. Morran J Y, Bursill D B , D rikas M and Nguyen H , A New Technique fo r the R em oval of N atural Organic M atter, Proceedings of the AWWA W aterTECH Confere nce, Sydney, M ay 1996. M orran J Y, Bursill D B , D rikas M and N guyen H , A Simple M ethod to Reduce

T he author gratefu lly acknowledges the use of extracts from proj ect proposals prepared by a number of C R C participants and data generated by staff at the AWQ C, in particular Gayle N ewcombe.

Author Mary Drlkas is the Program Coordinator fo r W ater Treatm ent T echnology 111 the Coop erative R esearch C entre for W ater Q uality and Trea tment. She is Principal R esearch Chemist at the W ater Treatment U nit located at the Australian W ater Q uality C entre.

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WATER there is a proj ect to assess the risk associated with the formation of disinfection by-products. This project aims to determine if exposure to disinfection by-products in chlorinated drinking water will alter the frequency of micronucleated bladder epthileal cells in humans thereby providing evidence for, or against, the carcinogenic potential ofDBP. Micronuclei are DNA fragments or whole chromosomes that are not incorporated into daughter cells during mitosis. Chromosomal aberrations are thought to be an initial step in carcinogenesis . This study is a double-blinded, randomised controlled cross- over trial where one group receives chlorinated bottled water w hile the second group receives unchlorinated bottled water. Study participants will be interviewed to identify and quantify water con sumption. The frequency of micronucleated bladder epthileal cells will be examined and differences in the two groups determined using t-tests and analysis of variance. The frequency of micronucleated cells will also be examined at variou s DBP levels to determine if a dose response relationship exists. T he analysis will adjust for potential confounders. One hundred and forty subj ects will be recruited to detect a relative risk

QUALITY

RESEARCH

of 1.4 w ith 80% power and 95% confidence.

Conclusion This CRCWQT offers a unique opportunity to develop solutions for the m ajor water quality issue ofNOM from the source water through the treatment process and the distribution system to providing a better water quality at the customer tap w hile still maintaining an affordable price . The CRCWQT will also put the need for new or improved technology in perspective with the public health risk associated with the different levels of treatment.

Disinfection Byproduct Formation , Proceedings of the AWWA 17th Federal Convention, Melbourne, March, 1997. Newcombe G, Drikas Mand H ayes R (1997) The Influence of Characterised Natural Organic Material on Activated Carbon Adsorption: II Effect on Pore Volume Distribution and Adsorption of MIB , Water R eseaTch , 31 (5) , 1065-1073 . Pieronne P, Report on French-Australian Research Programme , Industrial Australian Water Quality Centre Report, July 1993. Withers N, Drikas M and Hambsch B , (1996) Comparison ¡ of Bacterial Regrowth Potential in German and Australian Waters, Water, 23 , 4, 59-62.

Acknowledgements

References Aiken G R (1984) Evaluatio n of Ultrafiltration for Determining Molecular Weight of Fulvic Acid, Environ. Sci. Technol. , 18 , 978-981 . Bursill D B, Hine P T and Morran J Y, The Effect of Natural Organics on Water T reatment Processes, Proceedings of the Australian Water and Wastewater Association 11th Federal Convention, Melbourne, April, 1985. Morran J Y, Bursill D B , Drikas M and Nguyen H , A New Technique for the Removal of Natural Organic Matter, Proceedings of the AWWA WaterTECH Conference, Sydney, May 1996. Morran J Y, Bursill D B, Drikas M and Nguyen H , A Simple Method to Reduce

The author gratefully acknowledges the use of extracts from proj ec t proposals prepared by a number of CRC participants and data generated by staff at the AWQC, in particular Gayle Newcombe.

Author Mary Drlkas is the Program Coordinator for Water Treatment Technology in the Cooperative R esearch Centre for Water Quality and Treatment. She is Principal Research C hemist at the Water Treatment Unit located at the Australian Watet Quality Centre.

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WATER

QUALITY

RESEARCH

PREDICTING AND MAINTAINING

DRINKING WATER QUALITY IN DISTRIBUTION SYSTEMS G Kastl, I Fisher Abstract W ater distribution system s ac t as large reactors with considerable residence time (days). These residence times are sufficient for disinfectant inactivation and production of undesirable levels of bacteria. R eactions in the distribution system proceed in bulk and on pipe biofilm surfaces. The research program of the Cooperative R esearch Centre for Water Quality and Trea tment (CRCWQT) includ es a chlorine decay model in bulk water, based on reactions between chlorine and organic carbo n in wa ter. The hypothesis is that the surface reaction ca n be co rrelated with the bulk reactio n . C hlorine decay in service reservoirs and the outlet main is used as an example to demonstrate this m ethod. The model can be a very useful tool to model chlorine behaviour in sec tions of a di stribution sys tem , including mixed reservoirs. The model is also suitable to use in the design of rechlorination system s.

Introduction Drinking water distribution systems extend from the first point of disinfection to consumers' taps. They consist of

Exhumed water main showing accumulatlon of blo-corroslon products and encrusted blofllm

interest in imp roving this quality, through both m anagement of existing system s and design of modified or new system s. There are two broad types of issues related to tap water quality-health risks and aesthetics . The C RCWQT is giving priority to issues of health risk and addressing these directly through epidemiological studies and risk assessment in R esearch Program 1. In contras t, R esearch Program 4 is specifically conc erned w ith determining and predicting water quality characteristics in the distribution system s that influence the concentra tion or load of pathogens arriving at the tap , initially throu gh process studies of pipe 'elem ents.' A number of proj ec ts h ave commenced in Program 4 to:

'Chlorine decay due to a biofilm surface can be modelled as a bulk reaction with an equivalent pipe diameter.' complex networks of pipes, pumps and reservoirs, designed to meet operational flow requirem ents such as minimum pressure and maximum variations in daily demand. Historically, little attention has bee n paid to the adverse impacts w hich design decisions may have on tap water quality, yet tap water quality is now a possible basis fo r revocatio n of water authorities' operating licences. There is now increased

• determine fac tors influencing biofilm development • study retentio n and release of pathogens in biofi.lms • define interactions of disinfectants (initially chlorine) with both the bulk water and pipe biofilms . found betwee n R elatio n ships environmental conditions (such as nutrients, shear at the pipe wall and chlorine conce ntration) and biofilm development or pathogen retention will be built into an integrated quality model, so that predictions can be m ade of the quality changes expected along a single pipe (represented as a string of pipe elem ents). These predictions will be tested against measurements from real pipes not connected to consumers' taps, so that environme'ntal conditio ns can still be controlled. After the model is validated adequately for single pipes, a similar (possibly simplified) model will be embedded in an existing pipe network m odel, such as EPANET, WATSYS or WATER SEPTEMBER/ OCTOBER 1997

35


WATER Nel growth

QUALITY

·1

.

E :, 0 >

. ) .5

;fl.

I

Net growth

RESEARCH

WATER SEPTEMBER/ OCTOBER 1997

3

4

d I Im et er (m

Figure 2 Fraction of bacteria in bulk volume as a function of pipe diameter

Processes Influencing Water Quality Drinking wa ter contains a number of substances in mg/L concentrations such as mineral salts, chlorine and organic matter. Som e of these substances are reactive eno ugh to undergo tra nsfo rmation during transport to a consumer. Biofilm on pipe surfaces can transform substances at a much fas ter ra te than bulk reactions. Douglas (1997) identifi ed biofilms and fa ctors w hich contribute to 'stable water' as deserving high priority in Australia. The photograph on the front page of this article shows to what extent pipe surface can be affected by biologically enhanced corrosion. Probably the m ost reactive compound commonly present in drinking water is chlorine. The reaction of chlorine with natural organic matter (NOM) in wa ter and biofilm is usually responsible for chlorine decay during transport through the distribution sys tem. These processes are shown schematically in Figure 1. D ecline in chlorine concentration carries potential health risks due to bacterial regrow th. On the other hand , excessive chlorine conce ntrations present problem s of

Current perception of blofllm structure (reprinted with permission from the Annual Review of Microbiology, Volume 49, copyright 1995 by Annual Reviews Inc.)

36

2 p Ip e

Figure 1 Bulk and surface processes in drinking water distribution systems

This paper focu ses on the developm ent of process models affecting disinfec tant concentration in a sys tem comprised of a single pipe and a service reservoir. The paper demonstrates the insight w hich can be obtained concerning optimisation regimes, even before the detailed results from biofilm developm ent experiments are available.

5 0 5 0 5 0 5 0 5 0 0

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PICCOLO. M odel predictions ca n be compared against measurements made in real distribution system s. A similar quali ty model for services will also be n eeded then to provide a complete represe ntation of quality changes in such sys tem s. This combination of model developm ent alongside experimental proj ects is intended to provide a powerful tool for testing system management strategies in w hich managers can have confidence becau se it is validated against experim ental data at each stage of developm ent . The m ajor strategies to be considered are: • m anipulation of flow regimes • pipe and service reservoir cleaning m ethods and frequency • optimal disinfec tion regimes.

4 4 3 3 2 2 1 1

ta ste, odour and disinfection byproducts. The window of chlorine dose operation is narrow and sometimes cannot be sati sfi ed with a single chlorine dose. In bulk water, chlorine reacts with organic matter fo rming chloride and disinfection by-products. Bacteria can replicate using biodegradable dissolved organic carbo n (BDOC) as a food source . Floating bacteria can attach to the surface and become part of biofilm. On the pipe surface , bacteria can reach high concentrations. Higher growth rates on the surfa ce are probably du e to biofilm enzymatic hydrolysis of organic compounds to produce lower molecular m ass m olecules, w hi ch are rea dily u tilisa ble by bacteria. The total bacteria in a water pipe are composed of bacteria on pipe smface and bacteria in bulk water. Figure 2 shows the relationship betwee n percentage of bacteria in bulk w ater and the pipe diam eter based on the assumption of a constant volume concentration of bacteria of 10 5 /ml and a surface concentration of 10 7/cm 2 (Dukan et al., 1996). The reaction of chloramine is more complex and will be addressed later. However, a similar approach can be applied. With increasing pipe diameter a higher proportion of bacteria is in bulk water, becau se of the smaller surface to volume ratio . Even in pipes of3 m diameter, more bacteria are contained in the biofilm than in bulk water. Surface biofilm contains attached bacteria and ex tracellular polymeric substance (EPS) produced by attached bacteria. The biofilm consumes BDOC from the bulk to sustain and propagate bac teria and to produce EPS. D epending on hydrodynamic conditions and other factors, the bacteria can migrate from biofilm to bulk water and vice versa. The smaller the pipe diameter, the greater the effe ct of biofilm compared with bulk reaction. Conversely, in large service reservoirs, the reaction rate approaches the bulk reaction rate. Biofilm activity destroys chlorine, allowing greater survival of bacteria on


WATER

QUALITY

RESEARCH 1 .20

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the surface and further in the pipe. It can also release bacteria to bulk water. · The bacteria in some types of biofilm may release compounds w hich influen ce tas te and odour and these compounds may again be m etabolised by a differe nt component of the biofilm. In this light, biofilm can be a source of, or ' trea tment' fo r, taste and odour. Biofilm can also be active in oxidation of Fe2+ and Mn 2+ forming insoluble hydra ted oxides, w hich are the cause of dirty water complaints. Biofilm on the surface is not a continuou s layer, but is composed of cell clusters attached to the surface . An impression of biofilm structure is illustra ted on the previous page (Costerton et al. , 199 5).

Chlorine Decay Modelling T his section considers only chlorine decay becau se of available data. A similar approach is envisaged fo r modelling the decay of chlo ramine, w hich is frequently used to provide a longer-las ting residual di sinfec tant action . The di sappearance of chlorine in drinking water distribution system s is a complex process, w hich includes a number of parallel and sequential reactions with compounds in the bulk wa ter and on surfaces . In the first approximation , the effect of reaction can be described as first order with respect to chlorine (Equation 1).

dt

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0

Figure 3 Comparison of first order total chlorine decay and rea ction with organic compounds model (Armida le treated water, temperature 20° C, 1 and 2 mg/ L initial dose)

dcCl

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0.00

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w here: k is the reaction constant [h· 1] cCI is concentration of chlorine [mg/L] tis the reaction time [h] This is only an approximation which ass umes that chlorine w ould react indefinitely at a rate determined only by chlorine concentration. As it is well known that initial decay (approximately the first four hours) is considerably

Figure 4 Reservoir outlet chlorine concentration as a f unction of chlorine dose in rese rvoir (Armida le treated water, temperatu re 20° C, residence time 5.8 days)

fas ter, the first order decay equation cannot produce accurate results soon after initial chlorination or rechlorination. Such a model can only be applied to a distribution system in a series of disconnected pieces. Kastl (1994) and Fisher and Kastl (1996) modelled free and combined chlorine decay in bulk water as a set of reactions between organic compounds and chlorine. Thi s model describes realistically the decay of free and combined chlorine, including the effects of initial dose and temperature and is used in all examples presented in this paper. The model is particularly suitable to m odel rechlorination as it accommodates decreasing decay rates w ith each repea ted chlo ri ne dose. Figure 3 shows the variation in a pseudo-k param eter calculated fro m reactio n rate and Equ atio n 1. In contrast, in a true fi rst order reaction , k is a constant. It is apparent from Figure 3 that kp,eudo is fa r from constant during the reac tion and dependent on initial chlorine do se . The initial value of kp,eu,lo is about 0 .1 5/h and it approaches a stable value of approximately 0.01/h, w hich is a decay constant fo r combined chlorine. The time for k to reach a stable value is a function of chlorine dose. This is because the slowest rate is the decay of combined chlorine. A stable k value is achieved only w hen free chlorine has been consumed , so the higher the initial dose, the longer it takes to reach a stable state. If a new dose of chlorine is intro duced , the decay constant increases as free chlorine is again available to react with organics. Chlorine is no t only consumed in the bulk water, but also by the biofilm surface. The biofilm itself is nourished by BDOC in bulk water. In a typical drinking water distribution pipe, water moves regularly and biofilm status is determined predo minantly by the quality of water in contact with biofilm (w hich 111 turn influ en ces water quality) . It is suggested that there m ay be one group of organic compounds w hich

reacts with chlorine in bulk water and also feeds the biofilm , or alternatively that there are two groups, one reacting with chlorine, the other feeding the biofilm , but they are usually present in relatively constant ratio. T hi s no tion is suppo rted by experim ental results of chlorine decay in dis tribu tio n system s. Although the overall reaction ra te of chlorine decay varies con siderably between system s, the ratio between the total and bulk reaction rate remains relatively constant for pipes of certain diameter and equilibra ted biofilm . Equation 2 describes total decay in a pipe as contribution of bulk and surface reaction . Rt =R*1 +R V S d Equation 2

where: R 1 - to tal reaction rate [g/m 3/h] !\, - bulk reaction rate [g/m 3/h] R ~ - smface reaction rate [ m2/h] - pipe diameter [m] The surface reaction constant R , is not known and is difficult to measure di rec tly. W e can introdu ce a new variable equivalent pipe diameter dequi according to Equation 3. d

.

R S = R V *=.!!I!!!. 4

Equation 3

Combining Equations 2 and 3, the total reactio n rate can be related to bulk reaction rate with equivalent diam eter dequi' the only unknow n param eter appearing in Equation 4: R

....1 = (l +

R.

d

·

eqm)

d

Equation 4

It has been observed in field studies (Clark, 1994) that the ratio of R/~ is relatively con stant in di stribution systems, with typical values between 2 and 4. The larger the equivalent diameWATER SEPTEMBER/ OCTOBER 1997

37


WATER 1.8 ~ - - - - --

------, 1.2 ~ - - -- - -- - - -~

1.6

is

l c

8

RESEARCH

QUALITY

1.4

• • • • • • free chlorine

1.2

- t o t al chlorine ---combined chlorine

0 .8

0.6 0.4

... __

i

08 - • .. • .. ·free chlorine

- - t o t a l chlorine --combined chlorine

0.6

C

!!C 8

0 .4

0 0

0 + ---f---C.- " - " j ~ - + - - - - - t - ----i

0

C 0

0.2

\

0.2

i

5000

5000

10000

15000

20000

25000

pipe length [m]

10000 15000 20000 25000

pipe length [m]

Figure 5 Ch lorine profile along outlet pipe (d=500 mm, temperature 20° C, dequ;=500 mm, f low 30L/s, dose 1.6 mg CI/L)

ter, the more active the biofilm. In a pipe of equivalent diameter, chlorine is inactivated by biofilm at the same rate as bulk water. Chlorine decay due to a biofilm surface can be modelled as a bulk reaction with an equivalent pipe diameter. Equivalent pipe diameter dequi has to be correlated with system parameters, but it is believed that variation of dequi is much lower than variation in decay rates. If this hypothesis proves correct for a wide range of water distribution systems, it will be possible to model chlorine decay principally on the basis oflaboratory data for bulk reaction with reduced field measurements. This would make modelling cheaper and a more attractive tool to predict water qualiry in distribution systems .

Figure 6 Profile of chlorine along main outlet pipe (d=500 mm, temperature 20° C, dequ;=500 mm, flow 30L/s, dose in reservoir 2 mg/Land pipe boost 0.5 mg CI/L)

around 10 km. The curve of total chlorine is quite steep, so water at the start of the pipe has a relatively high level of chlorine and at the end has no free chlorine at all. Rechlorination doses can be divided between reservoir, to 'stabilise' water, and the outlet main pipe to boost to the required level. Dual rechlorination do sing into reservoir (2mg/L) and boosting pipe (0.5mg/L) is shown in Figure 6. From a comparison of Figures 5 and 6 it can be concluded that dual dosing, into reservoir and pipe, results in a flatter chlorine profile and a presence of free chlorine at the end of the pipe. This is beneficial to the consumers who are not exposed to high chlorine doses but are still protected from microbial contamination.

Chlorine Decay In Service Reservoir Outlet Main

Conclusion

A model of chlorine decay in bulk water can be applied to parts of a distribution system . For example, large reservoirs have small surface to volume ratios so chlorine decay approaches the bulk reaction rate . If the reservoir is mixed, concentration is equal to the outlet concentration. AQUASIM software (Reichert 1994) was used to apply the chlorine interaction model to sections of a drinking water distribution system. Figure 4 shows the effect of chlorine dose on outlet concentration of a mixed reservoir. Figure 4 shows that neither the total nor free output chlorine concentrations are a linear function of dose, as would be predicted by the first order chlorine decay. Chlorine can also be dosed directly into the outlet main. A profile of free and combined chlorine along a 500 mm main pipe with flow of 30L/s and chlorine dose of 1. 6 mg/L is shown in Figure 5. Figure 5 shows that even combined chlorine is present at the end of the pipe (20km), free chlorine disappears at

The conclu sions reach ed can be summarised as follows: • surface processes, namely biofilms, influence water quality in drinking water distribution systems • in modelling water qualiry in drinking water distribution systems, bulk and surface/biofilm effects have to be included • biofilm reactions have to be better understood to predict qualiry changes in the distribution system • the first order reaction for chlorine decay is not a sufficiently accurate model and a better model such as one including reaction with organics has to be used to successfully model/design rechlorination • it is hypothesised that bulk and surface reactions are linked • application of the above principles enables one to model free and combined chlorine decay in reservoirs and pipes • for rechlorination of a reservoir, the optimum conditions can be achieved by do ~ing chlorine into the reservoir to stabilise water and into the pipe to boost

38

WATER SEPTEMBER/ OCTOBER 1997

the chlorine level for transportation • the developed model is a very useful management tool to explore options to control chlorine decay in distribution systems, even though it is based primarily on laboratory measurements of bulk water.

References Clark RM (1994) Modelling water quality changes and contaminant propagation in drinking water distribution system: a US perspective, J Water SRT-Aqua 43 , 3133-143. Costerton JW, Lewan,dowski Z, Caldwell DE, Korber DR and lappin-Scott HM (1995) Microbial Biofilms, Annual Reviews of Microbiology 49 , 711-745. Douglas RM (1997) Setting public health priorities in drinking water quality and treatment,JA WWA 24, 1, 16-17 . Dukan S, Levi Y, Piriou P, Guyon F and Villon P (1996) Dynamic modelling of bacterial growth in drinking water networks, Wat.Res. 30 , 9, J 901-2002 . Fisher IH and Kastl G (1996) N umerical modelling of water quality in distribution systems , Proceedings WaterTECH Sydney 27, 28 May 1996, AWWA. Kastl G (1994) Strategy for chlorine level optimisation in Armidale water supply, AWT EnSight report No. 94/170. Reichert P (1994) AQUASIM-A toll for simulation and data analysis of aquatic systems. Wat. Sci. Tech. 30 , 2, 21-30.

Authors Both authors work in Australian Water Technology's Environment and Science Division. George Kastl is a chemical engineer with a background in modelling of chemical reactor systems. H e has designed rechlorination stations, including a booster station with electrolytic generation. Dr Ian Fisher is the c,oordinator of Research Program 4 in the CRCWQT. He is a Principal Consultant with AWT. He was formerly Sydney Water's Principal Scientist for Drinking Water and Supply, in which role h e was involved in modelling and measurement of qualiry factors.


WASTEWATER

Jurg Keller In Manlla pursuing a current research project aimed at Improving wastewater management In developlng countries

With the introduction of nutrient standards into efflu ent di scharge licences in Au stralia, the number of BNR plants, both greenfield and retrofit, is burgeoning. Figure 1 shows the number of operating BNR plants in Australia and Queensland, based on the authors' inquiries. By the end of this year there will be 27 plants operating in Au stralia, of w hich 13 will be in Queensland. Many more are in the design or construction phase. Some of the newer plants have to meet eilluent quality requirements that are among the most demanding worldwide. The good news is that they are actually able to achieve these very high standards. R eal life operating performance results of such plants will form an important part of the upcoming BNR3 Conference being held by AWWA's Queensland Branch and the IAWQ in Brisbane at the end of November. The first generation of BNR plants (beginning with Penrith in 1984) was designed to meet efflu ent quality objectives' as distinct from legal statistical limits as are common now. For example, some of the new Queensland plants are being designed to meet 50 percentile N and P concentrations of 5

mg/1 and 1 m g/L respectively, with these nice looking simulations and absolute limits set at twice these values. graphs. More attention is therefore being given Efiluent variability is now an importo operability and real life performance. tant consideration. Studies of full-scale With the introduction of the national plants have given the rough rule of competition policy, proj ect delivery thumb that geometric standard deviam ethods are shifting and cost competi- tion for the usual parameters is about 2, tiveness is of equal importance. but with quite a wide ra nge. Operating Dynamic modelling has become flexibility seems important to enable practical with the advent of commercial operators to reduce variability and to software products such as BioWin or meet longer term changes in wastewater Nimbus w hich have been developed at charac teri stics. These co n siderations The University of Queensland. How- have given rise currently to two differever, the current process models are not ent approaches. In the fully compartperfec t. The microbiological funda- m entali sed , co ntinu o us flo w sys tem mentals are not well understood, and (e .g. modified UCT design), the processes such as simultaneous nitrifica- designers are aiming to engineer a large tion/ denitrifica tion and prefermentation are only NO. OF OPERATING BNR PLANTS starting to be incorporated. Vl - - 0 - AUSTRALIA H owever, the current 1z 25 ········lk .. ··· · QUl.:.bNSI..ANO models have proven to :'0..S represent the performance <.:> 20 z of full- scale plants well ~ 15 eno ugh for practical "'0.w Q 10 purposes provided the key u. 0 parameters are prop erly ci calibrated. This last issue is z O+ - - - - ----..,.c....-~-~-~--< essential, ye t often 92 82 86 88 90 94 96 neglected in the euphoria YEAR of ·being able to ge t all WATER SEPTEMBER/ OCTOBER 1997

39


WASTEWATER degree of inherent flexibility in the design. Alternatively, the less compartmentalised oxidation ditch and intermittently operated designs (e .g. sequencing batch reactors) offer greater operating flexibility th ro ugh the modification of operating conditions with time. In the interests of maximum operating flexibility some plants also incorporate molasses dosing facilities. These are intended to enable low N standards to continue to be met if the wastewater TKN:COD ratio becomes adverse. Prefermentation to assist in the biological P as well as N removal is being incorporated in abou t half of all new BNR plants. T he economics of this process com pared with increased chemical use (for P removal) depend on the degree of enhancement required. The capital cost of prefermentation becomes more attractive as plant size increases, though it will generally be favoured if P removal enhancement of more than 2-3 mg/Lis needed. There is currently no generally accepted model of the prefermentation process, and empirical methods are being used for design. However, development of such a model is progressing well at the Advanced Wastewater Management Centre with some results being presented at the BNR 3 Conference. Five different types of fermenters are in use in Australia: sidestream complete mix, complete mix/ thickener, intermittent complete mix, static thickener and on-line activated primary tank. Cost pressures have led to designs with lower sludge ages. Greater attention has also been paid to the marginal cost trade-offs associated with increasing levels of biological nutrient removal versus chemical enhancement. Plants are more likely now to incorporate supplementary chemical dosing facilities. Capital cost of new BNR plants is reducing. R egression of the contract costs of 14 Australian plants gives the following rough estimate: Cost ($ million) = 0.86 (1000 EP capacity) o. 75 (r = 0.77). T he cheaper plants run about 25 per cent below this. Expansions or retrofits are not included in this estimate, as their costs vary dramatically with the level of modification needed . Presently, there is an increasing trend to optimise the existing facilities even beyond their original design requirements before expanding or even rebuilding the entire treatment train. This obviously has potential for maj or cost savings. What is in store for the future? There are significant advances likely in three key areas: â&#x20AC;˘ operation optimisation â&#x20AC;˘ improved fundamental knowledge â&#x20AC;˘ innovative treatment processes. 40

WATER SEPTEM BER/OCTOBER 1997

Plant optimi ation through dynamic modelling and on line control is already starting to be implemented in Australia and applications overseas are increasing rapidly. Particularly in Europe, energy savings of over 30%, better and more consistent efiluent quality and overall lower operating costs have driven the process ahead for a number of years. More recently, the retrofit of BNR processes into existing carbon removal plants through process optimisation has gained significant momentum. Since this aims at capital cost reductions, savings in the order of millions of dollars are possible. It is very encouraging to see that these developments have also started in Australia and are spearheaded by local councils, research rganisations and companies . T he recent initiative by the Queensland Department for Local Government and Planning to encourage innovative treatment technologies has created major interest and will certainly foster such new developments . To support the ongoing plant optimisation, better fundamental knowledge is essential. Processes such as simultaneous nitrification/denitrification are already generally accepted (and are being implemented in models), but their background is still not well understood. However, with novel microbiological and engineering techniques, the knowledge base is constantly expanding. Similarly, fundamentals of biological P removal are being discovered rapidly and this information could well be of major importance in achieving an even better treatment performance. Recently, interest in nitrification has also been renewed since new knowledge in the 'established' biological processes have been gained and systems have evolved that operate at very low dissolved oxygen concentrations. Australian scientists and engineers, including researchers at the AWMC , are at the leading edge worldwide on these developments. This can provide a competitive technological advantage to the local industry. N umerous visits by BNR experts in recent times and the upcoming BNR3 Conference will further reinforce the important role Australia plays in BNR technology progress worldwide . There are also exciting new developments on the horizon . Fundamentally novel concepts such as the ANAMOX process (biological reaction of ammonium with nitrite to form nitrogen gas) will likely take some years before th eir real potential can be assessed. Other technologies, however, will have an impact much sooner. Such an example is the attached growth process using suspended carriers which

has the potential to eliminate one of the major bottlenecks in traditional activated sludge plants, the clarifiers. This is of significance not only in new plants (particularly to handle high flow situations) but even more so in retrofit and upgrade situations where there are usually no alternatives to improve solids separation without additional clarifiers . BNR technology has certainly come a long way in Australia over the last decade. Presently, the standard of plant design and performance is among the best worldwide. However, advances in the operation are still needed and these developments are under way both in Au stralia and overseas. These are supported locally by strong research and development activities w hich have to find their way into full-scale plants to generate ultimate benefits to the industry and the community at large. The BNR3 Conference in Brisbane (30 N ovember-4 December 1997), jointly organised by AWW A and IAWQ , offers an ideal opportunity to assess progress achieved to date and foster links for the future.

Authors Dr Jurg Kell er and Ken Hartley are both at the Advanced Wastewater M anagement Centre, a joint initiative between the Coo'p erative Research Centre for W aste Management and Pollution Control and The University of Quee nsland. They can be contacted at Department of Chemical Engineering , The University of Q ueensland , St Lucia 4072 tel. (07) 3365 4730 or http ://www.cheque.uq. edu.au/awm

New AWWA Members ACT Lou ise Rose

New South Wales Peter Ad cock, APS, Christopher Burton , Gary Carlyle, Su za nne Clark, Ant hony Courtman , Kurt Dahl, Raymond Pelletier, Ia n Phillips, Shaune Speed, Siobnan Spoljari c, Salvatore Valen zisi , Ri chard McManus

Victoria Ash ley Lang, Wang Industries

Queensland Damon Gree nwood , John Taylor

South Australia Mark Lynch , Andrew Telfer

Western Australia Balakuma r Balasunderam , Gavin Broom , Graeme Harris , Kevin Lampard , John Perry , Richard Wa lker, Gary Watson , Grundfos Pumps, Hamersley Iron

Overseas W Leung


ENVIRONMENT

Burwood Beach soil bed odour control faclllty

Odours from waste treatment facilities are not everyone's idea of a pleasant topic for discussion. In fact, they are a significant problem for anyone living close to such a facility. Odour control and the monitoring of odours was the subj ect of the inaugural Odour Interest Group meeting on 22 May 1997.

Odour Measuring Those present were told of existing legislative trend s and attempts to integrate these with odour modelling to achieve a sa tisfactory solution. Regulatory authorities typically invoke a standard of one odour unit (OU) at the boundary of facilities. By definition, this is effectively the threshhold of sm ell. However, Terry Schulz of C H2M HILL stated that in reality the level of recognition of a smell was closer to 3 to 5 OUs. H e described a case study for a sewage treatment works in Western Australia where a clear odour complaint/odour level correlation was found. Complaints were found to occur at OUs of about 7 to 8 and this enabled a relaxed guideline, for which the operating authority of the treatment facility was most grateful. The measurement of smell or 'olfactometry' is now almost an exact science with available techniques providing accurate, reproducible analysis.

John Jian from the Centre for Wastewater Treatment at the University of New South Wales talked about how olfactometry is done. A sample of foul air is collected using a pump and bag arrangement. The sample is sent to a laboratory to undergo analysis ofOUs. For open area odour sources an odour hood is used to collect the foul air. The level of odours is actually m easured by a panel of people (carefully screened-sm ell varies betv.reen people depending on age, whether they smoke and other factors). The samples of air are diluted and 'wafted' via an olfactometer to the panel, who are located in separate booth s. The panel must indicate w hether they can detect an odour. Straight air is also fed to the machine via a separate port to force the panel to make a choice between the odorous and straight air. There are now several laboratories which can undertake this type of analysis incvluding AWT , UNSW and CH2M HILL.

Odour Control Odour control can be by way of source control or end-of-pipe solutions. There is no general rule for controlling odours, but very much a 'horses for courses' approach when adopting a strategy.

In sewers, for example, there are unique opportunities for control. J enny Williams of CMPS&F Environmental said the problem s of odour and corrosion occur with the onset of septicity. Temperature is particularly important, as it will govern the rate of microbial processes in the sewer. Strategies range from chemical do sing (for example, using chlorine or peroxide to kill the microorganism s) , giving the bugs w hat they want-o:>..rygenation or dosing with nitrates to provide oxygen for the microbes, to removing the smell (for example, by ventilating the sewers and treating the off-gases). Treatment of off-gases and open foul air sources also has a range of solutions. These involve covering of th e source of odours, extraction/ventilation (both of which are common to all odour control systems) and ven tilating through a control system. Control options include activated carbon adsorption , chemical scrubbing and biological scrubbing. Activated carbon is extremely effective and has a high odour removal capability (>99%) but is typically used for lower organic co ncentrations. David H ealy of James Cumming and Sons said carbon may be manufactured from a variety of materials (including bitumenous coal and coconut shells) and the preferred material is dependent WATER SEPTEMBER/ OCTOBER 1997

41


ENVIRONMENT on the characteristics of the foul air stream to be treated (the pore and structure of the carbon varies significantly between materials). Chemical scrubbing is typically used for high air flow rates. Mike O'Brien of AWT described the impressive chemical scrubbing application at M alabar STP, where there are six packed towers each of 45 m 3/second capacity (5 on line)-possibly the largest facility of its kind in the world. Each tower involves caustic and sodium hypochlorite dosing in the single unit. The capital investment was very high at the original time of installation ($10 million in 1989) and after odour complaints were still occurring, Sydney W ater spent a lot of time and effort in developing a modified approach to en sure achievemen t of odour removal reached the necessary 99.9 % (which modelling showed was required to m ee t co mmunity expectations). Biological scrubbing involves u sing micro-organisms to break down the pollutants in the foul air stream . One increasingly common option is the soil bed odour control system w here the soil supports a microbial population w hich readily adapts to each situation to degrade a multitude of odorous gases and voltaile organic compounds. At this point the author jumped to

his feet to say that fo r the more slowly degradable compounds (hydrocarbons, phenols) more detention time is required. Soil bed system s have several significant advantages: • they involve a natural process, and consequ ently have the least adverse environmental impac t of any odour control method • there are minimal operating costs with the only operational requirements being for ventilation power, irrigation requirements , and grass cutting • they have a very high performance capability for removal of odours and gaseou s compounds, and they have been proven in numerous situations. Soil beds do take up considerable land area, but there are some innovative solutions to overcome thi s, such as locating the facility on the roof of a building. Soils beds have been used in Australia and overseas in many applications for treatment of odorou s air emissions. CMPS&F Environmental has designed many soil bed facilities (both sewage and industrial wastewater treatment plants), including the largest such facility in Australia at Burwood Beach Wastewater Treatment Works (Newcastle, serving 180,000 EP). The facility has been operating for three years now. It has consistently removed odours by over 99%.

Tap Do n't just look- feel the uncluttered elegance of the m odern tap ; run your fingers up that tall penile one; w rap your palm aro und a squ at one; touch gloves with the tough fi st of the cube tap; or if 'now' taps tire yo u get a remake of an old brassie with a four spoked handle and screw-in hexagon top ; w hichever, when the bath room 's done and yo u stand in the doorway marvelling also at the tiling your lover might squeeze yo ur hand and point out a tiny pregnant sack of water res ting at the tap spo ut and rem ark how fa r it's come; through the new copper pipes up the side of yo ur old home; the stree t m ains; the filtration plant; through dark concrete tubes; the open channel; back further a deep cold dam and before that in the hills, some high place w here a creek starts; a spongy bit of earth that's always green and damp

David Kelly

BIOBLOCK® Revolutionises Current Treatment Practices ADVANTAGES: • Inert Polyethylene Construction • Guaranteed Long Life of Material • Rapid Biofilm Development • Easily Installed • Large Surface Area/ m3 • Non-Clogging Guarantees Results • Self Supporting and Strong (12 ton/m 2) • Replaces Inferior Media AgentorTradeEnquiries:

Guaranteed Biological Solution APPLICATIONS: • All Fixed Film BNR • Submerged Aerated Filters • Submerged Anaerobic Digesters • 'New Age' Trickle Filters • Air Pollution and Cooling • Oil Separation • Wetland 'Roof Zone' Construction

LEYTON HOUSE INDUSTRIES PTY. LTD. P.O. Box 3002 Dendy, Brighton 3186 • Phone: (03) 9592 0024

42

WATER SEPTEMBER/ OCTOBER 1997


BUSINESS Abstract ¡ The keys to achieving sustainable development in the water industry are: tackling consum ption , re-valuing wa ter and wastewater services and improving and integrating planning for sustainability. We are consuming more water, more food and more energy than is sustainable and we grossly undervalue water to the detriment of our quality of life and the quality of life of future generations. W e must tackle consumption head-on so that we red uce it to the minimum level for good health and overall community quality of life. T he pollutant load in our wastewater is a . direc t co n sequence of o ur overconsum ption of foo d and other ma terials. Re-valuing water to perhaps $30 per kL by including ecological and social costs of human water use will be a key to encouraging reduced consumption. T he water industry cannot achieve a sustainable urban system in isolation from planning, transportation , energy, population control, economics, trade , commu nity services, employm ent and work, recreation and all the other facets involved in the integrated planning and decision- making that is a necessary part of ESD. W e m ust start planning for sustaina ble urban life within agreed boundaries.

A QUANTUM INCREASE IN

WATER PRICES J Crockett, L Carroll water infrastructure to urban areas, in reducing consumption and in avoiding discharge of was te m aterials to the sewerage system. Mu ch also needs to be done in irriga tion m anagement . Imperatives of ESD, including intergenerational and international equity, redirection of technology, integration of decision-making, control of population and elimination of poverty, also require action on the local scale. Whilst minor local progress is being m ade in minimi sing water use and wastewater generation, the world reality is increasing population water use and per capita waste loads. By the middle of next century, wa ter use may reach its ecologically su stainable global limit (Crocke tt, 1994) . Alrea dy there is ample evidence that some regions are exceeding their ecologically sustainable limit and the consequences for the environment are readily seen . Thi s paper develops the theme that we must do three things in urban water managem ent: tackl e consumption of water and materials; re-value water and water services upwards an d plan for su stainable cities within agreed boundaries.

forests and consequent gree nhou se effec ts, microclimate variation and effects on groundwater. Some of these effects may be seen as 'beneficial' but benefit to the environment has never been proven. Use of wa ter in gardens affects runo ff quality, groundwater and soil. All these effects are quite likely to damage the ecology of a region. Use in indu stry and in the home results in wastewater which conveys waste materials back into the atmosphere, land, groundwater and surface water. A wastewater system makes it very easy to waste materials and also hides th e wastage from view. Above all, an urban water system makes it po ssible for very large popula tio ns to live in small areas. This removes constraints on population growth , encourages . co nsumption and increasingly draws on resources from outside the region to provide energy, food, water and construction materials. Key Words Hi storical data on average yearly Water conservation , economic value water consumpti o n reveals that water of water, consump tion, waste minimiu se in a typical wes tern city ha s sation, wastewater generation, ecologiincreased during the course of the last cally sustainable development, catchcouple of generation s from arou nd 250 ment management, planning litres per capita per day in the 1920s (G utteridge Haskins and Davey, 1924) Introduction to the order of 500 litres per capita per Water Consumption and the The international imperative of day in recent times (ABS, 1994) . This achieving ecologically sustainable devel- Generation of Wastewater represents a rate of growth of around Harvesting and sto rage of water and 1.0% per ann um in per capita water opment (ESD) within the lifetime of our children and grandchildren is starting to water use in an urban area have many consumption. have a maj or effect on the way we significant environmental impacts. Minimum water requirements, water manage water (Crockett, 1994). Flooding ofland and variation of scream for a comforta ble existence and typical However, progress is far too slow and flow have widespread effec ts on biodi- water consumption for an Australian we have a long way to go to achieve versity, erosion, water quality, capacity household can be broken down into the sustainability: in the way we provide to assimilate pollutants, reduction of uses and quantiti es li sted in Table l. T his quickly identifies what little water we could use (and Table 1 Minimum versus current average household water consumption have used in the past) to run Typical Minumum Comfortable Historical Current Use our urban water systems. If we Requirement Requirement Consumption Design Design moved from fl ush toilets to (L/ Cap.Day) (L/Cap.Day) (L/Cap.Day) (L/ Cap.Day) (L/ Cap.Day) composting toilets we could 20 30 - 50 Drinking/cooking 5 ge t by with eve n less and Bathing 10 30 200 - 300 produ ce useful residues. Many Washing Laundry 20 10- 50 20 of the applications of current Washing Other 0 10 50 - 100 water consumption are said to Watering Garden 0 10 20 - 800 lead to improvements in terms of quality of life. But is this Dripping Taps 10- 30 0 0 really so? 20 - 50 15 Wash ing Dishes 10 attention Wo rl d was 20 30 - 70 Toilet 15 on water conservation focus ed 125 3901450 250 TOTAL 60 350-600 in June 1992 at the InterNote: L/ Cap. Day=Litres per ca pita per day national Summit on SustainWATER SEPTEMBER/ OCTO BER 1997

43


BUSINESS able D evelopment in Rio de J aneiro , Brazil, w here targets at a state, natio nal and global level were set fo r water use and co n serva tion. The action plan arising from th at Summit, known as Agenda 21, has set a fram ework for regulation and policy-making 111 relation to wa ter co nsumpti o n and wastewa ter generation. A key objective of the conference was that 'Water should be regarded as a finite reso urce having an eco nomic valu e w ith significa nt social and economic implications reflec ting the importance of meeting basic needs.' T he conference record also noted that 'global clima ti c change and atmospheric polluti on could also have an impact on freshwa ter resources and their availability .. .' and stressed ' the multi-i nterest utilisation of water resources for wa ter supply and sanitation, agriculture, indu stry, urban development, hydropower generation, inland fi sh ries, transportation, recreation, low and flat lands management and other activities.' As well as promoting wa ter con serva tion ac tiviti es, Agenda 21 pushes for 'development of new and alternative so urces of water- supply such as seawa ter desali natio n , artificial groundwa ter recharge , use of marginalquali ty wa ter, waste-water reuse and wa ter recycling. ' A base water consumption rate of 40 li tres per perso n per day has been put forward as a basis for individual wa ter supply needs. This co mpares to previo u sly co nsidered typical design rates of350-600 li tres per person per day that are curre ntly adopted for planning and design purposes. W hen wa ter is restricted severely, such as w hen we go to the bu sh on a camping holiday, w hat do we miss? T he craving for a drink of water is top of the list. After thirst, splas hing water o n our fa ces and washing our hand s probably com es next, but we can defer the latter and do the former with very little water. ¡It is surprising how little water we can

be sati sfied with w hen supply is limited. Perhaps 5 litres for drinking and preparing food. Perhaps 10 litres per day for washing ourselves , 10 litres per day for washing di shes and perhaps 40 litres every couple of days for washing our clothes . Thus we need perhaps 40 litres per day for essential purpo ses that we cannot or should not avoid. If toilet fac ilities we re ava ilable, an other 15 litres per day may be required. W hat does th e rest of the 200 to 1400 litres we use per day add to our q uality of life? We ca n have the aesthetic and health benefits of a waterborne sewerage system . W e can have an exotic garden . Our car can be shiny and clean. W e can watch television w hilst the dishwasher grinds away, inst ad of talking to the family over the washing up. W e can stand under a long, hot, fossil-fuel-co nsuming shower. W e can evaporate wa ter from our swimm.ing pools. W e can run 10 or 20 L down the sink w hile we clean our teeth . W e wash lots of things und er running water. Some of these m ore discretionary u ses of water add very little to our quality of life. So me add nothing. Our quality of life co uld remain as high , and in som e cases may even improve, if we consumed far less water. W hat applies in the home applies equ ally well in industry w here the same water-wasting habits lead to excessive use. W e can never invent a zero-waste process despite what the marketeers imply in their lobbying. Howeve r, humans are unique in their abili ty to prod uce waste at levels well above the thermodynamic minimum and then to make a business out of 'managing' the was te. From ove r-eating (whi ch directly increases the waste we excrete), to peeling the humble po tato under running water into our 'insinkerator', to running countless drafts of convoluted techni cal papers , we spend our lives wasting useful materials and adding to our waste management problems. By eating more than we need , by not scrap-

ing out the cooking pot before washing it and by using wa ter to chase useful product dow n the drain we individually contribute profit and problems to the waste indu stry . Our economic and indu strial system w hich is fo unded on encouraging consumption and redu cing unit costs with increasing consumption makes it very difficult to justify changing our prac tices to achieve minimum waste of materials.

Cost and Value of Water Table 2 summarises the co st of purchasing water from an urban supply authority and discharging wastewater to an urban sewerage system . The costs are based on published charges for indu strial consumers. The cost of water and wastewater services across Au stralia is similar and is trending to an even closer range as authorities introduce user-pays charging sys tem s and upgrade their systems to improve quality of water and wastewater. Included in the costs are the vari ou s headwo rks charges, annualised at 10% p .a., w hich most users pay in some way w h en they purchase a prop erty or develop an industry. In the wastewater charge per kL is included the per kilogram pollutant charges levied on industry. T hese have been calculated assuming industrial wastewater of three times domestic strength and one tenth domestic flow. T his is not uncommon for a larger city. Industries with higher strength wastewater will pay more. These costs per kL are low in terms of the value to the customer of the produ ct, services and benefits provided. T hese include quality oflife and protection of health and the environment. But they reflect all the costs of a water system. Whilst there will always be scope for continuous improvement of the efficiency of water service delivery, the authors believe that a significant part of the current emphasis on reducing wa ter service costs will prove to be misdirec ted effort and co unter-

Table 2 Cost of water supply and wastewater in Austra lia City

Water Supply Cost

$/kl

Melbourne Geelong Ballarat Bendigo Shepparton Wodonga Sydney Coast Sydney Inland Bathurst

44

Wastewater Collection, Treatment and Disposal Cost $/ kl

Based on Current Revenue

Based on Charges Levied

Based on Current Revenue Charges

Based on Trade Waste

0.94 0.81 0 .97

0.88 1.24 1.57 0.70 1.40 0.25 0.98 0 .98 1.08

1.68 0.52 0.91

2.01 2.36 2.49 5.11 0.54 1.03 0 .85 2.38 2 .04

WATER SEPTEMBER/ OCTOBER 1997

City

Water Supply Cost

$/ kl Based on Current Revenue

Orange Tamworth Newcastle Wagga Wagga Brisbane Toowoombah Ipswich Perth

Based on Charges Levied

1.28 1.32 0.91 0.74 1.26 2.45 1.23 1.24

Wastewater Collection, Treatment and Disposal Cost $/k l Based on Current Revenue Charges

f

Based on Trade Waste

2.13 1.79 0 .25 0.33 0 .50 1.59 0.46 0.65


BUSINESS produ ctive in terms of achieving ESD . Water use and wastewater disposal costs are not a major fa ctor in the cost of living and in the cos t of indu strial consumption . Thjs is illu strated by the fact that all water-related charges in a typical city account for only 1.4 to 1.8% of average hou sehold income or $600-$800/yr compared to average ho usehold income of $43 800/yr (ABS , 1994). In indu strialised societies we also spend very little of our time fe tching wa ter. Contrast this with subsistence economies w here a considerable proportion of a family's time is taken up with this vital activity. In developing countries families may well spend a considerable proportion of their income on water, and women may spend much of their time. If we have to or choose to buy wa ter from sources other than a water authority we will spend at least $10/kL to purchase it in bulk and over $1 000/kL to purchase it in bottles. This 1.4 co 1.8% spent on water services ca n be compared to other expenditure for food (10%), videos (0.5%), petrol (3-4%), the family dog (2- 3%) or a car (5-10%) . In these terms water is relatively cheap and therefore not a particular so urce of finan cial worry for the average family. From thi s qu alitative assessm ent, water appears relatively undervalued as a commodity in relation to the real benefits provided. Similarly, for the ave rage manufacturer , the cost of water for use in production is a small proportion of total operating costs. A typical range would be aro und 0.5% to 5% of total operating costs . Relative to personnel, raw material and energy costs , water is a cheap commodity for indu stry. T he cost of water to the consumer in many Western countries is so low that mo st people give little thought co redu cing water consumption.

Economic Value of Water Traditional economics and accounting take no deliberate accou nt of ecological and social values or quality of life in m easuring economic cos t of goods and services. To an extent these values are partly accounted for since the cost of co n se rvation , environmental protec tion , social services and the arts are built into the price of goods and services produ ced by a political unit. A new body of environmental economics is developing where the value of goods and services produced more deliberately includes ecological, social and quality of life values. These ecological and social costs include a wide range of costs of consumption and produ ction . Many countries are starting to run a separate set of accounts w hich factor ecological, social and quali ty of life cos es into the

final value of goods and services. T hese has been assessed for various uses in the parallel 'green' accounts are starting to United States (Gibbons , 1987). This be used in decision-maki ng by the more analysis co nsidered the user's willingadvanced governments. Australia is in ness to pay or alternatively the value of the process of setting up such acco unts. goods produced using water as an input. Examples of these ecological and social It valu es wa ter at th e order of$18 per factors include consumption of non- kL for residential purposes. renewable resources, air quali ty, area of An alternative estimate is that paid in arable land, water quality, life western societies fo r wa ter where a expectancy, biodiversity , working co mplete reticulation system is not versus leisure hours, population available. Wa ter cartage to a household grow th , freedom and equality and tank typically costs aro und $8 to $ 10 h appiness. These valu es should be influenced by the 'Quality of life will not reduce if we imperative for international and, even more i1nportant, more than halve our water use.' intergene ration al equity. Thus a new m easure of Gross National per kL. Bottled water, which is used in Product would bring to account the many developed co untries, costs aro und b nefi ts and costs of a wide range of 50 cents to S1 for a litre (equivalent to human and ecological fac to rs. $500 to $ 1000 per kL). M easurement of these in a cost/benefit On a national ba sis, the current cost accounting sense is not easy, but it is of urban water supply should be of the not impossible. order of $20 to $30 per kL if all the Until the 'new economics' seen by relevant social and ecological fac tors are Agenda 21 to be a necessary part of taken into acco unt. achieving ESD is in place it is diffic ult The consumption of water will be to properly define the economic value reduced by raising its price in line with of wa ter. M any of the ecological and co nventional demand-price elasticity . social cos ts th at will in future be Pricing water at $20 to $30 per kL to measured in determining the cost of refl ec t its tru e economic value would human ac tivity w ill no t be readily significantly affect the way in w hich we attributable to particular industries or manage water in our daily lives . It could products, just as the cost of government also provide funds to address the interadministration, suppo rting the arts, of national and interge neratio nal inour transport secto r and many other equities in availability and management services have to be at least partly fund ed of wa ter. from taxa tion. Th us, under a new economic system , all goods and services Three Scenarios will have an economic cost made up of There are three possible scenarios. both direct costs and general charges The first is that we truly tackle our that have to be spread across all goods profligate and burgeoning consumpand services. tion. We can do this if we choo se . For the water industry, direc t Quality of life will not reduce if we ecological and social benefits and costs more than halve our water use and of supply of water and wastewater wastewa ter discharge . se rvices in addition to those cos ts We can provide an incentive by currently acco unted for include: adopting the principle chat a town or • salination, erosion related to irriga- city should be self- sustaining within an tion agreed boundary. Within that boundary • energy use wa ter and energy resources, foo d and • improved quality of life due to water the ability of the environment to accept delivery to the consumer the was te inevitably generated will be • reduced biodiversity du e to irriga tion finite so the town or city co uld only of monoculcures sustain a given population. Setting up • fl ooding of land the boundary would require considera• reduced strea m flow tion of current population and once set • changed water quality it is likely that our cities of several • changes in forested area related to hundred thou sand co a few million will dam building or to catchment rehabili- be cons trained at their current populatation tions. Very large cities will have co • improved health redu ce population. This will improve • loss/gain of recreational facilities quality of life. • changed productivity due to irrigaIn the short term the cost of water tion and wastewater services will increase • changed productivity of water due to significantly as current expenditure has nutrient discharges to be spread over a reducing co nsump• advantage provided to urban dwellers. tion. In the medium term the eco nomic The quantifiable economic value of cost of water will reduce again as we water from a demand/output viewpoint avoid the need for new infra structure WATER SEPTEMBER/ OCTOBER 1997

45


BUSINESS and redu ce detrimental impa cts of human habitation . This scenario will require the will for tough legislation and planning controls to enfo rce the boundaries and preve nt una cceptable transfer across them. It will require us to radically change our behaviour as a community and as individuals and to reverse the current m essage we constantly give to o ur children that increasing consumption is good. This will require a quantum leap in economics, engineering and science, manufacturing, adve rti sing, taxa tion and political thought. If we include m easures of ecological well-being, quality of life and social well-being in GNP , we can increase our economic grow th w hile reducing consumption. The waste minimisa tion scenario is well established in regulatory circles world-wide and has taken roo t in the wa ter indu stry . Its emphasis is o n reducing wastage, w hich is not the same as redu cing consumption. The waste minimisa tion app roac h fa ils to tackle con sumpti on because o ur current economic system is based on growth in consumption. By fo cusing o n waste it fai ls to highlight consumption as the primary issue. In some parts of the world w hich are not too over-populated and which are well endowed with water resources the

'

waste minimisa tion scenario may give us an appearance of having achieved ESD , but it will no t do this in watershort areas. Thu s, it is argued that this scenario, in o ther words the current trend, will no t achieve ESD. This scenario is very close to current reali ty, since relatively few people in Australia and throughout the world are seriously conside ring the issues of ESD and some in power are actively opposing advances. The vast maj ori ty of the w orld 's populati on are either just surviving o r have embarked on an impossible consumption-driven road to economi c grow th and well-being. The fac t is that the maj ori ty of us are only paying lip service to the imperative of redu cing o ur con sumption . Even t.1o ugh we m ay be taking some measures to minimise waste, in o ur daily lives we are still increasing consumption. Our culture and our economic and political sys tem are supp orting thi s current lip service to achieving ESD . Funding of vital environmental ac tions is n ow dependent o n increased co nsumptio n of mobile telephone Gove rnment department service s. names are changing to re move words such as conservation. This third , and probably the current scenario , has no chance of achieving

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Conclusion T here are three fundam ental requirements for achieving ESD in the water industry. The first is that w e reduce to a sustainable level the consumption of water and of all materials that increase wastewa ter, including personal food intake . Waste minimisation is not sufficient in itself. W e need to fundamentally reassess our lifi tyle. The second fundamental requirement is to include ecological, social and quality of life fac tors in the value of water and wastewater services. Included in this new valu e must be the imperative of international and inter-generational equity and the costs of achieving this. With a more correct value of water and water industry services there will be an ince ntive to reduce consumption . Economic grow th in the water industry will be by increasing ecological and social values rather than by grow th in consumption and by improvements in water quality. The third requirement is to plan our water systems on a regionally sustainable basis within given boundaries and to integrate water planning with all o ther critical aspects of urban planning: energy and fo od supply, transportation, population control, employment, recreation, communications and community services. Planning should be for sustainability of supply of water, energy and materials within an agreed boundary. This has fundamental implicatio ns for the stru cture and functioning of government in the future .

References Au stralian Bureau of Statistics (1994) Year Book Au stralia 1994, Au stralian B ureau of Stati stics, Canberra. C rockett J A (1994) E cologically Sustainable D evelopment: Implica tions for the W ater Industry, AWWA 16th Federal C onv. G ibbo ns Diana C (1987) The Economic Value ofWater,. R esources of the Future: W ashington D C. G utteridge H askins & D avey (1924) R eport on the W ater Supply of the C ity of Hobart, Gutteridge H askins & Davey, M elbourne. Ploeser J ane H (1996) C onservatio n and the Industrial C usto m er , AWWA J ournal , Janu ary 1996 , 65-69 . Sto ne B ria n G (1978) Suppression of W ater U se by Phys ical M e thods, American

Water Works A ssociation]ournal,70.

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WATER SEPTEMBER/ OCTOBER 1997

United N ations Conference on Environment and D evelopment (1992) Age nda 2 1 P rogramme of Actio n for Sustainable D evelopmen t, UNCED ,

Authors Jonathan Crockett is Manager , W ater T echnology and Leon Carroll is a Civil Engineer with Gutteridge H askins & D avey, 380 Lonsdale St, M elbourne , Vic 3000 .

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Water Journal September - October 1997  

Water Journal September - October 1997