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Volume 30 No 8 December 2003 Journal of the Austra lian Water Association

Editorial Board F R Bishop, Chair man B N Anderson, W J Dulfer, G Finke, G Finlayson, GA Holder, 13 Labza, M Muntisov, P Nadebaum, J D Parker, F Roddick, G Ryan, S Gray, A Gibson

', Water is a refereed journal. This symbol indicates that a paper has been refereed.

OPINION 2

Harnessing the Energy; Rivers Forever; My Point of View, An Ocean Outfall Strategy for Australia, G Hu nt

ASSOCIATION ACTIVITIES 6

Including IWA Australia Report and WEF Report

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12 Details of courses, classes and other upcoming water events

NEWS BYTES

Managing Editor

13 Featuring selected highlights from the AWA Email News

P eter Stirling

CROSSCURRENT

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16 National Water Initiative; Murray-Darling Basin Ministerial Council - Communique

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C hris D avis Australian Water Association (A WA) assum es 110 responsibility for opinions or statements of facts expressed by contributors or advertisers. Edito rials do not necessarily represent official AWA policy. Advertisements are included as an information service to readers and are reviewed before publication to ensure relevance to the water environment and objectives of AW A. All material in Water is copyright and should not be reproduced wholly or in part without the written permission of the Managing Editor.

.:. AGRICULTURAL USE OF RECYCLED WASTEWATER: HYDROGEOLOGICAl MODELLING Will recycled urban water downgrade the groundwater? N J Aru naku m a ren , P A Eva n s

29

Water (ISSN 0310 • 0367) is published eight times a year in the months of February, March, May, J une, August , Septem ber, Novembe r and December.

,:_ GROUNDWATER CONFLICTS: HOW WAMPS CAN HELP Can even farmers agree to a management plan?

WATERWORKS Articles contributed by the Water Operators Industry Association including odour detection, pH buffering, use of wetlands to treat sewage and HACCP issues.

WAtER S9

•, COPPER PIPE CORROSION: A WATER INDUSTRY PERSPECTIVE Blue-green water: still a mystery G Ru ta

64 LOOKING TO THE PAST Our earliest water resource engineers H Bandier, r E A Bayly

ENVIRONMENT 66 WATER QUALITY MONITORING: AN OVERVIEW Information for non-experts P M aide n, D Bryan t, A Gibson

BUSINESS 70 RECLAIMED WATER: MANAGING THE LEGAL RISKS Potential sources of legal liability L M oore

WASTEWATER 7S

•, WASTEWATER MANAGEMENT AT SHEPPARTON, VIC Trade waste agreements lead to sustainability A Jovc ic, A Tyson, B Ha mmond

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OUR COVER: ltrlm1d Waters: Prefessor Bill Williams started li111110/ogy strrdies at Mo11aslr U11iversity the 6Os (Iris paper 011tire "Disti11ctive C/iaracteristics of A rrstralian Inland Waters" was published tire first issue ef 'Water', 1974). A 11101111111e11t ro Bill has recently been unveiled at Lake Cormrgamite, at a ceremony attended by tttatty li111110/ogists. Dr Ian Bayly, until recentl y 011e of tlrose Mottash li11tnologists, travelled 11Jidely around Arrstralia and Ire lras rrsed his lrobby ef photograph y to amass a tttagnificettt collectio11 . Our cover picture is ef m1aboriginal rock-lrole, an important resource fo r clmts living away fro m our eplre11teral rivers. See tire paper 0 11 page 64. Photo by I A E Bayly. i11

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FROM

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PRESIDENT

HARNESSING THE ENERGY W hat never ceases to amaze me on my travels around the country is the enthusiasm of members and their desire to help. Members have made this Association great and their continu ed support wi ll enable it to grow in all sorts of w ays . Our Branch Commi ttees deal w ith members at the grass roots level and work away tirelessly organ ising events and generally lo oking a fter members' interests. Progressively the larger Branches have moved to engage local office managers to assist in the day-to-day man agement of events and members' needs. Experience bas shown that this invariably leads to a significan t expansion of services o ffered to m embers. The most recent m ove in this regard is the Western Australian Branch that now has a part time Events and Marketing Coordinator, Cathy Miller. In the case of the Western Australian B ranch it bas elected to employ som eo ne with marketing skills specifica lly to raise the image and profile of the Association . Funding fo r this in itiati ve, as for a previous similar initiative with the South Au strali an Bran ch , w ill be in pa rt contributed from th e national coffers.

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Rod Lehmann

Th is leads to the question of w ho pays for what and who is responsible for what? This is increasingly becoming more bluned. It is clear that we need to m ove towards a centralised budgeting system to pro vide our Directors with the information that is needed fo r them to properly fulfill their duties and to remove som e of the in1pediments to efficient financial management and th e occasional conflicts that arise between national office and Branches. There are also various fi nancial deals made by B ranches for which the Directors are ultimately responsible. Directors rightly need to be made aware of the risks and li abilities associated with such deals. R emember each Branch bas a D irector on the Board , so it is not a big brother syndrom e. Abo ut a year ago our Past President Barry Norman bad the temerity to suggest that we sho uld be moving to a centralised budgeting system. 'Over my dead body' , l mumbl ed then. M y main concern at the time was to preserve the strong drive and enthusiasm that co mes fr om self-manageme nt. Somehow we will j ust need to make it work if we are to move forwa rd. l will keep you informed of progress. Before the last AW A Board M eeting we held a one-day training session on the resp onsibili ties of di rectors and best practice in governance of not-for-profit ass ociations like AW A . T he session brought to the for e a number of oth er challenging questions about how we m anage our affa irs. Th e cu rr e nt arrangement consists of a Board and E xec utive Committ ee . When A WA operated fundamentally as a volunteer organisation (from 1962 until the mid-70s) an Execu tive Committee was just that it had to do things, or the operation founde red. W e've clung to that structure ever since, but its utility in a phase w here we now have quite good staff resources was

put under a spotlight . The Board is som ewhat disenfranchised by a group that operates in between its m eetings (at ¡ present, j ust twice a year) so there's some uncertainty about roles and responsibilities. Corporations Law, however, lays th e responsibility squarely at the directors' feet, so the final answer has ¡ to be that the directors are in charge . In addition to clarifying the role of the Executive Committee, at a Board level we need to separate operations from governance. The Board governs, the national office operates. T he trouble is that we are still an Association very d ependent on member help; members sometimes work in governance roles and sometimes in operational roles. No problem with this as long as we are aware of what we are doing. I expect that members will always be doing part of the work as this ensures a hea lthy organisation that is dri ven by enthusiasm and passion . What we need to aware of, though , is when the things we do are under the con trol of the Board and w hen they are under the control of staff, and this impacts on the management arrangements. T he outcom e of our deliberations was an agreement to rethink what we are doing and how. We will need the full cooperation and support of the Branches to achieve the change that is necessary and so we propose to review the issues w ith each Branch prior to m aking any decision at Board level. We believe that there are many issues that were brought forward at th e training session that are entirely relevant to the way the Branches operate. For this reason we would like the Branches to benefit from the sam e opportunities that were provided to the Board and are therefore currently looking at how th is may best be achieved. Following the Board m eeting we held the Annual General M eeting. As usual , only a small nun1.ber of m embers attended. I take this to m ean that there is gene ral support for the way we are doing things. This is positive I believe. After the m eeting I was fortunate to spend some time with Roger Pettitt. H e was still in good spirits at the time, despite a downturn in his prognosis. He passed away about two weeks later. I was most saddened by the news, as were all his fri ends and colleagues. I always enjoyed talking to Roger as he presented things w ith a w armth and sense of humour and he always m anaged to put an interesting, negatively positive slant on things. His contributions to the Association are much valued. Rod Lehmann


ID

GROUNDWATER

GROUNDWATER CONFLICTS: HOW WAMPS CAN HELP H Diwakara, J McKay Abstract Groundwater in Australia in many areas is an open access resource regulated in a minimalist way. Thus conflict resolution in groundwater management has different attributes to schemes devised for smface water and there are fewer examples in the world literature. T his case study looks at an unregulated aquifer w here there is a serious community conflict. According to the older agricultural users the decline in groundwater access is due to 20 years dewatering by a mining company. This paper reports on the responses of the community to a suite of new policy options such as water managem ent plans and their attitudes and willingness to join in this process. T he results show that growers in the most blighted zone (where their wells are now d1y) are willing to join a water allocation and manage ment plan, W AMP (now water resources plans, WRP). W e conclude that if such a scheme is initiated in th e area and includes groundwater then this m echanism will be posi tiv ely rece ived and provide an important m echanism to resolve this water allocation and use conflict . Key Words: Groundwater, Water Allocation Management Plan, Australian Water P olicy.

Introduction Groundwater depletion and surface water allo cation conflicts are common fea tu res in ma n y co un t ri es . Water resources plann ing regimes are now recognised as extremely complex systems and in Australia the attributes of these are still ill defined (M cKay 2003). There are m any more stake holders and conflicts between them will increase as population grows. There has been a massive reform of water management regimes but there are many conflicts over property rights and compensation (C hief Execu tive Officer's Group on Wate r 2003) . Australia has begun to address ground and surface water supply problems by innovative water policies, institutions and planning processes including the creation in every state of water allocation plans. These plans involve all lo cal and state stakeholders in present and future water allocatio n decisions. In the past there has been little o r no cost recovery from the users of irrigation

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water. Thus Governments do not have the resources to implement new schem es. Acco rdin g to CoAG Groun d water R eforms (1996) full cost recovery is one of major components of water pol icy reforms in Au stralia. In Q ueensland, full cost pricing has bee n introdu ced for local government water suppliers for large entiti es. H oweve r , n ot al l lo ca l government water and wastewater service providers are operating on a commercially viable basis as defined by the CoAG pricing guidelines (National Competition Council 2003). Of125 local governments in Queensland, all but six have committed to implem ent full cost recove1y reforms by June 2003. However, in practice it is difficult to impose a hu ge increase 111 charges on users. This article prese nts the results of a survey conducted to assess the willingness of farming community to join a water allocation management plan (WAMP). The farming community is located in East End in the Mt.L arc om region o f Queensland near Gladstone (see Fig.1). The results of this survey could be generalised to the farming communities facing similar water conflict problems.

Lack of WAMP and Groundwater Conflicts The region has not had a water allocation plan, so groundwater has bee n and still is extracted and used in an unlimited way. No paym en t was ever made for th e actual raw water used. This is a classic exampl e o f tragedy of commons. According to the farmers, the main reason for groundwater depletion and variable quality degradation (salinity) is the activity of Queensland Cements Limited (QCL), w hich extracts gro un dwater from the deeper layers of the aquifer to dewater its mine. This has happened since November 1979. The water is discharged downstream as waste . W hile the payoffs from this activity are lucrative for the industty the negative economic externalities arising o u t of this are pervasive and are unabated . The dewatering has lowered th e aquifer, so many of the old wells do not have water. Groundwater depletion had manifold impacts on the local economy su ch as (1) d ecline in agri cu ltural produ ction, (2) reduced water for stock, and (3) decline in land values . T he extent WATER DECEMBER 2003

23


GROUNDWATER

of the latter loss is signi ficant, fo r pre- tested in the locality and Q. Rank the importance of Groundwater Depletion in Mt.Larcom instance, some farm ers have lost then interviews were conducted their property values by up to by telephone. El Most fmportant 50 percent [e.g. According to 100 I n order to inform the a Moderately lmportant ACVAL T urner Valuers, 1998, 90 respondents about the research, Clmportant ,,, the Lashford family in East End 80 o ffi c ial lette rs were mailed â&#x20AC;˘ Least Important C: 65. 1 whose property value before a Not Important at all before the interv iew was "8" 70 ~ water depletion w as $280,000 a Don't k.now / refused 60 conducted. The survey included p,: for 114 hectares is now worth ....." 50 open-ended questions regarding 0 40 $92,500] . In addition th e probl ems faced by t he C: earning ability, potential, and "~ 30 community and their willingness & 20 value of the land has been to join WAMP. Of a local 10 damaged, and there is a population of93 households 63 0 widespread blight on saleability, households responded at East which was recognised by the Importance of Groundwater Depletion E nd, Mt.Larcom. This repreLand Court Queensland (2002) sented about 68 percent of the Figure 2. The significance of groundwater depletion in East w hen it reduced the valuation t otal population but the End, Mt. Larcom. of properties in the East End. remainin g 32 percent respon[Case: the Land Court decision Queensland Cements Limited (QCL) dents did not answer the calls . in the matter of an appeal against a and supported by Government Agencies The data are analysed usi ng simple tabular valuation property ID 8 16602, in the to assess local aquifer circum stances . an alysis and chi -square tests. Calliope local Government, the clients Smith declared that the standard modeling Results involving (i) Alec E. Lucke & Ors procedure for granular darcian flow is an (A V2000/0196), (ii) Peter B & Lynette unsuitable methodology for a karst aquifer We asked the respondents to describe Brady (A V2000/0 196) and (iii) Arthur W with conduits. Smith concluded that th e t h e probl e ms facing the farming Murphy v Chief E xecutive, Department main causes of surface and underground community and to discuss them. and of Natural R esources and Mines (hearing water loss related principally to mine present thei r views rega rding a set of at Gladstone). The major reasons for the dewatering, which in volved discharge of solu tions. decision to lower the land valuations were the water downstream as waste without The respondents ranked th e ground(i) adverse effect of QCL on community returning it upstream to the min ed water depletion problem as most i111porta11t and land valu es, and (ii) general deterioaqu ifer. Smith acknowledges drought because groundwater irrigation is the ration of the area due to lack of services]. and its impacts but does not regard lifeblood of the farming community in this drought as a valid explanation for unpreceImportance of WAMP region. Only 9 .5% of res p ondents dented water loss proven by the water considered it 111oderately importmlf and those Australia is currently grappli ng w ith the monitoring data for the last 5 years (Smith w h o considered it least i111porta11t were a issue of who has right to use what water, 2003). miniscule of 1.6%. This clearly reflects that when and how, since many system s have the grou ndwater depletion is a key cause Method been over-allocated (M cKay 2002 and of concern (see Fig.2). 2003). This has serious equity implications In the survey of all farmers the objecsuch as, co nsum pt ion of water, tives of th e stu dy were (i) to analyse the Perceived Solution downstream impact of water, as well as impact of groundwater depletion on the Gro undwate r depletion is a major local economy due to mining activities by land and ecosystem q uality. In such areas predicament in chis region and growers identify ing the predicam ents faced by the WAMP (or WRP) could be a valuable blame the mining operations. Many of the growers in the affected area and (ii) to instrument for creating new rules for growers feel that not mu ch has bee n done esti mate the willingness to join a water sharing water between users. Another issue for their welfa re. T he majority of the allocation management plan (and to is the a ll ocat ion of water to the growers (74%) fee l t h at t h e State describe the characteristics of respondents environment, so mething the previous government should take corrective action and their attitudes to water p olicy change water allocation processes did not consider. to protect the interest of the fa rming in Queensland. The questionnaire was community in th e Mt. Larcom region. East End, Mt. Larcom, with regard to responSimilarly, example Q. Who Should Take Correct ive Action? sibility to corrective ac tion, 41 In this section we provide a % indicated local government, D Local Govern ment description of the study area 30% indicated that it was every D Environmental Protection Agency indi cating the groundwate r citizen's responsibility to act, 100 D State Government depletion problems. Members 27% indicated the environ80 of the c ommun ity firml y c"' D Every Cit izen o f East End mental protection agency (E PA) "8"0. believe that the mine is responand 14% of the respondents 60 ;;'l sible fo r the water depletion declined to comm ent. Some ~ .... problems. 0 40 growers have indicated more c In the water audit conducted t h an one agency to tak e "~ 20 27 by Professor David In gle Smith Q. correction actions. This clearly " (2003) for the Mt Larcom i ndicates that the gro,vers Commun it y R esto ra t i on perceive t h at t h e onus of Agencies Responsible for Action Project, he reviewed the model managing the crisis of grounddeveloped by D r Frans Kalf for Figure 3. Farmer's Perception on Corrective Action. w ater de pletion due to mining 24

WATER DECEMBER 2003


GROUNDWATER

for both agricultural and allied activities (stock, piggery, poultry and so on) Allocation Management Plan? it may be worth tradi ng water from 6% surplus areas to mitigate the groundD Yes water scarcity wh ilst providing water 33% D No Willingness to Join a WAMP for inigation. This can be realised only DRefused when a clear defi ni tion of formal R espondents h ad h eard of property rights to water is m ade with WAMPs from neighbo uring regions Figure 4. Willingness to join a Water Allocation an emphasis on defined volume of and 61 percent of respondents saw the Management Plan . water, reliability and transferability and mechanism of a W AMP as a positive (AMCANZ 1995; Brennan and quality innovation and were will ing to join vegetation and staying on the land. A vast Scoccimarro 1999). T o overcom.e these such a process (see Fig.4). The WAMP majority (about 43%) of fa rmers were probl em s it is possible for government to process would license all water users and ready to continue the fa rming despite lack make an arrangem ent in the form of involve community participation in the of groundwater fo r inigation, 33.3% of the suppl y of water for at least small-scale li ce n se all ocation d ecis ions. [The responden ts preferred to stop the farming Queensland Water Act and the Mining and stay on their land, and about 8% of irrigation by initiating a cost-sharin g Act is of very wide ambit as Sectio n 10 th e responde n ts prefe rre d co pl an e scheme conforming co the full cost recovery principle of CoAG . This could of C hapter 2 demonstrates] . The Act deals vegetati on and stay on their land and 8% include providing som e funds to drill new w ith making of water plans and land did not comm ent (see Fi gu re 5). wells, bearing in mi nd a sustainable use managem ent plans and sets out criteria fo r Implications of the Survey regim e. Cost-shating arrangements to deal approval and the informatio n to be with conflicts in volving natural resources produced if required. It is clear th at The Queensland Government w ilJ conservatio n exist in many other places. WAMPS will (i) improve planning confifind community support fo r a W AMP in Fo r instance, in Kansas, Federal and State dence of water users now and in the future this area. There is no water a!Jocati on governments fund gro un dwater conserregarding the availability and th e security policy or plan in Mt.Larcom; however the vation assistance programs implemented of water entitlements, (ii) provide fair, sustai nable yield of the groundwater through local government units (Kansas orderly and efficient allocation of water managem en t units has been estimated to Water O ffice 2000). Th e costs are shared to m eet co mmunity needs, and (iii) be 2000 ML per annum (Au stralian increase the community's taking an active W ater R esources Assessment, 2000) : of between Federal and State governments and participa ting farmers. For example, part in planning the allo cati o n and this 56% o f groundwater is extracted by participants in higher priority areas receive managem ent of water. Th is clearly reflects QCL alo ne (Brady 2001) . In order co a greater level of support. The cost-shating that a vast majority of the farmers is willing pro mote agricultu ral and all ied activities is, (i) to decrease the usage of water, (ii) to join W AMP if the area is brought under and social sustain ability in the region, insta!Jacion of water m eters and innovati ve WAMP. We believe that the reason for water allocatio n and water resources plan programs such as water right bankin g in willingness to join WAMP co uld be (i) co uld be initiated as most farmers have which a reduction in actual water usage protection of the reso urc e and (ii) indicated their willingness to join such a is requ ired and (iii) provide cost-share provision to se!J their water entitlem ents plan if initiated. nts to farmers to try inn ovative, gra and/or rights through selli ng their license lt has been recomm ended by the en vironm ental friendly, low water use to others and make money. However, this Nat u ra l R eso u r ces Man age m ent, cropping and livestock practices, i.e., can onl y be real ised if there are potential Ministerial Co uncil 's C hief Executive changing land use. buyers of their li cense. Officer's Group on Water that CoAG In Australia a similar approach has been In order to test the statistical signifi endorses a national sec of principles fo r attempted in South Australia in the can ce of j oining a W AMP with respect water allocation and entitlements and a set Mall ee P rescribed Wells A rea and to age, edu cation and income of the of guidelin es for provision of adjustment T intinara Coonalpyn Prescribed Wells respondents chi-squared valu es have been assistance where cha nges are made to Area. Here there are successful costca lculated. The resul t indicated that age water entitlem en ts (National C ompetition is signi ficantly rela t ed to grower's sharing arrangem ents to settle disp utes Council 2003) . T h is plan could address willingness to join a WAMP. You n g between irrigaco rs' use on crops and their cos t -s h ar in g plans a nd reso u rce people are more willing to join a W AMP . use for dom estic purposes. (D iwaka ra et management plans. al 2003) . This sc heme is initiated on the Of those willing to join a WAM P, 84% Other suggestions for policy backdrop of groundwater drawdown due were under 40 years old. Water markets co uld be a co mponen t to increasing irrigati on and irrigators have H owever, education leve l and incom e of any plan to increase access co those who contributed to a cost-sharing scheme to of the respon dents are not significan t need water. There are currently no water adjust the water supplies for themselves in factors related to willin gness to join a markets in the Mt.Larcom, however, since their stock and domestic licences. The WAMP (see Table 1). there is an increasing demand fo r water of irrigation in the areas has been increase The far mers in the region are keen to d ee m ed env ir o nm enta ll y stay in the region but in sustainable but it has left the the even t of no water Table 1. Relationship between Age, Education and Income and shallow wells used fo r domestic being availa bl e for Willingness to join a WAMP (Chi-squared values). supply to each farmer's house irrigation they we r e stranded. Since the natu re of the asked which option they Age Income WAMP Education problem (g round water would choose (i) leaving Ch i-square 6 .18 3.23 4.32 dr awdow n ) is s imil a r in fa rming and staying on 2 4 4 Degrees of freedom Mt.Larcom district, governm ent their land, (i i) continue Not Sign ificant Not Significant Leve l of Significance 95% th ro ug h its regulation could farming, and (iii) planting

acnvm es in this region falls on the State government (see Fig.3). T he mechanism intended fo r this purpose is of course a WAMP.

Q. Would you be Willing to join Water

WATER DECEMBER 2003

25


GROUNDWATER

initiate cost-sharin g arrangements to provide an alternative supply of water to the blighted farm e r s all t h ro u gh t h e co1m1rnnity mediated W ater Allocation Plan Managem ent process. We outline some key elements of an ideal successful cost-sharing arrangement in Box 1.

AV2000/0196, AV2000/0264, Alec E Lucke and Ochers v D epartment of Natural R esources and Mine. â&#x20AC;˘ Don't know /refused M c K a y, J e nnife r ( 2 00 2 ) . C Planting vegetation and staying on the Land Encountering the South Australian Cl Continue Farming Land scape : E a rl y Europ ea n </> C Leaving Fam1ing and staying on the Land C: Misconceptions and Our Present 0 ¡o Wate r P roblems. H awke Institute, 42.9% Working Pape r Se ri es No. 21, University of South Australia. 33.3% M c K ay, J e n n ife r , (2003) . " Marke ti sat io n in A ust r alia n Fr es h wa t er an d Fi s h e ri es An ideal cost-sharing 0 50 100 Management R egimes, in Stephen Percent of Respondents scheme for sustainable Davers and Su Wild Ri ver (eds), groundwater use Managing Australia's Environ men t, Figure 5. Alternative Options in absence of Irrigation in East The Federatio n Press, ISBN l 86287 In Mt Larcom a cost-sharing End , Mt .Larcom. 447 6 schem e, if fram ed and impleNatio na l Compe titio n Co uncil, C ouncil o f Australian Govern ments, 1996, m ented , w ould no t only h elp to resolve (2003) . The 2003 N ational Competition Grou ndwater R eforms, Canberra AC T. dispute it would also encourage the Po licy Assessment Fram ew ork fo r Water CSIR.O, (200 l) . Water U se in Australia, R eport co nservation of water. T he ado ption of R eform, M elbourne , Victoria. I of IV in a series on Australian water fu tures, Q ueensland Water Act, 2000 d o wnload ed from limited market m echanisms may then be Resources Futures Program, Canberra. http://www.austl ii. cdu.au/ cgi-bin/ disp. pl/ used to provide access for new users C hief Execu tive Officer's G roup on Water, au/legis/qld/ consol%5 fact/wa200083/?query subj ect to localised tests as the sustainabl e (2003) . N atural R esource M anagement =title+%28+%22water+acc%22+%29 . Min isterial Council. R eport to the Council use of each new well o r increased use of S111ith, David Ingle (2003). Mt. Larcom Surface of Australian Governments. an existing well. and Grou ndwater H ydrology: A R.eview Diwakara, H . McKay. Jennifer and Barnett, Steve pre par ed for M t.La rc om Co mmun i ty Acknowledgements (2003) . "Cos t-S h arin g as a T oo l in Restoration Project, Mc. Larcom, Queensland G ro undwater Managem ent Policy-Some T he authors thank the following people 4695. Internacio nal Experie nces", paper presented and organisations fo r their assistance and T urner Valuers, (1998). Valuation R epo rt of at the 1 1th World Water Co ngress, 5-9 encouragement; Farmers of East End, Mt. Las h fo rd's P rope rty, Eas t End R oad, October, M adrid, Spain . Larcom and East End M ine Action Group Bracewell, East End Mine Action G ro up, Gladstone Arca Promotion and Development Ltd. M embers, Kirsty Willis an d staff o f Q ueensland 4695. (2002) . Dem ographics, Statistics, R esources

Q. If there is no Water for irrigation what options would you choose?

o'

Marketing Science Centre, University of South Australia, Alec Lucke, Peter Brady, Professor Brian R oberts (Qu eensland), Professor Da vid Ingle Smith (Canberra), and D r. Lalith Achoth (India). This study was funded by a grant fro m the Federal and R egio nal Solutions Program me to the Mt Larcom East End community fu nd. known as the Mt.Larcom Conrn1Unity Restoration Proj ect.

References Agriculture and R esource Managem ent Council of Australia and New Z ealand Standing Committee o n Agricultural and R esource M anagem ent (AR.MCANZ) (1995) . Water A lforatio11 a11d E11 titlr111c11ts: A N atio11al Fra111ework for /111plc111e11tatio11 '!f Property R(~l,ts i11 Water, Policy Positionfor disc11ssio11 wit/, srake/,o/ders i11 de,,clc>pi11i a11d i111ple111en ti11g syste111s <if water allocatio11s a11d e11title111w ts, Taskforce on C oAG Water Refo rm, Occasional Paper No. 1, Canberra ACT. Austra lian W ater R esources Assessment (2000) . Natio nal Land and Wate r R esou rces Audit, Natural H eritage T rust, Canberra ACT . Brennan, D and Scoccimarro, M. (1 999). " Issues in de finin g property ri gh ts to im p rove Australian wa ter markets", A ustralia11 Jo11mal <if Agrimlwra/ a11d Reso11rce Eco110111ics, 43 (1): 69-89 . Brady, Peter (200 I) . Detailed district irrigation usage versus mine pump out fi gures an d revised mo re informative table in Golder and Associates-J o h n Wa terho use report o n Addendum to review of hydrological impacts, Ease End Mine Actio n G roup Inc. East End, M t.Larcom, Q ueensland, 4695.

26

WATER DECEM BER 2003

a nd Infrastructure, G ladsto ne R egio n O verview, Gladstone, Q ueensland. H all iburton, Kl3R . (2002). D iscussio n o n Com 111un ity Attributes, H EN20 1-00 I- DO001 R evie w Co mmi ttee, M t.Larco 111 , Q ueensland, 25th September 2002 . Kansas Water Office (2000). Commi ttee R eport o n Fede ral Actions Necessary for the Conservatio n and Environmental Preservation of the High Plains Aquifer, October 27th 20 0 0 (dow nlo ad e d fro m ww w .k wo . o rg/ R eports?comm_ Rpt_plains_Aquifcr. pd~ Land Court, Brisbane, (2002) . " R e appeal against an nual valuatio n"- Valuatio n o f Land Ace o f 1944, Shire of CaUiope, AV2000/0163,

The Authors H. Diwakara is a PhD Scholar, and Member o f th e W ater Policy and Law Group at th e School o f Interna tio nal B usiness , U niversity of South Au strali a, No rth T errace, Ade laide, SA, 5000 (Emai l: diwakara .halanaik@unisa .edu.au). Jennifer McKay is a P rofessor of Business Law and D irector of the Water Poli cy and Law G roup , U niversity of South Australia (Email: j enni fe r. m cka y@ u nisa .e du .au, http :// www . b u siness . u n.i sa . ed u .au / waterpolicylaw) .

Box 1. Key Elements of an Ideal Cost-Shari ng Scheme 1. Maintaini ng adequate yield to access t he groundwater by making cost adjustments 2. Funds are provided for (i) Lowering pum p(s) (ii) Upgrading pumps/ mi ll(s) (iii) Deepening existing well(s) (iv) Drilling new we ll(s) (v) Decommissioning old well(s) (vi) Changi ng t he water supply plan of a property 3. Requires participation of all. stakeholders 4. Fu nds should be raised from licensees 1hrough levy on water allocation 5. All li censees should contribute to the costs of adj usting stock and domestic water supplies 6. Involvement of loca l water user in administering the scheme Note: Only dot points are provided. For detail see reference below. Sou rce: Diwakara, H, Jennifer McKay and Steve Barnett (2003)


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GROUNDWATER

AGRICULTURAL USE OF RECYCLED WASTEWATER: HYDROGEOLOGICAL MODELLING NJ Arunakumaren, PA Evans Abstract R ecognition of the potential value o f urban waste water to supply irrigated agricultu re is increasing througho u t Australia. Regulatory sc rutiny o f such proposals now embraces considerations of sustainabili ty from th e perspective of management of groundwater level and quality requ iring reliabl e pred ictiv e groundwater models. What is important to su ccessfu l assessm ents is adequ ate conceptualisatio n of the areas to b e modelled prior to co mmen cement of m odelling; achieve ment of catchmentscale m odelling rather than paddock scale modelJing; and then the processing of th e model outputs to spatially ide ntify risk areas. T his paper describes such assessment in two regions of South East Queensland., the Lockyer Valley near Bisbane and the Pioneer Vall ey near M acKay. Models predict that sustainability is poss ible subject to certa in conditions. Keywords: wastewater; irrigation; Lockyer Valley; Pioneer Valley; M ackay; sugar can e; groundwat er; modell ing; salinity; nutrients

Introduction The use of treated recycled water so urced from urban WWTP's offers terrific opportu nities in a water sh ort country such as Australia, particularly where conventional sources are alread y fully or over committed. In som e cases potential exists to "free up" higher qu a lit y water s uppli es through replacement w ith recycled water to enable the hi gher quality water to be applied to higher value use. Further, there is potential to lower fertiliser inputs w ith increased effi ciency du e to nutrient content of the recycled water The use of recycled water does however have some appreciable potential problems. All irrigation activity has potential co alter established hydrological This paper was presented at the AW A Victorian B ranch C onference, Lorne, October 2003 .

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mencs and financiers of such schemes. It is also important because there are limitations to th e reliability of more traditional sustainability evaluations that use histotical soil and groundwater data. In extreme cases when little or no historical groundwater data is available, model predictions all ow grou ndwater level ranges to be evaluated. One of the most valuable appl.ica tions to pred ictive groundwater modelling is th e testing of complex scenarios to evaluate the "what if?" questions to allow optimisation of schemes through the testing of a series of alternaci ves.

Figure 1. Locality of study areas.

Part 1. Lockyer Valley Hydrological Study

balances. Gro undwater recharge ca n be enhan ced th rou gh altered soil moisture conditions and via excess irrigatio n application. Enhanced recharge can induce long-term groundwater level rises that can, in certain circumstances, lead to waterlogging and salinisation of agricultural land. Further there is potential for groundwater co ntamination by salt, nitrate, pathogens and trace contaminants (eg metals) to occu r. Contamination of stream s and lakes from both runoff and groundwater discharge is also potentially possible. Th e host soil itself can potenci all y b e adverse ly imp acte d and d epending on th e chem istry of the applied water and the soil characteristics, soil structure may be adverse ly impacted (eg. cation exchange impacts from high SAR water). Impacts from surface run off require consideration of a range of factors including water quality, soil and crop type and farm management. Such impacts are generally assessed using water balance models and surface water modelling packages. Soil structu re and fertility impacts require specialist inpu t from agronomists and so il scientists R eli able predictive modelling is imp ortant because confidence ch at recycled water schem es will not produce unacceptable environm ental ou tcom es is necessaiy to secure the supp ort of govern-

A significant opportun ity to use recycled water efficientl y in south-east Q ueensland to support agri culture has b een identified by State and Loca l government in the South East Queensland R ecycled Water Project. T he key drivers of this opportunity are a shortage of water supplies of suffi cien t quality and quantity that limit the economic growth of the Lo ckyer Valley, Bremer R iver & W arrill C reek Valleys and the Eastern Darling Downs and issues surrounding the current disc harge o f treated wastewater to the Moreton Bay and associated coastal areas. The Lockyer Valley catchment is situated in so uth -east Queensland and forms approximately one quarter of the Brisbane River catch ment. It has an area of 295,400 ha (2,954 square kilometres) l ocate d between Ip sw i c h and Toowoomba. The study area for the hydro logical assessment covered approximately 28,422 ha and the locality of the study area is provided in Figure 1. The Lockyer Va!Jey is the 'salad bowl' of South East Queensland producing crops mainly from valley floor all u vium w h ere extensive irrigation occu rs from a major allu vial aqu ife r. Th e Lockyer catchment has a legacy of land and water problems resulting from past land use and unsustainable use of underground water that has resulted in historical water sho rtages. There have also been issues with groundWATER DECEMBER 2003

27


GROUNDWATER

water salinity. There was historical base flo w in m any streams in the Valley although the dev e lopm e nt of widespread gro und water extraction effectively ended this. Concerns were identified that the irrigation of recycled water could raise groundwater levels and induce soil salinity and waterlogging and indu ce base flow stream discharge . Concerns were also held that increased salt, nitrate and phosp horu s loads co ul d impact on grou ndwater and Figure 2 . Lockyer Valley aquifer basement contours. su rface water quality. As part of an overall study streams meandered across the floo dplain examining techni cal, economic, and and "relic" levees of prior streams are still social feasibility of a proposal to bring in evidence on the alluvial plain surface. u rban wastewater fo r treatm ent and Lockyer Creek and its tributary streams irrigation in the Lockyer Valley, Bremer in the lower reaches now have a deep River-Warrill C reek Valleys and the meandering channel with a gentle levee Eastern Darling Downs, Kell ogg Brown extending to an alluvial p lain 3-6 km & Root Pty Ltd (KBR) undertook a wi d e. The sed imentary sequ ence is hydrological assessment of the Lockyer extremely variable across the study area. Valley section of the proposed project. Overview of Water Resources T his assessment required reliable evaluUse of groundwater in the alluvium of atio n o f the long-term grou ndwater the Lockyer Valley commenced in the mid water resource implications o f not 1930's from shallow wells equipped with su pplying the supplementa ry wa t er centrifugal pumps. Significant expansion of together w ith evaluati on of lo ng-term this extraction accompanied the advent of groundwater level and quality behaviour deep borehole pumps. The groundwater in a complex alluvial aquifer system. resource consists of a sand and gravel Overview of Lockyer Valley Geology aqu ife r overlain by a surface layer of fine T h e elevated h ead wate rs of th e grained clayey and silty sediments with Lockyer Vall ey along the Great Dividing individual bore yield ranging from a few Range are dominated by T erti ary age litres a second to 50 L/s. T he aquife rs in basalts extruded over a terrain of predomthe headwaters of the major tributaries are inantly Mesozoi c age sedimentary ro cks. characterised by cobbles and coarse gravel Within the study area the oldest exposed (QDPT 1994) with aquifers furt her rocks belong to the Helidon Sandstone downstream characterised by finer grained which is ove rlain by the M arburg sediments and because the individual Formation which outcrops in a belt tributary streams are isolated by bedrock extending across the central part of the highs, each aquifer acts hydraulically Lockyer Valley. This is overlain by the independently of the others except at Walloon Coal Measures. Powell et al. junctions. The surface water infrastructure (2002) provided a detailed overview of the geology of the valley and they indicated that du ring the Pleistocene period the valley floor was incised in several stages to depths of 2030 111 with depth decreasing u pstream. All u vi um was deposited by all of the streams and in adjacent fans as the va ll eys filled in th e lat e Qua t er nary p eriod. D ow n s tr e am , a l luvium overflowed from th e incised va ll ey on to th e surrounding va ll ey margins so that a wide Figure 3. Lockyer Valley thickness of surface clay. alluvial plain has developed as

in the study area includes t h ree major off-s t ream storages (Atkinson Dam, Bill Gunn Dam and La ke Clarendon), 24 recharge and regulating weirs, and 32 km of pipelines and diversion channels. In average years it has been estimated that the wei rs co ntribute approximately 6,000 ML to the groundwater storage. The aquifer yield is approximately 25,000 ML/a (QDPI 1994) how eve r wa t e r u se ha s increased until now it exceeds the yield of both the surface and underground sources.

1

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WATER DECEMBER 2003

Lockyer Assessment Approach

In essence the project involved the key steps of gatherin g, collation and analysis of relevant data for topography, land use, wa ter use, surface hydrology , soils and groundwater as well as conceptualisation of th e so il and groundwater systems. Predictive models were produced and linked to provide sin-rnlations to m ake lo ng-term (100 yea r) predictions of aquifer behaviour. The level of groundwater m odel complexity adopted was sufficient to make predictions for the purposes of feasibi lity assessm ent, but not sufficient to take the place of a formal managemen t m odel for gro undw ater allocatio n purposes. Lockyer Conceptualisation

The conceptualisation process reviewed clim ate, topography, surface hydrology, soils, geology and hydrogeology, groundwater flow systems, groundwater and surface water quality, and land and w ater use patterns . A LANDSAT image classified for vegetation types was used to divide the area into three land uses, namely cultivated land; grassland with uncleared or regrowth areas; and urban areas. However most of the alluvial plain areas have been cleared of vegetation fo r cultiva ti on . Powell et al .. (2002) provided a 7-way classification for the major landscape soil groups in th e Locky e r Va ll ey . The properties of th ese soils were reviewed and a 3-way permeability classification was derived based on textural characteristics as follows: Class 1-High permeability sandy soil s; C lass 2-Medium pem1eability light to medium clay soils; and Class 3-

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GROUNDWATER Groundwater feature continued from page 28 Low permeability medium to MODFLOW (M cDonald & N heavy clay soils (including Harbaugh, 1988); and a those with heavy subsoils). Key groundwa ter solute transport soil param eters were derived model - MT3DMS (Zheng fo r modelling using the U S and Wan g, 1999). The Sa linit y Laboratories model area covered abou t RO SET T A (Sc haap 1999) 30,000 ha and was discretised program with input of quantiwi th u ni form finitetative textural values and difference grids of250 x 250 output o f m ea n hydraulic m. Th e model grid was conductivity values. o riented north - south / east Geology was exa min ed - west and co mprised of th rough review of available 4,806 active cells. SPLASH is a one-dimensional model in drilling logs for Department of , ..:.:.., , whi ch all calculations are Natural R esources & Mines performed on a unit area basis (NR&M ) (842 bores) and Figure 4. Lockyer Valley groundwater cont ours (average with depth below ground pr ivate produ c tion bo res condition). surface bein g th e sin gle (3,33 4 ) fo ll owed b y dimension. Model simulaprodu ction of representative Lockyer Data Limit ations tions are performed on a daily time-step cross section, basement co ntour plans T he key data deficiencies that were using rain fall, pan evaporation, crop (Fi gure 2) and thickness of surface clay encountered were relative inaccura cies in coefficient and rooting depth for different plans (Figure 3). Sediment textu re was the available digital elevation model stages of crop growth, together with rules exam ined from available drilling logs and (DEM); the linuted spatial distribution of for transfer of moisture amongst th e plans indicating spa tial distri bution of groundwater o bservation bores and various m oisture stores. aquifer hydraulic conductivity, aquifer reliable private bore logs in upper tribuTh e adopted spreadsheet nutrien t porosity and aquifer textural heterogeneity taries; a paucity of available hydrauli c were prepared to support m odelling. model fo r the proj ect utilised a daily time conductivity and storage parameter data step to simulate nutrient throughput to Gro und water level contour plans were derived from analysis of pumping tests fo r soil deep drainage considering nutrient prepared for three representative periods, th e majority model area; and a lack of input from fertilisers; nutri ent input a hig h water level conditio n in February metered gro undwa ter use data outside of from eilluent; nutrient input from surface 1991, a low water level condition in the proclaimed area (central area of water irrigation ; nutrient input from Se pte mb er / Octobe r 1995 and an model). T he lack of specific crop growth groundwater irrigation; nutrient input "average" water level condition in models apart from broccoli and ceres from mineralisa tion of nutrient bearing September 2001. Figure 4 shows thi s maize imposes some limitations on the materials in soil; nutrient removal by run average condition as an exa mpl e . predictive ability of nutrient fl ux/crop off; nut rien t crop uptake; nu trient G rou nd water use was apportioned models. removal by denitrifi cation (nitrogen through division of the model into only); nutrient partition ing between soil zones and outside of the central area of Lockyer Modelling water and soil stores (phosphorus only) Th e mod e lling i n vo lv ed the the model where m etered groundwater and nutrient removal by deep drainage. production and linkage of fi ve separate use data was available, grower and Daily rainfall and mean temperature models these included: a soil / water governmental estimates of pumping rates input were required with hydrologic model - SPLASH (Arunakumaren, 1997); were compared to enable average usage parameters drawn from SPLASH o utput. spreadsheet-based crop I nutrient balance rates to be assessed. Re charge was Groundwater flow was mode!Jed with models developed in-house; an unsatuassessed through close examination of MODFLOW as a single layer model. A r ated zone mod el MODHMS r epresentative long-term groundwater number of powerful techniques were ydroGeologic, 2001); an industry (H hydrographs and recharge to the sand and employed in the preparation of the model standard groundwater flow m odel gravel aquife r at the base of the a!Ju vium including recharge estimation was found to va1y greatly. The to represe nt recharge from majority of recharge occurs surface waterbodies as well as from two sources, direct infildistributed recharge through trati on from rainfall or excess surface clayey sediments; error irrigation water through the red u c tion in th e digital o verlying clays and silts to the elevation model (DEM); and aquifer; and infiltration of non-linear regression using stream flow through the stream PEST-ASP (Doherty, 2000) in "' bed to the aqu ifer. In addition model calibration. Three types to this rainfall moves slowly of boundary conditions were through the sediment overlying used in the model, specified the aquifer over the whole flo w bounda ri es (Laidl ey valley, however the rate of C reek, Sandy Creek, T enthill movement is governed by the Cree k, M a M a Cree k , hydraulic conductivity of the Flagst one Creek, Lockyer material through which it has Creek-upstream); time-variant Figure 5. Lockyer Valley aquifer depletion risk map - "do to move. spec ified h ead boundari es nothing" scenario.

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WATER DECEMBER 2003

53


GROUNDWATER (Lockyer Creek-downstream, R edbank C reek and Moreton Vale); and no-flow boundaries fo r the o ther aquifer boundaries . The recharge processes in the model area, rainfall rec harge; irrigatio n return flow; recharge from streams; and recharge from w eirs were model l ed u s ing t h e MODFLOW r ec harg e package combining distributed and s tr ea m r ec h a r ge . D istribu te d rec harge w as modelled using MOD-HMS for vertical so il columns. T he recharge from surface waterbodies was distributed along the stream.s in each demand zone. All of the active model cells wer e d es ignat e d a s t h e MODFLOW DRAIN cells in order to m odel the surface seepage fr om t he m od el. These drain cells were placed at the natural surface, and a high drainage conductance of 100,000 m 2 / d was assigned to each drainage cell so that w ater can be removed from the model w henever water levels are above the natural surfa ce . The m o d el w as automatically calibrated using PEST-ASP (Doherty, 2000) fo r hydrauli c conductivity and su bsequently for specific yield .

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Figure 6 . Lockyer Va lley aquifer depletion risk map - scenarios 2 & 3.

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Lockyer Examination Of Scenarios

A se parate con sultancy (GHD , 2002) examined the spatial and volumetric demand by irriga tors fo r the recycled water and examined optimum irrigation scheme layouts. This work concluded that servicing of all irrigato rs who indicated Figure 8 . Lockyer Valley waterlogging ris k mapping. a demand for the recycled water would not necessa1ily be Scenario 3 - Provision of all recycled economically viable and an alternative, water demanded at $150/ML rate to areas spatially limited reticulation network served over modelled status quo; Scenario was proposed for evaluation as well as a 4 - Provision of recycled water demanded network to serve all irrigators w ho at the $150/M L price point accompanied indicated a demand. by reduction in groundwater pum ping by 50% in most areas (and 100% in Sandy Five different development scenarios Creek, Blenheim area); and Scenario 5 were exam.ined . These were: Scenario 1 Provision of recycled water demanded at - Do nothing (ie. no supply of supple$150/ML to areas w ith red uced groundmentary water to the valley); Scenario 2 water use as for Scenario 4. - Provision of all recycled water demanded by growers at the $150/M L For the simulations, 100 years of price point over modelled status quo; historical rainfall data were used and the

54

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WATER DECEMBER 2003

MODFL OW o u tp u t w as analysed to produce risk maps for aquifer depletion and waterlogging. T hese maps illustrate the freq uency o ver a 100 year period that predicted aqu ife r groundw ater levels exceed criteria set for water1o g g in g of so il s ( i e . groundwater levels r ise to above 2 m below ground surfa ce) and deple tio n of aquifer storage (ie . gro undw ater levels fall below either 2 111 or 5 m of the base of the alluvial aquifer). Vertical travel times for conservative solutes were used to examin e travel time from the surface to the aquifer to assess pathogen die- off. The very long travel times preclude the developm e n t of p a th oge n contamination of the groundwater. T h e M T3 DMS so lut e tra nsport model was used to assess concentrations of nitrate and salt in the groundwater. Because models of the crop / n utrient balance indicated that phosphorus concentratio ns would be minimal, no solute transport modelling of phosphorus was undertaken . For solute transport modelling of sal t under the scenarios where recycled water was su p plied, a si mp l i fyi n g assumption was made that there was no additional input of salt into the alluvial aquifer fro m the u nderly in g sandstones. This was rationalised in that under th ese scenarios, groundwater levels will rise to leve ls above current drought levels, thus reducing the diffe rential head between the alluvium and the un de rl ying a n d adj ace n t sandstones .

Lockyer Conclusions

T he modelli ng indicates that a "do nothing" approach will be associated with real loss of productive capacity in Lockyer Valley from over-commitment of groundwater (see Figure 5) . It is noted that currently some groundwater levels east of Gatton are at their lowest level recorded since monitoring commenced in the area in the late 1940's. Modelling of groundw ater salinity and nitrate changes using MOD FLOW and MT3DMS for the "do


GROUNDWATER

nothing" scenario was fo und to and the agricultural areas, be in1possible, because of the mainly sugar cane plantaI ,_ freq u ent dewatering of the tions, cover 77% of the , study a r ea with the m odel cells that accompanies ......... the aquifer depletion . However r emainde r cove red w ith ') the dewatering will produce a fores t scrub and natu ral <,,, pasture . situation where the head in the ,.J ~~ ... under l y ing and a dj a ce n t Because the Mackay area I sandstones will be greater t han I receives signifi can t ann ual ,, ..-' LlOCNC> that i n the alluviu m and some '-., L:.J. ~ ~ rainfall (1,665 m m/a) , much ongoi ng increase in gro undsu gar ca ne farming was 'i1 -~] """'""'....' water sa linity in the all uvium )__, r---..1 "'i;t historically on d ry la nd. fro m infl ow of saline groundH oweve r in th e late 1980's water from the sandstones is there was a rapid expansion likely. Under Scenarios 2 and in t he use of groundwater Figure 9. Mackay study area including seawater intrusion 3 the aqu ife r depl etion ri sk d rawn fr om th e alluvia l extent (i nitial scheme subsequently modified during EIS). mapping (Figu re 6) indicates sediments of the P ione er that groundwater levels will not Valley fo r the purposes of recove r and a situat ion o f supplementary irrigatio n. aquifer depletion will remain . T hi s rap id expan sion of Agai n , the darker co lours , groundwater extraction led indicate greate r risk. Under to significa nt lowering of Scenarios 4 and 5 the aq uife r grou ndwater leve ls along depletion risk m appi ng (Figure many areas of the coast in 7) indicates that groundwater the Ma c ka y area and levels will recover and aqu ifer relatively extensive intrusion dep l et i o n wi ll r e du ce. of sea water into the coastal W aterlogging risk mapping zon es of th e aquifer system loWIIIPCCA~ •w~=,,.,w_,_ fol lowed. T he coastal fringe ( Fi g u re 8) indica t es that conj un ct i ve groundwater .m.-u:.'l'::lm::: area between Sandy C reek pumping will be required to •tN:IJ"J.:r/.J:""' and Bakers C re ek to the manage groundwa ter levels south o f Mackay has been Figure 10 . Baseline waterlogging risk mapping. with gro und water pumping in particularly impacted. excess of 50'¼, of current levels so uth and west of the city of Mackay and Ma ckay City Council has fa ce d required in some key areas suc h as Lower has an area of approximate ly 720 km 2 . pressu re to reloca te its existing Mt La idley Creek . Overall m inor gro undThe Pioneer River w hich has a catchm ent Bassett WWT P for a numbe r of reaso ns water salini ty increases were projected to area of 1,489 krn 2 , flows across th e including odo ur management together occu r and projected nitralc were assessed alluvium , in a generally easterly direction with pressure to find alternatives to the to be acceptable. to the coast that it crosses at Mackay. T o disposal of e ffi uent via outfall because of

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the south o f the Pio neer River two creeks, Bakers Creek and Sandy C reek also traverse across th e allu vium. The study area is located in between these two creeks and is indica ted in Figures l & 9. The study area cove rs an area of79 km 2 ,

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Table 1. Mackay: groundwater Implications for the three conjunctive use scenarios. Frequency of impact over 50 year period ( %)

Areas with groundwater within 2 m of ground surface (ha)

Areas with groundwater below mean sea level (ie. potentia l subject to seawate r intrusion) (ha)

Scenario 1

Scenario 2

Scenario 3

Scenario 1

Scenario 2

Scenario 3

1560 .2 1347.1

1496.3 1 286.9

1 4 35.8 1226.6

1340.6 449.8

1361.6 499.1

1382.3 537.9

1100.6 955.9 836.6 722.2 604.6 4 7 3 .1

1038.8 897.3 782.6 675.1 563.5 437 .8

984.8 848.7

377.0 267 .8

346.2 24 3.4

133.1 37.3 1 2.4

126.9 36.3 12.3

5 10 20 30 40 50 60 70 75 80 85 90 95

m ission ing of the Mt Bassett plant and redirection of wastewater to an upgraded Bakers C k WWTP. Treated effluent fro m this plant would be reticu lated to irrigate sugar cane in Chelona-Hornebush areas. Up to 8,500 ML/a of irrigation will be available to irrigate 4, l 70ha (3,159 ha in Stage 1 followed by 1,010 ha in stage

736.9 633.6 529.2 403.1 319.4 225.6 1 19.6 34 .6 12.0

2) of cane produ cing land with a predicated increase in sucrose yield of 25%. T he project will also improve treatment of effluent fro m the T ho mas Bo rthwick & Sons abattoir, ensuring that it meets necessary enviro n mental li cens in g requirements and securing employm ent for 500 staff.

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An environmental impact statement is being prepared for the project EIS currently being prepared for the project, and a series of studies have been u ndertaken in support of the E IS process with a key foc us being on nu trient export to Great Barrier Reef M arine Park. Water balance modelling undertaken using MEDLI has been undertaken to proj ect overflow fr equ en cy from balancing storages. Su rface water (Sacra m ento model) modelling undertaken to project stream flows and coastal hydrodynami c modelling (D ELFT 3D) of the impacted streams and estuaries has been undertaken to determine dilution. In parallel with these studies soil / water / nutrient and groundwater modelling were undertaken to assess groundwater impact, and th is work is described in the following sections. Overview of Pioneer Valley Geology

T he Pioneer Valley aquifer co nsists of high ly channelised sand, gravel , silt and clay aquifers deposited over an undulating surface in rocks of generally Palaeozoic age. [n the MWRP area the basement generally forms a relatively gentle easterly sloping shelf with the exception of an easterly trending palaeochannel of Sandy Creek whi ch is incised back beneath the southern areas of the proposed scheme. The water beds of the aquifer in the MWRP area are generally in the order of 5 - 10 111 thick and consist of sand and gravel deposited on the basement material and overlain by less permeable and generally finer textured sediments consisting dorn.inantly of silty and sandy clay w ith layers of clay. The morphology of the individ ual aquifer water beds is complex with there being little lateral


GROUNDWATER

strat i graphic continuity evident, however the fine r grained sediments more or less are continuous as a surface layer. NR&M (Kuhanesan et al., 2002) have argued that the lack oflatera1 continuity within the layers of finer sediment types all ows the sediment pile from the su r face to the basement to behave as a single aquifer and have indicated that the behaviour of groundwater hydrographs supports th is.

model has o ne layer and uses the SPLAS H water balance model (Arunakumaren, 1997) for recharge. A telescopic mesh refinement techniqu e was used to "zootn in" on MWRP a r ea. The MODHMS model j/~ (H ydroGeologic, 2001 ) was used to simulate unsaturated zone transport times; spreadsheet-based nutrient balance models were used to predict • :::"C::c~ nitrogen and phosp horus loss to deep drainage and Figure 11. Wat erlogging risk mapping with move to 100% MT3DMS (Zheng & Wang, Overview Of Sandy recycled water. 1999) was used for solute Creek/ Bakers Creek Water transport m odelling to predict nutrient co nce ntrations in Resources groundwater. The aquifer is genera lly recharged directly by rai n fall with Mackay Examination of Scenarios natural groundwater discharge towards both Sandy Creek and Initially a 50 year sim ulation was run using the PGM without Bakers C reek that act as drains to the system. Groundwater is supple mentary irrigation (see Figure 10) and this modelling pumped from bores to provide supplementary irrigation of sugar confirmed the shallow gro undwater along the coast as well as an can e and some m inor harvesting of overland flows to earth ring additional area in the north west of the study area (see Figure ranks is also practiced. Som e recycling of effluent to irrigati on 10). A 50 year si mulation was then ru n with all groundwate r is currently practiced in the north west of the study area. The pumping replacement by recycled water (see Figure 11). T his key issue in the Bakers C reek / Sandy Creek area is the intrusion simulation indicated significantly expanded shallow groundwater of sea water from the coast into th e alluvial aqu ifers. Currently tables (see Fi gure 11 ). A series of additional simu lations were the margi n of the sea water intrusion area is located well inland with i ntrusion occ urring not onl y westward from the cast but also la t erally in from Bakers Creek and Sandy C reek.

Ii{f~

...

.::::-:==----

Mackay Assessment Approach

Initially historical groundwater level and quality data were evaluated to check for the presence of shallow groundwater levels. Not surprisin gly, to the east of th e Bruce Hi ghway, towards the coastal fringe, historically shallow groundwater levels were noted to have occurred. Approxi mately 22% of the initial subj ect area was found to be potentiall y subj ect to groundwater levels to within 2 m of the ground surface. Accordingly mode]Jj ng simulatio ns were undertaken to examine grou ndwater level behaviour for va ri ous scenarios of suppl y of recycled water and conjunctive ground water pumping. Because the key water resource manage ment issue in the area is sea water intrusion into the aquifer, groundwater elevations in areas adj acent to the coastal zone were also close ly investigated because w here groundwater elevations are drawn down below mean sea level, there is potential to draw in seawater. Following the grou ndwater level evaluati o ns, nutrient modelling was u ndertaken to examine th e likelihood of nutrient contamination of the underlying groundwater syste m. Mackay Modelling

The key aim of the modelli ng was to enable temporal and spatial changes to groundwater level and quality to be determined to identify areas at risk of groundwater waterloggi ng and salinisation as well as areas at risk of nu trient pollution. Unsaturated zone m odelling was undertaken to assess vertical travel time from the pl ant root zone to the groundwater surface for the purposes of assessing pathogen risk. A developmental version of the Depa rtment of Natural R esou rces and Mines P ionee r Groundwater Model (PGM) developed by Kuban Kuhanesan was adopted for the study. Th is MODFLOW model that was at preliini nary calibration stage was made available by DNR&M to Mackay Water to assist the E IS process. The groundwater tlow

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57


GROUNDWATER

undertaken adopting varying proportions (Scenario 1 - 75% effiuent, Scenario 2 50% effiuent, Scenario 3 - 25% effiuent) of groundwater conj unctive use in areas 500 m inland of the edge of the existing sea water intrusion margin. Again although the area at risk of seawater intrusion was greatly diminished, the shallow groundwater along the coast was confirmed as was an additional area in the north west of the study area. Table 1 summarises the implications of the three conj unctive use scenarios. The key problem encountered in this analysis was the determination of what is an acceptable frequ en cy of shallow groundwater waterlogging. Historically some established cane growing areas of Mackay have shallow groundwater level problems (eg. in the Mount Vince area some growers seasonally have to pump groundwater to waste to lower groundwater levels beneath their crops). Because the Mackay area can experience periods of prolonged monsoonal rainfall there is potential for the cyclic leaching of soils, thus the impact of periodic shallow groundwater levels may not necessarily preclude sustainable sugar cane growing. The initial supply areas for the scheme were subsequently modified to defer effiuent supply to marginal areas where shallow groundwater was considered to pose an unacceptable risk. The wacerlogging frequency contours were not coincident with property boundaries, accordingly an exclusion criteria based solely on a specific unacceptable frequency of waterlogging could not be adopted, however the areas remaining within the initial supply area had predicted waterlogging frequencies less than 50% of the time and generally less than 25% of the time. Mackay Conclusions

The key finding of the modelling exercise is that the wholesale replacement of groundwater-sou rced irrigation by recycled wastewater in the H omebushChelona area would not be a panacea for the sea water intrusion problem. Whilst providing some short-term relief, over time rising groundwater levels and soil salinity would ultimately lead to the loss of farms in marginal areas. H owever, modification of the spatial distribution of areas served to defer development on marginal lands together with maintenance of conjunctive groundwater pumping in areas well inland from the sea water intrusion margin should allow a sustainable scheme to be implemented. 58

WATER DECEMBER 2003

Although nutrient modelling was hampered by difficulties in assessing nitrogen immobilisation, because the MWRP project will entail no greater application of nitrogen than that current under the existing cane farming; because no real expansion of such farming will occur; and because nitrogen will be added in effiuent more gradually, the overall nitrate impact on the aquifer will be less than the status quo. T hat having been said, the study has indicated that a significant portion of the nutrient flu x to Sandy Creek and Bakers C reek is likely to be sourced from the base flow discharge of nitrate-impacted groundwater. Modelling indicated that phosphorus leaching was unlikely to occur.

Summary The Lockyer Valley suffers a serious overdraft of groundwater and surface water extraction over replenishment. Failure to secure a source of supplementary irrigation water for the valley will result in a major loss of productive capacity through aquifer storage failure. Predictive modelling has assessed that the provision of treated wastewater as proposed in the South East Queensland R ecycled Water Proje ct will be sustainable if managed w ith targeted conj unctive groundwater use. The Bakers Creek / Sandy C reek area of the Pioneer Valley at Mackay suffers a serious overdraft of groundwater extraction over replenishment and this situation has led to sea water intrusion into the aquifers . The proposed Mackay Water R esource Project aims to alleviate some of this water shortage through the provision of treated wastewater. Predictive modelling has assessed that the provision of treated wastewater as proposed in the MWRP will be sustainable if supply to key areas of potential shallow groundwater development is deferred until longer-term data is available to confirm its viabili ty or otherwise. Shallow groundwater levels, soil salinisation, and nutrient pollution of streams and aquifers does occur in Australian settings. Sustainable use of recycled wastewater requires planning to avoid these problems. In larger schemes the manifestation of these problems is the result of a complex interplay of factors. Cost-effective models and techniques are now available to enable reliable assessment and prediction of impacts.

Acknowledgements The permission of KBR for the authors to publish this paper is gratefully acknowledged as is the permission of the Brisbane C ity Council (BCC) and Mackay Water. BCC was not a publisher of chis subnussion and cakes no responsibility fo r its contents.

References Arunakumaren, NJ (1997) A lumped parameter model for simulating the temporal behaviour of moisture in the plant root zone and in the unsawrated zone below the root zone. LWRRDC R&D Project QP127, Resource Sciences Centre, Department of Natural Resources, Doherty J (2000) PEST - ASP. Mod e lI ndependent Parameter Estimation. Watermark Numerical Computing, Guttridge Haskins and D avey (GHD) (2002) B risbane C ity Cou n cil South Ea st Queensland R ecycled Water Project Infrastructure Costs Study - Final R eport, November. Hydrogeologic (2001) MOD-HMS, Herndon, VA 20170, USA Kuhanesan S, Murphy S. and Sorenson R (2002) Groundwater Model Conceptualisation Report for the Pioneer Valley Groundwater Eva luation and Management Project, Queensland Department o f Natural R esources and Mines, August. McDonald MC and Harbaugh A W (1988) MOD FLOW, A modular three-dimensional finite difference groundwater flow model. U.S. Geological Survey Powell B, Loi J and Christia nos N G (2002) Soils and Irrigated Land Suitability of the Lockyer Valley Alluvial Pl a in s, South-East Qu ee nsland , D epartment of Natu ral Resources and Mines, Queensland Queensland Department of Prima1y lndustries (QD PI) (1994) Overview of the Water Resources of the Lockyer Valley, J une Schaap M G, (1999) Rosetta Version 1.0, US Salinity Laboratory ARS US Department of Agriculture, Riverside, California. Zheng C and Wang PP (1999) MT3DMS: A Modular Three-Dimensional Multispecies Transport Model for Simulation of Advection, Dispersion and C h emica l R eactions of Con taminants in Groundwater Systems, Documentation and User's Guide. US Army Corp of Engineers, Contract Report, SERDP-99-1.

The Authors Peter Evans is Senior Environmental Scientist - Waste Managem ent & Groun d water, peter.evans @ halliburton.com. Jerome Arunakumaren is Senior Groundwater Modelling Engineer, jerome .a r unakumar e n @ halliburton.com, both with KBR Kellogg Brown & Root Pty Ltd, 555 Coronation Drive, Toowong Qld Australia 4066.


~

WATER

COPPER PIPE CORROSION: A WATER INDUSTRY PERSPECTIVE G Ruta Abstract Corrosion of copper water pip es has been recognised throughout the world for decades. In the small proportion of cases where accelerated or rapid cotTosion takes place, the result can be ca tastroph ic for affected property occupiers/ owners in terms of leakage and property damage, potential poisoning, lack of confidence in water quality and expensive remedial works. This paper largely foc uses on a form of copper pipe corrosion (referred to as blu e-green water) that is observed at least in eastern Australia, whereby particulate copper is released and whi ch can be occasionall y asso ciated with pinhole leaks. Instances of this corrosion are infrequent and appear to b e random throughout disttibution system s. Extensive research has been undertaken in Australia aim ed at better understanding blu egreen water and therefore developing pra ctical preventative and remedia l solutions. H owever, despite the research having provided many observations, the so lution s r e m a in e lu s i ve. The phenomenon can be summarised as follows: For some, as yet unidentified reason(s), a small proportion of copper u1ater pipes are incompatible with high quality (generally soft) drinking water and hence undergo accelerated corrosion, resulting in blue-green water.

Introduction C ity West Water is responsible for managing the water supply distribution system that provides drinking water to a population of some 600,000 domestic, co mmer c ial a nd indu s trial u se rs throughout c entral a nd we s t ern Melbourne. Approximately 60 reports are receive d per year of actual or suspected copper pipe corrosion. Copper, like all metals, is subject to corrosion. In the vast majority of cases the extent of corrosion within copp er water pip es is essentially imp er ce ptible. Howev er, in the smalJ minority of cases where accelerated or rapid corrosion cakes place, th e result can be catastrophic for This is an edited ver..ion of a paper fim presented at the AW A 20th Convention, April 2003.

affected property occupiers/ owners m terms of leakage and property damage , potential poisoning, lack of confidence in water quality and exp ensive remedial works. The race of copper co rrosio n can be considered as slow when it is spread uniformly over the internal pipe surface and equal to 4x10-5 cm/year; however a rate exceeding 4x10-4 cm /yea r is considered to be rapid (Lagos, 2001 ). Copper pipe corrosion has been described to take place in several ways, ranging from rela tively uniform surface corrosion, to form ation of pits (H olden, 1970; Edwards et al, 1994). Gen erally speaking, surface corrosion tends to be associated more with by-produ ct release causing contamination of cap water, whilst piecing is more likely to be associated with pipe failure. It can be diffi cult to accu rately determine numbers or proportions of properties in which copper pipes are un dergoing acce lerated co rro si o n. Generally estimates are m ade by water service providers from customer feedback of blue coloured water, pipe failure and staining of porcelain or tiled surfaces. Blue colour e d wate r and pip e failure und o ubtedl y ind i cate significa nt corrosion, however this is less certain with staining alone. D espite its overalJ low race of occurrence (likely to be well below 1% of prop erties) , accelerated copper pipe corrosion is widespread. For example, approximately 35% of towns in country N.S.W. reported cases of blue coloured water and/ or pitting (Land & Water Conservation, 1999) . Interestingly, a 2001 survey in Sydney resulted in 4% of respondents indicating that their tap water looks blue/ green at least sometimes (Sydney Water, 2001). An estimate of the rate of green staining of plumbing fixtures in Adelaide homes was given as 5% (M aster Plumber, 1986). Accelerated or rapid copper pipe corrosion in its various forms has been observed for decades throu ghout the world (Bremer et al, 2001; W ells, 2000). Attempts at dealing with the problem in terms of remediation and prevention have often been thwarted by lack of clear understanding of either the individual or collective roles of postulated causative factors (Land & Water Conservation,

1999), as well as by the seemingly random individual instances of accelerated corrosion (Edwards et al, 2000). Attempts at even superfi cially trying to understand the problem can be made difficult by confusing the various forms of copper co rrosion a nd havi ng to face the sometimes inconsistent nomenclature used by practitioners throughout the world. For example , Edwards et al (1994) indicate two types of corrosion, including three sub-types of pitting corrosion; Lagos (200 1) indicates seven types of corrosion , including three sub-typ es of pitting; WelJs (2000) indicates fiv e types of corrosion, including fiv e sub-types of pitting. At the sam e time, care is needed to clarify and not confuse observations/disc ussions o n particular forms of corrosion (e.g. role of elevated or low pH conditions) where these may not necessarily be relevant co the particular form of corrosion being investigated. This pap er largely focuses on a form o f copper pipe corrosion that is observed at least in eastern Australia, whereby particulate copper products are released and which can be occasionalJy associated with pinhole leaks. Instances of this corrosion (henceforth referred to as blue-green water) are infrequent and appear to be random throughout distribution systems. Extensive research has been undertaken in Australia aimed at better understanding blue-green water and th erefore developing practical preventative and remedial solutions. H owever, despite the research having provided many observations, the solutions remain elusive (Edwards et al, 2000) . Since 1996 C ity West W ater has been associated with blue-green water in term s of instances reported by customers, regulatory involvement and extensive research. The purpose of this paper is to outline our learnings from the blue-green water issue chat are relevant to the water industry, in terms of: â&#x20AC;˘ managing risks associated with instances of blue-green water; â&#x20AC;˘ highlighting observations and findings from recent research into blue-green water; â&#x20AC;˘ criti cally d iscussing genera lisations about blue-green water that are not necesWATER DECEMBER 2003

59


WATER

sarily consistently supported by objective ev id ence and therefo r e c ould be misleading; and • discussing blue-green water prevention and remediation.

Managing risks associated with blue-green water According to its operating licence, City W est Water is responsible for water supply quality "to the ou tlet o f the meter, or to the property boundary if there is no m eter" . This is probably not too dissimilar to the perceived situation througho ut the Australian water industry, and quite clearly indicates that a change in water quality within premises is not necessarily the responsibility of the water service provider. However, in 1997 governm ent regulators stated that in the case of blu egreen water, there were potential li ability issues downstream of the water meter or property bou nd ary und er the Commonwealth Trade Practices Act 1974, as well as the Victorian Goods A ct 1958 and Co11s11111er Affairs Act 1972. Th e prin c ipal concern r e lat e d to "merchan tability" and "non-disclosure" o f cha n ged wate r quali t y, alb ei t downstrea m o f the m eter/ prop erty boundary . P ote n tial ri sks to wa t er se rvic e providers arising fro m. blu e-green water were identified in terms of legal actio n (reg ulatory, civil), finan cial liabili ty and adverse publicity (Ruta and Sm.ith, 2000) . City West Water's risk management strategies are based on: • obtaining specialised legal ad vice, • main tainin g tec hnical awareness of copper pipe corrosio n, • actively contributing to research, • cooperating with regulators, • regularly informing custom ers (potential health risks, research progress), • providing customers with spec ialised counselling and advice on recognising and dealing with blue-green water, including on-site water quality testing and tap £lushing strategies.

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Influence of water pH

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In a study of the quality of water emerging from over 500 domestic kitchen taps, R uta (2003) found an inverse relation between pH and copper levels in both hot and cold water.

As a result of past largely anecdotal and limited observations, suggestions were made that eleva ted water pH could be a key causative facto r for blue-green water corrosion (Wells, 1998). This led to advice that a pH less tha n 8.2 is optimum for avoiding such corrosio n (Taylor, 1995 ; Land & Water Co nservation, 1999) . H owever, the Stage 1 research clearly showed, usin g controlled observa tions in both the laboratory and at fie ld sites, that blue-green water corrosion could take place between pH 7 and less than 8.2. The Stage 1 research also indicated that release of corrosio n products was effectively inhibited at pH 10 . However, subsequent Stage 2 observations showed that signifi can t copper release eventually could take place after about 7 months at pH 10 (Figure 1).

Variation between batches of copper tubes

Both the Stage 1 and Stage 2 research showed va riabili ty in corrosion product release betwee n different types and batches of Australian manufactured copper tubing (Figure 1). This included ben dable, annealed and hard-drawn tubes. T he Stage 1 wo rk concl u ded that hard-drawn tu b ing is essentially resistant to corrosion in terms of co rrosion produ ct release. H owever, Stage 2 showed that after approximately 15 months of exposure a batch of hard-drawn tube co mmenced significant produ ct release.

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Since 1997 C ity West Water has worked closely with the CSIRO on applied research aimed at better understanding blue-green w ater, including overcoming or preventing occ urrences. The work was und ertaken in two stages, each resulting in its own research repo rt: Stage 1 (Taylor et al, 1998) an d Stage 2 (Taylor et al, 2001 ), summarised in Wa rer (H alloran et al, 2002).

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60

WATER DECEMBER 2003

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Influence of chlorine / chloramine

Stage I research confirm ed other reports (W ells, 2000) that presence of a small amount (0.2 mg/ L) of free chlorine or m onochlo ramine had th e beneficial effect of seve rely limiting corrosio n produ ct release from initially new copper tubing (Figure 2). H o wever, despite this p ro tec tive effect, the Stage 2 research noted t hat it was not necessarily reflected in a consistent absence o f underlying tube surface corrosio n. For example, Fi gure 3 shows m arked signs of corrosion o f Batch C tubing despite it having displayed little sign o f copper release (Figure 2). Su ch observations of -apparent in consistency between corrosion product release and underlying surface corrosion could indicat e that these are separate processes. For example , it may w ell be tha t ch lorine/ chloramine mi tigates against corrosion product release without necessarily preventin g underlying corrosion. Wells (2000) refers to the benefic ial role of ch lorine with respect to corrosio n produc t release, but also notes the possibility of it causing u ndesirable on-going

Batch:

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or even accel erated underlying corrosion. T he Stage 2 research also fou nd that: • introduction of chlorine to already corroding tubes had the effect of redu cing th e degree of copper product release although not necessarily to consistentl y acceptable levels (i.e . less tha n 2 rng/L); and • initial exposu re of tubes to chlorinated water for 18 months, fo llowed by removal of ch lo rine, preven ted initia ti o n of

sustained , sign ifica n t copper release over a subsequ ent 6 m onth period, although temporary outbreaks of copper release over 2 m g/L occu rred.

Influence of hot water A strong trend that has emerged fro m reports of blue-green water is that essentially all instances are associated with co ld water copper pi pes. T his is supported by fi ndings of a study in which copper levels

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61


WATER

Table 1. Blue-green water "facts"/folklore and comments. Blue-green water (BGW) "facts" / folklore

Comments

BGW may occur if water quality is outside the range of drinking water guidelines.

Yes, but also may occur when water quality is with in the range of drinking water guidelines. * #

BGW is an elevated pH issue.

No. BGW can occur from pH 7. *

BGW caused by poor installation practices.

No empirical evidence. BGW initiated in laboratory trials with simple copper tubes. *

BGW occurs in long lengths of pipe.

Yes, but also occurs in short (-1m) lengths. *

BGW occurs in dead-legs.

Yes, but also occurs in non-dead-legs. *

BGW caused by tube bends and fabricated j oints.

Yes, but also occurs where there are no bends or fabricated joints. *

BGW associated with infrequently used taps.

Yes, but also occurs with taps used on a daily basis.# The appearance of BGW corrosion product at infrequently used taps may simply reflect accumulation rather than accelerated corrosion.

BGW occurs in the extremities of water supply distribution systems. Yes, but also occurs in non-extremities.# BGW caused by a lack of chlorine in the water supply.

A lack of chlorine in itself is not the cause , as BGW is not reported in a majority of properties where chlori ne residuals are low.#

Additional chlorination of water supplies will eliminate BGW.

Perhaps. But it may not necessarily address underlying surface corrosion . The key lies with determining why most properties do not develop BGW despite low or absent chlorine residua ls.

BGW caused by MIC.

MIC may be t he mechanism/ process by which BGW takes place but it is unlikely to be the triggering or predisposing cause. If it were, BGW wou ld occur more frequently.#

BGW / copper corrosion is a recent phenomenon.

Problems with corroding copper pipes have been occurring internationally for decades (Holden , 1970).

BGW occurs in very isolated instances.

Instances of BGW are widespread in many areas.# Copper pipe corrosion occurs world-wide .

* refer Taylor et al (1998) and/or Taylor et al (2001).

# City West Water observations.

were monitored in water em erging from over 500 domestic kitchen taps between 1998 and 2000 (Ruta, 2003). In that study it was fo und that: • copp er levels are generally higher in water fro m the cold tap as compared with water from the hot tap; • extrem e (high) copper levels are much more likely to o cc ur in water from the cold tap as compared with water from the hot tap; • most of the copper in water emerging from hot water taps originates either upstream of, or w ithin hot water systems, but no t fron1 the downstream ho t water pipes. MIC involvement in blue-green water

Strong evidence for the possible role o f mi crobial influenced corrosion (M lC) in blue-green water has been described in recent Australian work (O'Halloran et al, 2001, 2002). This also refers to the possible role of M IC in corrosion product release itself, rather than necessarily in the possibly separate pro cess of underlying COlTOSJOn.

Generalisations concerning bluegreen water: beware D espite significant investigations and research, th ere is currently still a lac k of adequate u nd erstandi ng of th e two most

62

WATER DECEMBER 2003

critical issues con cerning blu e-green water. T hese being: • the specific tri gger or ca use(s) fo r initiation o f the corrosion process; and • treatment(s) for prevention and remediation. N evertheless, much info rmatio n has been gathered about the issue, over which there is general agreem ent. For example, th e protective role of hot water and chlo rine , the irrelevan ce of flu oride and electrical currents, and th e seem ing random ness and unpredic tability o f instances of blue-green water (WSAA , 2002). O n the other h and, there are a number of seemingly selective generalisations or "facts" that continue to be propagated on blue- green water that are either largely unsubstantiated by empirical evidence or in fact in many cases actually contradicted by such evidence. Examples of some of these are referred to in Brem er et al (2001 ). The result is that this "folkl ore" becomes accepted as correc t, and unfortunately serves to (a) divert from and camouflage known facts about copper pipe corrosion, (b) cause misinform.ation and frustration amongst plumbers, affected property occupiers, water service providers and (c) potentially lead to wasteful and fruitless preventative or remedial measures.

Table 1 lists some of these " facts" together w ith comments on their dubio us (or lack credibility. At times even we ll intentioned, systematic research can also lead to misinfo rmation . For example, and as discussed above, initial C SIRO conclu sio ns concerning apparent non-initiation o f blue-green water at p H 10, and corrosion resistance of hard-drawn tubing w er e subse qu ently r ec onsidered by extended periods of observation (Taylor et al, 2001) . As a result, caution must be exercised in making premature generalisations on blue-green water and potential remedies. A case in point lies with consideration o f chlorination as remedial strategy fo r controlli ng corrosion product release, withou t being certain of its role in attenu atin g o r po ssibly eve n enhancing underlying corrosion.

on

Blue-green water prevention and remediation C urrently there are no certain m eans available for preventing blue- green w ater corrosion in copper pip es. As a result, the only way to prevent the possibility of this problem is to use ano ther pip e material. As a comprom.ise, it may be worth considering plumbing hot water pipes in copper and cold water pipes in an alternative material.


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Some work has been undertaken on rem edial treatments (W ells, 2000) but these are oflimited practical use. A major Austral ian research progra m aimed at deve loping a rem edia l trea tm ent 1s currently in progress (WSAA , 2002).

Conclusions Blu e-g re e n wat e r co pp e r p ipe corrosion is a complex phenomenon that, despite significant research, is as yet poorly understood in terms of identifyin g not only the cause(s) but also preventative and rem ed ial strategies. The phenomenon can be su n,marised as follows: Fo r s0111e, as yet 1111ide11t!fied reaso11 (s) , a s111nll proportio11 of copper water pipes are i11co111patible 111it/1 !tig!t quality (grnemlly soft) drinking water and hence 1111dergo accelemted corrosio11, resulting i11 b/11e-greeu water. Instances of blue-green water prese nt potentially serious risk to th e water service providers. T hese ri sks shou ld be recognised and carefully m anaged. R ecent research has provided greater insights into blue-green water, however it has not yet explained why a small min o rity of pro perti es d evelop th e problem wh ilst most do not. Unfortunately there are dubious generalisat i ons b ei ng propagated about blue-green water corrosion that hinder s tak e h olders' und ersta n ding a nd manage ment of the issue. Even emerging resea rc h findi ngs should be treated w ith ca ution . C u rrently the on ly certain way of preve n ting cop per pipe blue-green water corrosi on is to use alternative pipe materi als. Remed iation for existing instances is curren tly being researched.

Acknowledgement Th e author thanks City W est W ater fo r providing the resources for preparation of this paper.

References Bremer P J, Webster B J. and W ells D . (2001) Bioc on-osion of C opper in Potable Water. J ournal A111ericn11 Water Works A ssocia1io11, Aug ust 2001. Edwards M , Ferguson) Fand Reiber S H (1994) The Pitting Corrosion of Copper. J o11mal America/I W ater Works Associatio11, July 1994. Edwards M , Jacobs Sand Taylor RJ (2000) T he Blu e Water Phenomenon. j o,mrnl A 111erica11 Water Works Associatio11, July 2000. H o lde n W S (1970) W ater T reat111C11/ a11d Ex ami11atio11. J & A Churchill, London. Lagos G (2001) Corrosio11 <if Copper Plu111bi11g Tubes mrd the R elease of Copper By-Prod11cts i11 D ri11ki11g Water. Inte rn at iona l Coppe r Association Ltd , N ew York. Land & Water Conservation (1999) Copper Corrosio11 i11 Co1111try N.S. W.: Survey a11d

Ma11age111c11t Strategies. (N ew South Wales) Department of Land and Water Conservation, Urba n Water Cycle Plann111 g Unit , Septem ber 1999. Maste r Plumber ( 1986) Cree11 S1ai11s 011 Sm1itary111are a11d Tiled S11!faces. The Master Plumber of S.A. , February 1986. O' Halloran R , Smith F, Taylor R. and Goodman N . (2001) Blue Water Corrosion of Copper: Causes and Implications fo r R.emedial Treatment. Corrosio11 a11rl Pre11e11tio11 200 I. Proceedings, Australasian Corrosion Association Inc. Newcascle, N ew South Wales Australia, 19-21 November 2001. O'Halloran R , Taylor R , Smith F, Go odman N , C ritchley m (2002) Beating the l31uesR esearch into Blue Wa ter in Copper Plumbing. Water 29, 7 p 37-40. Ruta G and Smith X. (2000) Providing Quality D1inking Water: A R.isk Analysis. E1111iro 2000 - WaterTec/1 Cc)l/fereuce, April 2000, Sydney Australia. Ruta G.(2003) H ow Your H oc Water Service Affects Water Quality. Oz11mrer. Australian Water Association 20th Conventi on, Perth. Sydn ey Water (200 1) Co1111111111iry Views 011 Dri11ki11g Wa1er Q1wli1y. Syd ney W ater internal research repo rt, J uly 2001. Taylor R J ( I 995) Blue Water in Jessica Place, De la hey. CS I R O Consultan cy R e port C MST 95-32. T aylor R. J , O' H allo ran R J , Sexton B A and Smith F. ( 1998) B lu e-green wa te r: Investigations undertaken by CSIRO for C ity

West Water, Stage 1 Report. CSIRO Consultancy R eport C MST-C-C-98-21. Taylor R J, O' H alloran R J , Smith F L, Goodman N . and Jaeger H. (2001) Bluegreen water: Investigations undertaken by CSIRO for City West Water, Stage 2 R esearch R epo rt. CS I R O Consultancy R eport CMST-C-C-2000-42. Wells D B (1998) R eview of Copper Corrosion in Potable W ater. Materials Peifor111a11ce Tec/1110/ogies, New Zealand, Report No. 78795.0 1. Wells D B (2000) R eview of R em edial T reatments for Copper C orrosion ByProduct R elease (Blue Water), Pitting and C uprosolvency. W ater Services Association of Austra lia, Research R epo rt N o . 205. WSAA (2002) Corrosion of Copper Pipe in Australian Drinking Waters. Water Services Asso ciation of Australia, Materials Fact Sheet No . 5.

The Author Georges Ruta is Water Quality Scientist with City W est W ater Limited, one of Melbourne's service providers.. He has worked closely with both WSAA and CS IRO in the planning and review ing of copper corrosion resea rch in Australia. Locked Bag 350, Suns hine, Victoria 3020, grnta@citywestwater.com.a u

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LOOKING TO THE PAST Ed. Two readers have submitted notes on Aboriginal water resources, which are somewhat relevant to Dingle Smith's comments in Aq11aphemera, September.

NATIVE WELLS H Bandier Within their nomadic existence in the o utback th e Au stral ian Aborigines possessed great logistic skills , in making use of their varied environment. Most important was the availability of fresh water and special structures were built to harness and protect potable water in desert country. (Also aquaculture in the shape of fish and eel traps in streams was a 1najor source of diet for some tribes) . (Bandier H, 1999). Native wells occur all over Australia. They were sunk in soil or sand and usually contained a meagre supply. They vary in depth from half a metre to about six metres. The bottom was often enlarged to give greater capacity. Some wells were sunk with a slight curve or serpentine down-course, th us shield ing the water from the direct rays of the sun , or provided with covers to minimise evaporation and preserve water cleanliness. They are frequently hidden under a bush or in the midst of a thicket, and can easily be missed Sometime after Australia became a colony, exploration of the interior began, and native wells were often essential to their progress. An important early explorer was the German scientist Dr Ludwig Leichardt, w ho in 1844-5 covered about 5000 km from Morton Bay (B risbane) to Port Essington (near Darwin). Two Aborigines in his party enabled him to find numerous native wells. In 1886 the Licensed Surveyor D avid Lindsay (Lindsay, 1886) set out from Dalhousie Station in South Australia to near the Queensland border. H e covered "a distance of 430 miles and fixed the position of nine new wells" . The wells were centres for the Wangkanguru people, who later had to abandon them. In 1983 a group from th e Australian National University visited the wells, following Lindsay's report. They are described in detail in an academic paper (H ercus & Clarke 1986).

size w hich may contain several kilolitres almost permanently. They have been used throughout prehistory and their use can be dated from artefacts encountered in the vicinity. They were often protected from evaporation or fouling by animals. A good example is at Hunters Hill in Sydney. In a small public reserve named Kelly's Bush, about 30 m from shore, is a fairly large rock platform, about 11 m across and 5 111 wide. In the centre is a rock pool, approximately 3 m long and 1.3 m deep . As there are no fresh water streams in the whole of this peninsula this rock pool must have been most important, particularly for families gathering she!Jfish.

BAIAME'S WATERWORKS IA E Bayly A small isolated granite outcrop at Byrock, north western New South Wales, contains a rock-hole which, according to Aboriginal mythology, w as excavated by the C reato r , B ai arne, d uring the Dreamtime. A dead straight section of the Mitchell Highway between Bourke and Nyngan runs through the little township of Byrock. Most travellers press on oblivious

to the fac t that a deviation of only 500 metres to the west of the highway would take them to a pleasant walk to some historic rock-holes on an isolated granite outcrop. These rock-holes were of great significance to a grou p of Aboriginal people w ho called themselves and the ir language Ngiyamp aa (or Ngemba). H orto n (1994) ass igns Ngiyampaa speakers to two regional groups: the Wailwan and the Wongaibon. T he core of the home- land of the Ngiyampaa lay between the Crowl and Willandra creeks to the south-west of Cobar in western New South Wales (Donaldson 1984, fig.1). People living in the stone country to the north of this region were ca lled Karulki yalu (stone country people). These p eople inhabited essentially dry country lacking permanent wa t ercourses. Another name for indigenous people living in the northern region around the Gunderbooka Range was Gunda-A h-M.yro which means "people who stay out back and don't visit rivers". For the Karulkiyalu or Gunda-AhM yro, rock basins instead of rivers were an important source of water. The supreme C reator and ancestral hero of the Ngiyampaa was Baiame (pronounced bi-army), and it was on the grani te outcrop at Byrock t hat he

Rock Pools T hese are depressions or holes in rock surfaces which hold water from the infrequent ra infall for a limited time. They range from only a few li tres to almost cave 64

WATER DECEMBER 2003

Figure 1. This water-filled rock-ho le, Wuggarbuggarnea, was , accord ing to a legend of the Ngiyampaa people, created in the Dreamtime by Baiame. Three cracks in the bedrock radiate out from this rock-hole: two minor ones in the foreground and a major one from the opposite side of the pool. Photo: Ian Bayly.


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excavated with his to mahaw k (wugga r), the ro ck- ho le known to the local Abor i g i n es as Wu gga r b u gga rn ea (Ma th ews 1904) (Fig. 1). W hen his wuggar became blunt w hile digging th e ho le, he sharpened it o n th e hard granite su rface. Gro o ves worn by the sharpe n ing of stone hatchets occur at seve ral places on th e rock surfac e. Baiame made Wugga rbuggarnea and the surro unding rocky outcrop, known to Aborigines as Bai (Tindale 1974, p . 106), his ho m e. Baiame's rock- hole is connected w ith a long straight gutter in the rock ( Fig. 2) whic h vari es in width from a metre to ha lf a metre and ru ns abo ut 50 metres across th e outcrop. This was produced by Baiam e dragging his fire wo od and larger ga me, but it served th e purpose of chann e llin g sto rm water into the rockhole w here it remained fo r a co nsiderable time . T he availability o f water made Wugga rbugga rnea a great campi ng place for the Ngi ya mpaa long before this part of the country became occ upied by E uropean se ttlers. Other water sources were t h e Mulga and Yanda C ree ks bu t th ese w e r e ra t h e r e p h e m e r a l ; W ugga rbuggarnea and the rock ponds at Gund e rbooka and Wuttagoo na were more reliable. Apa rt fro m Baiam e's waterw orks, there are several other interesting features surrounding Wuggarbuggarn ea. T here are several rust- colo ured stains on the rock w hich have been interpreted by the N giya m.paa as a legacy o f items that belonged to Baiame (Math ews 1904) . Thus w e are able to see a bull roarer, a fighting club, a boomerang and one of his spears. T here are also depressions in the rock where Baiame is beli eved to have ground grass- seed and pounded nuts to make cakes. The small granite outcrop at Byrock is somewhat of a geological curiosity in th e sense of its isolation. M ost granite in New South Wales occurs in the Eastern U plan d s in, or reasonably close to , the Gr ea t D ivi din g Rang e . G e n erally speak ing, th e Int erior Lowlan ds of Australia, including the western plains of N ew South W ales, are devoid of grani tes. The ne arest substantial outcrop of granite to that at Byrock is some 170 kilometres to the so uth in the region of the Tarran H ills (th ere is a small amount of granite at The T hree Sisters just over 20km w estnorth - w es t of B y ro c k ) . For hi s waterworks, Baiame made the most of a materi al that is globally abundant but locally very scarce.

Figure 2. A view towards the rock-hole, Wuggarbuggarnea , along the gutter which was worn by Baiame dragging his food animals and firewood during the Dreamtime. Photo: Ian Bayly

Ed. A recent note published in Water (Bayly, 2002) discusses the damage done by explorers and drovers to these very limited s11pplies, which were essential to the livelih ood of the local tribes.

The Authors Hans Bandier is an H o n ora ry R es e arc h A ssociate at M ac q u ar i e U niversity, and in his retirement has maintain ed an interest in aboriginal use of w ater both for drinking and for food production (as in fis h and eel traps). Dr Ian Bayly is an H onorary R esearch Associate of the School of Biological Sciences, Monash U n iversity, and is a former President of the Australian Society fo r Lim no lo gy. Private address: 50 1 Killiecrankie R oad, Flinders Island, T as . 7255. Email: iaebayly@ bigpond.co m .

References Bandier, H . (1999) Exploiting Maritime Food R esources. .. in pre-Euro pean Australia. Australian Institute of Marine Archeology Ann ual C onfere nce, Sydney. Bayly, I A E. (2002) Australia's Early W ater W ars. Water 29. 39-42 D o naldson, T. (1984) W hat's in a nam e? An etymological view of land, language and social identification from central w estern N ew South Wales. A borig inal History 8, 21-44. H ercus, L and Clarke, 0 . (1986) Nine Simpson D esert Wells A rcheology i11 Oceania 21 , 51-62 H orton, D . (Ed.) (1994) The E11cyclopaedia of A boriginal Australia. Abo riginal Studies Press, Canberra. Lindsay, D. (1886) Report ofj oum ey... Submitted to the M inister o f Education, Adelaide. Mathews, R. H. (1 904) Ethnological notes on the abo riginal tribes of New South W ales and Victoria. ). Proc. R oy. Soc .N .S. W. 38 , 203381.

Tindale, N . B. (1974) A borigi11al Tribes of A1.1stralia. ANU Press, C anberra.

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WATER QUALITY MONITORING: AN OVERVIEW P Maiden, D Bryant, A Gibson This article aims to provide information for engineers who are not experts in water quality m onitoring to improve their understanding of water quality and raise awareness of the different tools that currently exist, including combinations of bi ologica l t es t s, chemica l testi n g, ecological risk assessmen ts and field monitoring. Environ m ental wa t e r q uality monitoring in Australia is a multi- million dollar industry, driving a substantial portion of the overall environmental im.provement programmes across th e whole country. Fo r exam p le, in the wastewa te r treatment industry alone, decisions that have been made in the past 20 years based o n water q uality data include: • the requirement fo r nutrient removal or eillu en t reuse in inland wastewater treatment; • the req u irement for ni trification in coastal wastewater treatm en t plan ts; and • stricter contro ls on trad e waste customers to prevent heavy metals and oth er con tam.inants entering waterw ays. T he upgrades associated with these decisions have cost the Australian water user billions of dollars (and provided the Australian engineering consulting and construction industty with a large po rtion of recent profits!). The same water qua li ty m on itoring that cause d th e up grades has also validated that the overall water quality has improved, certainly on a simplistic chemical concentration basis. H owever, there is still a need fo r better assessment, management and communication of eco logical risks in o ur water resources. T his is essential to underpin the m o re sus tain able use o f ou r water resources that are sought by government, environ m e ntal and public heat h regulators, the water industry and the co mmunity . Hist orically e n vironme nta l water quality has been mon itored using mostly chemical criteria only. This approach is being stea dily superseded by one that combines ch em ical testing, biologica l testing and field m onitoring of biological 66

WATER DECEMBER 2 00 3

Water quality monitoring provides a snapshot of ecosystem conditions - regular monitoring is required for adequate assessment of environmental risk.

and chemical parameters. In this more sophisti cated approach th e ph il osophy is to understand levels of risk, and manage the factors causing risks, rather than rely solely on compliance with published values of chemical concentrations. T here is a wealth o f Australian experience which can be drawn on to illustrate options for making the best use of such tools fo r the better assessment, m anagem ent and co mmuni cation o f ecological risks in our water resources . This is relevant to all those who are involved in the assessm ent, management and comm.unication of ecological risks in our water reso urces, from suc h activities as: • reuse of treated efflu ent; • discharge of waste waters or efflu ents to receiving water bodies; • use of surface water for water supply purposes; and • aq uifer storage and rec harge using treated waste waters.

Who cares what is in the water? Australia's water reso urces are divided in to numerous m anage m e nt areas (Environment A u s t r al ia , 200 1 ) including: • 12 surface water drainage divisions; • 246 surface water river basins; • 325 surface wa ter managem ent areas; • 69 grou ndwater provinces; and • 538 groundwater management units. There is a w ide ra nge of stakeholders that has a very rea l concern and need to know abo ut the water quality of these nu merous water resources. The division of responsibility varies between states, but in Victoria, the stakeholders include: • the environmental regulatory authority (EP A Victoria); • catchment managers; • hea lth authorities (Department of Human Services); • land managers (Department of Human Services);


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• water authori ties (including urban and rural water authoriti es responsible for providing drinking and irrigation water). T h e environmental regulatory authority is typically responsible fo r discharge licences co waterways, neighbourhood environmental improvement plans, and producing policy and regul ations relati ng co water authorities and industry. Catchment managers (such as the Catchment Water Management B oards in South A u stralia or Catchment Managem ent Authorities in Victoria) typically care about m any aspect s of water quality, and are interested in snapshots of the water quality, targeted assessment of stream rehabilitation actions, cost benefi t analysis, and long term strategies fo r managing regiona l water quality. Oth er reasons co care about water quality include moni toring drin k i ng water quality, irriga tion water quality, hea lth considerations, and o ngoing land management.

Why care? Water quality monitoring is usuall y intended to answer one or mo re of the followi ng questio ns: • are we ca using an hnpact? T he answers to this question will drive • are we satisfying our regulatory/ legislative objectives? (eg. th e State Environment Protection Policies in V ictoria) T he answers to th is question can stimul ate deeper consideration of the appropriateness of the obj ectives, poss ible solutions, and perha p s fines or deeper co nsequences; • what is the background environmental con dition of the waterways? Th e answers to this question will drive • will we benefit from an enhanced environmental condition of the waterways? • are our strategic investments and decisions making a difference to the waterway quality? T he answers to this question will drive future actions, including pol icy decisions, engin eering works, and revised environmental objectives. Fro m a cynical po in t of view, a lot of water quali ty manage me nt is undertaken " beca use we have co."

What approach should we take? The traditi onal approach to water quality monitoring is a rigorous scientifi c approac h. Th is is a resea rch based approach, with a case-by-case progra m me developm en t. There is a strong emp hasis on: • statistics, including rigorous experiment and pilot study design including power analysis and repli cates; • biotaxonomy, wh ich involves considerable field and laborato1y expertise, time and cost; and • biological response assessm ent, which involves assessment of the co mplex ecology of aquatic organ isms in their biotic and ab iotic en virons . T his is a thorough approach that shoul d produce valid resu lts in almost all cases. A m ore recen tly developed approach is rapid assessme nt of environmental condition . This approac h , initially developed in the United States, has been adopted by m any Australian states following rigorous comparison and validation of tech ni ques . In Victoria, rapid assessment of environmental condition has been incorporated as a standard protocol in the State En vironmen t Protection Policies. T h ese methods include evaluation of biological, nutrients and other water quality parameters to assess water quali ty. The methods are suitable for cost effective entry-level examination

of water quality, and produce standardised results that are comparable between studies. However, rapid assessment m ethods are often not sensitive enough for all systems, or to answer all questions, especially for large river systems or wetland systems . The m ost recent approach formally adopted by th e Victorian EPA is a risk assessment based approach, w hi ch can use a combination of the traditional and rapid approaches. A typical approach would use rapid techniques co identify areas of high 1i sk for subsequent assessment usin g m ore rigorous research- based me thods. This approach shou ld be the m ost cost effective approach, and but it will not pro vide a set of base lin e water quality data that is com parable across catchme nts.

What tools are available? There are numerous tools available to water qua li ty practitioners in Australia. This section is designed to give an overview of the cools for non-prac titioners to pro vide a basic level of understanding. Th e selection of m on itoring tools will depend on a number of fund amenta l qu estions, including: • what is to be m easured? • how quickly are resul ts requ ired? • what resources (fin ancial and other) are available:> • what are th e characteristics of the area to be monitored (i ncluding accessibili ty, seaso nal flows, etc)' In m any circumstances, th e ultim ate aim of the m o nitorin g is to dete rmine the effects o f the water quality on the biology o f th e area. The use of non-biological indi cators for estimating

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hundreds of NAT A-accredited water quality laboratories across Australia. The Australian Water Quali ty Guidelines and state-based environment protection policies provide objectives that can be used to assess water quality at a simplistic level w ithout detailed scientific knowledge. These objectives are typically based on percentile values, requiring m ultiple sampling sessions for statistical validity. C hemical analysis is natu rally a preferred tool when examining specific pollutants, such as discharge of nitrogen to Port Phillip Bay, or aluminium to inland rivers. Algae Macroinvertebrates are the cornerstone of freshwater biological monitoring throughout Australia.

the condition of a biological quality element may complement the use of biological indicators but it cannot replace it (EU, 2003). As non-biological indicators may be needed to validate data and interlink with other monitoring progranunes (eg. treatment plant discharges) it may be necessary to combine both indicators and provide some method of linking the two (eg. linking a biological response to certain chemicals o r water quality conditions) . Chemical Parameters

Basic chemical parameters fo rm the fo undation of the vast maj ority of water quality monitori ng progra mmes as they are a quick, cheap and simple to ol. Water and sediment samples can be tested for inorganic and organic chemical parameters at

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WATER DECEMBER 2003

Algal blooms typically occur in hot, still water bodies where there are adequate nutrients. Hence total algae counts are a highly sensitive indicator of eutrophication of water sources, especially during summer seasons. Blue green algae are the most famous example of toxic algae, monitored weekly by numerous water and catchment management authorities throughout the summer months. T he large toxic blue-green algae scares in the 1980's and 90s are good examples of water quality monitoring gaining public attention. These scares are often held responsible for much of the current interest in rehabilitating Australia's largest river systems. Diatoms

Diatoms (pro noun ced dye- ah-toms not dye-atoms!) are unicellular algae that live in aquatic habitats attached to sediments, snags, rocks, etc . Diatoms are simple, well studied organisms that have known tolerances for electrical conductivity and nu trients. Due to their lack of mobility, they provide a fixed point monitor of water quality history. H ence these diatoms are ideal fo r 1nonitoring sh orter term biological impacts, and are useful for monitoring the start and finish of discharge periods. Diatom monitoring is often used as a complement to macroinvertebrate and chemical monitoring. For example, diatoms are believed to be the most sensitive monitoring tool in the lower Goulburn R iver. H ence Goulburn Valley Water has used th is suite of indicators as part of their EPA licence, and also to assess the performance of the new tertiary w astewater treatment in Shepparto n. M acroi nvertebrates

M acroinvertebrates (bugs) are used worldw ide as a highly sensitive biological indicator. Macroinvertebrate monitoring is frequently mandated by EPA Victoria, with macroinvertebrate parameters included i n regiona l SE PP obj ect ives. Macroinvertebrates provide a record of water quality over their lifetime and so are used to monitor longer term impacts than diatoms . There are many established protocols fo r assessing macroinvertebrate data. SIGNAL (Stream Invertebrate Grade Number - Average Level) is a simple scoring system for macroinvertebrate samples from Australian rivers. This protocol focuses on water quality impacts on macroinvertebrate communities. AUSRIVAS (Australian River Assessment System) is a set of mathematical models that can be tailor-made for different aquatic habitats and d iffe rent seasonal conditions. T hese models predict the aquatic macroinvertebrate fauna expected to occur at a site in the absence of environmental stress, such as p ollution or habitat degradation . T his protocol foc uses on habitat quality and stream condition.


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simon Engineering

Diversity and abundance assessment are designed for local conditions and used to assess broader ecological condition. O ther uses for macroinvertebrate monitoring can includ e: â&#x20AC;˘ wetland condition assessment (using sweep sampling); â&#x20AC;˘ lake biomass calcu lation (based on grab samples); an d â&#x20AC;˘ heal ch risk assessm ent based on m osquito mon itoring. Ma croinvertebrate collec tion, sorting, counting and data analysis needs to be done by expert practitioners even at a basic level. The Victorian EPA and Department of Sustainab ility and E n vironment conduct statewide river health monitoring using m acroinvertebrates as the central indicator of stream ecology . Fish Fish mon itoring is one of the more broadly accepted forms of monitoring in the comm un ity, because it represents a tangible o utcome that non-tech nical people can understand. H owever, it has more limitations from a scie ntifi c point of view, as fish are highly mobile so they can often avoid suboptimal co nditions. Monitoring requires much m ore rigorous knowledge of migratoty patterns and is subject to more variable seasonal and other effects. However, it is very useful for m o n itoring and assessing enviro n mental flows, overall environmental inventories, and catchm.ent environmental values. T he Patawolonga Catchment Wate r Management Board and Murru mbidgee Catch m ent M anagem ent Boards are cu rrently using fish monitoring of wetlands and rivers to determin e the sustainability of c urrent management practices on fish popu lations. Other Biology

Other popu lar biological monitoring tools are frogs, platypuses, and vegetation. The high social profile of these organisms le nd th emse lves to th e newly developing co mmuni ty mo ni toring programmes, such as chose used by a number of water authorities. Beyond providing raw scientific da ta, these commu nity monitoring programmes also provide valuable educational cools for scude nts and th e broader co mmunity about the biological and ecological value of natural waterways. Th e City of Maribyrnong has included frog monitoring in the Stony Creek Neighbourhood Environm ental Improvement Plan to provide soc ially relevant en vironmenta l in format ion to the ir local co mmuniti es.

Where can I find out more? This article is only intended to be a brief overview of water quality monitoring from a practitio ner's poi nt of view. For m o re details on procedures, protocols, and case studies we suggest the Victorian EPA website.

References Enviro nment Australia, " Face Sheet 23 - Water Quality in Aust ralia Key Findings" , http: / /audit.ea.gov.au/ AN RA / docs/fast_facts/ fast_facts_23. h m1I. European Union, Water Framework Directive, Guidance on Monitoring for the Water Framework Direc tive, January 2003.

The Authors Patrick Malden (pmaiden@wsl. com.au) and David Bryant are biologists in the aquatic ecology department at W SL w ho sp end a lot of their time design ing, implem e nting, and analysi ng water quality monitoring programs for engineers. Antony Gibson is an engineer, all ac W SL Consultants Pty Ltd, 2-8 Harvey Street, R ichmond 3121.


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RECLAIMED WATER: MANAGING THE LEGAL RISKS L Moore Summary Many water suppliers recognise the need to have appropriate risk management plans and strategies in place to deal w ith the new risks to their b usiness associated with the treatment and supply of reclaimed water. This paper briefly examines the main sources of legal risk for suppli ers of reclaimed water and suggests ways to manage those legal risks so as to reduce the potential for legaJ liability. Although the paper is based on the regulatoty framework applying in Victoria, the general legal principles discussed are of interest fo r all jurisdictions in Australia.

Potential Impacts T h e Victo ri a n Guidel in es fo r E,wironmental J\llanage111ent: Use efReclai111ed Wat er (th e Reclaimed Water Guidelines) produced by the Victorian Environment Protection Authority (EPA) provide an overview of the potential impacts arising from the supply and use of reclaimed water. These risks include: • Environmental Harm - adverse impacts on soil, groundwater and surface water as a result of n utrients, salts, pathogens and other contam.inants present in reclaimed water; • H arm to Human Health - as a result of exposure to pathogens and other contaminants by consun1ing reclaimed water; • H arm to Livestock - as a result of stock being exposed to pathogens and conta m.inants in reclaimed water where it is used to irrigate pasture or fodder crop s; • Food Safety Risks - m.icrobial or chemical contamination of produce or food arising from the direct exp osure of food crops to pathogens or contaminants in reclaimed water; from chemical bio accumulation in animal meat; or from m.icrobiological contamination of milk via exposure of cow teats to pastu re irrigated with reclaim ed water. The extent of these risks in relation to any particular water re- use scheme will depend on:

This paper was presented at the AW A Victorian Branch Conference, Lorne, October 2003.

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• th e sou rce of the influe n t (fo r example, w hether th e sewage stream is so urced from residential or industrial a r eas o r wheth er th e ca t ch m ent receives wastewater fr o m abattoirs or feedlots); • the extent and effectiveness of the treatment process (the higher the level of treatment, generally the less risk of adverse impacts); • the purpose fo r which the reclaimed water is used; an d • the infrastructure used to deliver the reclaimed water. Each facto r needs to be assessed and managed in the context of the re-use scheme in question.

Overview of Potential Sources of Legal Liability Suppliers may incur legal liability under both statute and the common law in relation to harm or loss caused by reclaim.ed water. Potential sources of liability include: • liability for statutory offences under environmental protection legislation; • liability for statutory offences under legislation designed to protect human and stock health; • liability for damages under the common law of nuisance and negligence; • liability for damages for breach of statutory duty; • liability for damages fo r breach of exp ress and implied contractual terms; and • liability under the Trade Practices Act 1974 (Cth). Liability can thus be categorised as common law liability in tort, liability under contract and liability under specific legislation . T hese sources of li abi lity are discussed in more detail below.

Common Law Liability in Tort

Negligence A supplier could incur liability under the common law of negligence in relation to harm caused to persons, property or livestoc k as a result of the supply of reclaimed water. Liability in negligence wi ll arise if a claimant can establish that: • the supplier owed the claimant a duty of care. T his will be so if the relationship

betv.reen the supplier and the claimant was such that a reasonable person in the supplier's position should have fo reseen that its conduct could cause harm to a person like the claimant; and • the supplier breached its duty of care to the claimant, by failing to do what a reasonable person in the supplier's position wou ld have done to avert the harm; and • the claimant has suffered injury or loss as a result of the supplier's breach which is not too " remote". T h e cla imant must prove these elements on the balance of probabilities. Suppliers are likely to owe a duty of care to customers who are supplied with reclaimed water. Suppliers may also owe a duty of ca re to a w ider class of claimants w ho may suffer harm or loss from the supply of reclaimed water (for example, neighbouring land owners and persons who access land irrigated with reclaim ed water) . What a supplier needs to do to disc harge its duty of care will depend on the facts of each particular case. [n essence, a supplier must take reasonable steps to avo id foreseeable risks arising from recla imed water. In recent cases, the High Court has made it clear that it is necessary to engage in a risk analysis to decide whether a duty of care has been breached (see Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54). T he likelihood of a danger occurring, and the consequences if it does occur, must be weighed against the measures that could reasonably be taken to elim.inate the risk, in li ght of the cost, inconvenience and difficulty of taking those m easures.

Nuisance Liability in nuisance could potentially arise where a neighbouring la ndowner's land is affected by pollution of soil or water caused by the appli cation of reclaimed water. Generally, liability in private nuisance rests on the person who occupies the land from which the nuisance emanates. H owever, liability may be incurred by a party who creates a nuisance on land under the occupation and control of another. Accordingly, there m ay be scope for a neighbouring landowner to bring an action in nuisance against the user


BUSINESS

o f reclaimed water, or, in certain circumsta nces, the supplier. Breach of Statutory Duty

If a supplier breaches an obligatio n imposed by statute, it might b e possibl e fo r a p rivate person to bring a civil actio n fo r d am ages against the suppli er. Eith er or both of an action for breach of statutoty duty and an action in negligen ce may be available. In order to successfully sue a suppli er fo r breach of statutory duty, a claimant would need to establish that: • th e relevant legislation imposes a statutory duty o n a class o f persons o f w hich the suppli er is a member; and • Parli ament intended th e legislation to confer a private right to sue for breach o f that du ty o n a class of persons o f wh ich th e cla imant is a m ember. Th e reasoning used by C ourts to establish the intentio n o f Parliament in th ese type o f cases va ries widely. It is th erefore diffi cult to predict whether a C ourt would fi nd that a person has a right to sue if the suppli er fai ls to comply with a statu toty duty about supplying reclaimed wa ter. A Court is probably more likely to fin d that such a right ex ists if it is clear that t h e statutory duty has bee n imposed sp ecifically to protect users of reclaimed wa ter.

limited by the parties in certain resp ects. If the customer has made known to th e supplier the purpose fo r which th e recla imed wa ter is required , th e water must be "fi t for the purpose" for which it was suppli ed. W arranties that th e water is of " merchantable quality" (fit fo r th e purposes of w hich go ods of that kind are normally purchased) and that it corresponds w ith the descripti o n in the suppl y agree ment may also be implied.

There is also potential for a supplier o f recla im ed water to incur liabili ty under Part VA o f th e Trade Practices Act, which imposes a produ ct liabili ty regime that makes corp orations liable fo r the supp ly o f defective goods w here an individual suffers damage. Liability under th e Trade Practices A ct w ill depend on the nature of the water supplier and the custon,er.

Liability under Legislation Liability under the Trade Practices Act

1974 The Trade Practices Aci 1974 (Cth) prohibits a corporation from , in the course o f trade o r co mmerce : • e n gag in g i n co nd u c t w h i c h 1s misleading o r deceptive, o r likely to mislead or deceive (section 52); or • falsely representing that goods are of a particular standard , quality or composition (section 75 AZC( l )) . It is possible that a supplier could incur liabil ity under th e Trade Practices A ct if it has made representations about the quali ty of the rec laim ed water wh ich prove inco rrect.

Suppl iers o f reclaimed water may in cur liability under spec ifi c statutes designed to protect the environment, or human and stock health. The potential fo r li ability will depend on th e requirements of th e legislation in each State o r T erritory. The fo llo w ing sectio n outl ines relevan t provisions o f th e Vi cto rian legislative sch em e by way of example. The Reclaimed Water Guidelines

EPA Victo ri a's R ec laim ed Wate r Gu idelines provide a framework fo r " best practice management" in relati o n to reclaimed water suppli ed from sewage trea tment plants. Failure to comply with th e G uidelines requ irements may result in

Liability under Contract Breach of Express Terms in the Contract

A su pplier may be liable to a custom er for damages if the suppli er does not comply with its express obligations under a contract for th e su pply of reclaimed water (including obl igations about th e quality and quantity of reclaimed water) . Liabili ty wiU depend on the express terms of th e contract and th e extent to w hich the supplier has negotiated exclusio ns or limitations o f liability. Liability for Breach of Implied Terms of Contract

Divisio n 2 of Part V of th e Trade Practices A ct 1974 (Cth) implies vario us cond itions and warranti es into co ntracts involv ing th e supply of goods and services to " consumers" . A breach of such a condition or warranty will give rise to a right for the consumer to sue th e supplier fo r damages fo r breach of con tra ct. If the supply of reclaimed water is charac terised as a supply of a good or service to a " consumer" , th e Trade Practices Act wi ll imply certain warranties into the contract of supply in particular circum stances. These warranties cannot be exclu ded by contract and may o nly be

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suppliers or users incurring legal liability under environmental regulations or the common law. Similar guidelines have been adopted in other States (see for example, NSW G11ide/i11es for Urban and Reside11tial Use of Reclai111ed Wa ter (May 1993) and South A1.1stralian. R eclairned Water Guideli11es - Treated E.ffluent (April 1999)). Th e Victorian R eclaimed Water Guidelines specify th e criteria against which the EPA will assess whether to grant a particular water re-use scheme an exemption from the works approval and licensing requirements of the Environment Protection Act 1970 (Vic). The Guidelines set out general obligations for suppliers and users of reclaimed water. The Guidelines require a water supplier to (among other things): • identify and assess the risks posed by the supply of reclaimed water; • ensure that reclaimed water supplied is fit for its intended use; • ensure th a t an e n v ironm ent improvement plan (EIP) is developed which specifies the m easures that will be taken to ensure the reclaimed water meets required quality requirem ents and is used for appropriate purposes;

• provide information to customers and others abo ut the use of reclaimed water; • provide reliable complaint response procedu res; • undertake auditing of customers to ensure compliance with the EIP requirements; and • develop a supply agreement covering the respective rights and obligations of the supplier and user. T he Guidelines also set out specific requ irements in relation to water treatment and q uality, distribution, acceptable site uses and site specific controls, site selection and environmental m anagem ent, m onitoring and reporting obligations and requirements for environment improvement plans. Potential liability for non-compliance with the Reclaimed Water Guidelines

T he new State Environment Protection Policy (Waters of Victoria) requires the reuse and recycling of wastewater to be sustainable and not to pose an enviro nmental risk. The Policy also requires re-use and recycling to be consistent with EPA Victoria's R ecla im e d Wate r G uidelines.

Failure to comply with the Guidelines will not give rise to a specific offence under the E11vironment Protection Act. However, the EPA has imposed conditions on discharge licences for some sewage treatment plants in Victoria that requ ire any re-use scheme supplied from the plant to comply with the Reclaimed Water Gu idelines. If a supp lier fails to comply, it could be prosecuted for an offence for breaching its licence (subj ect co a maximum penalty of $240,000), and/ or subject to other enforcement measures appl icable under the Act. Pollution Offences

Tl1e Enviromnent Protection Act 1970 (Vic) r11akes it a criminal offence to pollute water, the atmosphere or land in Victoria (maximum penalty: $240,000). There is potential for both suppliers and users to be liable fo r pollution caused by reclaimed water in certain circumstances. In a prosecution for an environmental offence, it is not necessary for the EPA to prove that the defendant acted inten tionally or negligently- merely that it " caused or permitted" th e pollution to occur.

Liability under Health Legislation in Victoria The Health Act 1958 (Vic)

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The Health Act 1958 d ea ls with "nuisances" w hich are defined to include anything which is, or is likely to be, dangerous to health, or noxious, annoying or injurious to personal comfort. It is an offence u nder the H ealth Act for a person to cause a nuisance, or to knowingly allow a nuisance to exist on or to emanate froin any land owned or o ccupied by that person. The maximum penalty is $10,000. It is possi9 le that a supplier in Victoria could be p~osecuted for an offence of causing a nuisance if a person becom es ill because the reclaimed water is not safe for its permi tt~d use. H owever, such a prosecution is probably less likely if the supplier has imposed restrictions on use which comply with the Reclaimed Water Guidelines and the requirem ents (if any) of the Victorian D epartmen t of Human Services and had taken reasonable measures to reduce the risk of improper use . The Safe Drinking Water Act 2003 (Vic)

The Scife Drinking Water A ct com es into operation in Victoria on 1 July 2004. It contains provisions about drinking water and "regulated water". T he Victorian Minister for H ealth may declare water which is supplied to the public in circumstances in which it may be mistaken


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fo r drinking water to be "regulated water" . T he Victorian Department of Hu man Services has indicated that reclaimed water may be considered for declaration as "regulated water" . If reclaimed water is declared to be " regulated wa ter", the Safe Dri11ki11g 14'ater Act will require a water supplier to : • take all reasonable steps to ensure that the intended recipients of the water are made aware of the natu re of the wa ter and any health risks which may arise from its use; • prepare, implement and conti n uously review a R isk Management Plan in accordan ce with Part 2 of the Act. The supplier may also be required by the Secretary to the D epartment of H uman Services to have the plan audited fro m time to time; and • pro vide the Secretary with an annual report relating to the quality of regulated water. Liability under stock protection legislation in Victoria

It is an offence under section 42( 1) of the Livestock Disease Control A ct 1994

(Vic) for an owner o r occupier of land to allow cattle to graze on land on which sewage has been deposited , subject to certain exceptions (Penalty: S6,000) . Section 42(2) of that Act makes it an offe nce fo r a person to permit, suffer or allow any cattle or pigs to be fed with any pasture or crops grown on land on w hich sewage or night soil has been deposited or spread, except with the app roval of th e Sec reta ry to the D epartm ent o f Sustainability and Environment. Pigs are not permitted to graze o n land irrigated with wastewater. Sub-sections 42(1) and (2) do not apply to a " sewerage au thority" that permits ca ttle to graze on land , or to be fed with pasture or crops grown on land, where the land is o w ned or occupied by the sewerage authority. "Sewerage aut h or i t y" i s d e fin e d t o m ea n Melbo urn e W ate r o r an autho rity under the Water A ct 1989 (Vic) that has a sewerage distri ct under that Act. A "sewerage autho rity" does no t include li ce nsees under th e Wal er fo dustry Act 1994 (Vic) .

The prohibitions under section 42(1) and (2) also do not apply if the night soil o r sewage has been purified to the standard approved by the Minister by O rder published in th e Vic to rian Gove rnment Gazette. The cu rrent purificatio n standard in relatio n to ca ttle is that se t out in th e Ministerial Order gazetted on 9 J anuary 2003 (Victorian Government Gazette G2, at page 42) . Liability under Food Protection Legislation in Victoria

T he Food A ct 1984 (Vic) creates a series of offences regarding the sale and handling of " unsafe" and " unsuitable" food. The user of reclaimed water is probably more likely than a su pp lier to be liable fo r an offen ce under this Act if the irrigation of food crops with reclaimed water ca uses food to become " unsafe" or " unsuitable" .

Practical Management of Risks Ultimately, a supplier's legal exposure w ill depend on its ability to minimise the risk of harm actu ally occurring, either by:

Discover the difference! Tho Aquatoo Pro11ure Sewer Pump Station 11 the r11ult of over 30 year, of t)(pertl11 In tho domt1tl0 and munlolpal 1twer market. Although the pre11ure 1twer concept h111 been around In tho U,S, for ovor 30 year,, Aquatoo havo dH lgned II paokago u1lng 100111 ll)(pt rlonoo to 1ult Au1tr1llan 00ndltlon1, Tho Aquatoo polyothylono pump ohambor ha1 bHn onglnH rod from tho ground up to bo 011y to ln1tall, plu1 It m11t1 or l )(ottd1 all applloablo Au1trallan 1tandard1, Tho earnoe UltraCAV progro11lvo cavity grlndor pump h11 won r11poot world wldo for 111 rollablllty In dlffloult 00ndlt10n1, Coolor motore 1111longor, That'• why Aquato011 fully 1ubmorelblo motor uao, a harmlo11 dlolootrlo mlnoral off for ooollng, It 11 up to four tlmH moro offlolont than air ooollng, Tho lntogratod prouuro 1wlt0h (optlonal) monltor1 dl10h11rgo pro11uro1 and 1hut1 tho motor down long bolero II thormal out,out would, o,ctondlng 111 oporatlonal llfo, Tho Aquatoo olootrloal oontrollor 11 manulaoturod to 1trlngont Au1trallan Stand11rd1 u1lng off tho1holl 00mponont1 that maku It 1tralght forward and troublo lroo, Aquatoo offor, you moro oapaolty option,, providing a largor oapaolty abovo alarm point. ""ull tho plug from tho bath without II worry," Wo bollovo that wo'vo got a bottor 10lullon for ovory domandlng ln1tallallon you'ro ovor llkoly to faoo, l:1ut don't tako our word for It, put u1 to tho tu t, Call now and dl1eu11 your partloular nood1 with ono of our quallllod onglnoor1,

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• treating reclaimed water to a level where it does not pose any risk to human or livestock health or to the environment. This is likely to involve significant costs and may not be practical or possible given the influent stream; or • treating reclaimed water to a level which is suitable for the particular purpose for w hi ch it will be used, and taking reasonable steps to ensure that the reclaimed water is used appropriately for that purpose. The nature of approp riate risk management measures will depend on the particular water re - use scheme in question. Measures which are likely to assist a supplier limit its potential legal liability include: Inform customers of known risks

This may involve providing education and information to customers about particular risks associated with the re-use scheme. A supplier could also seek to include an express acknowledgment from the customer of potential risks in the supply contract. Implement reasonable measures to ensure that foreseeable risks are minimised

A supplier should undertake a risk assessment to determine what measures can reasonably be implemented to minimise the risks associated with a particular re-use scheme. This would involve an assessment of the likelihood of a hazard occurring, and the consequences if it does occur, and weighing

those against the measures that could be taken to eliminate the risk.

indemnities from the customer for liabilities incurred by the supplier.

Comply with the Reclaimed Water Guidelines

Conclusions

Compliance with the Guidelines 1s likely to redu ce the risk of harm arising, and assist a supplier establish that it has complied with its duty of care by undertaking reasonable measures to reduce the risk of harm. Keep abreast of scientific knowledge

It would be prudent fo r a supplier to keep abreast of new scientific knowledge concerning the use of reclaimed water and any associated risks. If evidence comes to light about new risks, a supplier should advise customers of those risks and implement additional risk management measures to address those risks. Ensure the supplier has appropriate contractual and/ or statutory rights to implement risk management measures

A supplier needs to ensure it can rely on contractual and/ or statutory rights to manage risks arising from th e supply of reclaimed water. For example, a supplier will want to ensure that the customer is obliged under the supply contract to comply w ith restrictions on the use of reclaimed water and that the supplier can monitor compliance with those conditions. A supplier may also wish to contractually exclude or limit its liability for the supply of reclaimed water and seek

Suppliers must carefully assess the additional risks associated with the supply of reclaimed water and implement strategies aimed at reducing their potential legal exposure. Where reclaimed water is treated to less than a potable standard, there are two main areas of exposure for a supplier: • where the reclaimed water has not been treated to a standard which is suitable for its permitted use by the customer; and • where a customer or third party misuses reclaimed water contrary to restrictions imposed on use by the supplier. To minimise its risk of legal liability, suppliers of reclaimed water should implement measures to address both areas of exposure, to the extent possible. This requires suppliers to undertake a risk assessment which is specific to the particular re-use scheme being supplied and implement practical risk management measures designed to m inimise the occurrence of the risks identified.

Bibliography

Water Resources Strategy for Melbourne, 21st Century Melbourne: A WaterSmart City, Water Resources Strategy Comrnittee for the Melbourne Area, 2002 New Water for Victoria: Victoria's Water Recycli11g Actio11 Plan , Departmen t of Natural Resources and Environment, October 2002 Securing our Water Future: Green Paper for Discussio11, Victorian Government Department of Sustainability and Environment, August 2003. C11ide/i11es fo r Enviro11111e11tal COST-EFFECTIVE WAY TO SAVE LAND, RETICULATION Ma11age111e11t-Use of Recycled Water, MOST IMPORTANTLY ALLOW REUSE OF WASTEWATER EPA Victoria, September 2002

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WATER DECEMBER 2003

Lisa Moore is a Senior Associate with the legal firm of B l ake Dawson a nd Waldron. (Level 39, 101 Collins Street, Melbourne). She primarily practises in the fields of water legislation and environmental compliance. Email lisa.moore@bdw.com. Address: Cl- Blake Dawson Waldron, Leve l 39, 101 Collins Street, M elbourne Victoria.


WASTEWATER

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WASTEWATER MANAGEMENT AT SHEPPARTON, VIC A Jovcic, A Tyson, B Hammond Abstract I n enla r g ing the Sh eppa rton Wastewater M anageme nt Fa cility, Goulburn Valley Water has adopted an holistic approach to suit the changing environment of regulation and environmental responsibility. R evised agreements w ith the major trade waste customers have enabled long-term financial sustainabili ty. R eclaimed water use is balanced against water and nutrient needs and the sustainable application of sodium. At the same time this water use generates significant revenu e. R eclaimed water is only discharged to the Goulburn River whe n absolutely necessary and only after undergoing innovative tertiary treatme nt by the new Actiflo process to limit phosp h o ru s load in g o n the waterway. In practise, one could argue that the inflow of such highly treated water is improving the quality of the receiving river. A st ate-o f-the- art High R ate Anaerobic Lagoon (HRAL) facility is curre ntly under construction and will address organic overloading and the associated odour issues that the previous plant design could not accommodate. In this process methane gas will be captured and flared. T here is also potential to utilise this renewable energy source for cogeneration of electricity and further benefit to the environment through carbon offsets. By utili si ng innovative methods, embracing advanced technology with flexible contractual systems , GVW will conti nue to deliver high quality, cost effective and environmentally sustainable services to its industrial and residential custom ers in Shepparton into the future. Key Words: Reclaimed Water Irrigation,

T ertiary Treatment, Actiflo, High R ate Anaerobic Lagoo n , Trade Waste Agreem ent, Sustainability, Innovation, Partnership.

This paper was presented at the AW A Victorian Branch Conference, Lorne, Oct0ber 2003.

Lagoons River Tertiary Plant

HRAL Irrigated Woodlots Mâ&#x20AC;˘Jor Irrigated Pasture

Figure 1 . Aerial photograph of the Shepparton WMF.

Introduction

Faclllty Overview

R egulatory change due to evolving triple bottom lin e (social, economic and environmental) fa ctors has a maj or influence on the way GVW develops and operates it WMF's. The past has shown that an imbalance often results in significant capital expenditure without equal consideration of the necessary increase in revenue to provide long term economic sustainability. In 1970, the Shepparton WMF was relocated to its current location at D aldy Road, Shepparton, in order to provide a site with adequate land area and an environment for long-term wastewater management. T he new plant was based on a series of anaerobic, faculta tive and evaporation lagoons to treat domestic sewage and principally food industry trade wastes. Over the years additional lagoons have been added to the plant. Improving knowledge, as well as new laws and regulations, have changed the goals of the treatment processes. This paper will discuss the innovative technical and policy decisions GVW has impl e m ented in mana ging the Shepparton wastewater syste m in order to keep abreast with the influence of triple bottom line facto rs and resulting financial pressures. R elevant infrastructure d elivery methods are also discussed.

Shepparton, l ocated in central Victoria, is at the heart of the state's fruit processing region. Flows to the WMF are largely from this activity and vary significantly in volume and o rganic load throughout the year. The p eak inflow season is typically between February and May and corresponds with the annual fruit canning season. The average flow to the plant has increased from around 5 ML/din 1970 to 18 ML/d, w ith an existing peak inflow of 33 ML/d of which 80% is attributable to maj or trade waste food processing industry. From the 1970's to 1986, all reclaimed water was discharged directly to the Goulburn Rive r. In 1986 the first pasture irrigation areas were developed followed by a number of irrigation trials with tree plantations from 1989. The proportion of irrigated reclaimed water increased over the years although, during the winter months, secondary treated effluent was still discharged directly to the Goulburn River. From the mid-1980's, high seasonal fluctuations in wastewater flows and loads became the norm due to changes in production of the major trade waste customers. This saw a high variance in WMF p etformance and reclaimed water quality and also contributed to odour problems at the facility and in neighbouring communities. At the same time the larger community, the Victorian Environment Protection Authority (EPA) WATER DECEMBER 2003

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and GVW gave more attention to the impacts of high T otal Phosphorus (TP) and nutrient loadings on the Goulburn River. A taskforce consisting of EPA and GVW reviewed the plant fac ilities in the mid 1990's culminating in GVW developing a M aster Plan for th e Shepparton W MF. Th is h as r es u l t e d in th e construction o f a $4M tertiary treatm ent pl a n t in 200 1 a nd th e r ece nt conunencement of a $17M HRAL facility upgrade . Financial Sustainability

The do1ninant lo ads on the WMF nece ss itating the rece nt significan t investment in new infrastru cture and operational p ractices rela te to tra de wastes. This investment has placed a heavy financial burden upon the Authority. A key initiative towards economic sustainability was achieved in 1998 w hen the Authority's regional Trade W aste Poli cy was modified to intro du ce an equitable user- pay pricing regime. This has allowed th e recent capital works at th e WMF to pro ceed within a framework ofl ong-term financial surety. The Policy establishes cost contributions based on each individual industry's impact o n wastewater infrastructure and operatio n. Thro ugh load based pricing, the Policy also enco urages indust1y to minimise waste discharges (and therefore water use) which complements GVW 's o verall go al of respo nsibl e reso urce managem ent. H istorically, GVW had entered into lo ng term (ie 40 yea r) trade waste agreem ents with industry w hich adopted the accepted standards o f the day. With th e passage of time , agreem ents of this nature became increasingly irrelevant and difficult to administer for the following reasons: • Progressive in creases of 0ows and loads due to industry growth. • T he Authority did not wish to stifle indumy growth b ut needed to ensure financial and environmental sustainability . • Trade waste exceedance requirem ents were inappropriate and difficult to administer. • The requirements relating to allocation of works and upgrades were not based on a strong agreement with the industries. The trade waste usage charges were not reflective of true operational costs. • The timefram e for agreement reviews w ere excessive . • No incentives for waste minimisation or cleaner produ ction were incorporated into the agreem en t. The modified agreement fram ework emb races "Pay for Use " principles. Operating costs, capital charges, finance 76

WATER DECEMBER 2003

and administration charges are appli ed to individual wastewater systems throughout the Authority's region. Fees and charges re flec ti ng a cap acity sh are of the wastew ater system is the underlying principle of th e Policy. In additio n, risk related to changing environmental goals is shared between the Authority and trade waste custo m ers through the charging philoso phy. A two part charging structu re was developed incorporating 'capacity charges' and 'usage charges' . The Trade Waste Agreement allows industries to pay the capacity charge either upfront or over agreed terms. In addition, load based usage charges encourage waste minimisation , particularly from the large fo od based industries. The best way to demonstrate the impact that the modified policy has had on industrial custom ers is to consider the recent upgrades at the Shepparton WMF. Prior to policy review, the majo r industries in Shepparto n contribu ted arou nd $300,000 per annum to the Authori ty for all trade waste co nsiderati o ns. The same industries now pay aro und $ 1M per annum in usage ch arges and ha ve co ntributed around $6M in capac ity charges towards the rece nt infrastru cture upgrades at th e facility. This increased industrial revenue, in combination with revenue from domestic customers, enables th e long term fundin g and op eration o f the Au t h o rit y's S h e p parton w astewa t e r sys te m to approach eco nomi c sustainability.

Reclaimed Water Use & Tertiary Treatment A key direction set by the State Environment Protecti on Policy (SEPP) released in 1988, was a preference to direct reclaim.ed water to land based irriga tion . Through close cooperation with the EPA, GVW established the Shepparton WMF Master Plan in th e mid 1990's. Th e plan established a range of improve ments to ensure environmentally sustainable perfo rm ance for the facility. It comprised a balanced solutio n to reclaimed water m anagem ent o f irrigatio n to agricultural and fo rested land for the bulk of water produced in addition to tertiary treatment and return to the Goulburn River for the residual. W orking in partnership with th e EPA provided a high level of certainty for the Authority in terms of en vironmental go als to be achieved facilitating more effec tive system aug m e ntation and economic planning. Sustainable application of reclaimed water to land is a critical component o f the operation at th e Shepparton WMF. However, the Master Plan id entified that

full land bas ed reuse w as not practical or cost effective having regard to annual climatic variation and a need for discharge to river in very wet years. Fu rthermore, studies around this time indicated that the acc umulation of so dium and rising regional aquifers were a major issue fo r lo n g term environmental and economic sustainability o f to tal land based reuse . Consequ ently a balance between land based irrigation and discharge to the Goulburn River w as still necessary. In coming to the decision to continue recycling a porti on of the WMF ou tput to the Goulburn River, existing environm en tal issues ass o ciated with Total Phosphorus (TP) and Suspended Solids (SS) loa d in gs r eq uire d att e ntion. C onversely, Total Nitrogen (TN) was not considered to be adversely impacting upon the enviro nment and did not nee d attentio n. T he Shepparton W M F M aster Plan addressed the key issues through the ado ption of the option to invest in a chemica lly assisted tertiary treatment process to achi eve the required TP and SS rem o val. Studies at this time show ed that the receivin g waters o f the Goulburn River already had very high levels of phosphate a nd th e point d ischarge fr o m the Shepparton WMF was co n tributing around 8% o f the total estimated 400 ton ne phosphate load fro m th e Go ulburn River C atchment. GVW recognised that all reasonable steps sho uld be taken to reduce this load and a tertiary treatmen t plant was co mmissioned in 2001 . The tertia1y plant has had the net result o f reducing the TP input from the WMF from 8% to less than 1% o f the total load in th e rive r. This e nvir o nm e nta l improvement has come at a capital cost of around $4.0M with an annual operating cost of $0.9M. In doing so, G oulburn Valley Water has thrown down the chall enge to other TP contributors in the catchment to recognise th eir o bligations and ac hieve commensurate redu cti ons o ver the coming years.

Tertiary Treatment Process (Actiflo Plant) In order to optimise tertiary treatment process selection, GVW co ndu cted a technology review and a number of laboratory trials. B ased on th ese trials, Dissolved Air Flotation Filtratio n (DAFF) was initially selected as the preferred process option. Project deli very utilised D esign and Construct (D &C) m eth odology, indi catin g the preference for DAFF . Alterna ti ve processes w er e encouraged to be offered , subj ect to meeting the rigorous performance criteria


WASTEWATER

specified. This approach resu lted in several treatment technologies being tende red, including DAFF, Induced Air Flotation (!AF) and Actiflo. After extensive consideration, the Authority accepted Veolia Water's (formally Vivendi Water) tender for an Actiflo Plant for S3.8M. While the Actiflo process is widely used across Europe to treat many types of water and wastewater, this was the first applicati on in the world to treat eilluent heavily laden with algae. It was also the first application of the technology to treat wastewater effiuent in Australia. In overview, a raw water pump station transfers secondary treated effiuent from the final lagoons to the tertia1y plant. Due to the variable algae loads and diurnal variation in pH that results, acid is used for pH correction prior to addition of fe rric salt (either sul fate or ch loride) as the prim ary coagulan t. Dosage is variab le depending upon raw water quality and is largely based on the need to ach ieve the SS le vel w hile considering the requ ired TP leve l. The chemically dosed water is then introduced to the Actiflo tank where polymer and micro-sand are added and slowly agitated to form a robust floe. The stream is then clarified via th e up-flow clarifier, followed by graviry filtra tion and pH adjustmen t with caustic soda prior to river discharge . T h e physiochem.i ca l process combines the b enefits of weighted flocc ulation (mi cro-sand en hanced) and lam ella settli ng. This facilitates much higher hydraulic loading rates than other clarification pr ocesses and permits a significantly smaller 'footp rin t' than co mparabl e technologies. Constru ction works commenced in August 1999 and were completed by the extended completion date of November 2000. H owever, Practical Completion could not be awarded until som e two yea rs later due to problems during commissio ning. As with all D esign & Construct (D&C) projects, it is critical that the d esign parameters and performance crite ria be properly formulated and clearly specified. A feature of this contract was th e need to successfully comply w ith a rigorous multistage Commissioning and Proof-Of-P erformance (POP) regime . This p rocess gave the Authority added surety of the contractor's continued in volvement to ensure a successfully operati ng plant. The repeat failure of an important PO P stage marked a critical point in contract delivery and the relationship between the co ntr acto r and the Author i ty. Negotiations were necessary to resolve the

Shepparton Wastewater Management Facility Tertiary Treatment Plant Lagoon Syo<om

-

VIVENDI

water_ . _ ...

Lagoon System

.......'MhÂť

Figure 2. Shepparton WMF Tertiary Process Schematic.

way forward and to the credit of both parties, the negotiati ons were undertaken in an objective and concili atory manner wh ich enabled a satisfactory agreement to be formulated. Essentially, it was agreed that the contractor was to in vest further significant capital and GVW wo ul d relax an aspect of the required plant discharge water quality. This was a good outcome for both parties as the contractor was concerned about repeat failures given the va1iable raw water qualiry expe1ienced and wanted so me surety that the additio nal investmen t wou ld satisfy the Autho rity's requirements . Th e Authority was also satisfied as the outcome presented m.in.imal risk considering that past plant discharge water quality.

Wh il e i t h as taken longe r than expected to complete the project, the Authority now has a tertiaty plant that is operating satisfactorily and to the agreed perfor mance criteria. An impo rtant part of the contract process was the provision of thorough D &C doc umentation. H owever, equally important was the partnership approach adopted for contract negotiations. This w as a key aspect which ena bled the contract to b e completed to the satisfa ction of all parties.

High Rate Anaerobic Lagoon Process The Shepparton WMF M aster Plan also identified the need to address organic

Figure 3. Shepparton WMF Tertiary Treatment Plant. WATER DECEMBER 2003

77


WASTEWATER

overloading of the lagoon based faci lity and the resulting odour issues du ring periods of high industrial activity. GVW adop ted a HRAL facility as th e p referred augmentation alternative. This technology was identified as a cost effective method of treating the m edium strength industrial wastewater received at the plant while incorpora tin g effective odo ur m anagement wo rks and minimising greenho use gas emissions . Once the new 200ML facility is completed in early 2004, GVW will lead the way in HRAL techn ology. The lagoon is being constructed as a 'green field ' proj ect and will be the largest of its typ e in Australia (S H a). It will become a big brother to the existing 30ML & 70ML HRAL 'retrofi t' installations at the Authority's Tatura and Mooroopna WMF sites. The process is designed to provide intimate contact of wastewater with ac tive biomass to optimise anaerobic treatment efficiency, thus minimising the size of the infrastruc ture re quired. Biological breakdown and solid- liquid separation are achi eved in the various sections of the HRAL. The following figure outlines the HRAL process and fun ctional layout. T he anaerobic HRAL process o ffers signi ficant advantages over the alternative aerobic processes (i. e. activated sludge) including: • E xtremely low energy requireme nts. • Very low biosolids production. • Ability to cope w ith extremes of wa stewat e r load i ngs (COD/ BOD loadings, but not pH and salt) as the industrial loads varies throughout the year. • Significant capital infrastru cture cost advantage. It also offers the following advantages o ver traditional anaerobic lagoo ns, including: • Containment of odour. • R eduction in greenhouse gas emissions. • Able to operate at higher lagoon loading rates, therefore, smaller overall footprint. • Co-generation potential After screening and grit removal the raw wastewater discharges into an active biomass layer in the 70ML reaction zone. T his contact provides rapid breakdown and the generation of biogas. From the reaction zone, the wastewater enters the 130ML two part settling zone to undergo solids separation . Settled biomass is recirculated and mixed with the raw influent . The biogas produced is trapped under th e cover and extracted fo r flaring. 78

WATER DECEMBER 2003

Reaction Zone

Settling Zone

Gas Extraction

t Waslewater

,I

t

Maximise biomass inventory

F lexible Cover

Clarified Effiuent

:r:.

Settled biomass collected and returned

Figure 4 . Shepparton WMF HRAL Process Fundamentals.

Following the HRAL, treated effiu ent discharges by gravity into two existing lagoons retrofitted with hi gh speed aerators as a fi nal treatment process. Th e existing treatment lagoons dow nstream will effec ti ve ly . become dedicated detention and irrigation sto rages. The design of the Shepparton WMF HRAL in corporates many innovative featu res that are included to overcome some of the operational problems experienced at other H RAL facilities. Some fea tures of note include th e pro vision of influent pre-treatment, sepa rate reaction and settling zones, distributed inlet port system, settling zone division wall, mixers in each zo ne, robust biomass/ biosolids recirculation system and bypass option of the raw influent . Th ere is pote ntial to utilise the methane captured under the lagoon cover to co-generate power on-site or as a heat source. It is estimated that around 350KW can be generated and this is sufficient to power the aerators to be installed at the site , reducing greenho use gas omissions. The viability of this cogeneration will be assessed once the

overall performance of the HRAL is confirm ed. Anothe r interes ting aspect is the overall method of contract delivery for construction of the req uired HRAL infrastructure. T he proj ect was originally form ulated to be delivered as a D esign & Construct (D&C) project with a perform ance requ irement essentially based on percentage COD reduction through the HRAL. H owever, this resulted in tende r prices that were significantly higher than expected. Faced with th is, the Authority considered other delivery options w ith varying process and commercial risk profiles, including EPCM (Engineering, Proc ur e m ent and Const ru ct ion Managem ent) and Traditional (full design) delivery. It was concluded that as the Authority has experience in HRAL technology, it was able to va lue- add to a consultant based H RAL design. This approach was adopted enabling acceptance of overall process performance risk and resulting financial b ene fi t. The p roj ec t was eventually packaged to include a fu lly designed civi l works component with the

Table 1. Shepparton WMF HRAL Key Operating Criteria. Parameter

Value

Reactor Vo lume - Total

200 ML

Reactor Vo lume - Reaction Zone

70ML

Reactor Vo lume - Settling Zone

30ML divided in two halves

Peak inflow (ML/ d) & COD loading (kg/d)- Summer

40ML/ d & 120,000kg/d

Peak inflow (ML/ d) & COD loading (kg/d)- Winter

30ML/ d & 40,000kg/d

Hyd rau lic Detention Time

6 days

Gas Production Rate

Approx 0.5 m3 /kg CO D removed

Mean Influent Temperature - Summer

26°c 11°c

Mean Influent Tem perature - Winter


WASTEWATER

Authority pre-selecting nominated subcontractors for the delive1y of specialist D &C packages. The packages include the major project elements of chemi cal dosing, lagoon cover, gas system and mechanical & electrical equipment. D&C methodology was used for these elements to allow inn ovative solutions to be presented. Th e civil works form the basis for the main contract, which also includes overaU responsibility for the management and performance of the nominated subcontractors. The main contract was awarded to T en ix Alliance for around $12 M (whi ch includes nom inated subcontract sums) and is due for comp letion in early 2004. Other compon ents are necessary for the success of th e HR.AL at th e WMF. These include the installati o n of aerators o n subsequent lagoons, a general upgrade of plant pipe work to facilitate the change in operation of the existing lagoons to an irrigation storage purpose, land purchase, the provision of power to the site, lagoon beac hing and an allowance for future aerators and mixers. T hese additional components co ntribute to t he total proj ect budget of around $17M.

Conclusion Th e successful evo lution of th e Shepparton wastewater managem ent system demonstrates how GVW has adapted its polic ies and embraced new technologies to accommoda t e the e nvironme ntal, soc ial and econo mi c fa c tors that inf1u e nc e wastewater management practices. This WMF is now well placed to accommodate current and ex p ected wa s t ewa ter lo ads from Shepparton and its major food processing industries into the future. Aspects such as nutrient removal from river discharges and the increased focus on sustainable reclaimed water irrigation are relevant to this case. W ho in the general public in the 1970's would have worried o r even known about the Greenhouse Effec t ? Now we are constructing covered lagoons as big as the Melbourne Cricket Ground complex to reduce Greenhouse emissions with the potential to reduce further through cogeneration or substitution of heat sources. WMF's have become a co mplex combination of technological processes necess itating holistic and i ntegrated management solutions. The evolution of the Shepparton WMF has demonstrated an adaptive approach by GVW, underpinned by close partnering with all stakeholders from the regulator through to customers and contractors. Working

Figure 5. Shepparton WMF HRAL under construction.

closely with the regulator to establish firm m edium term environmental goals has enabled effecti ve planni ng for staged augmentation of the facility. This has facilitated a clear und erstanding of the financial implications and the development of a supportive pricing pohcy to deliver sustainable wastewater se rvices. The quantum change in trade waste pric ing policy required a close working relationship with key industty partners. In addition, the unique technological infrastructure solutions required flexible project delivery methods and a close partnering with co nsultants and contractors. GVW recognises the importance of sustai nable operations and its recent modification to trade waste policy goes a long way to ensuring the cost of managing industrial discharge is truly recognised and met by trade waste customers. An important risk sharing aspect of the policy is that it includes provision fo r financial contribution from indusuy sho uld work arise from the need for greater capacity or to meet tighter environmental requirem ents. As a leading regional water authority, it is extremely important fo r GVW to understand and d eliver on wider community expectations. H owever, the associated policy, management and infrastructure improvements can com e at significan t cost. Water industry and environmental policy makers al ike must give equal p riority to ensure long term eco nomic susta inab ility in achieving social and environmental outcomes.

Acknowledgements Th e aut h ors wou l d lik e to acknowledge the various GVW staff who contribu ted to this paper, especially Mark Putman - Trade Waste Supervisor and Bruce Ander so n - Mana ger Operations. T he input of GHD Pty Ltd, as the Authority's project consultant on the Shepparton WMF tertiary treatment plant and HRAL projects, is also recognised.

References A g ri cu ltural Victoria. 1995, Nutrient Manage me nt in Irrigated Agriculture, R esearch and Implementation.

The Authors Dr Alexander Jovcic is District Mana ger - Cent r al Was t ewater Treatment, with GVW. Alexander is responsible fo r the overall management of eight WMF's including the Shepparton facility. Alan Tyson is Senior Engineer - Major Proj ects , with GVW. Alan is responsible for the delivety of major infrastructure , including the tertiary treatment plant and HRAL projects at the Shepparton WMF. Bruce Hammond is M anager - Strategic Operations, with GVW. Bruce is responsible for a multidisc ipli naty technical team providing support services to fi eld ope rations, including wastewater system operation. Goulburn Valley Water, 104-110 Fiyers Street (PO Box 185), Shepparton 3632, Australia. Email: mail@gvwater.vic.gov.au WATER DECEMBER 2003

79


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BOOK REVIEW Stormwater Pollution Control. 2nd edition. Roy Dodson. McGraw Hill publishers, ISBN 0- 07017 366- 5 RRP $184 plus p.& h. Available bookshop@awa.asn.au This book is a primer on ensuring that engineers, managers and professionals responsible for sto rmwater control are fully averse of all relevant US EPA regulations, conversant with how field enforcement officers go about their job and how to ensure that practices adopted are fully compliant. While the focus is clearly on USA, this book is extremely useful to Australian p ersonnel because it is so specific and targeted in content. The reader gains information on how to determine which permits are needed, when and

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Water Journal December 2003  

Water Journal December 2003