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Volume 28 No 3 April 2001 Journal of the Australian Water Association

Editorial Board F R Bishop , Chairman l3 N Anderson, R. Considine, W J Dulfer, G Finke, G Finlayson, G A H older, B Labza , M Muncisov, P Nadebaum,J D Parke r.J Rissman , F R.oddick, G R.yan. E A Swinton,

•, Jl/ater is a refereed journal. This sy111bol indicates that a paper has been refereed.

CONTENTS

Submissions Submissions should be made to E A (l3ob) Swinton, Features Edit0r (sec below for details).

Managing Editor P eter Stirling PO Box 84, Hampton Vic 3188 T el (03) 9530 89()() Fax (03) 9530 89 I I

Features Editor EA (Bob) Swinton 4 Pleasant View C res, Wheelers Hill Vic 3150 Tel/ Fax (03) 9560 4752 Email: bswincon@ bigpond.net.au

Crosscurrent Editor

2

3 4 6 8 10 11

FEATURES:

W (Bill) R ees PO Box 388, Arrannon, NSW 1570 Tel +6129413 1288 Fax: (02) 9413 1047 E111ail: brecs@awa.asn.au

AWA Head Office PO Box 388, Artarmon, NSW 1570 Tel +6 1 2 94 13 1288 Fax: (02) 9413 1047

WATER RECYCLING Selected paper s, edited fro m the Adelaid e Co nfe rence, October 2000

18

WATER REUSE IN AUSTRALIA: CURRENT, FUTURE AND RESEARCH:

22

Acomprehensive review MONTEREY COUNTY WATER RECYCLING:

P Dillon

Email: info@awa.asn .au

Water Advertising & Production H allmark Editions PO Box 84, H ampton, Vic 3 188 Level I, 99 13ay Street, l3righton, Vic 3186 Tel (03) 9530 8900 Fax (03) 9530 89 11 Email: hallmark@halledit.com.au

KE Israel

26

Water (ISSN 0310 · 0367) is published in Jan uary, M arc h. April, June. Jul y, September, October and December.

ABN 74 054 253 066

Federal President Barry Norman

Executive Director C hris Davis

AWA

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AUSTRALIAN WATER ASSOCIATION

30

WATER RECYCLING IN SYDNEY: EXPLORING THE OPTIONS: A Gregory

Demand management will be cheaper, at least for the next 20 years WATER 37 ·, LIMNOLOGY OF THREE RESERVOIRS: MACROPHYTES AND CYANOBACTERIAL BLOOMS: AC J og leka r, D Al Bakri, M Chowdhury

42

Two shallow reservoirs did not exhibit blooms ', TRANSPORT OF PATHOGENS THROUGH SANDY SOILS: J K Rawlinson, R S G Toze

Australian Water Association (AWA) ass umes 110

Noting the effect of water quality

responsibility fo r opinions or statements of foc ts expressed by contributors o r advertisers. Editorials do not 11cccssarily represent official AW A policy. Advertisements arc i11cluded as an infonnation service to readers and arc reviewed before publication to

30,000 ML has irrigated lettuce, celery, etc in the past three years ENDOCRINE DISRUPTING COMPOUNDS IN EFFLUENT REUSED IN AGRICULTURE: R Lim, S Ga le, C Doyle, B Lesjea n, M Gibert Is there a concern?

G raphic design: Mitzi Mann

Australian Water Association Inc

FROM THE FEDERAL PRESIDENT: Our New Plans FROM THE EXECUTIVE DIRECTOR: First Step - Big Step? INTERVIEW: Stephen Mills MY POINT OF VIEW: P Sha n ahan , Syd ney Catchmen t Au thority INTERNATIONAL AFFILIATES: AIWA Update INTERNATIONAL REPORT: World Water Day: ANepal Perspective: D J ackson CROSSCURRENT: Water News Around the Nation

BUSINESS 4S

'- CHEMICAL QUALITY ASSURANCE · GIPPSLAND WATER'S JOURNEY:

ensure relevance to the water e11viron111ent and objec-

P R L Mosse and M Colwell

tives of A WA. All m aterial in Water is copyright and sh ould not be reproduced wholly o r in part without

Getting the right chemical in the right place at the right time

the written permission of the General Edit0r.

Subscriptions Water is sent tO all AW A m embers eight times a year. It is also available via subscription.

47 48

MEMBERSHIP MEETINGS

OUR COVER: T/i e 111ajor Jeat11re of tl,is isS11e is 111arer rec)'cli11g. At r!,e A W A Co1111e11tio11 011 April

Visit the Australian Water HOME PAGE Association and access news, calendars, bookshop and over 100 ages of Information at

3rd tl,e l,Vater E1111iro11111e1// Ma11a,~e111e11t A 111ard 111asgi11e11 to Wide Ba)' Wiater, wit!, H(~I, Co11t111e11datio11s to Alb11r)' Cit)' Cot111cil a11d the Ol)'111pic Coordi11atio11 A11thorit)' (OCA) . All i1111ol11e water rec)'cli11g. O11r pl,oto is ef the Water Fear,rre at Ol)'111pic Park, 111/,ere OCA /,as bee11 opemti1i~ tl,eir Water R ecla111atio11 a11d Rec)'c/i11g Scl,e111e si11ce last J11ly. 011 April 3rd 200 I all Cl'ossco1111ectio11s were re111011ed so tl,at 110w all t/ie 450 reside11ces i11 Ne111i11gto11 (rl,e old Ol)'l11pic Village) are S11pplied 111itl, bot/, potable 111ater m,d 111ater reclai111ed Jro111 m11age a11d stom1111atcr. Plwto courtesy of OCA. Photog rapher: Bob P eters.


FROM

THE

PRESIDENT

OUR NEW PLANS At the Ozwater Convention in Canberra, on 3 April, Allen Gale handed over the President's gavel to me. I am hono ured to be able to serve and I congratulate All en for his good work in making som e key transitions for AW A: from a competitive to a mu ch m ore collabo rative organisatio n; fro m an incorporated association to a not-for- profit com pan y (a largely admin istrative issue, but one giving us stronger governance); and from m ee tings often bogged in minutiae to o nes where eve ryone has o pportunities for challenging, strategic thinking. Unlike most of my predecessors, I am not an actively practising engineer, che mist o r scie ntist in w ater. As the managing director of Fisher Stewart (co nsulting engineers) m y real job is essentially a m anagement and financi al one and it's many years since l played a technical role. So, altho ugh I am not goin g to personally weigh into any deep, technical debates, my ski lls lie in an area chat I fee l AWA needs now. We have gradually increased our staff resources over the last several years and we have become involved in an ever-widening range of activities and issu es. Our main reven ue strea ms, though, have stayed narrow, being o ur Ozwater and Enviro Conventions and Exh ibitions, and our member subscriptions. Sustaining a m ultimillion dollar operation on just two key revenue sources is too vulnerable a situation to b e in. We have already m ade a positi ve move to review w hat we offer our Co rporate n,embers (of which my own firm is one): that wi ll deli ver better value co them and , we believe, more revenue to the Association. A key sector there is the m edium water utilities - too small to be pare of th e WSAA group, but large enough to have serious in formation needs in their businesses. Another facet is the fact that we always tied corporate m embers to branches - essential in the early days w hen little happen ed outside th e bran ch purvi ew, but less so now, w hen we have a strong natio nal op eration. We will, I ho pe, have agreed to a ne w range o f corporate membership packages by the time you read this. I am convinced that we ignore the evo lving needs of corporate members at our peril. We have also prepared business plans for and have embarked on the operation of internatio nal busin ess lin es under the banner of O z 111nter Globn/, consisting of internatio nal ter/1110-tours, and web-based information broking. Although AWA Im had good links with peer groups around the world, we have not rea lly capitalised o n that up to now, so the new businesses will add value and di versify revenues. Members will be seei ng a much wider range of activities going on and I hope we w ill w in strong suppo rt. As always, feedback is useful and l' d appreciate direct comments to (bnorman@awa.asn. au). 2

WATER APRIL 2001

Angus Si mpson (SA) and H elen Stratton (Qld). We have some w ise o ld heads and some new, you ng blood. That's a good recipe for a leadership g ro up and I am counting on them for inspired decisio nm aking on your behal f over the co ming two years. Bnrry Norman

Aquaphemera

Barry Norman

An area we have looked at strategically too is train ing. Despite long-established links with operator training in Queensland and Victoria; a key role in W IETAA and vocational training policy; and the delive,y of over a dozen courses at Mt Eliza, we have not had a coherent approach to traini ng overa ll. Initial studies suggested that th e Australian water training market is notoriously thin and patchy, making it infertile ground for any sort of commercial approach. Non etheless, training is one of our co re goals, so we ca nnot walk away from it. During m y tenure, work will be progressing on t hat front and we'll be testing ou r boundaries. Tvvo logical fit.~ could well be som ethi ng in the way of o n- line training, plus some collaboratio n w ith established provid ers. All these ideas, though, cannot detract from our basic conce rn over individual m ember needs. A strong thread this coming yea r will be th e re-examinatio n of how well our membership o fferings match the needs of the majority of members, as well as smaller groups: stude nts, younger people, m ino rity groups (wo men are still poorly represented) and people w ho are now working as sole prac tition ers. The value of post- nominals will be explored and also the potential to create so me sort of catego ry for senior practitioners (fellows?) . At the most practical level, to start with, we will have agreed (I trust) to peg subscription rates this coming year, knowin g that being pushed over the $100 mark by GST last year was not very palatable. T o ach ieve this rather long shoppin g list, I am glad to have th e support of a good Executive team and the newly-appoi nted Board. Th e Executive consists of: Rod Lehmann (Vice Pres ident); All e n Gal e (Im mediate Past President); T o m Belgrove, Davi d Hope and Neil Palmer. The Board is Darryl D ay (NT); R ob D 'Emden (Tas); Margaret Domurad (WA); Ross Knee (ACT); J o hn Langford (WSAA); J o hn Park (Vic); M ark Pascoe (A lWA); R.oger Pettitt (N SW );

Dingle's column in the November/ D ecember issue of W nter was fairly typi cal of the knockers who use hi ndsight to de nigrate the good work of o thers! T h e Snowy scheme was a brilliant effo rt by all involved, has been an e normous benefi t to Australian culture, the economy and our way of life. To suggest that engin eers are fac ing image proble m s because of it, is insu lting the reader's intelligence. Granted we now realise the damage that has been done and are trying to rectify it - mayb e too li ttle, too late . But wh o is to say that increasing flows back into the Snowy will not cause more problems in both riv e r sys t e m s? Sys t e m s rea c h equilibriu m and increasing flo ws into the Sno wy Ri ver may devastate the eco-systems wh ich have adapted. The science and unde rstanding may be better now, but it still has an enormous way to go befo re we are even close to understandin g the cause an d effects o f c hanges to natural system s. But even if the environmental fl ows improve the Snowy, w hi ch we all hope they w ill , the issue is about making the best use of our resources to service the standard of living the majority of th e population see m to want and demand . Like the natu ral systems, man-m ade systems also adapt and not always in th e way expected - o therwise economists an d the li ke wo uld a lwa ys ge t i t ri ght too . Balancing the needs of food, people's livelih oods and nature is incredibly complex and cannot be solved by just tryin g to go back to what it w as. So Dingle, engi neers and the m any oth ers inv olved in the sch e m e, should be very, very prou d of what they have done . A t th e sam e time, we should all be in vol ved in worki ng out w hat needs to be done to m ake it better for us and ou r future generations. Ross Knee


CROSSCURRENT

AWA MEMBER WINS NATIONAL AWARD

Pictured at the dinner are, from left to right, John Park, Tony Priestley, Allen Gale, Mike Muntisov and Trevor Bridle.

AW A m ember Tre vor Bridle, a form e r WA Bran c h Commi t tee m e mb e r re ce iv ed th e presti gio u s Clu nies Ross National Science and T echnology Awa rd at the awards ce re mony in M elbourne recen tly. The M edal was presented by C hairman of th e Ia n Clunies Ro ss M e moria l .Foundation, Hugh Morgan. The award was established in 1991 to recogni se and hono ur people who have made impo rtant co ntributio ns to science and its application fo r the e co no mic, social o r e n vironm e n tal be n efit of Australia.

Trevor received the award for a series of high tech wastewate r tr eatm e nt system s, particularly the " E nersludge" process, he has deve loped over the past 20 years, whic h con verts sludge into biofu el. T he first comm ercial plant has just been commissioned at Subiaco in P erth . Trevor's family togethe r w ith AWA members Allen Gale (FederaJ President), Mike Muntisov (Vic. Branch President), John Park (Board M embe r) and T o ny P riestley (1993 Medal recipi ent) we re present to offer support.

The wate r sharing arran ge me nts for these rivers has been the subj ect of dispute sin ce th e Thomson dam was approved in th e m id I 970s. T he agreem e nt requi res that a scientifi c review must take place w ithin th ree years and th e review will lo ok at th e appropri ate n ess o f the curre nt e nviro nm e ntal fl ows.

VICTORIAN HAZARDOUS WASTE MANAGEMENT

Th e agreem ent also provides for th e appointm ent o f an auditor-type role, whi ch will ensure chat e xtracti o ns are mo nitored so chat both irrigato rs and the e n vironm ent ge t th eir all ocated shares o f th e water. A recent study into the e nvironm ental ÂŁlows fo r th e Thomson and Maca li ste r Rive rs, und ertaken by sc ientists fro m the C R C fo r Fres hwater Eco logy and led by Professor Barry Hart, was instrume ntal to th e directio n o f th is agreem ent. Th e study fo und that interim water all ocatio ns, in place sin ce 1996, were inadequate. lnfonmtion: Sally G ibson T el: 03- 9651 5999

A ne w hazardo us waste manage me nt ac tion plan has been outl in ed by th e Vi c to rian G o ve rnm e nt. Th e pl a n , launched by th e M inister for En viro nment a nd Co nse rva tion , Sh e rryl Garbu t t, fo llows th e Go ve rnment's conside ratio n o f a compre he nsive report prepared by a bi - parti san Haza rdous Waste C onsultative C ommittee. Ms G arbutt said under th e ac tion plan, hazardo us waste landfills will becom e o bso le te in fav our of greate r re- use, rec ycling and recovery of hazardo us waste. " Th e key prin ciples be h in d thi s inn ova tive plan are th e crea tion of new state-of-the-art soil recycling centres and a vety clear commitm ent to the redu ction of hazardous waste at its source," M s Ga rbutt said. " This will m ean that hazardous waste landfills will simply become o bso le te and soil recycling centres will ensure that all the material in th e soil abl e to be re-used will be removed so that th e greate r majori ty o f it wil l be put to productive use."

Th e H azard ous W aste Consultati ve Committee consulted extensively with all sta ke holders an d received community input on key reco mme ndatio ns. Th e resulting vflaste Ma11age111ent Policy (Prescribed Was te), fo rmulated by the Environment Protection Auth ori ty, forms the legal framework for the G overnme nt's n ew w aste manage me nt strategy . It in cludes waste redu cti on targets and classifi ca tion provision s and o utlin es appropriate fo rms o f manage ment. A n ew advisory committee, working w ith th e Office of Major Proj ec ts, and re porting to th e M aj o r Proj ects Mini ster J ohn Pandazapoulos, will identify potential sites for new fa cilities and advise th e Governm ent on all aspects o f dec isio nm a kin g . Th e Ha zardou s Was t e Management C ommittee has recomm ended ch at th e tas kforce be bi - partisan. Expressions of inte rest for so il recycling centres and repositories w ill be call ed fo r earl y chis year. Inform ation: Sally Gibson T el: 03-9651 5999.

Su ccess "'"'"'" P a rt n e rs hip

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Wastewater j aste Management

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Competition Reform

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WATER APRI L 2001

17


WATER

RECYCLING

WATER RECYCLING FEATURE The 1st Australian Water Recycling Conference was held in Adelaide in October 2000, and briefly reported in the January issue of Water. Four significant papers have been selected and edited for publication in this issue . Full versions of these papers, along with the 27 other useful papers are published in the Proceedings, a few copies of which are still available from the A WA office, Artarmon, at $66 plus postage.

WATER REUSE IN AUSTRALIA: CURRENT, FUTURE AND RESEARCH P Dillon Abstract Wa ter reuse fro m sewage treatment plants in Australia in 2000was 17 1G L (ie . 11% o fS TP efflu e nt) and gro w in g by 28 GL/yr, T his at last o utstrips th e national increase in ST P efflu e nt . . The adoption o f wa ter re use is mu c h fas ter than had previously been predic te d du e to a numbe r of recent drivers fo r c han ge in w ater managem e nt. Reu se p lans for storm w ater and irrigatio n drainage, with some exceptio ns, are currently sparse. This paper summarises th e resea rch needed to facilitate water reuse and ensure that public and environmental heal th are protected as identifi ed through a survey w ith respo ndents from all states and the N orth ern T e rritory. A cross-section o f c urrentl y u ncoo rdinated A ustralian research in water reuse is also prese nted also fro m all states and the N orthern T erritory. A crosssectio n of c u rren tl y un coo rd in ated Australian research is also prese nted.

Introduction ln September 1999, the Australian Water Ass o ciati o n form e d a spec ia l interest gro up , the W ater Recyclin g Forum , to foster improved communication o n w ate r recycling and reuse in Au stralia (Ande rson (ed. ), 1999) . With two- th irds of the population inhabitin g the fi ve largest citi es, Y 3K compliance w ill dem and that Australians have a ne w visio n for wa ter reso urce ma nagem ent (Harris, 2000). W ater has never been a single use produ c t, and in man y areas, tren ds in w ater consumption ar e u nsus t a i na bl e and a dap t i ve manage m ent o f wa ter will be req uired to sustain economic growth (T homas ct al. , 1999) . A series o f events in the late 1990's converged to rad ically accelerate impleme ntation o f wate r recycling. • An awareness o f en vironme ntal £lows began to e merge in w ater resources manage ment policy • T he deteriorating state o f rivers, coastal and estuarin e w aters has led to imposition 18

WATER APRIL 2001

of limits on nutri ent di scharges to th ese water bodi es and im proved trea tm en t prior to marin e disposal. Subsequently the Federal Government's C lean Seas Program (to impro ve t h e qual it y o f wa te rs dischargin g to the coast) bro ugh t o ppo rtL111i ties to sell rec la im ed wate r o f improved quality as an irrigation resource . • T h e CO A G co mp e tition p oli cy brou ght w ith it a w ave o f new pri vate secto r investme nt in wate r infrastructure and th e adoption of a wider range of tech no logies in wastewater trea tm ent (eg. dissolved air flotation , 111icrofiltratio n, activated carbo n filtratio n , reverse osmosis and biological nutrien t rem oval). Th e co mbin ed e ffect of these facto rs has resulte d in an e xpon e ntial grO\,v th in the availability of high er quality reclaimed water and o pportun ities fo r water reuse. In th e three yea rs to 1998/99 annual capital investment in wastewater trea tment trebled to S 195M and is expected to reach $300M in 2000/0 I (W SAA , 1999) .

Recent History and Projections of Water Reuse in Australia The 1994 estimate o f direct reuse of sewage effluent (Thomas ct al. , 1997) was 18 GL (1%) with growth to 64 GL (3%) in 2020. T hese figures exclude d land treatme nt. Tho mas <'I al. regarded th ese proj ections as mi nima, based on confirmed sc hemes or adopted ta rge ts, and suggested that if th e recommendations of their report ·were adopted reuse figures would increase. O ve r th e same pe riod annual sewage volumes we re p roj ected to increase by 800G L (nearl y 50%) and the in crease in discharge of e ffiu e nt to coastal wa ters by 600 GL (50%), plac ing pressure fo r improved t rea tm ent to contain po llutant loads to t he environm ent. ln a subsequent scenario study (Thomas et al., 1999), to tal Australian water use in 2020 was restri cted to th e esti111ated sustainable yield o f 27,400 GL , and proj ected gross do m esti c product w as maintained by transfers fro m lowe r to higher valued industries and gai ns in water

use effi c ie ncy, with proj ec ted savings in wate r use of 5 ,600 GL (17%) . In creases in urban water use effi c ie ncy thro ugh recyc lin g alon e have poten tial to very significa ntl y exceed ·t 7%, and as urban water consti tutes 22% of current Australian water use, this is a non-tri vial contributio n to sustainabili ty. Urban wate r utilities are lik ely to lea d the way in improvin g w ater use effi cie ncy (Speers, 1999) . R ecycli ng is amon g the most cost-effec ti ve ways o f improving w ater use e ffi ciency in citi es w h e r e wa te r reso urces a re ti g h tl y constrain e d. A survey involving state representatives o f th e W ate r R ecyclin g Forum in 1999/2000 fo und that 113 GL (7%) o f water disc harged from Australian se w age treatm ent pla nts w as reused in 1998/99 (Dill on , 2000) . Based on firm sh ort term projectio ns reuse would increase by at least 28GL/yr/ yr, to dou ble in 4 yea rs, passing 11% in 2000 (Table I) a nd signifi ca ntly e xceedin g T ho mas's 1994 proj ecti o ns, Accordin g to W SAA ( 1999) there was an increase in th e annual volume of effiu e nt reused o r recycled by - 13GL fro m 1997/ 98 to 1998 /99 . T here has bee n a uniforml y s t e ad y in c r e ase i n t h e proportion of w astewate r re used for large w ate r utilities in Au stralia (T ables 1 and 2) . H owever, the starting points have been ve ry d iffere nt, w it h som e clea r leade rs in the fie ld. O nl y three of t h e largest 2 1 w ater utilities re used mo re than I 0% of th eir wastewa te r: G o ulburn Valley W ate r re used 72'X, in 1998 / 99, C oliban W ate r 41 %, and M e lbourn e W ater 19% (mainly at th e W este rn Treatme nt Plant). l n t h e sa me year three no n- major urba n water utilities (NM U 's) ach ieved 100% re use; Albury, Bathurst and Lower Murra y. NMU % re use c urrently exceeds that of maj o r urban utiliti es. In t he dry low-de nsity cities su ch as P erth , Ca nberra and Ade laide, e ffiu ent disc harge is o nly abo ut 50% o f th e main s w ate r infl ow, as the o th er half of w ate r is use d o n gard ens and parks. If irrigation water we re supplied as reclaimed water via


WATER

RECYCLING

Table 1 . Water reuse from water utility STP's in Australia in 2000 and rates of increase, based on 1999/2000 short term f irm projections region

effluent yr 2000 GL

reuse yr 2000 GL

reuse %

rate of increase In reuse effluent GL/ yr/yr GL/ yr/yr

QLD NSW ACT VIC TAS SA WA NT

342 560 30 370 43 91 115 21

54 65 0 .7 25 1.3 15 7.8 2.4

16 12 2 7 3 16 7 11

7.2 3.1 -0.3 3.2 0.3 0 5.5 0

8.0 6.3 0.2 8.5 0.3 2.8 1.2 0. 7

Aust.

1573

171

11

19

28

Water Reuse Research Needs

Source: Susan Leahy (SA). Andrew Mills (NT), Catherine Clark. Max Thomas, David Gregory, Peter Donlon. Peter Byrnes, Pam Kerry (Vic), Peter Szlapinski (ACT), Howard Gibson (Qld), Warren Lee (Tas), John Anderson, Carol Howe (NSW), Lindsay Edmonds (WA), (QWRS , 1999; DPIWE, 1999; Leahy et al., 1998). Raw data summarised in Dillon (2000).

dua l retic ulatio n fro m localised trea tm ent pla n ts, th is would eliminate surfa ce discharges and h,1lve di versio ns of fr esh w ate r from th e cities' w ate r supply catchm e nts. Fo r th e wetter and more de nsel y po pubted cities, exte rio r water use is a sma lle r fraction of wate r d emand , so se w e r d isc harges are a hig he r prop o rtion o f mains wa ter di ve rsio ns (eg Sydn ey 75%) . With the ir de m and fo r urban irri gat io n wate r mu ch sm all er than the suppl y of effi uent, o ther reuses, say, within and b y indu stry, e g fo r coo lin g w ater, piping to rural irrig at ion a re as , o r treatm ent and release to re in vi go rate stream s and w e tlands, arc re qu ired to ge ne rate economic o r e n v ironm e ntal reu se valu e . Co untry tow ns with sew e rage o r common e mu cn t sche m es and surfa ce o r aqui fe r storage, except in ve ry we t areas, are able tO gene rate I 0 0% reuse of reclaimed water for watering golf courses, ova ls, and parks, as we ll as loc al co mm e rc ial cro ps. R e use p rojects and plans fo r urban storm w ate r and rura l irrigatio n drainage, w ith so m e exceptio ns, are cu rre ntly sparse. T hese rep rese nt significa nt o pportunities to gen erate new no n- po tabl e wate r resources in arid areas, w he re such su ppli es ha ve hi gh va lue . Other secrors, no tably mining, are also signifi cant reusers o f w acer (Fi gure 1) and have also bee n increasing reuse (Tabl e 3) . R e cycling the re fore represents a ve ry significa nt ' new' irrig ation or e n vironm e ntal water reso urce, wh ich ma y assist h igh-value d agriculture nea r urban areas . W ith w inte r storage, eith er in aqui fe rs o r surface dams, ch is can represent a valuable economi c commodity, as we ll as having intrin sic values in preser ving e n vironm ental flovvs w here it substitutes for m ains

water use, and in protecting surface wate rs from po ll u ti o n by e limin at ing sewage discharges to se nsiti ve water bo di es. H owever, reuse b y irrigation docs prese nt issues for pro tection o f soil (13ond , 1998; Steve ns et nl., 2 000) and g roundwater (Snow el nl. , 1998) . T o date reuse in Australia has apparentl y been u n impe d ed b y health or e n v iro n mental in cid e nts, an d pu blic acceptan ce of no n- potable reuse has be en high. Guid e lin es fo r re use o f cffiu cnt as we ll as ofbiosolids arc in place in most states and arc integrated u nde r the Nati o nal Wate r Quality M anagem e nt St rategy. H o we ve r th ere a rc man y concerns over the susta inability o f cffiu e nt reuse. It is noted that a fai lure at e ven o ne site m ay d o mu ch to d am age impl em entation of wate r re use nationall y .

Issues in Water Reuse The main issues in water reuse which can have a sign ifica nt e ffe ct on t he continu ed demand for recycled w ater and th e need for re cyclin g arc : • public health • e n v ironm ental sustainability • quality o f fo o d produ cts • so c ial accep tance • trea tm e nt technology capability and reliabil ity • m o nitorin g syste m s • legal liability

A pilot su rvey was undertaken b y th e au thor on be half o f AW A on water reuse resea rch p rio rities, in volvin g on e o r t wo rep rese ntat ives from eac h state a nd ter rito ry. Th e rankin gs that emerged are presented in Table 4. This survey indicates that th e high es t researc h priority was to address pu bl ic acceptan ce of reuse . T h is inc lud es po t ential heal t h effec ts on consu m ers and users and on market acceptan ce of p rodu ce grown with recycled w ater. C ompiling a summary o f cu rren t research w as seen to be a high p rio rity. De mon stration projects at whic h costs were docum e nted w ere al so seen as valuable. Few pri o rit ies w e re d evoted to treatme nt processes, w ith th e exceptio n o f disinfection effectiveness, algae and algal rox in re mo val , and suspe nd ed solids re m o val.

Existing Australian Reuse Research A seco nd qu estion naire o f th e c urrent Australian w ate r reuse research po rtfolio w as circulated in pilot fo rm in Sept. 1999 and reported in D ill o n (2000 ). The p roj ects identi fi ed in th is bri ef survey, w hich is no t c laim ed to be co mprehe nsive, re fle ct an an n ual expenditure o f

$2 .9M. Effec ts o f effiu ent irrigation on soils, plantati o ns o r pastures and eco nomics of pro d uc tion w e re th e subj ec t o f th e m aj o rity o f proj ects. Seve ral d ealt wit h w a t e r b a nkin g in aquife rs u s in g srorm w atc r and rec laim ed w ater. Th ere w ere th ree proj ec ts on community attitudes row ards domes tic w ate r and reuse. An integrated study on coste ffect ive urban w ate r sys te m s was also underway.

Table 2. Percentage of wastewater reused from WSAA and NMU member STPs

• economi cs o f recycling, and • availability of expe rtise. Risks in wate r recycling may be be tte r unde rstood a nd r e du ce d through research tO enabl e be tter guidelin es (Anderson et nl. , 2000), greater public confi-

d e nce, enhanced and bette r fo c ussed in vestment and develo pment, p reservatio n o f natural resou rces, adoption o f appropriate and m o re ec ono mic tec hnologies and g reate r knowled ge w hi ch has an ex port valu e. R esearc h m ay also d efend against investm ent and public confidence inc ide nts, wh ic h if they o ccurre d could ha ve serious impli cati o ns for the wate r industry.

1996/ 97 WSAA

mean median min. max.

4.9 4.0 0 65

1997/ 98 NMU WSAA

6.6 4.7 0 69

n.a.

6 0 100

1998/ 99 NMU WSAA

7.0 5.0 0.1 72

n.a.

10 0 100

Source: WSAA (1999), AWA (2000)

WATER APRIL 2001

19


WATER

RECYCLING

Table 3. Annual volumes of Australian water reuse by sector (GL)

water su pply1

93/ 94

94/ 95

95/ 96

96/ 97

63

69

72

82

24

66 40

97/ 98

98/ 99

110

89

124 102

1 345

1450

WSAA2 * WSAA2 '* mining1

20

20

elec/ gas1

4

5

6

6

other 1

7

7

7

6

94 1222

101 1206

109 1320

134

total 1 effluent2

1 350

Source: 1ABS (2000 ), 2WSAA (1999) * p. ix, **figs 8,8 & 6, 7

A comparison of the pri ority needs fo r research and the types o f researc h resul ts available or curre ntly be ing gene rated show significa nt gaps in reuse resea rch related to health (notably pathoge ns and orga nics), product quality, environ mental fa te of constitu en ts, eco n o mics and so ciology, Eve n in areas wh ere th e re are such projects, these are gene rally focuse d rath er narro w ly, and co mpilati ons o f curre nt know ledge are also needed . Coordinating new and existing proj ects w ithin a national program w ould enhance benefits, and know ledge could be made mo re accessible through the A WA W ate r R ecycling Forum's web page, conferences and newslette rs,

International Research Programs We also need to be aware of, and benefit fro m , researc h in o th er co untries. Seve ral organisations supp ort coordi nated programs o f water reuse r esea r c h. Th e Wat e r En v ir o nm e nt Re sea r c h Foundation (WER F) has a Water R euse Program , w hich by O ctober1999 co ntained 12 projects, m os t a im e d a t improvin g e n vironm e nta l m o nitorin g o f path ogens in reclaimed w ate r, w ith others surveying no n-potable re use managem e nt prac ti ces, and id e n t ify in g th e effec ts o f m ultipl e stressors on aquatic eco syste ms (WERF , 1999) . T he ' W a teR e u se Assoc ia ti o n of Ca liforni a' es ta blish ed the ' TtVr1teR e11se Fo1111 datio11 ' to facilitate R &D a nd e du ca ti o n on wa t e r r ecyc lin g. F ro m 1 998 workshop came six resea rch the mes: public health; water quality ; economics and risk management; treatm ent and ne w tec hnol ogi es; aq uati c

20

WATER APRIL 200 1

e n vironme nt ; and p u blic attitud es. (W ateR euse Assoc of C ali fo rnia, 1998). N o t surprisingly these closely resemble the researc h pri o ri ties id e n tifi ed in th e Australian survey. However C ali fo rn ian inte rests were hi gher in: disin fec tion byp rodu c ts, fa t e o f pha rm ace uti ca l substances, real time pathogen monitoring, contaminant atte nu ati on in so il-aqui fe r trea tme nt, de velo ping a certifi ca tio n process for new treatment tec hnology, use of recycl ed w ater fo r restoration of wetlands and identi fyi ng m ec hanisms fo r ass igning costs to bene ficiari es of water reuse proj ects . W astewa ter reuse resea rc h in Europe is undertaken within indi vidual countries R &D progra ms, and by the Europ ea n

Agriculture 28V,

Elec & gas 5'/4

Forestry 2'/,

Mining 32'/,

Recreation 24Y, Water supply 3Âź

â&#x20AC;˘

Metals W, Other 3Y,

Figure 1 . Reuse of effluent in Australia by economic sectors. Source: ABS (2000).

Commiss io n under the Ke y Ac tio n: 'Sustainable mana geme nt and quality of wa ter ' (European C om111issio n, 2000) . Fourtee n proj ects in this category were fund ed in 2000, most o f w hic h related to reuse of w ater. The thrust of the research co n tinu es to be o r ie n t e d to wa rd s inn ovative wastewa ter treatment methods. H owe ve r th ere is a su bstan tia l body o f research in progress co ncerning m etho ds of m easurement (including bi omarkers) o f endocrin e disruptors, pharm aceutica ls, surfactants , and m etals Table 4. Results of a survey of Au stralian water reuse an d the ir fa te in wastewater research priorities trea tmen t plants and in the Rank Field of Research Theme e n viro nm e n t (Waste W ate r C luster, 2000). Th is retlects th e 1 factors affecting public acceptance of reuse H,E,S substantial qu antities of e illue n t discharged to Europ ean ri ve rs 2 viruses H leading to indirect potable reuse, public health impacts of reuse 3 H and potential ecosystem impacts. H,E impacts on food qu ality of reuse on crops Th e IW A Specialist G ro up 4 pu blish ing a summary of existing research All on Wastewater R eclam ation , economics of reuse Ee R ecycl ing and R e use also aims 5 dis infection effectiveness H to stimulate resea rc h . environmental impacts of reuse E

6

salinity pathogenic bacteria legislation and regulations

E

algae preventio n/ removal impacts on soils impacts on groundwater impacts on fresh surface water sodicity

E E E

H

H,E

H,E E

7

suspended sol ids removal

H,E

8

algal toxin removal packagi ng existing information for regulators cryptosporidium insurance for reuse schemes

H

9

endocrine disruptors impacts on estuarine and marine waters nitrogen

H,E H All

H,E H,E E

Themes: H = publ ic health, S = sociological , E = environment Ee = economics

R&D Gaps for Australia A n d e rson e t al. (2000) suggested an in tegrated intern a t i o na I fr a m ew ork for balan cing risk and affo rdability in develo ping n atio nal gu ideIi n es for wa t e r r ecycl in g . R ec o g ni s in g t h a t o u r kn o wl edge is no t perfect, and that we need to m ake decisio ns based on best ava ila b le informati on, dr aw in g o n th e international know le dge base is vital. An Australi an contributi on is also w arranted , in order to resolve local issues, and if we condu ct research (based o n


WATER

fundamentals) as opposed to only trials (to supply topical solutions) we can contribute in the international arena. An examination of th e resea rch priorities identified in Table 4, shows that some of these are site- specific (eg community accepta n ce, eco n o mi cs), some are regionalJy transferable (eg fate of recycled water constituents within crops, soils, and water bodies say within a biogeoclimatic zone) , and some may be internation ally transferable (eg effectiveness of trea tment tech nologi es) . 1t is proposed that Australian water utiliti es, and natural resou rces agencies of Australian states and the Commonwealth together establish a concerted nation al water recyc ling resea rch program , w hich at less than 1c/ KL woul d provide more than $3M pa to focus recycling research on the most pressing issues and ensure app ropriate commu n ication of research results. T he impact of a fai lu re (eg ep idemic outbreak), loss of land productivity, or fa ilure to curb eutroph ication of fresh or estuarine waters, would have far greater costs loca lly than that of a national program, which wou ld help avert such fa ilures. Developme nt o p portun iti es wou ld be foregone Australia- wide if public opinion tu rned aga inst recycling. A proposal is cu rrentl y in preparation for such a national water reuse research program, linke d wi th int ernationa l programs, and those with an interest in participating in this process are in vited to contact the au thor.

Acknowledgements This review was supported in pa rt by the Australian Water Association and CS lRO Land and Water. Th e contributio ns of the executive of the Water R ecycling Foru m in providing state data an d R.&D pri o ri ti es, and the water research fra tern ity for information on current projects is gratefulJy acknowledged .

References Anderson , J. (ed.) 1999. W ater R ecycling Forum, Water R.ecycling N ews Vo l 1, No 1, Dec 1999. Anderson, J., Adin , A., Crook, J. , Davis, C., Hu ltquist, R., Jim e n ez-C isn e ros, B. , Kennedy, W., Sheikh , B. , and van der Merwe, B. 2000. C limbing the ladder: A step by step approach to international guide li nes for water recycling. p9-1 6, in Proc 3rd Intl. Symp . on Wa stewate r R.ec lamation , R ecycli ng and R euse. Paris 3-7 July 2000, IW A Conf Preprint Book 8. Australian Bureau of Statist ics 2000. Water Account for Australia 1993/94 to 1996/97. Australian Water Association 2000. Performance Monitoring R eport 1998-99, Aust. Non Major Urban Water Utilities. Bond, W .J. 1998 . Effiuent irrigation - an en vironmental challenge for soil science. Aust. J. Soil R esearch 36, 543 - 555 .

RECYCLING

Dillon , P.J. 2000. Water reuse in Australia: C urrent status, projections and research. p99I04 in Water R ecycling Australia 2000, Proc. I st Sy111p. AW A Water R ecycli ng Forum, Adelaide, 19-20 Oct. 2000. CS IR.O and AWA, D Pl WE 1999. Department o f Primary Industries Water and Environm ent. Internal Report European Commission 2000. Cordis - web information on EC programs and projects : http:/ / www.cordis.lu/ Harris, G. 2000. Water Science and ecology in an age of cynicism. Proc of the Xth World Water Congress, 12- 17 March 2000, Melbourne. Leahy, S., M c Intosh, G., v;111 der W ei, B. , and Loan, L. 1998. Use of e ffiu en t and urban scormwater in South Australia 1998: Total water cycle management. $ .A.D ept for Environment Heritage and Aboriginal Affairs, E nvironment Policy Divisio n. Queensland Water R ecycl ing Strategy. 1999. Urban Water R.ecycl ing 13ackground Sn,dy. Unpublished Snow, VO , Di llon, PJ , 13ond, WJ , Smith, CJ, and M yers, UJ. 1999. Effect of plant production system and cl imate on t he risk of groundwater contamination from effi uent irrigation. J. A WW A Water 26 (2) 26-29. Speers, A. I 999. CS Jn.. O's Urban Water Program - A National Approach to Water System Efficiency and Sus tain ability'. Australian Water and Wastewater Association. J ou rnal Water. 26(5) p9- 13. Stevens, D ., McLaughlin , M. , Owens. G, l<elly, J. , Mai er, N. 2000. Agronomic issues when using reclaimed water: Th e Northern Adelaide Plains experience. p55-60 in W ater R ecycling Australia 2000, Proc. I st Symp. AW A Water R.ecycling Forum, Adelaide, 19-

20 O ct. 2000. CS I RO and AW A. Sydney Water. 2000 . l~ecyckd water projection 2000-2005. May 2000. Sydney Water. Thomas, J.F. , Gomboso, J., Oliver, J. E. and Ritchie, V.A. 1997. Wastewater R e-use, Scorrnwater Management, and the National Water R.efonn Agenda. CSI RO Land and Water R esearch Position Paper No I, 203p . Thomas,J.F., Adams, P. , Dixon, P., Hall, N. and Watson, W. 1999. Water and the Australian Economy . Australian Academy of Technological Sciences and Engineeri ng and the Institution of Engin eers, Australia, 127p. Wate l~ e use Assoc of Ca li fornia . 1998. WateReuse Foundation l~eport : Needs assessment wo rkshop results chart future activities. WaterR.euse, Vol 8, Issue 8, Sept/ Oct 1998, p6. Waste Water C luster. 2000. N ewsletter, No.3. Funded by the European Commission-DC XII-DI , Water T echnologies, Water Services Association of Australia. 1999. The Australian Urban W ate r In d ustry. W SAA facts '99 . WSAA, Melbou rne. WEl~F. 1999. web page: http :/ / www. werf org

The Author Peter Dillon is leader of th e Water

n.. eclamation R esearch Group ofCS IRO Land and Water, and a member of the Centre for Gro un dwater Studies, PMB 2 Glen Osmond, SA 5064. He was th e Editor of the Proce edings of " Water R.ecycling Australia" (limited co pies available from AWA Bookshop) . Email Peter. Dillon@a dl.clw. cs iro.au , tel 08 8303 8714.

RESOLUTION ON FORMATION OF A NATIONAL WATER REUSE RESEARCH PROGRAM (Un.an.imo rrsly supported /Jy approx 180 delegates at Water R ecycli11g A 11stralia Symposium, Adelaide, 20 October 2000) Those present support the AWA and the Water R ecycling Forum, in their efforts to estabLish a national research program i11 water reuse. T his research program should aim to estabLish a sound scien tific base fo r guidelines, codes of practice, decision making on appropriate tec h no logy an d tra in ing, improv e methods for evaluating the economics of reuse p rojects in relation to alternatives, provide more usefu l information on society's valuation of reuse and risks, and j ustifiably improve both public confidence and economics of reuse projects. We seek that such a program: • be adeq u ately reso urce d by t he Australia n water industry and state and federal government bodies • engages the best relevant Australian research skills wherever these may be fou nd • e nco urages networ k ing a mong researchers

• is managed by a committee that represe nts th e stakeholders • identifies research priorities in a transpa rent manner • supports high p riority research not supported by other research funding bodies • adds valu e to existin g trials and research projects • ideally in volves all states and territories of Australia • is linked to international reuse research programs • dissem.inates results of Australian and international research in an effective manner to those w ho need it • gives attention to the quality of the research as well as its applicability • operates on m inimum overheads and maximises the research valu e of the program • embraces reclaimed water sourced from municipal effl uen t and urban storm water. WATER APRIL 2001

21


WATER

RECYCLING

MONTEREY COUNTY WATER RECYCLING KE Israel Abstract Afte r almost 20 yea rs of plannin g and stu dies, the M onterey C ounty W ater R.ec ycl ing P roj ects (M C WR. P) started produc tion in early 1998 . D eveloped to reduce seawater intrusio n in N orth ern M on te rey County, this innovative proj ect now irrigates 4,800 H a of food crops such as arti chokes , cele ry, and lettuce. Afte r alm ost three years of operation and th e production of m ore tha n 27,000 M L of recycled water, o nly th e salinity o f th e irrigation water remains as a key co nce rn .

Background The No rth ern M o n te rey C ounty porti o n of the Salinas Va lley is one of the most prod uctive agricultural areas in both Cali forni a and th e world. H owever, it has also been plagued by seawater intru sion for d ecades. T hu s, in the late 70's, the concept of substi tuti ng recycled wate r for crop irri gatio n was proposed as a way to reduce grou ndwate r p u mpi ng. Th e M.o nt e r e y Wa s t e wat e r R ecla ma tio n S tu d y fo r Agr icu lture (MW R SA) was in itiated in 1978. D uring fi ve years of field tests, various crops were irri gate d includin g a rt ich okes, h ead le ttu ce, celery , brocco li , an d cau lifl owe r. In to tal, 96 plots we re needed fo r the va ri ous side-by-side com parisons of water types, fe rtilizer rates, and crops. Th e recycled wate r and produce we re also examined to verify that no pathogens were present. In all, there w ere fo ur ge neral observations: 1. N o vi ruses were fo un d on any of the prod uce sa mpl es 2 . Levels o f natura ll y occurring bacteria o n rec ycled water produce were equ ivale nt to that grown with w ell wa te r. 3. Based on a poli ovirus seeding protocol, fi ve logs of rem o val we re demonstrated by the wate r trea tm ent processes. 4. Metals were not fo u nd to acc umulate in the so ils or plant tissues. It was also noted that produ ce yields and quality were as good as, and in so me cases, be tte r, u sing recycled w ate r. Subsequ e ntly, appro vals fo r using th is water were obta in ed by 1988 fro m b oth the state and Montere y Cou nty and eventually, Bureau of R.ecla mation and 22

WATER APRIL 20 01

C ali fo rn ia low- in te res t loa ns w e re obtained for the US $75 milJi o n proj ect. Th e Mo n t e r ey C ou n ty Wat e r R esources Agen cy (MCWRA) is th e wate r pla nn ing agency for M on terey County. T he M onterey R egio nal Water Pollutio n Contro l Agen cy (MR W PC A) operates a seco ndary treatment pla nt wi th a design capacity of 11 2 ML/ d (current flo w - 80 ML/d). To geth e r, th e two agencies form ed the Monterey Cou nty Wate r R ecycling Proj ec ts (MCWRP) in 1992.

Early Obstacles Funding

Two governm ent low- interest loans were obtai ned , but short-term bonds had to be used as a cash flo w " bridge." Unfortun ately, this in creased bo th overa ll proj ect costs, as well as initial an nual o perating costs. T h e maj or re ve nu e source was an an nual land assessment o f abo ut US$500 per hec tare for the proj ect area. In co ntrast, the assessm ent level in th e southe rn part of the co un ty was j ust a few dolla rs p er hectare . The seco nd sou rce of reve nu e was from a water delivery charge. Eac h m egalitre o f project water initiall y was bi ll e d a t a b o ut US $ 6 .50. (a ppro x A$12/M L). T ogethe r, the tw o revenue streams provid e about US$6 milli o n d o ll a rs a nnu all y . T hese c ha rges are eva luated and adj usted, as n ecessary, each year in order to cover the operational budget. Grower perceptions

As a res ult of input rec eived at mo nthly m eetings, it was fou nd that the m ain grower issu es we re related to food safe ty (pathoge ns), mark etabi lity of th e produc e, public percepti ons, and wate r qual ity.

T he draft irriga tion permit required th e posting o f large " R ecycled W ater - Do Not Drin k " signs every 30111 along the pe ri m eter and interior ro ads o f th e proj ect. T he growers po in ted out that these might in fer that the water was substandard . In essence, if you cou ldn ' t drin k th e water, w hy cou ld you use i t o n foo d c rops. After exte nsive discussio ns, we we re ab le to reduce the sign place me nt to o ne every 500 111. Since most of the parcels were fenced and o n private p roperty , th e word ing on th e signs w as changed to eithe r " Irrigation W ater - D o Not D rin k" or "No Trespass ing." Water safety issues

W hile the M W R SA testin g in th e ¡1 980's lo oked at viruses and gen eral pathogens, it didn't address so m e of th e em erging ones, suc h as E-coli (l57 :H7), cryprosporirfi11111, cyclospom, giarrfia, an d legio11ella. In o rd er to address th ese co ncerns an in d ependen t lab o rato ry compa red recycled water over a threemonth period with a loca l water welJ . T he results verifi ed that th e water was of very hi gh q uality, free of viable pathogens, comparabl e in quality to most drin kin g wate r supp lies and , thus, sui table for foo d crop irrigation. Marketability issues

The opinions of p ro d uce in dustry buyers an d sellers is criti cal an d during 1983 some 80 deta iled trade intervie ws were co nducted in 13 of th e 15 largest grocery chains (5,000 stores). The concl usions we re that there was no reason to label or separate the produ ce gro w n w ith recycled water. Provided tha t safet y o f the p roduct could be ass ured , the buyers felt that co nsume rs wo uld pu rchase th e produ ce. ln 199 7 , w e did an addition al marketabili ty study to see if attitudes had changed. Aga in, prod u ce exec u tives indica ted that labe li ng was not needed. H owever, it was fou nd that produce managers at the store level and consumers had limi ted knowledge of recycled water. Consume rs were surveyed using pic tures of th e produ ce alo ng w ith descriptions of th e water used for irrigation. Aga in , the y were fo un d to be receptive to purc hasing


WATER

produce gro w n w ith recycled wa ter as long as safety wasn't an issu e. H owever, it was found that the terminology used to descri be th e water influenced att itud es . R epu ri fi ed a nd recycled water were fo und to h ave t h e high es t leve l of consu m er comfort. In con trast, addi ng th e term "waste water" resu lted in a less enth usiastic respo nse. A co mmunica tion s co m pany was hired in late 1997 to deve lo p a so m ewha t proacti ve public e du catio n and crisis plan addressing both t he m edia and Figure public w ithi n th e area, in cluding tours, p rese ntatio ns to service clu bs, billin g inserts, a booth at the county fa ir , sc ho o l p rogra m s. To pr e p ar e o u rselves at the natio nal / in te rnati o nal level, we used th e recycled w ater foo d safe ty study as an instrument to discuss o ur p roj ect w i th technica l expert s at headquarter gro ups in Washi ngto n , D.C., su c h as t h e E P A (Env ir onmental Protec ti o n A ge n cy), the Dureau of R eclamatio n, National R esearch Cou ncil, and the U. S. D epartme nt of Agri c ulture.

Tertiary Plant Operations T he te rtiary water recycling p lant was add ed adj acent to the existin g secondary faci lity, incorpo rating coagulatio n, fl occulat ion, mul ti- m e di a fil t ra ti o n , a nd dis infection. Because of daily flu ctuations in gro wer water de mand , a LOO M L (o ne day) sto rage pond is located adjace nt to the plan t. Although the proj ect was ready for o peration in October 1997, test work to dem o nstrate syste m re liabili ty dela yed regul ar operation un til mid-April 1998. 1998 Production issues T he first year of o peration was gea red towards starting slow and ac hievin g a very hig h level o f water q uali ty and safety. Extra testing was conducted to assure that the wa te r was pathogen free. Altho ugh not req uired by o ur permi t, parasite pathogen testing was cond ucted m o nthly . As wi th any new venture , there were also th e usua l O&M issues.

T h e Ca li forn ia Ti tl e 22 tertiary sta n dards have a seve n - da y m ed ian co lifo rm limit of no m o re that 2 .2 MPN / 100 ml. Wh il e this wasn't a problem at low flow rates, o nce terti ary pla nt flows approached 50% of m aximum production, we starte d to regu larl y see so m e presumptives in th e range of 2 to 8 M P N total co li fo rms/1001111. It was found that m aintaining a residual chlo rine level of abo ut 8 mg/ I at the exit of the c hlo rin e co ntact tanks was necessary to

"" I

0 \\

RECYCLING

t II \\ a Ic r

â&#x20AC;˘R t-('~( lt- d \\ a l~r

3000

2000

1000

;

..,

1998

1999

1 . Outlines of the current usage pattern.

r ed u ce p r es umpti vcs and ac h ieve comp liance . Later as fl ows reached 75% producti o n leve l, IO m g/ I of chlo rine residual was shown to be effective. T he cause of the presumptivcs w as no t dete rmin ed wi th ce rtainty. Fo rtu nate ly, 1110,t did not confirm out as actual coli forms. H owever, it was speculated that the o pe n ch lo rine con tact bas in s we re allowin g dust from adj ace nt far ml and to settl e in the tanks. At the sa m e ti m e , growth of algae along the sides and bottom of the tanks we re observed. Interesti ngly, the co li fo rm level in the bottom tank sludge often exceeded 250 MPN. To he lp control algae and to preve nt dust fro m ente ring the syste m , tempo ra ry plastic cove rs were in stall ed ove r the ta n ks. Our turbidity limit was 2.0 NTU's . H owever, we fou nd that ave ragin g close to 1 NTU gave the best overall performance . Che m ical dosages were high the fi rst yea r of operation . Typically 40 to 50 mg/ I of alum and 6 to 9 mg/I of cation ic poly mer were needed to achieve I NTU perform an ce and th is also requ ired m o re frequent fi lter backwashes. Despite th e above proble m s, just over 6,200 ML of recycled water was produced during ca le ndar yea r 1998. M ore impo rtan tl y, we maintain ed 100% co mpliance w ith o ur pe rmit. 1999 Production issues Staff attacked bottlenecks that had previously limited produ ction, including checking the six filters. It was determined that they were working prope rly, but we fo und t hat the fil ter backwash returned to the secondary treatment pl ant w as upsettin g the tricklin g filt ers and t he seco nda ry clarifiers du e to its high chl o rin e residu al and solids loading T his flow stream was rerouted to the primary headwo rks w hic h soon resul ted in lower secon dary syste m turbid ities (5 to 7

~ ..

2000

;;

0

NTU's) and bet ter tertiary performance. P resum ptives contin ued to be a periodic problem but the confirmed va lu es were <2 cfu/100 1111. After a w hile , th ree strategies we r e u sed to m in i mize pr esu mpti ves . Fir st we m aintained chlo rine residuals at or just above lO mg/I. Second, it was found that prec hl o rinating the wa ter go in g to the filt ers was he lp ful. Finally, we noted t hat the so lids build- up on the botto m of the contact tanks wo uld n eed to b e re m oved eve ry four co six weeks. 1n all, just over 12,000 ML of water was produced in 1999.

2000 Production issues

O peratio nal issues declined in 2000. While co liform presu mptives occasio nally occurred, we focused o n m ax imi zing th e perfo rmance of th e seco ndary p lant w hi ch now routinely de li ve rs to us turbidi ties in the 3-5 NTU range. W e are i nsta lling pe rm a n en t cove rs fo r the c hlo rin e contact tanks and we plan to install an automatic sludge vac uum in t he tan ks. Based o n current producti on rates, we ho pe to produ ce about 13,000 M L of recycled wa ter for 2000. Pathogen monitoring

Path ogen mon itoring has shown tha t the plant continues to perform ve ry well. H owever, the coll ection and anal ys is o f pathoge ns is both ti me consumi ng an d expensive. Costs for a single set of ana lyses typically exceeds USS 1,000. Th e cou nty hea lth departm ent has suggested a quicker and more cost effect ive substitu te, clost ridium. This surrogate test has been now been used bi-weekly fo r the past two yea rs. T yp ica ll y, a five-log reductio n across th e treatm ent facility has been fo und. In those in stances w here the remova l is in the four-log range, th e health departmen t has attrib uted th is to periodic low levels of clostridium in the secondary syste m. Impact of high chlorine residuals

Because high levels of chlo ri ne are used in t he contact tanks, the res idual leavin g the storage pond is norma lly 4-6 m g/I. Initiall y we were concerned that this level mi ght cau se leaf b urn or other c ro p damage. Co n seque ntl y, a test was co ndu cted usin g ca uliflower seedli ngs. After a few weeks, it was determined that even a ch lo rin e resid ual of 15 mg/I did not cause an adverse impact. Other advantages of the high chl o rin e level in the po nd are that algae growth is reduced and WATER APR IL 2001

23


WATER

Table 1. Water Quality (mg/ L) Recycled

Well

375

TDS

825

Chloride

250

60

Sodium

185

50

4.7

SAR

TKN TP

1.8

30 2

the water continues to receive further disinfection.

Water Usage The project was design ed to supply water for about 4,800 H a of food crops. Based on about 490 111111 (4.9 ML/Ha) for th e irrigated area, abou t 23,000 ML of water would eventually be needed each year. However, most of th is water is supplied during the peak growing months of May through September. Since the recyclin g plant has a curre nt outpu t of nea rly 80 ML/ d (about 2,300 ML per month), supplem enta l well water is added to make up the diffe ren ce. 1n the winter m on ths , secondary eilluent is discharged to the sea.

Water Quality Table 1 compares the current chemical water quality of the irri gation waters. In a peak growing 111011th , Ju ly 2000, 2330 ML of recycled wa ter was added to 1520 ML of well water. Howeve r, the system was not designed to ac hieve uniform blending of the waters, so som e growers, depending on location and we ll usage, wou ld have to use more recycled water. On the clay or loam soils, most growers prefer a SAR of less than 3.0. Th e question of how high the salinity and SAR. can be ove r the lon g term witho ut signi ficant yield and soil permeability impacts is not known at this time. H owever, th e MWR.SA study in the 1980's did not indicate any soil salt build up problems despi te fi ve years of operation using unblended recycled water. T hu s, a multiyear soil salt monitoring program has been initiated to better understand this issue. Soil permeability proble ms due to excessive sodium ca n be improved by add ition of gypsu m. Salts ca n be reduced by membrane technology (e.g. reverse osmosis) . How ever, both of these measures have cost and other assoc iated impa cts. Because of this, the curre nt approach has foc used on reducing the salts added to the wastewater, mainly by water softeners. Big sa lt users in clude hospitals, comme rcial laundri es, food processmg

24

WATER AP RIL 2001

RECYCLING

indusnies, water soften ing companies, jails, coll eges, and major hotels. Our emphasis has been to request that these customers only use hi gh effi ciency demand type water softene rs and that th ey consider switching to potassium salt in place of sodiu m . T hus far, the voluntary response has been encouraging. Ou r calculations show that we sho uld be able to reduce sodium concentrations in our tertiary eillu ent from about 185 mg/ I to 150 mg/ I w ithin two years. W e have also started a reside ntial education program to use potassium salts. Fortunately, the plant eilluent contains very low levels of m etals and trace o rgan ics. As a resu lt, the growers have not expressed concern in this area. Our Source Control Division periodically samples and mon itors our commercial customers and outfall to make su re that we don' t receive incompatible poll utants. O n the residential side, we use billi ng inserts, sc hool presentations, and event booths as a way to e mphasize that hazardous and toxic wastes shouldn 't be dumped into the sewer.

impact of the water recycling will no t be verified until well water levels have b een measured fo r 5 to 10 years. However, computer m odels indicate that the project wi ll reduce seawater intrusion by 40 to 50 percent. Prelim inary well readings taken by MCWRA indicate that using recycled water is already maki ng an impact. Interestingly, the concern over water has encouraged and e mp hasized grower water management to the point th at the project uses about one-third less water now compared with historical water use j ust ten years ago . Although it took 20 years before the project became a reality, the MCWR..P has bee n a tremendo us success by providing a new source of water fo r the Salinas Valley. Persistence and ongoing dialogue w ith the custom ers (growers, regulatory agencies, and salt users) have proven to be the keys for negoti ating the ongoing obstacles expected for a large-scale and in novative project.

Operational Costs

Monterey R.egional Water Pollution Control Agency (MR WPC A) web page (growers sect ion) : MR.W PCA .org. Sheikh, 13. , Cooper, R.. & Israel, K. 1998. l-lr,~imir c11t1/11nrio11 4 rcrlni111cd water used to irr(~ntcji"'d rrops - A ras,â&#x20AC;˘ .w ,dy, Water Science & Technology. vol. -10, no. 4-5, pps. 261 267. Engin eering-Sc ience 1987. r:i11nl Report Mo11terey Wnsret11t1ter Rffln111ntio11 St11dy ji,r A)irim/r,1rc, Prepa red for Monterey Regional Water Pollution Control Agency, April 1987. She ikh, 13. , Cort, R. , Cooper, R.. & Jaques, 11..., 1998. "frrrinry- "f"t-rnrcd Rcrlni111ed Wnrer ji,r lrr(~nrio11 of Rnw-Cnic11 V<:~einbfrs, Chapter 17 of W astewater 11..cclamation and R e use, Edited by Asan o, T akashi , Phd, P E; Technomic Publishing Company, Inc ., Lancaster - Uascl. Sheikh, 13., Cort, R. P., Kirkpatrick, W.I<.; Jaques, R.S & Asano, T. 1990. Mo11terey 111nsrc111nter rerln111nrio11 st11dy for 11grirnlt11re, R.csearch Journal W l'CF, vol. 62, 110 . 3, pps. 216-226. Rosen blum , Eric; Sheikh, llahman; 1998. C /wosi11g to R c11se, Water Environment & T echnology, vol. 10, no. 5, pps. 75-78.

Th e combi n ed project operating budget is about US $6 million , ann ually. Of this, abo ut US $3.5 million is for direct ope rating costs with the balance for debt serv ice. for fiscal yea r 2000/200 1, recycled wate r produ cti o n was budgeted at 15,000 ML, well water proj ected at 6 ,900 ML , for a total of 2 1,900 ML. Overall, the long- term project cost is projected to be about US $ 160 per megalitre of water. This compares with typical grower well costs of US $40 to $60 per m egalitre . H oweve r, if seawater intrusion is not hal ted, the growers would either need to drill deeper wells or possibly find another water source. Either option would raise th eir costs beyond what they now pay.

The Final Product Despite the concern over sa lt levels in the longer term, the produce grown with recycl ed water h as bee n distributed without problems and th e quality has been excellent. W hile most growe rs prefer to keep their farm ing practices and results confidential, some have informally advised us that yields and quality are as good or better when using recycled water. Part of th is is likely attributable to the constant suppl y of nutri ents ava ilable in th e recycl ed water. T he mouth of the Va lley su ffers from abo ut 60,000 ML of water overdraft eac h year. As the amount of an nu al overdraft depends upon wea th e r conditions, the

Further Reading

The Author Keith Israel is th e General Manager of the Monte rey Regional Wate r Po lluti on Control Age ncy - Ca lifornia , U.S.A. email keith@ mrwpca.com . Prior to 1988 he held a simi lar positi on with the Victo r Val l ey Wast e water Reclamation Au thority. H e has been a board m em ber of th e WateReuse Association since its inception in 1990. H e is also a board mcm.ber o f the C alifornia Association of Sanitation Agencies.


The Portable meter with the specifications of a benchtop.

2 Year Warranty

Resolution - 0.01 NTU on low readings

Wide measuring range - 0.01 - 1,100 NTU

Automatic calibration using one to four points

Complies to ISO 7027 method for determination of turbidity

Supplied with four secondary standards and two empty cuvettes

Supporting you all the way

0

MERCK LabBusiness

207 Colchester Rd, Kilsyth Vic. 3137 Tel: (03) 9728 5855 Fax: (03) 9728 1351

Free Call: 1800 335 571 www.merck.com.au

A.C.N. oos 064 791


WATER

RECYCLING

ENDOCRINE DISRUPTING COMPOUNDS IN EFFLUENT REUSED IN AGRICULTURE R Lim, S Gale, C Doyle, B Lesjean, M Gibert Abstract A brief review is given on th e prese nce, fate and im pact o f EDCs in sewage efflu e nt reused in agricultu re on crop plants and livestock . Mammalian hormo nes and to a lesser ex tent some synthe tic che mi cals and me tals may po tentiall y pose so me risk to plants and animals. However, the re is a pa uc ity of st udies and the refore the precautio nary princip le shou ld unde rpin th e re use of se wage e fflu e nt in agric ulture, and the e ffectiveness of ST P treatme nts o n re moval of EDCs in reclaimed waters w arrants greate r attenti o n .

Introduction

h umans. D esp ite the diffe rin g view s in th e scie ntific co mmuni ty, concern s arc su ffic ie nt to wa rran t governme nts to revie w po lic ies towards ED C s, wh ich include amendments to legislatio n related to ED Cs, screening programs for EDCs, and d eve lopin g tes t pro ce d u r es . H oweve r, th e issue o f EDCs has rare ly been co nsidered with respect to effi ucnt re use in agriculture.

EDCs in Sewage Effluent T he con cen tra ti o ns o f ED Cs 111 treated cmu c nt depend on treatme nt technology of the STPs and the prcdo mi n ant constitue nts (do mesti c, industrial) of cffiucn t (T able 1). G en e ra ll y na tural a nd sy nthetic hormon es are prese nt in the nanogram/ litre range w hile alkyl phenols, Bisphcnol A and heavy m eta ls arc prese nt in the m ic rogram / litre range. T hese conce ntrations, howeve r, have been li nked to ED C e ffec ts o n w ildlife. Effects measured include abno rmal testes (Lye et al. 1997), fe minisatio n of male fis h Qobl ing et al. 1998), and reduction in gonopod ium le ngth (used fo r transfer of sperm packets) in m ale mosqu ito fish

(Barty and Li m 1999) . T he c o nce rn in t he re use o f e ffl ue nt is w hether these co ncentrati ons arc suffic ie nt to affec t agricultu ral p lan ts and anima ls. Fate of EDCs in the soil Afte r irrigatio n with effiu c nt t h e interaction of E D Cs w ith th e soil wou ld in part determ ine t heir even tua l tra nsfer to foo d fo r li vestoc k. Fe m a le h o r m o n es, th e organochlorinc pesticides, alkyl p henols, P CBs an d PC D D / Fs arc hydro phobic, and w ill adso rb on to so il particles b ut they arc m icrobio logically degraded u nd e r a e ro b ic co ndi tion s a t rat es depe nde nt on te m pe ra ture , so il c haracteristics and molecular we ights (IU PAC 1999).

E nd ocrin e d isrupti ng co m po unds (ED Cs) ca u se ad ve rse e ffects t o O rga nophosphatc pesticides (0 Ps) organism s and th eir progeny th ro ugh and carbamates, B isph c no l A and phth adirect in te rac t ion w it h hormo n e latcs are less hydrop ho bic. Phthalates are receptors of the target animal. T he interrapidly degraded by soil mi cro-organisms ac tion could be agon istic, w he re the un d e r ae rob ic co ndit io n s o r a rc ED C mimics a hormo ne, or antagonistic, vo latilised (N[tC 1996, Carri ngton et al. w he re th e ED C bl oc ks h o rm o ne 1998a). Howeve r, degradation produc ts binding sites thereby decreasing activity. ma y h a ve e nd oc ri n e di s rupt i n g M ore than 70,000 che micals arc believed properties sim ilar to o r mo re potent than to have e ndocrin e disruptive pote ntial th e p a re n t co m p o u n d. PC Bs a n d (Brad ley & Z a c h arews k i 1 998 ) . PC D D / Fs arc stable and th us G e n e ra ll y , hor m on e s arc pe rsist in soi l (Alco ck el al. several tho usa nd times more Table 1. Typical concentrations of some EDCs in treated 1995, M c l ac hl an el al. l 996). pote n t th a n indu s t r ia l sewage effluent. B isph c no l A biodegrad cs in so il c h e m ica ls, pes ti c ides and and with its low hydrophobicity Compound Secondary treatment Tertiary treatment metals (Khan & Ongcrth 2000, low potential to accumu late has Lim et al. 2000). Estrogen (ng/L) 38 3 in soil (Stap les et al. 1998). The impact of E D Cs o n 50 2 Testostrone (ng/L) H e a vy me ta l s c an a l so w ildlife such as fish , alligators 1.4 - 76 1.8- 3.6 Estrone (ng/L) accumulate bu t their bioava iland birds has been clearly 178-estradiol (ng/ L) <5 - 1 0 2. 7 - 6.3 abi li ty is infl ue nced by soil demonstrated. ED Cs have also c haracte ri stics (Feigin et al. <10 37 Estriol (ng/L) been linked to health and 1991 ). Ethyinylestradiol (ng/ L) <0.2 <0.2 r e p r o du c t i ve e ffec t s i n domestic ani mals e.g. abortions in sheep and cattle. C u rrentl y th ere is grea t deba te over the li n k betwee n e ndo c rin e disrupti ve effec ts in w ildli fe w ith t he adverse tre nds in the re pr o d uctive h e a l t h of

Nonyl-phenol (µg/L)

<0.02 - 330

Fate of EDCs in plants

2,4-dichlorophenol (µg/ L)

0.061 - 0.16

Alkylphenols (total) (µg/L)

27 - 98

E xcept for heavy m eta ls there is little researc h o n the effect on an d fa te o f ED C s in plants. Many o f th e ED Cs such as pesticides, PA H s, phthalatcs and PC Bs are not read ily taken up by plan ts (Tesoriero el al 1996, NR C 1996, A lcock et al. 1999). PC D D /Fs also arc no t rea dil y take n up by p lants

Bisphenol A (µg/ L) Arsenic (µg/L) Cadmium (µg/L) Lead (µg/L)

This is a very m uch edited version of the paper awarded the ' Best paper' at the R ecycling Conference.

26

WATER APRIL 2 00 1

0.02 - 0.05 1.3 - 23 <0.02 - 1 50 0 .1 - 44

Sources: Shore et al. 1993a, Desbrow et al. 1998, Lee & Peart 1998, Blackburn & Waldock 1 995, Rudel et al. 1 998 , Johns & Mcc onchie 1 995, Feigin et al. 199 1 , Bahri 1998.


WATER

due to their h ydrophobi city except by zucchini and squash (Mclachlan !'I nl. 1996) . H eavy m etals suc h as cad111iu111 and arseni c ca n accumulate in certa in plant types (R oss cl nl. 1991 ). Leafy vegetables tend to accumulate 111orc ca dmium than g rains and potatoes (IATP 1999). H owever, fol iar uptake of m e tals such as lead ca n occur and thus irrigatio n technique is im portant. Fate of EDCs in domestic animals As EDCs arc a rece nt topic of researc h, a 111ajo rity of tox icology tests pcrfor111 cd have been on labo ratory animals, and the re levance o f the ir responses co those of domestic an i111als, wildlife o r humans is debatable. Several countri es ha ve begun attempting to predict the fo tc of m an y EDCs in food c hains (e .g. M c lachlan cl nl. 1996, Alcoc k !'I nl. 1999) and their findings should be closely followed in the future.

Domesti c ani m als can ingest EDCs from agric ultural land irriga ted with sewage c muc nt via four pathways, eith er indirec tly fr o m consumption of plant material that bas tak e n up contaminants (c m u en t-soi 1/ a tmosp hcrc-pla n t-a 11 ima 1), consuming plant mate rial co ntaminated with emuent (cmuc nt- pl ant-a nimal), directly ingesting so il (c muc nt-soil a n i 111 a 1) , o r d r i n k i n g c ffl u e 11 t (c ffiu c nt-animal) . Th e ingestion of soil is considered the main exposure pathway fo r many EDCs ( NR.C , I 996), as plant uptake of many EDCs is in e fficient. Unde r Australian conditi o ns grazing animals commonl y ingest large amounts of soi l (R oss cl nl. 1991 ). le is estimated that a grazin g cow may in gest as much as 1100 pounds of soil annually (!AT P 1999). Contaminants bound co soil particles ca n dissoc iate in the gastroin testinal tract due to the acidi c co ndi tio ns, and arc e ith e r score d , metabolised o r excreted via urine o r milk fro m the an imal, o r directly excreted via fa eces . Keith (1997) Fries ( 1996) and IUPAC ( 1997 Alcock ct nl. (1999) Staples r l nl. 1998) (M c l ach lan , 1997) have a ll published work on the bioaccumulation and rate of exc retion of various organics but the disagreem ent be twee n the scudi es re quires furth er w o rk. H eavy m etals, especially cadmium, tend to accumulate in th e blood, live r and kidneys of animals due to th eir detox ifying role in the body, whereas muscle tissue and mi lk tend not to accu mulate heavy m e tals. Farm animals probably absorb < 5% of the cadm ium they in gest (Carring ton et nl. ¡1998b) .

RECYCLING

Lead conce ntrati o n s in organs of li vescock do not significantly in crease when exposed to elevated environmenta l lead (NRC, 1996) . This suggests that l:trge e n v iro nm e nta l d oses would probably be req uired to result in significa nt conce ntrations in animals. Effect of EDCs on plants and domestic animals

Dogra and Kaur ( 1994) state that EDCs can potentially disrupt the normal physiological functioning o f certain cro p species. Studies ha ve de mon strated th e stimulatory effects of ste roid ho rmo nes at certain concentratio n rnnges on plants but no sti111ulatory efft:cts at higher co nce ntrations. Shore cl nl. ( 1995) observed that alfalfa irrigated with sewage effluent, which co nta in ed steroidal estrogens from 111am111alia11 sources, had in creased phytoestrogcn levels which could potentially cause infertility in sheep and co w s . Adams( 1998), and Tho mas ( 1997) discuss exposure and effects. H ormon es arc naturall y found in domestic animals, and their e ffe cts arc dose dependent. Th e use of ste roid

impla nts on beef cattle shows that rdatively high d oses (20mg cstradiol) arc required to significantly lower pregnancy rates (H arg rove, 1994). Testostero ne levels of 200 ng/ g to >400 ng/ g in chicken litter fed to cattle have also been shown to affect reprodu ction (S hore ct nl. 1993b) . These results give some in d ica ti o n of the doses required fo r cndoc1inc d isruption. Whether li vestock on agri cu ltura l land irrigated w ith sewage cffiue nt could ingest these large doses is questionable and requires investigation. R.awlings el nl. ( 1998) acknowledged th at there is littl e in fo rmat ion on the potential fo r endoc rine disruption by pesticides in domestic animals. T hey, however, showed that by experimentally dosing ewes w ith a number of pestic ides c ndoc rino lo gica l effects were ind uced . These results suggest tha t over a long exposure period, pesti c ides cou ld signi ficantly reduce an animal's rep roductive ca pacity. Ca rri ngton er nl. ( 19986) found no sig nifi ca nt or detectable differences in di cldrin and other pest icides in cattle

WATER APR IL 2001

27


WATER

products, w hen animals were grazed on sludge amended land compared to control land. In contrast, Ross et al. (1991) reported that pesticide residues w ere deposited in animal fat and can be excreted in milk. N o nylphenol , th e main biodegradation product o f alkylphenols, does accumulate in seve ral aquatic species, including algae, fis h, ducks, mussels and crabs (IUPAC 1997 , Safe and Gaido 1998) but the endocrin e disruptive activity of their metabolites particularly o n domesti c anima ls is unknown. H owever, Safe and Gaido (1998) noted that p-nonyl phenol induces cell proliferatio n in human breast tumour M C F-7 cells, and is estrogen ic in mice and rats. H owever, it is 5000 times less potent than estradiol (Gaido et al. 1997). No pubhshed who le-body studies on the endocrine disruptive activity of many of the ED Cs in sewage effiuent on domestic an imals are avail able.

Conclusions and Recommendations EDCs in treated sewage effiuen t could potentially be of concern . N atural mammalian steroid ho rmones wou ld be of greater co ncern than the other co mpounds beca use of t heir hig h potency fo r endocrin e disru ption. The synthetic chemicals reviewed ha ve far less estrogeni c potency compared with hormo nes and, therefore, wo uld be of less concern The main exposure pathway of EDCs to animals is considered to be soil in ges ti on. Th e ir imp ac t thro u g h co nsumption o f fodde r should be m inimal as th eir uptake by plants is insignifica nt. Wheth er th e amounts so in ges te d wou ld ca u se e ndo c rin e disruption is unknown. Steroid horm o nes ca n also stimulate plant growth. They also elevate phytoestrogen content in plants such as alfal fa, w hich when fed to li vestock could possibly cause reproductive impairment. Wheth er o th er fodder crops would respond similarly to irrigation with eillue nt is unknown. The poten tial risk related to uptake of indi vidual EDCs by plants and animals, and th eir effects do not appear to be very significant if considered individually. H owever, sewage eilluenc ge ne rally co n ta ins a mix of th ese com pounds, which could additi vely impose endocrine disrupting effects or antagonistically cancel out th e effects o n th e target organisms. The relevan ce of 28

WATER APRIL 2001

RECYCLING

the additional exposure of plants and an imals to EDCs from eilluenc should also be assessed in th e context of existing inputs of pesticides, heavy metals from fert ilisers, natural and synth etic hormone s excreted by livestock, and atmospheric depositi on of co ntam in ants o n agricultural land. Relative to o ther issues related to reuse of sewage effiuent in agriculture suc h as risks due to pathogens, the risks d ue to ED Cs seem less. H oweve r, if irrigation is co ntinu ous, then the cumul ative build- up of EDCs may exacerbate any existing effect. For the present, given the poor state o f knowledge in this area, th e precautiona ry principle sho uld be invoked in eill uent reuse app lications. This could include operational and management strategies such as method of irrigation and w ithh oldin g effi uent to allow degradation of ED Cs before use. It is r ecom mended that resea r ch be continu ed along with regular literature reviews. This in formation will also assist the STP ind ustry to target th e removal of EDCs of most concern.

References Adams, N.R. 1998. Natural and anthropogenic environmental oestrogens: the scientific basis for risk assessment: Clover phytooestrogens in sheep in Western Australia. Pure and Applied Chemistry 70: 1855-1862 Alcock, R.E. , M cGrath , S.P. and Jones, K.C. 1995. The influence of multiple sewage sludge amendments on the PCB content of an agricultural soi l over time. E1111iro11111e11tal Toxicology a11d Chemistry 14: 553-560. Alcock, R.E ., Sweetman, A. and J ones, K.C. 1999. Assessment of organ ic contaminant fate in wastewater treatme nt plants. I: Selected compounds and physicochem ical properties. Chemospl,ere 38: 2247-2262. Bahri, A. 1998. Fertilizing value and polluting load of reclaimed water in T unisia. vllater R esearch 32(11 ): 3484-3489 Batcy, J. and Lim, R . 1999. M orphological and repro du ctive charac te risti cs of male mosquito fi sh (Gambusia affinis ho lbrooki) inhabiting sewage-contaminated waters in N ew South W ales, Australia. Archives of

E11viro11111e11tal Co11ta111i11atio11 a11d Toxicology 36:301-307 Blackburn, M .A. and W aldock, M .J. 1995. Concentrations of alkylphenols in rivers and estuaries in England and W ales. Water Research 29: 1623-1629. Bradley, E.G. and Zacharewski, T.R. 1998 Exoestrogcns: mechanisms of action and strategies for identification and assessment. Environ. Toxicol. Contam . 17: 49-57. Carrington, E.G. , Davis, R .D., Hall, J.E., Pike, E .B., Smith, S.R. and Unwin , R.J 1998a.

Revie,u of the Scie11tijic Evidence R elatit\~ to the Co11trols 011 the A,~ric11/t11ral use of Sewa,~e Slud,ee. Part 2 - Evidence since 1989 R elevant to Controls on the Agricultural

use of Sewage Sludge. WRc report No DETR 4454/ 4 . WRc , M edmenham, Marlow. pp 227. Carrington , E.G., Davis, R.D. and Pi ke, E.B. 1998b. Review of the Scie11tijic Evidmce

Relatill,l! to the Co11trols 011 the A,l!riwltural 11se Sludge. Part 1 - The Evidence

of Sewa,~e

Underlying the 1989 Department of the Environment Code of Prac ti ce for Agricultural Use of Sludge and the Sludge (Use in Agricu lture) R egulations. WRc rep ort No DETR 4415 / 3. WRc, Medme nham, M arlow. pp 109. Desbrow, C., R outledge, E.J., 13righty, G.C., Sumpter, J.P. and Waldock, M. 1998. Identification of estrogenic chem icals in STW effiucnt. 1. Chemical fractionation and in vitro chemical scree11i11,~. E1111iro11111e11tal Scieuce a11d Tec/111oloJ1y 32: 1549-1558. Dogra, R.. and Kaur, A. 1994. Effect of steroids on some growth and biochemical parameters of Tritiw111 aestivu111 L durin g germination. Crop Research 8: 611 -620. Fcigin, A., R avina, I. and Shalhevet, 1991.

trn;~ntio11 wit/, Trea ted Sewage EJ/111C11t: Mm,a,~ement for E11viro11111e11tal Protectiou. Volume 17 in Advanced Series in Agricultural Sciences, B. Yaron, E. Bresler, G .W. Thomas and L.D. Van Vleck eds. Springer Verlag, Berlin: 98 Fries, 1996. Ingestion of sludge appli ed organic chemicals by animals. '/1,e Scie11ce of the 'J"otal E11viro11me111 185: 93-108 . Gaido, K.W. , Leonard, L.S. and Lovell , S. 1997. Evaluation of c hemi cals with endocrine modulating activity in a yeastbased steroid hormone receptor gene t ranscription assay. "foxicolo,~y a11d Applied Phar111ncolo,ey 143 : 205-212. Hargrove, D.D. 1994. Use of growth promotants in replacement heifers. In: Factors A.ffecti11,e Cn!f Crops. M.J. Fields and R.S. Sand eds. Chapter 6. CRC Press, Boca Raton: 91-104. !ATP (Institute fo r Agriculture and Trade Policy) 1999. S1w1iee Sludge atl!I Food

Sefety. http://www.iatp.org/edrc/library/adm in/u ploadedfiles/Scwagc_Sludge_Food_Safcty. htm . Accessed 7/ 1/00. IU PAC 1999. Draft Report: E11docri11e Disruptiâ&#x20AC;˘rs i11 the E11viro11111e11t. Project 660/26/97. IU PAC, D ivision of Chem istry and the Enviromm:nt - DCE Water and Soil Commission . pp 28 . Jobling, S., Nolan, M., Tyler, C. R., 13righty, G. and Sumpter, J.P. 1998. Widespread sexual d isruption in wild fis h. E1111iro11111e11tal Scie11ce a11d Tec/111010,~y 32:2498-2506. J o hns, G.G. and McConchie, D .M. 1994 . Irrigation ofbananas with secondary treated sewage cffiuent. 11. Effect on plant nutrients, additional elem ents and pesticide residues in plants, soil and leachate using drainage lysimeters. A 11stmlia11 a11d A,eriwlt1m1I Research 45:1 601-1617 Keith, L.H. 1997 . E11viro11111e11tal E11docri11e Disn1ptors: A Ha11dbook of Property Data. John W iley and Sons, N ew York. pp 1232. Khan, S. and Ongerth, J. 2000. H ormonally active agents in domestic wastewater T reatment - A literature review. R eport prepared for CGE Australia. 48 pgs.


WATER

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Lee, H. and Peart, T.E. 1998. Determination of '17(-estradiol and its m,::tabolites in sewage effi uent by solid-phase extraction and gas chromatography/mass spectrometry. Jo11mal of A OAC flltematio11al 8 1 :1209-1216. Lim , R .. , Gale, S., and D oyle. C. 2000. Review of the endocri ne disrupting potential of sewage effiuent reused in agriculture. R eport prepared for CGE Australia. 45 pgs. Lye, C. M. , Frid, C. L. , Gill, M.E. and McCormic, D. 1997. Abnormalities in the reproductive health of flounder Platichthys flesus exposed to effiuent from a sewage treatment works. 1\llari11e Pol/11tio11 B11lleti11 34:34-41. Mclachlan, M.S. 1997. A simple model to predict accumulation of P CDD/ Fs in an agricultural food chain . Clte111ospltere 34: 1263-1276. Mc l achlan, M.S. , Horstmann, M. and Hinkel, M . 1996. Polychlorinated d ibenzo-p-dioxins and dibenzofurans in sewage sludge: sources and fate followi ng sludge applicatio n to land. 71,e Scimce cif rite Total E1wiro11111e11t 185: I 09-·123. N l'l..C (National l'l..esearch Council) 1996. Use of R eclaimed Water a11d S/11r(~e i11 Food Crop Prod11ctio11. National Academy Press, Washington D. C. pp. 178. Preziosi, P . 1998. Nat ural and anthropogenic environmental oestrogens: th<: scientific basis for risk assessment: Endocrine disruptors as environmental signalers: an introduct ion. P ure and Applied Chemistry 70- 161 7-163 1. ll..awlings, N .C., Cook, S.J. and Waldbillig, D. I 998. Effects of the pesticides carbofuran , ch lorpyrifos, dimethoate, linda ne, triallate, trifluralin , 2,4-1), and pentachlorophenol on the metabolic endocrine an d reproduct ive endocrin e syst<:111 in <:wcs.jo,mial qf Toxicolo,ey a11d C11viro11111e111a/ J-fraltlt Part A 54: 2 1-36. R oss, A. D. , Lawrie, ll...A, W hatmuff, M .S., l< eneally, J.P. and Awad , A.S. 1991. C11ideli11es.fi,r rite 11se of Siwa,ee Sl11r(ee 011 Agrimlt11ral Lc111d. L. Sim ed. Third Edition. N SW Agriculture, Sydney. pp 17. l'l..u dcl, R .A., Melly, S.J ., Geno, P. W., Su11, G. and 13rody, J. G. ( 1998). Id entification of alkylpheno ls and other cstrogenic phenolic compounds in wastewater, scptage, and groun dwater on Cape Cod . Massachusetts. E1wiro11111e1llal ScimcC' (I{{(/ Tec/1110/0,ey 32: 861-869. Safe. S. H. and Gaido, I(. 1998. Phytoestrogcns and an thropogenic <:Strogenic compounds. E1111iro111111•11tal 7i1xicolo,ey mid Clte111istry 17: I 19- 126. Shore, L.S .. Gurevitz, M and Shernesh. M (1993a) . Estrogen as an environmental pollutant. B11lll'fi11 ,if E11viro11111e11tnl C1m/a111i11atio11 (1{1(/ 7i,xicolon 51: 361-366. Shore , L.S., Hard- M arkowitz, E.. Gurevich , M . and Shemesh, M. 19936. Factors affecting the conc<:ntratio n of testosterone in pou ltry litter. Dlllim11111c11tal Sric11cc a11d /-lea/ti, A28: 1737- 1749. Shore, L.S., l< apu l11 ik, Y., Gurevich , M. , Win inger, S., Uadam y, H and Shcrnesh, M. 1995. Induction of phytoestrogen production in 1\lfrdica,Qo sati11a leaves by irrigation with sewage water. E1wiro111111•11tal mid Experi111mta/ /3otm1y 35: 363-369. Sonnenschein, C. and Soto, A.M. (1998). An updated n:view ofcnvironlllental estrogen and androgen m imics and antagonists.Jo11nw/ qf Steroid BiNltcmistry a11d Molewlar Biolo.~y 65: 143-150. Stapks, C.A., Dorn, P.U, l< lecka, G.M. , O'l31ock. S.T. and f-farri s, L.R. 1998 . A review of the environmental fa te, effects, and exposures of Uisphe nol A. Cl,c111ospl,m• 36: 2149-2173. Tesoriero. L., C resswell , G ., Sarooshi, R. and Fahy. P. I 996 . Va/11e ,if

Co111posted Biosolids as a Soil Co11ditio11er mid Fertiliz er i11 tltc Prod1wio11 of V~ectablcs. S/11d,gc Applicmio11 Progm111s, Proj.:ct 7 Final l'l..eport. NSW Agriculture Organic Waste Recycling Unit and Sydney Water. pp16. Thomas,J.A 1997. Phytoestrogens and hormonal modulation: A minireview. E1111iro11111c11tal mid N11tri1io11al fllteraaio11s. I: 5-12.

The Authors Richard Lim, Sharyn Gale and Christopher Doyle are at th e D epartmen t of E n vironme ntal Sc iences, Unive rsity of Technology, Sydn ey, (e mail: R .Lim@ uts.edu.au). Boris Lesjean is with CG E Australia, Sydney, and Michel Gibert works for Vivendi Water, Fra nce.


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RECYCLING

WATER RECYCLING IN SYDNEY: THE OPTIONS A Gregory Abstract Sydney Wate r Co rporation recentl y developed its twe nty-year strategic plan for water recycling. An integrated resource plan ning methodology was used , evalu ating a range of recycling opti ons in co mpari son with op tion s fo r w ater effici ency and leakage reduc tion to meet future water supply needs and reduce effiu ent discha rges to waterways. For the situation in Sydney, it was concl uded that im plementi ng de mand management options wou ld ach ieve greater wate r conservation, di scharge redu ctio n and gree nhouse e m ission redu ctio n benefits over the next twen ty yea rs at a lower cost to the co mmun ity than recycling opti o ns (;1part from som e major industrial recycl in g sc hem es).

This paper d iscusses the methodology used to deve lop a recycling strategy for Sydney and draws con clusio ns about integratin g wate r cycle plann ing.

Introduction Sydn ey Water C orporation's Operating Licence includes requ irem ents to reduce per capita water demand by 35'¼, o ver the period 199 1- 20 I I. T he Sydney kllatcr Act requires the corporation to adop t an ' ultimate aim ' of el iminati ng dry weather disc harges to waterways. Inc reasing th e am o u nt of recycling is o ne strategic optio n to reduce potable con sumption and/or cffi uenc discharges . Im provin g e nd - use water effic iency or increasing on-site reuse by customers, and red uc ing lea kage in water su pp ly syste ms are alternati ve strategic op tio ns tha t can

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be pursued to achieve the sa me objectives. In order to establish strategic direction fo r water cycle manage ment that wou ld meet the Corporatio n 's regulatory requi rcm en ts, Sydney Water adopte d a n integrated resource managem ent methodo logy to develop a Wate r R ecycling Strategy in parall e l with its Demand Management Strategy. Sydney Wate r e ngaged the Institute fo r Sustainable Futures, UTS, to assist in the development of these strategies .

Current Water Recycling C urrently, approxi mate ly 30 rn cgalitres pe r day (ML/d) of effiuent is recycled fro m Sydney W ater's ·t 2 ocean and 19 inland sewage treatm ent plan ts (ST Ps). Th is re prese nts 2.5'¼, o f the 1,200 M Lid o f wastewater treated at STPs and 1.9% of the total 1,600 ML/d of water used in Sydn ey W ater's supp ly area. 83% of t his recycl ing occurs within STPs, th ei r potable water use havin g been reduced by 50% si n ce 199+/95 . The re arc te n recycling schemes to customers for eith er industrial o r irriga ti o n purposes and it is estimated tha t between 15 a nd 20 M L/ d of water is recycled on-s ite at industrial and co mme rcial fac iliti es ( 1). Sydney Water has seve ral recyclin g initiatives planned. These include a maj or 20 ML/ d indu st rial sch e m e at Po rt Kemb la , a demand managem ent program targeting water efficiency and on-site recycl ing in ind ustry , R ouse H ill dua l reti culation sc he me, su pply of sewage to the WR.AMS sche me at 1-lomebush Ba y, two urban irrigati on sche mes, and th ree rural irrigati o n proj ects as part of new village sewe rage sc he m es. Thcse projects arc expected to double th e level of recyclin g ove r th e next te n years.

Strategic Drivers for Additional Water Recycling Th e key factors conside red in deve lo pi ng t h e water recycli n g strategy included: • Th e need for additional wate r supplies over the plan nin g h orizo n • Progress cowards th e 'ultimate aim' o f zero dry weather discharge of sewage e ffiue11t co waterways

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• Com muni ry expectations for water recycling • E conomic dcsirabi liry of water recycli ng from a comm unity cost perspective • En vironmen tal adva ntages/ disadvantages of w ater recycling Future Wat er Needs

Since the ea rly I 980's Sydney has been experie nc ing a downward trend in pe r ca pita water consumpti on . This has occurred due to pricin g refo rm , th e introduction of water efficie nt devices like dual flush toilets a nd efficie nt sh owers, co mmunity response to co nse rvati on ca m pa igns, red ucti ons in industrial and comm ercia l sec tor demands, a nd urban co n solidation strategics changin g the reside ntial ho using mix. In addition to this trend , Sydn ey Water's 2000-2005 Operating Licence sets targets to red uce consumption from the 1990/ 9 1 usage of 506 litres per capita per day (led) to 329 led by 20 I I, a 35% redu ction. A s o f Septe mber 1999, per cap ita co n sumpti on was 4 15 led, an 18% red u ct io n , and plann ed ini tiati ves should achi eve the further 17% by 20 11. Acco untin g for fo rec;ist popu lation growth of abou t 0.7 millio n people and redu ced per ca pita cons umption , overall wate r demand is projected to decrease by 12% over the nex t 20 yea rs. C urre nt forecasts indi cate that Sydney w ill ha ve suffi cient water supplies for at least the next 40 yea rs. Effluent Discharge Reductions Sydney W ate r 's Act req uires the adoption of an ultimate ai m of e liminating dry weather effluent di sc harges to waterways. R educed water consumpti o n w ill h ave the net effect of reducin g per cap i t a wastewater di sc h a rges from custo m ers by 34% over the period from 1991 to 2021. As a result, it is esti mated that em uc nr discharges to waterways during dry we;1ther should be red uced by approx imately 20'Yc, over the same period. Th is wi ll be co mpl emented by Sydn ey Wate r 's S700M program to red u ce sewerage system infiltration over the next 20 years (estimated to ac hieve approximate ly an additional 15% reduction in dry weath er fl ows). Th ese reductions will co ntribute substant ia ll y toward the "ultim ate aim" of zero di~charge during dry weather. Community Expectations

In 1995 and 1999, Syd ney Wate r carried our research of the comm uni ty attitudes to water recyc ling. The 1995 research (in a drought period) concluded, "th e co mmunity will accept water recyc lin g, nor beca use it is inherently

RECYCLING

good, bur because it is an inevitable initi ati ve, w hic h along with o th er initi atives will safeguard Sydney's future water supply. Associated with the accepta nce of water recycl in g is considerable concern about its health and safety, particularly when usin g it fo r persona l purposes."(2). Th at concl usion ho lds fi ve years later, in 1999, with a slight decrease in suppo rt for recyc ling, like ly to be due to a general belief in the community that t he need to conserve water diminishes during periods of rain. It may also be associated w ith co mmunity pe rcepti o ns fo llowi ng the 1998 water conta mination incident. (3). Sydney Water has also co nducted ex te nsive co mmun ity consultatio n in relation to wastewater treatment plant upgrad es and oth er wastewater projects. When give n rhe c ho ice between water recycl in g o r discharge to a waterway, the loca l community has generall y expressed a preference fo r recycl in g. Government Water Reforms

Fo r Sydney Water, the water reform package is not a direct drive r to undertake more recycling. H owever, progression of ini tiatives such as water resou rce pricing reforn1 , government funding o r incentives,

or stakeholder agreement on the use of cm uen t for envi ronme ntal flows, coul d provide the enabl ing mechanisms to faci li tate further increases in wate r recycling. Strategic Summary With in the twenty year p lanning horizon there is no need for additional wa ter supplies in Sydney Water's area of operations but substantial progress will be made towa rd reducing discharges to waterways. C ustomer's expectations of water recycling arc predominantly based on the perception that it will be needed for water supply. However, on a project level they wi ll c hoose water recycli ng when faced w ith this alternative versus discharging cmue nt to a wate rway.

Options To Increase Water Recycling Taki ng the above strategic influences into account, Sydney Water assessed 17 water recycling options against a range of water effic iency and leakage reduction optio ns. Options were selected as be ing the " best case" or optimal co nditions sce nario of each type of recycling in a particular

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31


WATER

market. The best case ana lysis was used to screen whether further investigation into particular options was watTantcd . The selected options arc based on actual schemes investigated by Sydney Wate r or case studies prepared specifically fo r the strntcgy ana lysis. All options assumed that product quality w ill m eet the appropriate national or state recycled water guidelin es for the particular end use involved. Non-Drinking Water Recycling Options

Non-potable options were se lected to cover a broad range of recyclin g possibilities across different market segme nts. Th ese ranged from large regional reti culated schem es to greywa te r recycling w ithin an ind ividua l customer property. Industrial & Commercial M arkets

Potential demand from major indust1·ial customers in Syd ney is estimated to be approximately 70-80 ML/d. T h ese customers include paper manufacture, steel production, oil re fin eries, an d proposed co-generation power plants. Because potential demand from general industry and comme rcial customers is considerably less and tends to be d ispersed geographically, it is fa r more difficult to establish viable supply sc he mes from

RECYCLING

STPs than for major industry. For these customers the most likely viable recycling option is on-site recycling. Five industrial and commercial recycled water options were eval uated: • l,1d11strinl recydi11,{! lo n 111njor process i11d11stry - 20 ML/ d of mi cro-fi ltered (M F) and reverse osmosis (RO) treated tcrtia1y STP cm u en t and a 3 km distribution pipe line. • 011-site 1wyclil1,{! 11,itl,i,, n co111111ercinl ln1111dry - MF/ partial R O treatment of laundry process wastewater recycled via the ex isting industrial water supply system. • 011-site 111nste111n/er recydi,,,'< i11 n11 existi11,(! I 000 st11de11t sc/100/ - assumes all wastewater is treated and recycled to ma in amenity areas for urinal and toi let flushing. • Crey111nter recycli11,{! i11 n 11ew 200 s11ite, 10 storey /10/el - G reywater recyc lin g (MF & ultraviolet (UV) disinfection) for toilet and urin al flushing, and air condition ing cool in g tower make-up water. • Crey111n/er recycli11g i11 n 11ew J,ig!, rise c!(Jicc b11ildi11.f! - Similar to the hotel option, w ithin a new 25-storey office building with a typical floor area of 1000111 2 . Rural Irrigation Markets

Sydney Water's market research ind icates that there is sufficient high value

agriculture in western Sydney to use most of Sydney's inland STP effiucnt flows (4) . T h is highly seasonal demand ranges between 13 ML/d and 170 ML/d, with an esti mated average of 80 M Lid. Most demand is currently met by riparian extraction for betwee n S1-S35 / Ml, compared to $900/Ml to purchase potable water. In the Illawarra region sou th of Sydney, dairying is the domina nt agricultural industry, w ith seasonal irrigation demand rangi ng from 0 ML/ d to 3 1 ML/ d and an average demand of '17 ML/d. Two regional agricultural irrigation options were evaluated based on prclimi nary scheme designs costed by Department of Agriculture and Department of Pub lic Works & Services: • Ric/1111011d Wi11dsor Sclre111c - a 23 ML/d scheme for the irrigation of c itrus, dairy and turf farms, supplied with tertiary treated and disillfcctcd cffiuent from St Marys and North Ri ch m ond STPs. • D11rnl Srlre111e - Similar to the Richmond Scheme, this is a 3.6 ML/ d scheme to irrigate orchards, nurseries and cut flowers w ith disinfected tertiary effiucnt from Castle H ill STP. Urban Irrigation M arkets

High quality tertiary treated recycled water co uld be provi ded from in land ST P's for urban irrigation. Sewer mining is the most likely option in the large coasta l catchments as supply from the major prima1y coastal STPs is generally not feasible. Two 'best case' go lf course irrigation options were evaluated: • Co!{ w11rse irr({!ntio11 s11pplied fro111 a S"J 'P - supply of te rtia ry STP effiuent via a I .2 km p ipeline via a consta nt pressure supply-on-demand pu mped system to existing on-site irrigation systems suita ble for recycled water. • Co!{ co11rse irr(l!nlio,, s11pplied.fro111 n "se111cr 111i11ir1,(!" plnrrl - A major sewer runs through the go lf cou rse, above grou nd at the extraction point, en abling easy access to constan tly adequate sewage flows. Prescrccning, biological seconda ry treatment and disinfection. Ex istin g storage and irrigation systems arc suitable. Residential Markets Non-potable water use (toilet flushing and garden use) in the res idential sector accounts for approximately 14% of current total water demand. Expected new urban growth ove r the next IO years w ill generate approximatel y an add itional 2.7 ML/ d of non-potable residential demand eac h yea r, equal to a 0 .2% annual increase in total demand (5). The best recycling

32

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potential in chis sector is fo r dual reticulation in greenfield develop m L·nt areas or 011-site greyvvater recycl ing in new ho using. Five recycled water options were eva luated in the residential sector: • Dual rerirnlated supply i11 a ,r.1rec·1!field l,ousi11,f! estate - a dual reti culation system in a 1500 lot greenfield subdivision, similar in concept to the R.ouse H ill scheme. Includes additional nmrient rem ova l, MF, chlorine disinfection, storage, and gravity reticulation. • Crcy11,ater recycli11g i11 a 11e11, si11glc d111c/li11,e - recyc li ng laundry and bathroom greywacer for to ilet fl ushi ng and external use, treatment by a package domestic greywater system. • Crey111ater systc111 i11 11e111 ho111c• u11its - A M F & UV greywacer recycli ng system for two adjoining new home unit developments with a tota l of 9 1 units. Treated greywater wou ld be used in all units fo r toilet flushing, as well as outdoor uses. • Crcy11,ater systc111 i11 a 11c111 hi,eh-rise npnrt111e11t to11Jer - MF & UV greywate r recycling syste111 fo r toilet flushing in a new 25 storey single tower of 150 apartme nts. • New npart111c11ts .rnpplied.fm111 rl,e proposed Li,,crpool to 1\lfa/a/,ar reuse pipeli11c - a 15 storey block of 120 apa rt111ents su pplied w ith disin fected tertiary treated effiuen t fro m the pipeline 1 km away for toil et flush ing and outdoor use. Drinking Water Recycling Options

T hree potable recycling options were evaluated in the analysis as potential futu re options: • Dirco Potable Rccycli11,f! by /ll(accpti11,e Orem, STP F/0111s - the establishment of 18 distributed STPs to intercept all 920 ML/d of average dry weather sewage flows to the three ex istin g major coastal STPs. Foll owing trea tm ent losses, 734 M L/ d of potable qua li ty cffi uent wou ld be recycled co the existing drin ki ng water distri bution system at the nearest suitable rese rvoir or water 111ain (45% of total average dai ly de mand). • /11-dircrr P<>rable Recycli11,f! cf lula11d TP F/0111s - T his option proposes treating all cffiuent fro m the ex isting inln nd STPs to potable quality and recycling to Wa rraga111ba Dam. Approximately 180 ML/d wou ld be recycled. Treatment costs incl uded arc those above the cost of achieving effiucnt quality requ ired fo r river discharge (ie 0.3 mg/ I of total phosphorus). • D irect Pora/Jle Rccycli11,11 <f /11/a11d STP F/o111s - Similar to the indirect option except water would be recycled to the Warragamba water deli very pipeline upstrea111 of Prospect Water Fi ltration Pbnt. 158 ML/d of potable water would be recycled.

Option Evaluation The options were analysed using economic and cnviron111enca l criteria. T he eval uation assumed that other issues concern ing public health and the environmellt would be manageable on a project by p rnject basis. Economic Evaluation

Sydney Water's experie nce ove r the last fi ve years has shown that the major constraint co market development of water recycling projects is their generally poor economic viability. For the strategy to be rea listic it was important to u nderstand how the various recyc ling options compared econom ically to each ocher, as well as to current water supplies and alternative water efficiency options. Lease-cost planning was used for the economic analysis. This method calc u laces the cost to the com mu n ity of the different optio ns available to Sydney Water. "Cost to the community" is the total unit cost of the option without consideration of how im plemencio n and opera ting coses would be recovered.

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Senior Engineer Capital Projects • Industry-leading Authority with ochallenges • Career opportunity with regional lifestyle benefits • $65,000 negotiable package plus

commuter vehicle Baiwon Water is the largest non-metropolitan water authority in Victoria, employing 350 people. It is an acknowledged industry leader providing water and sewerage services to a permanent population of 250,000 people covering more than 8,100 square kilometres. Geelong has the benefit of being Victoria's second largest city yet offers a regional lifestyle only minutes from the Surf Coast and is very accessible to Melbourne. Water consumption of 38,000 megalitres, assets worth $800 million and a Capital Works program of over $200 million ensure ongoing exciting and diverse engineering challenges that range from headworks to customers' taps and beyond. Working closely with the Branch Manager, you will take complete responsibility for all aspects of project management, engineering design and staff management of up to 10 engineering staff working on around 30 projects valued up to $5 million. Projects include: investigation, design, construction commissioning and hand-over of new, rehabilitated or upgraded facilities, spanning water and sewerage treatment plants, pump stations, main sewers, water basins and tanks, water supply and sewerage schemes. Construction works are normally completed by contract while investigation and design are completed using a mix a consultant and in-house resources. To be successful in this exciting career role, you will be a qualified civil engineer, possessing significant experience in the water industry. Project management, design experience and a sound knowledge of contracts standards and conditions will be important. An accomplished leader and manager, your effective communication skills will ensure an ability to motivate as well as present at all levels. Your demonstrated technical ability will enable you to positively influence the engineering excellence of the Authority. Apply in confidence to Brian Cooper via e-mail on swa@swacorp.com.au (Word format), quoting reference 756 in the e-mail subject line. Acknowledgment will be automatic. Alternatively, phone on (03) 9525 0066, fax to (03) 9525 0088 or mail your detailed resume.

Least Cost Planning Analysis

The lease cost plan ni ng analysis compares the levcl ised cost of WATER APR IL 2001

33


WATER

RECYCLING

Recycle d Water Options Ranking

$12.00 $10.00

l

~ $6.00

a le-.etised unit cost

($/kl )

II Net le-.elised cost (benefit) 1 ($/kl )

$8.00 1

, _ _•_Ne _ t_le_-.e _ l_ised _

co_s~ _(ben.::.e.::. fit::.. ) .::. 2~($/k :::...:.:l::.. ) _ . t - - - - - --

-

-

-;

... $4.00 $2.00

Figure 1. Recycled Water Option Rankings Recyc led Water Supply Energy Consun-pton

• Greenhouse Gas from Transfer Iii Greenhouse Gas from Treatment

Figure 2. Greenhouse Impacts of Recycling Options

all optio ns (ie. no t just water recycling) to satisfy the need for water service. includin g increasing supply (such as fro m storages, water recyclin g, gro undwater sources, and rai nwater tanks) and reducing de mand (increased water use effi c iency) . In additio n to leveliscd costs, be nefi ts are also analysed, in the fo rm of a levcliscd net cos t or net be nefit (depend ing whether th e bene fits arc greater or less than t h e cos ts) . Includ in g se p arate level iscd ben efits allo ws a co mparison o f the impac t of d iffere nt categories of be n efi ts o n the ove rall cost- effec tiveness of eac h opti o n. For p u rposes of chis analysis th e fo llow in g d efin itions an d ass umptio ns w here used in the least-cost plann ing analysis (6). Levelised Cost T h e unit cost of wate r, lcvclised over th e period of consideration , taking into accoun t all capital and operating expenditure of Sydney Water or customers, and the am o unt o f w ate r saved or supp lied . It is defi ned as: L

= PV (costs to SWC) + PV (cos rs ro msro111crs) P V (111arcr sm,cd or SIIJ!Jllird)

w here: L = lc11cfised rns r i11 Sl/.iL 34

WATER APRIL 2001

P V(w srs)

= prrsm r 110/11c cf wsrs (S) ,11,cr a gi1m1

JJrriod a11d a ,f!i11e11 m r/ disw11111 rate (30 )1Ctlrs a11d 7% IISCd) f) V(r,,atcr

sm1ed or SIIJIJJ!frd)

= fll'CSCllt

11a/11c o(

r/11' 1/larcr ocr11ally SIIJIJ!licd by a s<>11rcc or sa11cd h)' a dc11rn11d side or 111<1/l'I' 1:{lirii'II[)' <>prio11 011cr rl,<' sm11r JICl'iod 1111d 11si11,f! tl,c sm11c disw11111 rate

(/.i L)

N et levelised cost (be nefit) 1 The cost m inus th e levcliscd nee be n efi t d ue to: • the avoided marginal cos t o f pu mping wate r, 0 11 a Sydney w ide average basis ($33/ M L) • the avoided margin al cost of treating water, based on the variable charge by th e m a in 1300 o p e r ato r ( P ro s pe c t ) ($55/ML). • the avo ided margina l cost of futu re augme ntation, ie a res id ual m arginal capacity cost (S-10/ ML). • the avo ided m arginal c ost o f sewage pumpin g ($20/ M L) . N et leveli sed cost (benefit) 2 Th e cost, inc luding the be ne fi ts listed above, m inus th e levcl iscd benefits of: • th e avo ided margina l ca pac ity cost and avoided STP operating costs of upgrading STPs. T h is m ea ns the be nefits that arise fro m redu cing t he ca pacity of key


WATER

RECYCLING

Demond Management & Recycled Water Option Ranking s $3.50

c Levelised cost ($/kl)

s

f

1 I

IJ Net levellsed cost (benefit) 1

• Net levelised cost (benefit) 2

S3.00

Water Recycling for Demand Management

$2.50 $2,00

Figure 3 shows the entire range of o ptio ns considered by Sydn ey W ate r in the develo pment o f dem and manage m ent program co meer t he 35% reduccion in dema nd requ ired unde r Sydn ey Water's operati ng lice nce.

$1.50

~

§

S1.00

lI

so~o

!l

$0.00

Figure 3. Water Cycle Option Rankings

co mpo ne nts of a STP as a result of reduced hydrauli c lo ad. Th ese results arc inferred fro m the Illaw arra LC P Study ( 130/ML). • the avoided capacity cost of upg rading trunk mains and reservoirs as a result of re du ced wa ter demand (S 130/ML) . • th e a vo id ed cost asso c iated with in creased pumpin g from T aUowa scorage during d ro ught, based o n data provide d by the Sydn ey C atchme nt Authority ($20/ ML). Some o f the abo ve ben e fits app ly only co w ate r e ffi c ie ncy o ptio ns and were included in th e analysis to eva lu ate wa ter recyc ling o ptions against other demand 111anagc 111c nt 111casures. Economic Ranking of Options

Th e le vcliscd costs a nd bene fits o f the recyclin g water o pt io ns are shown in Fig ure I. The o ptio ns arc ranked re lati ve to leve liscd cost. Optio ns that cost less th an S0.20/ kL (variable cost of po table supply) and rt·pla ce c urre nt potable wate r use arc t·co no111i ca lly viab le without furth e r analysis and should be pursued. As can be see n in Figure I , the re are currentl y no re cyc lin g optio ns that mee t bo th these rcquire 111c nts. T he lowest cost o ptio ns arc agri cultural and urban irri ga ti o n but th ese gen erall y do n't repla ce po table de mand o r alternati ve low cost water supplies arc available to customers. Ove r t im e, the va riable cost of wa ter suppli es is lik e ly to inc rease du e to su ch facco rs as in crease d wate r treatm e nt require m e nts and environme ntal flo w require me nts. This could chan ge th e viability of som e recycle d w ate r o pti o ns. Environmental Evaluation Th e e n vironm e ntal anal ysis use d gree nh o use gas emissio ns as a surroga te fo r indica ti ve e n vironm ental impa ct.

d istribution (pu mp ing) based on ene rgy use . T he analysis takes in to accou nt energy savings fro m reduced dri nki ng water co nsu mption .

The recycled wate r o p tio ns analysed ge nerally result in addi t io nal e ne rgy consumpti o n (over current water supplies) because o f additio nal treat m e nt or wa te r transfe r requirem ents. Figure 2 translates energy consumption in to kilo g ra m s of gree nhou se gas pro du ced per kilo litre of recycled w ate r for eac h recycled water o ptio n. Fo r each optio n th e anal ysis apporti o ns th e g ree nho use gas producti o n to trea tm e nt and

T he selecced de 111and m anagement progra111 pred o m inantly targets wa ter effic ie ncy and leakage con tro l m easures . T h e key excep tion is m ajo r industrial recyc ling, two proj ects of t his type be ing included in t he c urrent progra m. T hese proj ects in pa rticula r have an added adva ntage of ach ieving immediate, permanent, and easi ly q uantified wa ter dem and red uctio n gains. Th ey offer the least risk of all the water conservation optio ns in th at t he o utcom es arc certain. The conserva ti o n o utcom es of ocher opti o ns have higher levels of uncertai nty and could rake considerably longer periods of tim e co ac hieve expected results.

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WATER APRIL 2001

35


WATER

Summary of Findings The least cost planning analysis of recycling options demonstrates that in general, it is m ore cost effecti ve and environmentally sound for the community to reduce th e dema nd fo r water in preference to recycling water. Sydney Water would need to recycle approximately 240 ML/d to achieve sim ilar reductions in effluent discharges as wil.l be achi eved through demand reduction over th e next twenty yea rs, at a substantially higher cost to the comm unity. While the eco nom ic viability of recy c led wat er sc h emes wi ll vary depending on individu al circum stances, in Sydney the least cost forms of recycling are generally large industrial recycl ing prop osa ls, o n -s it e in dustria l and commercial, agricultu ra l irrigation, and selected u rban irrigation. Non-potable recyclin g of any type in the residential sector is very costly, even in h igh-density housing. Broad scale implementation of water conservati on initi atives in th is sector is far mo re effective from a least cost and environmental p erspecti ve. However, as the residential sector demands about 67% of

RECYCLING

total water supply, resea rch and development of longer term recycling options in this sector needs to be explored further. R ecycling effiuent for agricu ltural irrigation in western Sydney ca n potentia lly provide a reliable, low cost wate r supply as an alternative to ri ver wate r extraction from the Hawkesbury/ N epean R.iver. Over the next 20 years th is could also lessen the environmental impact from increasing effiu ent discharges due to urban growth. However, this can only be achieved if stake holder agreem ent is reached on river management and riparian extractio n issues and some or all of the capital cost of infrastructure can ultimately be subsidised by th e community. The viabiliry of irrigating urban open space w ith recycled water is very si tespecific but worth pursuing where it is comm erciall y feasible for customers and Sydney Water. Because there is no need fo r addi tional water supplies within th e plan ni ng ho rizon , the only reasons to consider potable recycling wou ld be to accelerate progress towards the ultimate aim of zero dry weather efflu ent discharges, or when potable recycling becomes cost-com pet-

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WATER APRI L 2001

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icive w ith ex1st111g water suppl ies. To sign ificantly reduce ocean discharge by potable recycling would requ ire exp enditure of approximately $3 billion and annual operating expendi tures o f Sl SOM, compa red to a 20% d ischarge reduction over 30 years fro m water conserva tion. Other considerations include commun ity and regulator oppos ition to potabl e recycling, increased awareness and un certainty about the potential hea lth impacts of chernica l and pathogens in wastewater, increased treatm ent energy requirements, and technological advancements in alternative water supplies such as desalination.

Implications for Planning The end results of reduced water usage and effluent d ischa rges can be ach ieved through both water conserva tion o r recycli ng initiatives. The ana lysis shows that for Sydney Water at this point in time, pu rsuing water efficiency is bette r from bo th an e n vi ronmenta l and economic perspective. Howeve r, over time, changes in technology, the cost of potable water suppli es, customer response to demand management programs and other facto rs wi ll influe nce the amount of recyclin g pu rsued. For other water authoriti es, the need for additional water supplies beyond what can realistica ll y be ac hi eved throu gh demand management ma y positi o n recycl ing more h ighly as a water cycle managem ent opti o n. T he challenge for water authorities is to present a balan ced and informed perspective on the role of recycling to the community. Of particu lar importance is to inc rease co mmuni ty understand ing of how their use of water impacts on ou r environment and influences decisi o ns about future water cycle management.

The Author Alan Gregory is Manager , Water Co nservation & Recycling at Sydney Water Corporation . PO Box A53 Sydney South, NSW 1232. Ema il alan.gregory@ sydneywa ter.com .au

References 1. Sydney Wata Pricing 13ranch survcy of 111ajor custo111ers, 1997 & Group Product & Asset Planning phone survey, 1997. 2 Sydney Water Corporation, 1996, Co1111111111ity Views 011 Wnter Reuse, R.esearch Report. 3 Sydney Water Corporation, 1999, Co1111111111ity Views 011 Wnter Recydit(~, Research Report. 4 Agsol, 1999, Wesrer11 Syd11ey Awiwlt11rnl

Markets. 5. End use analysis, Institute for Sustainable Futures, 1998, Syd11ey Wnter Lenst Cost Pln1111i1(~ St11dy, Phase 1. 6 . Institute for Sustainable Futures, 1998, Syd11q1 Water Least Cost Plmmi1(~ St11dy, Phase 1.


a

WATER

LIMNOLOGY OF THREE RESERVOIRS: MACROPHYTES AND CYANOBACTERIAL BLOOMS A C Joglekar, D Al Bakri, M Chowdhury Abstract

Introduction

Nuisance cyanobacterial blooms are Water quality of the c ity of Orange now a regular occurren ce in the inl and wate r supply catc hme nt in ce ntral west waterways and wa ter bodies of Australia New South Wales has been studied (Do nn ell y et al. 1996) and arc poten tial during th e last three yea rs to understand hea lth risks to hum ans, li vestock and causes and develop management strategics other o rganisms (Perry and Vande rkl e in fo r th e contro l of cya nobacte ri al blooms 1996). They arc prevalent durin g hot in the catchm ent reservoi rs. The three Au strali an summers, whereby th e sta ti c reservo irs vary in their depth at fu ll water bod ies create d w ith t h e capacity: Sm in G oslin g C reek, IOm in impoundment of watercourses, become Sprin g C reek and 30111 in Suma Park. the rm all y and di ssolved-oxygen stratifi ed While the deeper and larger Suma Park (W ebste r et al. 1997). Often the limit set reservoir suffe rs serious cyanobacte rial by N ew South Wales Blue-G reen Algae b loo m durin g summ e r, the othe r two T ask Force ( 1992) of 2,000 cya nobacsha llowe r rese rvo irs do not ex hibit tcrial cells/m l in drinking water supplies signifi ca nt cyanobacte ria l o utbrea ks. The becomes difficu lt for catchment managers ai m of this paper is to identify limitin g t o meet. T o effective ly man age factors and processes respon sible for this cyanobacterial blo oms in a partic ular va riati on . All th ree reservoirs become catc hment, the cause and effect relationthermally and dissolved-oxygen stratified shi ps between ph ys ico-c h e mi ca l or du rin g summe r resulting in almost bi o logical factors and their occu rre nce anoxic conditi ons at the bottom. Unlike need to be understood . the two shall o wer reservoirs, hi ghe r T he O range water suppl y catc hm e nt concentrations of nitrogen (N) and in New South Wales encompasses th ree phosphorus (P) were found nea r th e r ese r vo irs . Suma Pa rk reservo i r bottom sediments of Su ma Park reservoir (max imum depth 30 111), w hi ch is the during stratifi catio n. H igher water temperawrc during the summer months appeared to play an imp ortant role in the o n set of cyanobacteri al ~~¡ I blooms in th e deepest .....~.t .... , r ese r voi r. The possible i diurna l mixing in shallower reservoirs and the dense growth of a r oo t ed subm c rgc nt ma c rop h ytc, Vallisn cria gigantea, could be the key fac to rs co ntrollin g cya n obaccer ial grow th. Impli ca tions of th ese ma crophytes on cyanobac te ria and Craek rela ted biomanipulation in Waterbody Cetchmerl Boundery in land water bodies me ri t further investi ga tion.

~ ~"/

Keywords: W ate r quality; cyanobacteria; nunient loads; reservo irs; stratification

-

Figure 1 . Orange Water Supply Catchment

ma in water supply fo r the city, has been expe ri encing toxic cya n obacte ri a l (A nabaena an d M icrocystis) blooms of cou nts reaching to more than 50,000 cells/ml at the off-take poi nts. In contrast, S pr ing C reek reservoir (maximum depth 1Om) has counts of no t more than 7,000 cells/ ml of cyanobacteria w hi lst Gosl in g C ree k reservo ir (maximum depth Sm) has not experienced any cyanobacteri al outbreak (O range Filtratio n Plan t, '1999). R esu lts of water quality monito1ing of these three inland reservoirs are d iscussed in th is paper. The paper aims to compare the limnological cha racteristi cs of th e three rese rvoirs and determin e the factors t ha t arc causing variations in cyanobaccerial b looms amo ng t he th ree rese rvoirs.

Materials and Methods The study on the lim nology of Su ma Park reservoi r was done fro m January co D ecember 1997 (C howdhu ry and Al Bakri 2000) whi lst chat of Spring Creek an d Gosling Creek reservoi rs were done from May 1998 co June 1999. Profile measure m ents o f te mp erature, p l-I , d issolved oxygen (DO) and electrica l conducA civicy were taken fortnightly "'' at every one meter interva l from the Sprin g C reek and Gosling C reek rese rvoirs using a ca librated I--l ydrolab D acasonde mulcip r obe. Water samp les we re also collected fo r the analyses of total suspended solids (TSS), tu rbi dity, coral ph osphorus (TP ) , filcrable reactive phosphorus (FR P, sample fi ltered t h rough 0.45um membrane fi lt er), t ota l nitrogen (TN), nitraten i trogen (NN, samp l e fi lte re d t h rough 0 .45um 111 e 111 b r a n e f i I ce r) an d cya n o b acteria l co u ncs . Samples were analysed in the WATER APRIL 2001

37


WATER

Un i vers i ty of Syd n ey/ Ora nge ca mpus laboratory imm ediately after coll ection. Concentrations ofTP, FRP, TN and NN in th e 1997 sa mples were determined t hrou g h H AC H m ethods (HAC H , 1992) w hile the rest of th e ana lyses were don e u sin g st andard m e th od s (A PH A, 1986) . T en percent of the analyses were subjected to quality control ch ecks at oth e r water laboratori es including NAT A-certified co mm e rcial laboratories and were fou nd to have less than I 0% coeffi c ient of va riation (CV) . Profile data o n TN and TP from M arc h to Jul y of 1997 and TN of Septem ber 1997, were unava ilabl e for S um a P ar k r ese r voi r. Corre la tion - regression analyses were done on ce rtain parameters and cyano bacterial co unts using Genstat5. Su b m e rge n t ma c rop h y tes predo minant in Spring C reek and Gosling C reek rese rvoirs were ide ntified and the ir ex tent of co ve ra ge was estimated fro m fi eld o bse rvation s and w ith th e use of bathymetric m aps.

14 .00

o

12.00

· · + · · Spnng Creek

5 10.00

-

I::

~

c!

A.

--0--Suma Park

Goshng Creek

400 2.00

0.00 Jan

Feb

Mar

AP'

May

Jun

Jul

Aug

Sep

Ma-

/lfX

May

Jun

Jul

Aug

Sep

Oc1

Nov

Dec

12.00

i

g

j

10.00 8.00

600 400 2.00

0.00 Jan

Feb

OCI

Nov

Dec

4 000

I

3500

i

3000

2500

C.

is 63 km 2 and the reservoir has a su rface area of I . ·1 km 2 at full su pply level. Gosli n g C r ee k reservo ir was con structed 111 1890 as th e fi r st muni cipal wate r supp ly system w ith a 6-+5 M L sto rage ca paci ty, surface a re a of 0.2 km 2 an d max imum depth of5m at full supply level. Apart from being a reserve water supply, th e Orange City Cou ncil is o pe ning th e rese rvoir to the publi c for recrea tional purposes.

Results Suma Park Reservoir Limnology. Th ermal

strati fication in Suma Park rese1voir was evident fro m ,.soo spring (Scpte mbe r) to late 1.000 s umm e r ( F e bru a r y) . osoo I . T e m pcrature differential 0.000 • Jan Fob Mar Apr May Jun Jul Aug between top to botto m Sop Oct Nov Doc was abou t -+-8°C at th e p ea k of th e stratified 0. period and d ropped to near zero during w inte r m o nth s when there was complete mi xin g (Fig.2) . An a e r ato r wa s i n o p eration during th ese m o nth s. wh i c h m ay Ap, May .kll Sep Aug Oct Catchment Description ex pl a in t he n a r row Th e O r a n ge Wat e r temperature d iffere nce. Figure 2. Limnological dat a for Suma Park, Spring Creek and Stratifi cation o f dissolvedSu pply Catchment, w hich Gosling Creek reservoirs. A. Temperature difference between covers an area of ·179 km 2, oxygen con ce ntrations in surface and bottom; B. Bottom dissolved oxygen (DO) includes the thre e reservo irs concentration ; C. Total nitrogen (TN) concentration differential; and the water column sta rted and feede r c reeks , is situated in October - a month after D. Total phosphorus (TP) concentration differential to demonstrate to th e so uth and south east o f stratification and presence of bottom sediment nutrient fl ux. thermal stratifi ca tio n was establi she d. T his w as al so the city's urban area (Fig. 1). cha r ac t e r ise d b y low It is part of t h e u pp e r minor to m o derate erosio n , severe bottom DO, nea rin g anox ia (0 .1 3- 0 .62 catchme nt system of the M acquari e strea m ban k an d gull y erosion affect 6.2 m g / L) and hig h hypo limnctic nutri ent Ri ver, w hic h is o ne of the main wate r km of the drainage syste m. sources of Murray-Darling Basin. T he co ncen tratio ns. T he nutri ent re lease T he Su ma Park rese rvoir, built in presu mably from the bottom sedime nts catchm ent is predominan tly o f basa lti c 1962, is located o n the upper reaches of led to a conce ntration diffe re ntial o f 0.5 soi ls with native, naturalised o r improved Summer H ill C reek, approxi111ately -+ km to 3.6 mg/ L TN and 0.03 to 0.3 m g / L pasture (77%) . Other land uses arc east o f Ora nge. Th e reservo ir has a TP (Fig. 2). Cya nobacteria l popu lation c ro pping ( 12%), hortic ulture (7%), surface area of 1.3 k111 2 , m ax imum depth tim ber (2%), softwood plan tation (1 %) ra nged fro 111 -+,000 to 12 ,000 ce lls/ m L of 30111 and storage capac ity of 18,073 between Novembe r to March . A sh ift and a small (0. 1%) mining and populated M L at full supply leve l. fi-0111 predom inantl y A11abae11a during th e area (D LW C 1996) . R.ain fa ll is eve nly low- flow and hotter period to ,\firrocystis distributed throughout th e year w ith an Sprin g C ree k rese rvoi r is locate d at du ring th e colder spe ll w as noti ceab le annual m ean of 946.5 111111 , m o nthl y the junction of Sprin g C ree k and (Fig. 3). T here was, howeve r, n o ranges o f 55-73 111111 during the drier Gos ling C reek. It was completed in indication of in creasin g conce ntrations period (February- Ap ril) and 8 1- 102 1931 , was raised in 19-+7 and was recon of bio-available nitrogen and phospho rus 111111 durin g the w ette r m onths Qu lyst ru cte d in 1969 foll owin g partia l in su rface w ater during peri ods o f stratOctober) (Bureau of M eteoro logy 1996). e mbank111 c nt fai lure in 1966. Th e ifi cati o n (Fi g. ~)- Although Suma Park The soil erosion map of Ora nge (DLWC rese rvoir has a stora gc capacity of reservoir was the 111ost tu rbid and w ith 1996) showed that althou gh less than -+ ,500 M L and m axi mu m depth of I Om th e h ig h est total dissol ved sol ids 15% of the catc hm e nt appears to have at ful l suppl y le vel. The catc h111 ent area 38

WATER APR IL 2001

~

f

2.000

1

·•······


WATER

(electri ca l co ndu ctivity, (TSS) and T P among the Anabaena EC= 155 uS/c m) among three reservoi rs stud ied 14,000 the three reservoirs (Table I}. Apart from a - - 0 - -suma 12,000 stu died (Tabl e I), its o few cell counts durin :, · · + · ·spring 10,000 wa ter was quite clea r the su mm er months, thl' --4•-- Gosling (turbidity = 4 NTU) in 8,000 reservoir is almost devoid th e b eg inning of the of cya nobacteria. The 6,000 summer months. Positi ve same submergent macro4,000 corre lations were found ph yte, Va /lis11cria ,<?('.!a111ea, 2,000 between cyanobac te rial found in Spri ng Creek -co unt s and ce rtain reservoi r also covered 0 Jan Fob Mar Apr May Jun Jul Aug Sap Ocl Nov Dec physico-chemical facto rs: approximately 40% of temperature (r=0 .807), Goslin g Creek reservoi r. EC (r=0 .574 ), TN Figure 3. Total cyanobacterial counts (cells/ml ) with dominant genera Discussion (r=0.454), NN (r=0.42 1), marked. T P (r=0 . 15 6), Tur b H igh nutrie nt levels analyses showed pos1t1ve relationships (r=0.299), su rface and bottom FRP especially ph osphorus, low fl ow cond ibetwee n cyanoba cterial co unts and the concentratio n d ifferentia l (r=0.504), tio ns, degraded aquati c ecosystems, TP diffe rential (r=0.364) and TN differfo ll ow i n g parameters: turbidit y availa ble li ght and warm temperatures (r =0.36 7), NN (r =0 .2 9 5), FRP e nti al (r=0.543) . ha ve been identified as the m ost (r=0.283), surface and bottom J=RP important factors influenc ing cya nobacSpring Cre ek Reservoir Limn o logy. co ncentration diffe rentia l (r=0.63 1) , teria l growth (13lue-Gree n Algae Task Thermal stratification was evidem in this T P differential (r=0.470), TN differe ntial Fo rce 1992, 1-b rris 1994) . Fo r a bloom rese rvoir from N ovember to March with (r=0.443), NN differential (r=0.247) and temperature differentia l fr om top to to occur, a fuctor or a confl uence of temperature differential (r=0.21 I) . factors may be acting on the system . In bo ttom of 6. 7- 11 .0°C. The reservoir Gos li ng C r eek Reservoi r bottom during this peri od was almost in the case of Suma Park rese rvoir, the Lim no logy. Stratification for both anoxia with DO rang in g from 0. 14 to increase in te mpe ratu re during t he temperature and D O in this reservo ir 0.40 mg/ L. H owever, diffen:nces in summ e r month s appeared to have fo llow the sa me patterns as that of Spring nu trient concentrations between surface trigge red the ou tbreak o f cya nobacteria Creek rese rvo ir. The re was also no and botto m were not obviously higher as refl ected by a high co rrelatio n coefliduring these summ er m onths co mpared distinct pattern of bottom sedimen t cie n t (r =0.807) . This was also in nutrie nt release despite the occ urre nce to the winter months . The latter pe riod conjunction w ith th ermal and dissolved of stratification. Concentrations of biois ch a ra cterised by coral 111ixing of the oxygen stratification and increased available nutrie nts in surf.1ce water at water column and with well-oxygenated hypo li m netic nutrient co nce ntrat ions certa in periods of the yea r also correbo ttom e n vironment. Similarl y. th e w hereby d iffere ntia ls from surface to sponded w ith that of Spring Creek bio-available nutrients (fi lte rable reacti ve bottom wate rs showed positive correreservoir (Fig.3) . G osl ing C reek reservoir phosphorus, FRY and nitrate nitrogen, lations w it h cya nobacteria. T hese NN) in surface water were found lowe r had the hi ghest tota l suspended solids conditions were exace rbated by low during the s umm er surfa ce water turbidity 111011ths and in increased and hi gh p H (8. 1-9.5) . co ncentrations during Clearer su rfa ce waters 1 600 1 A. the winter and rain y - o - - Suma Park g ive cya n o bacte ria a •. -• .• Spring Creek per i od from Ma yco mpe titive adva ntage 1.200 t - - Gosiong Creek O c tober (Fig .3). Spring ove r ot h e r p h ytoC reek reservo ir had the plan kton beca use of th eir z 0 800 hi ghest mean TN and flota t ion abilities d' z NN co n ce ntr at i o n s overco min g the 0 400 among the three rese rseparatio n between light vo irs ( Tab l e I ). 0.000 and nu trients in a water Jan Feb Mar Apr May Jun Jul Aug Sep Ocl Nov Dec Cya noba c terial co unts body during strati fi e d were minimal , with period s ( Verhoeven above 1,000 ce lls/ ml 1993) . Duri ng th ese occ urring o nl y in 0.050 B. wa rm er periods, they February. Most of th e can st ill access the 0.040 reservoir sh o re~ and h y p o limn io n 's b io0.030 embankments of up to ava ila b lc phosphoru s Cl. 2-m deep, were heav il y o therwise limited in the a: 0.020 u. vegetated (approximately ep ilimnio n because of 0.010 30'¼, of total reservoir i ncreased pri m ary 0.000 a rea) by ribbo nw eed productivity. With the Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec (Vallis11cria ,S!i,ea111ea), a absence of mi xi ng, the submergent ma crophyte o t h er ph y toplankton nati ve t o Australia. Figure 4 . Monthly concentrations of A. Nitrate-nitrogen (NN) and B. sink s to the bottom R esu lts of corre lati o n Filterable reactive phosphorus (FRP) in the three Orange reservoirs. (M itrovic 1997, Webster

...

i

i

WATER APRIL 2001

39


WATER

et al. 1997). Although an ai r-injec ted pump was install ed in th e Suma Park reservoir in summe r, it evidently was not suffici e nt to m ix the e ntire water column as reflected by the still relatively high te mperature differential between top and bottom. Th e high p H in the water column is due to carbon dioxide stripping because of enhanced photosyntheti c activity. Boers (1991) fou nd that phosphate release rates from the lake sedim ents in creased sign ifi cantly with inc reasing p H. This nutrient then becomes available for in creased cyanobacterial growth. In Suma Park reservoir, these were present in concentrations above 0.020 mgP/ L (mean su r£ice wate r FRP) and 0.052 m gP/ L (mean surface TP). Based on Martin et al. ( 1995), the reservoi r has a hi gh potential for algal growth since TP co ncentrations are above 0 .035 mg/ L, the level at which they observed to have triggered eucrophicacion. Increases in TP to greate r than 0.050 mg/ L due to e nhan ced primary productivity and conseq uent decomposition , wi ll likely lead to problems suc h as deoxyge nation of th e bottom water (G ibso n 1998) . AN Z ECC ( 1992) suggests that the dissolved reactive phosphorus concentrations should be about 0.0 15-0.030 mg/ L o r below to min imise th e gro wth of algae in Au stralian rivers and streams. H owever, according to Steinbe rg and Hartmann (1988), as little as 0.0 IO mg/ L of total phosphorus is sufficient to promote cya nobacceria growth in th e presence of favourable physical conditions such as lac k of turbulen ce. A mass ba lance of the sedim ents and nutrie nts contained in the reservoir showed that except fo r NN , Suma Park reservo ir acted as a trap fo r all these compone nts (C howdhury and Al Bakri 2000). Since it is evident th;n in ternal loading is happening durin g summer months in low- flow conditions, there is

a reason co bel ieve that the reservoi r has a constant supply of nutrie nts readily available for cyanobacterial growth and conseque ntly fo r the bloom to occ u r in s uit ab l e cl im at i c c onditi ons . Cyanobacterial blooms triggered by elevated water tempera tu res, increased so lar radiation, low-flow and calme r condjtions has also been observed in two Queensland reservoirs (W ebste r et al. 1997, Jon es and Poplawski 1998) . This also fa vo ured th e dominanc e of A11abae11a. Both Sprin g C ree k and Gosling reservoirs also experienced the rmal and DO stratifi cation because of the warm er temperature, prolonged daylight and low- flow conditions during summ er. Th e TN concentration was slightl y h igher at the bottom of th e reservo irs during th is perio d compared to the coole r m onths. Except for December, TP did not va ry in concentratio n througho ut the water colu mn . It is possible that th e re cou ld be a diurnal mixing in the wate r co lumn du ring th e cooler summer ni ghts. T he bioavailable nutrie nts (FRP and NN) of th e shall ow reservoirs' surface waters appeared to be in lower conce ntrations during the low- flo w summe r mo nths and higher during the cooler, high- flo w cond itions in winter. This cou ld be du e to the increased photosynthesis durin g sum mer and spring, w hi ch exerts a P de mand greater than th e rate of suppl y such that the solubl e P concentratio n drops as th e uptake by phytoplankton in creases (Gibson 1998). NN must have been utilised in the sam e manner. The relatively minor increase in cy anobact e ria durin g su mm e r , appeared to have been related to nuc1icnt releases fro m bottom se diments during months of stratification. H owever, sin ce th is did not result to al gal blooms at alerting levels, phytoplankton productivity may have been regulated by th e

growth of other flora suc h as 1/allirnl'ria gi,~a11tea, a rooted submcrgent macrophyte found abundant in th e two shallow reservoirs. The differences between the deep reservo ir (Suma Park) and the two shallower o nes (Sp ring Cree k an d Gosling C reek) w hich cou ld have influe n ced th e pr ese n ce o r lack of cya nobacterial blooms, are cwo main facto rs. One factor is th e diurnal mixin g potentially happening in the two shalJow reservoirs. When the stratifica tion is diurnal , that is when it is establ ished and destroyed on a diurnal cycle, co mplete mixing of the water column every night will be unfavourabl e for cyanobacterial popu lation grow th (Bornians et al. 1997). Upo n destratifi ca tio n, the alga l population is being spread to the deeper layers, w hi ch in effec t reduces growth due to bght limitation. The second factor is the predominance of Val/is11eria gi,~a11tea in the two shallow reservoirs. Val/is11eria, alon g with other aquati c macrophytes, ha ve been fou nd to out-compete algae and cyanobacteria fo r phosphate in the wate r co lumn (Scars and C onli n 1996) . Being attached o r rooted, ma crophytes like 1/al/irneria, have access to both sediment and open water suppli es and can therefore compete effi ciently with th e algae (Rattray ct al. 1991 ). The waters in both the shallow reservoirs had also high transparencies o f 1.67111 to 1.7 1m deep allowing Vallis11cria to thrive withou t light limitatio n.

Conclusion All three Ora nge rese rvo irs arc situated in the sa me geology, su1Tou nded by similar land use, exposed to th e sam e cl ima tic conditi o ns and mirror each other in terms of da ytime th e rmal and djssolved oxygen stra tification. However, Spring C reek and Gosling C reek reservoi rs did not experience cyanoba cterial blooms as severe as that in the deepest

Table 1 . Mean values of the physico-chemical variables and cyanobacteri a counts in surface water during the study period s. pH

EC 11S/ cm

S.dlsc transparency m

Turbidity NTU

TSS mg/L

TN mg/ L

N03-N mg/L

TP mg/L

FRP mg/L

Cyanobacteria cells/ ml

Suma Park (30m)

7.8 ±0.2

155.0 ±3.0

1.45* ±0.10

7.3 ±2.2

5.1 ±1.1

0.927 ±0.084

0.188 ±0.034

0.052 ±0.007

0.020 ±0.003

3,175 ±1080

Spring Creek (10m)

7.8 ±0 .2

61.0 ±5.0

1.71 ±0.05

6.7 ±1.7

3.9 ±0.7

1.101 ±0.138

0.322 ±0.107

0.058 ±0.009

0.011 ±0 .003

470 ±130

Gosling Creek (5m)

7.4 ±0.2

50.0 ±4.0

1.67 ±0.09

7.0 ±1.2

5.4 ±1. 0

0.950 ±0.034

0.296 ±0.114

0.077 ±0.015

0.013 ±0 .003

14 ±6

Reservoir (max. de pth)

*1999, 2000 data

40

WATER APR IL 2001


reservoir, Suma Park. The presence of a prolific, rooted submergent macrophytc, Va!li.rncria g(_fa11tca and the possibility of diurnal mixing happening in the sh,lllower reservoirs could have implications on cyanobacterial growth. Efficient mixing of water column and manipulating the ecology of reservoirs are therefore potentially effective management options to control chronic cyanobacterial bloom. Applicability of such strategies for deeper reservoirs such as Suma Park needs to be investigated.

References ANZECC (!992) Australian Water Quality Guidelines for Fresh and Marine Water, Australian and Nt·w Zealand Environment and Conservation Council, Melbourne. APHA (19%) Standard Methods for The Examination of Water and Wnstewater, 19th ed., American Public Health Associntion, Washington, D.C. Blue-Green A!gat· Task Force ( 1992) l3lueGrcen Algae, Final Report of the Task Force, NSW Department of Water Rt'sources, Sydney. 13onnans M, llurch M, llaker P, and G Jones (1997) Modelling the Dynamics of l3lueGrcen Algae In Relation to River Flow. Final Report to LWRRDC. 10 pp. Bureau of Meteorology ( ! 9%) Listing of dnily and monthly r:1infoll and temperature for Orange AP, llureau of Meteorology, New South Wales Regional Office, Sydney, 2 l March J 9% (unpublished). Cl10\vdhury M and D Al Bnkri (2000) Limnolo!::,>y of Suma Park reservoir - an inland water body. Proct'edings of the Xth World Water Congress, 12-17 March 2000, Melbourne. DLWC (19%) GIS of Orange, Statistics for Orange Water Supply C.ttchment, 10 May !996, Department of Land ,md Water Conservation, Orange, NSW, (unpublished). Donnelly T, Olley J .M, Murray A, Caitcheon G, Olive L and P Wallbrink (1996) Phosphorus and alga! blooms in Australian Catchment~. Proceedinbri; of the Conference "Downstream Effects of Land Use", eds: Eyles, l-lunter and Raymond, Rockhampton, April 1995. QDPI (in press). Gibson CE ([998) The dy11amics of phosphorus in freshwater and marine environments. In: Tunney H and O T Carton (eds) Phosphorus Loss from Soil to Water. pp. 119-135. HACH (1992) Water Analyses Handbook, 2nd ed., HACH Company, Colorado, USA. Harris G P ( ! 994) Nutrient Loadings and Alga! Blooms in Australinn waters - A Discussion Paper. Occasional paper No. 12/94. LWRRJ)C. 99 pp. Jones G J and W Poplawski (1998) Understnnding and management of cyanobacterial blooms in sub-tropical reservoirs of Queensland, Austrnlia. Wat. Sci. Tech. 37(2):161-168.

Martin V, Bowling Land G Robinson (1995) ChaflCy C:1tchment Nutrient Study, Public document, report no. TS 95.173 of tht· Technical Seivices Directorate, Department of Land and Water Conservation, November 1995, 57 pp. Mitrovic S ( 1997) What Scum Is That? Algal Blooms and Other Similar Prolific Plant Growth. DLWC. 24 pp. Orange- Filtrntion PJ;mt {1999) Database on cyanobacterial counts in Suma Park and Spring Creek reservoirs. Personal communication. Perry J and E Vanderklein (1996) Watc-r Quality: Management of a Natural Resource-, Blnckwdl Science, Cambridge, Massacht1Setts, USA. Rattray MR, Howard-Williams C andj MA Brown ( 1991) Sediment and water ;IS sourcc-s of nitrogen and phosphorus for submerged rooted aquatic macrophytes. Aquatic llotany, 40:225-237. Sears P L and K C Conlin (1996) Control of Algae in Planted Aquaria. http:// www.thek!'ib.com/J)lants/Fert!izer/searsconlin.html Steinberg C E Wand 1-1 M J-lnrtmann (1988) Planktonic bloom-forming Cyanobacteria nnd the eutrophic.1tion of lakes and rivers. Freshwater lliology, 20: 279-287. Verhoeven] (1993) lmp!enwntation of the New South Wales Alga! Manngc-mem Stratq.,,y,

Australian Journal of Soil and Water Conservation, 6(3):30-34. Wc-bster !,Jones G, Oliver R, Bonrnms Mand 13 Sherman (I 997) Control strategies for cynnobacterial blooms in weir pools .. In: Davis, JR. (c-d) Managing Algal Blooms: Outcomes from CSIRO's Multi-divisional blue-green nlgal program. pp. 51-66.

Acknowledgments The project has been funded by the Australian Research Council (ARC), Orange City Council, Department of Land and Water Conservation (DLWC) and National Heritage Trust (NHT) and National Landcare Program.

The Authors Alma C Joglekar is a PhD student (email: ajogleka@orangc.usyd.edu.au). Dr Dhia Al Bakri is a senior lecturer in Environmental Management at the Faculty of Rural Management, (email: albakri@orange.usyd.edu.au). Mosharef H Chowdhury is a PhD student, all at the University of Sydney, Orange, PO 13ox 883, Orange NSW 2800, fax (02) 6360 5590.

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B

WATER

TRANSPORT OF PATHOGENS THROUGH SANDY SOILS: EFFECT OF WATER QUALITY J K Rawlinson, R S G Toze Abstract Th e m ovem ent of selected m icrobia l pathogens dispersed in th ree wate r types (rain water, tapw ater, wastewater) w as o bserve d thro u g h t wo san d t yp es co rn m on to th e P erth Coasta l Plai n, using laborato ry sand co lu m ns. It w as fou nd tha t in on e sand type, an increased prese nce o f ca tio ns in the flow solution resulted in faster m ic robial travel. The oche r sand type used in th e experime nts d isplayed an o pposite effe ct w ith an in crease in catio n co n ce ntration slo w ing m ic robial tra vel.

Table 1.. Characteristics of t he m ic robe and a quife r enviro nment t hat affect

microbe t ransport, fa te and mobility. Characteristics of the microbe that affect its transport and fate

Properties of the aquifer that affect microbe mobility

Size Inactivation o r die-off rate Surface e lectrostatic properties Other physiochemica l adso rption characteristics Shape, Cha racter Moisture content Nutrient s upply

Groundwate r flow ve locity Grain size of aquifer/ soil material Type a nd relative amount of pore space Solid organic carbon content Temperature Moisture content Ph Cation exchange capacity Soil wate r flux (saturated vs unsaturated flow}

Introduction Aqu ife r Storage and R ecove ry is em e rging as an im po rtant m eans of wa ter sto rage and re- use. W ith ex p ec te d increases in po pulatio n growth around the Perch M etropo litan region and its subsequ ent increase in w ate r usage, Aq uifer Sto rage and R ecovery m ay pro vide a viable alte rnati ve co surfa ce dams and othe r wate r ho ldin g fa c ilities. O ne of the main concerns w ith th is means of water storage is the po te ntia l fo r co ntamination by m icroorganisms. Should sig n ifi cant quantities of m icrobes travel th roug h the so il to u nde rl ying aq uife rs, th en w ater q ual ity ma y becom e com promised and its app li catio ns after reco very may become li mited . T he study of micro bial m ove m e nt in th e subsu rface has been atte m pted by ma ny researchers w ith studies available o n a m u ltitude o f diffe ring o rganisms. A n um ber o f fa cto rs infl ue nce the pathway and time tha t it wi ll take fo r an o rga nism co travel thro ugh the subsurface. These in clude mi crobial size, so il pro perties, the degree and ability to adsorb to particulate m atter, pH , the presence of sa lts and their concen t ratio ns, te m peratu re and th e charges o n particl es w ith w hich they T his paper is an edited version of the paper which wo 11 the 2000 Weste rn Austra lia n Branc h U ndergrad uat e Water Prize.

42

WATER APRIL 2 001

come in to co n tact (Cra ne and M oore 1984; G an non et al., 1991 ; J anso ns et al 1989; Landry el nl. , 1979; R obe rtso n an d Ed be rg, 1997; Sobsey et nl. , 1980; T oze 1997 ; W o ll um and C assell , 1978 ; Yates and Yates 1988). T able I sum ma,;ses their com m ents. D ue to the many variables that can be invo lve d in m ic rob ial transpo rt through the subsurface, each site m ust be examined for its mi crobial patho ge n transport po ten tial. Until su itable experim e nts have bee n co nducted in the aquifer m ate rial of interest a valid assumpti o n as to ho w m icrobes w ill travel in the subsurfa ce cannot be made. T h is was th e d riving fa cto r be hi nd the studi es carried o u t.

Experimental Methods

w e re u se d fo r t h ese ex p e rim e nts. Polio virus was o btain ed fro m Sm ith Klin e an d Beec ham (Be lgiu m ) as th e Sabine vacc in e st rain , R ocavirus fo r use in co lumn expe rim ents w as extrac ted

Figure 1.. Cryp tosporidium oocysts (3-

Microorganisms

T wo viruses, R.o ca virus and Polio virus, the bacterium E. coli (stra in M 2044) , and the protozoa C ryptosporidi11111 pnrv11111,

4um) s ta ined wit h fluorescently labe lled a ntibodies and viewed unde r 100x m a gnific ation at 540 nm excita tion.

Table 2 . Characteristics of the water types use d in column e xperime nts Wat er Type

Na (mg/ L}

K (mg/ L)

Ca (mg/ L)

Mg (mg/ L)

pH

Ra inwate r Tap wate r Wastewate r

4 .87 42.7

0.54 0 3 .13 22.8

0 .330 14.2 31.5

0.45 0 6 .52 1 1.9

6 .49 7 .1 6 7.59

1 63


WATER

movement of vi ru s. T he results from infe cted faecal sam pl es wo uld suggest t ha t waters ob tain ed from the M icrobio logy containing different cation concenDepartment at Pri ncess Margaret 0 ITllNGE PUMP trations and variati on in pH affect hospital, Perth. Cryprosporidi,1111 the degree with w hic h diffe rent JHIIV/1111 oocysts were also obta ined microorgan isms absorb during the ir from Princess Margaret H ospital, movem ent through the subsu rface. Pe rt h as in fected faeca l sa mples. The adsorption process has also (Figure 1). bee n described as a reversible o ne. Water Samples . Th e three (and this was studi ed in separate water types used included tap flACTION (O ll((IOI W&TU IOUICE l&PS fOI MICIOll&l ll J£CTIOI experiments) . Note that changes in wate r , rai nwater and wastewater. the ion ic e nvironment surrounding Each water type was collected and microbes adsorbed to sand m ay analysed fo r a range of abio ti c Figure 2 . Schematic representation of the col umn, result in the ir remova l and su bsefactors, i. e . ph ysico-c h e m ica l pump and fraction collector. quent transport further through the pa ra m eters (Tabl e 2) . aquifer. Sand. Two sa nd t ypes antibodi es and traditional plate co untin g microorganisms suc h as E. coli Larger (13asse ndea n and S pea rwood sa nd s) m ethods and Cryptospc>ridi11111 showed littl e o r no comm o n to the Perth Coastal Plain wen: retardatio n through the co lum ns. The O ne of the results of t he fra ction o btain ed by hand au ge r from appropriate analysis is shown in Figure 3 in the fo rm most like ly result of their delayed travel sites. Fo r use in col umn and batch studies, of gel e lectropho resis w he re vi rus DNA wou ld be du e to fil tration effects of th e so ils were ste rilised by drying in covered was detected via t he reverse transcriptase sand. T hese resu lts indicate that although stainless steel trays overnight o r fo r a po lymerase chain reacti o n method. fi ltration ma y play a role in rem oval of minimum of 5 ho urs, at I 30°C. then these mic roorga n isms, th e prese nce of sto red in steril e sea led glass j ars at room Results large pore spaces o r fractures in aq uifer temperature. Non-sterile sand was scored Tables 3, 4 show the tin1 es trave lled ma te rial wou ld resu lt in t heir rapid in plastic bu ckets at room temperature fo r for t he differen t pathogens through the transport t hrough the subsurface. The use in fu rth er experime nts. sa nds. It is in te resti ng to note the g reater transport rate of the n1i croo rColutnns. The sand columns used opposite effect that occ urs between the ganism s t hrough the column compared we re approx imate ly 50 cm lon g, 3 .5cm respecti ve sands. Fo r exa mple Pol iovirus to the tracer bromide is du e to chromatodiameter. All columns were used in an trave ls fastest in rainwater when travelling grap hic effects where bromide m oves upwards flow m anner to ensure an even through 13assendean sand but slowest w ith contro ll ed flow rate was maintain ed. through the entire column wh ile th c rainwate r in the Spearwood sand . Figure 2 is a sc he m atic representation of microo rga nisms, being significantly larger, the column set-u p. The water was arc forced to travel through the large pore Discussion pumped thro ugh the column at a constant spaces o n ly. The aim of th is study was to deter111 ine rate of I ml/ min. It has already been concluded by many w hether water quali ty factors such as pH gators that soil type, species of investi Pathogen addition to columns and cation co ncentration aflccted the flow microorganism , infiltratio n rate, presence The columns were o riginall y saturated of microb ial populati ons through sand of org:mic m atter and io nic concentrawith the water type to be used in the types commo n to the Perth Coastal Plain. tions can all affect the adsorpti o n and experim e nts. Th e sa m e wate r was the n Th e expe rime nts were initi ally to be hence movement of microbes through combined with a s111all co ncentration of pe rform ed as a series of ste ril e system s the subsurface Uansons et nl. , 1989; Sobsey bro mid e as a tracer and a slug of the however c irc umsta nces led to th e use o f cf nl., 1980). It is logical to conclude that pathogens injected. Plo tting th e occurboth ste rile and no n-sterile experime n ts a large am o un t of emphasis ca nnot be re nce of bromid e over tim e gave a curve to provide res ults whi c h may all ow placed on ex perim e ntal work ope rating w hic h ind ica ted w hether the colu11111 had analysis of microbi al m ovemen t and very d iffere ntly to a natural system . T he any major packing flaws. Pathogens adso rpti o n . pred ict ion o f mi crob ial movemen t were added to th e co lumns at separate T h e results obta ined from t his experthro ug h the subsurface is a risky process times. Viruses were passed through the im ental work suggested that abi otic co lumn fir st, E. w li seco nd and expe rim ents have no t been co nducted if water qu ality fa ctors do have effects on Cryp to sporid i11111 t hird to usi ng the m ate ri al of interest, minimi se th e block in g of pore th e microorganism of interest spaces within the co lum n and and the wa ter type. Eve n t hus affecting the travel ti111 c. th o ug h laboratory experim ents prov ide va luable inforcan Detection of pathogens mation there is no substitute fo r A numb er of different m easuremen ts in real a nd tec hniqu es were e111ployed to ' natu ral' syste ms. detect the presence o f different

--

species after their m ove m e nt throu gh the sa nd columns as well as in a number of sepa rate adso rpti on studie s. Th ese techniques in cluded R T-PC R and P C R , flu o r esce nt

References Figure 3 . Poliovirus and Rotavirus breakthrough in a Spearwood sand and tap water column. Gel order (left to right): DNA molecular weight marker VI, Poliovirus +, Poliovirus -, Time 0 mins, 32 mins, 60 mins, 90 mins, 120 mins , 150 mins, 180 mins and 206 mins.

Crane SR and Moore JA ( 1984). l3act.:rial polluti on of groundwater: A r.:vicw. JV111a, Air 1111d S,,il Pol/111io11; 22: 67-83. Gannon JT , Manila ! Vl3 and

WATER APRIL 2001

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WATER

Table 3. Time of microbe/bromide appearance (mins) t hrough Spearwood sand columns Water type

Bromide

Poliovirus

Rotavirus

E. coli

Cryptos poridlum

Rainwate r 76 60 56 53 Tap wate r 75 56 60 52 Wastewater 75 52 56 42 46 Increas ing microbi al s ize - - - - - - - - - - - - - - - - - - - - - - - - - -

Table 4 . Time of microbe/bromide appearance (mins) through Bassendean sand columns Bromide

Poliovirus

Rot avirus

E. coli

Cryptosporldlum

Ra inwate r Tap water

76 75

60 64

60 66

52 54

Wastewater

75

64

68

56

55 61 40 = PCR 58

Water t ype

Increasing microbial s ize - - - - - - - - - - - - - - - - - - - - - - - Alexande r M ( 1991) R elationship bet ween

MR..(1989) Movement of viruses after

cell surfa ce properties and transport o f

artificial recharge. Water Research; 23: 293-

bacteria throu gh soil. Applied and E1111iro11111e111al Microbiolo,ey; 57: l 90- 103.

R obertson J 13 and Edberg SC (1997) N atural

Janso ns J, Edmonds LW, Speight B and l3ucens

protection of spring and well drinking

299.

water against surface m icro b ial contaminat ion . Critical R eiliews i11 Microbiolo,ey; 23 : 143- 178. Sobscy M D , D ean C H , Knuckles ME and Wagne r R.A ( 1980) . lmeractions and survival of enteric viruses in soil materials. Applied a11d E1111iro11111wral Microbiology; 40: 92- 101. Tozc S. 1997 Mi crobial Pathogens in wastewat er. Literature review fo r urban water systems. M ulti-divisional research program, CS rn.. O Land and Water Tech n ica l repo rt No I /97, J une, W ollum AG and Cassel DK ( 1978). Transport of microorgan ism s in sand columns. A 11,ericm1 Jcmmal cf Soil Srie11re; 42: 72-76. Yates MV and Yates SR. (1988) M odelling m ic r ob i al fa t e i n th e s u bsurfacl:'. e n vironm ent. C /?. C C l'irical reviews i11 e1111iro11111e111al romml; 1 7: 307-343.

The Authors Julia Rawlinson was an honours stud e nt w it h t he D e pa rtm e nt o f M icro biology at the Uni ve rsity of Western Au stralia. Dr. Simon Toze was her su pervisor and is located at the C S IR.. O in Flo rca t. sim o n. t o ze@ per. clw.csiro.a u

BOOK REVIEW Industrial Water Reuse and Wastewater Minimization (text & C D - R O M) J ames G. Ma1111 & Y .A .Li11 ISBN 0 - 07- 134855-7 McGraw Hill 1999. $247.95 A vailable f rom AWA bookshop, telep hot1e + 61 2 9413 1288 fax + 61 2 9413 1047 email: books hop@ awa. as11 .a11

T hus far, en vironm ental scientists, landscape planners and horticulturalists have tended to m o nopo lise the debate about water reuse and recycling. Their descriptive and wholistic approaches have been excellent and have provided the "w hole o f system " approaches needed to encourage all stakeholders to embrace the concepts o f reuse and recycling. H owever, there is a need to m ove beyond the general co the specific and particular withi n that larger integrated scenario, to identify and refi ne operational and technical issu es - sp ec ifi ca lly th ose o f an engineering nature. This book w ritten by practicing engi neers provides chat systematic and technical input. T he m edium used: process integration viz. water pinch tech nology. Water pinch technology represents an environmen tally signi ficant breakthro ugh in an area of engineering desi gn known as p rocess integration.

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Process integration is a system oriented, thermodynam ically based approa ch that examines an en tire process to develop ways o f integrating materials and energy that minimize both cost and waste productio n. It can either be used for d es ig n in g ne w fa c il iti es o r retrofitting existing ones co create a m ore effi cien t overall system . A common example is the retrofit of heat exchanger networks. In itially, using the basic principles of thermod y n am ics a nd e n e r gy balan ce, en gineers fou nd that th ey could systematically analyse the hea t ÂŁlows across vario us tem peratu re intervals througho ut a manu fac tu ring process and identify a key temperatu re level called the pinch point. Below the pinch po int, external hea ting uti lities are un necessary; above it, external cooling utiliti es are e qu all y u n n ec essa ry. Pro cess design thence fo cuses on max imizing heat transfer between hot and cold screa ms co eliminate th e u nnecessary utilities. Process integratio n technology has advan ced significantly and now includes resources recovery, emissio n control, w ast e re du c t io n and wast ewa te r mi nimiza tion. In its simplest form, water- usin g operations are viewed as

mass transfer processes fro m a contaminant- rich process stream to a water scream. "Contaminants" m ay include suspended solids, chem ical oxygen demand or any other conditions that limit water reuse. As in the heat exchan ge example, wat e r re u se proce ss integrat ion identifies a pinch poi nt called the water pinch point. T his po int is based o n the concentration of a key conta minant rather than a temperature. Streams with contaminant levels above that concentratio n do not require freshwater but can reuse water streams from elsewhere in th e process. U sing this info rmation, system designers and retrofitters can th en m ax imize w ater re use and minimize wastewater generatio n. U ntil no w, this field has lacked a comprehensive text offering a clear explanatio n o f th e process and a complete guide to the application o f water pinch technology to industrial wate r re u se a n d was t ewa t er minirnization. This title fills the gap and there is a CDRO M to assist in application. No t cheap but fo r practicing engineers, ch is is a valuable tool.


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CHEMICAL QUALITY ASSURANCE GIPPSLAND WATER'S JOURNEY P R L Mosse and M Colwell Abstract Ensuring that th e right chemical , of the right quality, is cle liverccl into the right storage vessel, at th e right site, at the right time is a challen ge all Wate r Authoriti es fa ce . Thi s account de tails Gipps lancl W ater's che mi cal quality journey. Th e j o urney c ulminates with the letting of a che mical suppl y contract with de fin ed quality standards for all c hemicals and th e requi rement that each chemica l has a bbo ratory test ce rtifi cate prior to de live ry. Th e associated issues of dclivety procedures arc a lso presented.

Background In 1995 on a routin e vi sit to a Cippsland Wate r fluorid e closin g fac ility, pall e ts full o f polypropylen e bags m ark ed with Asian hie roglyph ics w e re discove red. This " discove1y" alarmed those respo nsible for the treatment of drinking water, as t here was no ade quate indicati o n of the exact contents o f the bag, its level of purity o r indeed whether it w as appro ved for pota ble use. In ea rly 1999 a che mica l o rdere d fo r a partic ular site was de livered into th e wrong rece ivin g vessel, leadin g to the ge ne ratio n o f tox ic gases and th e hm pitalisa tio n of a tanker dri ver. In late 1999 the co rrec t c hemi cal, o f in correct stre ngth was de li vered leading to a disinfc ct;1nt ove rdose. Alth o ugh th ere arc und o ubte dl y m an y simil ar instan ces throu gho ut th e world. o ne whic h was particularl y notewo rthy was an incide nt in till' early I 990's in the UK w he re a tank er lo;1d of alum was deli vered direct to th e retic ulati o n syste m rathe r than into th e desig nated sto rage vessel. These events lnvc progressively influ e nced the design of Gippsland W ater's total c hemic al suppl y system. Broadl y th e o bjec tive is to m anage all issues associate d w ith the storage, use and handling o f water tre:1tment chemicals that have the po tential to adverse ly impac t upo n the health and we llb e in g o f sta ff, co ntrac to rs a nd customers. Th e spec ific c hall enge that Gippsland Wate r faces is to e nsure that th e right c he mi ca l, of th e ri g ht quality, gets delivered imo the rig ht storage vessel, at th e ri g ht site , at th e ri ght time.

Figure 1. Unidentified chemical recently discovered at a GW WTP

The Journey In the absence of any Australian g ui delines o r testing procedures, Gippsland Wate r has, since 1996, bee n developing a syste m to ensure best practi ce che111i ca l suppl y and use. Gippsland W ater has tak e n a 111ultifa ce ted approach driven by interna l occupatio nal health and safety co ncerns, and the need to dc111o nstrate due diligence with regard to th e pote ntial health e ffects o n customers. The fi rst stage in th e j o urney wa~ to clearl y ide ntify and bbe l chemi ca l storage vessels, fillin g points and de li ve ry pipe work at all G ippsland W ate r sites. Prior to this, many sites had multiple un b bell cd ex te rnal ca mloc k fittin gs lined up next to o ne an othe r, with th e storage vessels hidden inside the bui lding. l3unding was o fte n e ith e r no n-e xi ste nt or inadequate. Improved bunding and appro priate tank venting has no w been installed. Pri o r to Aug ust 2000, Gippsland W ate r did no t have a contract for th e supply o f treatment c hemica ls. Altho ug h m ost o f the chemicals were suppli ed by o ne company, there w ere instan ces of staff orderi ng che mi cals fro m whichever suppli er could provide th e most co mpe ti tive price, o r from a prefe rred loca l supplier. This prac tice provided no accountability for the quality of chemi cals supplied , and records relating to th e supply, delivery and use o f parti c ular batc hes o f c hemi ca ls were in comple te o r non -e xiste nt. While researching alternati ves to address these shortcomin gs, Gippsland W ater became aware of th e National Sanitation

Foundatio n (NS F) . NSF Inte rnatio nal is an independe nt, no n- profit o rga nisa ti o n , based in the United States of Ame ri ca , w ith programs coveri ng public healt h safety and e nvironme ntal quality. NSF Inte rnationa l is also recog nised by th e W o rld H ealt h O rganisa tio n (WHO) as a world leade r in t he area of d rinking wa ter safety and sanitati o n. NS F Standard 60, w hich applies to the che m icals that G ippsland Wa te r uses, was develo ped in the Un ited Sta tes by NSF International, regulatory agencies, industty, water supply compa n ies, con sultants and end use rs, to esta blish minim u m requ irem e nts fo r the quality of products added to drinkin g w ate r durin g th e t reatme nt process. G ippsland Wate r m ad e a stra tegi c dec isio n to p rogressively ado p t N SF Standard 60 accredi tation o f treatme nt c hem ica ls, and approached o ur largest supplier, loca l company Aluminates P/ L, to attain this accreditatio n. In itia lly th ere was so m e reluctance to m ee t thi s req u est, as Gippsland W ater was the o nly W ater Auth o rity in Au stralia makin g suc h dem ands. H owever, Aluminates P/ L soon o bliged and becam e t he fi rst chem ica l suppli er in Australia to achieve NSF certifi cation o f their M o rwell site for t he ma nu fac ture of seve ral la rge vo lume water treatm e nt che mi cals. The next step in vo lved th e preparatio n of deta iled qu ality specificatio ns fo r each treatme nt che mi cal used by G ippsland W ater. The majo rity of this work has bee n completed, and incorp o rated into the rece ntl y let C hemi ca l Supply C ontract. Pre parati on of th e spec ifica ti o ns was difficult. Since no Australian guidelines were ava ila ble to assist in th e preparation o f t he specifica tions, overseas experience was draw n upo n. In addition to gu idance fro m NSF, C ippsland Wa te r utilised th e W ate r C hemica ls Codex 1 and th e Ame rican W ater W o rks Associa tio n Standards2 and adapted them to suit local applica tio ns. Part of the specification required the supplier to provide a certi fie d analysis o f th e produc t, and/ or an affidavit sta ti ng that the product compl ied with all requirem ents (particularly che mi cal qu ality) o f th e specification . Gippsland W ater was not prepared to accept t he de li vered produ ct fo r use unless acco mpa nied by this documenta tion. WATER APRIL 2001

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Tenders fo r the su pply and deli ve1y o f all treatment chemicals (w ith the exceptio n o f gaseous chl orine and liquid oxygen), which included the spec ificatio ns, w e re ad vertised in late 1999. Almost thirty co m p a ni es ap p lie d fo r th e t e nd e r doc um e nts, bu t on ly two tenders w ere eventually submitted. D uring the tendering process, G ippsla nd Water rece ived hostile inqui ries about the req ui re me nt for NS F certifi cation fro m se ve ral com panies w ho fa iled to submi t tenders. Fe w co m pa nies w e re prepared to ve nture down the track to achieve NSF certifi cati o n to comply w ith the requirem ents o f o ur specificatio ns. In fa ct, apart from the successful re nderer's bid , Gippsland W ater w as ex tre mely disappointed by the lac k of com m itm e nt of chemical supply co m pa ni es co provide adequate guarantees that th eir product m et the req uire m ents of o ur specifi cati o n . It must be noted that the m aximum contaminant levels (based o n the W ater C hemicals Codex) m entio ned in the specifi cations w ere no t onerous. Th e contract fo r th e suppl y and delivery of treatm ent c he micals was let in Aug ust 2000 fo r an initial pe ri od o f two years. The successfu l tenderer, Alumi nates P / L, felt this pe ri od w as insufficient to j ustify t he necessary e xpend iture to m eet the new requ irem ents o f the con tract. A case was pu t to t he G ippsland Water .13 oard for a lon ger pe riod and th e contract period w as extended to th ree years w ith th e o pti on o f two furthe r years. As a resu lt of the additio na l costs inc urred by the suppli er to comp ly w ith th e qua li ty requ ire m e nts o f the c he mical su ppl y co n t ract, G ipp sla n d Wate r 's chemical costs have risen by approx im ately 12%, based o n the u nit pri ce of ea ch c he mica l. Si nce th e co m m en cen1e nc of th e co ntract a n umb er of admin istrative and delivery procedures have been established and progressively im ple m e nte d. • Alum inates P / L appo inted a full tim e Safety and Quality Assurance o ffi cer as part o f a program to provide improved service delivery to the ir custom e rs. • A d ri ver ind uction syste m has been established fo r each Gi ppsla nd W ater site. Each dri ver is inducted o nco each site and appropriate reco rds kept. T hese includ e an individual driver record , w hich can be inspected by G ippsla nd W ater operatio nal and m anagement staff at any tim e, and a central database reflecti ng the c urrent site status of all dri vers. T he G ippsland W ater staff m ember respo nsible for the site perfo rms the site indu ctio ns. • Th e requirem ent fo r a ba tch analysis ce rtifica te to be o bta in ed prior to an y deli very has necessitan:d th e establishm ent

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of q uarantin e tanks at the Alu minates site. Quarantining of batches at the facto1y, and NAT A accredited testing according to the requirem ents o f the c he mica l spec ifications, has now com m e nced. C he m ica ls w ill no lo nger leave the Alu minatcs site un til the testing is comp lete and anal ytical reports received, show ing compliance w ith th e c he mi cal q uali ty specifi catio n . • Formal checklists have been established to co ver the dispatch and delive1y process. A gross visual check is carri ed out o n th e product before it leaves the Alum inatcs site and an operato r no t directl y involved w ith t he batc hing process checks tha t th e batchi ng has been unde rtak en in accordance w ith w o rk instructi o ns. At the G ippsland W ater site, the order is veri fie d and both t he Alum inates dri ver and t he Gippsland Water o perator ensure that the rig h t che m ical is de live red to th e righ t sto rage vessel under sa fe o perating condit io ns. T h e c he cklists arc fill e d o u t acco rd in gly. • I 11 the past, delivery o f chemi cals cou ld occur w itho ut the presence of a G ippsb nd Water operator. C hemi ca ls can now o nl y be delivered w he n an o perato r is present. The d river and th e ope rator j oi ntly co m plete Part I of the de live ry checklist prior to the transfer of goods, and co111 ple tc the seco nd part o f t he checklist pri o r to the truck leaving the site and after the tran sfer is co 111plctc. • Prod uct spec ifi c delivery hoses and fa cto ry storage vesse ls have been established at the Alumi natcs site. To fu rther li mi t p oss ible c ross co nta m i n at io n A lu 111inates ha ve im p le m e nted w ashing p roced ures for delive ry vessels and hoses. • Previously, de livery hoses we re allowed to dra in to th e grou nd o r in som e cases to a confi ned area after com ple tio n o f the delivery. T o prevent this adverse and un sightly impact o n th e e nviro nm ent , an air purge system has been im plem ented to all o w an y produc t left in the hoses to be blow n bac k to th e ta n ke r. T he hoses are th en capped prio r to leaving th e site. • In the past t he re w as 11 0 acco un tabi lity fo r incorrect batch ing of che m icals o r incorrec t de live ries. Alu m inates have now im ple m ented a stafl:.training program that incorpo rates disciplinary and dism issal pro ced ures . The fi nal step in the journey is th e co mpletio n and re fi ne m e nt o f docum e ntatio n, inclu ding d igital p ho tog raphs and detail ed maps o f G ippsland WHe r sites , with the locatio ns o f fi ll poin ts , scorage vessels and safety e qui pme nt clearly ide ntifi ed. All th is in fo rm atio n is be ing located in an Em ergency box situated at the e ntry gates to th e sites. T he in fo r111ation is also bein g distribu ted to th e

che m ical supply compan y, to assist w ith tan ker d river inductions o nto Gippsland Wate r sites. An addi ti onal bene fit of th is docum entati o n has been a streamlinin g of the de li very process, as drive rs are no longe r getting lost or driving past inconspicu o us dri veways leading to dosing sites in re mote areas. The im ple m e ntat ion o f the c he m ica l supply "package" has re qu ired a chan ge o f c ulture fo r bo th Gippsland Wate r o pe rators and Alu mi nates sta ff Ed ucation and training sessio ns o n risk m anagem ent and H AC C P have bee n co ndu cted for both groups. In gene ra l, the prog ram has progressed w e ll to date. A partic u larl y diffi cult o bstacle to overco m e has been the ide ntifi cati o n o f a suitable laboratory to carry out the n ecessary testin g in the requ ired timeframc. D e la ys in receiving resul ts fro m laborato ries have led to delays in releasing product fo r use. There are also o ccasio nal lapses in adh erence to o rdering and de li very proced ures. W ith co ntinu ed reinforcem e nt and imm ed iate fo ll o w up w it h in divid uals, the aim is co achi eve I 00% compl iance wi th t he req u irem e n ts of the pa ckage.

Conclusions Over a period o f fiv e yea rs, G ippsla nd W ater has progressively m oved to establish a system to ensure th e re liabl e delivery o f quality trea tm ent chemicals to its treatm ent sites. T his lu s involve d mo di fi cation to de live ry po in ts, t he establish m ent o f de ta iled c h e mi c al sp ec ifi ca ti o ns an d recen tl y th e letting o f a full QA spec ifie d chem ical co mract. Since th e letting of th is co ntra ct, Gippsland W ater has w o rked w it h the successful c h em ic al supp ly company to deve lop dispatc h and de livc1y proce d ures, w hi c h aim to lim it hum an error, o r to ide ntify it before it has adverse co nsequ ences. T he e xtra req u irem e nts have increased t he co st of c he m ical suppl y to Gippsland Wate r, ho weve r G ippsland W ater secs t hi s increase as a necessary co nseq uen ce o f a p rogram designed to ensu re t he on go in g health o f its em ployees, co ntrac tors and customers.

References I . Water C hem icals Codex, National Academy Press, Wa, hingro n D. C. 1982 2 . Am er ica n W a te r W o rk s Assoc iati o n , American Nat ional Standard.

The Authors Dr Peter Mos s e ( m osse p @ g ipp swa t c r .c om .a u ) is t h e Wat e r T reatm e n t M a n age r an d Michelle Colwell (co lwe ll m@gippswate r.co m .au) is a Water T reatme n t T echn o logist at G ippsb nd Water, PO Bo x 348, Traralgon , Victoria 3844 . Pho ne 5 177 -l-600.

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Water Journal April 2001  

Water Journal April 2001