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Volume 29 No 6 September 2002 Journal of the Austra lian Water Association

Editorial Board F R B ish o p , Chairma n B N Anderson, R Considine, W J D u lfer, G Finke, G Finlayson, G A H older, B Labza, M Muntisov, P Nadebau111 . J D Pa rker, J Riss111an, F Roddick, G Ryan, S Gray

CONTENTS

', 11/nrcr is a refereed journal. This symbol indicates that a paper has been refereed.

Submissions Instructions for authors can be found at the back of this journal. Sub111ission s accepted at:

OPINION 2

,.,v,v,v. a,va. asn .au/ publications/

Managing Editor

Introducing the Global Water Partnership to Australia; Aquaphemera; Barriers Versus Tests; Infrastructure: Where To From Here?; Tragic Decline of Groundwater Resources Worldwide, Lance Enclersbee; What's Wrong with Sewage?; Pratt's Pipe Dream

Pet er S tirling

ASSOCIATION ACTIVITIES

News and Supervising Editor

10

B r ian M cR ae AW A Technical Director Tel : (02) 9413 1288 Fax : (02) 9413 1047 Email: bmcrae@awa .asn.au

Technical Editor E A (Bob ) Swinto n 4 Pleasam View Cres, Wheelers Hill Vic 3 I 50 Tel/Fax (03) 9560 4752 Entail: bswimon@bigpond.nct.au

PROFESSIONAL DEVELOPMENT 14

PO Box 84, Hampton, Vic 3188 Level I, 99 Bay Street, Brighton , Vic 3 I86 T el (03) 9530 8900 Fax (03) 9530 891 I E111ail: hallmark@halledit.com.au

Details of courses, classes and other upcoming water events

NEWS BYTES 15

Featuring selected highlights from the AWA email News

CROSSCURRENT 19

Water Production Hallmark E ditions

Including AIWA and WEF Reports

We All Use Water; The 2001 WA Undergraduate Water Prizes; Security and Water Systems; Sydney Water Priority Sewerage System

CONFERENCE REPORTS 24

Water and Public Health in Regional and Rural Australia; Microorganisms in Activated Sludge and Biofilm Processes

Graphic design: Mitzi Mann

FROM THE JOURNAL COMMITTEE

Water Advertising

27

Natio n al Sales M a n ager: B rian R a ult Tel (03) 9530 8900 Fax (03) 9530 891 1 Mobile 04 1I 354 050 E111ail: brault@hallcdit.com.au

Water (ISSN 0310 - 0367) is published eight times a year in th e months of February, March, M ay, June, August, September, Novc111ber and December.

Australian Water Association PO Box 388, Artannon, NSW 1570 T el +61 2 94 13 1288 Fax: (02) 941 3 1047 Email: info@awa.asn.au VI ABN 78 096 035 773 ,W,

A, A

Federal President

Chris Davis

CRC FOR COASTAL ZONE, ESTUARY AND WATERWAY MANAGEMENT 28

OVERVIEW: Their research impinges on effluent discharges

30 THE ADAPTIVE MANAGEMENT FRAMEWORK FOR COASTAL ENVIRONMENTS A'learn-as-you-go' system. P Lawrence, J Benne tt 37

LONG TERM MONITORING OF ESTUARINE WATER QUALITY: BRISBANE RIVER TURBIDITY How tidal range affects river quality. T Howes, C Lcmckcrt and A Moss

40

WET WEATHER SEWAGE OVERFLOW ABATEMENT PROJECT: LOTA CREEK PILOT STUDY On-line monitoring of storm discharges. P Po lla rel

WATER

Barry Nor111a n

Executive Director

Water: Our Plans for 2003

AUSTRALIAN

47

WATER

ASSOCIATION

Australian Water Association (AW A) assume~ no responsibility for opinions or statements of facts expressed by contributors or advertisers. Editorials do not necessarily rcprcsellt official AW A policy. Advertisements are included as an information service to readers and arc reviewed

before publication co ensure relevance to the water environment and o bjectives of AWA. All material in Wnrer is copyright and should not be reproduced w ho lly or in part without the written perm ission of the Managing E ditor.

•, GROUNDWATER: CAN WE AVOID THE MISTAKES OF THE PAST? America has polluted some very valuable resources. T C Harmon

ENVIRONMENT 53

, ENDOCRINE DISRUPTION: AN AUSTRALIAN PERSPECTIVE Areview of both overseas and local concerns. G-G Ying, R S I<ookana

58

·, ENVIRONMENTAL FLOWS· AN ECOLOGICAL PERSPECTIVE Strategies for effective river restoration, G Qu inn and M Thoms

WASTEWATER

Wnrer is sent to all AW A members eight times a

·, THE BIOWIN MODEL: RECALIBRATION FOR N·REMOVAL: PART 1 Using the old default parameters results in inadequate design.

year. It is also available via subscription.

D W de Haas a nd M C Wentzel

Subscriptions

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

62

OUR COVER: Hill Inlet, vV/1its1111day Isla11ds, Q11eensla11d. A recent National Lan d and vVater R esources A11dit report assessed A ustralia's 979 est11aries . ltfo11nd 50% are i11 11ear-pristi11e co11ditio11, 22% are in largely 11111110d!fied condition, 19% are in 111od!fied condition, a11d 9% are in exte11si11ely 111odif,ed condition. Photo b)' courtesy of C R C f or Coastal Z one, Estuary and Waterway Management. WATER SEPTEMBER 2002

1


FROM

THE

PRESIDENT

INTRODUCING THE GLOBAL WATER PARTNERSHIP TO AUSTRALIA After a little over a year of dialogue, we have moved towards introducing the Global Water Partnership (GWP) in Australia. I am very pleased to see this unfold, because the GWP, like AW A, is ded i cate d to sus t ainable water management. Its international, governan ce-focused approach is a good complement to AWA's Australian base and our strongly technical membership. For readers unfamiliar with the GWP, a short introduction follows. The impetus to set up GWP in 1996 came from a global concern over th e need to implement the goals expressed at the 1992 Rio Summit. GWP has a small secretariat in Sweden, servicing a global network of regions, countries and local areas working for sustainable, integrated water resources management. GWP's activities include: • Encouraging the development of active partnerships in regions and countri es, raising political will; • Informing the public abo ut integrated water resource management (IWRM) ; • Providing strategic assistance to active partners in the context of IWRM; • Supporting the exchange of knowledge about good practices in IWRM; • Promoting dialogue on key IRWM issues; and • D eveloping concepts and ideas for putting IWRM into effect. Australia is no laggard when it comes to IWRM, so we have a lot to offer the rest of the world. Despite our leading position, we still have major chalJenges to face; so interacting w ith ochers, through GWP, will help us move forward. A Toolbox on the GWP website (www.gwpforum.org/) provides information on enabling environme n ts, in s titut ional arrangements and management instruments. The site also has case studi es and lessons learned, including several from Australia. GWP will be leading a section of the 3rd World Water Forum in Japan next March, looking at governance. GWP grou ps have produced valuable discussion papers on water policy in their regions and GWP mainta ins a productive dialogue with aid agencies to optimise their projects in developing countri es . GWP is based on the principle of inclusivity, a mu lti-disciplinary and multi2

WATER SEPTEMBER 2002

Barry Norman

sector make-up, as well as a healthy gender balance. Any organisation is free to join GWP itself, the only requirement being to subscribe to the principles it espouses. In moving to establish the GWP Country Partnership in Australia, AW A supports all those principles and is inviting government agencies, the private sector, NGOs and other associations to take part. Environment Australia has generously agreed to provide funds to help get the GWP started in Australia. At th e time of writing, we plan to convene the first open meeting of GWP participants during the Riversymposium in Brisbane. Other meetings will be held to enable organisations to attend with minimal travel, and feed back will be collected from everyone attending. I hope a steering committee of representatives from interested organisations will be created to take chis idea forward. AW A bas offered a to act as the pro tern secretariat for GWP Australia, but the long-term arrangements m use emerge from the participants. With the diversity of water organisations in Australia, at both the governn1ent and not-for-profit levels, the GWP offers a good, neutral base for discussions and actions to achieve sustainable water management for Australia. It also offers an effective channel for communication with oth er GWP nodes, in our neighbouring regions and worldwide. Barry Norman

Aquaphemera The good news about the Snowy River is being rep licated aro und Australia. In the ACT , ActewAGL is required to release environmental flows as part of its license to take water fo r domestic an d commercial supply. Annual releases are based on the 80th percentile flows. An additional fis hspawning flow, fixed at the 50th percentile during the spring months, is a further requirement for 2 out 5 years. During drought, these releases can be reduced at the discretion o f the regulatory agency. ActewAGL, the ACT EPA, ECOWISE Environmental, and the CRC for Freshwater Ecology, are together undertaking cooperative research to understand the impacts of the flow releases e.g on two endangered fis h species that take refuge in the Cotter River: Macquarie Perch that migrate up to 20 kilometres overnight and have a preference for running water, and the Two- Spined Blackfish that have a home range of no more that 150 metres and pre fer quie scent co n ditions. However, the environm.ental flow release project is only two years into a five year evaluation phase. There is a very long way co go before we have even a reasonable understanding of the benefits of this pioneering project. The direct impost of the 30 Gl/a environmental flow release can be readily inferred. Ac current consumption rates, thi s will bring fo rward a requirement for a new dam by some 20 years. Less clear, however, are the ecological benefi ts or the way the community values them. Before we commit further scarce community resources to this very worthwhile cause, we must develop an environmental balance sheet to enable informed decisions co be made about futu re flow releases. Ross Knee

Fish ladder at Vanities Crossing on Cotter River


FROM

THE

JOURNAL

COMMITTEE

WATER: OUR PLANS FOR 2003 Submissions The Committee invites submission of material for publication in the following categories • Technical papers, which will be peer reviewed. (3000 - 4000 words) • Articles on recen t major projects: manageme nt , e ngin eer in g (design , constru ction, implementation) . e nvi ronm en tal (1000 - 4000 words ) • Reviews of "State of the Art" tec hnology and pra ctices. (1500 - 3000 words) • Water reso urce and environmenta l protection poli cies • Conference reports. • Tech ni cal notes on new equipm ent, p rocess design , analytical m eth ods, economic evaluation and training. (1000 - 1500 words) T he submissions accepted should fall into one of th e fo llowing segments Water: Wastewater: Environment: Business. Submissions will be tabled at the monthly Journal Committee meetings and assessed for suitabili ty . Guidelines for Authors are published in eac h issue, but to sum marise, a page of th e Journal contains about 1000 words, less allowance for graphics. Papers of three to four pages are the optimum. Longer papers are only justified if th ey contai n large amounts of useful data. Deadlines Articles a11d reports: Usually six weeks is

particular issue should be submitted, even in draft form, about three to four months before the publication date. When published, the final paper wi ll be annotated as a referee d pape r. H owever, there can be no guarantee that a paper or article can be fitt ed into the page allowance for each particular issue, but if not it wiLI take its place at the head of the queue for the next issue.

Major Themes Th e Journal Co mmittee has planned a series of features for 2003 . It is hoped that about half of eac h issue, ie fo ur or fi ve papers, wiLI comprise papers relevant to the particular theme. T he remainder of each issue will be availab le for oth er technical pap ers, repo rts, co n fe re nce reports and review articles on the other 'water' subjects encompassed by the generic headings. Note that the Journal occasionally selects papers w hich have been presented at AW A Conventions and Branch Sern.inars, which may be published afte r updating and editing. The Major Themes we h ave nominated for the 2003 issues are as follows, with just a few suggestions of topics wh ic h cou ld be addressed. Th is list will be continu all y updated. February 2003: Water Treatment Deadli nes: Papers October 7th. Articles November 29th eg. CR.C WQT, new treatment plants, disinfection, chemical feed ing systems, reticulation problems, e tc.

needed for assessment by the monthly J ournal Committee and for the Editor to conduct the to-and-fro pro cess of editing and checking of the graphics before filing with the publishers. Tec/111ical papers: These wi ll be peerreviewed, and the referees' co mm e nts addressed by the author(s) . This process takes time, and a refereed paper for a

March 2003: Pumping, pipelines, instrumentation Deadlines: Papers November 29th. Articles January 3rd. eg. D esign and construction of water and sewage pumpi ng stati ons, pipelines, maintenance, corrosion, con trol syste ms, surge suppression, etc.

water

May 2003 Environmental Planning and Wastewater Treatment Deadlines: Papers January 3rd. Articles February 28th eg. River basins in Australia o r overseas, environmental impact studies, biological indicators. Wastewater treatm ent: nutrient removal, odou rs etc.

FUTURE MAJOR FEATURES October

Odour, copper corrosion

December

CRC Freshwater Ecology

Submissions for the October features will be very welcome

June 2003: Biosolids Deadlines: Papers February 28th. Articles April 4th eg. Sludge management for smaLI and large plants, safety and economics of disposal or use, safety, water treatment sludges, desludging lakes and lagoons, ere.

August issue: Sustainability and re-use Deadlines: Papers April 4th. Articles May 30th. eg. Natural resources, policy on re-use of water, quality fo r beneficial use, overseas practice etc. September 2003: Industrial Waste Treatment Deadlines Papers May 30th Articles July 11th. eg. Case studies, trade waste acceptance standards, cleaner production, economics, etc. November 2003: Irrigation, Cost of Water, Asset Management Deadlines: Papers July 11th Articles August 29th . eg. Past and c urrent practi ces, e nvironmental impacts, eco nomi c benefits, infrastructure . Asset management issu es, water and sewerage, etc. December 2003: Catchment Management and Hydrology Deadlin es : Papers August 22nd Articles October 10th. eg. Minimising con tamination, pathogen identification, biological indicators, raintalJ and runoff models, regulation, stormwater managem ent etc.

water

Contributions Wanted The vVat er journal welco mes the submissio n of papers equivalent to 3,000-4,000 word~ (allowing for graphics) relating to all areas of the water cycle and water b usiness to be published in the journal. Topical stories of up to 2,000 words may also be accepted. All submissions of papers intended for the m ain body of the journal should be made thro u g h the AWA we b site at : www.awa.asn.au/ publications/. Shorter news items may also be submitted there or may be em ailed to: news@awa .asn.au . Submitted papers will be tabled at a monthly J ournal Committee meeting where, if appropriate. it w ill be assigned to referees. Their comments w ill be passed back to the principal aurhoc If accepted and afLer any cooun<!nts have been dealt with, the final paper can be emailed with the text in MS Word but with high resolution graphics (300 dpi tiff, jpg or eps files - Z ip disks or CD-R.OMs can be accepted) in separate files or hard copy photos and graphics suitable for scanning by the publisher can be mailed to 4 Pleasant View Cres, Wheelers H ill, Vic 3150.

WATER SEPTEMB ER 2002

27


COASTAL CRC

Overview

such as a recent estuary audit in volving • James C ook University an assessment on the condi tion of more T he C ooperati ve R esearch Centre fo r • CS IRO than 900 estu aries arou nd Australia in Coas tal Zone, Estu ary and W aterway • Queensland Department of Primary conjunctio n with the Natio nal Land and Managem ent (Coastal C R C) provides Indu stries Water R esources Audit. T he participating decisio n- making too ls and kno wledge • Queensland E nvironmental Protection organisatio ns are : necessa ry for th e effec ti ve manage men t Age ncy and ecosys tem hea lth of Au stralia's • Geosciences Australia • Queensland Departm en t o f N atural coastal zone. The seven- year $63 million • Brisbane C ity C ouncil R esources and Mines resea rch and development program is a • Central Queensland Un iversity As well , th ere are a n um ber of other j o in t ve ntu re be tw ee n th e fe d eral • Griffi th U niversity o rganisations, government agencies, local governmen t and several public sector and autho riti es and NG O s that are associated • The Uni versity o f Quee nsland private organisations. lt is m anaged by a Go vernin g Bo ard and in volves with the Coastal C RC. They coa stal re sear ch e rs, pla nner s, include the Quee nsland Industry edu cators and managers. An outl ine Seafood Association, Queensland of all research projec ts is listed at: Ports C o rporation, Great Barrier CRC for Coastal Zone www. co as ta l.crc.org.au R ee f Ma rine P ark Auth o r ity, Estuary & Waterway Management Th e goal o f the Coastal C R C is Sunfish, Fitzroy Basin Association, to bridge the gaps betwee n science, E nvironment Australia, N ew South Contacts the com munity and policy, planning W ales Coastal Co uncil, an d many CEO D r R oger Shaw - pho ne 61 7 3362 9399 an d decisi o n-makin g organisa tions . others . Email: roger. shaw@nrm.qld.gov.au T he Ce ntre carri es o ut q uality Functions with local stakeholders W ebsite: www.coastal. crc.org.au sc ience wit hin five interlinked are often organised during Board them es in m anagement study areas Management Study Areas meetings, proj ect tea m m eetings, usin g pa rticipatory approach es with program workshops and research Port Curtis region stakeholders. T he science is applied M eetings wi th se ni o r reviews. Alistair M elzer - phone 61 7 4970 7285 in management study areas, initially: rep resen tatives o f govern m en t, E mail: a. melzer@cqu .edu .au • a maj or agricultural catchment at indu stry and community organisathe Fi tzroy River Fitzroy region ti ons are held fr equ ently w it h • a maj or industri al catchment at Bo b Noble - ph one 61 7 4938 40 17 Bo ard members. Port C urtis Email: bob.noble@nrm.qld .gov.au C R C C hairman, Th e H on. Dr • a m aj or urba n ca tc hm en t at Barry Jones A O, C R C Board Brisbane River and Morton Bay region Brisba ne R ive r and M oreto n Bay members and executive staff also R ob Fearo n - pho ne 61 7 3362 9399 Th e Coastal CRC also coordi liaise with a N ational Stakeholder E m ail: robert.fearo n@ nrm.qld .gov .au nates nationa l research activities, Ad visory Com mi ttee .

28

WATER SEPTEMBER 2002


COASTAL

CRC

Regional stakeholder advisory groups

Coastal C R C researchers and Fitzroy region stakeholders work together with the Fitzroy Basin Association (FBA) to ou tline progress of several CRC-Fitzroy Ri ver Basin projects and in vestiga te ways to integrate research resul ts with the Central Quee nsland Strategy for Sustainability . R epresentatives from various commercial fishing, farming, local council, state government agency and Indigenous community organ isations participa te in workshops to ou tline knowledge needs and discuss lo ng term planning strategies for the region. Stakeholder groups work closely with sciencists undertaking water quality, monitoring, fisheries and remote sensing field work. R egular meetings of the Port C urtis Stakeholder Advisory Committee are also held on progress with researc h tasks, edu cation and communication initiatives including the Port C urtis Integrated Monfroring Strategy. A committee was established to manage the strategy. It comprises representatives from Gladstone industty and the Environmental Protection Agency, Central Q ueensland University and the Coastal CRC. Th e Coastal C R C co llaborates with the Moreton Bay Waterways and Catc hmen ts Partnership to provide data and reports from several projects including resul ts of the Brisban e R iver tu rbid ity, Bremer R iver ecological processes and modelling, and environ mental planning projects. R esearchers presen t results to the Scientific Expert Panel, other staff and commu nity groups. Coastal research themes

T here are five research them es: Decision Frameworks

Aims to develop frameworks to facilitate coastal zo ne d ecision making through the integration of ecological, social, economic, cultu ral and legal considerations. The fram eworks allow decisio n makers to integrate knowledge with differe n t stakeho lders and objectives. Citizen Science and Education

Aims to increase community participation in coastal research, planning and decisio n making, an d to facilitate training for stakeho lder gro ups. The them e also provides postgradu ate scholarships and suppo rt for studen ts. Planning and Restoration

Aims to develop plannin g an d restoration options and strategies to improve government environmental plann ing regulations, and enhance ecosystem health for includin g river tu rbidity, open coastlin es, eilluent managem ent and wetlands. Ecosystem Processes

Aims to understand and predict coastal ecosystem behaviour, particularly responses to h uman activity, to support planning and ma nagement decisions. T he theme develops predictive m odels that simulate managem ent opti ons for the coastal zone. Assessment and Monitoring

Aims to develop health indicators and remote sensing tools that accura tely assess and m on itor ecosystem health of the coastal zone. T he theme, w hich included an audit on the condition of Australian 970 estuaries, evaluates the effectiveness of m anagem ent and protection m easures, and provides a longterm framework for local, state and nati onal planning.


COASTAL

CRC

THE ADAPTIVE MANAGEMENT FRAMEWORK FOR COASTAL ENVIRONMENTS P Lawrence, J Bennett Summary T his paper describ es a framework for decision making and m anagem ent in an uncertain environment. The framework is designed to overcome many barriers that have plagued traditional efforts to reach long term collaboration and consensus by taking up the concept of "learning by doing". T he framework, known as the Adaptive M anageme nt Framework, provides a structu red and grounded basis for moving fo rward. R ealistic partnerships for learning by stakeholders are supported. Introduction Most plann in g a nd m an agement decisions are surrounded by uncertai nty. The difficulties of dealing with uncertainty and complexity arises for a number of reasons, including the time constraints to undertake detailed investigations, or that existing data and information are disconn ected in time, space and fu nction , o r perhaps the knowledge required to fully understand the plann ing issue cannot be assembled from the pieces of disjointed in formation . This n otion of disconnectedn ess between sources of inform ation is expressed very well by Marshall (1995, p .147): " If y ou don 't sy nt hes ise knowledge, scien tific journals become spare-parts catalogues fo r mach ines that are n ever built. Unti l isolated and separated pieces of information are assimilated by the human mind, we w ill continue to rattle around aimlessly". The concept of adaptive management is born in the domain of in creasing our understanding _of systems as a whole through active participation and learning, evolving experimentation, reviewing and responding. The focus is on action and learning, not in preparing to learn (Lee 1999). Adaptive management is seen as the preferred choice of changed management and poli cy development when the risk of trial-and-error methods is too high and decisions canno t be postponed w hile further data are collected given the long timeframes for ecosystem responses. In addi tion, the adaptive m anagement approach assumes that systems are resilient and flexible. Notwithstan d ing these

30

WATER SEPTEMBER 2002

Members of the Coastal CRC's Decision Frameworks research team include (from left) Roger Shaw, CEO (standing), Don Kerr (standing), Paul Lawrence, John Bennett, Regina Counihan, Jessica Wallwork (standing) and Donna Barry.

benefits, adaptive man agem ent is time consuming as causal responses are revealed and understood (Walters and H olling 1990), costly in time and resources and most li kely in volve some elem ents of conflict between participants. Adaptive management can be defined as "a systematic process for continually improving management policies and practices by learning from the outcomes of operational programs". It in volves synthesising existing knowledge, explo1ing alternative actio ns by making predictions about fu ture trends and outco mes, then agreeing on and implementing the preferred strategy. Further actions and obj ectives are then based on improved understanding and outcomes of monitoring and review. The adaptive management process assists decision makers to make informed choices on management actions particularly where integrated knowledge is required, there is scientific uncertainty or where scientific expe rim e nts are very costly,

impractical or results are inconclusive and where non-scientific information needs to be incorporated. Under the National Action Plan for Salini ty and Water Quality (NAPSWQ), Australia has co mm enced a program of unprecedented develop m ent and implementation of integrated natural resource planning at a catchment scale . One of the prima1y challenges in the NAPSWQ is to develop appropriate plans that achieve sustained use of resources through an agreed partnership of indust1y, community and government sectors. H owever, as this program begins its implementation, there are no established guidelines o f the structures and processes for achieving these desirable outcomes. Indeed, there is a real risk that achi eveme nt s under the NAPSWQ will be sub-optimal unless there is a transformation from tokenistic participation to one of p artnerships with capacity for learning and ongoing refining of agreed catchment plans that address env ironm en ta l, socia l, cu ltura l and economic facto rs.


COASTAL

Why a framework? A frame work simply shows how the components of integrated catch m ent management and the associated cools fi t together. Th e key advan tages of the cyclical adaptive management framework are the processes co proceed , evaluate and respond when there are considerable gaps in knowledge and uncertainty, by specify ing actions, monitori ng and adjustm ent of vi sions, targe ts a nd asso c iate d ma n agement p rac tices. The proc ess explicitly i ncorp orates a wide range of stakeholder involveme nt an d negotiation, an ecosystem level u nderstanding and the monitoring of the impacts of c hanges in m anagement p ractices. There are a number of criticisms of the adaptive management processes. These range from a lack of flexibility by instit u tions and an imbala n ce b e tw ee n assessment and management to little or no resilie nce in the components of th e ecosyste m (Gunderson, 1999) . H owever, given the uncertain ties in quantifying the ca use and effect relationships for some ecosys te m pro cesses and ca tc hm e nt manage ment an d the impacts on n ear coastal waters, the time fram es for changes to become visibl e and the broad im pact across society, some formal process of ad aptive change and auditin g is esse ntial. Th e refo re, th e adaptive manage ment process is recommended together w ith strategies to overcome reported criticisms. Developing the Adaptive Management Framework The Ad a pti ve Mana gement Framework d eveloped by th e C R C for Coasta l Zone, Estuary and Waterway Manageme nt has evolved from six frameworks that suppo rt improved decision making in coastal areas. These frameworks are: (i) N ati o nal W ater Quality M anagement Strategy and Queensland ac tiviti es in implementing the NWQMS, Ben nett el al., 2002) (ii) D ecision E n vironm ent (Lawrence el al., 2001); (iii) Framework for integrating catchment, waterway and coastal science into planning (Low Choy, 2002); (iv) Framework fo r integrating research and managem ent (0 . B osch, pers comm.) ; (v) Manage me nt Strategy Evaluation (Smith et al., 1999); (vi) Integrate d mon itoring program using LogFrame (R. Johnstone, p ers co m n1.) Indi vidually, these frameworks are guides to improve catchm ent partnersh ips in developing and implementing th eir integrated natu ral resource manageme nt plans. By comb ining the ir strengths into

CRC

Information Collation

Systems Analysis and Vision

Monitor and Review

Core Components â&#x20AC;˘ Process & Fac ilitation â&#x20AC;˘ Evolving Knowledge System

t

â&#x20AC;˘ IImplementation I Figure 1 . Components of t he Adapt ive Management Framework.

an adaptive framework for developing and testing manageme nt actions, there is a greater opportun ity for resource plans to be impl em ented and supported in the longer term . The framework recogn ises that th e National W ate r Quality Manageme nt Strategy (NWQMS) (1994) u nderpins th e Natio nal Actio n Plan for Salinity and Water Q uality and Natural H eritage Trust programs and specifi cally incorporates the con cep t of in tegrated NRM p lans, in cludi n g ta rgets and perfo rmance indicato rs as measures of e ffectiveness. Basin g the fram ewo rk on the NWQMS framewo rk ensures a greater degree of consiste ncy fo r the deve lopm ent and implementa tion of plans at the regional, State and Federal levels. Importan tl y, the links between the N ational Water Quality M anagem ent Strategy and the Adaptive M a nageme nt Framework means the community is less co nfused by a ' forest of frameworks' and , at the sam e time, su pports the likelihood of effic ie ncy and effectiveness of participation.

T h e Adapt i ve Mana ge m e n t Framework (AM F) com prises six basic com pon ents (Figure 1). Th e cen tral component of th e framework co nsists of an agreed process an d an evo lving kn owledge system. T h is involves t he recogn ition of all stakeholde rs, then the building of trust amongst all stake holders about the actions for developi ng and imple me nting the plans. le also strives to establish an agreement for a new paradigm of co ntinuing learni ng and e mbrac ing of adaptive manage me nt prin ciples that is instituciona lised w ith in th e co mmu nity, industry and government ca tchmentbased partnership. This process leads co an evolving system for knowledge growt h and capacity buildillg. Th e framework is hie rarchical to allow additional details on the components to be show n , and represents a construct in wh ic h processes, information, decision tools an d outcomes are brought together in a structured and transparent way fo r a d aptive catchment and coana l manage ment. For example, if an agreed

Components of the Adaptive Management Framework .

The six components of the AM F are: (i) agreed process and a n evolving knowledge system; (i i) information collation in which sta keholder and on-going research information are pooled to refi ne the syste ms understandi ng a nd find sol utions ; (i ii) systems analysis and vision for context analysis, broad systems understandi ng and expressi ng community aspirations for their waterways as environmental val ues; (iv) plan making in which management goals and targets are established and social, economic and ecologica l impacts are eval uated to negotiate and defi ne a preferred strategy; (v) implementation of the necessary actions; and (vi) monitoring and reviewing the effects of impleme nt ing t he pl a n against the agreed environmental va lues , ma nageme nt goals and targets . WATER SEPTEM BER 2 002

31


COASTAL process for establishing environmental val ues is, available, then it can be detailed , along with the process to establish water quality objectives and targets. Similarly, modelling frameworks, decision support systems and integrated monitoring programs, if already developed, can be detailed w ithin the AMF to add value. Figure 2 gives furth er details of the steps and the linkages between the components. A range of tools and processes are available or are being developed for each of the steps in the framewo rk to ensure that appropriate outcomes are achieved. The following section provides further details of these five components. Information collation The starting point for an adaptive management framework is to collate and integrate existing scientific and stakeholder knowledge and interdisciplinary experiences (Walters 1986). This dynamic integration of information serves several functions, including a broader context of the proble1n or planning opportu nity; identifies knowledge links as well as gaps, and develops better commu ni cation between scientists, managers and other partners. Pooling information so that it is accessible to all partners is a key step towards building trust. Information systems that support synthesis and evaluation of information lead to the framing of effective solutions that are transdisciplinary based (rather than adopting a single point of view). The outcome should portray a known base of essential social, environmental economic information w h ich is known, credible , objective, accessible and suitable for purpose. Systems analysis and vision This component in the Adaptive Management Framework is focused on identifying the institutional environment a nd the stakeholders who w ill be impacted by any decision, gaining a broad understanding of the catchment systems (see below) and then engaging their representatives in a process to define their vision and aspiratio ns for the catchment . A numbe r of participatory processes and engagement tools may be used, including adaptive environmental assess1nent and management (AEAM) and techniques defined in the CRC Ci tiz e n Science Toolbox (See www .coastal.crc. org.au/toolkit). These aspirational statem ents of environmental values would need to be consistent with the institutional environme nt including current legislation , corporate an d

32

WATER SEPTEM BER 2002

CRC

- - ..

I

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Impacts OK

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Figure 2. Steps and linkages in the Adaptive Management Framework

strategic plans for industry, catchment coordinating bodies and government agencies. Conceptual understanding of environmental, social, economic interactions and impacts H av in g d efined the ecosystem, functional, institutional and political boundaries of the catchment, the e mphasis of the Adaptive Management Framework moves to better understand and synthesise the biophysical, economic, social, cultural issues of the catchment. In formation fr om stakeholders and scientists may be used to develop conceptual and dynamic systems models of influences and causal loops between key components. These models may be relatively easier for biophysical components than for economic and social components, although the recent work by Chaloupka et al. (2001) offers new insights to the dynamic linking between ecological and economic facto rs. In addition, this step within the AMF necessitates an exchange and understanding of the mental models held by the partners. Such an undertaking facilitates a convergence of detailed goals to meet society's desires and val ues for the assets to be preserved. Plan making The plan making phase of the AMF establishes and co n so lid ates the management goa ls and targets, identifies potential solutions to the pressures on the system, assesses and evaluates the social, economic and ecological impacts of the alternatives and results in a negotiated

preferred strategy. A range of impact assessment techniques are utilised during this phase of the framework so that data and information are transformed into usable knowledge that lead to strategic positioning and potential solutions. These techniques would include simulation modelling, multiple objective decision suppmt systems, visualisation of catchment scenarios and social and economic impact assessment techniques. In addition, deliberative qualitative methods such as citizen jurys, can play a strategic role in understanding impacts and choosing a preferred course of action (Robinson et al., 2002). The outcomes from this step of the AMF are agreed goals, targets and management actions that are developed from a base of multi-sourced, transdisciplinary information and knowledge. Implementation The movement from a position of identifying a preferred management plan to implementation and large-scale field experimentation reflects a major commitment in the partnership of an adaptive management framework. Apart from the physical arrangements for initiating a change in management actions, the implementation step includes the establishment or reinterpretation of relevant codes of practice, guidelines, licences, permits, institutional changes and in1proved governance based on expectations and responsibilities of all stakeholders. Furthem1ore, it is important that the preferred strategy details the roles and responsibilities of all stakeholders to support the management actions.


COASTAL

Monitoring and reviewing T his step in the AMF comprises two parts. First, the impacts of the catchment plan are gauged using the agreed system of monitoring. T his may involve spatial and temporal evalua tion using an integrated monitoring program. The results are compared with the agreed targets fo r management actions and water quality, to ensure the comm unity's expectations for environmental values are being satisfi ed. In addition , the information is continuously pooled to update the shared knowledge base and informed decision making position of the partners. In th e second part, outcomes from the monitoring are subsequently used to determine whether any updating of system und e rstanding, revision of environmental valu es, goals or targets and / or interventi on of management actions is required. This may involve large-scale ca tchment experimentatio n actions in order to achieve the agreed goals and targets.

Future activities Th e Adaptiv e Man age m e nt Framework described is currently a work in progress and based on current experiences o f Coastal C R C staff (e.g. SEQR WQMS [2001]). Activities are now in place to operationalise the fram ewo rk so that catchment planners can use it as a guide in their planni ng activities. This is bei ng done in two stages. First, an extensive review of CR C researchers' knowledge and the World Wide W eb w ill identify examples of activities th at de monstrate whole or partial steps within the AMF. This will allow potential users to explore in more de tail those aspects of the framewo rk that show its val ue w hen applied to a practical situation. In the second stage, an interactive website is being developed that will link the components of the AMF, associated tools and the web examples to a single site. U sers of the site will be encouraged to provide feedback on their experiences in using the AMF as a parti cipatory planning and management guide. Conclusion With the NAPSWQ (and possibly N HT2) about to enhance the way in wh ic h resource m an age ment and planning is undertaken within Australia, there is a need for holistic approaches that facili tate the development of partnerships and centralise environn1ental, social and econo mic considerations. The Adaptive Management Framework (AM F) utilises

CRC

a number of other structured approaches, including the National Water Q uality Ma nagement Strategy, to suggest an improved way for industry, conununity and government sectors to participate, develop and review coastal resource plans. At the core of the AMF is the recognition that agreed solutions come from an evolving learning-based model in which the acquisition and sharing of kn owledge is used to continuously review and evaluate the implemented management actions. Other steps in the AMF include processes and too ls for syste ms analysis and unders tanding; defi ning an agreed set of goals, o bjectives and targets for the catchment; using all available sources of infor mation and experiences to identify a preferred management strategy that co nsiders a balanced approach to ecological, social and economic requi rements; plan implementation , and monito ring and adaptive cycle of review and respo nsiveness. In practice, the Adaptive M anagement Framework provides an initial guide for

multi-sectoral catchment planning groups that are working towards improving capacity as well as achieving environmen t al outco m es . A web- based development of the AM F w ill soon be available that supports the development of effective and efficient actions fo r resource planning. References Australia and N ew Zealand (ARMCANZ) and t h e A u stra li an an d New Zea la nd Environment and Conservation Council (ANZECC). 1994. National Water Q uality Management Strategy, Policies and Pri11ciples - A Refere11ce Dowmerl/. Canberra, Australia: 37pp. BenncccJ, Sanders N, Moulton D , Phillips N, Lukacs G, Walker K and R edfern F ( 2002)

Cuideli11esfor Prorecri11g A 11s1rnlinr1 Wnren vnys, Land & Water Australia, Canberra, 2002 : 194pp. C haloupka M , R obinson J and Asafu-Adjaye J (2001) Addressing Water Quality Problems through the Integration of Ecological and Economic Modelling, Proceedings o f the Internatio nal Congress for Modelling and Simulation, Canberra 10-13 December: 1031-1036.

Contin ued on page 3 6

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COASTAL

Continued from page 33 G underson L (1999) Resilience, flexibility and adaptive management - antidotes for spurious certitude? Conservation Ecology 3(1) : 7 . [ onl in e] URL: http: //www . consecol.org/vol3/iss 1/ art7. Lawrence P A, Robinson J and Eisner R ( 2001) . A decision environment: going beyond a decision framework to improve the effectiveness of decisio n making in natural resource management. Proceedings of the International Congress for Modelling and Simulation, Canberra 10-13 December: 1613-1618. Lee K N (1999) Ap p r ais in g ada p tive management. Co11servation Ecology 3(2): 3. [o nline] URL: http: //www.consecol.org/ vol3/iss2/art3. Low Choy D. C (2002) Cooperative Planning and Management for R egional Landscapes, PhD thesis, The University o f Queensland, St Lucia (in preparation). Marshall A (1995) in. Gunderson L H, Holling C S and Light S S (eds.) Barriers and Bridges to Renewal of Ecosystems and Jnstitlltions. Columbia University Press, New York, New York, USA. South East Queensland Regional Water Quality Management Strategy 2001. Smith AD M , Sainsbu1y K J and Stevens RA (1999) Implementing effective fi she ries management systems - management strategy

evaluation and the Australian partnersh ip approach. ICES Journal of Mari11e Science, 56: 967-979. Robinson J, Clouston B and Suh J ( 2002) Estimating consumer preferences for water quality improvements using a citizens' jury and choice modelling: A case study on the Bre mer River catchment, South E ast Queensland. C R C C oastal Z o ne, Estuaries and Waterway Management Working Paper. Walters C J (1986) A daptive Ma11agemem of R enewable Resources. McMillan, N ew York, N ew York, USA. Walters C J and Holling CS( 1990) . Large- Scale M anagement Experiments and Learning by Doing. Ecology, 71: 2060-2068.

Acknowledgements Th e Adaptive M anage m ent Framework has been developed through a series of open discussion workshops and collaboration by researchers and staff w ithin the CoastaL C R C. Their contributions and willingness to develop an integrated framework with linked tools has led to the AMF becoming more than just a concept. W e thank our colleagues: Donna Bany , Ockie B osch, Rob Fearon, John Fien, R on J o hnstone, Don Kerr,

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The Authors Paul Lawrence is a Principal Scientist with the Queensland Department of Natural R esources and Mines, based at the Indooroopilly Sciences Ce ntre, and has a scientific background as a catchment hydrologist and as a decision support systems developer. H e is the Coastal C R C's D ecision Framework Theme Leader. Email paul.lawrence@nrm .qld. gov.au. John Bennett is a Senior Principal Environmental Officer with the Q ueensland Environmental Protection Agency and his role includes a significant contribution to the Coastal C RC. J ohn has 28 years experience with water management ranging fro m water quality modelling and monitoring studies to applying this experience to water quality and catchment management.

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COASTAL

CRC

LONG TERM MONITORING OF ESTUARINE WATER QUALITY: BRISBANE RIVER TURBIDITY T Howes, C Lemckert, A Moss Summary

scra111111g acting as a dominant m1x111g mechanism (Neph, 1996; Dyer, 1997) . A projec t at the C R C for Coasta l Unstratified water columns are observed Zone, Es t uary and Wate r way during the flooding tide (as the result of Management is providing info rmatio n on tidal straining) due co vertical turbule nt the variabili ty of water quality at different mixing caused by salt water being pulled loca tions in the Brisbane Ri ver. Data is over less dense water, however some stratbeing used to help: (I) determine the ificatio n (0.5 to 2 parts pe r thousand salt) effectiveness of waterway ma nagement is observed during ebbing tides when tidal measures designed co reduce turbidity (eg straining does not occur {Hollywood et scormwacer control devices, changes co al, 2001; H owes, 2002) . This imba lance dredging, sewage trea t me n t pl a nt between the flooding and ebbing tide flow upgrades); (2) optimise ex isti ng wate r structure effectively pumps sediment q u ali ty models used for waterway from near the mo uth to the fu rthest ma nageme n t fo r p rovid in g accurate fi eld intrusi.on of ocean salinity, creating a data for remote sensi ng projects, and (3) persistent turbidity maximum chat extends co enhance unde rstanding of signi ficant co the uppe r sale water intrusio n limit, ri ver/estuary processes. with peak tu rbidity levels occurring mid By obtain ing a conti nuous record of estuary. Coastal CRC researche r Dr Tony Howes is a these water quality parameters over a chemical engineer from The University of range of seaso ns, tides and rai nfa ll , stakeStudy methods Queensland. holders wilJ be bette r equipped co assess Salinity, turbidity and tempe rature the ecosystem health of the Brisbane measurements were taken at a si ngle site l\.iver and M oreton Bay. length, with sale water intruding 60 km in the Indoo roop illy Reach of the T u rb idity, salin ity and temperature upstream from the mouth for most of the Brisbafle R iver estuary between October measureme nts were take n every fi fteen year. T hi s m icro cida l est u a ry h as 30, 2000 and November 16, 2001, using mi nutes at a single site in the Brisbane maxi m um spring tidal range of 2 .6 m, a YS I Grant 610 Water Quality Logger. River estuary over a period of chirceenwith va rious dams along the estuary Recordi ngs were taken every fifteen monchs. W ide variations in turbidity were lim iting fresh water inflow co 1-2 m 3/sec minutes at the site, w hich is ideally located du ring most of the year. As a resu lt of the o bserved ove r both shore and long time as it is close co the usual location of the relatively low freshwater inflow and scales, highlighting the difficulty in the turb idity maximu m in the estuary but strong tidal m ixing, the estuary exhibits satisfactory interpre tatio n of m on thly (o r downstream o f it (Cox, 1998). The a partially stratified natu re, with tidal less fre q uen t) snapshots of estuarin e measurements represent water quality. A fie of average instantaneous snapshots of the turbid ity vers us ti dal range was 300 ,---,~--,-~-~-~-~-;::::====::;===~ water around the sensor, IUrbidily (NTU) made du r i n g a period of rather than averaged values. sallnlty·10 (PSU) m in imal sedi ment inpu t into tide helght"100 (m ) T he meter is p ositioned 250 th e estua ry fro m fres h water relative to the water surface, inflows, wi th the best fie found and records at depths of 0.51 /\ 200 I' co be T = -93 .7 + 123 G 0 -74 63, \ ± 0.04 111. Day O was assigned where T is the average turbidity co October 31, 2000 starting {NT U) and G the tidal range ~ 150 at 0 :00 am. T idal heigh ts 1 (111) . The data also assists in corresponding specifically co dete rm i ning the underl yi ng 100 the site were obtained from processes occurring with regard the Department of T ransport. co estua rine turbidity . For the purpose of 50 Introduction exp laining the turbidity 0 .___.__ .,___.,___.,___...,__...,__...,__...,__ _._~ pattern within each tidal cycle, The B risbane R iver estuary 28 28.2 28.4 28.6 28.8 29 29.2 29.4 29.6 29.8 30 it has been assumed chat a tidal (which e mpties into Moreton Day cycle begins j ust after low tide Bay) is located in South Ease Figure 1 . Salinity, Turbidity and Tide Height versus Time, Q ueensland (at 153°E , 27°S). when the estuary water November 28, 2000 - November 30 , 2000. (Day 28 T he tidal section of the estuary velocity is zero and the salinity is approximately 80 km in corresponds to 28/ 11/ 2000). conce n tration is at a

WATER SEPTEMBER 2002

37


COASTAL

CRC

minimum, and ends approxiFigure 2 shows a plot of 600 r---,----,---~---.----;:=========::;-, mately twenty-five hours later, average turbidity and tidal range a~rage turbidity (NTU) tidal range¡100 (m) at the second salinity minimum. for the period of deployment. 500 Figure 1 shows turbidity, salinity For much o f the time, a clear and tide height for a two day correlation between tidal range period during November 2000. 400 and average turbidity is evident. The sa linity signal consisten tly Spring tides produce higher lags be hind the tide height average turbiruty rearungs wl1ilst signal, as th e movement of neap tides lead to lower water in the estuary does not turbidi ty values; chis is due to 200 correspond directly with high changin g estuary ve loc iti es and low tide. during these periods. Spring Minimum turbidi ty levels tides have the greatest tidal occur at the beginning of the range, leading to relatively large cycle, but as the water starts to velocities and greater amo unts 150 50 100 200 250 300 350 Day flow upstream both salinity and of resuspension in the estuary turbidity increase, with turbidity and subsequently the higher Figure 2 . Average Turbidity and Tidal Range versus Time, reachi ng the first m axima close turbidity levels. October 30, 2000 - November 16, 2001. (Day 1 to midway through the flood A significant feature of corresponds t o 1/ 11/ 2000). tide. As m aximum sal inity Figure 2 is that th e magnitude approaches, turbidity drops back mixing caused by tidal straining. These of the turbidity measurements is strongly to a mjnimum value. T he mjnimum value plumes are not observed durin g the ebb influ enced by other factors, sediment of turbidity at the high tide slack often tide. carried into the estua1y from runoff being being slightly high er than that observed the most likely cause. Between Days 95 Long-term trends in turbidity were at th e low ti de slack. T his rapi d drop in l02 (February 3, 2001 - February 10, evident in the p lot o f sa linity, turbidity turbidity observed for a shore p eriod 2001) the average turbidity exceed typical and tide height. Over the thirteen m onth around eac h slack ride is due co particles levels by a facto r of ten. This event was period , significant variati ons in tu rbid ity settling from the surface. During most of found to be associated with a major occurred that were unrelated to th e the tidal cycle, verti cal mixi ng ca used by rai nfall-indu ced freshwater inflow event. position in the tidal cycle but primarily flow-gene rated turbu lence negates the Figure 3 shows the individual average to the tidal range, that is, whethe r it was effect of this settling. tu rbidi ty valu es pl otted against th e spring o r n eap tide. To clarify th is pre vaili ng tidal range from the period As the water flow dow nstream, the relationship, the average turbidity for each 26/9/200 .1 until th e e nd o f the salin ity dec reases wh il e the turbidity tidal cycle was compared with tidal range, deployment period. A non-l inear best-fit increases. At the e nd of the ebbing tide w hich has been defined as the difference curve was chosen w ith th ree parameters a second slump in turbidity occurs and is between the highest and lowest va lu es of the form, T = a+bGc, where Tis the generally more pronounced th an that at over fo ur consecutive high/ low tides. The predicted average turbidity (NTU), G the the end of the flood tide. Again, the average turbidity is defined as the average tidal range (111), and a, b, and c fitting turbidity minimum occurs after the tidal turbidity over the period of four high/ low parameters. When this fi t was mad e, T = n1injmum and at the same time as a salinity tides in wh ich the tidal range bas been -93. 7 + 123 co.w,3 , shown as the solid extreme; th is sequ ence of turbidity calc ulated. lin e in the fi gure. Fitted turbidities extremes also occu rs for the d uri ng the p e riod of second flood and ebb tides. deployment range from 22 This was the dominant 150 ,---- - , - - - - - - . - - - , - - - - - . - - - - r - - - - r - - - - , - - - , NTU to 144 NTU for turbidity signature for the corresponding tidal ran ges of period of deplo y ment 0 .92 111 to 2.42 111. These (H owes, 2002). resu lts show how sensitive

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In general , the tu rbidity signal co rrespo nding w ith the flood tide has greater varia nce than that correspondi ng with the ebb tide. The o b se r ved va ri ance patterns are consistent w ith observations taken in th e estuary; during flood tide, considerable spatial variatio n of turbidity and large-scale circulation occ urs, where p l umes of sediment- rich water are d ispersed through th e water column by vertica l

38

turbidity is to the tidal velocity, (and consequently, the bottom shear stress fo r resuspension) and h ighlight bow significant the baseline turbidity varies through the tidal cycle.

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Figure 3 Turbidity versus tida l range, 26/9/2001 - 15/11/2001 . The blue line shows a best fit curve, T = -93. 7 + 123 G0 -7463, wh ere T is th e predicted turbidity (NTU), and G the tidal range (m).

WATER SEPTEMBER 2002

Data collected in the study of the Brisbane River estua1y showed that turbidity levels for much of the year are close ly co rre lated wit h estua1y tidal range, as this determi nes tidal flow veloc-


COASTAL

ities that in turn drive the resuspension o f bottom sediments. Maximum turbidity levels are associated with the most rapid tidal flows, with a rapid decrease in nea rsurface turbidity (for short periods) occurring during slack water. Th e large variati ons in turbidity observed (bo th within a tidal cycle and also from neap co spring tide) point to the extreme difficulties associated w ith interpretation of the results from the usual monthl y who le-estu ary monitoring programs. The large variance observed in th e turbidity signal during the flood tide was the result of tidal straining chat ca used denser downstrea m wate r to flow on top of li ghter upstream water. Acknowledgements The long t e rm dep loyment site has been admini s ter e d by the Queensland Environm ental Protect ion Age ncy. Tide heights were supplied by the Queensland Department of Transport. Th e research was fund ed by Stage 3, M oreton B ay a nd C atchment Partnership , and the C R.C for Coastal Zone, Estuary and Waterway Managem ent.

CRC

The Authors Dr Tony Howes is a Senior Lecture r in th e Environment Engineeri n g Division of the Sc h ool of Engineerin g, Th e University of Queensland. H is resea rch focus is on th e transpo rt and mixing of fluids, solids and contam inants in natural and constructed environmental syste ms, especia ll y relatin g to co hesive materials. Dr Charles Lemckert's degrees were in the fie ld of physical oceanography from the Uni versity of Sydney and in 1993 he obtained a PhD in the field of environ mental fluid dynamics from the Centre for Water R.esearch , Uni ve rsity

of Western Australia. Presently he is a Senio r Lectu rer teach ing and researching in th e areas of coastal dynamics and water treatment processes at the School of Engineering, Griffith University Gold Coast Campus . Andrew Moss is a principal environmental officer with the Queensland EPA. H e has bee n wo rking in the W ater Qual ity area since 1974, fi rstly with the W ater Quality Counc il of Queensland and, since the 199 0s, w it h t he Queensland EPA. H e has a wide range of ex perie n ce with wa ter re late d te c hn ical iss u es an d management strategies.

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References Cox M E ( 1998) C he111iol and Turbidity Character of the Tidal Bri sbane R..ive r , Moreton Bay. in Tibbem I R., H all NJ and Dennison W C (eds) .\ lorct,111 Bay a11rl Ca1d1111c111, Schoo l of Marine Science, The U n iversity of Queensland. Brisbane pp I 75184. Dyer K R. ( l 997) Estuaries: A physical inrroduction. 2nd Edition. Wiley and Sons, England. Hollywood S, Lcmckerr C J. H owes T and Nui111an L (200 I) Suspended Sediment D ynamics in a Hi ghly M odified Microtidal Estuary, Proceedings of Coast and P orrs, Gold Coast . Queensland. Australia, 2628 September 2001, 517-522 H owes T (2002) Riverine Turbid ity Processes Final R eport, Stage 3, South East Queensland R egional Water Quality Management Strategy Neph H M (1996) lnrratidal variations in strntification and mi xing in the Hud son Estuary. Jo1mrn/ Geophysical R cscnrr/1, 101 , 12079-12086.

WATER SEPTEMBER 2002

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COASTAL CRC

WET WEATHER SEWAGE OVERFLOW ABATEMENT PROJECT: LOTA CREEK PILOT STUDY P Pollard Summary

The Coastal Zone, Estuary and Waterway Management (Coastal CRC) has pooled its collective multidisciplinary expertise w ith Brisbane City Council (BCC) in an Effluent M anageme nt project to determine the impacts of wet weather sewage overflows on p ublic and ecosystem health. This paper o utlines a pilot study in the waterways of the coastal suburb of Lota, a residential catchment in Brisbane C ity.

Upstream water quality

,.,.~

Down stream water quality influenced by sewage overflow

Introduction

Sewerage systems in Australia are designed with wet weather overflow structures chat d isc harge into loca l waterways when the capacity of the sewer is exceeded. Their pu rpose is co prevent untreated sewage backing-up and ÂŁlowing into people's homes and onto private property. W et weather overflows are mainly caused by the infiltratio n of water into the sewerage system du ring heavy rain falJ to a point w here the hydraulic capacity of the system is exceeded. Water enters the sewer through the illegal connection of roof and stormwater drains (inflows) or thro ugh poorly sealed access chambers and thro ugh cracked pipes and defective joints (infil tration). Untreated sewage is a m ixture of d o m es tic sewage, in dustria l a nd conm1ercial wascewacers. Its fi nal composition depends on th e activities in the catchment. The overflow often comprises

a)

Figure 1. Sewage overflow structure in the Lota catchment with wet weather inflow and infiltration causing untreated sewage to overflow into the local waterways. Separating the impacts of the overflow from that of the storm water is critical to the success of the project.

high concentratio ns of suspended solids, pathogenic microorganisms, toxic polJuc an cs, floa cables, n utrien t s, oxygen- demanding organic compounds, deterge nts, oil, and grease. Their impact o n the receiving w ater quality may be acute or chronic, affecting water quality, posing risks to human health and the aqu ati c ecosyste m , and potentially impairing the public use of the waterway. However, current water quality guidelines

b)

c)

1

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are based primaril y on ph ysicochemical, rather than biological indicators and do not accurately assess th e pu blic or ecosystem health risks associated with sewage overflows. Also the parameters used for compliance with regulatory guidelines are not sufficient to separate the stormwater impacts from those of an overfl ow nor do they give us the ability to follow the sewage pulse through waterway (Figure l).

Receiving Water

___ 1:_: _)?._ ___ _ Receiving Water

Figure 2 . The impact of the wet weather overflow must incorporat e three events (a,b,c) and also separate the impacts of the stormwater from those of the overfl ow both in time and space. This is achieved by sampling the overflow, the receiving water upstream and down stream of the overflow during rain (a), when there is no overflow with rain (b) and when there is no overflow and no rain (c).

40

WATER SEPTEMBER 2002


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We are addressing the difficult issues of event sampling, sourcing and tracking the untreated sewage in the receiving waters while developing the tools to assess the impacts of overflows on their receiving waters. Here I describe the project's innovative research approach and some preliminary results.

CRC

Emergency sewer overflows of Lota

Project objectives Wet weath e r se wage overflow concerns are common and the Efflue nt Management project aims to 'Research the

ecological a11.d p11b/ic health i111pacts of 111e/ weather sewage ove,j/011Js 1 initially in a pilot s tudy of L ota C r ee k, Brisbane ' . Specifically we want to use eX1st111g m e th ods to measure microbiological, physica l and c hemical water quality to assess the risk to human and ecosystem health. At the sam e time we aim to devel op an innovative ' too l- box ' of technologies to ide nti fy, quantify and track sources of human pollution in the receiving waters. In the pilot phase of the project our motive is to und ersta nd overflow impacts in typical urban streams to h elp BC C provid e m an age m e nt options based on abatement solutions that the community is prepared to accept. The water quality objectives and methods are based on the Australian Water Quality Guidelines for Freshwate r and Ma rine Waters (ANZECC, 2000), BCC W ater Quality Objectives an d those recognised by th e EPA. However, ultim ately we want to establish th e relationship between environmental values and water qua li ty that mea n som ething to th e stakeholders, ie Brisbane C ity Council rate payers. Research Plan

This pilot study is focused o n a single sub-catc hm ent in Brisba ne and relics on short term (12- 18 months) collection of data usi ng parameters based o n:

Figure 3 . The sewerage system is connected via a simple steel flap-value to a dedicated stormwater pipe that directs the overflow into the nearest waterway. Electronic devices attached to the flap-valve continuously monitor and alert the project leader to overflow events while flows in the stormwater pipe and waterway are also measured.

• Environmenta l va lu es (including those set by BCC for this planning unit) • Wate r qualit y of the rece ivin g waterways • Co mposition of sewage in the Lota ca tchme nt • l~obust spatial and temporal sampling design • M ethods available to assess mi cro bial, nutrient and toxicological risk The sa mpling plan disti ngui sh es th e impact of the wet weather overflow from that of th e wet weather event itself by sa mpling the overflow, the receiving water ups tream a nd downs tream of th e overflow, during three different weather and overflow conditions (Figure I and Fi gure 2). • W et weather with overflow

• Wet weather without overflow • Dry weathe r with ou t overflow The research is divided into fo ur tasks: T ask I. Charac terisation of the Sewage in the Lota catc hment T ask 2. Effluent Pathways and Ecosystem H ealth Task 3. Management Options Task 4 . D ecision Support and Public Pa rticipation Th ese four tasks are interdependent. Each relies on the other to generate information to m ove the proj ect fo rward. For example, the components o f the sewage in th e study catchment were first identified and quantified. T he parameters that we are monitoring in the waterways were chose n on the basis of the compon ents o f

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CRC

Figure 4 . The field laboratory is essential for wet weather sampling, initial preparation of biological samples for tran sport, monitoring equipment and the local/central storage of sampling equipment. Graphic design by Queensland College of Arts (QCA) Griffith University has deterred graffiti 'taggers'. the sewage. Kn owing the composi tion and concentration o f the components of the se wage and the hydrau li c loads in the receiving water also allowed us to assess th e potential hazard of an overflow event. With this data we can begin to formula te manage m ent options based o n existing environmental values and guidelines for the receiving waters (Task 3 is linked directly to the o utputs ofTasks 1 and 2) . Task 4 will provide tec hn ical input to the development o f the deta iled decision support system. Th is task will deve lop appropriate multi -objecti ve decision making fram eworks to detem1ine effective sewage overflow managem ent options and resolve conflicting resource uses. In this way environmental planning and resource manage ment options are rigoro usly and transparently assessed using the knowledge gained in Task 1 and 2. H owever, the community participate in setting the water quality standards. The value placed on the environm ent will be determined by th e

cost to engineer solutions - put simply, what ratepayers are prepared to accept fo r sewage management optio ns. Methods The Lota catchment is an urban coastal e nviro nme nt, so u th east of Brisbane's C BD. Lota C ree k is the main waterway through the Lota catchm ent. Tingalpa Creek, in R edland Shire, is the main wa t e r way in t h e adjo inin g catchment to th e south. Both Lota and Tin galpa C reeks meet in an estuary of Moreton Bay. The Coastal CRC project focus is on the lowest lying sub-catchment of Lota (defin ed by BCC planning unit LT /010), a predominantly residential area. One of the b iggest challenges to the proj ect is separating th e impact on microbial and nutrient water quali ty of the u rban stormwater from that of th e overflow itself. The proj ect is simultaneously determinin g when an overflow occurs, the frequency, volume and the rate

that sewage and the rainfall run off enters the waterway. This is critical ifwe are to assess the risk to hum an and ecosystem health related on ly to the overflow event. To m eet th e above challenges we have deve lope d an in n ovative alert and monito ring system for th e rece iving waterways and overflow structures (Figure 3) . T hese are now o perating on all the ove rfl ow structures in the Lota study catchment. The system uses alerts and loggers positioned at the Lota C reek overflow outlets to de termine the angle o f th e flap- va lve and warns the project leader when an overflow occurs. Flows in Lota Creek and important tribu taries are being monitored as well as the ove rfl ow pipes. R ainfa ll is be in g monitored usin g six rainfall ga uges in the catchment while in the receiving waters p H , dissolved oxygen , temperature and conductivity are continuously m easured and logged. Each of th ese parameters can be checked remotely at any time .

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Once the project leader is alerted to a flap-va lve opening, he remotely initiates a sampling routine. The routine starts with the triggering of autosamplers in the receiving waterways, he then runs checks with BCC chat the overflow is not due to a sewerage system fai lu re. When su re chat the overflow is due only co che wee weathe r event and cons id e rin g t he weather pattern, he mobilises a ' tactica l respon se team' (TR T) to sa mple Lota Creek and its tributaries. This ensures that th e sp read of the untreated sewage throu gh the catc hme nt can be capcurcd and m o nitored. O ur initial tri als of the syste m and sampl ing routine showed that the auto-sa mple rs cou ld be triggered within a few minutes of an overflow event w hile the TRT were mobi lised to sam ple the waterway within 60 min of the alert. The re was also sufficient time to recharge the auto-sample r carousels with clea n sterile sa mple bottles wh ile the filled autosa mpler bottles were taken to the field laboratory fo r processing (Fi gure +). As the TR T co llects sa mples t hey arc immediately taken bac k to the o nsite field laboratory (Figure 4) fo r initial processing for microbial water q uality, nutrients and toxicants. This laboratory is a 'pre lovcd' refrigerated shipping container w ith out t h e refrigeration unit (2 .4111 x 6111 x 2111).

CRC

~ wener10~ Industrial D ata Communication Products

Dr Peter Pollard taking water samples from a creek near the sewage overflow in the Lota catchment.

Inside the laboratory the temperature va riation is ± 2°C. W e have installed benc hes, sinks, mains powe r and lig hti ng to ensure on site rapid processing of bio logical water quality testing at any time of the day or night. The field laboratory

Table 1. M icrobial water quality of Lota 's untreated Sewage. Samples were taken from the 'Wet-Well ' during peak flows. The analyses were carried out as per t he recommended methods of the 'American Public Health Association ' and also by Queensland Health and Scientific Services. Total bacterial numbers were determined using epifluorescence microscopy according to Pollard and Greenfield (1997).

Microorganism

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Bacteria

Unit

Lota Sewage

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Total Number of Bacteria cells per ml Faecal Coliform CFU per 100ml CFU per 100ml Escherichia coli Faecal streptococci CFU per 100ml Enterococci CFU per 100ml Clostridium perfringens _ [spores per 100ml Pseudomonas aeruginosa[cFU per 100ml St~phylococcus aureus CFU per 100ml per 1L Salmonella spp per 1L Vibrio cholerae

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98 300 35 35 000 000 1 300 600 000

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per 1L per 1L

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is also an important secure and dry storage area for fi eld samplin g g ear and monitoring equipment. The QCA's Fine Arts department at Griffith University incorporated the theme of the project (Figure 4) in the art covering the shipping container. Their work is appreciated by the local residents and has earned the respect of the local graffiti taggers. Results and Discussion T he first of the four project tasks listed above have been completed. We found constituents of the sewage were consistent with the land use of Lota 's catchment typically domestic. Pesticides and herbic id e s , ph e nol s a nd chlorinat e d h yd ro c ar b o n s were eit h e r b e lo w detection, or below the ANZECC (2000) trigger values. However, some metals and estrogenic hormones have been fou nd at biologically active concentrations in Lota's sewage and therefore they are being monitored in the receiving environment. The wet weath er event will dilute the sewage both in the sewerage system and in the waterway; o ur project will determine the degree of this dilution. However at this stage of th e study, we have fou nd that more than half of the

organi c matter present in the sewage in dry weather is in the form of particulate organic matte r, with the turbidity measurement an order of magnitude greate r than recommended by th e ANZECC (2000) guidelines for aquatic ecosystems in estuaries and low land rivers. In creases in particulate matter in aquati c ecosystems have the potential to adversely impact the waterway downstream of an overflow in two ways. The first is by reducing the light and limiting primary production (algae and cyanobacteria). The second is related to human health. Pathogenic bacteria and viruses adhere to particulate organic material. This makes them more stable in the water column than their free-floating planktonic counterparts. However, in terms of future management options this observation is very valuable. It suggests that removing the particulate material from th e eilluent at an overflow stru cture would halve the organic material as well as removing th e more stabl e adsorbed pathogens. D etermining the value of removing this particulate material from the u ntreated sewage will be a valuable ou tcom e of the proj ect.

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CRC

Microbial Indicators of water quality Many different microorganisms have been show n to be involved in waterbo rne disease outbreaks. Jt would be impossible to routinely test for every viral, bacterial, fun gal or protozoan pathogen that represents a risk to human or ecological health. Apart from both th e cost and the immense resources required, the diversity and complexity of the methods make it impractical (Moe 1997). Water quality objectives are usually based on monitoring indicator organisms which represe nt the behavioural and survival characteristics of potential pathogens (W H O , 1998 ; Baker and Herson 1999; Ashbolt et al. , 2001 ). E. co/i/enteroco cci indicators, persistent spo r es fr o m th e fae cal bac t er ium, C /ostridi11111 pe,fringeus and coliphages are often used to indicate the possible presence of the hardier enteric pathogens (Ashbolt et al. , 2001). Th erefo re, w e are m o nitoring these indicator organisms in th e receiving waterways of Lota to model the survival of pathogens and assess the public health risk. Table 1 compares the types of indicator organisms we found in Lota's sewage with those on e can expec t. Most pathogen indicators were fi ve to six orders of magnitude greater than the World Health Organisation (W H O) M icrobiological Water Quality guidelin es (2001 ) and the AN ZECC (2000) for recrea tional use and also the Water Quality Objectives set b y BCC in 200 1 fo r Lota C reek (faecal coliforms) . The release of wastewater co ntaining pathogens into the receiving waterway is o f pu blic health concern because co nce n tra tions o f indicato r organisms in overflows are usually greater than 106 per 100 ml , as is the case fo r Lota's untreated sewage (Table 1). Dilution into the receiving water is rarely suffi cient co elim inate th e potential risk (Mo ffa 1990). E. coli are a subset of the thermotolerant (faecal) coli fo rms and the preferred group (WH O 200 1) to indicate faecal con tamin ati o n fr o m wa rm- bl o oded animals, including hu mans. T able 1 shows that faecal indi cators exceed guidelin e values set for recreational waters and primary contact fo r Brisbane City Council. B C C's g uideline for mi crobial water quality parameters for ecosystem protection and visual recreatio nal value is faecal coli forms at 1000 organisms per 100ml. For recreatio nal or prima1y contact the limit is 150 organisms per 100 ml. T able 1 shows Loca's sewage exceeds this limit by between fi ve and six o rders o f magnitude under dry weather conditio ns. T o m eet the guidelines fo r Lota C reek the receiving waters must


COASTAL

assim ilate th is high microbiological load rapidly through either dilution or decay in a wet weather event. Most of the physical and chemical characteristics were between one and two orders of magnitudes greater than the rece ntly released guidelines set for aquatic environment by ANZECC (2000) . These parameters have a greater potential fo r dilution down to accep table concentrati ons in th e receiving waters during a wet weather event. Coliform counts are set down as the basis of the regulacory guidelines for microbia l water qua lity. H owever, in the research context o f thi s project we need m ore se nsiti ve and spec ifi c pa ramete rs to follow human co ntamin ation in the rece iv ing water. H uman stcro ls are proving to be a reliab le means of separati ng the faecal coliforms of hum ans from that of other warm blooded an imals (Leemi n g, 1996; L eemi n g et al., 1996;1998) . Leeming (CS I R O, H obart) is applying these methods in this pi lot study to show a similar ability . In dry weather sampling of our study catchment th e main so urce of co liform contaminati o n in the receiving wa ters has been

CRC

herbivore in ong111 (there are horse paddocks in the study catch ment). Thi s observation would not have been possible if we had only used coli forms as indicators of hum an faeca l contamin ation. Conclusion The rate of diluti on of the overflow due to rainfall is going to play a major role in d etermining co nce ntrations of the pathogens and che mica ls in th e receivi ng wa ters of Lota Creek. In a wet weather event, untreated sewage will be diluted by stormwa ter enterin g the sewer as well as w hen the effi uent e nte rs the waterway. The results of o ur study highli ght the importance of quantitative ly measuring the volum e and flow rate of the effi uent leaving the overflow structure and the rate of d ilution in the receiving waters of Lota. Quantitatively measuring these parameters is a major resea rch foc us o f Task 2 . We are developing innovative technologies for an in-field 'tool-bo x' that ca n be used to sa mple , trac k and sou rce indi vidu al overflows. This innovative resea rc h is essenti al beca use the re arc no m ethods to un equivocally identify sources of faecal conrnmination, nor are th ere methods that allow the tracking of pu lses of sewage

entering a waterway. This w ill be accompanied by quantitative assessment of the longer-term spatial and temporal risk assessment and impacts of nutrients, pathogens and tox ican ts on public and ecosystems health. This pilot study of Lota wi ll be com pleted by the midd le of 2003, assuming there is sufficient rain to cause overflow events this comi ng summer. Participants

T h is is collaborative multidiscip linary project involving, Brisbane C ity Council, G riffi th Un ive rsity, CS lRO Marine Research, N atu ral R esources and Mines, CR.C for Water Quality and Treatment, T he University of N SW , The U ni versity of Queensland, Queensland Environ m ental Protection Agency and Queensland H ealth and Scientific Services. Acknowledgements

T his project is funded by the Coastal C R.C and Brisbane City Cou ncil. Specia l than ks to the tactical response tea m members who are call ed om at shore notice to work lo ng hours at all hours of the day and nigh t. We appreciate the c ri tica l com m ents of Ass . Pro f. N. Ashbolt (U ni NSW) in earlier reports.

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The Author Dr Peter Pollard (p.pollard@mailbox. gu.edu.au), is a Senior Research Fellow in Environmental Engineering at Griffith University. Peter is the project leader of the Coastal C R C's Effluent Management and the Sewage Overflow Abatement Project. O ver th e last 20 years his research has developed and applied innovative methods to describe the dynamics and fundamental role of microorgan isms (algae, cyanobacteria, bacteria and viruses) in aquatic ecosystems in coastal zones, Livers, lakes and biological wastewater treatment process. References American Public Health Association (1995) Standard Methods for the Examinatio n of W ater and Wastewater, 19th edn. APHA, AWWA, Water Environmental Association, W ashington, D C. ANZECC (2000) Australian and New Zealand G uidelines for Fresh and M arine Water Quality - Volume 1, The Guidelines. Australian and New Z ealand Environment and Conservation Council, and Agriculture and R esource Management Council of Australia ad New Zealand. In 'National Water Quality M anagement Strategy; No 4'. Ashbo lt NJ, Grabow W O K and Snozzi M (2001) Indicators of microbial water quality.

CRC

In 'Water Quality - Guidelines, Standards and Health: Assessme nt of risk and r isk management for water related infectious diseases'. (Eds: Fewtrell, L. and Bartram, J.) Published on behalf of the World H ealth Organisation by !WA Publishers, London, England pp 289-316. Baker K H and H erson D S (1999) Detection and occurrence of indicator organisms and pathogens. W111er E1111iro11111eut Research 71:530551. Bitto n G (1994). Wastewater Microbiology. WileyLiss, Jo hn Wiley & Sons, Inc, New York. Leeming R (1996) Coproscanol and related sterols as tracers for faecal contamination in Australian aquatic environments (Australia) . PhD Thesis, Canberra University, Canberra, Australia. Leeming R., Ball A, Ashbolt N and Nichols P D (1996) Using faecal sterols from humans and animals co distinguish faeca l pollution in receiving waters. Water Research 30, 28932900. Leeming R., Nichols P D and Ashbolt N (1998) Distinguishing sources of faecal po llution in Australian inland and coastal waters using sterol biomarkers and microbial faecal indicators. CS IRO Report 98-WSAA and Water Services Association of Australia Report No. 204. Report prepared for the Water Services Association of Australia Nov. 1998. Lo ng J and Ashbolt NJ (1994) 1\1/icrobiological

Quality of Sewage Treatmelll Plaut E.ffl11e111s.

A 1ÂĽT Scie11ce & E1111iro11111e11t report 1111111ber

94/123. Sydney Water Corporation, Sydney. Lucena F, Araujo R and Jofre J (1996) Usefulness of bacceriophages infecting Bacteroides frngilis as index microorganisms of remote faecal pollution. Water Research. 30(11), 2812-2816. Moe C L ( 1997) Waterborne transmission of in fectious agents. In 'Hurse C.j., Knudsen G.R., Mcinerney M J, Stetzenbach L D, Walter M V (eds) Manual of Environmental Mi cro biology' . American Society for Microbiology Press, Washington, D C, pp 136-152. Moffa P E ( 1990) Control and Treatment of Combined-Sewer Overflows. Van Nostrand R einhold, New York. Pollard P C and Greenfield P F (1997) Measuring i11 sit11 bacterial specific growth rates (Âľ) and population dynamics in wastewater. Water Resenrcl,. 31 (5), 1074-1082. W H O (1998) Guidelines for Safe R ecreational Waters - Water Environment Drinking Water Quality, Vo l 1. Coastal and Freshwa ters. (D raft for co nsu lta tion. W H O /EOS/98 . 14) . Wo r ld Health Organisation, Geneva. W H O (2001) Water Quality - Guidelines, Standards and H eal ch: Assessment of risk and risk management for water related infectious diseases. (Eds: Fewtrell L. and Bartram J.) Published on behalf of the World H ealth Organisation by IW A Publishers, London, England.

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GROUNDWATER: CAN WE AVOID THE MISTAKES OF THE PAST? TC Harmon Abstract

(M T BE), in o rder co boost pe rfo rmance an d produ ce This paper re vi ew s many cleaner au tomobile e missions â&#x20AC;˘ urban wells existing and several e m erging rural wells in sm o g- p lagu e d regio ns, 80 prob le m s assoc iated w ith su ch as Southern Californ ia. g r o undwa t e r q u a lit y T h ese compounds have been managem e nt. Altho ugh most added co gasoline mixtures in of the examples c ited are from a m o unts r a n g i ng fr o m the U .S.A, man y of these ro u gh ly I O co I 5% (by problems are com mon in ocher volume). W hile air qualiry has d eve loped regions, or w ill improved no ticeably over probably be so in th e near th e past decade, surface and 20 future . gr o un dw a ter qua lity has Introduction su ffe re d greatly fro m th e wi despread introdu ction of 0 Gro un dwat e r 1s a n solvents, fuel aromatics oxygenates fumigants MTBE . M T B E is qu ite refrigerants u nde niably va luable resource, solu ble in wate r (rough ly especia!Jy in arid and semi-arid Figure 1 . The prevalence and similarity of vo lat ile organic 43,000 mg/ L compared co c l i m a t es w h e r e aqui fe rs chemical (VOC) detections in urban and rural wells (adapted ben zene's 1800 mg/L) and provid e th e m ost re liabl e from Squillace et al. , 199 9). t he refo re produ ces larger water supp ly . c onta mi na nt plu mes . be in vio lati o n o f federal law if it Many o f groundwacer's a ttractive Co incid ental re leases from a leak ing contai ns a co ntaminant level exceeding its featu r es also re nd e r chi s r esource unde rgroun d storage tank at a fueling vulne rable co m an 's acti vities, firstly, the M C L. sta tio n and ruptured distributi o n pipe line release of co ntaminants. Seco ndly , the Wh il e th e US EPA mandates and led to the closi ng o f both o f Sa nta long reside n ces and large storage capacenforces environme ntal and hu man health M onica's m u11icipal dri nking water supply iti es translate to lo ng-term contamination pro tectio n fro m poll u tants, it is the U .S. well fields . T he drinki ng w ater supply fo r problems . Thus, co ntam ination ch at has G eological Survey (USGS) that is cany ing the entire population (85,000) is now gon e unno ticed for many years m ay o ut th e N a tion a l Wa te r-Qua li ty im ported, at the expense of the respo nrequire deca des o r longe r co rem edi ace . Assessment (NA WQA) Program of more si ble petro leum co m pa ny. T his case provides a clear wa rning if urban plan ning than SO promin e nt hydrol ogic system s. Groundwater Monitoring and neglects co accou nt for grou ndwater N A WQA groundwate r assessm ents co Regulation in the U.S.A. protectio n. dace have included pestic ides (Kolpin er Groundwater resource management in M etals such as lead, arse n ic , and ri/., 1998), vo latil e organi c che mica ls, o r the USA is overseen primari ly by state and chro miu m are o f co ur se no n VOCs (Squillace et al. , 1999) and nuc1ients local agencies. One exceptio n is that in biodegradable and meta llic species can (Nolan and Sto ner, 2000; Nola n et al., matters oflarge-sca le contamin ati on , the lin ger indefi n itely in ground water. M ost 2002) . U S E PA typica lly ove rsees characteriindustrial eilluencs are controlled but zation and mitiga tio n of the hazards Major Groundwater Pollution large-sca le releases o f high ly m obi le involved . State agenc ies are o nly at Sources arsen ic, chromium and o ther metal hbe rcy to e n fo rce mo re stringent regu lacontaminants can and do occur. Th e most Industrial Sources. Fu el co ncamin acion t1ons. infamous example in the U .S. A was a case is most rampant in groundw ater. In 1997, Federal drinking water qualiry standards in volvi ng the re lease o f ch ro mi um there were ro ughly 330,000 co nfirmed are co ntrolle d by th e U S EPA and are doped coo ling water co unlined ponds ac lea king u nde rground storage tanks in the ge n e ra ll y e nfor ce d by sp ec ify i ng a la rge power p la nt in H inckley, U .S. A (USEPA , 1997) . Fuel constitue n ts max imum allo w able conta min ant levels Cali fo rnia . T his tainted the grou ndwater of grea test co nce rn arc benzene, to lu ene, (M C Ls) . M ost M C Ls are driven by lo ngsupply of the residents and resu lted in a ethylbe n zen e and t he Jo, -ylenes . (BTEX). term exposure and chroni c risk (e.g., large lawsuit agai nst the power company, T hese co mpo unds, particul arl y b enzene, can ce r) co nside rati ons, and are therefore w hic h was chronicled in t he motion are the most soluble (i.e., mobile) and pose q uite low. Be nzene, fo r exa mple, has an pictu re " Eri n Brockovich" . the greatest risk co humans. The relati vely M C L o f 5 pares per b illion (ppb or ~1g/ L). C hlo r in a t ed sol ve nts , s u c h as biodegradabil ity o f most low risk and T hus, groundwater may be considered co p erc hl o r oeche n e ( P C E ) a n d o cher hydrocarbo ns helps co mitigate their T his is an edited version of a paper presented crichloroethene (TCE), once used fo r dty impact on groun dwater. H o wever, in the at the R.MIT/ UC LA Workshop in March 2002 clean ing and degreasing, have caused the lace 1980s, the petrole um industry intro(see page IO of the August edition o f W ater most w idespread contam ina ti o n in th e du ced an array of fu e l oxygenates, th e Jo1mrnl). U .S. A. They are no w ubiquitous at low m aj o r o ne b eing m ethyl ce rt- bu tyl e th er 100 , - - - - - - - - - - - - - - - - - - - ~

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WATER SEPTEMBER 2 0 0 2

47


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levels in both urban and rura.l groundwater (Figure 1). The same properties which made these solvents attractive to industry, hydrophobicity and recalcitrance, are at the root of costly groun dwater problems (Harmon, 1999; K hachikian and H armon, 2000) . H ydrophobi city translates to low water solubility, mean ing that even sma ll subterranean releases of the chemicals are capable of creating vast contaminant plumes . R ecalcitrance translates co plume longevities ranging from decades co centuries, depending on the volume of so lvent released and the natu re of the m itigation effort. Leaki ng underground solven t storage tan ks as well as careless disposa l of spent so lvents h as resu lted in greater Los Angeles being listed as a "Supe rfund" si te (see Harm o n , 1999). T he TCE plum e depicted in Figure 2 is on e of several overlapping chlorinated solvent plumes in the alluvial aqu ifer underlying chis region. It is roughly 25 km lo ng, 5 km wide and perhaps 50 co 100 m in thickness. These dim ensions suggest that over three trillion gall o ns of groundwater is tainted beyond the M CL fo r TCE (3 ppb). Fu rth ermo re the problem is relatively permanent, given ch at there are doubtless many hundreds of gallons of neat solvent remaining as ongoing sources in the ground . These sources are diffirnlt to pinpoint in heceroge n eo us geology (Khachi k ian and H armon, 1999; Scio rtino el al. , 2000), and will continue to feed the plume u ntil located and removed. T he current strategy for th e San Fern ando Va ll ey grou ndwater basin is known as pump- and-treat. Produ ction wells pumping at roughly 25 M L/d began captu ring the grou ndwater in late 1999, and co nveying it co a ded icated treatment

San Gabriel Mountains

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Agricultural Sources. The risk from the careless application of pesticides and herbicides to grou ndwater depends on the type and amount of application, crop-type (coverage), cl imatic conditions a nd, perhaps most importantly, th e soil conditions and depth co grou n dwate r . Ho weve r, NA WQA pesticid e data demonstrate chat, in general, heavily treated cropland tends to produce a high incidence of groundwa te r co ntaminatio n (Kolpin et al., 1998) . For example , for crops like w heat and alfalfa, atrazine application is very low (less than 0 .05 kg/km 2) and the freque ncy of detection in groundwater was found co be correspondingly low . However, in crops w here acrazine had been regu larl y applied in loads of greater t ha n about 2 kg/ km 2 , t he

plant (ai r stripping with off-gas treatment by carbon adsorptio n). T he e n tire effort, from site c haracterizat ion to the construction, operation and ma intenance of the treatment plant, wi ll cost hundreds of millions SUS, for what would oth erwise have been wasted groundwater. Fortunately, the USE PA contracted with the city of G len dale, C A to rece ive the product for blending into its potable water supply. Serving water from a "hazardous waste site" was probably considered impossib le by most water agencies in the U.S.A until recent years. H owever, the combinatio n of popu lation pressu re, water scarcity and increasing confidence in treatment tec hnologies have redu ced th is issue co one of cu ltivatin g pub lic acceptance thro ugh risk comm un ication.

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frequency of detection was greater than about 35%. Kolpin e1 al. (1998) do report exceptional cases w here lesser applications resulted in greater frequency of groundwater detection and where high loading fai led to produce high frequency detection. These cases may be attributed to si te- specific effects (e.g., soil cond itions), such as those reported below for nitrogen fert ili zer. Nitrogen and phosphorous fertilizers arc another potential source of groundwater contamination . In the U.S.A. the application of these fertilizers increased g r eatly over th e last h alf-ce ntury. B etween 19-U and 1993, nitrogen ferti li zer application increased roughly 20fold to approximate ly I 0.3M metric tons p er year while phosphorous fertilizer app li cation more than tripled to about 1. 8M metric tons per yea r (Puckett, 1 995) . Both come from point sources (e.g., wastewater treatment plant effiuent) and nitrogen comes from the atmosphere but these cont1ibutions arc much less than those associated with agricultural applications (see Figure 3) . As th e va lues for nitrogen loading in Figure 3 suggest, there is a large discrepancy in applications between differe nt regions of the U.S.A.

For example, the San Joaquin Valley in California enjoys a longer growing season and app lies significan tly greater amounts of fert ilize r and manure per year than do other regions. Whether or not nutrient loading is excessive from the sta ndpoint of groundwater contam ination is another question. A recent NA WQA-based effort probed for the presence of nitrogen and phosphorous fertilizers in 20 groundwater units beneath both urban and agricu ltural land usage, as well as in major aquifers (Nola n and Sto ne r, 2000). R egulato ry levels for phosphorous in groundwater arc not well-established. The key concern is the cutrophica tion of groundwate r-fed streams and lakes. Fo r nitrogen fertilizers, the major concern is nitrate (N03¡) due to its known human health risk, pa rticularly for infants. Th e maximum al lowab le leve l fo r nitrate in the U.S.A. is 10 mg/L. Nolan and Stoner found that median nitrate concentrations ranged from 0.-18 mg/L in deeper maj or aquifers, to 1. 6 and 3.4 mg/ L, respecti ve ly, in urban and agricu ltura l shallow aquifers (defi ned as 5 111 deep or less). As the plot in Figure 4 suggests, n itrogen leve ls in grou ndwater cannot be pred icted from

nitrogen loading alone. As one would expect, local hydrology and the specific soil types separating the surface from the aquifer must be considered before determin ing nitrogen loading limits in a region (Nolan and Stoner, 2000). In the San Joaquin Valley for exam pl e, heavy nitrogen loading together w ith shallow, alluvial groundwater systems results in relatively high nitrate concentrations. In contrast, nitrogen loading is even greater for the Rincon Va ll ey in New Mexico, but the extremely high evaporation rate and lack of precipitation in this region produce relative ly low nitrate levels in groundwater. Human Waste Sources. On-site waste disposal operations, such as cesspools, septic tanks, and open trenches can act as sources of pathogen ic and other contaminatio n of groundwater. Mexico City exemplifies th is potential problem perhaps better than anywhere with its large popu latio n and its network of unlined sewer canals, and deep drainage system overlying its over-taxed aq uifer system (Mazari and Mackay, 1993). The same problem plagues most of our urban envi ronm ents as our elaborate sewer infrastructure begins to age and leak. The

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WATER SEPTEMBER 200 2

49


WATER

solution to this problem (replacing or retrofitting existing sewer systems) will be extrem ely expensive. Septic tank systems are common in rural areas of developed nations. The poten tial fo r shallo,w grou nd wa t er con tamination by such systems is significant. Scandura and Sobsey (1997) studied four septic systems situated in sandy soils of the coastal plains of North Carolina. They fo und that seasonal rises in the water table res ulted in relatively frequ ent groundwater co ntamination episod es. Risks of viral contaminati on were fou nd to be greatest in coarser, relati vely high pH (6.0 to 6.5) soil zones and in the wi nter time, when th e water table was m ost elevated and the temperature lower. The transport and viabili ty of viruses into deeper groundwater is not well-u nderstood, and is being researched. T his issue will play an important role in determining the viability of emerging processes like artificial groundwater recharge using recla imed wastewater effi uent. Natural Sourc es. Natural prob lems in groundwa ter include seawater intrusion an d the m ore recentl y di scovered occurrence of heavy metal contamin ation

under relatively common hydrogeochemical conditions. Seawater intrusion is a constant problem where coastal groundwater basins are being tapped for water supply. Poor m anagem ent o f groundwater reserves in these basins will quickly exacerbate the problem by reversing the natural hydraulic gradient by which fresh groundwater flows toward the ocean. T he mechanics and management of seawater intrusion are well- understood. In terms of practice, the Orange County Water District since 1976, under pressure from substantial population growth, been inj ecting reclaim ed wastewater into a series of 23 injection wells four miles inland to form a water mound , blocking encroachme nt o f seawater. Secondary treated effiuent is subj ected to a careful polishi ng process that culminates with m embrane filt rati o n. This level of treatment may be considered excessive in view of th e large distances between the water production wells and the coastal barrier wells. H owever, there at least two sound justificatio ns. Fi rstly, the best way to combat pu blic percepti o n is to simply clean the water to potable level prior to

The National Centre for Groundwater Management INCGMI at UTS is recogni se d by the Federal Governm ent through LWRRDC as a National Centre for Training, Resea rch and Co nsultancy in Groundwater and Environmental Applications. A comprehensive range of HECS-based po stgraduate programs is currently offered: • Master of Engineering and Master of Science !Co ursework - full or part -timel • Graduate Diplomas !Engineering or Science !full or pa rt- timel • Master of En gin ee ring and Master of Sc ience !Research - full or part- timel • PhD !Full or pa rt -ti meI • Gra duate Course 115 weeksl Areas of study in the coursework subj ects include: • Groundwater Contam inant Tra nsport Mode lling

50

WATER SEPTEMBER 2002

111Jectio n into the ground. Secondly, population pressure in Southern California and similar heavily urbanized locales will continue to exert pressure on regional water resources. T hus, water district m anagers will quite conceivably com e to rely more on recycled wastewater to artificially recharge water supply aquifers. This emerging issue will be discussed fu rther in the fo llowing section. Naturally occmTing metals, particularly arsenic, can seriously damage groundwater quality. Arsen ic- contaminated water in India, Banglades h,Taiwan and other regions has already caused serious health problems (NRC, 1999; 2001). Arsen ic is u biquitous in the soils and aquifer sediments of the U.S.A. especially in the western states (Welch et al., 2000) . The sou rce of th e arsenic in th is case is the mineral matrix comprising th e aquifer or its boundaries. Thus, it is a permanent problem, mitigated on ly by permanent treatment facili ties or abando nment of the aqu ifer as a drinking water su pply. Alth ough less of a hea lth concern , natural sources of chro mium also appear to be commonplace in aquife rs com prised of certain types of sili cate minerals. T he

• Quality and Quantity Optimisation Strategies for Water Reso urce Developmen t • Waste Management and Groundwater • Co ntam inated Land Evaluation and Rehabilitation • Bore Fouling and Main tenance • Practical Areas of Hydrogeology • Land and Groundwater Salinity Courses are flexible, with options in full-time !block model. part-time !block model, and by distance mode. Like to know more? For information an d applicati ons contact Professor Michael J Knight, Director, National Centre for Groundwater Management, UTS, PO Box 123, Broadway NSW 2007 Au stralia. think.change.do. 02 9514 1984 Fax: 02 95141985 Email : groundwater.management@uts.edu. au Website: http://groundwater.ncgm.uts.edu.au/ncgm/

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discovery of roughly 20 ppb hexavalent chromium levels in a Mojave Desert groundwater basin has given rise to a hydrogeochemical investigation of this system in the face of a proposed aguifer storage and reco very project. The proposed project will deliver water from the Colorado R iver Agueduct (one of several water lifelines currently supplying Los Angeles) to the desert aguifer during wet periods, and reclaim the water during dry periods . However, if the chromium-free Colorado River water was to commingle with the tainted desert aquifer water, and state or federa l standards on chromium were to be lowered to below the current state standard of 50 ppb total chromium, then th e project might incur additional costs to reduce the chromium species. At the time of th is writing, however, there appears to be no conclusive j ustification for a lower chromium standard (Flegal et al., 2001).

Emerging Problems Emerging groundwater problems stem from increasing population pressure. Prominent examples in the U.S.A are the

pharmaceutical and endocrine disrupting chemicals which have been discovered in surface and groundwater systems. The source of these chemicals is our municipal wastewater (Sedlak et al., 2000). T heir presence should come as no surprise given the preponderance of these chemicals in our medicine cabinets (e.g., pain relievers, hormonal treatments, etc.) and our food supplies (Guenther et al., 2002). The levels at which these chemicals have been identified are generally low, in the parts per trillion range. H owever, the ir widespread presence serves as a warning as to the vulnerabiliry of our groundwater supplies, particularly in arid regions where a great reliance on artificially recharging groundwater with recycled wastewater is inevitable. A more general emerging problem concerns developing methods for incorporating groundwater resource protection into integrated watershed management. A new type of standard called the total maximum daily loading (TMDL) has arisen from the U. S.A's C lean Water Acc. Under this law, impaired waters must be identified, and TMDLs mu s t b e developed for poll utants ca using the

impairment. While most attention is currencly being paid to streams and rivers, it is only prudent to incorporate groundwater into this type of analysis as well. While there are clearly fewer habitatrelated issues associated with groundwater impainnent, we have seen too many times already that the conseguences of groundwater contamin ation are long-term and expensive to mitigate. Once TMDLs or similar regulatory vehicles are the norm, the cha!Jenge wi lJ be to develop large-scale and dense monitoring networks . Sensor maturity, wireless technology and embedded networked sensing (ENS) strategies may allow us to meet this challenge within the next ten to twenry years. Successful dep loyment of ENS wi!J facilitate early warning aga inst groundwater contaminatio n , a practi ce tha t would be substantially more economical th an remediation after the fac e.

Conclusions Th is paper summarizes many existing and several emergi ng problems associated with groundwater quality manage ment, including co ntam ination from hydro-

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WATER

ca rbons (fuels and solvents), m etals of industrial and natural origins, agricultural ferti lizers and pesti cides, human and livestoc k waste, pharmaceuticals and endocri ne disruptors. Although most of the examples cited are from the U.S.A. many of these problems are common in other developed regions, or will probably be identified in the near future . Given the many attractive water supply features of gro undwater, it is critical that water agencies manage groundwater resources judiciously. Contamination episodes are much more costly and diffi cult to mitigate in groundwater than in other water in1pou ndments. Thus, remediation of contami nated aquifers should be carefully prioritized and reclaimed water shou ld be utili zed to the extent possib le. T his latter issue w ill require carefu l risk communication to alleviate customers' concerns. In addition, future groundwater contamination should be avo idab le, but will requ ire integration of surface water and groundwater ma nageme nt strategies. Such integration would be greatly assisted by the development of reliable and shared water quality databases (at local, regional

and national scales). These databases can guide the deployment of new types of embedded, networked monito r ing systems in wh ich the emphasis is id entifyi n g and preventing poten tia l groundwater contamination .

The Author Thomas C. Harmon is an Asso ciate Professor in the Civil and Environmenta l Engin eering Department at the University of Ca lifornia, Los Angeles. H e c urrently serves as Chair of the Environm ental Engineer ing academ ic progra m . He teaches undergraduate courses in water and wastewater treatment, and in contaminant hydrog eo logy. Email tharmon@. ucla.edu

References Flegal R, Last), McConnell EE, Schenker M, Witschi 1-1 (200 I) Scientific R eview of Toxicological and Human Health Issues Related to the Development of a Public H ..:alth Goal for Chromi um(V l), Report to Ca li forn ia Environmental P rotection Agency's Office of Environmental H ealth Hazard Assessment (O EHi-iA). Guenther I< V, H einke V, Thiele B, Kleist E, Prast 1-1 and R.accker T (2002) Endocrine Disrupting Nonylphcnols Arc Ubiquitous in

Food, E1111iro11111e11tal Scie11ce & Tec/1110/ol)', 36 (8), 1676- 1680. Harmon TC (1999). "Groundwater Qualiry", in So11thern California E1111iro11111e11tnl Report Card /999, R Berk and AM Winer (Eds.), UCLA Institute of the Environment. Khachikian C S and Harmon T C (2000) Nonaqucous Phase Liquid Dissolution in Porous M edia: Curren t State of Knowledge and Research Needs, Trm1sport i11 Poro11s Medin, 38( I / 2), 3-28. Kolpin D W, 13arbashJ E and Gilliom RJ (1998) Occurrence of Pesticides in Shallow Groundwater of the United States: Initial Results from the National Water-Quality Assessment Program, E1//liro11111eutal Scie11ce & Tec/1110/i\~)', 32 (5), 558-566. Mazari M and M ackay D M ( 1993) Potential for Groundwater Contamination in Mexico C ity, E1111iro1111ie11tnl Srie11re & Tcc/1110/o,~)', 27(5). 794-802. National Research Council (NRC), ( 1999). Arsmir i11 Dri11ki11,Q l1Vnter, National Academy Press, Washington, D.C. Natio nal R esearch Council (N l<..C) (2000)

/i111cs1ignti11,~ Gro1111d//lc1tcr Systems 011 Ri.:~io11al ,111d Na1io1wl Sen/es, National Academy Press, Washington. D.C. National R cs..:arch Council (N R C), (200 I)

A rm1ir i11 Dri11ki11,~ IVntcr: 200 I Update, National Academy Press, Washington, D .C. Nolan 13 T and Stoner J D (2000) Nutrients in Groundwaters of the Conterm inous United States, 1992-1995, E11,,;,-,,,,11,mtnl Scie11ce & "frr/11wlo.~y, 34(7) , 1156- 1 165. Nolan B T, Hitt I< J and l<..uddy B C (2002) Probabili ty of Nitrate Conccmration of Recently Re charg ed Aquifers in the Conter111inous United States, E1winJ11111e11tnl Scie11re & Tec/11wlogy, 36( I 0), 2138-2145. Puckett LJ ( 1995) Identifying the Major Sources of N utrient Water Pollution, E11viro11111e11tal Scie11ce & Tec/1110/0.~Y, 29(9), 408A-4 14A . Scandura J E and Sobscy M D (1997) Viral and Bacterial Contamination of Groundwater fi-0111 On-Site Sewage Treatment Systems, Wat,â&#x20AC;˘r Scimre a11d Tec/11wlogy, 35(1 1-12). I 41146. Sciortino A, Harmon T C and Yeh W W-G (2000) Inverse Modelling fo r Locatin g Dense N onaqueous Pools in Groundwater Under Steady Flow Conditions, Wnrer R.eso11rces Research, 36 (7), 1723-1736. Sedlak D L, Gray J Land. Pinkston K E (2000) Contaminants in l< ..ecyclcd Water, E1111iro11111c111al Srie11re & Tec/1110/o,~y, 34 (23), 509A- 5 15A. Squillace P J , M oran MJ, Lapham WW, Price C V, Clawges R M and Zagorski J S ( 1999) Volatile Organic Chemicals in Untreated Ambient Groundwater o f the United States, 19 8 5 - 1995, E 11 11iro 11111eutnl Srieuce & Tcr/1110/o,~y. 33(23), 4176-4187. U.S. Environmental Protection Agency ( 1997)

Stm(~/11 Talk 011 Ta11ks-Lend Dctertio11 ,\/ethods .for Petrolm111 U11dergrc11111d Storage Timks, EPA 510-13-97-007, Office of Underground Storage T anks, Washington, D.C. Welch A 1-1, Wesrjohn D 13, 1-lclscl D R , Wanty R 13 (2000) Arsenic in Ground Water of the Uni te d States: Occurrence and Geochemistry, Cr()Jmd Water, 38(4), 589-604.

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WATER SEPTEMBER 2 002


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ENVIRONMENT

ENDOCRINE DISRUPTION: AN AUSTRALIAN PERSPECTIVE G-G Ying, RS Kookana Abstract In recent years the re has been an increasing concern in both the general publ ic and scien tifi c communi ty about e ndocrine disrupting che mi cals (E D Cs) due co the possible impact of even very low levels on wildlife and human health. H owever, ma ny questio ns remai n co be answered before the scale and risks co humans and ecosystems can be established. Au stralia is lagging behind Europe and N orch Ame rica in e ndocrine disruption research an d n eeds co take a proac tive approach cowards the endocrine disrupco rs iss u e . Owing co the li mited resources, the re is a need co focus on certai n selected sec to rs and sources suc h as dom estic sewage efflu ents and industrial wastewater as well as co ntaminants from intensive agriculture and m in ing activities. Th e enviro nme n tal fate of EDCs under th e Australian co nditi ons sho uld be a hi gh resea rch priority fo r Australia , and this paper presents a short review of the current state of knowledge.

made amendme nts co the Safe Drinking W ater Ace (SOWA) in 1996 and required th e United States E nv ironm e nt a l Protection Agency to develop a screenin g program for endocrine disrupcors (Fe nnerCrisp et nl., 2000) . In April 2000, a m eeting of the enviro nme nt ministers of the G S group of in dustrialized cou ntries listed EDCs as one of the high priorities and ca ll ed for a furth e rance o f kn owledge acquisiti on on ED Cs thro ugh jointly planned and implemented projects and in ternational information sharing (Loder, 2000) . Surveys of so me new em erging endocrine di sruptin g chem ica ls (e.g. nonylphenol and stero ids) in majo r rivers of some co untries have been undertaken (e.g. N aylor et nl., 1992; Blackburn et nl., 1999; Ahel et nl., 2000; T abaca et nl., 2001). The U S EPA and the Organization of Economi c and Cooperative D evelopment

(0 ECO) have invested consid erable resources co develop ti ered procedures for the testing and assessment of EDCs (Fe nner-Crisp et nl., 2000; H uet, 2000; Parrott er nl., 200 1) . T he U S EPA planned co screen 15,000 chem ica ls for the ir possible effects as endocrine disruprors in animals and humans (Macil wain, 1998). U p co now , little research has been done o n endocrine disruption in Australia; the refo re it is necessary to identify kn owledge ga ps and determ ine research p riority areas. We have cond ucted an extensive review of curre nt knowledge, backed by more than l 30 references. The full version in a PD F fil e is available from the correspondin g author (G-G Y ing). Endocrine system Alo ng with the nervous system, the endoc rine syste m is one of the two

Keywords: Endocrine disruptor; human; wildlife; ecosystem; Australia. Introduction T here is a concern that some natural and synthetic chemicals can interfere w ith the normal fun ctioning of endocrine syste ms, thus affecting reproduction and develo pm e nt in w ildlife and humans. These chemica ls are called endocrine disruptors or endocrin e disrupting chcrnicals (ED Cs) . Although endocrine disruption has been known since the 1930's (D odds et nl., 1938), this issue has regain ed attention and generated immense scientific and public inte rest since 1992 (Colborn and C lement, 1992) and especially since the publi cation of the book 011r Stole11 F11t11re (Co lborn et nl., 1996). Wildlife and humans are exposed daily to these pervasive c hemicals that have already caused numerous adverse effects in wi ldlife and are most likely affe cti n g humans as well. There is compell ing evidence on the effec ts of exposure to endocrine disrupting chemicals on wildlife. H owever, except in a few cases (e.g. diethyl stilboescrol) a causal relatio n be tween exposure co che micals and adverse health effect in humans has not b ee n firmly established. U S congress

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ENVIRONMENT

com municatio n systems that regulate all responses and fu nctio ns of the body . Hormones are bioch emicals that are produced by endocrine glands in one part of the body, travel through the bloodstream and cause responses in other parts of the body. They generally fall into four main categories: (1) amino acid derivatives, (2) proteins, (3) steroids and (4) eicosa noids (Lister and van der Kraak, 200 1) . The unifying nature of ho rmone actio n is the presence of receptors o n target cells, which bind a specific hormone with high affin ity and stereospecificity. Some hormones act by entering target cells and stimulating specific genes. All other hormo nes bind to recept0rs o n the cell surface and activate second- messenger molecules withi n the target cells. The body has hundreds of different kinds o f receptors; each one is designed tO receive a particular kind of chemical sign al. The ho rm o ne and its receptor have a 'lockand-key' relationship. O nce joined, the ho rmone molec ule and its recepto r trigger the prod uctio n o f' part icul ar proteins that ' turn on ' the bio logical activity associated w ith the hormone. H ormones have two types of acti on: o rgan isati onal and activati o nal (Lister and van der Kraak, 2001). T he fi rst type of actio n occurs d uring critical periods of develo pment and induces permanent effects, such as the acti o ns of sex steroids. The second type of action o nly causes transient changes in a myriad o f cellular processes such as the effects of glucagon and ins uli n o n glu cose ho meostasis. O rganisational actions are more important in terms of effect with respect tO environmental contamin ants (Guillette et al. , 1996).

Endocrine disruption T here are several ways that chemicals ca n interfere t he endoc rine sys tem (Sonnenschein and Soto, 1998) . They can mimic o r block natural hormones, alter hormonal levels and thus affect the fu nctio ns that th ese hormones control. Less direct interferences involve alteration of the body's ability to produce honnones, interference with the ways hormo nes travel through the body and changes in n umbers of receptors. Regardless of the situatio n, having too much o r too little of the hormones it needs may cause the endocrine system to function inapprop riately . Very su btle effects on th e endocrine system can result in chan ges in grow th, development or behaviour that can affect the or'ga nism itself, or the next generation (Guillette et al., 1996; vom Saal et al, 1997; Palanza et al., 1999). At particular times embryos and fetuses are

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Table 1 . List of suspected/known endocrine disrupting chemicals (EDCs) Classification

Pesticides

Endocrine disrupting chemicals

2,4-D

Kepone (Chlordecone )

Atrazine

Lindane

Benomyl

Malathion

Carbary!

Mancozeb Methomyl

Cypermethrin Chlordane (')'-HCH ) DDT and its metabolites Dicofol Dieldrin/ Aldrin Endosulfan Endrin Heptachlor Hexachlorobenzene (HCB) lprodione Organohalogens

Dioxi ns and furans PCBs

Alkylphenols

Nonyl phenols Octylphenols Pentaphenols

Heavy metals

Cadmium Lead

Organotins

Tributylt in (TBT)

Phthalates

Methoxych lor Mirex Parathion Pentachlorophenol Pe rmethrin Simazine Toxaphene Triflu ralin Vinclozoli n PBBs and PBDEs 2,4-Dichlorophenol Nonylphenol ethoxylates Nonylphenol ethoxylates Butylphenols Mercury Arsenic Triphenyltin (TPhT)

Di-ethyl hexyl phthalate Butyl be nzyl phthalate Di-1rbutyl phthalate

Natural Hormones Pharmaceuticals Phytoestrogens

Dicyclohexyl pht halate

Di-1rpentyl phthalate

Diethyl phthalate

Di-hexyl phthalate

Di-propyl phthalate

17~-Estradiol

Estriol

Estrone

Testosterone

Ethinyl estradiol

Tamoxifen

Mestranol

Diet hylstil bestrol (DES)

lsoflavonoids

Zearalenone

Coumestans Lignans

~-sitosterol

Phenols

Bisphenol A

Bisphenol F

Aromat ic hydrocarbons

Benzo( a)pyrene Benz( a)anthracene

Ant hracene

Benzo(b/h)fluoranthene

Phenanthrene

6-hydroxy-chrysene

1rButyl benzene

especially se nsm ve t0 low doses of endocrine disruptors (Guillette et al. , 1996; vom Saal et al, 1997; Palanza et al., 1999). Substan ces th at have no effect in an adult can become poisonous in the developing embryo. The timing of exposure may be more important than the dose. T he ultimate effects of endocrine disruption might not be seen until later in life or even until the next generation (C olborn et al., 1996; U S EPA, 1997).

Endocrine dlsruptors An extensive list of the chemicals (T able 1) (Colborn et al. , 1996; Guillette et al. , 1996; Sonnenschein and So to, 1998; U S EPA , 19 97 ; D e p l e d ge a n d Billningh urst, 1999) that have been fou nd or suspected to be capable of disrupting the endocrine systems includes

Pyrene

many pesticides that are designed to be bioactive (e.g. D DT, vinclozolin, T BT, atrazine), persistent organochlorines (e.g. PC Bs, dioxins and furans), alkyl p henols (e.g. nonylp he nol and octylphenol), heavy me tals (e .g . cadmium, l ead, mercury), phyt0estrogens (e.g. isoflavoids, lignans, P-si tosterol), and synthetic and natural hormones (e.g. 17P-estradiol, e thi nyl es t rad iol) . Man y o f t h e se compounds have little in common structurally or in terms o f their chemical properties, but evoke agonist or antagonist responses, possibly through co mparable mechanisms of action. T hese chemicals are released fro m a wide variety of sources such as intensive agriculture, industrial wastes, mining activity, domestic sewage and landfills. Suspec ted endoc rin e-


ENVIRONMENT

disrupting chemicals can be found in eve1y compartmem of our e nvironment (a ir, water, soil, sediment and biota), in industrial products and house hold ite ms and even in the food we eat. They are often found in mixtures, such as efiluencs from sewage treatment plants, pape r mills and textile factories. l t is not clear w hether the components in a mixcure act additively, synergisti cally or antagon isti cally. Endocrine disrupting chemicals can be classified into the following categories: (1) en v ironmencal estrogens, e.g. mechoxychlor, bisphenol A; (2) environmental a nciestrogens, e .g . dioxi n, endosulfan; (3) environmental anciandrogens, e.g . vinclozo lin, DOE, Kraft mill eilluent; (4) coxicancs that reduce steroid hormo ne levels, e.g. fenarimol and o ther fungic ides, e ndosulphan ; (5) toxicants chat affect reproduction primarily through effects o n the centra l nervous system (CNS), e.g. di chioca rbamate; (6) toxicants that affect hormone status, e.g. cadmium, benzidinebased dyes (D epledge and Billinghurst, 1999). T he chemistty of th e potential e ndocrine disruptors varies greatly, as does potency, i.e. the effectiveness in binding a nd turning-on the response . M ost en doc rine disruptors have very low potency, as their chemisny is significantly different from th e hormones they mimic. In addition to potency, the potential fo r a hom1one-like effect depends on dose. For most of the endocrine disruptors, the doseresp onse relationship has not yet been established, especially at the low dose range, and this may differ from species to species. The risk of endocrine disruptors to humans and wildlife also depends on their behaviour and fate in the environment. Chemicals behave differently in different m edia. For example, nony l ph eno l h ad a dissipation half- li fe of~ l .2 days in the water column, 28 to 10-1 days in sediment and 8 to 13 days on macrophytes in an experimental littoral ecosystem (Liber et al., 1999). Some endocrine disrupting c h emica ls (e.g. DDT and PCBs) are ub i quitous and pe r sistent in the environment (Atlas and Giam, 198 I). They accumulate in the fatty tissue of organisms and increase in concentration as they move up through the food web (biomagnification) . Because of their persistence and mobility, they accumulate in organisms and harm species fa r from their original sourc.e . In order to assess the risks, it is necessary ~o carry out m onitoring of chose chemicals possessing endocrine disrupting characteristics in enviro nmen tal media. The levels of EDCs in the environment around the wo rld will not be reviewed here due to huge in fo rmatio n available in litera ture

and unclear dose-response relationships for most EDCs. Australian perspective Australia is interested in the endocrine disruption issue. The Australian Academy of Science organised a forum "Endocrine disruption: Austral ia's role in an international issue" in April 1998 and pointed out that more research is needed to work out the risks, and the ways that the chemicals affec t humans and w ildli fe, and also the levels which are haza rdo us (Australi an Academy of Science, 1998). Some Australian l ndustty sectors have al ready acknowledged th e publi c conce rn about th e potent ial hea lth effect th ro ugh expos ure to endocri n e di sruptin g chem icals. Sydn ey Water listed e ndocrine disruption as one of the water quality issue in its five-year drinking water qua lity m anage me nt plan (Sydney Wate r, 2000). In the plan, Sydney Water will support resea rc h in this area through its resea rch partn ership arrangements and closely mon itor the r esea r c h co ndu cted worldwide. Th e Inter-govern m enta l Forum of C he mi cal Safety (IFCS), of which Australia is an active member, recognised the serio usness of this issue duri ng Februa1y 1997 meeti ng in O ttawa

and concluded that there is a need to investigate, in depth, the human, environmental and ecotoxicological aspects of EDCs. In fact, there is nothing unique about Australian domestic sewage water, industrial chem icals or pesticides, and the Australian environment is no exception to endoc1ine disruption . Endoc1ine disruption has been reported in Australia, including abnormal reproductive and developmental functions in offspring of women w ho took DES and thalidom ide (Colborn et al., 1996), imposex of molluscs in harbours caused by TBT in anti fou li ng paints (Daly and Fabris, l 993; Kohn and Almasi, I993: Burt and Ebell, 1995), reduced go nopod ium size of male mosquitofish exposed to sewage effluent in NSW (Batty and Lim, 1999), decreased fertility of sheep in WA ca used by phycoestrogen in pasture grasses (Bennetts et al., 19-16; Adams, 1998) and decreased breed ing success of the peregrine falcon in SA being associated with high organoc h lorine residues (Falkenberg et al., 1994) . Although there are few reported cases of endocrin e disruption in Australia compared with the situation in the N o rth America and Eu rope, consideration should be taken to

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reduc ing th e exposure of wildlife and humans to endocrine disruptors in line with the "Precautionary Principle". EDCs in Australian environment

D espite th e few monito ring studies on the new emerging e ndocrine disrupting che mica ls such as alkyl phenols and hormone steroids, there have been some reports on heavy m eta ls, pesticides and PCBs in Australian environment, w ildlife and humans. H eavy metals (e.g. Cu, Pb, Zn, Cd, Cr and Ni) and pesticides (e.g. DDT, DDE, e ndosulfan , atrazine, lindane, chlorpyrifos and simazine) have been detected in Australian riverine environm ents (Thoma, 1988; Cooper, 1996; McKe nzie-Smith et nl., 1994; Birch et nl., 2001). Endosulfan and atrazine were the most commonly de tected pesticides in Australian surface waters. Pesticide contamination of birds and fish in the Namoi Valley, New South Wales (NSW) has been report ed (G ilb ert el nl., 1 990) . Concentrations o f DDT in bird species ranged from 151 to 535 mg/ kg fat, which were much highe r than in other N SW districts (0.04 co 6 .93 mg/kg). Fish species caught withi n the cotton area had significantly high DDT levels and 20% of all fish exceeded the 1 Âľgig N H MRC MRL. Toxic contaminants in marin e mammals coll ected around Australia w ere reported with concentrations of 1.5 to 479 m g/kg for mercury in liver and <0.05 to 3.87 mg/kg for PCBs in blubber (Kemper et nl., 1994). High levels of heavy metals and polychlorinated dibenzo-p- dioxins and dibenzofurans w ere found in dugongs of northern Australia (Denton er nl., 1980; Haynes el nl. , 1998). Th is may link to the population declin e of dugongs in oceans, as they are vulnerabl e to anthropogenic impacts. H eavy metals and organochlorines have been fou nd in sedim ents, fish and invertebrates near sewage ocean outfalls in Sydney (Miski ewicz and G ibbs, 1994; K rogh and Scanes, 1996; Matthai and Birch, 2000). Up to 24 mg/kg ofTBT (dty we) has been reported in coastal sediments of Western Australia and Vi ctoria, w hi ch led to imposex in molluscs (Daly and Fabris, 1993; Burt and Ebell , 1995). Organochl orine pesticides (e.g. DDT, DDE, H CH, aldrin , dieldrin , lindane) and PCBs have been detected in breast milk of women in Victoria (Newton and Greene, 1970; Quinsey et nl. , 1995), Quee nsland (Miller and Fox, 1973), N ew South Wales (Siyali, 1973) and Western Australia (Stacey et n/., 1985). The organocblorin e residue levels in Australian women are co mparab le to those in other developed countries (e.g. Schade and H e inzow, 1998; Ko nishi el nl., 200 1;

56

WATER SEPTEMBER 2002

Newsome el nl. , 1995) and may link to biological effects on the offspring of th ese women Qacobson and Jacobson, 1996; I-foyer et nl. , 1998; Palanza el nl. , 1999) . Priority areas and research needs in Australia Endocrine disrupting chemi cals can be re leased into e nvironme nt from many different sou rces. The following are considered pote ntial sources of EDCs in the Australian environment. Sewage eflluents In Australi a more than 5000 ML of sewage effiuents are generated every day from municipal sewage treatment plants. Most of the sewage effiuents are directl y discharged to aquatic and marine environments and only 11% is currently reused. However, more than 70% ofbiosolids are reused as fertilizer on land, and th e chemi ca ls in biosolids may be persistent, runoff to surface water or leach into groundwater. Sewage effl u e nts a nd biosolids are known to contain various classes of chemicals, of w hich many have been found to be e ndocrine disruptors. Intensive agric ulture Wastes, run-off and spray drift of pesticides have been shown to contribute EDCs to the environment. Livestoc k wastes These contain not only nu trients (N and P) but also pesticides and hormon e steroids excreted from animals. These are significant polluters of the nation 's wate rs. Australian indu stries Effiu ents fro m paper and pulp mi lls discharge into rivers, lakes and coastal e nvironme n t in Au stralia (e.g. van Leeuwe n el nl. , 1993), and may contain c hlorinated compounds (chloropbenols, dioxi ns), surfactants (nonylphenol) and/or phytosterols, w hich cou ld affect fish in the receiving water. Wool scouring uses large quantities of detergents during the process and the waste eilluent contains very high concentrations of surfactants and their degradation products suc h as nonylphenol Qones and W estmoreland, 1998) . H eavy metals from min ing activities have become a problem in some areas, especially in older lead, zinc, copper, gold and sil ver mines (e.g. Norris, 1986). Mine wastes constitute a potential source of contamination to the environment, as heavy metals and acid are released in large amou nts. Contaminated indu strial sites Austral ia currently has o ve r 80,000 contami n at ed s ite s in th e urban environme nt. Th ese sites were co ntaminated with vario us c he mica ls, o f wh ic h many are e ndocrin e disruptors su ch as pesticides (e.g. DDT and DOE), polychlorinated biphe nyl (PC Bs), polyaromatic

hydroca rbons (PA H s), heavy metals (e.g. Cr, Cd, Pb) and arsen ic. Long range transport In addition to local sources, man y c hemicals, espec ially organic poll utants, can be transported from och er places through atmosp he re. M any potential e ndoc1ine disruptoL-s such as PCBs, phthalates, organochlorines, PA H s and heavy metals are ubiqui tous and have been found even in re mote places far from continental sources (Atlas and Giam, 1981). Since N orth America and E urope have invested great amounts of resources in che biologica l effects of ED Cs and screening and testing programs, Australia can easily adopt the ir resea rch results. Australia should fo cus on the fate and behaviour of endocrine disruptors, especially those n ew e m e rging che mi ca l s (e . g. nonylp h enol, bispheno l A, hormone steroids) in the aquatic environme nts due to the importan ce of water resources in Austra lia and possible impacts on wi ldl ife and human health. There are significant gaps in our knowledge of the environmental che mistry of th ese chemicals in aquatic environme nts, including th eir fate , and b i oava il abil i cy in diffe r e nt environme nt compartme nts . The d istri bution of these EDCs in envi ron m ental media and their degradati o n rates under the Australi an conditions should be given a high priority for resea rch because the levels of these che mi cals in the Australian environments may be differe nt from those of North Ame rica and Europe , and their behaviour may also be different under differe nt e nvironme n tal co n ditions. R ivers, marine and coastal environment are two priority sectors to be stud ied . Conclusions The risks of EDCs to Aust ralian populations and ecosyste m s are currently unknown because there has not yet been suffici ent research. It is critical that Australia takes part in international e fforts, such as in OECD's scree ning and testing program, so that interna tionally accepted tests can be adopted in Australia. Due to limited resources and resea rch funding in Australia , the fo cus sho uld be o n t he identification of sources of ED Cs, understa nding th eir levels and behaviour in Australi an environmen ts (especially in aquatic environments), assessing e ffects o n ecosys te ms as well as hum ans, and reducing and / or pre ven ting re leases into the environment. A survey o f EDCs in the concern ed sectors is needed to understand the possibl e exposure extent and risks. Acknowledgements This review was conducted by CS!RO Land a nd W ate r. T h e author s ackn owledge the partial finan c ial suppo rt


ENVIRONMENT

by Land and Water Australia. The authors also thank Drs B. Williams (The University of Adelaide), B. Patterson and P . Dillon (CSIR O Land and Water), and F. Chai (SA Health Service) for their valuable comments. The Authors Guang-Guo Ying and Rai Kookana are research scientists with CS IRO Land and Water, Adelaide Laboratory, PMB 2, Glen Osmond, SA 506 4, Australia. Corresponding author Tel. : 61-08-8303 84 74, email: guang-guo.ying@csiro.au. References Adami, H.0. cc al. (1994) illtcr11111io11nl Jo1mwl ,!{Cnttccr 59 , 33-38. Ahcl. M. cc al. (2000) Wat Sci Tec/111()/ 42(7-8), 15-22. Alzicu, C. (2000) En•toxirnh\~)' 9, 71-76. Atlas. E. and C iam, C.S. ( I981) Scic11cc 211, I63165. Auscr:1lian Academy 01Scicncc ( 1998) . Et1docri11c disn1ptio11: rl11stralic1's mlr i11 ,111 i111rr1111tio1tnl iss11e. National Science & Industry Forum R eport, April 7, I998. pp. 1- 12. (Canberra. Australia .) Batty. J. and Lim. R. (1999) rlrd1it1 E,111iro11 C>11tc1111 ·1c1xicol 36, 301-307. l3c nnctts, H. ct al. ( 1946) A11stmlic111 Vetcri11ar)' Jmm111/ 22 . 2-12. 13it·ch, C. cc al. (200 I) IVntcr, rlir & Soil Po/1,,r 126 (1-2). 13-35. l3lackburn. M.A. cc ,1I. ( I 999) .\/nri111· Poll11ti,111 B11lll'li11 38 (2), I 09- 11 8. l3urt.J.S. and Ebcll. C.F. (1995) ,\/ari11r Pol/111ia11 B11/lrti11 30(11) . 723-732. Co lborn, T. and C leme nt, C. ( 1992) In: Ad1 1n11ces i11 ,\fodcm l:111 1ir,111111c•111t1/ Ti,xiwhi~J', vol. 21. (Ed5 T. Colborn and C. Clement). (Princeton Scientific: Princeton. NJ.) Co lborn. T. cc al. (1996) 011r St,,ll'II F11111rc. (l'lumc/Pcnguin 13ook: New York.) Cooper. B. ( 1996) Ci•111ml c11td l\·onh IVest riJi,111.< I Vi11cr Q11t1/it)' Pnwrc1111. 1995196 Report ,,11 Pc.Hicidc .\/o11itori11.~. I S96. 0-18. (NSW Department 01 Land and Water Conservation: Sydney.) Daly, H. and Fabri5,J.C. (1993) A 11 c1111iro111111•111t1/ study ,!( trib11t)'lti11s i11 Viaoric111 111c1t1•rs. (Environmental Protection Authority. M elbourn e, Victoria, 3000. SRS 90/020.) Denton. C.R. ct al. (1980) .\/nri11c Bi,1/c,gy 57, 207-219. Deplcdge, M. and 13illinghursc, Z. ( I 999) ., lnri11e P()l////io11 B11/lc1i11 39( 1-12). 32-38. Dodds, E.C. cc al. ( 1938) Nnttire 141 , 247-248. Fenner-Crisp, P.A. et al. (2000) Ecowxirolo,~y 9. 85-91 . Gilbert, W. S. et al. ( I 990) Tcd111iml B11/lc1i11.l'\'SIV Agriwlt11re Fisl,eries 40, iv+27pp. Guillette, L.J. er al. (1996) A11i111nl Reprod11aio11 Scie11ce 42, 13-24. H aynes. D. ct al. (1998) Chemosphere 38. 255262. Hoye r, A.P. ct al. ( 1998) 77,c Ln11cct 35 2(5), 1816-1820. Huec, M . (2000) Erntoxicology 9, 77-84. Jacobson, J.L. and Jacobson . S.W. ( I 996) The t,:e111 E11gln11djo11mnl ,?f.\ledici11e 335, 783-789. Jones, F.W. and W estmo reland, D.J. ( 1998) E1111iro11 Sci Tec/1110/ 32 , 2623-2627. Kemper, C. er al. (1994) Sci Totnl E1111iro11 154, 129- 139.

Kohn. A.J. and Almasi. K.N. (1993)Jo11mn/ of ,\/ari11c Biological Associntio11 of UK 73, 241 244. Konishi, Y. et al. (2001) Arc/1i11 E,11,iro,1 Co111n111 Toxico/ 40 , 571-578. Krogh. M. and Scancs, P. ( 1996) ,\/nri11c Pol/11tio11 B11lleti11 33 (7 / 12), 2 I 3-225. Liber, K. er al. ( I 999) E1111iro11 Toxicol Chem 18, 357-362. Lister, A.L. and Van Der Kraak, G.J. (200 1) IV111 Q11nl Res J Cn11 36(2), 175- 190. Loder, N. (2000) Nnt11re 406 . 4. Macilwain. C. (1998) t\'n111re 395, 828. Matthai, C. and 13irch, G.F. (2000) E1111iom Polh11 110, -111-423. McKcnzic-Smicl,, F. ct al. ( 1994) Ard1i11 E,11,iro11 Co11t,1111 Toxirnl 26(4), 483. Miller, C J and Fox, J.A. (1973) ,\ lcdicnlj,lllm,tl of Australia 2 , 261-264. Mi sk iewi cz. A.G. and Gibbs, P.J. ( 1994) E1111ior"11 Pol/11t 84, 269-277. Naylor, C.C. ct al. ( 1992)JIIOCS 69(7), 695703. Newsome, W. r r. ct al. ( 1995) C/11·111MJ1l1cri• 30 ( 11 ), 2143-2 153. Newton, K.C. and G reene, N.C. (1972) Pesticide ,\/o11iwri11,~ Jc111mnl 6( I ), 4-8. Norris, ll.H. ( 1986) Aust) ,\ J,1ri111 & Fres/11t'ttter R1•s 37(2), 146-157. Palanza, P. cc al. ( 1999) t\'c11roscic11cc n11d Biobclte111ior,1/ R c1 1ie111s 23 , I 0 1 1-1027. Parrott, J. cc al. (200 I) r Viu Qua/ ResJ C1111 36(2). 273-29 1. Quinscy. P.M . er al. ( I 995) l'ood & Che111icc1/ Toxiwl 33 ( 1), 49-56. 1

Schade, G. and H cinzow, 13. (1998) Sci Total E1111iro11 215, 31-39. Siyali, D.S. ( 1973) 1\Icdimljo11mnl of A11strnlin 2. 815-818. Sonnenschcin, C . and Soto, A.M . (1998) jo11mn/ ~( Ster()id Biod1c111istry t111d .\lolcwlnr Biology 65(1-6), 143-150. Stacey, C.l. cc al. ( 1985) l lrchi,, E1111iro11 Health 40(2), 102-108. Sumpter,J.P. ( 1998) Toxirnlog)' L('{lm 102/103 , 337-342. Sydney Water (2000) Syd11cy I Vt11cr's 5- ycnr dri11ki11,~ 111nter quality 111n11a,~c111c111 J1la11 (Discussio n paper). Commu ni ty and Stakeholder Consu ltation. August 2000 . (Sydney, Australia.) Tabaca, A. cc al. (2001) IVnt Sci Trc/1110/ 43 (2), 109-1 16. Thoma, K. ( 1988) Pilot s11mcy ~( Jll'Sticidc residues i11 streams drni11i11.~ a hC1rtimlt11ral mtd1111wt, Pirmdilly Vaill')', South A,,srrnlin. South Australian Department of Agriculture, Technical Paper No. 13 1,June 1988. pp. 136. US EPA ( 1997) Special rc·1um 011 e1111iro11111l'lltnl c11docri11e disr11ptio11: A11 1:ffects assess111e11t c111d c111nlysis. EPA / 630/R-96/ 012. February 1997. (U.S. Environmenta l Protection Agency. Washington D.C.) van Leeuwen . J.A. ct al. (1993) rl11st J ,\lc!ri11e & Fres/1111<11cr Res 44, 825-834. vom Saal. F.S. er al. (1997) Pmc 1\'t11/ A(c/d Sci 94 . 2056-2061 .

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II

ENVIRONMENT

ENVIRONMENTAL FLOWS - AN ECOLOGICAL PERSPECTIVE G Quinn, M Thoms Introduction ln recognition of the possible ecological degradation of Australia's river systems, the Counci l of Au stra lian Governm ents (C OAG) in 1994 proposed a water reform framework that recommended that water allocations and entitlements muse be determined for each "system" and recogni zed chat th e enviro nm e nt was a legitimate user of water. Subsequently, a sec of national principles guiding water use has been deve loped . Th ese nationa l prin ciples state, amon g other things, that regulation and consumptive use potentially impact on ecologica l va lu es, that th ere sh o uld be pr ov ision of water for ecosystems to sustain eco logical values, that environm e nta l wate r provisio n s sho uld be lega ll y recognized and that ac tion should be taken to m eet environm ental needs.

Environmental flows Th ese Au s tra lian d e velo p m e nt s occurred at a period when th ere was in creasing recognition of th e need to provide water to the e nvironment to try and reve rse som e of the ecological effects of ri ver regulation. Two terms are co mmonly u sed to describe wate r provided to th e riverine environment. Environmental water allocations usuall y refer to a volum e of water allocated to a specified sectio n of rive r, floodplain or associated wetlands. For example, approximately I 00GL of water pe r annum is allocated, from Hum e D am, to extend fl ooding in wetlands in the B armahMi llewa fo rest o n the Murray R.i ve r. En v ironm enta l flow s are u s ual ly considered as releases of water from storage w ith the following aims: • To restore missi ng components of longer- term natural hydrograph. • To r es tor e n atura l seasonalit y (winter/spring floods). • To improve river (and floodplain) " health ". • To improve (or stop the decline oQ particu lar targe t species, usually fish and/ o r birds. Footnote: This is an edited version of a paper presented at the RM IT/UCLA Workshop in March 2002 (see page 10 of the August issue of WaterJo11mal).

58

WATER SEPTEMBER 2002

In practice, the distinction between an environmental water allocation and an en vironm ental flow has been margina l beca use only small amoun ts of additi onal wate r arc u sually avai lab le for th e environment and the role of flood pulses has bee n considered fun da mental to ri ver ecosystems (the Flood Pulse Concept - see Boulto n & Brock 1999). So environm ental flows have often been conside red in terms of annual allocation of volumes of water, rarely enough to produce overbank fl ows an d re-conn ect the ri ver and its floodp lain. T here is an increasing realisation chat we need to chink in terms of environmental flow regimes that return so me of the natural variability in fl ow patterns tine has disappeared due co regulation . O ne way of achieving ch is is using th e translucent dam approach , w hereby a proportion of water entering a sto rage is passed thro ugh fo r release downstream (Boul ton & Brock 1999) . Such an approa ch provides additio nal water to th e e n vironm e n t and also restores some of the natural va riability in flo w patte rns , especiall y during no nirrigation seasons.

Strategies for environmental flows T h e va ri ous strateg ies for se tting environmental flo ws have mainly been based on providing water and habitat fo r particular species of interest, especially fish. Boulton & Brock (1999) provide a good introduction to these strategies and a more detai led comparison is in Arthi ngco n & Zalu cki (1998) .

Hydrological H ydrological methods, such as the Tennant (o r Montana) m et h od for instream flow assessme nt, use lo ng- te rm flow data co estimate natural flow regimes, under the assumption ch at fish will do better under natural flow regimes. Usually, only a proportion of ave rage £low can be restored so natural variability is rarely considered by th e Ten nant me tho d.

Hydraulic habitat These m ethods are based on the relatio nship between useable habitat for target species (e.g. fis h) and flow. In m ost cases, cross-sectio ns or transects of the

river arc used to map ph ysical variables such as wetted perime ter and use th ese to determine the flows that will maximize available habitat. T he most sophisticated version of thi s approach is the Inscream Fl ow In cremental M eth odology (LFIM), w hich implements predic ti ve models based on field data describing the flo whabitat relati onship fo r particula r species. Simulation software, such as PHABS[M (physical habi tat simulation), is used to simulate the relationship between river flow and physical habitat fo r vario us lifestages o f fish species. On e of the major advances of th e IFIM approach is chat it uses a formal and repeatable methodology and in corporates a fo rm of decision support syste m.

Holistic H o listic me th ods move away from foc usin g on particular species, such as fish, and in corporate river health and the stru cture and functio ning of the riverine ecosystem. There arc various inter-related approaches chat are ca lled holistic. Expert or sc ien tific panels have been widely used in Australia to provide reco mmendations o n environm ental flows (Co ttin gham et al. 2002). They combine ava ilable data o n a spec ifi c ri ver w ith expert opi ni on in hydrol ogy, geomorphology and ecology to de ri ve appropriate flo w regim es. Building Block Methodology tries co build an appropriate flo w regime from th e bottom up by adding particular higher flows and floods to a base flow. T he added flow components are based on knowledge of w hi ch components are important for selected biota or ecological processes. Flow Restoration M ethodology starts w ith the natural fl ow regim e and dete rmines which co mpo ne nts are m issin g in the c urren t flow regim e and which have the highest pri o ri ty for resto ratio n. The DR I FT (Downstr ea m R.es ponse co Imposed Flow Transformations) m ethod is the most holistic of these approaches. It was developed for the Lesot h o Highlands Water Project in southe rn Africa and an alyses the consequ e nces of potential future flow scenarios, based on a biophysica l database established fro m available information . DRI FT fo cuses on quantifying li nks b etween changing river co ndi tio n and so cial a nd economic


ENVIRONMENT

impacts on riparian people who rely on river for subsistence.

Constraints Th e major constraint on setting appropriate environmental flows is our limited understanding of ecological responses co flow modification and restoration. O ur predictions of ecological outcomes when flow regimes are changed are not yet very specific. For example, how do biodive rsity, population sizes of particular taxa, and va rious ecological processes like productivity and nutrient cyc lin g depend on flow regime' Which components of the flow regime are the real drivers of these responses' E ven if we know how much water to release, and what flow pattern we should use, other problems can limit the effectiveness of environmemal flows. First, water bodies in dams often stratify so that the botcom water is very cold. Most dam rel ease valves are near the base of the dam waJJ so environmemal flow releases may be introdu ci ng water much co lder than am bietJC into the ri ver. This cold water pollution can affect many aspects of the ri ver ecosystem, especiall y fish spawning

and recruitment (Sherman 2000). Second, adding water to a river to rescorc some biotic com pone nts of the ecosystem may be unsuccessful because the water docs not inundate suitable habitat for key biota. For example, many fish species rely on woody debris (snags) fo r shelter yet most of our large rivers in Australia have been subject co "de-snagging" . Third, providing small to medium floods sho uld benefit the ri ver system by reintroducing lateral connectivity but if the floodplain and associated wetlands are very degraded (e.g. no riparian vegetation) then these high flows may actua lly cause increased sedimentation and nutrient input into the river channel. Environmental flows, th erefore, must only be one component of a broader restoration strategy that may need co include physica l habita t restoration and specific efforts to improve water quality.

Environmental flow research We can address the major kn ow ledge gap, our limited understanding of the causal links between flow c hange and ecologica l response, in at least three ways. First, we can review the available literature and unpublished datasets so we maximize ou r learning from previous research and

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develop sensible conceptual models and hypotheses for further research. Such reviews can summarise correlations between flow changes and ecological responses, estimate effect sizes (average % change in selected variables) that can be used when designing future field investigations and improve our conceptual models of how flow affects riverine ecosystems. Second, we can use carefully designed sampling programs to monitor ecologica l responses co natural flow events. For example, co mpa rin g key ecologica l characteristics of a river and its floodplain (e.g. aspects of productivity or decomposition, the movement of biota) between different natural flow events (base flow, bank full, overbank floods) across a range of river types wi ll enable us co develop predictive models lin king flow change and ecological outcomes. Fina lly, we should do flow manipulation experiments, at realistic spatial and temporal scales. These experiments, w hich shou ld be linked close ly to management actions such as implementing environm enta l flow regimes, will provide the strongest evidence of causal links between

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59


ENVIRONMENT

flo w changes, especially managed flows, and ecological responses. An example of a flow manipulation experiment is the Campaspe Flow Manipulation Project being done by the CRC for Freshwater Ecology. An environmental flow regime fo r th e Ca m paspe R iver in central Victoria was negotia ted w ith th e water management agency (G oulbou rn Murray Water) whereby 25% of inflows into Lake Eppalock (the major storage) are passed thro ugh when the dam reaches 64% capacity (a "translucent dam " approach) o utside the irrigation season (May October). The relatively " unregu lated" Broken River is used as a combination of co ntrol and r efe rence system. T he ecological responses being assessed include channel form, macroinvertebrates (particularly sh rimp) , larval fish (as a measure of fish recruitm ent) and adult fis h. While this part of Victoria has been in drought fo r the past five years so the dam has rarely reached the trigger level for flow releases,

th e proj ect has greatly increased our knowledge of fis h in lowland rivers, including the hypo thesis that low flows can be important fo r fish recruitment (Humphries et al. 1999).

Measuring success Environmental flows sh o u ld be conside r e d a fo rm of ecosyste m restoration. H obbs & Norton (1996) highlighted the key processes required for successful restoration. These in cluded: • identifying and reversing the degrading processes (hydrology), • setting realistic goals (restoration targets), • ha v ing cle ar measures of success (indicators), • monitoring key system variables and adjust resto ration procedures if necessa ry (adaptive management). Co mpared to setting en viro nm ental flows, much less effo rt has been allocated to d esigning appropriate mon itori ng

progra1ns to determine the eco logical success of these flows, i.e . have we progressed towards or reached our targets? A mon itoring progra m fo r evaluating environmental flows will have the same fund am e ntal co mp o n en t s of any monitoring program assessing the effects of human activities, whether they be degrading or restoration (Downes et al. 2002, Quinn et al. in press) . W e need a conceptual model th at su mmarises our ecological understanding of the ecosystem, a flo w-response m odel that links flow regimes with geomorphic and habitat responses, initial survey data to develop monitoring d esign para m ete rs and determine statistical power, and a set of va riables and indicators that represent key biota and ecosystem processes . Most importantly, we need to determ ine the spatial and temporal components of our design, including control systems (comparable rivers t h at do not receive en viro nmental fl ows) and reference

BOOK REVIEWS Assessing the F11t11 re: Water U tility Iufrastmcture Management by David Hughes. Published 2002 by A WWA ISBN 1-58321-1 28-4 RRP $260. Available from AWA by email: bookshop@awa.asn.au Infrastructure comprises the essential networks that make sure that big cities and larger conm1muties are able to function and are supplied with their essential needs. Telecommunications, the postal service, road, rail and air transport systems are all classed as infrastructure. Water is an essential good and water infrastructure - the above ground and under ground network of water distribution and wastewater collection systems of pipes, pumping stations, hydrants, storage facilities - ensures that consumers are connected to, and receive water from the public system and are able to discharge waste water fo r centralized treatment and disposal. Such an important asset needs to be mainta ined in o rder to ensure that consumers at the end of the distribution system receive water of the highest quality and without egress of microorgan isms, contaminants and su ndry deposits either for dri nking , commercial or agricultural end-use. The network must not suffer failu re due to breaks, equipment seizure, internal corrosion and deterioration over time. But how to identify when, where, and the extent of infrastructure wh ich is not performi ng well, needs replacement or has broken and corroded? H ow best can infrastructu re be m a na ge d to g uar a nt ee minimum 60

WATER SEPTEMBER 2002

disruption and at minimal cost to all and w ith an eye to th e future? Assessi11g the Future: Water Utility Infrastructure Man agement by D avid Hughes seeks to answer these questions and to do so with an eye on best practi ce futu re m anagemen t. Th ere are four ma in sections. The first deals with strategic approaches for corporate water utilities in US and Europe models and their differen ces . Life cycle an alys is is n ow recognized as a central tool fo r proper asse t val uati o n , ma intena n ce and replacement costing. There is recognition of th e essential role of computerized internal management systems to managing these large assets efficiently and effectively. The seco nd section of the book foc uses on materials engineering from a practical standpoint. A series of different situations are examin ed on a case by case basis. Evaluating the infrastructure of a water trea tment plant (Philadelph ia), un d erta king a plant improvement program , dealin g with pipe failures are among those cited. C hapter 10 provides a toolkit for water main renewal planning with subsequent chapters dealing w ith con dition assess m e nt , pipeline r ep l ace m e nt pla n nin g, and n ew technologies for optimizing m anagement of pipe assets. Section three of the book looks at softwa re for infrastructure management and the range of offerings available to best address individual circumstances. Section four covers issues such as trenchless technology, public involvem ent in asset managem en t program s and

financial modelling infrastructure plans.

111

preparing water

Virus Beha vio11r ill S a tu rated and Unsaturated Subsu,face M edia by Yan

Jin and Marylynn Yates. AWWARF R eport, 2002 ISBN 1-5832 1-202-7 Available booksh op@awa.asn.au. T he US EPA is currently development treatment requirements for public water systems that use groundwater that is not under the direct influence of surface water. It is expected that all public water systems using groundwater will be required to assess their source water for vulnerability to pathogen contamination. T he aim of this project was to estimate the inactivation rates ofpathoge11ic and indicator nucro-organisms in both saturated and unsaturated soils under various environmental conditions. Chapters cover: virus retention and transport in soils under saturated and unsaturated flow conditions, m echanisms of virus removal during transport in unsaturated porous media, effect of iron oxides o n virus transport through porous media, effect of different buffer solutions on virus transport through saturated sand columns. T he final largest chapter details a series of tests of sorpion, inactivation and transport using indicator bacteriophages and human enteric viruses in porous m edia. R ates of inactivation were measured and key mechanisms responsible fo r the inactivation were identified. Diane Wies ner A WA snr scientist


ENVIRONMENT

systems (ri vers that are less flow-im pacted an d hel p us set restorati on targets) . M o nito ring designs fo r enviro n menta l flows still pose c hallenges. R.ep licatio n at appropria te scales (river reach es o r who le ri ver ecosyste ms) is rarely possible and control or reference systems may not ex ist. Also, diffe rent variables and indicators will resp o nd to flow changes in di ffere nt ways and at different temporal scales, e.g. aquatic plants in we tlands may respond w ithin month s w he reas breed ing success of waterbirds may take yea rs to show a resp onse .

Conclusions Freshwa ter scientists, particularly ecologists, are playing an increasi ngly important role in setting and e valuating enviro nm e ntal fl ows in rive r syste ms. T h e pri o riti es fo r th eir research in clude: • H ydrologica l analyses li nking flows to inundatio n of key geom orphi c units. • D ete rm in ing ca usa l links betwee n fl ow eve nts or regimes and ecological responses, o ft e n medi ated via habitat, using flow m a nipulatio n experim e nts.

• E valuating t he relati ve impo rtance of flow compared to oth er hu man activi ties (stressors) that might also degrade ri verine ecosystems (e.g. land cleara nce, grazing, pollutio n). • Designing efficient monitori ng programs to detect eco logical effec ts of e nviro nmental flows and water allocations. These priorities should be an impo rtant component of the research agenda for fres hwater ecology in the comin g decade .

The Authors Bo th are me mbe rs o f the Coope rative R.. esearch Cen tre for Fresh water Ecology. Associate Professor Gerry Quinn is at the School of Biological Sciences, M onash Uni versity : ge rry. q uinn @sc i. m o na sh . edu.au and Associate Professor Martin Thoms is at t he School o f Scie nce an d Des ign, U n i ve rs it y o f C an be rra: thom s@science .ca n be rra.ed u. au

References Arthington A H and Z alucki J M (1998) (eds) Co111pnmti11c /.;11n/11ntio11 of E1111iro11111e111nl F/0111 Assess111m1 Ted111iq11es: Re11ie111 of J\lethods.

L WRRDC Occasional Paper 27 /98, L WRRDC, Canberra. Boulton A J and Brock M A (1999) A11stmlin11 Freshwater Ecolo,~y. Processes a11d .\ /a11age111c111. G leneagles Publishing, Adelaide. Cottingham P, T homs M .and Quinn GP (2002) Scientific panels and their use in environmental flow assessment in Australia. A11s1mlia11 Jmm,a/ ,if IVater Resources 5: I 03-111. DownesB.J, Barmuta L, Fairweather P G, Faith D P, Keough M . Lake PS, Mapstone B D and Quinn G P (2002) .\lo11itori11,~ Ern/ogiml /111paas: Cm,cept.< a11d Praaice i11 F/0111i11g I Vaters. Cambridge University Press. Hobbs R J.and Norton D A (1996) Towards a conceptual framework for restoration ecology. Res1oratio11 Ecoltwy 4: 93-1 I 0. H umphries P. King A J and Koehnj D (1999) . Fish . flows and floodplains: Links between Murray-Darling freshwater fish and their environment. E1111iro11111e111al Biolti~l' of fishes 56 : 129-151. Quinn G P, Thoms M, Butcher R . and Gawnc l3 (2002) (in press) Ecological mon itoring frameworks for flow- impacted ecosystems. Proceedi ngs of t he Internaciona l Work ing Conference on Environmental Flows for River Systems. Cape Town, March 2002. Sherman B (2000) Sropi11s Op1io11s.fc>r Miri,~ati11.~ Cold Water Disdw~~es .from Dams. CS IRO Consultancy R eport 00/21 .

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CALIBRATION OF THE BIOWIN MODEL FOR N-REMOVAL: PART 1, DESKTOP STUDY D W de Haas, M C Wentzel Abstract This project exam ines the effect of certa in key parameters on denitrification predictions of the B ioWi nÂŽ model, compared to the older UCT kinetic model and steady-state theory for activated sludge systems. It shows that earlier versions of Bio Win (distributed in the period ca. 1994 to 2000 and wid ely used in Australia) had ina ppropriate default settings fo r certain key paran1eters that influence the denitrification rate. As a result, the denitrifica ti on rates predicted using th e old er versions ofB ioWin were about three times higher than the so-called K 2 ra te me asured fro m benc h-scale research fo r nitrogen-removal activated sludge system s in the UCT laboratory. Designs based on the higher denitrification rates would likely have under-sized anoxic zones and/ or over-sized internal recycles, leading to higher actual effluent nitrate and total N conce ntratio ns compared to model predictions. This could have ve1y significant contractual and cost impl icatio ns for the upgrade and operation of wastewater treatment plants. The most recentl y released BioWin

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version has revised default settings, which bring it closer to the older U CT family of models in respect of denitrification rate. In this paper we present the results of a desktop study, based on a hypothetical N-removal activated sludge plant as a test case. In Part 2 (to be published in the November issue of Water), we w ill present actual data from a very similar fu!Jscale plant in Australia that was used to calibrate the denitrification rate applied in BioWin. Keywords: Act ivated sludge, mod el, BioWin , UCT , nitro ge n re m ova l , den itrification Introduction Computer-based programs for simulation of activated sludge systems have become w idely adopted in wastewater engineering over the past decade. T hese simulation programs evolved initia!Jy as research tools but are increasingly used fo r design and optimisation of sewage treatment plants. One such program that has become widely used in Australia is BioWinÂŽ. BioWin is available commercia!Jy from Envirosim & Associates (Canada) and

originated mainly from an amalgamation of kinetic models fo r activated sludge systems developed by the University of Cape Town (UCT) and the International Water Association (IWA, formerly IAWQ) (Dold et al., 1980; Henze et al., 1987; Wentzel et al., 1990; Dold et al., 1991; Henze et al., 1995; Barker and Dold, 1997) . Today, the BioWin simulation package has been considerably expanded to include components for unit processes oth er than activated sludge (e.g. grit removal; primary sedimentation; solids separation; and anaerobic digestion). T his enhances model power but also adds complexity. The power of simulation packages in predicting the behaviour of wastewater treatment systems becomes obvious w hen considering the large range of possible process configurat ions. This is especially true when the dynamic behaviour of such systems under variable operating conditions needs to be predicted (e.g. diurnal variation of influent flow). However, the drawback of kinetic mod els for such systems is that they contain a large number of parameters.

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T aking only the m odel components fo r simulating nutrient re moval activated sludge system s, Bio Win uses approx imately twenty-five processes w ith some six ty stoichiom etric and kinetic constants. Fo rcunacely, n o c aJJ of these requi re calibration by the user. However, to use the model appro priately, it is impo rtant chat the user has a good understanding of the m ea ning of chese processes and co n stants. Furthermo re, so me of the constants do require calibration for a given application. This paper fo cuses on appropriate calibrati on of Bio Win for a typi ca l nitrogen (N ) removal acti vated sludge process. Our aim is show po tential picfaJls asso ciated with accepting some of the default parameter settings in che model that have been adopted in che past. In chis paper we present the res ults of a desktop study, based 0 11 a hypo thetical N - removal activated sludge plant as a test case. In th e next paper (Pare 2) , we wi ll present actual data fro m a very similar full-scale plane in Au strali a chat was used co ca librate the denitrifica ci on rate appli ed in Bi0Wi11. Model basics - COD fractions Most kineti c activated slu dge models are based upo n breaking up th e influ ent ch e mica l o;,rygen dem and (CO D) in to four fractions, based on two definiti ons, namely, solubility and b iodegradati o n characte ri sti cs (Figure I): • So lubl e frac tions co nsist o f sm all m o lec ul es th at can pass through a membrane filter (nomin all y 0.45 ~Lm po re size) . Th e unbiod egradable so lub le frac tio n passes through the treatm ent process un changed and ex its with th e efflu ent. Th e b io degrada bl e soluble frac tion is considered to be th e " readily bi o d egradable" frac tio n (RB CO D) and used by hetero trophic o rga nisms fo r gro wth. • Parti culate fractions becom e trapped in th e ac ti v at ed s lud ge fl oe . Th e unbiod egrad abl e parti culate fraction simply accumulates in th e sludge matri x fo r che duratio n o f che solids retenti on time in th e pro cess (th e "sludge age") . The bi odegradable particulate fractio n is co n s id e r e d t o b e th e "s l ow l y bio d egradable" fraction (SBC OD) and consists of large mo lecules (includi ng colloids) that become enm esh ed in o r adsorbed to the sludge floes. En zym es at the acti ve sites of heterotrophic organisms hydrolyse the SBC OD m·oJecules and the hydrolysis produ cts are used fo r growth. Th e Bi o Win mod e l (ori g in all y desc ribed by Barker and D old, 1997) fo ll o ws the IAWQ model approac h (H en ze et al. , 1987 ; 1995) in certain

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respects and the U CT model approach in ocher respects (Dold et al. , 199 1; W entzel and Ekama, 1992) . In respec t ofSB COD utilisation , Bio Win follo ws the IAWQ approach. There is a key difference between the IAWQ and U CT approaches with respect to the manner in which utilisati on of the SBC OD fractio n is modelled (D old and Marais, 1986): • Th e U C T approa ch h as g ro w th processes fo r SBC OD that are separate fro m those for RB C OD. H ydrolysis and growth o n SB C OD are e ffec tivel y modelJed as one co mbined process. The kine ti cs fo r gro wth processes using SBC OD are signifi cantly different and slower than chose for RB C OD. • In the IAWQ approach , all SBC O D is hydrolysed to R.BC OD and conceptually " released " fro m the active sites to join a " pool" o f RBCO D originating partly

fro m the influe nt. All growth ca kes place using the RB COD " pool" as substrate . By means of approp1iate calibration, the UCT and IA W Q approaches ca n be made to give ve ry simi lar predi ctions. SBCO D hydrolysis in the IAW Q approach is m odell ed in an analogous manner to the growth processes on SBC O D in the UCT approach. T he important point is that the hydrolysis o f SBCO D is a signi fica ntly slower process than growth on RB COD. Therefore, once RBCOD o riginating from the infl uent is depleted (o r absent), in the IAWQ approach it is really the hydrolysis rate ofSBCOD that governs the heterotro ph ic growth rate. In co ntrast in the UC T approach, since there is no separate hydro lysis process, hecerocrophic growth is gove rned by the rate of the growth process using SBCOD as substrate " directly". WATER SEPTEMBER 2002

63


WASTEWATER

Table 1. Default settings for key parameters influencing denitrification in different vers ions of BioWin and an older UCT model (UCTOLD). Model

Bio Win ( old) version 4.2 - 4.4

BioWin32 version 1.1.0-1.1.1

BioWin32 version 1 .2.1 +

UCTOLD Dold et al. (1991)

Year of release

ca. 1997 - 1999

1999 - 2000

2001 +

1990 -1991

Parameter

Symbol & Unit

Heterotrophs max. specific growth rate (on RBCOD)

µH (d·1)

3.2

3.2

3 .2

3.2

Heterotrophs max. specific hydrolysis rat e (on SBCOD)

KH (d·1)

2.81

2.81

2.10

2.03

Neta, Anoxic Growth

11s.GRO(no unit)

0.37

0.37

0.50

1.0

11s. AN0X (no unit)

1.0

1.0

0.22

0 .33*

Heterotrophic Yield , Aerobic

YH, AER (mg biomass COD/mg COD util ised)

0.666

0.666

0.666

0.666

Heterotrophic Yield, Anoxic

YH,ANOX (mg biomass COD/ mg COD utilised)

0.403

0.403

0.54

0 .666**

Neta , Anoxic Hydrolysis

* Symbol '11a in UCTOLD, applied to growth process on SBCOD in UCT approach. This is equivalent to 11 s, AX in BioWin/ IAWQ approach (refer to Dold and Marais, 1986). **

In UCTOLD, anoxic and aerobic yields are not differentiated but implicitly equal (Dold et al. , 1991).

Model basics - Denitrification D en itri fication in activated sludge systems is m odelled as a he terotro phic grow th process under :moxie conditions (i.e . w ith n itrate as termi nal electron acceptor instead of oxygen). In th e model stru c ture (b ot h IA W Q a nd UC T approa ch es) , a factor named " neta" is app li ed to m odi fy (slow d own) th e growth processes u nder anoxic rela tive to aerobic conditio ns. In B ioWin there are two neta facto rs that in principl e can in flu ence denitrificatio n: N eta (Anoxic H ydrolysis) (11s, ANox) applied to the hydrol ys is of SB C OD ; and N eta (A nox ic G ro wth) (1lc 1to) for th e gro w th on RBC O O . Fu rth erm ore, th e yield of heterotro phi c bio mass has been found to b e lo we r unde r an o x ic co nditio ns co mpared to ae robi c condi tions (O rhon et al. , 1996; Sperandio et al., 1999). Therefo re, a combinatio n offactors determines the predicted denitrification race, as summarised in Fig. 1: • Amo unts of RBC OD and SBCOD in th e influent • G rowth race o n RBCO D • Hyd rolysis ra te fo r SBCOD

• N eta factors (11s, ANOX an d llcRo) • H eterotrophic yield (Anoxic) Default values in BioWin T he default values for th e key model parameters in B io W in that influence denitrifi cation have changed signifi ca ntly sin ce ea rly versions in ci rca l 994. Table 1 lists th ese default valu es fo r key param eters since 1997. In order to illustrate the sensiti vity of the accivated_sludge m odel predictio ns in 64

WATER SEPTEMBER 2002

respect of denitrification to key parameters (T abl e 1), simulations of a hypothetical reactor test system we re carri ed out.

configuration with a series o f four anoxi c reactors to simulate a degree of plug-flow (Figure 2).

Model simulations for hypothetical N removal system

T h e infl uent sewage ch arac teristics adopted are li sted in T able 2. It was assumed that th e in flu ent hypoth etically contain ed zero RBC OD. T he reason fo r this was that the fast denitrification rate using R.B COO (i. e. the so-called K 1 rate) needed to b e exclud ed in ord er to distingu ish the effect o f mo del param eters relating to SBCO D hyd ro lysis (e.g. neta factors) o n denitrificati o n (i.e. at th e socalled K2 rate). It was further assum ed that th e influ ent TKN was high (relati ve to th e C OD) to ensure that the ni trate co ncentratio n in at least th e first three anoxic

A hyp o thetical test reactor system was set- up using bo th t he BioW in and U C TOLD (D o ld et al., 199 1) models. Bio W in versi on 1.1.0 was used fo r these simu lations since it was in use in Australia in 1999-2000 w h en this study was initi ated. The model structure in Bio Wi n vl.1 .0 conformed closely to that published by Barker and Do ld (1997) as well as that in earlier versions (e.g. v4.2 to 4.4). The test reactor syste m was a simple anoxica ero b ic Modifi e d L udza c k- Ettin ge r

Table 2. Adopted sewage characteristics for hypothetical MLE test system Paramete r

Unit

Value

COD

mg/L

500

BOD*

mg/ L

235

Total SS*

mg/L

272

Inert SS

mg/ L

20

TKN

mg/Las N

90.0

TP

mg/ Las P

10.0

Nitrate

mg/L as N

0.0

Fraction of Sol. Unbiod. COD relative to Total COD

fus

0.05

Fraction of Part. Unbiod. COD relative to Total COD

fup

0.13

Fraction of Sol. Biod. COD relative to Total COD

fbs

0.00

Fraction of TKN as ammonia

fna

0. 75

fnuts) µA, d·l

0.03

Fract ion of TKN as Sol. Unbiod. TKN Max. s pecific growth rate of autotrophs

*

0.50

BOD and TSS from BioWin model estimates

Sol. = Soluble; Part. = Particulate; Unbiod. = Unbiodegradable; Biod.= Biodegradable


WASTEWATER

reactors rem ained high (;;;,:s mgN/L), so as not to influence the den itrification rate.

Raw

Predicted reactor denitrification rates Fig ure 3 presents t he resu lts for th e reactor denitrification rates in the middle anox ic reactor (AX3) . Fig. 3 shows that th ere is a large d ifference in reactor denitrifica ti on rates between the UCT OLD m odel and between diffe re nt ca li brati ons of 13io W in listed in T able 3 . The denitrification rates were more than t h ree ti mes h igh er in th e d efa ult ca lib ration o f BioW in v I. 1.0 (BioWin Case A in Fig. 3) compa red to the defau lt U C T O LD m odel. T he anoxic heterotrophic yield has a la rge effect on the denitrifica ti on ra te. Fo r exa mple, a compariso n of Cases A and 13 in Fig. 3 shows t hat by increasing Y 11 _ ANOX in Bio W in to th e sa me defa ul t value as U CTO LD (0.666), the denitri ficati on rate was reduced by about 35%. H owever, the rate was still approx im ately double that in t he UCTO LD model. The reason for th is is the disparity in neta facto r settings be t wee n th e m ode ls. Comparing 13io W in Cases Ba nd C, it is evident that with ll cRO set to 0.3 7 and 11s. ANOX se t to 1.0 (Tab le 1), the effect o n denit rificario n rate is negligible, co m pared to the case w here both t hese ne ta valu es set to 1.0 (F ig . 3). This is cl ue to the relative ly high rate of growth o n R.BCO D , deri ved in t his case o nl y fro m hydrolys is of SBC O D . It is conceptua lly incorrect to pu t the reduction o nto lls. G llO since it leads to an accum ulatio n or ll BCO D , as is evident for Bio W in Cases A and 13 in Fig. 3 . An accumu lation of ll BCOD in :moxie reactors of N re m oval pla nts is not normally observed (e.g. van H aandel er al., 1982). Instead, the red uction sho uld be pl aced on lls. ANOX (D old and Marais, l 986).

AE1

Q

A recycle (30)

S recycle (1Q)

Sludge age= 20 d; Temp.= 20 °C AX = Anoxic: AE = Aerobic

Figure 2 . Hypothetical MLE test system. 10.0 . . . - - - - - - - - - - - - - 9.0 ,,__ _ _ _ _ _ _ - - - ~ - - \ - - - -

BioWin Case A Default * BioWin BioWin BioWin BioWin

Case B Case C Case D

0.403 0.66 6 0.666 0.666

+- AX 3 reac tor RBCOD

7.0 ,,__ _ _ __

6.0 ,,__ _ _ __

5 .0 4 .0 + - - - - - -1,

3.0 2.0

1.0 Oef aull UCTOLD Default BIOWIN, BIOWIN, Case B BIOW IN Caso C BIOW IN Caso D BIOWIN Case E Case A

Figure 3. Comparison of denitrification rate and anoxic reactor RBCOD predictions for different model cases of the hypothetical MLE system . Refer to Table 3 for definition of BioWin Test Cases. As expected, parity in denitrification ratcs bctwee n t he m ode ls co ul <l be achieved by setting ¡11s. ANOX = 0.33 and 17GRO to 1.0 in BioWin (Case E in Fig. 3) . Alte rnative ly, ifa lowe r va lu e fo r Y 11. ANOX = 0.5-+ is adopted (Spe rand io ei al.,

1999) then parity in rates between the two models is ach ieved using 11s. ANOX = 0.25 and llcm..o = 1.0 in Bio Win (Case 0). T his corresponds closely to the defau lt setti ngs adopted in the latest Bio W in version (v 1.2. I).

Reactor denitrification rate (mgN/ L.h)

Hete rotrophic active mass concentration mg/ L VASS

Specific denitrification rate mgN/ gVASS.d

0.37 0 .37 1.0

8 .119 5.236 5.732

445 6 38 757

0 .439 0 .197

2.387

634

0 .182 0.091

2.445 2. 500

588 642

0 .100 0 .094

2.704

643

0.101

TJS,ANOX

TJG RO

1.0 1.0 1.0 0 .33

0 .54

0 .25

1 .0 1.0

UCTOLD

0.666

0.33

1.0

UCT Steady-state theory**

0 .666

Case E

* BioWin versio n 1.1.0 ** WRC, 1984

c:::::J AX 3 reac tor ON rate

8.0 - t - - - - - -

Table 3 . Calculated specific denitrification rates from BioWin model predictions for hypothetical MLE test system. Model Case

AE2

Specific denitrification rates In order to compare the modelled reactor clenitrificarion rates to published data based on resea rch work, the specific den irri fication (1< 2) rates can be calculated from the model output. The specific rates are expressed per unit active hererotroph ic mass (vo l a t ile active suspended solids, VASS). It is important co take in to account the relative change in model VASS predictions clue to the effect of changing the yield constan t (Y H. ANox) -

WATER SEPTEMBER 2002

65


WASTEWATER

Table 3 summarises the denitrification data for the hypothetical test system cases presented in Figs. 3 and 4. From Table 3 it is evident that a significant difference (ca. 30%) in VASS predictions occurs due to the change in Y H , ANOX when comparing Case A (Bio Win default) with BioWin Cases C or E or with UCTOLD. The greater the extent of N removal (denitrification) , the greater this difference will be. The relative change in VASS is small (<10%) when co mparing cases other than Case A (BioWin default). Therefore the impact of changes in VASS on the specific denitrification rate is comparatively sm all for calibrations other than the default BioWin calibration (v 1.1.0). Table 3 confirms that the UCTOLD calibration (and B io Win after recalibration - Case D) matches the "standard" K2 specific denitrifica tion rate for N removal system s derived from laboratory research data (Stern and Marais, 1974; van H aandel et al., 1981, 1982) and used in steady-state theory (WRC, 1984). Predicted nitrate profiles T he predicted nitrate concentration profile is shown in Figure 4. It should be noted that the efflu ent nitrate concentration would be closely similar to that in the second aerobic reactor, assuming the reactions in the clarifier are negligible. Figure 4 shows the large effect of different model calibrations on reactor nitrate concentrations. T he differences are somewhat exaggerated for the hypothetical test case exam ined, due to the high influ e n t TKN co n ce ntra tions. N evertheless, these results indicate the large potential error that could be made in predicted reactor (and effluent) nitrate by using inappropriate model parameters, such as in the older versions of Bio Win (Table 1). Worse, if th ese m odel paramete rs have been used for design and optimisation offull-scale nu trient removal plan ts, the im plicit denitrifi cation rates wou ld be unrea listically high and the anoxic reactors therefore probably undersized. Similarly, excessive a-recycle rates may be adopted in the design. T he overall implication for the fu ll-scale plant wo uld be sub-optimal nutrient removal performance and power wastage. In Part 2 of th is seri es of paper we will show that denitrification rates observed on a full-scale MLE plant in Australia were very similar to those that form the basis for calibration of the UCTOLD m odel and recalibration of BioWin this study. Conclusions The results of this study have indicated th at :

66

WATER SEPTEMBER 2002

60.0 50.0 ,---

z.,

..

..J

40.0

a, E

i

I.,

30.0

--

--

20.0

-

10 .0

-

a:

-

-

--

-

-

-

- -

-

-

-

-

-

.._

-

-

-

-

O AX5 reactor O AE2 reactor

~

0.0 Default UCTOLD

Default BIOW IN, Case A

BIOWIN, Case B

BIOWIN Case C

BIOWIN Case D

BIOWIN Case E

Figure 4. Comparison of reactor nitrate profiles for different model cases of the hypothetical MLE system. Refer to Table 3 for definition of BioWin Test Cases.

• Kinetic models of activated sludge systems (e .g. including BioWin and the UCT family of models) have the disadvantage of containing a large number of parameters, only som e of wh ich can be measured directly. This can lead to difficulties in model calibration. • Previous versions of Bio Win (versio ns 1.1. 1 or earlier) con tained inappropriate default settings fo r certain parameters, particularly in respect of neta factors that regulate the growth rate of heterotrop hs under anoxic conditions, and hence the denitrifica tion rate. The defau lt settings in older versions of Bio Win lead to hi gh implicit denitrifi cation rates and hence to predictions of lower efflu ent nitrate or relatively small anoxic reactor and/ or high internal recycle requ irements in a typical process configuration fo r N rem oval. • A m ore recent version of Bio Win (v. 1.2.1 or higher) has revised d efault settings for several parameters, which bring it closer to the o riginal UCT m odel kinetic model (U C TOLD) in terms of denitrification rates. T his cam e about partly as a result of th e findings o f this in vestigation and collaboration with the suppliers of the Bio Win model (Envirosim & Associates, C anada). Acknowledgements The fi nancial support of GHD Pty Ltd (Australia) that contributed to this swdy is gratefull y acknowledged . References Barker P S and Dold P L (1997) General model for biological nutrient removal activatedsludge systems: model presencacion. vVnte,E11v. Res. 69 (5), 969-984. Dold P L, Wentzel M C, Billing A E. , Ekama GA and M arais GvR (1991) Acrivnted sludge system si111ulatio11 progrnms (v. 1.0). Water R esearch Conunissio n, Pretoria, South Africa. Dold PL, Ekama GA and Marais GvR ( 1980) A general model fo r the activated sludge process. Prog. Wn t. Tech., 12, 47-77 .

Dold P Land Marais GvR (1986) Evaluation of the general activated sludge m odel proposed by the IA WPRC task g roup . Wnter Sci. Tec/11101. 18, 63-89. H enze M, Grady C P LJ r, Gujer W, Marais GvR and Matsuo T (1987) Activated Sludge 1\llodel No. /. IA WPRC Scientific and T echnical Reports N o . l. IA WPRC, l Queen Anne's Gate, London. H enze M , G ujer W , Mino T, Matsuo T , W entzel M C and Marais G vR (1 995) Activated Sludge Model No. 2. IA WQ Task Group on Mathem atical M odellin g for D esign and O peration of Biological Nutriem Wastewa t e r Trea tm e nt Pr ocesses. lnccrnacional Association o n Water Quality, I Queen Anne's Gate, London. Seem L B and Marais GvR. ( 1974) Sewage as the electron donor in bio logical denicrificacion. Research R eport No. W 7, Dept. of C ivil Engineering, Uni versity of Cape Town, South Africa. Van Haandel A C, Ekama G A and Marais GvR ( 198 1) The activated sludge process . Part 3 - Single sludge denicrificacion. Water Res. 15 , 11 35- 1152. Van Haandel AC, Ekama GA and M arais G vR ( 1982) Optimization of nitrogen removal in the single sludge activated sludge process. Wnter Sci. Tec/1110/. 14, -H3-461 . Wentzel M C, Ekama G A and Marais GvR. (1992) Processes and modelling of nittificacion denicrificacion bio logical excess phosphorus removal systems - a review. Hinter Sci. Tec/11101. 25 (6), 59-82. Wentzel M C, Ekama G A, D old P Land Marais GvR. ( 1990) Biological excess phosphorus removal - Steady state process design. Water SA 16 (1), 29 -48. WRC. ( 1984) T heory, design and operation of nutrient removal activate d sludge processes. Water R esearch Commissio n, PO Box 824, Pretoria, South Africa.

The Authors Dr David de Ha as is w ith GH D (Brisbane office), e-mail address ddehaas@ ghd.com.au. Prof. Mark Wentzel is with the D ept. of Civil Engineering, University of C ape Town (UCT), South Africa.

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Water Journal September 2002  

Water Journal September 2002