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AWA AUSTRALIAN WATER ASSOCIATION ABN 78 096 035 773

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HAMMER is based on technology originally created by Environmental Hydraulics Group, Inc. www.ehg-inc,com

~ 2004 Bentley Systems, Incorporated. HAMMER, WaterCAD, and WaterGEMS are either registered or unregistered trademarks of Bentley Systems, Incorporated or one of Its direct or lndlrecf wholly owned subsidiaries. Other brands and product names are trademarks of their respective owners.


Volume 31 No 8 December 2004 Jo urna l of the A ustra lian Water Association

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

OPINION 2

ASSOCIATION ACTIVITIES 6

Submissions

Strategies for the Future; Education Holds the Key; My Point of View, G Coll ier

Upgrading the AWA Member Database and Website; Australian Hydrographers Association: Looking Forward, Looking Back; IWA Australia Report; National Golf Day

l nmuctions for auchors can be found on page 2 of this journal. Submissions accepted at: www.awa.asn.au/publications/

for WaterAid Australia; Update from the Water Education Network

Managing Editor

PROFESSIONAL DEVELOPMENT

Peter Stirling

12

Technical Editor

CROSSCURRENT

E A {Bob) Swinton 23 Blaxland Road Wentworth Falls, NSW 2782 Email: bswinron@bigpond.ner.au

16

Details of courses, classes and other upcoming water events Industry news

CONFERENCE REPORTS

News Editor Clare Porter Communications Manager Tel +61 2 94 13 1288 Fax: (02) 94 13 1047 Email: cporrer@awa.asn.au

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

22

Modelling of Lagoon Processes - State of the Art, A G ibson

25

Water Efficiency, Bob (EA) Swinro n

FEATURE: SIMULATION & MODELLING 28

MODELLING OF PARTICLES IN WATER SUPPLY SYSTEMS Tracking the transport of particles in water distribution systems A J ayaram e, G Ryan,C Grainger, J Wu, M N Noui-Mehidi

Water Works 35

ARTICLES CONTRIBUTED BY THE WATER OPERATORS INDUSTRY ASSOCIATION

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NationaJ SaJes Manager: Brian Rault Tel (03) 9530 8900 Fax (03) 9530 891 I Mobile 04 l l 354 050 Email: brault@halledit.com.au

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Water (ISSN 0310 - 0367)

ARTIFICIAL NEURAL NETWORKS: A FLEXIBLE APPROACH TO MODELLING ANNs perform in a variety of roles in the water industry. H R Maier, G C Dandy

61

HOUSE WATER EXPERT: WATER MANAGEMENT SOFTWARE FOR HOUSEHOLDS An educational tool with further potential. A Grant, VG M itchell and E Dell 'Oro

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PO Box 388, Arrarmon, NSW 1570 Tel +61294 13 1288 Fax: (02) 9413 1047 Email: info@awa.as n.au ABN 78 096 035 773

Some dear trends were found across the region M A Burford, K McNea le, C Krogh, M O 'D onohue, T Packer, T McAJister

AWA

President Rod Lehmann

Chief Executive Officer

ifji

68

AUSTRALIAN WATER

COMMUNITY CONSULTATION

ASSOCIATION Chris Davis Australian Water Association (AWA) assumes no responsibility for opinions or statements of fucts expressed by contributors or advertisers. Editorials do not necessarily represent official AWA policy. Advertisements are included as an information service to readers and are reviewed before publication tO ensure relevance to the water environment and objectives of AWA. All material in Water is copyright and sho,Jd not be reproduced wholly or in part without written permission.

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COMMUNITY VIEWS ON DRINKING WATER QUALITY IN AUSTRALIA'S CAPITAL CITIES A national survey of customers' perceptions of water quality. N Roseth

72

CONSULT, COLLABORATE OR EMPOWER? First clarify what you want to achieve. L Cole- Edelstein

PROJECTS 76

KWINANA FREEWAY BUS TRANSITWAY STORMWATER PROJECT A practical application of water-sensitive design. I Hare, K Zic

WATER BUSINESS 81

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OUR COVER: Local government is becoming actively involved in water efficiency measures. The City of Greater Geelong was one offive councils which were finalists in the 2004 save water awards organised by the National Water Campaign run by /CLE/, the International Council for Local Environment Initiatives. Pictured is the City of Greater Geelong's 21st Century Garden in the Geelong Botanic Gardens which uses less than one per cent of the water ofthe original gardens, mainly due to plant selection. For a report on the A WA 's Water Efficiency Conference, turn to page 25.


from the president

STRATEGIES FOR THE FUTURE In the lase two months we have seen some significant developments in the water industry. T he NSW Stare Government released a lo ngawaited Merrowarer Strategy fo r Sydney's water supply. T his strategy detai ls rhe plans fo r development of Sydney's Water supply to meet the estimated water needs fo r the next 25 years; and a notable feature of rhe strategy is char there are no new dams proposed. Ir does incorporate a mix of new sources and upgrading of old sources, including a proposal for deep water pu mping from the lower level of th e Warragamba Dam and, potentially, a large desalination plant. T he strategy has been some rime in coming but it provides a sensible approach to water management, encompassing a wide range of water management options, including demand management and water recycling. Ocher maj or water authori ties are either in the process of developing or have developed water supply strategies, fol lowing long periods of lower than average rainfa ll. Mose are adopting a multiple source type approaches and most inco rporate an element of water recycling. T he use of recycled water still causes some difficulties with rhe community and our very own

considered in isolation. W hen considered as part of a total water management system, rhe costs become more comparable wi th conventional systems. There is also considerable debate in the water industry as to what are the minimum requirements fo r using recycled water for such uses as irrigating golf co urses and sporting fields, fo r example. Some suggest char "tertiary" treatment is requi red, bu r it is rarely provided. As an industry we need to be bringing these issues to the forefront and trying to reach some sensible agreement. We still have a mix of guidelines and standards which vary from state to state; and then there is the National Water Q uality Management Strategy as well. Clearly we have a lot of work to do within our own industry as well as

The strategy has been some time in coming but it provides a sensible approach to water management, encompassing a wide range of water management options, including demand management and water recycling. practitioners, despite many years of proven perfo rmance for a number of sys tems. Dual pipe systems, for example, have been successfully implemented in a number of areas, bur rhe cost of such systems is high if

2 DECEMBER 2004

water

with the commu nity if we are to move forwar d with comprehensive water recycl ing schemes. To th is extent we see it as most impo rtant char we start to educate our industry as well as

the community in all aspects of the water cycle and especially water recycling. As part of ou r education program we can provide a lot of useful information and tools to help practitioners to deal with issues relating to water management and water recycling. We are also setting up a communication network for people interested in water education. If you are interested in that - please contact Corinne Cheeseman at AWA's office in Artarmon. I had the good fortun e to attend the New Water Profess ionals Forum in Brisbane in October. Th is involved a mix of presentations and a workshop session to deal with so me of rhe disparate interests associated wi th finding new sources for supply of water. T he delegates were divided into a number of groups and each asked to review th e problem at hand from their group's perspective. The groups represented, variously: ratepayers; a bowling cl ub; rural irrigators; the water authority ere. Ir was an interesting session and led to some lively discussion within each group. Ir was particularly relevant in view of the current activities in South East Queensland relating to rhe supply of additional water to the Gold Coast. T he invited speakers at the seminar included Dr James

water FUTURE MAJOR FEATURES FEBRUARY - Tre nc hl e ss Technology, Coastal CRC MARCH - Sustai na bil ity, W astewater Treatment, Odou r Control

MAY - CRC Freshwa te r Eco logy , Technology

M e m b ran e

Moody and Professor N ancy Millis. I was particularly interes ted to hear rhe presentation from James Moody; he discussed the change that had occurred in the l nsrirurion of Engineers as a result of the emergence of a strong and enthusiastic group of young professionals, keen to get involved in rhe running of the Insti tution. I believe char there is significant opportuni ty for AWA to reach out to our young members and get them more involved in the runn ing of the Association. O ver the next few months we will begin a dialogue with our younger members about their role in the Association. Any suggestions would be welcome.

Rod Lehmann

water

Contributions Wanted

Water journal welcomes the

submission of papers equivalent ro 3,000-4,000 words (allowing fo r graphics) relating ro all areas of the warer cycle and water business ro be published in the journal. Topical stories of up ro 2,000 words may also be accepted. All submissions of papers intended for the main body of the journal should be emailed ro the Technical Editor, bswinron@bigpond.net.au. Shorter news items should be emailed to news@awa.asn.au. A submitted paper will be tabled at a monthly Journal Committee meeting where, if appropriate, it will be assigned ro referees. T heir comments will be passed back ro the principal author. If accepted and afrer any comments have been dealt wich , che final paper can be emailed with rhe text in MS Word bur with high resolurjon graphics (300 dpi riff, jpg or eps files - Zip disks or CO-ROMs can be accepted) as separate files, or hard copy phoros and graphics sui table fo r scanning by the publisher can be mailed ro 23 Blaxland Rd, Wentworth Falls, NSW 2782.


conferences Canberra compared rewards and penalries.(Their paper will be published in a furure issue of Water). Richard Swinton , Department of Agriculture, NSW, extrapolated hi s philosop hy of getting fa rmers to embrace new culrures and methods to rhe challenge of changing the typical urban customer. T he basis is rhe same. A habit is a comfortable siru ari on. To change a habit in che short term, eg, in an emergency (s uch as a drought) is easy, bu r when rhe stress or need is relaxed, reversion is most li kely, particul arly if any regulation is perceived as a top-down approach. T o ach ieve a permanent change requires rhe new habit robe demonstrated as more co mfortable tha n the original. Education raises awareness, reduces fear of rhe unknown , and can clarify the process of change. Any change must be integrated into the context of rhe whole fa rm system in cludi ng social and perso nal issues. Collabo rarion between all stakehold ers builds synergy and support, an d he has found that 'even' fa rmers are keen to 'do the right thing' and peer pressure is perhaps more effective than regul ation. Regul ation to co ntrol rhe outlaws will be necessary bur wi ll be accepted by the majority as fair. Joe Hurley outlined the educational benefits of the CERES Co mmunity Environment Park in inner Melbourne, where inter al ia, many home-scale water savi ng systems are being demonstrated. Gary Bickford hailed Canberra's success in reducing consumption by 40%, by implementation of Stage 3 resmcnons. None-the-less, Russell Beatty re-iterated research done by MWH (published in Water, June, 2004) that the underlying per capita co nsumption is actually rising, in line with increasing affluence. Andrew Grant of CSIRO introduced rhe House Water Expert software (in this issue)

and Kirk Stinchco mbe of Gold Coast Water presented his research on rhe optimal method of persuad ing people to install low-flow shower heads, identifyi ng rhe key barriers and evenrually reco mmending the home retrofit program. Robert Shaw outl ined the potential fo r savings by simple DIY plumbing, Tony Cartwright of Sydney Water stressed the need to establish minimum sta ndards fo r rhe growi ng proliferation of 'watersaving' devices, referring both ro rhe labellin g scheme and also

to rhe Building Susrainabil iry Index. T his excellent scheme, BASIX, was outl ined by David Eckstein of rhe Department of Infrastructure, NSW. As from July 2004 all plans fo r new housing in NSW must score a minimum nu mber of points, which rake in to account both water and energy efficiency, and Terry Lustig of Aqua Consulti ng reported on case studies of total watercycle manageme nt and applications of the BASIX too l. Final ly, Professo r Peter Coo mbes delivered rhe resul ts

of ten years of research at Newcastle University on bridging the gap. The potential for even relatively small urban rainwater ranks is there, provided they are linked to the reticulated supply and operated properly, nor as reserve storages. In wrapping up the fina l discuss ion, Chris Davis stressed that social strategy is now a large part of an engineer's responsibility, as is evident in the number of papers on this theme which are being publ ished in this Journal.

Has your traditional GIS vendor left you stranded? The traditional GIS vendor's approach to spatial data will only take you so far...

water

DECEMBER 2004 27


MODELLING OF PARTICLES IN WATER SUPPLY SYSTEMS A Jayaratne, G Ryan, C Grainger, J Wu, MN Noui-Mehidi Abstract I n Australian drinki ng water supply systems the largest proportio n of water quality customer complaints are related to d isco loured or 'dirty water'. However, little is known about the origins and movement of the particulate material chat causes such complaints through the water supply system. To address chis gap the Cooperative Research Centre for Water Q uality and T reatment (CRCWQT ) commenced developmen t of a computer sim ulation to model the movement and accu mu lation of particulate material within the water supp ly system, based on laboratory investigation of particle movemen t. Seven water ut il it ies: Syd ney Water, Brisbane Water, Un ited Water Intern ational, Water Corporation, Melbourne Water, South Ease Warer and Yarra Valley Water; and Commonwealth Scientific and Industrial Research Organisatio n (CSIRO) participated in chis research p roject, wh ich was completed in December 2003. One of rhe p roject o utcomes was the development of a si m ple particle model termed the Particle Sediment Model (PSM). The PSM tracks the transport, settling, and re-suspension of particles in warer distribution systems, which should then help warer uriliries in the develop ment of proactive warer main s cleaning programs. T his paper presents rhe rheory and data associated with construction of chis model.

Table 1; Velocity required to suspend non-cohesive, loosely deposited particles in pipes. Particle diameter (mm)

Pipe diameter

0.200 0. 100 0.050 0.020 0.010

Velocity for re-suspension (m/ s) Pipe diameter

=100 mm

0. 220 0.195 0.1 86 0.1 25 0.09

0.2 75 0.25 0.19 0.16 0. 12

Particle SG=2.6, pipe roughness 0. 1mm. account for up to 95 per cent of all dirty water d etections (Thames Water, pers. com. 2002) or as law as 17 per cent (Prince et al., 2000). Similarly, rhe ability to determine rhe origins of rhe particulate material varies between different water supply systems,

Size and Movement The size d istrib ution of suspended particles is a governing factor in their locatio n and movement (Krishnappan 2000). I t is expected chat larger sediment

The Particle Sediment Model tracks the transport, settling, and re-suspension ofparticles in water distribution systems, thus helping proactive cleaning programs. with possible sources being from catchmen t, treatment p rocesses, b io fil m growth within the water su pply p ipes, corrosion p roduces o r ocher unidentified factors.

fract io ns would settle closer to the so urce and char fi ner fractions would be transpo rted over long distances th roughout rhe water supply system because of seed ing

RESUSPENSIONVELOCITIES AFTER 24 HOURS CONSOLIDATION 0.30

0. 28 ~

-

0.26

Background

0.25

One of rhe key performance and com pliance ind icators for water uriliries are water qual ity customer co m plaints about discoloured or 'dirty water'. Such discoloration is frequen rly caused by particulate material fro m th e reticulatio n system ap pearing at rhe customer rap. In Australia, little is understood of rhe origins, transport and face o f such material, yet ir may cause up to 60 per cent of water quality related customer co mplaints to a water auth ority (Prince et al., 2000 ). T he ability to identify events which give rise to dirty water at a customer's tap va1-'ies consid erably depending o n the reticulation system and source water (Walski 1991; Yarra Valley Water 1999; Prince et al., 200 0). I dentifiable causes may be able to

28 DECEMBER 2004

water

=600 mm

0.23 0.22

Cl Higher Value

0.23

~

0.21

0.21

-

~ 0.20

i.,

• Lower Value

0.17

~

0.21

0.21

0.20

-

0.17

a.

-~ 0.15 E 0 0

.!: 0 10

~ -

¡g ~

0.05

0.00

~

Yarra Vallty Water

South Ent Water

United Water lntematlonal

--

Brisban, Water 1

Brisban, Water 2

--

Sydney Water

Figure 1. Velocities req uired to resuspend particles in a 10 0 mm diameter pipe. Particulate materia l w as obta ined from tanks in the water supply system of each w ater utility.


forces due to gravity (Walling and Moorehead 1989) . Studies by Gauthier ( I 997) and Boxall et al. (200 l) highlighted that rhe occurrence of water with a high level of turbidity is significantly more likely when particles were less than 40 to 50 microns in size. Each study was of a different water supply system and water source, ind icating chis finding to be consistent despite the different matrices inherent to each system.

••• •••

• • - --• •

• • • •

Particle Settling The settling rare of particles in a water pipe is primarily governed by flow. Under quiesce nt conditions i.e. no flow, particles secrle due to gravity. T he race of settling is governed by their terminal velocity through water, as determined by particle size and specific gravity (S hook and Roco, 199 1).

• • • •

••

• •

------·

• •

. ..

Laminar flow

L1mi nar flow occurs as rhe warer begins move, befo re the flow is great enough to induce turbulence. In laminar flow, particles settli ng due to gravity are acted on by ocher forces which can potentially maintain suspension, or slow rhe settling velocity, the Saffman and Magnus life forces (Fan and Zhu 1998) . The Saffman force is dependent

Figure 2. Illustration of Ud and Urs.

to

on rhe grad ient of velocity to produce a life fo rce. Typically smaller particles experience a larger Saffma n force. The Saffman force may increase salcacion of particles along che bottom of the pipes.

r more information and a local stockist contact Davey on 1300 367 866

A second force acting upon che particles is rhe Magnus life fo rce, which exists where the particles spin. Particles may spin because of contact with the wall, or because of shear forces in velocity gradients. The


Table 2. A typica l set of gravitationa l model parameters, based on Ya rra Va lley Wate r pa rticle samples for a 100mm d ia me te r pipe. u, (m/ s)

u,. (m/ s),

0.20

1.6 X 10·6

0.07

Magnus lift fo rce primarily affects particles smaller than 10 µm.

Turbulent flow Laminar to turbulent flow transition in a pipe is well researched, and it is generally agreed to occur at Reynolds Numbers (Re=pVD/µ, where Vis the pipe average velocity, D is the pipe diameter, p is the flu id density, ~1 is the dynamic viscosity) over 2000. This corresponds to a flow velocity of approximately 0.02m/s in a lO0mm-diameter pipe. In turbulent flow suspended particles are maintained in suspension against gravitational fall velocity by boundary layer generated turbulence. This requires that the mean vertical turbu lent velocity (v') be equal to or greater than the settling velocity. Based on this theory, particles would settl e out in the laminar flow condition, sin ce v' =0 at zero turbulence, however, there are other fo rces which still act in laminar flow, as described.

Resuspension Resuspension of loosely deposited noncohesive particles has been extensively studied in hydraulics because of its importance to river engineering, refer to Vanoni (1975) for a comprehensive review. Fundamentally, it is the shear stress that controls the fluid dynamics of the resuspension process. The mean shear stress at the wall of a water pipe is a function of velocity and the pipe roughness and diameter, and ca n be found readily if the pressure loss is known. Entrainment of particles from a sediment bed starts when the shear stress at the bed is above a critical value and can be predicted based on work by Shields (1936) and modified recently by Subhasish (1999). Based on the Shields curve, the critical velocities required to suspend particles have been calculated and presented in Table 1 fo r pipe diameters of 100mm and 600 mm. As is expected, the critical velocity to resuspend particles increases with particle diameter. However, it may not be immediately obvious that it also varies with pipe diameter. It is useful to point out that the critical velocity required to re-suspend particles is a lot larger than the velocity required to keep particles in suspension. For example, at a

30 DECEMBER 2004

water

PIPEID 2068 2070 2072 2074 2076 2078 2060 2062 2064 2066 3000

FROM NODE OON4584 DON4624 DON4391 PE5391 PE5364 PE5360 DON3261 PE5390 PE5363 OON4125 M272 160

NODE ID OON4564 OON4624 DON4391 PE5391

TO NODE LENGTH (Ml DIAMETER 96 PE5385 35 87 726 PE5386 1369 96 PE5389 151 DON4966 3616 67 16.93 DON4297 DON3365 14997 387 276 PE5381 55 39.33 96 DON3536 DON3796 26 52 96 151 1016 PE5382 0 225 225 M272 161

TIME (HOURS) 0.0 MATERIAL ROUGHNESS CICL 06 031 CICL 08 -0.36 CICL 006 015 06 -064 CICL CICL 1.01 0.16 0.6 366 CICL CICL 0 .06 0 23 0.3 0.06 CICL 0.3 0 CICL CICL 0.6 062 07 -13 CICL

0.1

0.2

0.32 -0.39 0 .15 -066 0 .19 3.46 0. 23 0 07 0 056 -1345

029 -0. 35 0.14 -0.6 0.17 2.9 02 0.06 0 049 -12 23

ELEVATION(m)

X (m) Y(m) 5819040 50 334172 31 334965 59 5819597 00 5819011 50 336366.50 56.00 5819788 91 335961 .86 92 47 51 27 337013 18 5816230 61 5616695 64 49.71 339626 06 339738 94 5818320 00 48 00 5819338 65 70.70 339528 64 54 20 6602

PE5364 PE5380 DON3281 PE5390 PE5383 DON4125 M272 160

0.00 70 47 66.90

337922.91 339859 63 334964 61

562002616 5620397 00 5819574 00

Figure 3. Example import fi les of data from a hydraulic model prepared fo r the PSM. Preston T ube. T he shear stress was then co nverted to a velocity in a I 00mm pipe. Resuspension of the particles was determined by visual inspection. The lower reading indi cated the velocity at which particles srarted co slough from the surface, che upper representing the point at which all particles entered the bulk flow. Although the particles originated from different source waters the velocity at which particles were resuspended was between 0.17 and 0.27 m/s for all water utilities. T he results are shown in Figure I.

velocity of 0.04m/s (pipe diameter of 100mm), 50µ m particles are kept in persistent suspension once suspended. However, the velocity required to resuspend these particles is approximately 0. l 9m/s, even if particles are loosely deposited. Note also that the critical shear stress co re-suspend particles is relatively insensitive co particle diameter for small particles.

Particles Model Development

Flow tunnel Particles collected from water supply mains were initially analysed in a flow runnel at CSIRO co estimate the shear stresses required for resuspension. Samples were obtained from water mains (flushed from hydrants) from five water utilities across Australia. The particulate material was allowed to settle and consolidate over a 24- hour period before being introduced into the flow runnel. The samples were then introduced into the flow runnel such that the consolidated material was not disturbed. T he flow was gradually increased and the shear stress calculated fro m measurements of pressure taken using a

=

Pipe test loop To confi rm particle movement theory under simulated field co nditions a pipe test loop was established (Figure 2). T he test loop was a 41 m long, 100mm internal diameter pipe of cast iron, co ncrete lined (CICL) into which particles were deposited. The deposited mass was then moved around the pipe cesc loop by a specially designed axial flow pu mp. The axial flow pump was designed co create low swirl and curbulence so chat the particle distribu tion entering it was not grossly changed by che pump. A variable speed

---=

Pa~C:~i~Lli_S_S__·_.Tl•_:,_·_. :_. _: ._,._,._::_:.-.r{- ; -·:_ ..·_:._..._.'_·._. ..,· Pipe

Distribution of particles in suspension (M,cl

~

_ ____.I-

)

Particles mass

out (dM 0 )

Particle sediment mass (Ms)

Figure 4. Illustrative diagram of components used to calculate particle movement in the PSM at each time step.


SPIii to environment

from manhole

Sewer manhole

H,gh 18'1ol alarm ttansmined to

D

~!!~;;ssmt

system before spill

SOUTH EAST

WATER

D

g~

_-!>~


controller and flow meter facilitated operation of the test loop over the range of meas ured water velocities. In order co measure the concentration and sizes of particles in the test loop a sample flow of 100 mL/min was drawn through a particle counter by a peristaltic pump and reinjected into the particle test loop further downstream. T he particle counter was connected to a computer co log counts of particles of specified sizes. Logged data was then used co determine particle size distributions. The pipe test loop was used co determine th ree critical velocities associated with gravitational settling: • The setrli ng velocity of particles in quiescent flow(U,); • The velocity at which particles started co setrle our of solution (Ud); and • The velocity at which all particles were resuspended into solution (Urs)· A typical set of values for these three parameters is listed in Table 2, obtained from testing particle samples from Yarra Valley Water.

Particles Simulation Model (PSM)

Olinda Mitcilom

Ellhom

182.8m

onoromo Av)

120.lm

Donco,ler !:ost Ref. 141.lm

Oiinda Mitchortl i82 .3m

Figure 5. Ya rra Valley Water case study area and filter locations. hydraulic model in six-m inute intervals over a 24-hour period. The user must also enter a particle loading as either a co ncentration or single point input of particle mass. This data can be entered for as many pipes as the user desires, at any location in rhe water supply system. T he import file for hydraulic model data is a flat comma delimi ted text file, and so there is no restriction on the type of rhe hydrauli c modelling software that can be used with the PSM. Examp les of rhe two input data files from rhe hydraulic model H2OMAP for Yarra Valley Water's Doncaster East Zone are shown in Figure 3.

user interface co run rhe PSM code, with the followi ng features: • Graphics co visually present rhe particle mass distribution through the water pipe network with time; • User dialog boxes co interact with individual pipes, enabling "adding" particles, inspecting particle mass data at any location and, setting up parameters for the PSM engine; • Export of the particle mass distribution from rhe model co comma delimited text files.

The information from the pipe test loop was used co form the basis for a particle sediment model (PSM) to predict the movement of particles through water pipes. It was hoped that using the basic principles learnt from the pipe test loop investigations that ir would be possible co develop an accurate simulation of particle depos ition and resuspension in the water supply system. An initial version of rhe PSM was PSM Engine developed using Shield 's criteria, requiring PSM Software PSMSedimentCalculacor.cpp is the the input of particle size and specific gravity program behind the PSM engine. This is Software Window Platform to model particle movement. written in C++ and is rhe main program New Para Engineering Software However, through rhe laboratory containing all the key algorithms fo r developed the PSM as a 'Windows' investigations using the pipe test loop it was calculating transport of the particle mass in platform under a contract from CSIRO as poss ible co simplify these assumptions. the water supply system. the front end for a Windows visual C++ Empirical measurements of the average Particle mass parameters described in engine. The W indow's platfo rm provides settling rate of particles over time Figure 4 are calculated at each time were substituted for individual step for all the pipes: particle size and specific gravity • dM; 11 , particle mass transport into measurements co obtain an rhe pipe, during time step ~,; approximate rate for gravitational • dMo , particle mass transport out removal of particles. T he velocity at of the pipe, during time step ~,; which the particles were resuspended could be averaged • Mx, particle mass per unit length because of rhe small range of distribution along rhe pipe at time,; velocities over which particles were • Ms, particle seeded at time ,; entrained into the water column. T he following are the main steps The velocity at wh ich particles used in the PSM engine: started co setrle from the water 1. The particle mass output dM0 column was noted as slighrly from each pipes at time t are used to turbulent flow. calculate the mass input into the In addition co particle settling current pipe at the next time step velocities, rhe PSM requires rhe t+~t: input of flow data from a calibrated Figure 6. Filter unit used to col lect particulate material.

32 DECEMBER 2004 water


Q L" dM 0 (1 ) dM,,, (t + t::.t) - ~ L, Qk

where Q is che fl ow race in che pipe, Q_;, is che flo w from che kch pipe connected co (and with flow into) the curre nt pipe, and I dM 0 (c) is the coral mass into the current pipe fro m all che pi pes connected co it ac each time seep. A fu nction was developed co identify chose pipes conn ected ac che inlet of any given pipe. 2. Calculate particle mass parameters fo r each pipe, given input mass dM; 11 ., 3. Calculate particle seeding scacus param eter s. 4. Repea t calculations fo r all the pi pes. 5. Calculate che nex t tim e seep fro m (1).

PIPEID

2068 2070 2072 2074 2076 2078 2080 2082 2084 2086 3000

Mass Settled (kg)

0 .000301 0.000006 0.001152 0.004498 0.001794 0.026495 0.000867 0.002531 0.000000 0.000252 0.000000

Mass Suspended (kg)

0.000000 0.000000 0.000001 0.000000 0.000000 0.000146 0.000000 0.000000 0.000000 0.000000 0.000000

Concentration (ppm)

FilterMass (kg)

0 .000443 0 .002295 0 .006290 0.000260 0 .000000 0.008262 0.000001 0.000000 0.000000 0.000000 0.000000

0.000109 0.000107 0.000104 0.000110 0.000085 0.000138 0.000241 0.000290 0.000000 0.000083 0.000098

Case Studies for Model Tes ting

Figure 7. A n example output file from the PSM ind icati ng the mass of particulate material in each pipe, along with the mass of material in the water colum n, the concentration and the predicted mass of materia l that would be deposited o n a calibration filter unit attached to that particular pipe.

A case study was undertaken at Yarra Vall ey Water's, Don caster Ease water supply zo ne (Figure 5) co validate rhe PSM. T hi s zo ne was selected due to its simplicity, single so urce of supply from che Doncaster rank, domestic custo mer base, ava ilability of a cali bra ted hydrau lic model and a history of higher than average d iscoloured water comp lai nts. Water mains in the zo ne and the ra nk were

cleaned prior co the commencement of the case scudy. Specially designed filter uni rs (Figure 6) were installed at th e outier of rhe Doncaster rank and at 20 customer properties across rhe zone co measure rhe sed iment mass leaving the water supply system at these pro perties. The size of the filter, fi lter flow and rhe duration of the cesc were

determ ined based on 11 u 111 ber of trials carried ouc at che CSIRO. T he best co mbi na tion of these variables co max im ise the capture of sediments were: • one micron fi lter; • 0.02li rres/s of continuous flow through the filter; and • continuous operation fo r 10 days.

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water

DECEMBER 2004 33


The weight of the dry filters was measured before and after the 10 day trial period to compute the sediment mass and the concentration at each site. The measurements were then repeated each month fo r a period of 12 months. T he simulated filter fl ow in the PSM was set at the test flow rate of 0.02licres/s to compare the measured and predicted sediment masses. The input flows for che PSM fro m the hydraulic model were computed for each day of cbe 10 day cesc period by adjusting the demand profiles based on online flow measurements taken in ch e zone. A typ ical output from che PSM is shown in Figure 7. The comparison of model results wirh measured sediment mass indicate that there is up to a 50 per cent d ifference berween the rwo results (Figure 8). There is greater correlation between the two results closer co the water source with degree of association decreasing with distance into the system. T his result is consistent with the accuracy of the hydraul ic model, which had a greater number of calibration points closer to rhe source, wirh less cali bration furthe r into rhe system. It also reflects rhe variability of flows in smaller diameter pipes with fewe r customers, with rhe flow in each pipe mo re affected by who turns on a tap, and at what rime. W hereas rhe larger pipes, closer to rhe so urce have a more aggregated fl ow, which is better able to be represented by the hydraulic model. The modelling o f sediments is also complicated by uncontrolled system operational changes, burst mains etc, which can randomly trigger movement o f particles.

Conclusions The PSM is currently a basic sediment movement model able to predict gravitational settling and fl ow induced resuspension of particulate material in the water supply system. T he accuracy of this pred iction is related to the accu racy of the available hydraulic model. T he ability of che model to reliably pred ict region s of sediment accumulation within the water supply network is being confirm ed th rough case scudies being undertaken at four water urili cies across Austral ia. T h ese studies are likely to in volve mains clea ning to evaluate che amount of accumulated sediment and confirm wheth er the model is able to p redict absolu te and relative amounts of material accum ul ated . This work will b e used to determine if further work is necessary to inclu de sim ulation of other variables such as adh esion of particles to

34 DECEMBER 2004 water

PSM and Filter Results (30/10/02 - 7/11/02) 0.0 12 ~ - - - - - - - - - - - --

- -- - - - - - - - - - -~

-+- Measured

..... PSM Prediction

0.010

_

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., :E c

0.006

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3

4

8

9

10

11

12

13

14

15

16

17

18

19

20

Filter location sorted from source to furthest property

Figure 8. An example of the measured sediment masses on filters and the outputs of the PSM for one 10 day analysis period in the Doncaster East water quality zone of Yarra Valley Water. the p ipe wall through chem ical and biological mechanisms to more accurately pred ict sites of particle accumulation. If a predictive correlation can be developed between rhe sediment accumulation rare and the PSM sediment accum ulation values, rhen ir should be possible to use rhe PSM to develop optimal mains cleaning programs. It is anticipated char the case studies wi ll be complete by the end of 2005, and if successfu l char the PSM would be made available to all water utilities through che CRC for Water Quality and Treatment.

Acknowledgements The authors wish to acknowledge che valuable contributions made to this project by rhe staff of the parti cipating water utilities in particular Bon Nguyen from CSIRO Division of Manufacturing and Infrastruccure T echnology, C live Copelin at Sydney Water, Francis Pamminger at Yarra Valley Water and Mark Beaton from Abigroup (Yarra Valley Water's maintenance contractor). This project was funded by the Co-operative Research Centre for Water Quality and Treatment

The Authors Asoka Jayaratne and Greg Ryan are rhe co-project leaders for this CRCWQT project. Greg is rhe Manager Water and Effluent Plann ing at South East Water and Asoka is a Water Quality Planning Engineer at Yarra Valley Water. Jie Wu is rhe Team Leader at rhe CSIRO Division of Manufacruring and Infrastructure Technology, Clive Grainger is a Senior Research Scientist and Mohamed N NouiMehidi a Research Scientist at the CSIRO.

References Boxall, J.B., Skipworth, P. J. and Saul, A. J. (2001 ) A Novel Approach to Modelling

Sediment Movement in Distribution Mains Based on Particle Characteristics. University of Sheffield , UK. Fan, L. S. and Zhu, C. (I 998) Principles of Gassolid Flows, Cambridge University Press. Gauthier V., Portal J.M., Rosin C., Block J.C. , Cavard J . and Gatel D. (1997) How good are water distribution systems for t ransport of particulate matter, Proceedings of Wac. Q ual. Technol. Conf., Am Wat Wks Ass, Denver, 18pages. Krishnappan, B.G. (2000) In-situ size distribution of suspended particles in the Fraser River./. Hydraul. Eng. 126(8): 561-569. Prince R., McManus, K, AM, Coulter, [. (2000) Colour, Turbidity Levels and Dirty Water Cusromer Complaints - Water System Performance l ndicacors? World Water Congress, 12-17 Mar, Melbourne, Australia. Shields, A. (1936) Application of similarity principles and turbulence co bed-load movement, Mitteilunger der PrettSsischen

Versuchsanstalt fi;r Wasserbau und Schiffbau, 26, 5-24 . Shook, C.A. and Roco,M.C. (1991) Slurry Flow: Principles and Practice, BuccerworthHeimeman n. Subhasish Dey, ( 1999) Sediment Threshold, Applied Mathematic Modelling 23 399- 417. Vanoni, V. A. ( 1975) "River dynamics." Advances in applied mechanics, Vol. 15, Academic, San Diego, 1-87. Yarra Valley Water (1999) "Dirty water Complaints in Courts and Dead End Streets". Yarra Valley Water Discussion Paper. [unpublished draft]. Melbourne, Aust ralia, pp 17. Walling D.E. and Moorehead P.W. (1989) The particle size characteristics of fluvial suspended sed iment: An overview. Hydrobiologia, 176/177, pp. 125-149. Walski T. (1991) Understanding solids transport

in water distribution systems, AWWARF, Cincinnati, OH, p 305-309.


ARTIFICIAL NEURAL NETWORKS: A FLEXIBLE APPROACH TO MODELLING H R Maier, G C Dandy Abstract Artificial neural networks (ANNs) are a co mpuracional cool based on an analogy co che structure and operation of rhe human brain. T hey provide a flexible way of approximati ng highly non-linear relationships between variables wirhouc the need co make a priori assumpti ons about the form of rhe relationships. ANN models have been used fo r prediction and forecasting in a large number of areas of hydrology and water resources. In th is paper, a number of case studies are presented co demonstrate the successful application of ANNs in the water industry. These case srndies incl ude fo recastin g salinity in che River Murray 14 days in advance, fo recasting Anabaena spp in che River Murray 4 weeks in advance, predicting the alum dose required co achieve pre-determined water quality levels at a water treatment plant and fo recasting chlorine levels near che downstream end of che Myponga trunk mai n 24 hours in advance. The case srndies demonstrate chat ANNs perform extremely well in a variety of modell ing and fo recasting roles.

Introduction Artificial neural networks (ANNs) are a computational cool based on an analogy co the strucrn re and operation of che human brain. The brain processes in fo rmation using billions of interco nnected process ing elements called neuro ns. Al though che processing ab ility of each neuro n is li mited

1

/ .•···•······•...

Input

~-~ ··:>

Output

Figure 1. Typical structure and operation of a multi-layer perceptron, the most commo n type of artific ia l neural network.

Artificial neural networks mimic che scrucrnre of the neural networks fo und in the brain in char they consist of a number of processing elemencs (PEs) char are interco nnected (Figure 1). The strength of these connections is attenuated by weigh cs wji• chat can be altered co reflect rhe process of learning chat occurs in narn ral neural networks. However, both the structure and operation of artificial neural networks are only crude approximations co their narnral counterparcs, and hence their capabil ities are limited co mpared wich chose of narnral neural netwo rks. W hile rhe fi rst researchers into artificial neural networks cried co understand and

ANNs are a powerful tool for prediction and modelling of hydrologic and water quality variables. compared with chat of conventional computers, the highly parallel narn re of the neuronal network enables the brain co perfo rm numerous casks char co nventional computers have difficulty with, such as recognising faces. As che brai n learns, the strength of che connections between neurons is altered, reinforcing neuronal pathways chat are used repeatedly.

replicate che operation of the brain as closely as possible, the majority of recent research efforts has focused on the development and application of artificial neural networks as a computational cool for forecasting and pattern recognition. When viewed from chis perspective, artific ial neural networks have many sim ilarities with conventional statistical models. A number

of researchers have compared che structures and capabilities of artificial neural networks and co nventional scaciscical models and have fo und chat many existing scaciscical models can be represented in artificial neu ral network fo rm (Cheng and T icceringco n 1994). T his can best be illustrated by considering che multi -layer percepcron , which is rhe most popular artificial neural network archi tecture in use today (Figure I). As che name sugges ts, multi-layer percepcro ns co nsist of a number of layers of interco nnected processing elements, incl udi ng an input layer, one or more hidden layers and an output layer. The input from each PE in the previous layer (x;) is multiplied by a con nection weight (wi;) . Ac each PE, che weighced inpuc signals are summed and a bias (0i) is added (Equation 1) . T his combined inpu t co node j (Ii) is then passed through a non-linear transfer function (f(.)) co produce che ourpuc of che PE (yj) (Equation 2). T he ou tput of one PE provides the input co the PEs in the next layer. Ij=L wj;X;+8j summation (l) Yi=f(Ij) transfer (2) The simplest configuration of a multilayer perceptron consists of a netwo rk with one input, one output, no hidden layers

water

DECEMBE R 2004 55


and a linear transfer function with a slope of 1 (Figure 2). This artificial neural network is equivalent to a linear regression model. The connection weight (w 1) and bias (8) are eq ual to the slope and intercept of the regression line, respectively. By including additional nodes in the inpu t layer, the arti ficia l neural network model is equivalent to a mul tiple linear regressio n model, and by changing the transfer fu nction from linear to logistic, the artificial neural network is equivalent to a logistic regression model. The dimensionality and degree of non-linearity of the model can b e changed further by the inclusion of one or more hidden layers, different numbers of nodes in each of these and different types of non-linear transfer functions at each node. While a simple linear regressio n model attempts to obtain a straight line that best fits a sec o f data points in cwo dimensions, an ANN model, in its general form, attempts to ob tain a high ly non-linear surface that best fits a set of data points in multi-dimensional space. In a linear regression model, calibration consists o f ch oosing the model coefficients (i.e . che slope and intercept of a line) so that the error between th e model outpu ts (i. e. theyvalues obtained from the straight line given a set of x-values) and the correspondi ng actual values is minimised. The same principle is used in che cali bration (train ing) of ANN models. It is simply an op timisation process in which the model co efficients (i.e . the connection weights and b ias values) are adj usted in an attempt to minimise che error between the outputs p redicted by che model and the co rresponding historical values. Although che simpler ANN models are not significantly different from a number of standard scaciscical models, they are an extremely valuable modelling tool for the followin g reasons: 1. The form of ANN models does not have to be chosen a priori. When conventional scaciscical models are used, che available d ata are used to estimate che unknown model parameters (i.e. the values o f the slope and intercept in the case of a linear regress ion model) on ce the form of che model (e.g. linear, quadratic, exponential) has already been chosen by che modeller. Choosing the b est model form is a relatively simple cask wh en dealing with a model with a single input and a single output, as the underlying relationshi p in the data can be visualised readily. However, when dealing w ith models w ith multiple in p uts, this is no longer che case, and it is extremely difficult to choose che best model form. W ith ANNs, th e available data are gen erally used to

56 DECEMBER 2004

water

transfer function

Y,

---Y--x

processing element

I

weight

I

output

input

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Figure 2. Artificial Neural Network Representation of a Li near Regression Model. d etermine the form of che model that gives the best fit, as well as to estimate the unknown model parameters. Consequently, th e model structure char b est suits the available data is chosen. 2. ANNs provide a unifying framework for develop ing a range of pred ictive models. As certain types of ANNs have been proven to be un iversal fun ction approximators, pro vided sufficient degrees of freedom (i.e. co nnection weights and b ias values) are available (Hornik et al. 1989), ANNs can be used to implemen t a wid e variety of known (and q uite possibly yet unknown) statistical models simply by changing tra nsfer functions and the number of hidden nodes. In addi tion, multiple inputs and outputs can be incorporated with ease. As a res ult, ANNs have placed complicated statistical models within the reach of practitio n ers (Maier and Dandy 200 06).

Application of ANNs in Hydrological and Water Resources Modelling As a result of their high degree of nonlinearity, universal funct ion approximation

ability and ease of implemen tatio n, ANNs have been used increasingly fo r prediction and fo recasting in a number of areas, including hydrology and water resources (ASCE Task Committee on Application of Artificial Neural Networks in H ydrology 20 00; D awson and Wilby 2001 ). Maier and Dandy (20 00 6) provided the first com prehensive review of the use of ANNs for hydrological and water resources modelling, in which they examined 43 papers pu blished in international journals between 1992 and 1998. Dawson and Wilby (2001 ) used che data fo rmat introduced by Maier and Dandy (20006) as a template fo r reviewing 51 journal and conference pap ers specifically on che use of ANNs fo r modelling rainfall-runoff and fl ood forecasting, and Bowden (2003) extended the work o f M aier and Dandy (20006) to include journal papers up to the end of 2001. Of the 152 papers reviewed by Bowden (20 03), 38% applied ANNs to flow forecast ing, 26% used ANNs for water quality modelling (e.g. algal con centrations, cyanobacterial concentrations, chlorophyll-a,

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cryptosporidium, giardia, nitrate, nitrite, ammonia, phosphate, pesticide, total volatile organic compounds, sulphate, salinity, pH, macroinverreb rares, colour, potassium chloride, residual chlorine and temperature), 20% developed ANN rainfall forecasting models, 6% used ANNs to forecast water levels, 3% applied ANNs to rhe prediction of soil moisture content, while rhe remaining 7% of papers developed ANN models for miscellaneous applications (e.g. predicting specific yield, classifying hydrologically homogenous regions, predicting pan evaporation), as shown in Figure 3. For the studies in which comparisons were made between the performance of ANN and more conventional statistical models, ANNs generally performed better than, or as well as, the traditional models.

Case Studies In this section, successful ap pl ications of ANNs to a range of case studies are presented to illustrate the versatility and utility of ANNs for hydrological and water resources modelling. Maier and Dandy (1996) used salin ity, flow and river level data at a number of locations to develop an ANN model that was capable of forecasting sal inity in the River Murray at Murray Bridge, South Australia, 14 days in advance. M urray Bridge is an important location, as ir is one of the sites at which water is pumped ro Adelaide via the Murray Bridge to Onkaparinga pipeline. Forecasts of salinity at this site could be used to assist in deciding when to pump water from the River Murray so as to reduce the average salinity of the water delivered to consumers. The 14 day forecasts obtained fo r independent validation data from 1988 to 199 1 are shown in Figure 4. I t can be seen that the 14 day forecasts obtained are very useful, as they predict rhe major fluctuations in salini ty without significant delay. Maier and Dandy (1997) and Maier et al. (1998) used ANNs to forecast cell counts of the cyanobacrerium Anabaena spp. in the River Murray ar Morgan, South Australia, four weeks in advance. Potential model inputs considered include colour, turbidity, water temperature, flow, soluble phosphorus, coral phosphorus, oxidised nitrogen and coral iron. The occurrence of high cell counts of Anabaena at Morgan is a significant water supply operational problem, as a water treatment plant is located there and water abstracted ar chis point is delivered to rhe cities of Pore Pirie, Pore Augusta and Whyalla via the MorganWhyalla pipeline. The results obtained by

58 DECEMBER 2004

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Figure 4. 14-day forecast o f sa linity in the River Murray at Murray Bridge, 19881991. Maier and Dandy (1997) for independent validation data are shown in Figure 5 and indicate char rhe ANN model was able to successfully forecast th e relative magnitude (e.g. cell counts greater or smaller than 1,000 cells/mL) and riming of bloom events of Anabaena, thereby providing ample warning of potential water quality problems. Maier et al. (2004) developed ANN models for predicting the optimum alum dose required to achieve pre-determined created water quality levels (turbidity, colour, UVA-254), given certain raw water quality levels (turbidi ty, p H , colour, UVA254, alkalinity, DOC). They also developed ANNs for predicting treated water quality parameters (turbidity, colour, UVA-254, pH, residual aluminium), given the quality of rhe raw water (turbidity, pH, colour, UVA-254, alkalinity, DOC) and rhe applied alum dose. These models can be used in lieu of expensive and timeconsuming jar resrs. The results obtained for independent validation data indicated

that the ANN models are successful at predicting optimal alum doses, as well as treated water quality parameters, over a wide range of conditions (Figure 6). The results obtai ned using the ANN approach compared favourably with those obtained by van Leeuwen et al. (1999), who used a more traditional regression app roach. Bowden et al. (2005c) used ANNs to forecast chlorine residuals in th e Myponga trunk main at Aldinga Road, South Australia, 24 hours in advance, using upstream chlorine residuals, water temperature, fl ow, turbidity and pH as potential model inputs. As can be seen in Figure 7, the ANN model was able to forecast chlorine residuals with great accuracy. This could be used to assist water quality managers with their effo rts of maintaining adequate chlorine residuals in rhe water distribu tion system.

Future Directions and Challenges The success of ANNs for hydrological and water resources modelling has been

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well documented. T hey provide a unifying framewo rk fo r implementing a range of soph isticated, non-linear sraciscical models. As ANN s are uni versal function approx imators, they are ca pable of findi ng relationships between potentially highdimensional, highly non-linear data secs, if such relationships exist. In addi tion, the optimal model fo rm is determined from the data themselves, thereby eliminating the need to choose an approp riate fun ctional fo rm of the relationship a priori. Th e latter is extremely difficul t to do, particularly when dealing with high-dimensional, nonlinear relationshi ps. A number of co mmercial softwa re packages are ava ilable and can be used fo r the development of ANN models. However, there are a number of comm on pi tfalls in the developm ent of ANN models. In fact, th e application of ANNs in practice is restricted by th e lack of a comprehensive methodology fo r their developm ent. Maier and Dandy (2000a) outli ned the seeps that need to be fo llowed in developing ANN models for prediction and fo recasting, including rhe choice of perfo rm ance criteria and data secs, data preprocessing, che choice of model inputs,

architecture and calibration method and model validation. While there are many available options at some of these steps (e.g. model architecture, calibration methods), systematic approaches fo r data division and model input determination have only been developed recently (Bowden et al. 2005a; Bowden et al. 200 2; Bowden et al. 20056). In order to make ANN approaches more accessible, the auth ors are currently writing a book on their proposed ANN model development meth odology, including software modules ro implement each step of the model development process. Another area chat requi res furth er research is the inco rporation of uncertainty in to ANN models, so that predictions with appropriate confidence intervals ca n be made. Kingston et al. (2005) used a Bayesian approach fo r estimating ANN co nnection weights, which enables predictions ro be made with known co nfidence limi ts. Finally, the question of whether ANN models can be used to obtain insight in to underlying physical processes needs to be addressed. So me attempts have already bee n made ro extract knowledge from calibrated ANNs Qain et al. 2004; Kingsto n et al. 2005; Maier et al.

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2000; W ilby et al. 2003), but research in chis area is only in its infancy.

The Authors Holger Maier is Senior Lecturer in the School of Civil & Environmental Engineering and Associate Dean (Learnin g and Teaching) in the Faculty of Engineering, Computer and Mathematical Sciences at the University of Adelaide, Adelaide SA 5005, Australia, email: hmaier@civeng. adelaide.edu. au. Graeme Dandy is Pro fesso r of Ci vil an d Environmental Engineering in the Faculty of Engineering, Computer and Mathematical Sciences at the University of Adelaide. He is also Interim CEO of the Internacional Centre of Excellence in W ater Resources Management established by the Commonwealth Government. Email: gda ndy@civeng.adelaide.edu.au References ASCE T ask Committee o n Application of Artificial Neural Nerwo rks in Hydrology. (2000) . "Artificial neural networks in hydrology. II: Hyd rologic applications." Jou rnnl of Hyt!rologic Engineering, ASCE, 5(2), 124- 137 . Bowden, G. J. (2003). "Forecasting water resources variables using artificial neural

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networks," PhD Thesis, T he U niversity of Adelaide, Adelaide. Bowden, G. J ., D andy, G . C., and Maier, H. R. (2005a) . "I nput de renn inarion fo r neural network models in water resources applicat ions: Parr 1 - Background and methodology." Journal ofHydrology, in press. Bowden, G. J., Maier, H. R. , and Dandy, G. C. (2002). "Optimal division of data fo r neural network models in water resources applications." Water Resources Research, 38(2), 2-1 2- 11 (I0. 1029/2001WR000266) . Bowden, G . J., Maier, H . R., and Dandy, G . C. (20056). "I nput determination for neural network models in water resources appl ications: Part 2 - Case study: Forecasting salin ity in a river. " journal of Hydrology, in press. Bowden, G . J., N ixon, J .B. , D andy, G . C., Maier, H. R. , and H olmes, M. (2005c). "Fo recasting chlorine residuals in a water d istribution sysrem using a general regression neural nerwork." Mathematical and Computer Modelling, accepted . Cheng, B., and Titterington, D. M . (1994) . "Neural networks: A review fro m a stat istical perspective." Statistical Science, 9(1) , 2-54. Dawson, C. W., and W ilby, R. L. (2001). "Hydrological modelling using artificial neural networks." Progress in Physical Geography, 25(1), 80-108 . H orni k, K., Srinchcombe, M., and White, H . (1989). "M ulti layer feedforward networks are u niversal app roximacors." Neural Networks, 2, 359-366. Jain, A., Sudheer, K. P., and Srinivasulu, S. (2004). "Jdenrificatio n of physical processes inherent in artificial neural network rainfall runoff models." Hydrological Processes, 18(3), 571-58 1. Kingston, G . B., M aier, H. R., and Lambert, M . F. (2005). "A probabilistic method to assisr' knowledge extraction from artificial neural networks used fo r hydrological predict ion."

Mathematical and Computer Modelling, accepted. Maier, H . R., and Dandy, G. C. (1996) . "The use of artificia l neural networks for rhe prediction of water quality parameters." Water Resources Research, 32(4), 10 13-1022. Maier, H. R., and Dandy, G. C. (1997) . "Modelling cyanobacteria (blue-green algae) in the R iver M u rray using artificial neural networks." Mathematics and Computers in Simulation, 43, 377-386. Maier, H. R., and Dandy, G . C. (2000a). "Application of Artificial Neural Networks to Forecast ing of Surface W ater Q uality Variables: Issues Applications and C hallenges." Artificial Neural Networks in H ydrology, R. S. Govindaraju and A. R. Rao, eds., Kluwer, Dord recht, T he Netherlands, 287-309. Maier, H. R., and Dandy, G. C. (20006). " N eural networks for the prediction and fo recasting of water resources variables: a review of modelling issues and applications. " Environmental Modelling and Software, 15, 10 1- 124. Maier, H. R., Dandy, G . C., and Burch, M. D . (1998). "Use of artificial neural networks for modelling cyanobacteria Anabaena spp. in the River Murray, South Australia." Ecological Modelling, 105, 257-272. Maier, H. R., Morgan , N., and C how, C. W. K. (2004) . "Use of artificial neural networks fo r

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Figure 6. Actual and predicted values of treated water qua lity parameters and optimal alum dose. p red icting opt imal alum doses and treated water quali ty parameters." Environmental Modelling ant! Software, 19(5), 485-494 . Maier, H . R., Sayed, T. , and Lenee, 8. J. (2000). "Forecasting cyanobacterial concentrations using B-spline networks." journal of Computing in Civil Engineering, ASCE, 14(3), 183-189. van Leeuwen, J ., Chow, C. W. K., Burs ill, 0 ., and D rikas, M. (1999). "Empirical mathe-

mat ical models and artifi cial neural networks for t he determination of alum doses fo r t reatment of southern Australian surface waters." j Water SRT -Aqua, 48 (3), 115- 127 . Wilby, R. L. , Abraharr, R. J ., and Dawson, C. W. (2003). "D etection of conceptual rainfallrunoff processes inside an artificial neural network." Hydrological Sciences Journal, 48(2), 163- 181.

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HOUSE WATER EXPERT: WATER MANAGEMENT SOFTWARE FOR HOUSEHOLDS A Grant, V G Mitchell, E Dell'Oro Summary The CSIRO Urban Water ream has developed the software package House Water Expert (HWE), which can be used to improve water management for a standard suburban residential household. H WE calculates town water consum ption, stormwarer discharge and wastewater discharge fo r a household block. Users enter property derails via a rich graphical interface to evaluate their current water management practices and then in vestigate ways of improving water management around the hom e. Res ults are continually calculated so use rs can quickly ascertain rh e impact of proposed water improvements. Examples of improvements include increasin g the water efficiency of appliances; installing a secondary water supply such as rainwater, greywarer, recycled water or bo re water; and replacing concrete with soil to lower stormwarer runoff. Hom e owners, high school students and anyone interested in improving water management around the home are the primary target audience. HWE could also be used for capaci ty building withi n rhe water industry. Any organisation promoting improved residential water management may find H WE a usefu l tool to raise awareness and understanding of household water management. A national version will be free to use via the web in the coming weeks (email Andrew.Grant@csiro.au for fur ther derails) . CSIRO are keen to build on rhe approach used for developing HWE and are willing to devel op more powerful specifi ed versions of HWE in partnership with other organisations.

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An educational tool with potential for more specific applications. In "Tell Us Abou t Your Home" mode, derails are input about the user's own property such as how many people live in the house, how long each ind ividual spends in rhe shower, how often rhe garden is watered and the efficiency raring (i.e. 'A' raring) of the water appliances. T o make the program as user-friendly as possible, in fo rmation is entered via a rich graphical interface with default values auto matically entered fo r a 'standard' househo ld. Users drag on items such as rainwater ranks, washing machines and garden beds and then input derails about the item via a pop up screen co ntaining a series of questions.

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Description There are three disti nct operating modes in HWE: Mode 1: Tell Us About Your Home Mode 2: Make Home Water Improvements Mode3: Game Mode In Mode 1, derailed information about th e home is inpu t and th e home is modeled; Mode 2 is where water management improvements are investigated and compared with results from Mode I ; and Mode 3 is where a user can have some fu n and play games whilst educating themselves about water management.

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PASS™ Our PASS™ is a "new generation" coagulant which: • Forms floe in low turbidity water (including distilled water) • Hydrolyses very quickly • Is not a Dangerous Good (pH approximately 4, Basicity 54%) • Lowers alkali costs • Has been used in water and wastewater treatment plants in Canberra, Melbourne, Ballarat, Gippsland and elsewhere • Other industrial applications including pulp and paper • Also available is our new PASS™-C

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DECEMBER 2004 61


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As the user inputs information, results on the amount of town water consumed, stormwater ru noff produced and wastewater d ischarged are continually updated allowing the user to immediately assess the impact of each water appliance on the water fluxes of their home. Once the user has represented their own home in HWE they enter Mode 2, " Make Home Water Improvements", where they can investigate ways of improving water management around the home. Techniques which are at the users' fingertips for saving town water are rainwater ran ks, greywater diversion systems, on-site treatment systems, water efficient appliances and groundwater bores. To reduce the volume of stormwater runoff leaving the property, paved surfaces can be replaced with pervious surfaces or roof runoff can be d irected towards the garden or rainwater rank. To reduce the volume of wastewater leaving the property, greywarer diversion systems, on-sire treatment systems and water efficient appliances can be installed. Users may also consider changing their water consumption behaviour (eg. raking shorter showers or watering the garden less) or even changing the number of people living in the house. Whilst making imp rovements to the home, the user can go to the results screen at any stage to see the impact of the improvement ideas they have trialled. The resul ts screen shows the volume of water consumed by each water appliance and also the amount of water consumed by each individual. If any alternative water sources are being used, the results screen will detail the reliability and quantity of water supplied from each source. Game Mode offers a less time consuming way of learning about home water management. Different scenarios in Game Mode challenge users to find ways of reducing town water supply, stormwater runoff and wastewater output in a default land block. In a race against the clock, users have to add water efficient appliances, rainwater tanks and replace impervious surfaces with pervious surfaces. Game Mode would be ideal for school students and can also provide useful pointers to all users.

Algorithms HWE is primarily a communication and education tool. Effective communication and education requires accurate modelling, however accurate modelling should not come at the expense of an intuitive, fun-to-use interface and rapid computation. As the target audience is wide ranging,

62 DECEMBER 2004 water

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Decisions also had to be made about which end uses and alternative technologies were to be included and which were to be left our. Jrems were included in the program if they served a significant educational value or were important for modelling. This meant virtually every end use at a household scale is included; the exceptions being pipe leakages, miscellaneous outdoor use, pavement washing and pet use. As many alternative technologies as possible were included to maximise the educational value. Waterless toilers can be selected, as can greywater diversio n systems with optional 24 hour d rain capabilities. On sire treatment systems can treat all forms of greywacer and blackwater; bore water can be pumped from underground; and rainwater tanks, with the option of first flu sh devices, are also included . If yo u would like detailed information on HWE's algorith ms, a report tided Explanation ofAlg01¡ithms is included with the program.

unnecessary complexity has been avoided and in developing HWE's algorithms, trade offs between modelling accuracy and program usability were made. Length of time-step is an important consideration for modelling events that occur infrequently or without a defined pattern. The most sensitive item to computational time step length in HWE is the rainwater rank. HWE uses a one day time-step. Whilst time-steps shorter than one day would improve accuracy, the improved accuracy was deemed unjustified compared to the reduction in computational speed. A longer time-step such as a week or a month was deemed to reduce accuracy too much. The National Water Conservation Rating and Labelling Scheme, of 'A ratings', provides some degree of modelling accuracy togeth er with educational value. HWE can act as a communication and education tool by informing the public about 'A ratings' and the potential water and energy savings that come with higher rated products. In addition, 'A ratings' also provide a solid modelling platform because d ifferent 'A rating' classifications have specified efficiency ranges. Nor every variable can be as easily defined as an 'A rating' and in some instances, modelling accuracy had to be traded fo r program usability. For example, washing machine 'A ratings' are based on a fu ll load set to "normal wash" and HWE assu mes that each load is a "normal wash ".

Further Development A free national version ofHWE will soon be available and CSIRO is keen to develop localised and enhanced versions. Localised versions of HWE would be mo re powerful than a national version because they could contain specific local information such as regulations and climate fi les. HWE function could be enhanced by integrating other aspects of home water management such as energy, chemical usage and health risks.

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HWE does not have inputs other than 'normal wash' because requiring the user to choose how many super, normal, hand, woollen and delicates loads they complete each week was considered too onerous a cask. This decision reduces program accuracy but maintains p rogram usability. This type of decision was required for many HWE algorithms.

Relevant climate files, tailored water rips and information about local regulations are just some of the benefits of a localised version of HWE. The national version contains only one climate file for each major city in Australia, whereas a localised versio n, say for Sydney, could contain a number of climate files which represent the variance in rainfall from Campbellfield to Richmond and from Karoomba to Bondi. In addition, information about local regulations on rainwater, bore water, wastewater and greywater use rogether with local initiatives about water effi cient appliance rebates could be included. A


URS Senior Water Resources Engineer OR Play a

Outdoor Wator Usago

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URS Corporation is a leading Engineering and En vironmenta l Services company with more than 25,000 professional staff world w ide, focusing on areas such as w ater and wastewater, i nfrastructure, planning and development, environmental and geotechnical engineering, hydrogeology, geology, mining, marine, oi l and gas. URS Australia has 10 offices n ati onally and a staff of 600.

localised version of HWE would make a val uable comm unicatio n, education and marketing tool. The current version focuses on the stormwacer, wastewater and imported water aspects of water management; however, water management involves many more consid erations. Energy consumption, chemical usage analys is, economic analysis, health ris k guidance for alternative water sources, so il impact assessments and embodied water and energy are just so me of rhe possibilities for an enhanced version of HWE. Th e more dimensions of wa ter m anagement rhar can be included in HWE, the more powerful a too l it will become.

Industry Partnership Opportunities CSIRO is keen to develop enhanced and localised versions in partnership with industry. T he CSlRO Urban Water ream th erefore invites you to use rh e free national version ofHWE (se nd an email to Andrew.Granr@csiro.au for derails) and to co nsider ways you could tailor HWE to your organisation's needs. Ta ilored versions of H WE could incl ude energy consumption , gu idance on local regulations, a great number of climate files for a region, guidan ce on local regulati ons, derails of local initiatives, eco nomics and health risk guidance among ochers. Our i1n aginacion is the limit! Contact Andrew Grant at CSIRO if you are interested in exploring partnership opportunities.

Conclusion HWE is a simple-co-use, intuitive software char is ideal fo r home owners, high school students and anyone interested in improving water management around the home. Organisati ons keen on promoting rainwater ranks, water efficient appliances, non-structural demand management, greywacer diversion systems, water sensitive urban des ign and on-s ite treatment systems may use the free national version which will be available via the web in the coming weeks (contact Andrew.Grant@csiro.au for derails). T his version wi ll be availab le as a downloadable installation pac kage which runs on recent W indows Platforms. A 'Web Based' ver sion and 'Web Executable' vers ion are currently being developed.

With continued growth in t heir NSW Water Resources Group, th ey now seek an experienced Senior Water Resources Engineer to undertake and manage a range of surface water related projects, w ith particular emphasis on fl ood related stud ies, hydrologic / hydrau lic modelling, mapping appl ications and complex floodplain mod el ling . You will be qualified with a Civil or Environmental Engineering Degree, preferably w ith a Masters Degree, and w ill have a minimum of 8 yea rs post graduate experience. To be successful in this position you wi ll require a m inimum of 3yrs previous Australian based experience wo rking in a similar position, as wel l as an established network of industry contacts Your responsibilities will include:

• Undertake floodplain management projects, including cl ient li aison, f inancia l control, coordinati on and supervision of staff, consultant s and sub-contractors. • Prepare detailed reports and proposa ls for commercial project work including defining th e scope of work, cost and resources estimates, review and negotiate (as requ ired) contract conditions and requirements. • Train junior staff on project wo rk, prepare and present in-house seminars, etc. • Assi st in marketing of specialist technical competencies and mainta ining the company's profile as a leader in water resources act ivities. Voted number 1 of the Top 500 Design firms for 4 consecutive years, this is an excellent opportunit y to join a global leader where you can expect excellent benefits, ongoing trai ning and support and a friendly working environment.

To apply for this position, email your resume to rbransky@dcrecruitment.com.au or contact the Director Raelene Bransky on (02) 8904 0066 for a confidential chat.

The Authors Andrew Grant is a scientist in CSIRO 's Urban Water ream (Andrew.G rant@csiro.au); Grace Mitchell is a senior research fellow at Monash University (grace.micchell @eng.monash.edu. au) and Eric Dell'Oro is a computer programmer within CSIRO's Ur ban Water ream (Eric.DellOro@csiro.au).

water

DECEMBER 2004 63


WATER QUALITY MONITORING IN RESERVOIRS IN SOUTHEAST QUEENSLAND M A Burford, K McNeale, C Krogh, M O'Donohue, T Packer, T McAlister Abstract A study of the water quality mo ni toring programs across six water supply reservoirs and three water authorities (Redland W ater and Waste, Gold Coast Water, SEQWater) in southeast Queensland has fo und considerable di fferences in the parameters measured, and sampling p rotocols .. Preliminary analysis of the historical data for water quality parameters (relevant to algal bloom problems) showed that total nitrogen and chlorophyll a concentrations were highest in reservoirs with catchments having the highest percen rage agriculture (North Pine, Somerset and W ivenhoe Dams). In contrast, total phosphorus did nor show chis trend bur was highest in th e catchment with che h ighest urban development (Leslie Harrison Dam). Further analysis of the histo rical data is warranted co compare catchm ent ch aracteristics with water quality . In o rder to more effectively co mpare water quality in the reservoirs, a study is planned co sample the reservoirs using che sam e sampling protocols, riming of sampling, parameters measured and analytical techniques. This will allow a more direct comparison and aid che industry in identifying che factors responsible for promoting algal blooms in reservoirs

Introduction Maintenance of high quality water in drinking water reservoirs is a key issue for reservoir managers. Co nsiderable resources are allocated co monitor water, and co

Table 1. Summary of catchment and dam statistics for the six reservoirs. Parameter

Catchment Area (ha) Submerged Area (ha) Capacity of Reservoir@ FSL (ML) Mean Depth (m) Reservoi r/ Catchment Area(%) Bloom Incidences

Little Nerang

Hinze

Leslie Harrison

North Pine

Somerset

Wivenhoe

5,647

14,594

11 ,732

34,733

134,156

571 ,638

55

920

470

2,181

4,2 12

10,750

9,280

163,500

24,800

215,000

16.7

17.8

5.3

9.9

9.0

10.8

1.0%

6.3%

4.0%

6.3%

3.1 %

1.9%

every few years

every few years

every few years

annual

annual

annual

reservoirs is algal blooms. Depending on the sp ecies, blooms may create low oxygen conditions, taste and odour p roblems, or produce toxins harmful co humans and animals. Water reservoirs have created an artificial enviro nment conducive co algal growth, and particul arly cyanobacreria, with calm waters, high light availability in surface waters and external nutrien t inputs. In southeast Queensland ch is problem is exacerbated by warm summers, high nutrient inputs from large rain events, and infrequent flu shing Oones and Poplawski 1998). Australia's water reservoirs are owned and managed by a large number of organisations, both private and government, and, in general, water quali ty monitoring programs are developed on a reservoir by reservoir basis. A wealth of

Despite differences in monitoring protocols some clear trends were found across the region. A study is planned to compare the reservoirs using the -same sampling techniques. trigger action during episodes when water q uality d eteriorates. This ensures th at human and environm ental health is nor compromised. One of che water quality param eters of concern for many Australian

64 DECEMBER 2004 water

historical water quali ty data exists, however it is often the case char the informatio n is archived without che rime or resources co analyse the data for factors char might be responsible for initiating algal blooms.

380,000 l, 165,000

Addition ally, inform ation exists on catchment land use, soil types etc wh ich can have a significant effect on nutrient and suspended loads in rivers and hence algal blooms in downstream reservoirs (Ulrich 1997, Harris 2001, Knoll eta!. 2003). In light of this, a study was recently conducted by researchers at the Centre for Riverine Landscapes at Griffith University, collaboratively with water managers at Gold Coast Water, Redland Water and Waste and SEQWarer co exam ine their water


URS

quality monitoring programs and where possible, analyse the historical water quality data and catchment land use.

Senior Process Engineer Water/Waste Water

The reservoirs concerned The water quality monitoring programs were examined for six water supply reservoirs in south-east Queensland: Leslie Harrison Dam - managed by Redland \Xlater & Waste Litde Nerang Dam - managed by Gold Coast \Xlater Hinze Dam - managed by Gold Coast \Xlater North Pine Dam - managed by SEQWater Somerset Dam - managed by SEQWater Wivenhoc Dam - managed by SEQWatcr Leslie Harrison Dam is a supplementary drinking water supply for an underground water supply from Stradbroke Island, Hinze Dam supplies most of the drinking water requirements for rhe Gold Coast, while Little Nerang is a secondary supply. North Pinc Dam supplies a number of regional centres including Pine Rivers and Redcliffe as well as Brisbane City, while Wivenhoe and Somerset Dams are the main drinking water supply for Brisbane city, as well as supplying the Gold Coast, Logan and a number of regional areas. Dara are summarised in Table I. The reservoirs vary in volume from 9,300 ML for Little Nerang Darn up to 1,165,000 ML for Wivenhoe Dam, and have mean depths ranging from 5.3 m for Leslie Harrison Dam up to 17.8 m for Hinze Dam when full (Table 1). The catchment areas also vary markedly between reservoirs from 5,650 ha for Little Nerang Dam up to 571,638 ha for Wivenhoe Dam. There is a range of catchment land uses across the six reservoirs (Fig. 1). In the case of Little Nerang, Leslie Harrison and Hinze Dams, the proportion of the land used for agriculture is low ( 1213%), with most of the area dedicated to forest. The forest is predominantly natural bush but some catchments also have a significant proportion of managed forest. In the catchments for North Pinc, Somerset and Wivenhoc Dams, the proportion of agricultural land is considerably higher (29-49%). This is principally grazing land, with little broadacrc or intensive agriculture. Leslie Harrison Dam is rhe only reservoir with a substantial level of rcsidenrial development (..-20%) in rhc catchment. The degree to which a reservoir is affected by the catchment land use is not just related to the activities within the catchment, but also to the volume of the reservoir relative to the area of the catchment. Therefore those reservoirs at highest risk are likely to be those with the lowest reservoir volume relative to catchment area, coupled with the highest human impact, e.g. agrirnlturc, in the catchment. An analysis of the data from the six reservoirs suggests that Wivenhoe Dam is the most vulnerable reservoir in terms of water quality, despite being the largest water supply in southeast Queensland. Monitoring

Approximately 20 years of historical records exist for 30 water quality parameters across these reservoirs. There was a high level of inconsistency in the monitoring program with 14 comparable parameters, related to algal blooms and their causes, being identified as commonly measured by all water authorities for rhe period from July 1997 ro December 2003: bloom incidences cyanobacterial cell counts algal roxins taste and odour compounds total nitrogen

URS Corporation is a leading Engineering and Environmental Services company with more than 25,000 professional staff world wide, focusing on areas such as water and wastewater, infrastructure, planning and development, environmental and geotechnical engineering, hydrogeology, geology, mining, marine, oil and gas. URS Australia has 10 offices nationally and a staff of

600. With continued growth in their NSW Water Resources Group, they now seek an experienced Senior Process Engineer to undertake and manage a range of Water/Wastewater projects including D&C and JV projects, with particular emphasis on Biological Nutrient Removal, membrane technologies, residuals management, modelling, performance and functional specifications and treatment plant commissioning. You will be qualified with a Civil/Environmental or Chemical Engineering Degree, preferably with a Masters Degree, and will have a minimum of 8 years post graduate experience.

To be successful n this position you will require a minimum of 3yrs previous Australian based experience working in a similar position, as well as an established network of industry contacts. Your responsibilities will include:

• Undertake Water/Waste Water treatment projects, including client liaison, financial control, coordination and supervision of staff, consultants and sub-contractors and Joint Venture partners. • Prepare detailed reports and proposals for commercial project work including defining the scope of work, cost and resources estimates, review and negotiate (as required) contract conditions and requirements. • Train junior staff on project work, prepare and present in-house seminars, etc. • Assist in marketing of specialist technical competencies and maintaining the company's profile as a leader in'water resources activities. Voted number_ 1 of the Top 500 Design firms for 4 consecutive years, this is an excellent opportunity to join a global leader where you can expect excellent benefits, ongoing training and support and a friendly working environment.

To apply for this position, email your resume to

rbransky@dcrecruitment.com,au or contact the Director Raelene Bransky on (02) 8904 0066 for

a confidential

chat.

water

DECEMBER 2004 65


water • total phosphorus

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120

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100

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80

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Additio nally, there were differences in the number of sites sam pled in-lake, sampling dep ths, and rhe methods for m easuring river and creek nutrient inputs . Sampling frequency varies between weekly and fo rtnightly. The analytical methods used were nor exam ined in derail bur, on ce agai n , there appeared to be considerable variab ility.

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Analysis of Historical Data The variabil ity in rhe parameters measured and sampling protocols made co m parisons of rhe historical d ata across reservoirs di ffic ul t. H owever, som e key water quality parameters were identified from most or all rhe reservoi rs, i.e. roral nitrogen, total phosphorus and chlorophyll a (a measure of algal biomass). M ean total nitrogen (T N) and phospho rus (TP) concentrations were calculated fro m surface data at one sire near the dam wall in each reservoir for the period fro m J u ly 1999 to May 2002. These concen trations were com pared with land use in the catch ment. The reservoirs with the highest level of agricul tu re in the catchment had the highest TN co ncentrations (Fig. 2a). Leslie Harrison, N o rth Pine, Somerset and Wivenhoe D am s had si mi larly high concentratio ns whi le Hinze and Little N erang D am s had the lowest TN concentrations. In contrast, T P concentrations were highest and most highly variable in Leslie H arrison Dam (F ig . 26) . T his was the reservoir with the highest proportion of residential area in rhe catchment (~20%) . T here was no evidence of increased T P co ncentrations in the reservoirs with in creased agriculture in the catch ment. T here were considerable d ifferences in the parameters measu red, and rhe methods used in relation to estimatin g abundance and diversity of algae. H owever, clearly there were contrasts in the frequency, intensity and types of poten tially toxic cyanobaccerial blooms char occu r in rhe reservoirs (Table 1). Microcystis and Anabaena b loom incidences have o ccurred infrequently (every few years) at Leslie H arrison and H inze Dam, whi le Cylinclrospermopsis bloo ms o ccurred an nually ar N orth P ine, Somerset and W ivenhoe reservoirs . T here were few

66 DECEMBER 2004

water

Figure 1. The percentag e of different land uses in the catchments across the six reservoirs. p roblems with toxic cyan obacrerial blooms at Lierle Neran g Dam . C hlorophyll a concentratio ns were compared in five of the six reservoirs using summer chlorop hyll data from 1999 to 2002 at the surface at a site nearest rhe dam wall/offrake point (chlorophyll a was nor measu red ar Leslie Harriso n dam). Co ncentratio ns were lowest in Lierle Nerang and Hinze Dams, the two reservoirs with the lowes t %agriculture in the catchment (Fig. 3). No rth Pine, Somerset and W ivenhoe Dams all had comparable mean co ncentrations, with Wivenhoe Dam having the highest variability in concentration s. The reservoirs with rhe lowest ch lorophyll concentrations also had th e greatest mean dep th . Light is an im portant

factor affecting algal growth and therefore deeper reservoirs are likely to have less avai lab le ligh t, and more buffering in temperature changes . T h erefo re in summer, temperatu res in the reservo irs are not likely to be as high , b ut ch is warrants fu rther analysis.

Developing a Collaborative Approach to Water Quality Monitoring T he analysis of rhe historical data has provided some interesting cl ues as to which factors may be prom oting algal b looms, however a more detailed an alysis of the data is needed. Additionally, chis study has highl ighted rhe d ifficu lties in comparing water q uali ty data across reservoirs when different pro tocols are used and d ifferent


water

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parameters measured. In an effort ro develop a more collaborative approach ro water quality monitoring, a study is currently bei ng planned ro undertake periodic simultaneous (i.e. within one co rwo weeks) sampling of key water quality parameters, i.e. TN, T P, algal counts, ch lorophyll a, taste and odour compounds, physical parameters, across all rhe reservoirs. T his would involve using the same protocols for sampling and sample analysis, and standardising the parameters measured. Ir will therefore be poss ible ro more accurately co mpare the warer quality in che reservoirs, and develop a better understanding of rhe factors responsible for promoti ng algal blooms.

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Dr Michele Burford is a Senior Research Fellow at the Centre fo r Riverine Landscapes, Griffith University, Nathan, Q u eensland, email M.burford@griffich. edu.au. Karen McNeale is an Honours Srudenr ar rhe Centre. Carmel Krogh is rhe Manager of Water T rearmenr Operations at Redland Water and Waste, Dr Mark O'Donohue is rhe Water Quality Manager at SEQ Water, Tim Packer is Catchment Manager at Gold Coast Warer, and Tony McAlister is a Director of WBM Oceanics Australia.

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References

25

Harris, G. (200 I) Biogeochemistry of nitrogen and phosphorus in Australian catch111ents, rivers and estuaries: effects of land use and fl ow regulation and co111parisons with global parrerns. Marine and Freshwater Research 52, 139-149. Jon es, G.J., and Poplawski, W. (1998). Understanding and management of cyanobacterial bloo111s in sub-tropical reservoirs of Queensland, Australia. Water Science and Technology 37, 161 - 168. Knoll, L.B., Vanni, M.J. , Renwick, W.H. ( 2003) Phytoplankton primary production and photosynthetic para111eters in reservoirs along a gradient of watershed land use. Limnology and Oceanography 48, 608-6 17 . Ulr ich, K-U. ( 1997) Effects of land use in the drainage area on phosphorus binding and mobility in the sedi111cnts of four drinkingw ater reservoirs. Hydrobiologia 345, 21-39.

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Figure 3. Mean summer chlorophyll a co ncentrati ons (µg / L) for five water reservoirs compared w ith percentage agricu lture in the catc hment.

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water

DECEMBER 2004 67


COMMUNITY VIEWS ON DRINKING WATER QUALITY IN AUSTRALIA'S CAPITAL CITIES N Roseth Background and Methodology

Table 1. Ratings of overall satisfaction with drinking water and its attributes.

• Information sources abom water quality. While the survey enables each participating utility to compare its fin dings to those of other uriliries, its purpose was nor to rank or compare data from city to city.

In its second round of fun ding, the Cooperative Research Centre for Capital cities average Range Water Quality and Treatment 7.2 6.1 - 8.5 (CRC WQT) introduced a social Overall satisfaction research program, ' People's 8.4 7.4- 8.9 Value for money Perspectives', ro add a social/ 7.2- 8.9 Look 8.0 community dimension ro its range 6.6 - 8.7 Smell 7.6 The Findings of scientific and technical programs. 6.9- 8.6 Safety 7.6 The aim of the program is ro give Context Taste 7.1 5 .6 - 8.5 the co mmunity a voice in the In reporting the smdy fin dings, it planning of water services. Ir will is necessary to keep in mind that all randomly drawn from the Electronic W hite enable water managers, regularors and the water utilities participating in this study Pages for each utility. A total of 4, 150 policy makers to understand customers' comply with the Australian Drinking Water people participated in the study - 415 fro m judgement of standards of service and to Guidel ines which cover the physical and each capital city and three ' lots' of 4 15 for manage co mmunity atti tudes, needs and aesthetic properties of water. T his study each of M elbourne's three service providers. expectations. explores com munity perceptions of water Data was collected by way of a specially The firs t project undertaken by rhe quali ty, nor its actual quali ty. developed telephone survey. The interviews People's Perspectives program was a Satisfaction with tap water and its were conducted with a member of the community survey of attitudes to drinking attributes People were asked to rate on a scale of 1 People in Australia's major urban centres take a to 10, (where '0' - 'terrible' and ' 10' clean, safe water supply for granted and are 'excellent') their satisfaction with the water they receive at home. Table 1 shows average generally satisfied with its quality. national mean ratings and rhe range of raring across all capital cities. water quality held by people living in household aged over 18. They rook place T he majority of the surveyed residents Australia's capital cities. All water utilities during September/Ocrober 2002 and lasted were satisfied with tap water quality and serving capital ci ties participated in the on average just over ten minu tes. An gave it an average satisfaction raring of 7.2 study. agency was of 10. Looking at the individual accredited social research our The purpose of this survey was to: commissioned ro select the sample, conduct attributes of taste, smell, look, safety and • Provide a national perspective on views value for money, rap water received the the phone interviews and analyse the data. held by communities in Australia's capital highest raring for its value for money (rared T he survey explored a range of aspects of cities abo ut rhe drinking water they receive. at 8.4 our of ten) and rhe lowest raring for water quality including: • Provide water utilities with rhe ability to its taste, which is rared at 7.1 ouc of ten . • Satisfaction with rap water benchmark their performance in the Safety was rared at 7.6 out of ten . Taste was • Use of rap water alternatives delivery of water services, as judged by their the rap water attribute most strongly • Experience of problems with rap water customers. correlated with views on overall satisfaction • Views on water treatment and • Provide the CRC for Water Quality and with tap water. management Treatment and water utilities with The type of water people drink in formatio n char can be used to Cusromers were asked what kind develop education, commun ication Table 2. Percentage w ho drink mainly tap water and of water they mainly drank at home and promotional materials 1:elaring who mainly turn to alternatives. - tap water or bottled, fi ltered, ro drinking water that are based on Capital cities average % Range% boiled or rain water. (Boiled water understanding of customers' did nor refer ro hot beverages such perceptions, judgements and 60 45 · 88 Tap as tea or coffee; only to water char is concerns. 18 6 - 21 Home filtered boiled before it is drun k.) Table 2 Each water utility provided 10 3 - 19 Bottled shows the percentage of surveyed informatio n descri bi ng its 3 · 13 8 Boiled tap water customers who mainly drink tap geograph ical area of operation. A 0-11 2 Rai nwater water and those who mainly turn to sam pie of 415 residents was

68 DECEMBER 2004

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refereed paper


water alternatives. The table shows the percentage of all capi tal cities as well as the range across chem . The survey indicates chat in choosing the type of water to d rink, capi cal city residents are most likely to rum to tap water. Sixty per cent mainly drink tap water at home. However, some rum to alternatives: 18% main ly drink home-filtered water, I 0% bottled water, 8% boiled cap water and 2% rain water. Peopl e who turn to tap water alternatives were asked to exp lain why they did so. Of chose who drink hom e-fi ltered water, o ne chi rd do so because they believe chat it is safer, cleaner or con tains fewer ger ms than rap water, while another third m entio n doing so because they like the caste of fi ltered water. Of rhe minority who mainly dri nk bottled water, rhe most common reason for drinki ng ir, men tioned by one rhird of chose who do so, is usi ng up water left over in bottles pu rchased wh ile out and about. N ineteen per cent of bottled water d rin kers prefer rhe caste of bottled to rap water and a fu rther 13% because they believe chat bottled water is safer, cleaner or contains fewer germs than tap water.

Table 3. Percentage of people who experienced specific problems with tap water. Capital cities average %

Range %

Chlorine taste/smell

42

32 - 55

Cloudy water

34

18 - 42

Brown/dirty water

23

15 - 35

Warm water from cold tap

23

10-49

Marks fittings

19 13

11 - 3 1

Non-chlorine taste/smell Stains washing

7

2 - 10

'Blue green'

4

3 -8

Caused illness

3

1 -4

Another problem

4

2 -5

9- 20

Among rhe relatively small numbers who d rink boiled cap water, the m ost common reaso n for do ing so, mentioned by 46% of resp o ndents, is che belief chat it is cleaner, safer or contains fewer germs than cap water. Seventeen per cent of chose who drink boiled cap water d id so ou t of habit. Among the very few people who dri nk rainwater, the domi nant reason fo r doi ng so is caste preference.

Experience of problems T h e research explored the exten t co w hich people experience a range of p roblems with their tap water qual ity. The problems invest igated wer e : • Water casting o r smelling of chlo rine • Water having a caste or smell of something other than ch lorine • C loudy water • Brown or d irty water • Warm water coming ou t of the cold cap • Wate r leaving m arks on fittings Water leaving stains on washing Water having a 'b lue green' colour • Water causing illness T able 3 shows the percentage of cus tomers (average and range across cities) who have experienced the above problems in rhe year prior to rhe survey being conducted. Seventy per cent of people had experienced at least one of rhe problems m entioned above. One

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water

DECEMBER 2004 69


water quarter experienced three or more of the problem s. People were also asked how frequently they experienced problems. Among those who experienced problems, rhe majority experienced them on ly sometimes o r rarely. A m inority experienced problems all of the rime. By far rhe most commonly o ccurring problem , experienced in the last 12 months by 42% of people, was water having a chlorine taste or smell. The next most commo n problem was cloudy water, experienced by 34%. Twenty three per cent mentioned each of brown or d irty water and receiving warm water fro m the cold tap. Fewer than one in five experienced the o ther problems. Four per cent experienced 'blue green' water and 3% perceive that the water caused illness. While a consid erable proportion of people experience a range of p roblems with their water at least some of the time, a small minority report these problems to their water utilities. People were more likely to report prob lem s that are perceived to be m ajo r than chose chat were perceived to be 11111101'.

Water management and treatment

People were asked if they were aware ch at ch lorine was added to rhe water, and if so why. T h ree-quarters were aware char ir is used, and of those, the vast majority correctly u nd erstand the reasons for its use. Table 4 shows percentage of people surveyed (average and range) who 'strongly agreed' or 'agreed' to various srarements relating to the management of drinking water in their city. The survey fo und chat levels of trust in the managem ent of water services are generally h igh. Eighty per cent of the people surveyed cake clean rap water fo r granted . Eigh ty nine per cent are confident char there are health standards set for rap water. Eighty rwo per cent crust the authorities to do all chat is needed to ensure char th e water is safe to d rink and 78% are confident that the water is reseed regularly for any problems. Trust in the authorities to inform the public immed iately if they suspected char the water supply becam e unsafe is somewhat lower: 68% believe this to be the case.

Table 4 . Agreement w ith statements about the management of drinking water. Capital cities average Strongly agree and agree %

Range

I tend to take clean tap water for granted

80

76 路 88

I believe that water needs to be treated with chemicals to ensure that it is safe to drink

68

59 路 73

I am concerned that the chemicals used to treat the water moy be harmful

56

43 路 61

More money needs to be spent on improving tap woter q uality in my area

51

27 -65

I am concerned that there might be harmful germs in the water

46

25 -57

I am confident that there are health standards set for my tap water

89

85 - 95

(If agree that standards are set) I a m confident that my tap water currently meets the health standards

87

83 - 94

I om confident that the water is tested regularly for any problems

78

75 - 89

I trust the authorities to do all that is needed to ensure that the water is safe to d rink

82

78 - 88

I om confident that the authorities would inform the public immediately if they suspected thot the water supply became unsafe

68

65 - 77

Despite the fact that all customers receive water chat meets the health standards, there are some lingering concerns about aspects of water quality. Although 68% of surveyed customers believe char the water needs to be created with ch emicals to ensure that it is safe to drink, 56% are co ncerned char the chemicals used to treat the water m ight be harmful. Forry-six per cent are concerned that there might be harmful germs in the water. T h e com munity is d ivided in its view as to whether more mo ney needs to be spent to improve the quality of water: 51 % b elieve th is to be the case.

%

People were asked to rate on a tenp oint scale (where ' O' - 'comp letely d ist rust' and' 10' - 'co mpl etely trust'), rhe exte nt to which they trusted various b odies to give infor mation ab out water quality T a bl e 5 shows mean ratings (ave rage and range). Overall, scientifi c, h ealth and medical experts and fa m ily and fr iends are the most trusted sources of information on water quality. Trust ratings range from 7 .8 our of 10 for the CSIRO to 7.2 for health d epartments. Trust in the water utilities as a source of such informatio n is rared at 7 .0 o ur of 10. Environmental groups receive a racing of 6.9 and the m ed ia 4.9 .

Information sources

Sixteen per cent of the surveyed people have sought in formation on water quality from their water u tility, their doctor or health professional or via rhe Internet. Some of chose who sought inform ation, sought it from more than one source. Of chose three so urces, 8% sought information from rhe doctor, 6% from rhe Internet and 5% from rhe water authority.

In conclusion Despite rhe fact that a considerable proportion of customers have experienced a problem with their water, people in Australia's major urban centres take a clean, safe water sup ply for granted and are generally satisfi ed with its quality. There is a general belief in rhe community that the water is safe, but there is an underlying

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water

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refereed paper


Table 5. Trust in various sources of information about water quality.

CSIRO Scientists Doctors Health Departments Family and Friends Woter authority Environmental Groups Media

Capital cities average

Range

7.8

7.6 · 8.5 7.2 . 7.7 7.3. 7.6

7.4 7.4 7.2 7.2 7.0 6.9

4.9

7.0 · 7.6 6.9 · 7.6 6.4 · 7.7 6.7 · 7.0

4. 8 · 5.1

co ncern abo ut germs in the water and rhe potentially harm ful impact of rhe chemicals used to treat rap water. The study revealed considerable discrepancies in the views of residents of rhe various citi es about all aspects of their drinking water. Several facto rs which are pertinent to the circumstances of som e cities more tha n to others, may contribute to the di ffere nt perceptions held by residents of the various cities. For example: • T he water supply of some cities is sourced from catchments rhar are more pris tine than others. • T he po litical cl imate is more conducive in some cities than in others to governments promoting the quality of the water supply. • A long history of poor water quality in the pasr is likely to linger in people's memory and adversely affect their perceptions long after im provements to water qual ity have occurred. • Warer quality incidents, experienced by so me cities and nor by oth ers, requ ire residents ro boil their dri nking water fo r short periods. Such incidents are known to have a lasting impact on perceptions of water quality and trust in the authori ties. • D roughts affect some cities more than others. They impact on the aesthetics of water and in turn on people's percep tion of water quality. Each water utility participating in this study is now in possession of rhe fu ll and derailed research Findings. Util ities can repeat rhe exercise in th e future ro detect changes in custo mers' perceptions. Surveys such as th is enable custo mers to judge their water provi ders' performance. The challenge fo r water utilities is ro use suc h surveys to 'l isten' ro cusromers' views and concerns, understand rhe reasons fo r the gap between the 'real' and 'pe rceived' quality of water, maintai n comm unity trust, build upo n it and communicate to the public the role of water treatment in secu ring healthy, pleasant drinking water.

The Author Dr Naomi Roseth is the Leader, People's Perspective Program in the Cooperative Research Centre for Water Quality and Treatment (CRC WQT) . The People's Perspecti ve Program is the social research arm of the C RC WQT and adds a comm unity and customer dimension to its array of scientific and technical programs. The Program is currently located in the Institu te fo r Sustainable ruru res, University of T echnology, Sydney. for eleven years, up ro 2004, Naomi was the Ma nager, Customer Research Unit in Sydney Water. The Unit was responsible for exploring commu nity and cusromers' views, concerns and behaviour relati ng to all aspects of the delivery of water services. Naomi holds a PhD in psychology from the Un iversity of New Sou ch Wales. Contact: Phone: (02) 9209 4370; email: naomi.roseth@uts.edu.au

refereed paper

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water

DECEMBER 2004 71


CONSULT, DELIBERATE O.R EMPOWER? L Cole-Edelstein Abstract

INCREASING

T h is paper explores the issues of ' involvement' and 'consu ltation ' and suggests some novel approaches co ach ieving success when working with communities.

Introduction One of the biggest d ilemmas facing chose who wish co invo lve the b roader comm unity in projects o r decision making is choosing the best way to facil itate chat involvemen t. Community involvem ent is widely recogn ised as important. Noc only does it often enhance and improve p roj ect ou tcomes, it also p rovides legitimacy, is often mandated by legislation and is a core activity of so cial responsibility fo r large corporations and governmen t.

LEVEL OF

Public Participation Goal:

Public Participation Goal:

Public Participation Goal:

Public Participation Goal:

To provide the public with balanced and objective information to assist them in u ndersta ndi ng the problems, alternatives and/or solutions.

To obtain public feed back on analysis, alternatives and/or decisions.

To work directly with the public t hroughout the process to ensure that public issues and concerns are consistently understood and considered.

To partner with the public in each aspect of t he decision including the development of alternatives and the identification of t he preferred solution.

To place final decision-making in the hands of the public.

Promise to the Public:

Promise to the Public:

Promise to the Public:

Promise to the Public:

Promise to the Public:

We will keep You informed .

We will keep you

We will work with you to ensure that your concerns and issues are directly reflected in the alternatives developed and provide feedback on how public input influenced the decision.

We will look to you for direct advice and innovation i n formulating solutions and incorporate your advice and recommendations into the decisions to the maximum extent possible.

We will i mplement what you decide.

Example Tools:

Example Tools:

Example Tools:

Example Tools:

Example Tools:

• Citizen Advisory Committees

• Citizen juries

• Consensusbuilding

• Delegated decisions

informed, listen to and acknowledge concerns and provide feedback on how public input influenced the decision.

It is only when you face up to that question that you can then go further to select the appropriate tools.

I have been a community co nsul tation p ractitioner for over ten years and have had che privilege of working in all spheres - as a consumer ad vocate, as a governmen t representat ive and now in the private sector. I n chat t ime I h ave seen che d evelopmen t of the co m m uni ty consultation industry, che establish ment of a healthy industry body and the growing maturation and so phistication of ' che com m un ity' as they engage at d ifferent levels on a wide num ber of projects. One of the issues char co ntin ues to concern me, however, is chat o f rhe role o f

COLLABORATE

CONSULT Public Participation Goal:

H owever, is it appropriate chat communities, stakeholder groups or individ uals have d ecision-m aking in fl uence over your particular project?

Level of Involvement

• Fact sheets

• Public comment

• Workshops

• Web Sites

• Focus groups

• Deliberate polling

• Open houses

• Surveys • Public meetings

72 DE CEMBER 2004

water

• Ballots

• Participatory decision-making © IAP2. All rights r eserved.

Figure 1. The IAP2 Consultation Spectrum. comm un ity involvement will be. I t seems to m e chat chis situation can be rectifi ed, and needs to be ad dressed, by chose undertaking consul tative processes, righ t at the start. I n face, before the stare - when planning any kind of consul racive app roach.

The first step recommended for any involvement process has to be the clarification of what you want to achieve. communities or stakeh old ers in influencing projects or decisions, and che level of expectation chat exists on both sides. We co ntinue to undertake p roj ects based on a m is-align ment of what the impact of

PUBLIC IMPACT

I have used che term ' involvement' deliberately. O n ce you engage with chose o utside the regular sphere of in fl uence on a project, you involve chem . Bue the level of

chat involvem ent needs to be determined by how much influence they can have on the p roject or d ecision . The In ternacional Association for Public Participation (IAP2) h as developed a spectrum for pu blic participation char features differing levels of involvement as a p roject has increasing levels of pu blic impact. Ir p rovid es an excellent starring point when deciding the "what, when and how" about a co nsultation project In my experience, however, very few p rojects in Australia have co llaboration or em powerment as their aim for involvem ent for commun ity or stakeholders. The highest level of involvement is almost always


'consultation' as defined in the spectrum. This level maintains the power balance of the project by keeping decision making in the hands of the proponent, and often leads to a process chat is more about communiry relations than the level of co nsulcacion char the community needs or wanes. Indeed, as the community in general becomes more sophisticated in their ability to participate, we are confronted by an ever-increasing number of 'scakeho lders' demanding a role in influencing decisions and proj ects. This in t u rn has led co a legitimate reexamination of rights, constituencies and co nsensus in decision-m aki ng and project implementation . Almost universally, the focus of any proj ect or decision-making process is che outco me or outputs of the proj ect - the des ign, the siring, the allocation of resources, etc. However when deciding th e appropriate way in which to involve the community - or ocher key stakeholders - it is essential to full y understand the decision making process. Ask who will be making what decisions, and how much influence the input from others is going to be able to have. Jnevirably chis leads to co nsideration of such issues as con sensus, co nstituency, representati on and auth ority. Being clear about the level of involvement before choosing tools thus allows you co choose those tools that are appropriate. What authority does a public meeting have, for example? I would suggest very little. This method of communication is favoured by politicians when the issue is one of their own and scorned when used by their opponents. To stack a meeting with an angry crowd is a lot easier than reaching the 's ilent majority', presumably those quiet souls still at home as the rest of us wrestle it our in draughty halls. As we all know, to motivate people to be involved is often difficult, particularly if the activities through which they can be heard are b ased around meetings, workshops or displays. [ know chat I am passionate about the area where I live but I have to have very high mocivacion to attend a meeting in th e evening after work or fir into my weekend plan s to visit a display depicting changes in our area. le has been interesting to note that the Minister for Roads in N SW has distanced himself from the weight of opposition being expressed through organised groups on a recent motorway extension, questioning the authori ty of chose groups. Instead he has appealed for 'ordinary residents' co come forward with their views. I am not suggesting that communi ty groups sho u ld not be form ed or lack legitimacy, nor that the Minister's approach is right or wro ng. Bue I am suggesting that we as

practitioners or initiators of co nsultative approaches need to respond to che changes in our enviro nment as much as any other industry.

Common-Sense Ground Rules T here are a nu mber of ground rules that need co be adhered to befo re any process will work: 1. Consultation does not mean consensus In fact, 'consult' is defined by the Macquarie Dictionary as ' to seek counsel from; ask advice of; ro refer co for information; co have regard for (a person's interest, convenience etc.) in making plans'. Th e very act of co nsultation is to gather views, preferably identifying all views, on a particular issue and to co nsider chem in the process of decision-making, planni ng or building. T hese can then go into che mix of all other information - technical, policy, legislative - when decisions are made.

is a short ti me frame, make chat clear from ch~ beginning. Explain how the process will work, what information you can provide and how feedback will be used. W hatever you do, do not lie or mislead - believe me, they will always find out in che end if you do! 4 . Consultation is not necessarily deliberation As we have seen, consultation is to seek views on an issue and to rake account of those views when making a decision of some kind. Deliberation is the ace of consideration and reflection. There is a growing movement to encourage processes that emphasise deliberation over consultation , and I will discuss these in derail later. Interestingly, deliberation in chis context seeks to move the onus of consideration from che proponent to the community ch rough the process. T he result should be more considered and studied responses from affected communities to proposals and ISS Ue S.

2. Consultation and involvement depend on trust Integri ty, honesty, respect, courtesy th ese are the foun dations of any valuable transaction between people. Consul tation is no different. Explain the process, the restraints and the objectives. T reat people with respect and courtesy. Tf these elements are reflected in all docum entation , meetings and che behaviour of th e consultation team , then people will feel comfortable in sharing their vi ews. 3. Say it as it is Don't beat around the bush, don 't overload peopl e with technical information and don 't shrink from the realities. If there

1:/,; t@:1

Choosing Your Methodology T here are a few consul tation ' favourites' that have become accepted as the best methods of co nsulting broad ly. They incl ude newsletters, face sheets, displays, meetings and workshops. A reply-paid postal address and 1800 no- cost phone li ne are also standard. Increasingly, however, we hear che complaint chat consultative acti vities are not reaching the 'silent majori ry' . There are a number of ways to address chis: Web based information Using the internet is a cost-effecrive and efficient way in which to reach a wide group of people.

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Doorknocking and street surveys Conducted well, old fashioned door k nocking can reach o ut to chose who haven 't participated in a process and really identi fy what local people chink about an issue.

Community-based events Use existing events to spread your message or create a community-based event of your own , providing a fu nd-raising opportunity for local charities and schools at the sam e rime. Local events attract local people and if you are creative you can really d esign some interesting activities for a range of age groups and demographics .

Interactive surveys using terminals in shopping centres, train stations etc Compu ter terminals established in key community gathering points allow people to q uickly and easily find out about the issu es and register a response. Such terminals can be an added featu re for d isplays.

The role for Community Liaison Groups (CLGs), workshops and meetings. As with all aspects of a consultation process, it needs to be clear what the

purpose of rhe activity is and the boundaries around how it is going to operate. Developing a ch arter with a Community Liaison Group allows all parties to abide by and respect certain rules. I r can also provide clarity about the influence the group is able to have over the project . If a CLG is form ed during the construction stage, w hen d esign is largely complete, then there is licrle point in d iscussing design in any ocher conrext than how construction is going co affect residents. If, however, the fina l siting and aesthetics are not decided , chen ic is appropriate chat chose people m ost affected by the p roject have a say in what a new structure in their neighbourhood will look like and where ic wi ll go. All meetings and workshops need to be faci litated appropriately. This does not necessarily mean forma lly, as too fo rmal a process can stifle d ebate and be intimidat ing. Bue ic does m ean chat the purpose needs to be clear and there is recognition of che two-way communication flow - meetings are fo r gath ering as well as giving inform ation. Expectatio ns chat 'communities be advocates' are nor app ropriate, for example.

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Alternative Methods for Representative Consultation There are cwo m ajor alternative methodologies char have been trialled in Australia bur not necessarily capitalised o n. These are particularly useful for: • Contentious p rojects where rhe 'public good' needs to over-ride individual aspirations; • Scare-wide and national issues; and • High-level or srraregic policy and planning issu es, which are hard for many people to fully understand in the necessarily abbreviated form of a public consulrarion process. Each of these methods demands rigour in planning and execution in ord er for them to be effective and are necessarily resource intensive. H owever, they offer the legitimacy and authority often lacking in more basic co nsultation programs. Boch methods rely on random selection through a transparent and accountable process.

Deliberative polling and televoting Using a statistically signi fica nt number of participants randomly selected , deliberative polling aims to rake participants th rough an informed and deliberative process on an issue. Preced ed by a poll and culm inating in a vo te or votes, rhe agenda is flexible, and d ebate and d iscussion are promoted. D eliberat ive polling and celevoring are useful tools when deliberation on a complex issue is required. Televoring uses less resources and is therefore less expensive than d eliberative polling, however ir is also less deliberative. Both rely on infor mation being provided to participants and their engaging in discussion based on char information, either with each ocher or with fami lies and friends during a televore.

Citizens' Jury Like rhe previous two approach es, Citizens' Juries are highly form alised processes relying on the integri ty of the process for their authority. A randomly selected panel is brought together to deliberate on an issue in an incense process over a number of days. Participants are selected so that together they refl ect rhe d em ographics of the wider group th ey are representi ng, for example rhe local government area or state. Information in the form o f p resentations by witnesses is provid ed and participants, guided by a faci li tator, can interrogate chem. The level of information and del iberation is rhe highest of all consultative methods, due to the small size of rhe jury (usually between 12 and 25) and the incense nature of the process. T he process is defined by rime and participants are prepared before and during


the process for the process of framin g recommendations. T hese methods provide an alternative way co gather views and the opportunity co ensure chat deliberation is based on a balanced body of knowledge. Accountability and the rigour of the processes extend beyond random selection. A well -run process has involvement from all sectors on an issue, with a collabo rative approach and support for all information being available for participants co consider. The quire remarkable outcome of these processes, and what makes chem so exciting and so auchoricacive, is che way in which individuals move from deliberation on their own behalf - as evidenced by their responses to pre-polling prior to their participation - cowards deliberation on behalf of the 'greater good'. Whether it is because of our inherent sense of justice, or our long-standing commitment co democracy, or just because we are who we are, all these processes produce an outcome char is based on decision making on behalf of che con stituents, nor on the individual.

Conclusions In chis article, I have largely focussed on methodologies and coo ls, as I know char man y people seek new ideas on these issues. However, I would li ke co stress chat che much vaunted 'consultation burnout' phenomena is not one I have encountered when working with people who have positive experiences of consulrarion. I suspect char much of che root cau se of 'consul cacion burnout' is rhe demoralisation chat follows when much effort for little effect has been expended. We live in a d emocracy wich a popu larly elected governm ent governing on our behalf. Government very often makes decisio ns chat are necessary - not necessarily right, but necessary. At che end of the day, chat is government's job. Letting the community know char a decis ion is made, particularly one chat is not palatable, is not che most pleasant of casks, but ic is important char co n sulcation is not used as a softening device for bad news. All of us wane respect and cou rtesy in our dealings with each ocher. Let 's consul t when we know we can cake accou nt of che views being offered. Lee's cell the community how it is when we can't. And lee's nor confuse che two.

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DECEMBER 2004 75


KWINANA FREEWAY BUS TRANSITWAY STORMWATER PROJECT I Hart, K Zic Figure 1 presen ts an aerial photograph of the site and sho reline of the Swa n River where the treatment systems were installed .

Abstract This paper presents a practical application of water-sensitive design concep ts and addresses the hydraulic features of a stormwater treatmen t system wh ich combines a prop rietary solids removal device and an o il separation chamber. N ineteen system s were installed along a freeway in Perch and h ave operated successfully over the past three winters.

The treatment systems consist of a u nique combination of scormwater treatment unit and oil separatio n tank. T he concept itself is relatively new and the level of the interaction between the t reatment units and sep aratio n tan ks was an unknown quantity. The treatment system layouts were individually designed for each of the 19 outfa lls co make optimum use of the existing outfalls and keep the extent of the construction wo rks co a mini mum. T his reduced the impact of the works on the sensitive fores hore and river areas .

Introduction

The Kwinana Freeway Bus Transitway project required the design and construction of 4 .9 km of a twolan e bus transitway down the middle of the existing six-lane Kwinana Freeway from the Judd Street interchange co This paper p resents a practical Manning Road in Perch, Western application of water-sen sitive design Australia. H WE-Clough, a joint co ncepts and specifically add resses venture between Henry Walker El tin hydraulic fea tures of the scormwater Figure 1. Aerial photograph of a section of the and C lough Engineering was the system as well as the design details Kwinana Freeway Bus Transitway along the contractor, while Kellogg Brown & employed co en sure thei r successful shoreline of the Swan River. Root (KBR) was the designer fo r the implemen tation . joint venture. The major components of the bus rransitway p roject, however, 19 Treatment system of th e work were the construction of a scormwater treatm ent system s were dedicated public transport corridor down General constructed at existing major outfalls along the centre of the freeway, foo tbridges, a bus T h e new drainage system was designed co the length of the ro ute. T hese systems treat bridge and a passenger transfer station. The cater fo r runoff fro m the transitway as well as the runoff generated from the freeway as project site was bounded o n the west by the the freeway. T he runoff is directed through well as from upstrea m urban catchments. Swan River and on the east by Melville Parade, in what is a highly sensirive area from both an environmental and a !FREEWAY! community point of view. The section of the Kwinana Freeway incl uded in the DOWNSTREAM .,. project is flat and low-lying with DEFENDER UNIT longitudinal gradients of less than 0.3%. - OIL STORAGE

. . .. .

A practical application of water-sensitive design protecting an ecologically important receiving water.

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WIER MANHOLL -1.i---EXIST ING STO ~MW~TER Pl,PE EXISTING OUT! ALL STRUCTURE . -- -- -..,.,:z1-++tf-l--in,,-_- _- _--=EXISTING FREEWA Y OUTFALL 1~ -

STRUCTURE . Working within the narrow and restricted site required many innovative design and construction techniques . H iscorically, all freeway d rainage discharged directly into the Swan River and was untreated. As part

76 DECEMBER 2004

water

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Figure 2. General arrangement of the treatment system.


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projects rhe scormwarer treatment systems before entering the Swan River via the original outfalls. The design criteria for the performance of rhe treatment system can be summarised as follows. I r must be capable of: • creating 90% of rhe coral volume of runoff throughout rhe year (equal co a 1-in-3-month rainfall event); • operating under a range of tidal conditions; • intercepting and scoring up co 30 m 3 of oil spillages;

_l_Head difference / 1-..M,..- - -. . U . - - -

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Offtake pipes outlets

Treatment system inlet pipe

Figure 3. Treatment system - normal operating conditions.

Submerged weir

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• being bypassed in more extreme rainfall events chan Offtake ~pes the 1-in-3-month event. Treatment system inlet pipe Several design alternatives were investigated for the treatment system, following Figure 4. Treatment system - bypass case. an extensive review of world's best practice. The • The system was designed to operate design adopted consisted of: under a full range of normal Swan River • a weir manhole or chamber tidal condi tions. • a Rocla® Downstream Defender™ unit • T he system has a narrow 'footprint' • a baffled oil storage rank capable of firr ing between the freeway

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• an offrake and outlet pipe.

reserve and river foreshore which in some cases is no more rhen 4 m wide. • The modular design provided considerable flexibility during constructio n. In some cases, for example, the oil sto rage rank was skewed relative co rhe Downstream Defender unit to avoid u tility services.

All of che units had to be retrofitted to rhe existing ou tfall scruccures. Figure 2 shows rhe selected general arrangement for the system. T he overall feacures of che system and of rhe individual elements are described below. Features of the system

T his arrangement was selected for the following reasons: • T he operating characteristics of boch che Downstream Defender and the baffled oil storage were supported by both experimental and field data. • The system was designed as an offline system, which means chat in more extreme rainfall events i r can be fully bypassed; chis mi nimises the release of collected sediment, fl oarables and oil back into the environment. As an offline system ic creates only a minimal impact on the hydraulic efficiency of the upstream pipe network system servicing the freeway.

All system components were p recasr excep t in the case where a masonry weir chamber rather than a precasr weir manhole was used. This meant the construction period was reduced co approximately rwo weeks in coral for each system and therefore dewarering requirements were minimised. Weir manhole/chamber

The piped network system servicing rhe freeway discharged directly into a weir manhole/chamber which diverts rhe flow co the treatment system under normal operating flow races and tidal co nditions. Figure 3 shows rhe operation of che weir manhole under normal operating conditions.

Table 1. Treatment capacity in terms of flow rate.

Downstream Defender unit[mm]

Flow rate (L/s) Tide level 0.48 m AHD Lower limit

Flow rate (L/ s) Tide level 0. 11 m AHD Upper limit

1800 2400

55

l l2

90

3000

130

183 260

78 DECEMBER 2004

water

During more extreme events, che hyd raulic loss through the system increases, resulting in the weir being overro pped and rhe rrearmenc system being bypassed. In chis case the weir becomes su bmerged, with minimal head berween the inlet and ou tier pipes, and therefore affects the flow our of the treatment system . This limits rhe release of sediment, floarables and o il collected within the treatment system. The schematic of rhe bypass condition case is shown in Figure 4.

A masonry weir chamber rather than a precasc manhole outlets was used to accommodate multiple-entry pipes. T his was required in cases where the City of South Perth's sro rmwacer pipes were adjacent co chose servicing the freeway. T he flexibility provided by using a masonry chamber also meant rhac the length of the weir could be selected to suit the fl ow rares and losses with in rhe upstream pipe network system during more extreme bypass events such as a 1- in-5-year even t. The system was also checked for a 1in- l 00-year event. The Downstream Defender

Srormwarer is d ischarged from the weir manhole co che Downstream Defender unit, which in this ap plication ranged in diameter from 1800 mm to 3000 mm. Figure 5 shows a schematic of the unit, consisting of a concrete cylindrical vessel with a sloping base and internal components. Ac the Downstream Defender u nit, solids , grit, sand and silt are removed; floarabl es are retained; and oils and grease are intercepted. Raw liquid is introduced tangentially into che side of the cylinder and spirals down che perimeter, allowing heavier particles co seccle our under gravity and che d rag forces on the wall and base of the vessel. As che flow rotates about rhe vertical axis, solids are d irected cowards the base of the vessel where they are scored in the collection facility. The internal components direct the main fl ow away from the perimeter and back up the middle of the vessel as a narrower spiralling column rotating at slower velocity than the outer d ownward flow (source: Roda's technical summary on rhe D ownstream Defender - see Reference). The sizing of the Downstream Defender units was based on: • the l-in-3-monch storm event (it treats more than 90 % of coral annual flow);


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Figure 5. Schematic of the Downstream Defender unit (courtesy of Rocio) .

• rhe assess ment of hydraulic losses ch rough che treacmenc syscem. T he Downscream Defender unit inlet pipe sizes used in this applicacion were increased by one size (i.e. from 300 111111 to 375 111111 in diameter) over che sizes specified in che manufacturer's recommendations. T his modifica cion was mad e to reduce the local entry losses and frictional losses within the system. Based on ex perimental data the manufacturer confirmed char this was acceptable. Oil separator/storage tank

F rom the Downstrea m Defender unic the sto rmwacer is discharged into an oil separato r/storage rank. T he des ign of the tank was based on the fi nd ings reported by Hen ry et al. (1999) . Figure 6 shows a sectional view of the oil separator/storage tank. The features of the tank ca n be summarised as fo llows: • T he invert and obvert levels of the tank ensure char a free surface exists even under high -ride conditio ns. • T he inlet pi pe is set at the top of the rank. Flows are then forced downward by a baffl e with an opening locaced 500 mm from the invert of the rank. The baffle is used to prevent incoming stormwarer disturbing and mixing with previously captured oil in the main storage chamber. • T h e sizing of che rank allows for 30 m3 of storage above the flow zone. • T he inlet pipe and offcake outlet pipe are located ac opposite ends of the tank to

Figure 7. Existing pillbox outfall and lowflow pipe.

Brown & Root) has tkvdopl'd

Figure 6. Oil storage tank section.

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increase the detention rime th rough the system. • The offtake outler pipe is sec lower than the opening through the upstream baffl e, fo rcing a slight downward direction in the flow and promoting oil separation. T he offrake outlet pipe discharges back into the weir manhole on rhe downstream side of the weir. The invert level of the offtake outlet pipe is set below the high-ride level. So me exchange of water within the storage ta nk would therefo re occur daily, hel ping to minimise the stagnati on of stormwarer in the rank over the summer period.

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Outfall modifications T he treated srormwarer is eventually discharged from the downstream side of the weir manhole/chamber through co rhe existing outfall structures ro the ri ver. T hese outfalls are of a pillbox-type construction as shown in Figure 7. O ptimum use of the original pipework and outfall structu res was made co ensure no new outfalls would be required. Al l outfalls which were co nnected to treatment systems had 600-mm-diamecer low-flow outlet pipes inco rporated. The orienracion of the outlet pipe was set at the front of the outlet structure to mi nimise rhe flow path co rhe ri ver and thus the potential fo r beach erosion. T he outlet pipe, however, does provide an opportunity fo r the sand to be flushed. Ir should be noted that th e modifi cations proposed are similar to so me of rhe existing C ity of South Perth outfalls which were observed to operate sarisfacrorily. O ther pillbox outfalls without the low-flow pipe were observed to be heavily blocked with sand, grit and sea weed all year round. Scone pitching was inco rporated to manage and confine the erosion of the beach when chis occurs. Ir was also recommended char modified outfalls be maintained annually prior to winter to remove any accumulated sand. Maintenance notes fo r this were

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DECEMBER 2004 79


projects incorporated on rhe design drawings. The type of machinery required fo r this maintenance work is consistent with that required to main tain the Downstream Defend er units.

Treatment System Sizing And Efficiency Table 1 presents rhe lower and upper flow rares able to be treated before bypassing of the system (overtopping of rhe weir) occurs for differe nt Downstream D efender unit sizes. Individual treatment systems were sized by marching che flow rate for the l-in-3-monch storm event, determined by hydrologic modelling of rhe contributing catchments, with chose given in Table 1 fo r the lower-limit case. The water level of 0. 48 m AHD represents the lower-limit case in terms of flow able to be treated (i .e. rhe least head available to d rive the system). This water level equates to the annual high ride for the year 2000 at Barrack Street J ecry which is in the vicinity of the project and has a 3% probability of being exceeded. This level is only slighcly lower than the Highest Astronomical Tide (HAT) of0.52 mAHD. The tidal level of 0. 11 m AH D represents the upper-limit case, wi th rhis level corresponding to the invert level of the offtake ouclec pipe as it enters the downstream side of the weir manhole. Based on the manufacturer's data for the flows presented in Table 1, rhe scormwarer treatment system is expected to remove sedimen t particle sizes above 50 Âľm (50 microns). The monitoring results of si milar o il separator/storage tanks show oil and grease removal effi ciencies ranging between 40% and 50% under normal operating conditions (Henry et aL, 1999). Those systems were in-line systems and therefore rhe removal efficiency of the proposed offline stormwarer treatment system is expected to be greater as flus hing of captured oil within the rank would be prevented. During a spill event the oil removal efficiency is exp ected to be significancly greater than 40 % to 50 % as a consequence of the larger oil droplet sizes.

Acknowledgments

The Authors Ian Hart was a member of rhe KBR ream on ch is project, bur now works for Fremanrle Ports; his email address is iharc@freman rleporrs.com.au. Dr Kresho Zic is still with KBR; his email address is kresho.zic@halliburton.com

T he authors acknowledge the work of their colleagues from rhe design and construction ream which ensured the successful implementation of the design o utlined in this paper. In particular, rhey thank Peng Saw and Craig Ramm (KBR) for their contributions to rhe design of rhe overall drainage system .

References

Their thanks go also to Roda fo r permitting rhe use of irs tech nical informat ion in this paper and in particular to Paul Cammans fo r his input in the design and installation of rhe u ni ts.

Henry D, Liang Wand Ristic S (1999) Comparison ofyear-round pe1farmance for two types ofoil and grit sepamtors, M inist ry of the Environment, Toronto, Ontario. Roda Pry Limited (2004), Downstream Defender: oil & sediment separator (Internet).

Summary The paper presents a p ractical application of water-sensitive design fo r the treatment o f freeway stormwarer runoff. T he construction of the entire Kwinana Freeway Bus T ransirway project was completed in 2002, while stormwarer treatment systems were completed in 2001. Figures 8 and 9 show elements of the treatment unit during the construction. Sire inspections have confirmed that the systems have operated effi ciently for rhe past three years .

80 DECEMBER 2004

water

Figure 9. Treatment unit dur ing the installation, looking from the downstream end of the oil storage tank.

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Water Journal December 2004  

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