Water Journal March 2002

CONTENTS 4

FROM THE FEDERAL PRESIDENT: Keeping the Community in the Loop

6

FROM THE EXECUTIVE DIRECTOR: Water Resources in Australia's North

8

INTERNATIONAL AFFILIATES: WEF Report

9

MY POINT OF VIEW: Victoria's Vision for Sustainable Development

10

CROSSCURRENT: Water News Around the Nation

FEATURE: SHOWCASE OF AUSTRALIAN INNOVATION INNOVATION: WATER 18

JAMESON CELL INDUCED AIR FLOTATION From the mineral industry to water treatment: Flotation by a simple plunging jet B Atkinson, C Con way

Jam eson Ce ll - Page 18

THE WORLD'S LARGEST IMMERSED MEMBRANE PLANT Memcor has developed hollow-fibre microfilters suitable for gravity operation

24

K Craig, B Bowen , R Naylor, W J ohnson

28

AQUIFER STORAGE AND RECOVERY IN SOUTH AUSTRALIA Low quality waters can be successfully stored and recovered underground

32

DESTRATIFYING DAM PROBLEMS Destratification by mechanical means is more effective and cheaper than bubbling compressed air

34

DEALING WITH MANGANESE SLUDGES Preventing build-up of manganese justified million-dollar pipelines to transfer WTP sludge to distant sewers

R Martin, P Dillon

S L Ellio tt, P Morga n

G Hamil ton

36

GENETIC ALGORITHM OPTIMIZATION APPLIED TO WATER DISTRIBUTION SYSTEMS Cheaper networks designed by novel computer software

42

MIEX® - GOOD RESEARCH COMMERCIALISED Australian-invented magnetic ion exchange resins adsorb troublesome organics prior to alum treatment. The first full-scale plant is now commissioned

Miagnetic ion exchange - Page 42

P Ra dcliffe

M Slunj ski, H Nguyen , M Ballard, R Eldrid ge, J Morran , M Dri kas, B O'Lea ry, P Smith

INNOVATION: WASTEWATER 54

CONVERTING SEWAGE SLUDGE TO FUEL OIL The first full-scale plant in the world is now operating in Perth, with a net energy output T Bridle, T Casey, M Domurad

60

IMPROVING THE EFFICIENCY OF STPs Dosing an activated sludge plant with a specially prepared mineral possessing ion exchange and adsorptive properties yields a wide range of benefits

Improving STP performance - Page 60

L Ch aruckyj

64

THE CDS STORY: CONTINUOUS INNOVATION Deflective screening is non-blocking. First developed for litter traps, now suitable for combined sewer overflows, and even for physico-chemical clarification of raw sewage RA J ago, A Davey

70

THE AQUABLADE DIFFUSER Development of every engineering and chemical detail has yielded a revolutionary fine-bubble air diffuser G J ohn ston , P Fullwood

• envzro sensors

with Dr Lange Nitratax Plus Photometer • • • • 2

No ultrafiltration or sample preparation Direct immersion in medium/activated sludge No calibration /self cleaning Installations Australia-wide WATER MARCH 2002

72

BENEFICIAL REUSE IN ACTION Vermiculture, properly engineered ond quality controlled, transforms sludge into a premium product for horticulture, commanding profitable prices J McCarthy

78

MELBOURNE'S WESTERN TREATMENT PLANT SOO ML/ d of domestic and industrial sewage is treated mainly by huge lagoons. Arecent hybrid

process produces both water suitable for re-use and reduces nitrogen discharge to Port Phillip Bay B McLean, P Scott

84

TREATING ARSENIC MINE WATER USING A HYBRID MEMBRANE PLANT Aprocess chain which successfully treats highly polluted mine waters to receiving water quality

88

COCOS (KEELING) ISLANDS WASTEWATER TREATMENT PLANTS Apatented aerator and decanter ensure stable operation of an IDEA plant on a tropical island

P Macin tosh

Worms process biosludge - Page 72

C Shinton

91

IMPROVING THE ENVIRONMENT NATURALLY The largest reed bed system in Australia is based on the CSIRO underflow system J Wilkinson

INNOVATION: ENVIRONMENT 93

DYRESM Professor lmberger' s team at the University of Western Australia is the world leader for modelling lake dynamics J Antenucci, D Horn

97

INSTITUTE FOR SUSTAINABLE FUTURES The University of Technology, Sydney, assists stakeholders in least-cost planning and end-use analysis MJ h a

99

MANAGING MANLY BEACH FROM SOURCE TO SEA

Reed bed system - Page 91

Astormwater treatment and re-use project incorporates innovative technology B McRa e

I 02

HYDRO-ACTIVE LIMESTONE TREATMENT (HALT) SYSTEM Alow-cost system for neutralising large flows of acid mine waters and sulfate soil drainage J Ta ylor

INNOVATION: BUSINESS 104

THE NATIONAL WATER QUALITY MANAGEMENT STRATEGY Sumarising the policies, processes and risk-based guidelines adopted by Australian States to enhance the quality of water resources: both environmental and drinking water M Marti n, C Lewis, N Hardy, P Callan

106

REFORMING AUSTRALIA'S WATER INDUSTRY The National Competition Policy has extended to the water industry, and has led the path to reform: clarification of roles, better water pricing, allocations to the environment, irrigation water trading G Sam uel

I 08

A REVOLUTION IN PVC PRESSURE PIPE An Australian company has developed an in-line process for manufacture of stronger PVC-0 pipe

110

A SIMPLE AND COST-EFFECTIVE SPILLWAY DESIGN/REVIEW TOOL FOR FARM DAM

Innovation in stormwater - Page 99 Ill;.i,,o,..,,...

_ _ .,

- ... 1.... - 1-

1- 1 -1-

_ _ _ _ _ _,,, 1' - 1 - 1 - 1

P Chrys tie

OWNERS Asimple cost-effective package for flood capability and spill-way design for farm dams reduces the risk of catastrophic failure J D Pisaniel-Jo, J M McKay

114

ASSET MANAGEMENT OF SYDNEY WATER'S SEWERAGE SYSTEMS Sydney will be spending some $2 billion on sewer overflow abatement. OACIS software underpins the asset management plan, and was developed collaboratively by client and consultant I Garside, S Hall

117

Asset management - Page 114

LIFE CYCLE ASSESSMENT IN A MAJOR WATER AUTHORITY Sydney Water employs many planning and reporting tools, but LCA is essential for proper comparison of options to attain sustainability G Peters

119

DERCETO: AN ONLINE PUMP SCHEDULE OPTIMISATION SYSTEM This software schedules pumping/ storage to take advantage of off-peak power and least-cost water sources J Wardle, S Bunn

RESEARCH 121

COOPERATIVE RESEARCH CENTRES: THE WATER FORUM The Australian Cooperative Research Centres Progrqm has been immensely successful in linking research to stakeholders. Five CRCs deal with water: Catchment Hydrology, Coastal Zone, Freshwater, Waste Management and Water Quality WATER MARCH 2002

3

INNOVATION:

WATER

JAMESON CELL INDUCED AIR FLOTATION B Atkinson, C Conway j et. T he inetic energy of the j e t res ult s in air b ein g entrained into the downcomer in much the sam e way as air 4 - - lntroduce Air might be entrai ned into a I ntroduce Polymer _ _...,-flr\tl bucket of wate r using a hose.

Background Downcom er Air is dragged down into the The J am eson Cell indu ced liquid and the turbulen ce air flotation (IAF) device was created aro und the recycle jet Hydraul ic seal dow oc:omcr · invented by Professor Graeme dissipation area breaks up th e Jameson of the Unive rsity of air film into small bubbles of SL UDGE Newcastle, NSW, Australia in m ean size 300 microns. The the late 1980s. T he Cell, Jam eson Cell thereby utilises w hich is patented by The Slud1e Collection the energy of the fluid to Uni ve rsity of Newcas tl e TRl!ATB D induce air into the cell, rather WATBI R esearc h Assoc i ates than requi ring an external (TUNRA) Limit ed, was compressor or blower. The initially developed for the bubble size ranges from below coal and mineral industries, 50 micro n up to 1 mm .

Figure 1. Jameson ce ll schematic and the licensing rights were The presence of air bubbles acquired by MIM Holdings at the tirhe of flo cculation is liquid wastewater streams. In the flotation Limited, Brisbane, Australia. MIM has a extremely b en eficial as it results in the process, fin ely dispersed air bubbles are wo rld-w ide exclusive license fo r the bubbles being entrapp ed w ithin the brou ght into contact with the chemically technology for all m etallurgical applicaactual flo e structure. T he incorporation of conditioned slurry and particle-bubble tions, and the Jameson Cell has been bubbles in the flo e stru cture provides attachment occurs. The particle-laden install ed in numerous m ajo r minerals & buoyancy and allows particles to be floated bubbles float to the surface w here they are coal proj ects on the wo rld-w ide market. independent of their surface characteristics. removed from the cleaned was tewater.

While MIM enjoyed significant success in The do w nwa rd velo city of th e In the Jameson Cell (Figure 1), a "low the mineral industry, Professor J am eson shear" m ethod is used to mix the air, bubble/ liquid mixture in the downcomer and fellow development staff pursued untreated was tewater and flo cculants. is chosen such that all bubbles have to alternative applications for the technology.

The untreated was te·water and flocculants descend and em erge into a reservoir (or Initially, such applications were in the area are introduced into the top of the cell) at the bottom of the do wncomer. of industrial effluent treatment, particudow ncomer at low head. A portion of the T he reservoir acts as a disengagement zo ne larl y for th e dairy and indu strial clean efiluent is recycled back into the top allow ing the aerated flo e stru ctures to m anufacturing applications. It was soon of the downcomer. The recycle stream 'float' to the surface to form a sludge layer. appare nt that the J am eson Cell IAF passes through an orifice, accelerating the T he sludge overflows th e reservoir into .process was excellent for the removal of liquid to produce a simple liquid plunging a launder w hilst the cleaned efilu ent passes suspended solids, oil and grease from to the next stage in the pro cess . Sludge eillu ent streams. A couple of demonremo val is fac ilitated using either a stration sites we re installed during 1993-4 rotating paddle or chain & flight scraper and follo wing th eir success, J etflote was arrangement. granted the license for the Jam eson Cell for non-metallurgical applications and The Jameson Cell has the fo llowing commenced trading in July 1994. advantages over conve ntional flotation technologies : Environmental Group Limited (EGL) acquired th e business of J etflo te Pty Ltd • the cell has minimal moving parts and in September 19 99, including the therefore requires a minimum of mainteexclu sive wo rld-wide li ce nse of the nance Jameson Cell technology for wa ter appli• no compressor is requi ted cations. EGL is an Australian-owned • T he process is inherently a low power public company listed on the Australian consumer. The air is self induced as a result Stock Exchange . of the action of the plunging j et in the Technology description vertical downcomer. Pro cess power is typically less than 0.1 kWh per cubi c Flotation is an extremely effective Figure 2. Jameson Cell insta ll ation at metre of wa ter trea ted m eans of removing fine particles from Mil burn Park Wines, lrymple, Victoria.

A unique method for operating flotation in the mineral industry has now been applied with great success to wastewater treatment.

18

WATER MARCH 2002

Introduce Raw Feed

The "Jameson" Flotation Cell

INNOVATION:

WATER

tional clarification. T he process is equally effec ti ve for sl ud ges ge n e rated from ae robi c and anaerobic treatment, and is particularly useful for "bulking" biomass that typi cally won' t settle in a clarifier.

Algae: A major problem with many inland wastewater treatment plants is th e ptoliferation ofblueg r e e n a nd gre e n al g ae in wastewa ter stabilisation ponds.

T he generation of algae in ponds often results in EPA li cense Industrial Effluent Applications excee dances du e to elevated Figure 3.Tertiary treatment - Wagga Wagga Narru ng St The Jameson Cell technology suspended solids and pH levels.

STP is w idely installed as a primary D espite this problem , ponds have trea tment system for th e rem oval A recent application of the Jameson a numb er of important advantages w hich of suspended solids, oil and grease. As a Cell has been for the rem oval of filter include providing treatment for we t general rule, the IAF process w ill remove media (eg. diatomaceous earth) from highwea the r byp asses of th e sec ondary 95-99% of the insoluble components. strength w inery effiu ents. process and as an important treatment Flotation cannot remove the solubl e backup in the event of upstream process Wastewater treatment components of contam.inants unl ess they fa ilure.

Biomass : The IAF process has also can be easily precipitated (eg. phosphorus) .

A R esearch Syndicate was established been fo und to be extrem ely effective for The process is particularly suited to in 1995 and Jetflote condu cted extensive biomass separation fo llowing seconda ry removing emulsified fat, oil and grease in r ese ar c h on d eve l opin g fl o tation treatment. Th e main advantages are the additio n to the BOD / C OD associated technology to remove algae from affected low footprint and high sludge solids wi th the emulsion and the susp ended w astewa ter streams. ':J;'he first stage of the content (4% to 8%) compared to conve nsolids.

• the low residence time of the cell makes it simple to operate and control • compact design (total footprint based on rise rate greater than 18 m 3 / m 2 .h) • the cell is capable of op erating at temperatures of up to 70°C as compared to a process relying on dissolved air whic h is typically ineffecti ve above 45 °C du e to reduced solubility of the air in the was tewater.

Pipe Lining & Coating

I

PTY Limited

Specialist Manufacturer and Supplier of Fabricated Steel Cement Lined (MSCLJ, Epoxy Lined, and Coated Pipes, Fittings and Custom Des· ed Pri

WATER MARC H 2002

19

INNOVATION

project involved culturing of Microcystis sp and Anabaena sp. and undertaking laboratory testing to develop appropriate mechanisms for flotation of the algae. This involved developing an understanding of the surface chemistry of algae The next stage involved construction of an IAF pilot plant to further develop chemical regimes and the optimum configuration for operation of the IAF unit. The pilot plant was extensively evaluated on-site on several algae-laden pond storages .

The proving of this technology was the culmination of three years of research and on-site trialing in the Hunter Valley and other inland sites in Australia. T he pro cess has been proven for raw w ater algae levels exceeding one million cells per mL of algae (corresponding to raw w ater suspended solids levels of the order 150200 mg/ L). Treated water algae levels h ave be e n ge n e ra lly b elo w 5 ,000 cells/ mL. Phosphorus: The IAF process can be combined with conve ntional m etal salt precipitation/ coagulation of solubl e phosphorus is order to simultaneo usly remove algae and phosphoru s from wastewater effiu ents Ve1y low levels of residual phosphorus can be achieved by sin gle -point c oag ul ant do sing o f aluminium sulphate (alum) or ferri c chloride. eg. total phosphorus less than 0.2mg/ L can be achieved from ra w w ater ortho- P levels in excess of 8 m g/ L. The J ameson Cell IAF technology provides a cost effe ctive alternative to upgrading inland wastewater treatment w orks since it addresses the problem of algae grow th in ponds , th ereby allo w ing 70 w at e r a u thoriti es a nd councils to continu e to ~ 60 utilis e th e b e nefit s of §. 50 wastew ater pond systems. ~ 40 E The aim of providing an 8 30 effective m eans of simulta8 20 neous phosphorus removal is 10 also addressed .

WATER

PROVEN APPLICATIONS • • • • • • • • • • • • • • • • •

Winery effiuent Algae Dairy effl uent Abattoir General manufacturing Commercial catering Sugar milling and refining Wool scouring Vegetable oils / margarine production Paint manufacture Paper processing Phosphorus Smallgoods and grocery item manufacture Compressed wood products Piggery effiuent - primary treatment Oil production and refining facilities Tank & truck was hin g fac ilities

discharge to sensitive receiving wa ters.

Process plants have since been installed for W agga W agga C ity Council (Kooringal 5 M L/ d) and N orth East R egion Water Authority (NERWA) (Wangaratta North, 6.5 M L/d).

Export

Jam eson Cells are installed in Korea and M alaysia for efflu ent trea tment from compressed timber products manu fac ture and terminal tank washing fac ilities . In UK the technology is represented by Brightwater Engineering.

C

Installations

The first municipal unit to remov e a l ga e a nd phosphorus from treated sewage (maturation pond) effiu ent w as installed for W agga W agga C ity Council at their Narrung Stree t Sewage Treatment Plant.

T he plant, capable of treating up to 18ML/ d, was commissioned in Ju ne 1999, and has met or exceeded all performance ex p ec tations, producing w ater suitable for 20

WATER MARCH 2002

Suspended Solids

Turbidity

• Bilge water treatment from commercial and naval vessels • Treatment of coolin g waters 111 aluminium casting • Baking, milling and yeast operations • Separation of c uttin g oils and emulsifi ed oils from engin eering workshops or rail washdo wn facilities • Particulate removal from coal stockpile run-off for water reuse • Shampoo and hai r care products manufacture • Prima1y sewage • Stormwater / Comb in ed Sewer Stormwater overflows .

• Oil seed processing • Aerobic & ana erobic reacto r solids (biomass) separation Research and Development

There rem ain numerous application areas for w hich the Jameson C ell is likely to be a leading edge technology solu tion.

The IAF process has been demonstrated for seve ral appli ca tions in sewage trea tme nt in cluding primary solids removal, clarifier supplem entation or repla cement, biomass separation and efflu ent polishing (algae and phosphorus removal). The process is very compact and cost effi cient compared to traditional technologies, w ith a footprint based on a rise rate of 18 m/ h or more. T he process is well suited to stormwa ter a n d co mbin e d se w e r ove rflow (CSO) trea tment du e to the features of low start- up time, high process rate, and ease of augm entation to an existing site.

Total Nitrog en

Pilot-scale rigs (20 L/min) are availabl e for on-site testwork to confirm process amenability and to evaluate reagent addition requirements.

The Authors: 3.5

~

3

§. 2.5 C 0

~

2

~

1.5

8 0 .5

Ortho Phosphous

Total Phosphorus

Figure 4. Tertiary treatment - contaminant re moval at Wagga Wagga, Narrung ST STP.

Bruce Atkinson and Chris Conway are Gen eral M anager - Water Division and Principal Applications Enginee r '3/ith Env ironm ental Gro up Limited, PO Box 426 CardiffNSW 2285 Australia, Tel: 61 (0)2 4954 5889 Fax : 61 (0)2 4954 9910, e mail: m a il @ environmental.com.au, web: www.environmental. com.au

INNOVATION:

WATER

THE WORLD'S LARGEST IMMERSED MEMBRANE PLANT K Craig, B Bowen, R Naylor, W Johnson In 1998 USP Memcor, introduced its fourth generation CMF-S technology wh ic h incorporated m embrane modules in a simpler configuration · similar to conventional gravi ty filtration. Th e objective was to produce a membrane process suitable for medium to large scale applications. The n ew CMF-S imm erse d membrane technology was fully trialled, then commissioned for the 126 ML/day Sandhurst water treatment plant. This plant is the largest immersed membrane plant in the world for potable water treatment.

Introduction

T his-pap er describes the C MF- S system and the process train used for the 1 26 ML / d ay wa t e r treatment plant at Sandhurst R ese r v oir , B e ndi g o , Australia. It also discusses w ater quali ty standards and the multi-barrier approach appli e d to achi eve th e r e quir e d stand a rd s to 1111ni rn.ise public health risk and m aximi se aes th e ti c quality of this water supply.

Performance Specification The Aqua 2000 contract requires that wa ter quality and quantity to be measured at a numb er o f p o ints w ithin each of the wa ter trea tment plants and at inte1f ace points.

M embrane treatment for public w ater supply has In te rface points a re grow n exponentially since Figure 1. Aeria l View of the Sandhurst WTP under construction defined as po ints in the 1990. T he absolute barrier system w here the w ater is provid ed by m embran e treatment and the capacity tr a n sfe rr e d from t h e The Coliban "Aqua 2000" Project to d elive r consist e nt qu ality w ith tor to the C lient, and fro m the contrac The Coliban W ater " Aqu a 2000" minimum operator attention j ustified their lient's perspective, the point at w hich C Proj ect is a BOOT proj ect awa rd ed to use initially in small treatment applications. their customers rece ive the wa ter. Each Vi ve nd i W a t er for th e d es i g n , In recent yea rs microbiological standards of the interfa ce p o ints is m o nito red constru ction and 25 yea r op eration of h a ve ti g ht e n e d fo ll ow in g we ll c ontinuo usly for chlorine res idu al , th ree w ater treatment plants of capacity documented parasitic disease outbreaks. press ure, flow, pH and colo ur. D aily 7.7, 18 .4 and 126m1 / day plus reservoirs T hi s d eve l o pm e nt h as favo ur e d and reticulatio n, in the B endigo area of sarn.ples are taken for bac teriological membrane systems but until recently cost Victo ria. T he co ntrac t has ve ry stringent indicators and physicochen1..ical paramhas precluded m embrane application in wa ter qu ality targe ts that have been eters. large plants. adapted from the US and EU drin king From a w ater treatment persp ective the In 1998 M em cor Australia introwa ter standards. challenge can be summarised as fo llows : du ced its fo urth ge n eratio n C MF- S To meet th ese, high techno logy • Continuous 2 to 5 micron particle t ec hn o l ogy, d eve lop e d in th e ir p rocesses we re ad opted . Conve ntional r e m ova l and 4- l og re du c t io n fo r Technology Centre, Windsor, NSW, C MF n1..icro fi.ltrati on was chosen fo r the C ryptosporidium w hich incorporated m embrane m o dules tw o smaller plants, but for the 126 • R eliable organics removal (algal toxi ns, in a simpler configuration similar to ML/ day Sandhurst wa ter treatment plant colour and taste and o do ur compo unds) co nve nti o nal gravity filtr ati o n . Th e th e C MF -S imm erse d m e mb ra n e • N o commercial co ntrac tu al reli ef du e obj ective was to produce a m embrane technology was selected, including coaguto unforeseen changes in raw water quality process suitable fo r m edium to large scale latio n wi th buffe ring using lime and penalties for non-compliance • Significant applicatio ns. carbon dioxide, 1111crofiltration , ozonation, over a proj ect life of 25 yea rs. biologically activa ted carb on (BAC) and T he microfi ltration m embran es were fin ally disinfectio n w ith chlora n1..inatio n . developed in Australia at M emtec in the The Treatment Process T hi s plan t is t he largest immersed 1980s . The company was bo ught by T he wa ter treatment process was m embrane plant in th e world fo r potable U SFilter and subsequently Vivendi W ater wa ter treatm ent (Figure 1). adopted after detailed inves tiga tio n of in the late 1990s.

24

WATER MARCH 2002

INNOVATION:

water quality, pilot testing and contractual risk assessm ent. Th e trea tment process is detailed in Ta ble 1.

Extensive pilot studies were undertaken to set basic design parameters. After the award of the co ntrac t a m o re extensive Process Verification study was undertaken in parallel with detailed design . The Process Verificatio n Plant (PVP) was used to not only determine and refine critical process parameters but also to test a range of analytical instruments and chemicals fo r use in the full-scale plant.

T able 2 sum.m arizes the typical wa ter q uali ty profile th ro ugh the pro cess show ing that the w ater quality targets can be met by the proposed pro cess .

CMF-S Microfiltration CMF- S mi crofiltration techn ology was chosen for the 126 ML/ day Sandhurst WTP due to its ability to meet the perform an ce sta nd a rd s a n d its sup e ri o r economics ove r conve n ti o nal C MF microfiltration for this size of plant.

C M F-S capital costs are signifi cantly lower than MF. Also the operating cost is lowe r than C MF technology . Any increase in memb rane area is more than offset by the red uced p ower cost (up to 50%) due to the lower trans-m embrane pressure (TMP). C hemical consump tion is approximately the sam e. M aintenance is expected to be lower due to fewer valves and a less demandin g opera ting cycle.

WATER

The hollow fibre fil tration membrane is fa bricated into repairable sub modules .

Four sub modules are arranged into a Sub Module Clover and up to eight clovers are connected via a stainless steel manifold to a removable Module R ack. The filtrate co nnection is via the top of each subm anifold, with backwash airflow via the bottom. Mod ule racks are suspended in an open filtratio n cell . T hey are lifted directly from th e cell for servicing (Figure 2) .

Each bac k- w ashable filtration cell co ntains up to 18 module racks (576 sub modules) . Each cell has a nominal capacity of 20 M L/ day w h en filtering typical surface wa ter.

T he Sandh urst WTP has 8 x 576 submodu le cells providing a capacity of 126 M L/day.

Raw Water Th e raw wa ter supply to the plants is provided mainly from three diffe rent reservoirs. These reservoirs are located in a vas t catc hment and are linked by a channel system. In addition to sto ck and dom estic supplies, this wa ter is used for the irrigation of areas along the channel system . Additional supply of raw wa ter may be obtained from Lake Eppalo ck w hich is a reno w ned Victorian recreational reservoir.

Pre-treatment Raw wa ter is dosed w ith lim e and carb on diox id e for bu ffe rin g and

corrosion protection . T he buffered wa ter is then dosed with a poly-aluminium chloro hydrate based coagulant fo r the coagulation of colour, m etals, particle and prima1y organics removal. A short contact time is provided to allow mi cro-floe to fo rm.

Microfiltration There are tw o types of microfiltration.

Conve ntional press ure filtratio n is used at the tw o sm aller plants. At the larger plant th e newly develop ed submerged microfiltration is used du e to the redu ced capital costs associated with pro viding micro filtration at this size of plant. T he microfiltratio n , filtering to 0 .2 micro ns, provid es a phy ical barrier to coagulated impuri ties, protozoa and particles . The wa ter q uality to be ac hieved after the microfil tration incl udes ve1y tight guideli nes for tu rbidity and particle counting.

T he turbidity standard is 0.1 N T U at 95% w ith an absolute limit of 1.0 N T U. After 12 months of op eration th e particle co unt standard to b e ac hieved is 10 particles per ml (2- 5 micron range) for 95% of the time.

The m embranes' irltegrity is tested daily using a Pressure D ecay T est (PDT). Any leaks are identifi ed using a soni c analyse r and m embranes isolated or pinned and repaired . T he PDT is simple and m ore sensitive than particle coun ting and is effective in m easuring system integri ty .

Ozonation

pH / alkalinity adjustment Control of alkalinity and pH for oxidation and coagulation, reduce reticulated water 's corrosivity

Lime/ carbon dioxide

Chemical dosing and coagulation

Coagulation of colour, metals and particles

Coagulant: liquid ACH

Membrane filtration

Removal of particulates and pathogens including Cryptosporidium oocysts and Giardia cysts

Submerged micro-filtration system (CMF-S) and Continuous Microfiltration (CMF)

O zone generation eq uipment and three compartment ozone contac t tanks have been provided. Contacti ng of ozone rich air with already clean filtered wa ter in the contac t tank causes the breakdow n by oxidation of organic molecules w hich cause taste and odour problems, and of any algal toxins , and also ac ts to provide an additional disinfection barrier to pathogens such as bac teria, viruses and pro tozoa. A CFD analysis of the contacto r design was u ndertak e n to optim ise t h e baffl e arrangement and m aximise the Ct value.

Ozonation

Oxidation , disinfection , destruction of algal toxins ,

Ozone dosing and contact time

BAC Filtration

BAC filtration

Removal of taste and odour compounds , removal of alga l toxins, reduction of disinfection by-products formation, reduction of assimilable organic carbon , removal of pesticides

Biological GAC filter

Table 1. Aqua 2000 Process Summary Unit Process

Function

Nominated Agent

Fluoridation

Fluoride for dental health

Hydrofluosilicic acid

Ch loramination

Residual disinfection to ensure inactivation of micro-organisms throughout the distribution system

Ch lorine and ammonia dosing

Treated water pH adjustment

Increases pH to target range to minimise corrosion

Lime

26

WATER MARCH 2002

Biologically activated carbon filters have been constru cted to redu ce the amount of organic carbo n in th e w ater.

T his ensures very tight disinfection byproduct standards are met and provides a secondary barrier against organic contamination caused by algal toxins and taste and odo ur. By fo stering the growth of a colony of environm ental bacteria, these filters adsorb and biologically metabolise

INNOVATION:

WATER

addi tional asse ts owned and operated by Vivendi Water.

Table 2. Typ ical water quality parameters.

Raw Water

Post CMF-5

BAC Filtered

0.9 - 2.4

0.012

0.05

8000

O - 3 (onlin e)

35 - 45 (grab sample)

10 - 22

12 (at 10 mg/ LAC H)

2-3

0.060 - 0 .2

0 .03 - 0.04 (at 10 mg/ LACH)

0.04

0 .080 - 0 .1 20

<0 .05

<0 .05

0.01 - 0 .094

<0.1

<0 .1

5 .4 - 6 .2

4- 4 .5 (at 10 mg/ LACH )

2 .0 - 2.8 (50 - 60% remova l)

TTHM 1 ¡2 (ug/L)

360 2

98

23

HAA5 1 (ug/L)

120

54

30

Turbidity (NTU) Partic les (cnt/ml 2-5 micro n) Tru e Colour (HU ) Aluminium (mg/L) Iron (mg/L) Manganese (mg/L) DOC (mg/L)

<10

Bromate (ug/L) Geosmin & MIB (ng/L)

<5

10 ¡ 30

ND 3

Algal Toxins (ug/L) Note: 1 TTHM and HAAS formation using SOS method.

2 Raw water TTHM is THMFP test.

3 None Detected.

a portion of the residual organic m atter in the wa ter to inno cuo us compounds, such as carbon dioxide and water. Because the filters are ' biologically active', the process is ongoing resulting in a prolonged life for the filter, as compared to more co nventional 'ac tivated carbon' filters w hich operate in adso rption mode.

Disinfection Water from th e BAC fi ltration stage is dosed w ith chlorine and then ammonia

to pro vide a long la ting residual disinfectant and to assist with the minimisation of THM and HAAS DBP 's . THM standard for the contrac t is 0.08mg/ L and the HAAS standard is 0.06mg/ L.

Storage and Distribution T he on-site clear wate r storages vary in size from 4 ML to 42 ML. Water from the storages flows to the distribution system und er gravity via interface points either to Coliban Waters' system or to

Waste Water Handling D ue to the inclusion of both microfiltration and conventio nal coagulation processes two typ es of waste wash water are generated on site. M embrane cleaning chemicals are neu tralised and removed offs ite eith er via sew e r or tanker.

Backwash water from the membranes and BAC fi lt er s i s re -c oag ul ated a nd thickened, with the slu dge discharged to drying beds and the supernatant recycled to the head of the plant.

Conclusions In less than a decade m embrane fi ltration h as grown from a sm all community drinking wa ter solution to a serious alternative for larger populations.

T h e plants at Ben di go in Australi a provid e a co ntinuou s multi-barri e r approach to ensure turbidity and microbiological control combined with removal of organic compounds, including disinfection by-product pr~c ursors, taste and odour compounds and algal toxins.

The use of submerged membrane technology has allowed the constru ction of the world's largest microfiltration plant in Bendigo for Coliban Water to meet high water quality standards and ensure a safe, aesthetically pleasing and reliable wa ter supply.

References 1. Cra pper. J, J ohnso n. W , Ma cCormi ck. A; C MF-S Mi crofiltration Pl ant to Treat 126 ML/ day.

2. Bowen. B, aylor. R , C raig. K; Settin g and Achieving State-of-the-arc Drinking Water Quality Standards: Australi an Expe ri ences .

AW A Regional Co nference NSW 2001.

The Authors

Figure 3. M embrane modules in position

Keith Craig is the Technical Director of Vivendi Water Australia, Ben Bowen is the Senior Operations Engineer w ith Vivendi Water Australia and Rod Naylor is the C hi ef Operating Officer of Vive ndi Water Australia (Vivendi Water Australia, Level 37, 1 M acquarie Place, Sydney, Ph: 61 2 92519800 Fax: 61 2 92513944).

Warren Johnson is the Senior R&D Proj ect M anager with M em cor Australi a Pty Limited, 5 Blackman Crescent, So uth Windsor NSW 2756, Email: kcraig@vi ve ndi water.com. au WATER MARCH 2002

27

INNOVATION:

WATER

AQUIFER STORAGE AND RECOVERY IN SOUTH AUSTRALIA R Martin, P Dillon Aquifer Storage and Recovery (ASR) has been demonstrated to improve the quality and availability of water resources in South Australia by harvesting waters such as iirban stormwater runoff and treated wastewater, and injecting them into suitable aquifers fo r later recovery and use (Figure 1) . Constructed wetlands are used to detain and passively treat stormwater prior to injection.

The Gro undwater Assessm ent Gro up , no w w ithin th e So uth Au strali an D epartment for Water R esources, has carried out a number of significant inves tigations into ASR schem es using source wa ter of varying quality . In collaboration with CSIRO this wo rk is at the international leading edge in the research , design and implem entation of ASR oflow quality waters in aquifers of low and moderate transmissivity. T he awa rd of the inaugural UNESC O Great M an- M ade River Internatio nal W ater Prize recently ackno wledged this w ork.

Proj ects range from the inj ection and storage of turbid Rive r Murray wa ter in an aquifer w here native gro undwa ter salinity exceeds 40,000 m g/ L to provide purified (algal toxin free) potable town water supplies, to the inj ection of nutrient rich treated reclaimed wa ter for w inter storage and subsequ ent recovery to m eet summer irrigation dem and (Dillo n et al 1997, 1999) (Fig 2) . Such proj ects have required innovative solutions to overcome the myriad of complexities for successful implementation. The success of these trials has resulted in ASR becoming a cornersto ne in the integrated wa ter strategy fo r the augm entation and m anage m ent of

Examples of t/, ese ASR schemes will be prese nted at th e 4th fot ernational Symposi11111 011 Artificial Rec/,arge (ISAR4) to be held i11 Adelaide 22-26 September 2002, a11d the cotiference technical to11r takes in stom, water and reclaimed water ASR sites related to the UNESCO Prize. Po11d a11d 111adi il-ifiltration, bankjiltratio11 and a range of 11rban a11d arid z one water co11servation a11d treatment methods fro111 around the world will also befea tured, under the theme: Manage ment of aquifer recharge for sustai11ability . More i11for111atio 11 about th e symposi11111 ca11 be fo1111d ai: ww111. grou 11d111ater. co111. a11 / conj/ !SAR 4. /,fn, 28

WATER MARCH 2002

Aquifer Storage and Recovery (ASR) irrigation

.,

... ...

- -- -- ... ...

., .,.

--~ .,,.

._ -- .. _

groundwater level

-- - ====----=========

Figure 1. Schematic of stormwater ASR. In winter (blue arrows) stormwater runoff is harvested in a wetland then inj ected into a confined brackish aq uifer. In summer (red arrows) the water is extracted from the same we ll for irrigation .

wa ter resources in South Australia (South Australia, 2000) .

W ithin the next seven years ASR schemes currently under development or investigation within metropolitan Adelaide are proj ected to capture, store and reuse 12 million m 3/ yea r of stormwa ter o r treated reclaimed w ater, about 6% of Adelaide's current wa ter dem and .

T here are constraints such as; storage capacity of aquifers, ability to recapture the fresh wa ter inj ected into saline aquifers, geochemical interactions altering water quality, and clogging of aquifers as a result of physical blocking of pores by suspended sediments, biofilm gro w th, chemical precipitation and re-arrangement of fin e materials in aquifers. Because of the potential for rising wa ter tables and contamination problems in unconfined aquifers, generally confined aquifers, that is aquifers insulated from the surface by low permeable laye rs, are preferred for storage of inj ected wa ter.

D eep inj ection wells and filtration equipment can be relatively unobtrusive, and opportunities may exist to use existing infrastructure to distribute the captured runoff. Frac tured rock aquifers, like deep confined sedimentary aquifers, offer good sites for the inj ection of stormw ater. Several frac tured quartzite sites have been operating in SA fo r a number of years, principally using gravity recharge of sto rmwa ter. The storage capacity is relatively small and the frac ture

networks can be connected over very large distances . Consequ ently, inj ection wa ter can move ove r these distances in a ve ry sho rt time making recove ry difficult. R em ediation of contaminatio n is also difficult so the quality of wa ter inj ected into fractu red rock aquifers should be carefu lly managed. Studies of w ater quality improve m ents during aquifer storage are currently underway (Toze et al, 200 1).

Where aquife rs are fav ourable, ASR offers a potentially low-cost method of storing wa ter as an alternative to surface storage . For systems in Adelaide using sto1mwater, typical costs are A$0. 20 - 0. 50 per m 3 ( excluding costs of flo od detention storage) while systems using reclaimed water cost A$0.1 0 - 0. 30 cents per m 3 excluding costs associated w ith the wa ter reclamation plant. T hese compare w ith a current m etropolitan m ains wa ter cost of A$0. 92 cents per m 3 .

In country regions, and in arid and se mi-a rid e n vir o nme nts, ASR ca n comp ete even more fa vourably. Because of distance and demographics annualised reticulated wa ter costs in the no rthern regions and o n Eyre P eninsula va ry between A$3.50 and A$7 .20 p er m 3 .

Expansion of w ater supply capacity in these locations co uld be more economic using ASR and utilising surplus pipeline capacities in w inter.

Australian guidelines on the quali ty of sto rmwa ter and reclaimed wa ter fo r

INNOVATION

inj ection into aquifers for subsequ ent recovery and reuse, we re produced (Dillon and Pavelic, 1996) as the result of a two yea r stud y. The guideline s co ntained sp ecific reco mmendations relating to li censing, pre-trea tment, monitoring, maximum concentrations of contaminants in the inj ected water and minimum res idence time . A strong li nkage was suggested betwee n environm ental sustainability and the economic feasibility of a proposed ASR site. It was noted that operations that are only m arginally economic might be unable to m eet the required costs of monitoring and that the level of operational managem ent might be compromised. H ence ASR de ve l opments ha ve foc u sse d on commercial-scale proj ects. Further guidelines are currently under development to take into acco unt environmental impacts of ASR in smface water riparian zones and catchments and in gro undwa ter systems at local and regional scale.

ASR is practiced in many countries throughout the world generally to provide potable wa ter supplies w ith potable or near-potable quality source wate rs. In So uth Australia's semi-arid climate, and w ith its traditional wa ter supply sources of the Ri ver Murray and the Mount Lofty Ranges und er press ure, a strategic approach is necessary to m aximise the futur e value of ASR . For example research is n eeded to determine w hether continu ed injection oflow quality waters into our existing aquifers could restrict or enhance future opportunities to use freshened gro undwater for potable wa ter supplies. M artin and D illon (200 1) have identified strategic directions for the future of ASR in South Australia to address longer-term goals.

Sou th Australi an s are beco ming increasingly aware of the need to conserve and reuse our available wate r resources more effectively in order to maintain a balance betwee n environmental needs, social well- being and economic needs.

Expanding dem and for gro undwa ter near Adelaide has produced long-term downward trends in piezom etric levels in major aquife rs and a decline in gro undwa ter quality. ASR has the potential to relieve the pressure on gro undwa ter reso urces. There is little doubt now that the conjunctive use of surface and undergro und wa ter reso urces is critical to the optimal development of water supplies for rural and urban populatio ns. The need to reuse our available wa ter resources more than once before summarily treating and discharging them into the coastal marine waters is apparent. In the broader sense, the opportunity exists to use ASR to 30

WATER MARC H 2002

WATER

Figure 2 . Bo liva r reclaimed water AS R resea rch proj ect site, 20km north of Ade laide, where 250,000m3 of irrigati on qu ality water was injected into a confined brackish aq uife r.

rethink our traditional water managem ent and distribution policies, and to provide cost-effecti ve and innovative alternatives to current m ethods.

The basis is now in place in South Australia for application of existing kno wledge and furth er development of policies, technology, education and inform ation to: • protect and enhance wa ter reso urces through ASR applications, • streamline and better integrate wate r administrative pro cedures, • appropriately monitor and report on existing and new ASR operations, • enco urage appropriate investment in innova tive wate r manage m ent, • map the potential for ASR in places w here it has m ost strategic potential , • develop tools to evaluate the storage capacity of aquifers for ASR, • expand the range of aq uifers and wa ter types used for ASR according to need, • facilitate continuous improvement of ASR technology, w here SA is currently a wo rld leader in ASR with water oflow qu ality, • encourage th e industry forward with an accreditation program and, • help Australian industry to capitalise on the innova tion developed in SA to rn.eet state, national and international needs to conserve wate r and enhance supplies .

References Di llon, P.J. and Pa velic, P. (1996). Gu ideli nes on the quali ty of stormwater and treated was tewater for inj ection into aquifers fo r sto rage and reuse. Urban Water R esea rch Assoc. of Aust. R esearc h R eport No 109.

Dillon, P., Pavelic, P. , Sibenaler, X., Gerges, N., and Clark, R. (1997) . Aquifer sto rage and recovery of storm water runoff Aust. Wa ter & Wastewater Assoc. J. Water 24 (4) 7 - 11.

Dillon, P., Pa velic, P. , To ze, S., Ra gusa , S., W ri ght, M ., Peter, P., Martin, R. , Gerges, N. , and Rinck-Pfeiffer, S. (1999) . Storing ·recycled water in an aquifer: benefits and risks.

Aust. Water & Wastewa ter Assoc. J. Water 26(5) 21-29.

Marcin , R .R . and D ill on, P.J. 200 1. Aquifer sto rage and recoveiy: Future directions fo r South Australi a. Department for Water R eso urces Report, O ctober 200 1.

South Australia. 2000. Stace Water Plan 2000, Vo l 2. D epa rtment fo r Water R eso urces, September 2000, pp20.

Toze,S., Dillon, P., Pavelic, P ., N icholso n, B. and Gibert, M. (2001). Aquifer storage an d recove1y: Removal of co ntaminants from stored waters. Aust. Water Assoc. J. f,Vater 28 (7) 41-44.

Acknowledgements T h e authors ack no w l e dge the commitment of the Gove rnment of South Australia , our many peers in Department for Water Resources and CSIRO , and our partner organisations n o t a bl y Urban Water R esea r c h Association of Australia, Hickinbotham Group , City ofSalisbmy, and the partners of the Bolivar reclaimed water ASR research proj ect; South Australian Water Corporation, United Water International and D epartment of Administration and Informatio n Services for enabling the p rogress m ade to date.

The Authors Russell Martin i s M a n age r , Gro undwa ter Assessment Gro up , SA D epartme nt for Water Resources, Manager of Bolivar R eclaimed Water ASR Resea rch Proj ect, C hairman of SA ASR Coordinating Committee, and Sec r eta r y of I SAR4 Organising Committee. Conta ct: M artin .Russell@ saugov .sa .gov.a u. Peter Dillon is leader of th e CS IRO Water Reclamation R esea rch Group , C h airman of th e International Association ofHydrogeologists Commission on M anage ment of Aquifer R echarge, a founding m ember of AW A Water Recycling Forum, and Scientific Convenor of ISAR4 Organising Co mm.ittee . Co ntact : Peter.Dillo n@ csiro. au

INNOVATION:

WATER

DESTRATI FYI NG DAM PROBLEMS S L Elliott, P Morgan Water Engineering and R esearch Solittions Pty Limited (JiVEA RS), destratification system comprises a large 5-metre axial flow p ump, moving water through a fl exible draft tube from the smface through the thermocline to the hypolinmetic bottom layers of a dam. T his destratification p rocess, which has traditionally beet1 achieved with high-ettergy low- efficiwcy air diffusers can now be achieved by pumping up to 15, 000L / s using only Bk W of electrical energy, elim i nating t h ermal s t rata, increasing net dissolved oxygen (DO) , throug hout th e w ater column and minimiz ing or eliminating outbreaks or blooms of Cyanobacteria.

ofBGA,.Ana aena circinalis, is very sensitive to low light conditions.

If the surface laye r of wa ter in w hich they bloom can be continuously rem oved from the surface and pumped to a level below the euphotic zone at a sufficient rate, this has the effect of suppressing blooms. T his hypo thesis has been t es t e d in T i m ar D a m , C oonabarabran NSW , w hich has a traditio nal BGA problem during the summer season .

Anoxic water near surface

In the absence of algal blooms or bacterial contamination, wa ter drawn off from the oxygen- rich Figure 1. A typical WEARS aerator ready for lowering smfa ce layer generally presents few into a reservoir. problems. But it is not always possible to draw off o nly this Downstream Cold Water Pollution Stratification surface water. The i~takes on some dams Cold wa ter released or cold water are deep enough to draw off anoxic water pollu tion (CWP) from the lower levels During summer the surface w ater under norm al summer conditions, and of a dam can upset fish migration (epilimnion) of a dam storage or reservoir even w hen intakes are near the surface, patterns dow nstream and p o tentially wa rms up and therefor e becomes less an oxic wate r can be brought to the eliminate native stock. . This effect can be dense . Below this surface layer, nominally surface by two mechanisms. These are (i) overcome by vertical mixing so that the 3-4 m etres deep, the water remains cold autumn turnove r, w hen the surface water at lower levels is of similar temperand more dense (hypolimnion). These becomes cooler and more dense than the ature and DO concentration to surface laye rs are separated by a thermocline lowe r levels and convec tion starts water. which ac ts somewhat as a barri er to suddenly, and (ii) seiching, or w indno rmal co nvec ti o n circulati o n and Odour, taste and metals in solution induced oscillati o n of the interface prevents the hypolimnetic wa ter from In the absence of oxygen, the reducing betwee n the denser, cooler lower laye r b ei n g cir c ul a t ed o r mi xe d. Thi s environment results in anaerobic decomand the warm er, less dense upp er layer. phenomenon is commonly termed stratposition of organic material, causing ificatio n and is w idely accep ted as the odour and tas te problems. Also m etals Artificial Destratification cause of a n umber of raw wa ter quality such as manganese, aluminium , copper R eservoir and dam op erato rs have problems. and iron from th e bo ttom sediments go accepted that destra tification is the best Autumn turnover, fish stocking rates, into solution . T his m ay cause toxicity to m ethod of initial treatment of storage metals in solution such as manganese and fish, clogging of pipes, aesthetic problems wa ter and this has for some years been iron, toxic Cyan obac teria or blue-green and public complaints. C onversely, by accomplished by bubbling compressed air Algae (B GA), dow nstream cold-water maintaining an oxidizing environment up through the water column. However, pollution (D CP) and environmentally or these problem s ca n be avoided. a system has been developed by WEARS ecologically degraded reservoirs are the Cyanobacteria w hereby a fa r more efficient m echanical main problems. m.ixer w ith a flexible draft tube can b e R educed mixing adva ntages bloom Typical Problems cause by deployed at a fra ction of the ru nning fo rming Cya noba cteria (Oliver et al., Stratification costs. It has, at tim e of writing, been 1998). Some species of Cyanobac teria Fish respiration and migration successfully applied in 13 dams w orld(com.monly known as "Toxic blue green wide. algae" or B GA fo r short) becom e toxic Fish suffe r increasing distress and , and dangerous to human and animal re du ce d grow th rat es as th e DO Top Down Circulation health . T here are several references in the (di sso lve d oxyge n ) co n ce ntra ti o n literature to storages w here the usual algal Unlike the traditional aeration systems decreases below a certain level, the actual blooms ceased or became less severe after w hich attempt to bring anoxic bottom level va rying with species. For example mixing was introduced . Further, it has wa ter w hich has a high chemical and em ergency ae ratio n must be used in been fo und at C haffey D am in NSW nutrient loaded to the surface to interface catfish ponds w hen DO levels drop below (Sherman, 1996) that at least one species w ith the atmosphere, the W EARS 2 to 3 m g/ 1.

32

WATER MARCH 2002

INNOVATION

WATER

'° r--------------------------0.06

system moves saturated The Author surface water from the Steve Elliott is the CEO, 0.05 25 ~... surface to the region Phil Morgan is the R esearch w here it is required for and Production Engineer for 0.04 ox id ation.

By W ater Engineering & R esearch 's kimming-off th e I ,s 0.03 Solutions Pty Limited , Tel: 61 surface layer the rate of 7 5521 0834 , Email: transfer at the smface is 0.02 ! 10 increased and net DO wears@ wears.com. au , W eb distribution Site : www.wears .com.au 0.01 . "' throughout th e References reservoir is therefore 10 12 13 15 m ax imi ze d . This Depth(m ) Brookes, J. , Burch, M . and Tarrant, 15/01 /02TempoC --M- 15/0 l/0200 mgll - - 8/01/02MnSol mg(L -,sro1 to2MnSolmg(L I 1--- 8/01/02 Temp oC - - 8/01/02 DO ~ system uses about 10% P. (2000) Artificial destratifica tion: Evid ence fo r Impro ve d Wa te r of th e e n ergy that Figure 2. Cooby Dam : Temperatures, DO and manganese versus Quality. Water 27(4), 18-22 . tra_ditional compressed depth , before and after one week of operation of the WEARS aerator.

Elliott, S.L. (2002) D es tratification air systems, needs less of Potable Water R eservoirs and maintenance and can D ams, IPWE(Aust) R egional conference, the WEARS system was installed there in be 'set and forget' or connected to existing Toowoo mba Qld. Novemb er 1999 . Since then it has b een SCADA systems for complete control.

Kirke , B.K. (2000) Circulation , Destratification , free of Cyanobac terial blooms and apart Top down circulation is also essential Mixing and Aeration: Why and H ow? from an occasional was h-in event cell in the control ofBGA. By removing the Water 27(4) 34-30. co unts have been zero , with other algal surface layer, w here algae tend to breed Oliver, R .L, R ees, C.M, Grace, M.R, Hait, B.T, sp ecies showing a significant drop in cell and discharged at the bottom of the Ca itcheon , G . and O ll ey , J. (1998), concentrations over the las t 2.5 years . reservoir by pumping them below the

- ---------- --- --

i

14

euphoric zo ne algae are light limited, transported through turbulent flow w here light depriva tion, instantaneous pressure change and turbulent flow limit grow th and minimize or eliminate the occurrence ofBGA blooms.

There is ample evidence that destratification with the WEARS system has always had a b eneficial effect on m etals and algal blooms.

16

Cyanobacterial Blooms in the Darling River.

Water25 (3), 18-19.

Sherman , B. (1996) CR C fo r Freshwa ter Ecology/ CS IRO Center for Environmental M echanics, Ca nberra. Pers. Comm.

Our most recent success Cooby Dam, South East Queensland operated by Toowoo mba City Council, had a histo1y of stratification related w ater quality problems. This storage has a capacity of -24 ,000Ml and is approximately 25111 deep. By pumping the high DO surfa ce wa ter do w n , the total DO throughout the storage has increased to a uniform level of -5mg/ l. Maintaining an oxidizing environment of 2mg/ l o r about 20% saturation has been enough to oxidize manganese and iron from the wa ter column. Figure 2 compares values for temp erature, DO and Mn befor e and after a week of operation of the WEARS aerator.

Brookes, Burch Tarrant (2000), Kirke (2000), Elliott (2002) make clear the relationship berween dissolved manganese and oxygen in reservoirs, by increasing net DO m etals can be removed from the available draw-off wa ter. T emp erature througho ut the wa ter column is now uniform allow ing for any selection of draw-off points, fish habitat has been increased and raw water quality enables reduction in operating costs at the treatment plant. Other storages in N ew South Wales and Queensland ha ve demonstrated similar outcomes .

Timor dam near Coonabarabran NSW, had a long histo1y of algal blooms until WATER MARCH 2002

33

INNOVATION:

WATER

DEALING WITH MANGANESE SLUDGES G Hamilton In a Qu eens land water treatment plant dealing with high manganese levels, it was found that discharging the manganese-contaminated alum sludge to a (distant) sewage treatment plant, before it became anaerobic, not only reduced the recycle of manganese in return supernatant water in the water treatment plant but also reduced the phosphoms input to the receiving sewage treatment plant. The benefits warrant the constmction of pipelines.

Among th ese, the potable wa ter treatment plants, partic1.6 ularly the Mudgee raba Water 1.4 Purification Plant (WPP), has 1.2 the potential to contribute to SeY.er-Disin,a!Stu:ty the incidence of dirty wa ter •• events within its retic ulatio n • sys t e m sin ce p e r s i ste nt . •• :§ 0.6 manganese levels in its recycled • • 0.4 wa ter penetrated the process • ••• I ¥.

• 0.2 and entered the reticulation. ,,,/ ...

0 The Mudgeeraba WPP is challenged w ith manganese input fr om two sources . T he first so urce is the raw wa ter Figure 1. Managanese in Recycled Water at Mudgeeraba WPP content from Hinze Dam and the second source is from Introduction peaks of up to 240,000 visitors. In po tassium p erm an ga nate added for the providing this service, GCW operates two Go ld Coas t W a t e r (GC W ), a treatment of manga nese both in the raw wa ter and four sewage treatment plants, Directorate of Gold Coast C ity Coun cil , wa ter and in the residu e dewatering the latter of w hich have to m eet effluent provides water and sewerage services to filtrate, w hich is theQ. recycled to the inlet N &P criteria of 5 and 2 respectively. a aro und 420,000 residents, plus annual of the plant. Mudgeeraba WPP can only release this manganese via concentrations present in the produ ct water or with the trea tment residue in dewatered sludge cake.

A study into manganese persistence throu gh the potable water treatment pro cess was und e rtak e n a t th e Mudgeeraba WPP during 1997 /98, in w hich m anageme nt of manganese levels from the internal water recycling processes Wide Bay Water Corporation (WBWC) is a water was investi ga ted. As with any treatment and wastewater authority in the Wide Bay plant, Mudgeeraba WPP has to manage Region of Queensland, and is fully owned by alum residue produced during treatment Hervey Bay City Council. in an en vironmentally acceptable manner Wide Bay Water Corporation specialises in: and in strict compliance with Council's license from the state Environmental Wastewater Recycling - National Award Protection Agency. As with traditional winners in recognition for its expertise in effluent water treatment plant design, ie alum reuse schemes . coagulation/filtration for colour and Leakage Control - Specialists in the field of turbidity removal w ith settling and recovery of filter wash water, Mudgeeraba water demand management, and leakage WPP incorporates sludge thickening and control & detection assisting both Australian and dewatering with superanatant and filtrate International water companies with expert advice returned to the inlet of the plant. During and project management. this pro cess , th e trea tment residue Wide Bay Water's Scientific Services - WBWC becomes anaerobic and consequently reScientists and Chemists are called upon for dissolves and returns substantial levels of specialist and research analysis reports and Manganese and other soluble organics to the plant inlet, placing additional alum and environmental investigations. oxidant demand on the process.

Contact - Phone: (07) 4197 4197 In terms of mangan ese persistence Fax: (07) 4125 5118 throu gh the plant, the stored solids in Email: wbw@widebaywater.com.au clarifiers and thickening tanks was shown to contribute significantly - in som e cases 1.8

11

lo.a

~ Wide

~j

34

WATER MARCH 2002

.

.

.. .....,'-...-........ • ,~ ·- ...,...,.,...

Boy Wofe,-

INNOVATION

>90% - to total manganese l oad in g. Mangan ese i s normally treated effectively at thi s sta ge using C hlorin e Dio x id e fo r oxidation, followed by capture of the resulting colloidal m anganese parti culates on the filters.

•

E

.

'\-

•

3

0

0.

...

.

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S E W ER DIS P OSAL STUDY

. ... -

~

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rtarget Eff.-P

.......-."'.... ........ . .•

.

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The study

The risk of manganese ..,. breakthrough from this process ., .,m m m m m m m ,,m and the potential for conse"' u. <I> z < < quent dirty water episodes prompted GCW to investigate Figure 2. Sewage Pl ant Effluent - Phosphorus m ethods of residuals handling 5km, to a point of disposal within the that minimise the return of contaminants sewer catchment. The impa cts of this from the was h water recovery process . study were assessed over a twelve month Although remote from any sewerage systems, the possible benefi cial impact of period at both the Mudgeeraba WPP and disposal to sewer of the solids residu e, the M errimac Sewage Treatment Plant.

Whil e th ere was still sup e rn atant supernatant and filtrate from the solids handling process was inves tigated. c ontainin g so m e mang a n ese at Mudgeeraba WPP it was significantly A stud y was und ertaken during redu ced and mu ch more manageable. It 1997 / 98 to remove thickened residue and was assessed that the ben efits warranted dispose of it to Council' s sewer using a the construction of a pipeline so that both 15 kL road tanker. The thickened residue residu e and supernatant flows wo uld be was mostly remo ved prior to going removed from the potable wa ter process , anaerobic, hence retaining most of the thereby providing even b etter outcomes m anganese, then transported aro und

.

~

~

0.

0.

for manganese management at WPPs .

By 2001 one pipeline had been completed and the other, a $1M proj ect, is scheduled for another water treatment plant .

~

•• •• • • •• • ~ •• • • • •• • •.

•• • •• • •• • • • ~

WATER

0

.

m

m

.

Q

Conclusions

The study showed that di sc harge of th e WTP sludge ano sup ernatant to a 9 sewer provided • A significant benefit for the Mudgeeraba WPP in terms of reduced levels of recycled manganese in the supernatant, see Figure 1.

• A reduction in phosphorus from aro und 5.5 mg/ 1 to 2-3 mg/ 1 at the receiving Sewage Treatment Plant see Figure 2.

These benefits justified the cost of a million dollar pipeline.

0

The Author Geoff Hamilton is Sup ervisin g Engineer for Process Audit in Gold Coast Wate r, Tel 0 7 5581 7 131, Email ghamilton@goldcoast.qld. gov .au

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X

Ross Fraser or Steve Wallace WATER ENVIRONMENT SYSTEMS PTY LTD Unit 4, 9 Packard Avenue, Castle Hill NSW 2154 PH: (02) 8858 3417 or (02) 9450 0740 EMAIL: wes@environmental.com.au WEBSITE: www.eone.com CONTACT:

WATER MARCH 2002

35

INNOVATION:

WATER

GENETIC ALGORITHM OPTIMIZATION APPLIED TO WATER DISTRIBUTION SYSTEMS P Radcliffe The revoilltionary next step in water distribution design has been developed at the University ofAdelaide and is already being used worldwide. This optimi z ation technique is a directed computer search that emulates evolution as it narrows in 011 best altematives.

Genetic Algorithm Optimization Many readers may have come across the latest buzz words in the industry today - "Genetic Algo rithm Optimization".

M any may also qu estion - What is it?

Where di d th e idea com e from? H ow important will it be? And w hat can it do for o ur water netwo rks?

A wo rking definition of optimization is simply the process of finding the best solution to a problem that may have many p ossible solutions. Optimization can therefore be done many different ways.

For a simple problem, one could fully enumerate all possible solutions and then identify the best solution. T he best solution is not necessarily the lowest cost solution, but a solution that has lo w cost and other desirable features as well.

Real-World Distribution Problems Mose planning, design and operations problems that water utiliti es face are coo large and complex to solve by enumerating eve1y possible solution. For a problem as simple as sizing 20 new pip es give n eight allowable pip e diame ter cho ices, there are a total of 8 20 or 1,15 2,92 1,50 4 ,60 6,850, 000 po ssibl e combinations. Now imagine that the designer must also consider minimum tank levels, refilling of tanks under m aximum day demands, adequate tank drawdown to keep storage turning over, maintenance of chlo rine residuals, blending of different wa ter so urces, and pump scheduling to minimize energy costs. With this level of complexity, it is clear a designer can use all the help he can get.

So how does the Genetic Algorithm help?

A genetic algo rithm (GA) is a directed search techniqu e that ve ty efficiently narrows in on the best possible solutio n 36

WATER MARCH 2002

alternatives. Altho ugh the search is vastly more expansive, it is ac tually very similar co the traditional simulation analysis approach w here the designer uses trialand-error to evaluate a handful of trial solutions. Traditional m ethods can usually find a hydraulically feas ible solution, but it is highly likely that the cost of the solution is considerably higher than it needs co be.

The benefits of the GA technique go beyond just reducing the cost of networks.

It is ve1y helpful in stru cturing the search and redu cing the tend ency co modify objectives and constraints as the search progresses . D espite the rigoro us analysis, GA optimiza ti o n do es not disca rd solutions that have minor imp erfectio ns, thus allowing the user to accep t them if he w ishes. It also allows the user to efficiently define the problem several times and impartially revisit the constraints (eg minimum allowable pressure) .

Where did the idea come from and how long has it been used?

H ydraulic modellin g and ge n etic algorithms h ad existe d as se parate techniqu es until research to combine them was started at the University of Adelaide in 1990. Prio r to coming to Adelaide, Associate Professor Angus Simpson had studied in Michiga n USA w ith Prof.

D avid Goldberg - a key developer of GA's, so it was a logical but revolutiona1y step to include GA's in the evalu ation of va riou s mod elling and optimiza tion techniqu es that we re alrea dy being evalu ated by Simpson and his colleague Professo r G r ae m e Dandy in th e D ep artment of C ivil Environmental Engineering. The research and thorough testing of the technique on academic and real life applications was conducted by Dr. Laurie Murph y over the five yea rs leading to setting up of businesses in the USA and Australia to make the technology available.

The company (Optimatics Pty Ltd) has since condu cted dozens of studies in Australia and North America, for proj ects ranging from small subdivisions to large scale proj ects w ith capital cost valu es in

excess of one billion dollars. The largest current proj ect cove rs D etroit and environs where daily water use in the year 2050 is proj ec ted co reach 9.1 GL/d.

Though Australia is still leading the way in large scale optimization studies, several American and E uropean companies have in recent yea rs taken up the challenge and are fas t developing their own genetic algo rithm appli cations. It seems the tec hniqu e is qui ckly beco ming the mainstream way for co nducting pipe netwo rk design and evaluation.

What are the benefits?

The major benefits are that: â&#x20AC;˘ The GA can optimize capital improvem ents needed to meet future demands, and the phasi ng of those improvements to minimize the present value of the cost stream. Cost savings up co 50% have been achieved compared to trial-and-error simulation solutions. â&#x20AC;˘ T he GA can improve the hyd raulic performance of an existing system by optimizing system operations (with or without minor capital improvem ents) to correct existing defi ciencies (s uch as low pressures or insufficient tank drawdown), w hile lowering system operating costs (maximizing off-peak pumping) . â&#x20AC;˘ The GA can investigate a range of different operating scenarios, demand patterns or reliability conditions. Several distinct low-cost alternatives can be develop ed in order to give the decisionmakers a real choice in selecting the solution that best meets their needs.

Projects that would be considered good candidates for GA optimization are those w ith a capital valu e or operating cost estimated at over $1 million. Even if only a 10% saving were made, the returns on undertaking a study are well worth w hile.

What does Full Optimization consist of? ' A mor e formal definition of optimiza tion is: Find the set of values for the decision variables that minimiz e the objectivefi111ctio11 valu e subj ect to a specific set of constraints.

INNOVATION:

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Th e ge n e t i c algorithm optimization process begins when the 22 first 'population' of trial solutions is generated with random values, and each solution is evaluated for hydraulic fitness after evaluation in a hydraulic network sim ulation tool (EPRN ET). T he poor solutions that do not satisfy the constraints are then penalized so they do not get selected as Initial trial-and-error design Optimization performed by GA parents for th e n ext . Figure 1. Skeletonised network of the FCLWD syst em gen eration. The b est solutions are used to The decision va riables are the required allowable size, in any co mmercially create a new population in an evolutionary network decisions such as an actual pipe available pipe m aterial and class. process that continues until only the fittest size and material of the pipe for a T he choice for pipe A-B is dependent solutions survive . particular alignment at a certain time in on the choice for other decisions, such The constraints refer to residual the life of the network. Decision variables as say pipe B-C. Therefore an entire trial pressures, velocities, and tank level flu ctucan also be the status, location and size ations. Solutions are given a cost penalty solution (set of values) has to be evaluated of any network element such as valves, in proportion to the degree of constraint and compared co other solutions usi ng a pumps and tanks. Each decision has violation. Valid solutions m ust satisfy all m easure of fitness to the overall objective. 'allowable' choices, each with known constraints (zero penalties). The perforT he obj ective function is usually expressed hydraulic chara cteristics and costs. For man ce of each solution has to be trialled as least overall cost but it is possible to example, a decision regarding the pipe size during the sp ecified operating scenarios include other objectives w hich say fro m point A to B could be anywhere which might include, peak ho ur water minimize water age or maximize revenue. between the minimum and maximum demand, extended period simulation, and em ergency scenarios such as fire, o utages, and alternative supplies .

Fa.WO ~plan

ungchct

New

l'IIWppe

l)fpeS

â&#x20AC;˘ GA-OptmSedplan.

188rie.s

.!

Estimlted

COUol

$297 milon

Case study #1 Fort Collins-Loveland Water District Expansion - Colorado, USA

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Contact

McKenzie Dredges & Draglines RMB 4245, Timboon, Victoria Phone/Fax: 38

WATER MARCH 200 2

(03) 5598 5490

Fort Collins-Loveland Water District (FCLWD) in C olorado desired a system expansion plan to meet year 2015 demand conditions for its 60 square mile service area . A consultant developed the plan using an EP ANET model having 5 pressure zones, 7 reservoirs, 3 pump stations, 14 pressure reducing valves (PRVs) and 3 interconnects to adj ace nt systems. Th e recommended solution called for 46 new pipes totalling 29 .4 miles in length .

R ecognizing that other layouts might be more cost effective, FCLWD decided to use the Optimatics Genetic Algorithm (O GA). The EPANET model data were read into the OGA program . Allowable choices for pipe locations, pipe diameters and PRV settings, along with corresponding installed costs, were also input.

The OGA optimization then searched for the combination of pipe sizes and PRV settings that wo uld minimize the capital cost of improvem ents while m eeting all hydraulic design criteria and supplying 2015 dem ands. The optimized solution had just 22 new pipes totalling 18.8 miles.

The estimated capital cost for the system

INNOVATION

expansion was reduced fro m $5,850,000 to $2,970,000, a cost savings of 49%. (See system layo ut in Figure 1) FCLWD Sys tems Engineer Terry Farrill said at fi rs t he did not believe th e optimized solu tion wo uld actually supply the required demands. After he tested the solution himself in the original EPAN ET model, he was satisfied it was a viable alternative that met the requi red design criteria. T he optimized expansion solution was then made the basis fo r the District's new capital improvem ent program .

Case study #2 Loxton Irrigation District Rehabilitation GA Optimization Review, Australia

The Loxton Irrigation District is located in the South Australian Riverland.

The fo cus of the study was ' detailed pla1111ing' for the new pumping and distribution system with a total cost of $40111.

Du e to the mix of Federal, State and grower funds , a key goal of the study was to obtai n comparable cost estimates, unbiased towards any particular option.

T h e study considered: • minim um residual pressures of 3m, 20m, 25111, 30111, 35111 and 40m.

• optimal head at primary and booster pumps • trade off betwee n capital and operating costs • alternative pipe routes, materials and classes • staging and duplication of 'existing pipes' • mobile peak demand cases One outcome of this study was that the growers chose a minimum residual head of 35 111 (SO psi) at any service point in the system (from the range of possible values given above) . Altho ugh the incremental cost of a high pressure system had to be met entirely by the growe rs, they recognised the extra cost was only marginal, and that the extra cost to them as individuals wo uld be much less than the annualised cost of maintaining their ex istin g on- fa rm pump st ation s .

Interestingly it was not necessary to consider the many regional benefits that will arise fro m centralised p umping.

Figure 2 shows the OGA optimization of the Loxton System in progress towards the end of the study w hen primary parts had been put to construction, and the remaining smaller bore pipework was being evaluated fo r supply-o nly packages.

The 'existing' trunk main (grey) does not change however the remaining pipes start off in a completely random configuration but then converge to a near optimal solution. At the top of each figure is the

WATER

system cost followed by the pressure penalty cost in bracke ts.

Case study #3 San Diego Main replacement California

T he C ity of San Diego wa ter system serves approximately 1.4 million people with an average daily production of 210 million gallons (S00ML) p er day from th ree water trea tment facilities . The GA study cackled a complex problem that would have been impossible to solve by hand on a modelling package alone.

T he O GA study of the Alva rado system was aimed at identifying the optimal mix of abandoning, re-lining or replacing pipe sections for 25 .7 miles of existing maj or pipelines. The O GA also optimized locati ons and sizes for up to 10.5 miles of new pipes, and fo r potential pip e inter- ties b etween th e m aj o r pipelines.

The most challenging aspect of this pipeline replacement and rehabilitation study was SDW's strict emergen cy criteria. SDW required that the system must continue to operate at full service under the em ergen cy condition of a supply source or a maj or pipeline being out of service. As a result, the O GA needed to develop a highly robust solution w hen outages occurred at any on e of the 20 most disruptive locations that had been identified.

Thro ughout the course of the study, SDW was involved in reviewing the ass umptions used in formulating the OGA model and reviewing interim O GA solutions. Based on a fa miliarity with the optimized plan details, SDW was quick to adopt a preferred solution with an estimated cost of $35.3 million.

(Simply replacing the existing seven maj or pipelines with new pipe of the sam e diameter would be $55 .0 million).

$6,366m ($0,197m)

Generation 50

Legend

$5,211m ($0,129m)

Generation 100

Legend

Conclusion: With savings typically in the range of about 20%, GA optimization is expected to quickly b ecome a standard tool in the plannin g and op erations o f wa ter networks in the same way that simulation modelling has now become a standard tool. With Australia leading the way in this research, we can be p ro ud of the significant benefit we have been able to bring to the wo rldwide water industry.

..-·~. ..•"'.

~ - (l'O!I)

o ""

Legend

The Author Peter Radcliffe is with Optimatics P ty Ltd, Adelaide Australia, E- mail: P eter.Radcliffe@o ptimati cs .co m or www .optimatics. com

Figure 2. GA optimi sation in progress WATER MARCH 2 0 02

39

INNOVATION:

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MIEX® - GOOD RESEARCH COMMERCIALISED M Slunjski, H Nguyen, M Ballard, R Eldridge, J Morran, M Drikas, B O'Leary, P Smith

"

The MIEX® DOC resin process, a brainchild of A11stralian water scientists and engineers, represents an exciting development in potable water treatment technology. It enables new 21st century water quality standards to be achieved with low capital and operating costs and as s11ch has worldwide applications.

The technology was the end result of a massive research and development effort over a number of years spanning areas of product and process development, testing and scale-up by a consortium consisting of teams from CSIRO Molecular Science, SA Water Corporation and Orica. This culminated in the first commercial applications of the technology by the SA Water Corporation at Mt Pleasant (South Australia) and the Water Corporation of WA at Wanneroo (Western Australia), which are outlined h ere in some de tail.

Under the overall coordination of Orica, each of the initial partners was very innovative :in the concept development and how they went about fulfilling their roles of resin chemistry, application and process development and commercialisa tion . T h e Water Corpora ti on's contribution occurred later and foc used on the area of process scale-up and large scale plant design. This article provides a sun1111a1y review of the reasons the parties became involved in the MIE X ® proj ec t , their respective endeavo urs and plans for future.

A short description of the MIEX process is provided in the box on page 46. Further information on the process including m any performance d ata is available from www.miexresin. com.

Figure 1. New Resin Manufacturing Process Research Facility at CSIR0

developed, mostly based on polyvinyl alcohol cross-linked with glutaraldehyde, but none was commercially successful despite an intensive effort over a number of years by CSIRO and its commercial partner IC I Australia (now Orica).

M agnetic ion exchange resins are attractive for two reasons: 1. they can be made very small (0 .1 mm instead of 1-2 111111), and hence can adsorb unwanted species much more rapidly than conventional resins;

CSIRO Molecular Science · MIEX® Resin Development The concept of Magnetic Ion Exc h an ge R es in s was first developed at CSIRO in the 1960s, by a team led by Dr.D E Weiss. M any varieties were 42

WATER MARCH 2002

Figure 2. MIEX® Liquisack Package

2. they can be used in stirred tanks in a continuous process, and then recovered magnetically and recycled. Therefore, unlike conventional ion exc hange, MIEX ® resin systems are p ermanently "online" and cannot suffer from blockage.

In the early 1980s, research carried out

by SA Water showed that if enough DOC were removed from Adelaide water, then much less alum and chlorine were required to treat the water and that this might result in lower levels of potentially harmful trihalomethanes (THMs). SA Water then approached CSIRO and ICI Australia (now Orica) about using CSIRO's magnetic ion exchange technology to remove DOC from drinking water, and a sma ll inform al proj ec t commenced .

After consideration of the possible alterna tives, a new synthesis route based on acrylates combined with magnetic iron oxides was developed. T his route was chosen becal!lse of: 1. the need to incorporate strong base functionality: the positive charge on the resin attrac ts the negatively charged DOC; 2. price and availability of the precursor chemicals;

INNOVATION:

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Table 1. Impact of DOC Removal on Disinfectant Demand and DBP Formation MIEXe Resin Dose (ml/L)

Dlssolved Organic Carbon (mg/L)

Chlorine Demand (mg/L)

Trlhalomethane Formation Potential (11g/L)

0 1 2 3

8.1 5.1 3.9 3.0

4.1 2.6 1.7 1.0

397 207 156 117

then 20 dm 3, then finally 200 dm 3 . This resulted in some changes : some of the minor chemicals in the process had to be replaced, and an external company was bro ught in to manufacture one of the components of the synthesis on a large scale.

The final stage at CSIRO was the manufacture of pilot quantities of resin for Orica to seed the technology into the va rious markets. T his was not a simple process, and some serious Figure 3. Preparation of MIEX® Resin Shipment pro blems we re enco untered.

However, after some frenzied inves ti gation, the ca uses of 3. low to moderate toxicity of the problems were ascertained, and they were precursor chemicals; fixed. In all, CSIRO has now manufac4. ease of synthesis. tured more than a hundred large batches A breakthrough was achieved in early under contrac t to Orica, all (except the 1993 with resins produced via this route first few) wi thin specification and on showing promising perfom1ance in simple time. The lea rning obtai n ed also laboratory tests. The project was enlarged, contributed substantially into the design, and the synthesis was then optimised, installation, commissioning and operation based on feedback from testing at SA

by Orica of a much larger resin manufacWater and the comm ercial requireturing facility at Deer Park (V1ctona, ments of Orica.

Australia) w hich came on stream late m The next stage was scale-up, and here 2000. the Process Bay facilities at CSIRO CSIRO is continuing research into Molecular Science played a key role. In MIEX®- type resins, and has just commisthe laboratory, the normal resin batch size sioned a new 500 dm3 reactor facility to was 300 ml, though larger batches (up to make new resins for water and wastewater 1-2 dm3l could be made. However, much treatment and mineral processing applilarger quantities were required for the cations (fig.1). proposed pilot plant at Hope Valley. T he team therefore used the Process Bay facilities to scale up first to 15 dm3 batch size,

Orica • MIEX® Commercialisation: A Road Full of Potholes!

Innovative as it is , bringing the MIEX® DOC technology to the market has been a long process due to the conservative nature of the water treatment industry. Very early in the R&D phase, it was recognised that the technology would potentially benefit from the demand for better water quality around the wo rld . T his was most evident in the U SA w here the D / DBP (Disinfection/ Disinfection Byproducts) and ESWT (Enhanced Surface Water Treatment) rules were in the process of being introduced . However, it wo uld be tough to break into the market.

A commercialisation strategy was devised which aimed to have the MIEX® DOC Process approved and introduced first in the Australian market before being launc h ed elsewhere. T his approac h allowed the technology to be tried near its sources of technical support and avoid the NIMBY (Not In M y Back Yard) criti cism often levelled at new developments in new markets.

After the labora tory (Nguyen et al, 1994) and first appiication pilot plant (N guyen et al, 1997) stages, the resin manufacturing recipe was "frozen" to enable the design of a manufacturing plant and for the regulatory approval process to start. Approval for the manufacture and use of the MIEX® resin in Australia was sub se qu en tly obtained und e r the NICNAS (N ew Industrial C hemicals Notification and Assessment Scheme) in April 1997. T he effort to gain the first commercial installations for the technology in South Australia and Wes tern Australia and to establish the Deer Park resin manufacturing facility to support these first plants and to fine tune the resin production then followed (fig.

2, fig. 3). T hese have been already detailed in this article.

Table 2. Effectiveness of MIEX® Resin at DOC Removal for Australian Waters MIEX® Resin Dose (ml/L)

0 0.5 1 2 3 4 5 Figure 4. MIEX® Plant at Mt Pleasant

44

WATER MARCH 2002

SA

182 163 55

SDS THM FP* (11g/L) QLD VIC

182 118 105 72 59

243 154 143 77

55

WA

395 373 294 272 183 169 152

Dissolved Organic Carbon (mg/L) SA VIC WA QLD

10.8 8.3 6.4

* Simulated Distribution System THM Formation Potential levels

4.5 3.7 3.2 2.4 1.8

11.4 9.3 8 .5 6.6 5.3 4.4

7.0 6.0 4.9 3.7 3.0 2.4 1.8

INNOVATION:

In the USA, which had been identified as the market which offers the best potential, the entry strategy revolved aro und four elements: (i) a full understanding of the regulatory framework on wa ter quality, industry structu re and drivers; (ii) a timetable for approval of the process; (iii) a program of development work in association with lo cal R & D institu tions and public utilities; and (iv) the formation of a local commercial body to coordinate all aspects of the process.

Under this strategy, performance data were obtained with a range of US waters under different conditions as early as 1997 , and the work is continuing (Bourke, 200 1; Hamm et al, 200 1; Semmens et al, 2000; Singer & Bilyk, 2000; Amy, 2000). Accreditation with the NSF (US National Sanitation Foundation) under Standard 61 - Drinking Water System Components - Hea lth Effects for the AUD10 million pilot manufacturing facility at Deer Park (Victoria) was gained in November 2000. To complete the process of commercialisation, Orica Watercare USA Inc., was established early in 2001 and currently is on the way to win its first order (AWWA, 200 1).

WATER

controlling the chemistry and physical performance of all water treatment processes. It reduces the effectiveness of water treatment by interfering with the flo cculation process (Chow et al, 1999) and makes treatment with activated carbon (Newcombe et al, 1997) and membrane filtration less efficient (Drikas et al, 2000). Furthermore, NOM acts as a food so urce for micro-organisms resulting in bacterial regrowth in distribution systems (Withers et al, 1998) .

For these reasons the Australian Water Quality Centre (AWQC), the analytical,

research and development arm of SA Water, has explored alternative strategies for DOC removal. Strategies have been varied and have included catchment management to reduce DOC input into the so urce waters, op timisation of conventional treatment for DOC removal (eg enh an ced coagulation), DOC removal by membranes, resins and activated carbon and destru ction of DOC by UV , ozon e and other treatments. In addition the AWQC has carried out extensive research into the characterisation of the NOM present in water to enable a better understanding of

MIEX® DOC Resin Process

SA Water Corporation - MIEX® Process Development and Commercial Application at Mt Pleasant WTP The So uth Australian Water Corporation turned its attention to the presence of natural organics in drinking water in the early 1970s after monitoring of South Australian drinking water supplies revealed high levels of disinfection byprod ucts (DBPs) in some systems. The DBPs were produced by the reaction of chlorine with the naturally occurring organic matter (NOM) in water, producing THMs, some in excess of 250 µg / L, and chloroform levels in excess of 100 µg/ L. In one study (Bursill et al, 1985) monitoring of several South Australian water sources indicated that the high DBP levels were principally due to the high concentration ofNOM in South Australian surface waters, ranging from 10 to 20mg/ L as dissolved organic carbon (DOC). The study showed that a clear relationship existed between DOC and THM formation by employing an anion exchange resin to generate test waters with a range of DOC levels. This was confirmed in later studies with MIEX® resin (Table 1).

Further laboratory studies into the effect of DOC on water treatment confirmed literature results indicating that NOM is one of the major characteristics 46

WATER MARCH 2002

Regenerant Tanlc MIEX® Plant

Natural Organic Matter presents a significant problem in water treatment by causing colour in water, increasing required coagulant doses, providing precursors for disinfection by-products and causing re-growth in the distribution network. Dissolved organic carbon (DOC) is a "bulk" measure of the organic matter content widely used in water treatment.

T he MIEX® DOC Process is a novel ion exchange process for the removal of DOC, ie. natural organic matter in drinking water treatment. In the heart of the process is a micro, strong base (type I) , macroreticular, Magnetic Ion EXchange (MIEX®) resin, specially developed and optimised for the DOC removal. The uniqu e magnetic properties of the resin enabled the process design that is significantly different from conventional ion exchange processes.

In the MIEX19 DOC Process the resin contact with water (the DOC uptake) is conducted in suspension, in a continuous stirred tank reactor called a contactor. The contactor is designed with a detention time (ie. contact time) required for achieving a desired DOC removal. After contacting, the resin-water suspension is introduced to a gravity separator where the resin is recovered and in a concentrated form recycled back to the contactor. Product water overflows from the separator and is taken away for further processing. A small amount of the used resin is continuously removed from the recycle line and is replaced in the contactor with the same amount of fresh, regenerated resin. The resin regeneratio~ (the DOC release) is conducted in batches with 10% NaCl. In this way the DOC removed from raw water is concentrated by up to 10000 times in was te brine ready for disposal.

INNOVATION

WATER

the mechanism of each of • Dual-media sand and coal 70 the removal processes. filters w hich incorporate many of the 'Badenoch ' While the research is 60 recommendations to reduce ongoing, one line of particulate break- through research that has borne 50 (Badenoch et al, 1995). fruit was the development Stream 2 comprises the of th e MIEX® DOC greenfield MIEX® process Pro cess . It has progressed and the Vivendi Water through m any stages CMF-S plant. Aspects of beginning with laboratory this stream are: co mpari so n of an ion 20 • Th e R &D fun ction , exchange resins in 1982 to investigating the synergies large scale pilot plant trials 10 b e tw ee n MIEX ® and at South Australia water microfiltration with respect treatment plants at Hop e 4 Dec01 30ec01 5 Dec01 6 Oec01 11 Oec01 to reduced organic fouling Valley W FP in 1985 and of the membrane with the 1994 (Nguyen et al, 1997), Figure 5. MIEX® Performance at Mt Pleasant WTP - December 2001 associated reduced cleanand then Happy Valley in-place (CIP) cleaning WFP and Murray Bridge and possible in crease d in 2000. The current form • the MIEX® DO C removal process for m embrane life; of the resin has also been extensively the first time in a commercial application; • The ability to trial granular activated tested with a wide range of Australian • the Vivendi Water C MF-S (crossfl.ow carbon (GAC) filters on a side-stream of wa ters. In one such study the AWQC microfiltration - submerged) process the microfiltered water to simulate the found that MIEX® resin was particularly with chlorine resistant membranes - the MIEX® - microfiltration - GAC filtration effective at treating WA gro undwater first commercial use of this by Vivendi process combination considered to be the (Morran et al, 1996, Table 2) . It was not Water and the SA W ater's first use of optimum future augmentation direction until 2001 that the process was finally microfiltration; for Adelaide's water treatment plants. incorporated into the world's first MIEX® • m any facilities to carry out vital R &D The MIEX® treatment has resulted in purpose built drinking water treatment studies utilising MIEX®, microfiltration predicted initial•DOC removal rate the plant at Mt Pleasant. and conventional treatment processes. in the 40- 50% range (fig. 5) and higher T he Mt Pleasant W ater Treatment removal rates can be expected with The plant has b een divided in two Plant has a rated capacity of2.5 ML/day furth er optimisation of each treatment streams, each of 1.25 ML/ d capacity. and began providing filtered water to the stage. Op eration of the plant and the Stream 1 is designed to simulate the tow nships of Mt Pleasant, Springton and associated R &D program will provide SA retrofit of MIEX® into a conventional Eden Valley in July 2001 (fig. 4) . The raw W ater with significant knowledge on the coagulation, flo cculation, sedimentation wa ter source is the River Murray, processes for incorporation into existing and filtration plant without any major obtained from a branch off the nearby and future treatment facilities (Kilmore infrastru cture modifications or additions.

Mannum-Adelaide pipeline. The River et al, 2000). The economies of the process Other aspects of Stream 1 include: Murray water quality is characterised by can be evaluated at full scale ye t, due to • T he ability to remove and modify the high turbidity, medium colour, high the size of the plant, development MIEX® settling equipment easily as part modifications for optimisation purposes organic levels and possible algal contamof the development program; can be implem ented relatively inexpenination.

• The ability to trial direct and contact sively.

T his plant is the most diverse in filtration b y appropriate b y- pas s process, innovation and complexity that pip ework. Following trea tment by Water Corporation of WA· SA W ater has built to date. The main MIEX® these options may be possible Commercial Large Scale reaso ns for this are that the plant with much lower coagulant doses and Application of MIEX® Process at form part of the research program ; includes:

the Wanneroo GWTP

Table 3. Cost Comparisons for DOC Removal Processes for Wanneroo GWTP (for approximately 40-50% DOC Removal).

OPTIONS

Capital Cost AU$ M

Operating Cost AU Cents / 1 kl

NPV** AU$ M

MIEX® Resin Treatment

15

10.5

52

0 3 / BGAC* (existing fi lters) Assume 2 months carbon life

14

33.2

164

0 3 / BGAC (dual filters) Assume 4 months carbon life

20

16.6

82

GAC in existing filters Assume 2 months carbon life

5

31.8

157

* it is assumed the existing sand/anthracite filters can be converted to carbon. ** 30 year Net Present Value with 8% Weighed Average Cost of Capital (WAGG) 48

WATER MARCH 2002

The Water Corporation of W es tern Australia (WCW A) has over a number of years been inves tigating various water treatment technologies aimed at dissolved organic carbon (DOC) remova l.

R esearch was prompted by intermittent o utbr eaks of DMTS (Dimet h y l Trisulphide) in the clearwater distribution system. The presence of DMTS in tap water is noted as a "swampy" odour, and is susp ec ted to be the produ ct of biological ac tion in the distribution system. DO C in the treated water promotes biofilm grow th in the distribution system , and this coupled with NSRS (non-sulphide-reduced-sulphur) in

INNOVATION:

WATER

_______________________

,..

,. the water leads to DMTS MlEX® resin treatment over formation (Smith et al 2001). ozonation/ BAC and BGAC (ta ble 3; Cadee et al, 2000) Pr e limin a r y te s t s 12 +-al-,-~ - - - - - - - - - - - - - - - - - - - - - t 6 0 0 fo r u pgrading of th e c ond u c t ed on the raw Wanneroo GWTP for a Wa nneroo wa ter by SA 10+-ai--at--- - - - - - - - - - - - - - - - - - - - - t ... mor e e ffi c i e n t D O C Water staff indicated that the remo val. Black & V eatc h MIEX® r es in was ve ry Australia has been appointed effective in removing both as the Engineer, Procure and DOC and NSRS. Based on C onstruct (EPC) contractor that a full feas ibil ity study for. de 1ve ry of the 112.5 including pu rpose designing MLD , AU$15M MIEX® and constru cting a 1 MLD plant (Smith et al, 200 1).

MIEX ® pilot plan t, was undertaken by WCW A and Th e MIEX plant is Orica in the period 1997being constructed on the 20 30 1999. The results indicated " " existin g plant si te as a ~t.m Dose (rTD'L) betwee n 60% and 75% of re trofit. Located at the head . NSRS • DOC • TTHMfp DOC , and more than 90% of the wo rks afte r th e NSRS (fi g. 6) ca n consisaera tor, the plant w ill treat Figure 6. Typica l Treated Wate r Qua lity after Enhanced t e ntl y b e r e mo ve d by the raw wa ter prior to alu m Coagulation , MIEX® Res in and Combined Treat ment combining the MIEX ® resin coagulatio n, clarification and treatment w ith the existing filtration in the existing plant. wa ter chlo rine d em a nd , and 40 % alum coagulation and dual media filu·ation T h e MIEX® train comprises two 400 reduction in disinfection by-produ cts (Cadee et al, 2000). All treated water 111 3 contactors (Smith et al, 200 1), six formation pot e ntia l co mpar ed to quality objectives were m et w ith up to " Fit c h -fee dw ell/in ve rted p y r am id enhanced coagulated water (80 mg/ L 70% less alum used for coagulation w hen bo ttom" type sep arators, tw o 751113 alum). the raw wa ter was pre-treated w ith regeneration vessels, a 100m3 fresh resin Ba se d on the fea sibi lity study MIEX® resin. T his treatment regime also tank, and additio nal infrastru cture for th e o utco m es , WCW A has chosen th e resulted in > 50% redu ction in treated preparation and storage of regenerant solu tio ns (fig. 7) . The total footprint is 15001112 .

T h e water flo w from the aera tor thro ugh the MIEX® plant is by gravity, East side w ith total head loss of 2.4m.

A pump station is constructed o n th e outlet of the MIEX® plant to provide 4m lift required to achieve gravity flo w t h ro u gh the ensuin g con ve nti o na l treatment - alum coagulation/ clarifica tion , and d u al m edia fi ltratio n .

Construction of the plant was completed in O ctob er 200 1, and the pro cess co mmi ssio ning is c urre ntl y in an adva nced stage.

T his proj ec t presented numerou s challenges for the scale up of the MIEX ® pro cess and w h en co mpl e ted w ill represent the w orld 's first large scale conrn1ercial application.

The Authors

Figure 7. MIEX® Plant at Wan neroo GWTP

50

WATER MARC H 2002

Marin Slunjski , Hung Nguyen ORICA Australia; Matt Ballard, Rob Eldridge - CSIRO Molecular Scien ce; Jim Morran, Mary Drikas - SA Water Australian Water Q uali ty Centre; Bernie O'Leary, Paul Smith - Wat e r Corporation of WA. (Address for correspondence: Marin Slunjski, Orica A WT, PO Box 2291 , R egency Park, SA 5942 or marin .slunj ski@ orica .com.)

MIEx® is a registered trademark of Orica Austra lia.

INNOVATION

References Am y G, (2000) - an intern al report to Ori ca Watercare l nc.

AWW A (2001) Co11s11/ta11t's Corner - E11gi11eeri11g t11d y f or 10 M C D MIE>..'® Plant fo r tl,e Cit y of Da,wille, Kentu cky, Journ al, AWWA, N ov, 2001 Bo urke M , (200 1) Use of Co11ti1111011s lo11 Exc/,a11ge Process (MIE>..'®) to R e111011e TO C a11d S 11/fides fro 111 Florida Water S11pplies, Prese nted at th e Florida W ater R esources C onference, 8- 1l April, Jac ksonviLl e, FL, USA Bursill DB, Hin e PT, Morran JY (l 985) Tl, e Effect <if Na t11ral O rga11ics 011 Water Treat111e11t Processes . Proceedings of the Au stralian Water & Wastewater Association 11th Federal Convention , 197-204 Cadee K, O 'Leary B, Smith P, Slunjsk.i M , Bourke M , (2000) World 's First Mag11etic Io11 Excl,ange vflater Treat111 e11t Pla11I to be J11sra//ed i11 ltlles/em A 11stralia, Pro ceedin gs AWW A Conference, 11- 15 June, 2000, Denver, USA Chow WK, van Leeuwen J A, Drikas M , Fabris R, Spark KM, Page D W , (1999) Til e fll1pact of the Character of N at11ral Orga11ic Matter i11 Co1111e11 tional Treat111e11t wit/, A l11111, Water Science and T echnology 40 (9) pp97- 104 B a d e n o c h J for th e D e partm e nt of

WATER

Environm ent/ D epartment of H ealth (1995) Cryptosp01idi11111 i11 Water Supplies Seco11d Report of the C ro11p of Experts C hairm an Sir John Badenoch HMSO , published in O ctob er 1995 Dtikas M, MomnJ Y, Pelekani C, Hepplewhite C, Bu rsill DB, (in press) R e111011al Of at11ral O rgan ic Matter - A Fresh A pproach, in W ater, Science & T echno logy Journal Hamm E, Bourke M , (2001 ) App/icatio11 of Mag11etiz ed A 11io11 Exc/1a11ge R esin fo r R e111oval of DOC at the Coldiro11 Watki11s Me111 orial Water Treat111e11t Pla11t i11 Daiwille, Ke11t11cky, Proceedings of AWWA Water Quali ty T echnology Conference, 11 - 15 November, D enver, Co, USA Kilmore G, Drikas M , Lehm ann T , (2000) The F11ture i11 Water Treat111e11t - An SA Perspecri11e, in Proceedin gs ofEnviro2000 Conference, 9- 13 April, Sydney MorranJY, Bursill DB, Diikas M, N guyen HV , ("1996) A New Tecl,11iq11e fo r the R e111oval of N at11ral Orga11ic Nlatter, in Proceedin gs of AWW A W atertec Con ve ntion , Sydney, 1996 N ewcombe G, Drikas M , H ayes R : (1997) Th e i1ifl11e11ce <if characterised 11atural orga11ic 111aterial 011 activated carbo11 adso1ptio11, Water R esearch, 31, (5) pp 965-972 & 1065-1073 Nguyen HV, Bursill DB , Diikas M , MorranJY,

Pea rce VL, (1994) THMs a11d Dri11ki11g Water - A New Process for Precursor R e111oval, Proceedings of EnviroMal'94 Co nference, 19-21 O ctober, Ku ala Lumpur, Malaysia N guyen HV, Sl unj sk.i M , Bourke MF, Drikas M , (1997) DOC R e111oval by MIEX Process - Scali11g Up and Other D eve/op111 e11t Iss11es, in Proceedin gs of 17th Federal AWWA Con vention, 16-21 March, Melbourne, pp 373 -379 .

Semmens M , Burckh_ardt M, Schuler D , Da vich P, Slunjski M , Bourke M , Ngu yen H , (2000) A11 Eval11ation of Magnetic Jon Exchange (M IE ) for N OM Re111011al, Proceedings of AWW A Conference, 11 - 15 June, D enver, Co , USA Singer P , Bilyk K, (2000) Enhanced Coag1-1latio11 Us ing a Jvfagnetic Io11 Excha11ge R es i11, Proceedings of AWW A W ater Quali ry T echnology Conference, Salt Lake City, Utah , USA Sm.ith P, Botica C , Lange R , Tattersall ] , (2001) Desig11 a11d Co11Stmctio11 of the World's First Large Scale lvllE Water Treat111e11 I Plant, Pro ceedi ngs of 19t h Fe d e ra l A WA Convention , 1-4 April , Canberra Withers N , Drikas M, (1998) Bacterial R egrow//, Potwtial q11a11titative 111earnre by acetate carbo11 equ i11ale,us, Water 25 (5) pp l 9-23

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WATER MARCH 2 002

51

INNOVATION:

WASTEWATER

CONVERTING SEWAGE SLUDGE TO FUEL OIL T Bridle, T Casey, M Domurad Introduction

hydroca rbons. The catalys ts necessa1y fo r the conve rsion (alurruno-silicates and heavy metals) are inherently present in all sludges . The three low grade fu els (char, NCG and R W ) are co mbusted in the Hot Gas Generator (HGG ) to pro vid e t h e e n ergy needed for d1y ing the sludge.

At Subiaco the oil is currentl y being exported from site for use by industry to replace fossil fue ls 111 stea m raising boilers.

The ENERSLUDGE™ process is derived from t ec hn o l ogy or igina ll y developed at the University ofTubingen in Germany in th e ea rl y 1980's.

E nvironmental Solu tions International Ltd (ESI) in A u s tr ali a co mm e n ce d engineering development and scale-up of the process in 1987 and built a one tonne per day pilot plant w hi ch was su ccess full y demonstrated in both Perth Operational and Sydn ey . The process Experience und e r we nt si g nifi ca nt T he fa cility was commisrefinements during the early sioned in stages with the 1990's and ESI was in a dewateting and back- up position to co mmercially lime stabilisation processes exploit the technology by becoming operational in the mid 1990's. A contract Janu ary 1998. The lime to b uil d the first tion pro cess was stabilisa co mm e r cial p la nt wa s required to pro cess th e awarded to the ESI/Clough dewa tered sludge during J oint Venture by the Water commissio ning and now Corporation of Western w hen the drye r is down for Australia in late 1996 and Figure 1. Subiaco ENERSLUDGE™ Plant m aintenance. No problems this "world-first" plant was we re e ncountere d w ith recently handed over to the these components of the client afte r su ccessfu l the Subiaco WWTP, which currently plant and dewatering performance by completion of the contractual perforamo unts to between 15 and 18 d1y tpd. cent1 ifuge has exceeded expectations. A mance testing obligations. The facility T he actual co nversion process uses a co mbination of both pro cess and uses ESI's patented pro cess w hi ch dual reactor system at a relatively low equipment problems delayed commisthermo-chemically converts sludge into temperature of 450°C and atmospheric sioning of the drye r and H GG. D1yer fo ur " clean" fuels, namely oil, char, nonpressure to convert the organics in the downtime was attributed to the high condensed gas (N CG) and reaction water sludge to the fo ur fuels. In the first levels of hair and fibre in the sludge and (RW). T he R W contains up to 10 % by reactor the dried sludge is heated to a strain press was installed in J anuary weight of water soluble organics and has temperature with the evolutio n of abo ut 1999. T his remo ved much of the hair a positive fuel valu e.

60% of the sludge solids as raw pyrolysis and fibre and had a m aj or positive gas. T he gas and the char are conta cted The Subiaco Plant impact on d1yer operations. Unexpected in the second reactor to facilitate the ofbio-P removal in the WWTP periods The int eg rat ed S ubi aco catalysed vapo ur phase reactions w hich ca used high levels of phosphorus in the ENERSLUDGE™ pl ant is full y refine the gases to produ ce essentially s lu dge which ca u sed e nclosed (Fi g u re 1) and prob le m s in t h e HGG . comprises a number of sludge Table 1. Typical Conversion Product Data Sludge wi th hi gh P and K pro cess in g operations levels produced an as h with including dewate1ing, drying, Product Yield Gross Calorific % of Sludge (% of dry sludge) a so ft e nin g t emp era tur e Value (MJ/kg) Energy conversio n, energy recove1y 250°C l owe r th a n that and gas cl eaning (Figure 2) .

Oil 29 30 45 T hi s " non- in cin e ration " m easured during the design Char 43 18 40 th ermal plant processes all of phase of the plant. The NCG 14 15 11 the raw primary and waste HGG secondary air system RW 14 6 4 activated sludge generated at needed major modificatio ns

54

WATER MARCH 2002

INNOVATION

WASTEWATER

of ash and over 250 tonnes of oil. Note that most of the limed sludge was produced during the extended dryer commissioning period and most of the dried slu dge produced during the HGG commissioning period. Most of the limed and dried sludge has been beneficially reused on agricultural land.

The conversion reactors have operated essentially as predic ed, w ith the average product yield and energy data for the past six months shown in Table 1 below.

A unique feature of the conversion process, as shown in Table 1, is that all of the sludge energy is recovered in the four products.

Energy Balance

Figure 2. Sludge Processing Operations

Char, NCG,

RW

l.05t

HGG

Waste Heat 3.4GJ

I0.6GJ

Sludge (95% TS) 19.3GJ

Hot Air

CONVERTERS

7.2GJ

Oil 8.7GJ 1.~t

si-,., (9'., TS) 19.3 GJ

IGJ

Figure 3. Energy Block Diagram Table 2. Heavy Metal Fate in the ENERSLUDGEâ&#x201E;˘ Process Heavy Metal

Arsenic Cadmium Copper Chromium Mercury Nickel Lead Zinc

Typical Sludge Concn (mg/kg)

Percent of Sludge Metal In:

011

Char

NCG

RW

Percent of Sludge Metal In Ash

1.0 1.5 900 35 2.5 15 50 550

<1 <1 <1 <1 5 <1 <1 <1

>99 >99 >99 >99 5 >99 >99 >99

<1 <1 <1 <1 0.5 <1 <1 <1

<1 <1 <1 <1 2 <1 <1 <1

>99 >85 >99 >99 0 >99 >95 >99

to cope with this situation. After these "teething problems" the dryer and energy recovery system were successfully integrated by early 2000.

Commissioning of the conversion reactors commenced in early 2000 after stable operation of the dryer and HGG was achieved. Concerns regarding scaleup of the conversion reactors were quickly dispensed as they performed to expectations. The oil condensing system 56

WATER MARCH 2002

was modified and after that modification stable operation of the totally integrated plant was achieved in late 2000. The ESI/Clough JV handed over the integrated plant to the WC in June 2001 after 6 months of operations.

Since operations commenced over 550,000m3 of liquid sludge has been processed in th e plant, producing 23,000m3 of lime stabilised sludge, 8 700 tonnes of dried sludge pellets, 275 tonnes

Intensive monitoring of the plant during the performance testing allowed detailed mass and energy balances to be developed. Based on this data a simple energy block diagram for the processing of one tonne of dried sludge is shown in Figure 3 .

Data and experience has shown that provided the sludge is dewatered to ab-..

26% TS there is sufficient energy from the HGG to provide all the energy needed for the drye'r. As can be seen in Figure 3, one tonne of dry sludge has an energy content of 19 .3 GJ. In the converters 45 % of this energy (8. 7 GJ) is recovered in the oil with the remaining 10.6 GJ b eing transferred to the char, NCG and R W. Combustion of these products in the HGG produces 10 .6 GJ of energy of w hich 7.2 GJ is transferred to the dryer via an air-to-air h eat exchanger. This energy is sufficient to remove 2.8 t of water from the sludge producing dried pellets of95 % TS. The Subiaco data has thus confirmed that the gross energy output of the plant is 8. 7 GJ/t dry sludge. The reactors are heated using LPG and this energy demand is 1 GJ / t of sludge. Thus the nett energy output of the process is 7.7 GJ!t.To ESI's knowledge this is the only thermal process that will generate this level of export energy from sewage sludge .

Environmental Considerations The process provides major environmental benefits compared to other sludge processing options, the most important being the unparalleled control of contaminants present in sludge. The first unit operation to impact heary metals is the conversion process. Operating at a t emperature of only 450°C under reducing conditions the only h eavy metal vaporized is mercury. This is speciated as mercuric sulphide and is recovered from the oil polishing disc

INNOVATION:

PARTICLE COUNTING

WASTEWATER

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View of the reactor

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centrifuge as a oily process slu dge, w hich is disposed to an industrial waste trea tme n t fac ility T h e fo u r m ain conversion products thus have very low m erc ury levels. Most of the other heavy m etals present in the sludge are classified to the char produ ct, as shown in T able 2.

Upon combustio n of the char in the HGG , most of the heavy m etals are classifi ed to the ash , as show n in T able 2. Only a small quantiry of cadmium and lead are vaporised in the H GG . T he m etals in the ash are speciated as silicates and oxides and are thus non-leachabl e, m aking the ash suitable for reuse in concrete prod ucts.

Due to the good co ntrol of heavy m etals (and organochlorine components) in the process only simple gas cleaning is required to m eet the stringent emission

limits se t b y th e D ep artme nt o f Environmental Pro tection (DEP). Gas cleaning comprises a simple ve nturi scrubber for particulate removal and an SO 2 scrubber. Plant emissions , together w ith the D EP and German emission limits are shown in T able 3 .

As can be seen plant emissions are well below the standard $et in both Australia and E urope. O f m ost signifi cance is that the dioxin emissio n level is over 300 times lower than the German standard.

Authors Trevor Bridle (T echnical D irector) a n d Dr. Tim Casey a r e w it h Enviro nm ental Solutio ns Internatio nal Ltd, 21 T eddington R d, Burswood WA 61 00 and Margaret Domurad is w ith the Water Corporation of WA, 629 N ewcastle St, Leederville WA 6007 .

Email trevorb@environ.com. au

Table 3. Plant Emission Levels and Standards (mg/ Nm 3 ) Parameter

Particulates

DEP Standard

12

75

TA Luft (17 BlmSchV) Standard

30

so, co

<36 45

100

HF

Not detected

5

4

HCI

19

Cd

0 .01

50 0 .03

60 0.05

Cu

0 .36

2 .0

0.5

Cr

<0 .007

0.5

0.5

~enelei>

Hg

0 .008

0 .05

0 .05

Ni

0.11

0.5

0 .5

Phone: 1300 73 2233

Pb

0.08

0.5

0.5

Tl

0 .0001

0 .05

0.5

Zn

0.1

1.0

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58

Plant Emission Value

WATER MARCH 2002

Dioxins (ng TEQ/ Nm 3 )

0 .00032

200 50

0.1

INNOVATION:

WASTEWATER

IMPROVING THE EFFICIENCY OF STPs L Charuckyj compete with other bacteria (s uch as fil am ents) for the available food. The resultant sludge mass settles w ell, leaving a ve1y clear liquid due to attraction of fine dispersed matter onto the zeolite material.

A reduction in filament numbers has often been associated with settleability improvements produ ced by ZELflocc, but even w hen settling well it is not unusual for a large number of fil aments to be associated with the flo es, altho ugh they no longer seem to extend excessively beyo nd th e boundaries of the flo es.

Among the advantages arising from improved settleability, depending on the way this is applied, are greater plant capacity and increased sludge age for th e sam e load (thus enabling, for instance, nitrification in a plant not currentl y ac hieving this). ZELflocc has been used to achieve both 0ÂŁ these or, in other instances, to improve the efficiency of subsequ ent sludge handling fac iliti es.

ZEL.flocc utilises the mmsual properties of a 11atural mineral zeolite to improve the performance a11d I or capacity of existing treatment systems, or to reduce capital expenditure on nerv treatment systems.

Uma.lly applied to activated sludge systems, the ZEL.flocc process utilises specially prepared zeolitic material to attract dispersed partiwlate matter a11d heavy metals, significantly improve sludge settleability, minimise sludge odour, and reduce both polymer requirements for dervatering a11d metal salt requirements for phosphorus p1'ecipitatio11. Dried sludges also have an open structure rvhich is particularly suited to composting and vermiwlture (composting ivith rvorms).

The ZELflocc Process Zeolites, sometimes called greensands, ca n be mined in various places. They are mineral ion-exchangers and were used for wa t e r-s oft e ning b efo re sy nth e ti c exchangers were developed. Some of them ha ve special properties, especially one termed clinoptilolite, w hich has a useful affinity for the ammonium ion, unmatched by any current synthetic exchanger.

In th e ZELflocc process one such zeolitic material , mined in Australia , and prepared to th e optimal size range, is added to wastewater during, or just prior to trea tment. This ZELflo cc powder attra cts dispersed parti culate material, forms a core on which organisms can grow , and assists in th e generation of sludges w ith good settling and dewateri ng characteristics.

Odours are ve ry rapidly taken up by ZELflocc, heavy metals are removed even w hen at low concentration in solution, a nd met al sa lt r eq uir e m e nt s for phosphorus precipitation are redu ced.

Wh en applied during plant sta rt- up foaming is minimal, and effective removal of suspended solids and oxygen demand occurs even before tru e biological floe s have had time to form.

Some benefits of ZELflocc can be observed immediately after do sin g commences, indicating the rapid physicoc h e mi cal m ec hani sm s, but major improvements in settleability frequ ently take some weeks to become apparent, and it is obvious that biological changes ha ve then occurred within the system.

60

WATER MARCH 2002

Metals and phosphorus

Proper sizing of the ZELflocc powder is important as it has been fo und that poor results are obtained if the material is too coarse . T he powder is intimately mixed into the biomass of the treatment system upstream of the reactor, within the reactor, or in th e sludge return stream. It may be added in a dry form or as a slurry, and while steady dosi ng is preferred this is not critical for most applications.

The ZELflocc powder is not separated from the sludge prior to wasting, and continu es to provide benefi cial effects, such as odour control, easier dewatering, and suitability for co mposting and vermic ulture, during sub se qu e nt slud ge treatment and reuse .

Settleability Improvements

Many ca uses have been proposed for poor settleability of activated sludges, but at this time non e of the th eori es are ve1y satisfacto1y . Excessive filament growth has frequ entl y been associated with poor settleability, but this is not always the case, and even when it is, the va ri ety of organ isms identified, and the wide range of associated plant operating conditions , suggests that there may be several different ca uses .

After ZELflocc dosin g, bac teria grow o n the surface of th e zeolitic material and

Hea vy m etals are ve ry effec tively removed from solution by ZELflocc, even when present in solution only at ve1y low conce ntrations. Th ese metals are then bound so strongly that they are unavailable to plants grown in soils to w hi ch the sludges have been added.

Pho sphate, being anioni c, is not attra cted to the zeolite framework, but mu ch of the earlier process development ca rri ed out involved the addition of natural zeolites in conjunction w ith al uminium and iron salts being used for phosphorus precipitation It was found that equivalent phosphorus removals could be ac hi eved at about half the norm.al metal salt dosage, and that performance of the system s was less affected by interruption s to m etal salt dosing. Work to date has co nfirmed equi valent performance at a twenty to thirty percent alum redu ction , and further work in this area is proposed.

Odour

Odour is ve ry rapidly 1;emo ved under ZELflocc. Ammonium ions are known to be very effectively removed from solution by exchange onto clinoptilolite, but such a mechanism would not be effecti ve for anions such as sulfide, so it appears likely that adsorption is also a signifi ca nt mechanism. Removal appears particularly

WASTEWATER

effective with odours arising from sludge processing, but significa nt redu ctions have also been observed w here sulfide wo uld be expected to be significant, such as in one reactor where partial ae ration fai lure resulted in the contents having a very septi c appea rance, but little odour.

Sludges

Sludges from processes operated under ZELflo cc dewater readily, and have an op en stru cture suited to composting and vermiculture. In one sludge chickening applica tion a polym er reduction of nventy five percent was noted after ZELflocc dosing was introdu ced to the oxidation ditch generating the sludge.

Odour removal benefits ob tained from ZELflo cc dosing of acti va ted sludge extend throu gh subsequ ent sludge handling and reuse stages, and are particularly apparent w here sludges m ay have to be stored or reused w ithout adequate stabilisation.

Australian experience General

A major difference between ea rlier pro cesses and ZELflo cc is that earlier processes limited nitrifi catio n in ac tivated sludge in order to conserve nutrients and energy, with excess ammonia being remo ved in a subsequ ent ion exchange fi lter. ZELflocc, o n th e other hand, has so far concentrated on improving the performance and capacity of existing plants with ni.inimal capital expenditure, and hence improved nitrifica tion and denitrification within activated sludge has been ac tively promoted .

As already indicated, ZELflo cc has been applied in Australia to a wide range of co nditions, with plants varying in flo w from 40 kL/ d to over 50 ML/ d, sludge ages from around 1. 5 days to in excess of 40 days, and along the east coast of Australia fro m near Townsville in the north to M elbourn e in the south.

Plant configurations ha ve included oxidation ditches, both co ntinuous flow and interni.ittent decant, conventional cellular configurations, and packa ge plants. The process has been applied with both diffused air and m echanical surface aeration (both verti cal axis and brush types) .

Slu dge treatment systems ha ve included aerobic and anaerobic digestion, lagoo1i.ing, drying beds, sludge thickening, and slu dge dewatering.

The first controlled trial w ith ZELflocc in Australia commenced in 1995.Since then long-term experience (3-4 years continuous operation) has been obtained at three sites (Oxley C reek Stages 3&4, M edowie and Bolwarra), with th e latter two now decomni.issioned (when the load on these severely overloaded plants was transferred to larger regional plants) . Oxley C reek 3&4, w hich previously suffered continually from settleability problem s, has rarely had stirred SVIs greater than 100 ml/gm since ZELflocc dosing was instituted in April 1998, and no w usually has stirred SVIs around 50 ml /gm .

More recently, improvements in dewaterabili ty provided by ZELflocc are being quantified. While ZELflo cc itself adds to the weight of the sludge, laboratory testing indica tes that this should more than be compensated for by improved remo val of wa ter, and this is being confirmed by fie ld experience. Even without the normally expected settleability having ye t been obtained at Gibson Island (and it is the biological changes causing this improvement wli.ich are thought p1ima1iJy to increase dewaterability) improvem ents in dewa terability are already nearly compensating for the weight of ZELflocc added, w li.ile at Bombo dewa tered sludge solids contents almost doubled at a time w hen ve ry good se ttleability was obtained .

Specific Examples Medowie WWTW (Hunter Water)

This was one of the earliest properly-controlled trials of

INNOVATION

ZELflocc in Australia, and resul ts were so successfu l that the proj ect was commercialised and continued for about 3.5 years until this ve ry overloaded intennittent decant plant was decommissioned on transfer of the load to a larger region al plant.

Prio r to ZELflocc part of the inflow had to be dive rted to aerated po nds even in dty w eather, but w ith improve m ents to settleability brought about by ZELflocc th e settlin g period before deca nt was reduced from 60 minutes to 30, the cycle time redu ced from 4 hours to 2, and bypassing becam e unnecessaty except under significa nt wet w eather conditions.

With time, loading on this 2,000 person plant increased from 3,500 to around 5,500 so that, even with an unstirred SVI around 50 ml / gm and a cycle time of 2 hours, the plant eventually had barely enough hydraulic capacity to handle dry weather flows. Aerators then had to be turned off for 2-3 days at a time in we t w eather to avoid solids loss, and hence w ere able to resume good treatment again as soon as inflow dropp ed off.

Very good settleability was maintained under very low dissolved oxygen, and was in fact initially obtained at a time when

WASTEWATER

ae rato r fa ilure res ulted in a sep tic appearance to the mixed liquor (but w ith ve1y little odo ur du e to the presence of ZELflo cc) .

Oxley Creek WWTW (Brisbane Wa ter)

Oxley C reek WWT W is a co nventio nal activa ted sludge plant with a no minal design capacity of 185,000 ep .

D esigned fo r carbonaceous B OD removal o nly, concern regarding enviro nmental effects du e to nitrogen in the effiu ent led to partial fundin g und er the Qu eensland Government' AW T T schem e to dem o nstrate on half of the plant that full nitrification co uld be obtained in w inter without modification to the civil structure.

This was successfully ac hieved du e to an increase in sludge age enabl ed by settleability improve ments brought abo ut

by ZELflocc, as is repo rted in a paper by Barr, Balthes & Cooksey, (1999) ZELflocc was then adopted commercially for this half of the plant, and has now been operating well for more than 3 .5 yea rs.

More recently, ZELflocc has also been adopted for the second half of the w orks at O xley Cr ee k to enab le progressive modification of the w orks to incorporate anoxic zones and recycle for denitrification. To do this, the sludge age

Au strali a Our business is providing the scientific basis for the sustainable management and development of atmospheric, marine, and freshwater systems and associated resources .

of the whole works has been reduced to the level used befor e implem entation of ZELflocc (thus temporarily sacrific ing impro ve d nitrifi ca tion ), so that the superior settleability provided by ZELflocc can be used to provide sufficient capa city during modifi cations to pass the w hole flow thro ugh three-quarters of the works.

Bomba WWTW (Sydney Water)

Bomba WWTW is a 12,000 p erson intermittent decant plant which utilises a lagoo n fo r storage of sludge betwee n peri odi c visits by m obile dewaterin g equipment. Under ZELflocc ve ty good settleability has at times been obtained at Bomba, but this has not been the case continually . Difficulties were initially exp e ri e n ce d ac hi ev in g th e d es ir ed ZELflocc content in the sludge, and once very good settleability was obtained dose rates we re redu ced to determine the extent to which this affected pe1f ormance.

Following resto ratio n of the dose rate to desired levels m ech ani ca l probl e ms hindered consistent operation of the plant, but at the time of wri ting steady impro ve m ent was again being achieved.

The effect of ZELflocc on the sludge lagoon and dewatering at Bomba has been at least as mar ked as its effect on

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WATER MARCH 2002

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I INNOVATION

settl eability. For the p eriod of best settleability (prior to testing the effect of dose rate on settleability) no solids ove rflow from the lagoon was experienced for the full six months between desludgings , despite this otherwise being common. Cake solids w ere also measured at around 20%, whereas these had previously been around 10-11 %.

With the reduction in ZELflocc dose, solids ca rryo ver again bega n to occur before desludging, and the solids content of the cake dropped back to abo ut 16%.

It sho uld also be noted that w hile there was a deterioration in settleability at the redu ced dose rate, this w as still considerabl y better than pnor to ZELflocc, and wa s ge n e rally adeq u ate for operation of the plant (i. e. MLSS concentra tion did not have to be restricted, and solids entrainment in the eillu ent did not occur) .

Gibson Island & Fairfield WWTW (Brisbane Water)

WASTEWATER

to , and cost savings for, municipal wastewater treatment systems. It should be emphasised , howeve r, that these advantages are not limited to municipal systems, being eq ually applicable to many industrial situations.

From an environmental point of view ZELflocc offers a low cost and easy to impleme nt m ea ns of pro viding enhanced environmental protec tion , greater system capacity, redu ced odour both during trea tment and subsequent sludge dewatering and reuse, protection of the receiving water from heavy metals, redu ced metal salt additions for phosphorus precipitation, and desira ble characteristics for sludge re use.

It is also considered advantageous that, while ZELflocc ma y involve addition of other materials for specific purposes, these benefits are generally obtained using o nly a modified natural mineral rather than a synthesised produ ct.

References Barr K G, BaIth es C A, Cooksey P A (1999) Th e Z elflocc Proc . Water, 26 . No 6.

November pp 21-25

The Author Leon Charuckyj is T echnical D irector ofZeolite Australia Ltd., Tel 61-3 9699 4599 , email Iczel@ ozemail. com. au

W:EDEE:IC!J I }jf~J.!JJ:Jj

~\}i,

Like Oxley C reek, Gibson Island and Fairfield are bo th op era ted by Brisbane Water.

While not as yet performing as well as Oxley Creek, performance at these plants is interesting because they demonstrate a wide range of operating conditions.

Gibson Island is a large extended aeration plant, sludge wasted to a picket fence thickener, and then directly to dewatering, w hile Fairfield is a small, high rate plant (sludge age less than 3 days), with co-set tl ed slud ge go ing to anaerobic digestion.

A s a lr eady mentioned , improved dew a tera b ili ty at Gibson Island is already nearly compensating for the weight added by ZELflocc, altho ugh settleability improvements at this stage are still less than are exp ected to be achieved.

ZELflocc has been utilised at Fairfield for a considerable period of time but pe1formance has been varied du e to solids carryover from primary sedimentatio n.This is thought to have been due to difficulties in controlling activated sludge wastage to the primary sedimentation tank. A new waste activated sludge thickening system is exp ected to overcome these difficulties .

Conclusions It can be seen from the above that ZELflocc offers exciting possibilities for improvements WATER MARCH 2002

63

INNOVATION:

WASTEWA.TER

THE CDS STORY: CONTINUOUS INNOVATION R A Jago, A Davey Continuous Defl ect ive Separation (CDS) is a screening technology capable of removing solids from liquid streams at high.flows by exploiting indirect screening to achieve genuine non-blocking peiformance.

lice'?ices in 5 co untries o n a fee plus royalty basis.

The Technology

The Beginnings Not many people have the privilege of d ec iding to inve nt so m e thing an d succeeding at it, but that's exactly how the CDS technology cam e about. In 1992, two innovative drainage contra ctors pondered how to construct a screening device that wo uld remo ve leaves, litter and other debris from stmmwater without the probl em th at all su ch devices experience - blocking of the screen and consequ ent bypass of the device. As the histo1y of CDS, or Continuous D eflective Separation shows, they succeeded spectacularly .

After much experimentation, success was achieved and a device developed that co uld operate co ntinuou sly w ithout blocking. Patent protection was immediately sought and about a year later construction of 2 units was commenced to protect a popular beach on the Mornington Peninsula from the litter generated by a nearby shopping centre.

Agreement for the installation of a large test unit was reach ed w ith Melbourne Water shortly afterwards . Significant financial backing follo wed.

In 1994 a company - now called CDS Technologies - w as incorporated to exploit the technology. In 1995 this company had 5 employees and had sold only a few units. Today it has around 90 employees in 3 countries and by the close of 2001 there were just on 950 units installed in 5 countries .

One of the first tasks was to understand what had been invented. The company turned to the universities and to CSIRO to h elp define the technology more fully so that it could be exploited commercially and supported properly in the field. Later, an in- house R&D team was formed to develop this understanding still furth er.

Quite early in its histo1y, CDS was the recipient of a DIST grant for research; 64

WATER MARCH 2002

Figure 1. Schematic view of the CDS unit showing the basic components

more recently, it received a large R &D Start Grant that over time led to the development of two new products based on the technology .

These resources helped enormously in establishing the technological base for the conu11ercial success that the company now enjoys as it learned how to adapt the basic technology to different applications. The first product was an innovative screening device for stormwater, which provided a " bread & butter" line to fund further expansion. Other, more sophisticated, produ cts fo llowed.

Listing on th e Au stralian Stock Exchange was initiated in 1996, large numbers of units were installed over the next 2-3 years at the Homebush Bay site of the 2000 O lympics, and a subsidiary company was established in the USA. This company now has 9 offices and is fast approaching finan cial independen ce .

R evenues from this operation will soon dwarf those of the Australian parent.

O ver the following 3 yea r period the co mp any received 6 awa rds for its technology, commercialisa tion efforts and its contribution to the environment.

In 2000, it purchased a controlling interest in Copa Limited, a UK company supplying to the European water and w astewater m arket. At present CDS is pressing forwa rd w ith li cen sing its technology internationally and has granted

At its simplest, the technology m ay be represented by a cylindrical tank containing a submerged m esh screen into which the influ ent is introdu ced (Figure 1) tangentially. T h e screen itself contains apertures that are partially shielded against the flo w, such that solids contained in the flo w do not actually " see" the apertures of the screen but are defl ected away from them as they approac h. D epending on their density, these trapped solids either float on the surface or sink into the sump w here they collect awaiting later removal.

At the sam e time, the wa ter in which th e solids are entrained passes throu gh the screen co make way for incoming fluid and flo ws away in the opposite direc tion to the circulation inside the screen . In this way an effective separatio n betwee n solids and the liquid is ac hieve d, with the solids becoming concentrated inside the separator. A major advantage over other solid/ liquid separation systems is that the operation is entirely non-mechani cal.

The difference between this separation m ethod and conventional screening lies in the indirect nature of the screening process, whereby the flo w is dissipated in a controlled way through the screen and blocking avoided. In Figure 2 both conventional " direct" screening and the patented CDS system of indirect screening are illustrated.

The Products This simple te c hnolo gy ca n b e configured as numerous produ cts for specific applications, but the sam e basic principles still apply. To date, the largest application h as been that originally targeted by the inventors ., the separation of gross pollutants from stormwa ter.

Other products are gaining in importance, however, and separators have now been sold for several important industrial appli cation s, w hil e n ew ones a re constantly being evaluated.

INNOVATION

WASTEWATER

for best performance a fin e expanded metal mesh screen, Th e d es irabilit y of plas tic co ated to minimise removing unsightly m an... attac hment of oil and grease, made solids from stormwa ter was chosen . before it is discharged into Solids handling is also receiving w aters may seem much m ore d em anding than obvious, but there are many fo r stormw ater as the solids other pollutants that affect the acc umul a t e r apidl y a nd environment adve rsely that cannot be stored for any can also be removed by the length aof time . For chis C DS Gross Pollutant Trap. It is no w well kno w n that reason, the solids stream must Figure 2. Schematic illustrating "direct" (left) and "ind irect " be rem oved on an appro xivegetative material such as leaf screen ing (right) m a cely h o urly b as is and litte r an d grass clippin gs and 30% for total phospho ru s, w ith returned to the sewer. These, and other deplete the dissolved oxygen in receiving nitrogen remo val showing variability, d esi g n modifi c ations, e n abl e d the w aters while silts and sediments are implidepending on the form present. c ontinuou s d e fl ec tion se pa ra tion ca ted in the dieback of sea grasses and technology to be successfully adapted to transport of heavy metals. M an- made litter Sewage Solids Sepa rator use with sewage. affects fish , seabirds and other species The same technology w as next applied throu gh inges tion .

Initially, two test uni ts, one in the USA to produce a screening device - the Gross and one in Australia, were installed in the Owners and users of C DS GPTs Solids Separato r (GSS) - to remove gross inlet headworks of sewage treatment continu e to be am azed at the amount of solids from ove rfl owing sewers at high m aterials ac tu ally trapp ed and removed plants and evaluated over a tw o yea r flow rates . This device splits the influ ent from stormwa ter. The company recently perio d , screening raw sewage down to into a stream contai ning all solids large r conducted a review of its commercial 1mm. Pilot plant res ults show that the than lnrn1 (1% of the inflow), and a removes all particles down to 1mm stormwater device maintenance operation GSS screened discharge fr ee of all visible solids and almost all grits and settleable solids in Sydney, where data from 334 cleanouts (the remainder). dow n to lO0Âľm.

Rise rates in the unit are of operating units over a 3 year period was Inst all ation of th e Gro ss Solid s up to 285 1113 / 1112 / h . For installations , analysed. It was found that the average Separator (GSS) is show n in Fig. 3, w here, operatio nal histories ~xceeding 3 years are pollutant load captured by units ra nged fo r a Sanitary Sewer O verflow (SSO) the fro m 0.64-1. 36 m 3/ ha/ y r, w ith the now available fo r units at several sites in dive rsion chamber is built into the Australia and the USA. T w o of these have sm aller units having the largest specific connection between the sewer and the a design capacity of ca. 11113 /s and have capture, probably ow ing to their instalstom1water line, or for a Combined Sewer lation in small cat chme nts such as op erated successfully w ithout blinding of O ve rflo w (CSO) into the o ve rflo w the screen, even under conditi o ns w here shopping centres w hich have highly discharge line. The screen ed flow is the design capacity w as exceeded . co nc ent ra ted pollutant lo ads. These discharged to stormw ater or receiving capture fi gures are well in excess of those T he US unit, installed o n a C SO in water as the case may be, and th e purge found by other workers (typically 0.23K e ntu ck y, has b ee n ind epe nd ently (containing all the solids) 1s stream 0.40 m 3 / ha / yr) using annualised rainfall monitored by the en gineers responsible returned to the sewer or diverted to data (Brisbane C ity Council, 1999 : for its installation (O'Brien & Gere, 2000) storage .

Allison et al 1998) . has returned results for TSS rem oval and T he fib ro us nature of sewage was a A recurrent observation is that particles over several m o nitored events fr om 22seri o us problem encountered in the 53%. Significant but variable removal rates much smaller than the screen apertures are adaptation of this technology to sewage, were also demonstrated for TS (10-37%), routinely captured. One major authori ty owing to "stapling" of the screens by th e TP (8-22%) and BOD (6-36%). It is clear in Qu eensland conducted its own detailed fibres . The screens used fo r sto rmwa ter that the rem oval effici encies vary w idely screening were fo und to staple badly, and evaluation of the GPTs it had installed. depending o n the natu re of the Samplin g o f th e sump sewage, the ca tchment and rainfa ll. contents o f the C DS GPT E ve n so , the improve ment in these over 3 separate occasion s water quality param eters is impressive showed that on ave rage for a screening device design ed 28% of the load had a primarily fo r aesthetic cleanup , and p a rticl e si ze <7 5Âľm . represents an unexpected bo nus in (Brisban e C ity Council , sew er ove rflow m anagem ent.

1999).

The same engineers also evaluated But above and beyond the res ults of applying UV disinfec tion directly to the screened the capture o f co nventional g r oss pollut a nt s a nd fluid em e rging fr 5> m th e GSS sediments, other advantages installed on the Kentucky C SO. ha ve b ee n not e d. An They found a 2-3 log reduction in independent study (Walker fa ecal coliforms was achievable even et al 1999) of an installed under first flu sh conditions w hen the GPT in M elbourne reported TSS was 500ppm. H owever, it is mean removal efficiencies of Figure 3. Install ation of the Gross Solids Separator where unlikely that better results than these w ill be o btained w itho ut sewer and drainage systems are separated approxi mately 70% for TSS

Stormwater GPT

..

66

WATER MARC H 2002

INNOVATION:

Raw Sewage

WASTEWATER

Mixing & Maturation

Figure 4. Process flowchart for the CDS Fine So lids Separat ion Process

removing the bulk of the suspended solids, for which the Fine Solids Separator 1s required.

Fine Solids Separator (FSS)

ac hieve an effective increase in sewer capacity at relatively low capital cost.

Results of a trial of the FSS extending ove r a 2-month period showed significant improvements in several wate r quality parameters. The results, which are listed in Table 1, are taken from an independent report issued by Barwon W ater (Teng and Williams 2001 ).

It can be seen from the table that large redu ctions have been ac hieved in almost all p aram e ters m eas ured , with th e exception of dissolved matter. T h e turbidity and TSS results taken over an extended period show that consistent solids removal can be achieved despite significant va riations in influ ent conditions.

The removal of faecal matter as particulates resulted in a 2-log reduction in FC. Tests on a side stream of th e efilu ent showed that a further 4-log reduction could be ac hieved by UV disinfection, reducing the colif01m count to an average of 16 orgs/ l00ml and demonstrating that satisfactory disinfection of the efiluent is possible under appropriate conditions .

The removal of fin e particulate solids has also produced a lowering of the BOD, with the soluble fraction being unaffected by the process, although easily reduced by later exposure of the efil uent to air.

high flows by exploiting indirect screening to achieve genuine non-blo c kin g pe1formance. Its utilisation in Clear th e re mediation of wet Effluent weather flows, in particular stormwater, has been extensively monito red and has b een shown to be highly effective in limiting pollution of the environment.

Extension of the basic technology to other products is facilitating the manage m ent of more difficult waste streams , incl uding sewage. Physical separators based on the CDS principle can m anage th e fibrous m aterials present in sewage and are findin g application in the aest h eti c cleanup of sewage sp ills.

D evelopment of a hybrid, physicochernical treatment process also based on the technology is ac hieving large reductions of several pollutants from raw sewage at high rates . Applica tion of this process to other waste streams is an exciting prospect that is currently being explored .

The addition of alum to the efiluent from the GSS enco urages coagulation of the fin e solids into flo es so that they can be captured by a seco nd separator.

Indirect screening facilitates capture, as the coagulated solids tend to blind the screen much less than they would do with conve ntional direct screening.

T his simple concept is the basis of a high rate process for the remo val of fine solids from waste streams. The process has been configured as a mobile plant and References evaluated for sewage trea tment, where it 1. SQ!Ds Monitoring Program Stage 2, Water can clarify raw sewage in just over 2 & Environment City Design , Brisbane C ity minutes at the design flo w rate (35 1/s).

Co uncil, August 1999.

The loading rates in the unit are in excess 2. Allison R. A. et al. , From Roads to Ri vers: of 110m3/ m 2h , w hich contras ts sharply Gross Pollutant Removal from Urban wi th 2m3 / m2 h for settling flo cculated Waterways, Cooperative R esearch Centre for sewage . To ac hieve performance of a Catchment H ydrology, R epo rt 98/ 6, May sedim entation tank comparable with the 1998.

FSS wo uld therefore require a unit w ith 3. Walker T. A., AJljson R. A., Wong T. H . F. 55 times the surface area. & Wootton R. M ., Remova l of Suspended In prac tice, screened raw sewage from Solids and Associated Pollutants by a CDS the GSS is dosed with alum, followed by Gross Pollutant Trap, Coo perative R esea rch a polymer to increase floe strength. After Centre for Catchment H ydrology, Report addition of a sm all amount of air, the 99/2, Febru ary 1999.

4. O'Brien & Gere, Prelil/li11ary Eveut Eval11atio11 stream is passed through a static mixe r to Sw11111ary Reports, CSO 108 , Louisville, ac hieve vigorous mixing. Maturation Kentucky, USA, 2000. takes place in line and the resultant flo es 5. Jago R. A., Davey A. and Li H. , A High Rate Concluding Remarks screened out in a sp ecially adapted Clarifier for Load Levelling in Sewerage Systel/ls, separator. The process, which reaches Continuous D eflective Separation Proceerungs ofIWA World Water Congress, steady state within 3 minutes, is shown (CDS) is a screening technology capable M elbo urne, 2002. schematically in Fig. 4. of removi ng solids from liquid strea ms at 6. Teng M. L. and Williams P. G., Trial of CDS T h e FSS sys t e m was Fine Solids Separa tion System at rece ntly eva lu ated Qago , Ocean. Grove, Victoria, Barwon Davey and Li, 2002) as a R egion Water Authority report, Table 1 . Water quality data from fie ld t rial of FSS unit sewerage m a nag e ment Geelong, Victo ria, 2001. technique by Barwon Region Parameter Units Influent Effluent Red 'n. % The Authors W ater Authority (Geelong, Turbidity NTU 131 8 94 Victoria). The region has a Dr Richard Jago I S TSS 137 19 mg/I 86 large influ x of tourists in Business D ave lopm e nt 151 B0D 5 48 mg/I 68 summer and the local STPs are Manager, Alex Davey I S COD 365 166 mg/I 55 heavily loaded at this time.

Senior Process Engineer for The ability to clarify sewage FC CFU/ 100m l 5.8 X 10 6 62 X 103 98.9 CDS Technologies, Tel 61from the system at times of TP 9.5 1 .2 mg/IP 87 7 8 0 0, e mai l : 3-9781 peak flow and return it to the 40 Oi l/Grease 10 75 mg/I ri c h ardj @c dste c h. co m. au, sewer at times of low flo w NH4-N mg/I NH4-N 46 38 17 wo uld enable this authority to website www.cdstech.com.au 68

WATER MA RCH 2 0 02

INNOVATION:

WASTEWATER

THE AQUABLADE DIFFUSER G Johnston, P Fullwood B1iilding on more than a quarter of a cent11ry of experience in aeration equipment and technology, A11stralian firm AQUATEC-MAXCON has developed a revolutionary new membrane type, fine b11bble air diff11ser that is providing exceptional performance. The AquaBlade has a 11niq11e elongated profile that has been carefi,lly engineered to promote optimttm oxygen transfer while ens11ring a system offering s11bstantial economic advantages.

Aquablades being installed in a tank

Development of the AquaBlade commenced in 1996 as part of an extensive R&D program. It has now been in service in full-scale trial installations since 1997.

Substantial research was directed to the membrane, resulting in a unique silicone membrane that offers substantial operational benefits when compared w ith traditional EPDM membranes. The proprietary silicone material contains no plasticiser or carbon black, w hich are known to lead to accelerated membrane fouling, but retains excellent tear resistance and bubble formation characteristics.

The AquaBlade incorporates a number of other features such as do uble seals for additional security against leakage and dual check valves to prevent ingress of liquid back into the pipework in the unlikely event of a damaged membrane . Each diffuser is also factory tested to ensu re proper operation and bubble pattern before packaging ensuring that all diffusers dispatched from the factory are defect free .

The diffuser shape ha s been designed to exert minimum uplift, reducing loads on pip ework and air distribution pipework within the tank. This can result in considerable cost savings, as the length of pipe and number of associated supports is in some instances less than a third of that reguired for traditional disc diffuser sys tems . Speed of installation is also increased as the diffuser bolts directly onto the pipe via an extremely strong bolted connection with an 'O' ring seal, eliminating any adhesive joints.

It is able to mount on either plastic or metal pip ework enabling both fixed to the floor and removable 70

WATER MARCH 2002

diffuser grids. These features result in a system with low capital cost.

The AquaBlade has demonstrated exceptionally hi gh oxyge n transfer efficiency. Recent NATA certified testing for a client demonstrated oxygen transfer efficiencies exceeding 30gO 2/ Nm3 .m, demonstrating the world leading performance of the diffuser and the benefits of the extensive local development program.

As aeration is the largest source of power consumption in wastewater treatment, the benefits of our research translates into substantial operating savings for end users.

Test tank As part of the AquaBlade program, Aquatec- Maxcon developed an in-house fac ility for works testing of diffused air equipment; believed to be the o nly one in Australasia . The unique full scale facility enables demonstration of the performance

of the equipment's oxygen transfer capability at the works before installation, offering cli en ts seve ral adva ntages, including: • Better control of aeration test pro cedures produces more acc urate results that can be witnessed by the client and NAT A certified in accordance wi th AS CE Standard (1984).

• R eduction in contrac t time, as p erfor m ance proving can be done before installation .

• Lower costs du e to reduced chemical requirements and need to build tempora1y bailles, etc., for test purposes .

• Reduced clean water usage and associated costs to the client.

Air flow, back pressure and temperature are measured and the identical airflow/ diffuser and applied to replicate field conditions. Airflow is adjustable using a variable frequency drive on the positive displacement blower. Diffuser headers are placed at id entical spacing to the field installatio n and an end baille adjusted to simulate the correct tank size. Diffusers on each header are installed at identical floor height, immersion and spacing of those in the actual installatio n. Our test tank has a volume of 160cu.m (7m L x 3.8mW x 6. 15m H ), ensuring realistic results.

T he AquaBlade now has over 25 full scale installations for major customers in Australasia including United Water's Bolivar plant in Adelaide, Brisbane Water plants at Oxley Creek, Gibson Island and Waco! and the North Shore plant in Auckland, amo ng others . Importantly, almost half the installations are for repeat customers, testimony to their satisfaction and the reliability of this revolutionaiy diffuser

,:;y,:;s..e.m.

The Author Greg Johnston is M anaging Director of Aquatec-Maxcon; Peter Fulwood is Diffused Air Product M anage r , E m ail: aquateci@gil. com.au, Web: www.aquatecmaxcon. com.a u

INNOVATION:

WASTEWATER

BENEFICIAL REUSE IN ACTION J McCarthy Millions of worms

The Australian company, Vermitech, has taken the oldest recycling technology on earth and applied the sciences of microbiology, entomology, engineering and finally agronomics to develop a s11ccessf11l f11ll-scale process converting sewage sfodge into a valuable agricultural product.

Sludge to disposal M ost was tewater engineers w ill recall, until recently, that the sludge from wastewater treatment was either stockpiled , landfilled, or simply Redland Vermitech Facility disp osed of via ocean o utfall. T he design drawings fo r new treatment facilities o r sch em es w ould often have an The Need for regulation arrow down in the corner saying "sludge R egulation is vital to protec t Public to disposal" . With the efforts of Industry H ealth and to ensure that long-term and R egulators, however, the arrow now effects of such recycling are not detrinow points in a better direction nam ely m ental. R egulators here and abroad have "Biosolids to B en eficial R e-U se" . This risen to the challenge of producing a recognises the role that this ma te rial can beneficial, sustainable and safe re-use play in achieving better environmental indu stry w ith th e produ c tion of outcomes by addressing a need understood clearly by fa rmers and other m embers of Guidelines and R egulations gove rning use . In co-operation w ith this, biosolids the agricultural community . producers (such as large utilities), consulT hat n eed is represented by soil degradation - brought about by prolonged tants and technology companies have use of ino rganic fertilizers and the promoted and researched best practice requirem ents for constantly improving solutions. crops yields. These pressures have begun A portfolio of options to fo cus attention on soil health and the need for organic replenishment of those Most sludge produ cers no w have soils. access to a "Biosolids Strategy" . Although

CASE STUDY Researcher: Dr Peter Stephens, Queensland Department of Primary Industries

a) "worm casts at 8 tonnes/ha resulted in a carrot crop yielding 6.3 tonnes/ha more first class carrots than an untreated area. This provided an additional market profit of $2340/ ha, after allowing for the cost of the worm cast produ ct" b) Suppression of Club Root in Broccoli - The soil mass had previously been infected with 10 4 - 10 6 spores per gram of Plasmodiaphora brassicae. R esults: 3 out of 4 BioVerm appli ca tions "resulted in a significant decrease in the number of clubs per root system and a significant increase in root w eight."

72

WATER MARCH 2002

direct re-use is often a principal obj ective, prudent risk assessm ent dictates that one or more beneficial re-use o utlets might come under pressure as a result of economic, environmental or regulatory pressures . This has give n rise to the concept of a "beneficial re-use portfolio" in w hich producers seek out and maintain a suite of re- use o ptions, th ereby providing fl exibility and a level of comfo rt.

C on se qu e ntl y, a di vers it y o f technologies and approac hes have gained interest, enriching the variety of options available to the industry .

The follo w ing article describ es a relatively new example of one such technology and a solution that personifies benefhial re-use in action. This example looks at the technology used, the outcomes achieved and reviews compliance with the gove rning regulations .

T he use of w orms to process organic matter (verrniculture) is not new - the d3/namic involved has been an inherent fun ction of N ature itself for millions of yea rs.

What is new is that an Australian company has been able to demonstrate, over 4 years of operations, the successful application of vermiculture to biosolids on a large scale.

At Vermitech 's R edland Bay fac ility, som e 50,000 tonnes of biosolids from a variety of sewage t rea tm e nt pl a nts h ave b ee n processed, converted into an o rganic fertilizer, and sold into agricultural m arkets in the las t 4 years

The Vermitech solution Vermitech utilises large scale vermic ult u r e h o u se d in a se ri es o f continu o us- flo w r'aised cages (in a controlled environment) to process over 50 tonnes per day of w astewater treatment sludges, feedlot was tes and green was te, as described by Kom arovski (2000) .

In itself this is unique - but only half th e sto ry .

The real "solution" is fo cussed on produ cing a valuable product rather than treating a was te. This has been a funda m ental shift in approach. T he critical elements in this m ethod (and those that differentiate it fr om others) are the systems of quali ty and process control w hich lead to a robust and replicable outcome from a variety ofbiosolids input qualities and types .

Vermitech believes it has taken the next step for biosolids by fo cusing on the end use and the end user (often farmers).

There can be no greater testimony to a recycling business than a discerning end customer, w illing to pay for a quality end product - or in Vermitech's case, having a shrewd "Aussie" fa rmer ring up and place a rep eat o rder fo r Bio Verm.

The End Product: BioVerm beneficial re-use with a financial return The end product of the Vermitech solution is called "Bio Verm", a vermicompost material w hich retains high levels of ben efi cial microbial activity . The

INNOVATION:

presen ce of aerobic bacteria and fun gi, including mycorhizal fun gi has been shown by many researchers (and ve rified

by Vermi tech field trials) to improve uptake and retention of nutrients (natural or chemical) by plants as well as improving the natural ability of soils to suppress plant and root diseases. Sustained observa tions of crop yield increases, plant disease suppression and reduction of inorganic fe rtiliser require m e nt ha ve en abl ed Vermitech co achieve a position in w hich the product is sold at commercial valu es into the professional growing industry, current examples being in fruit, vegetable, turf, sugar cane, viticulture, and pas toral applications.

M arket development has been found ed on three fundamental fac tors: â&#x20AC;˘ Research - as w ith any n ew products, fund am ental and field trial research is essential to understand the pe1formance of the product, and prove economic benefit. â&#x20AC;˘ Quality Control - a produ ct must be consistent in nature and p erformance in order to command premium pricing and rep eat sales . For this reason, Quality Assurance systems (in Vermitech 's case HACCP) are in place at the treatment facilities . â&#x20AC;˘ Market Support - Appropriate application is vital to success with organic m aterials. It has proved essential to m aintain a support team of qualified agronomists to ensure that th e m essages about the product are adequately delivered, and grower feedback consolida_ced.

Regulations in Action ,{

-

T he Vermitech fa cility at R edland o p e ra t es und er Li c.e n ce fr o m th e Queensland EPA. T his Licence describes the ac tivity as "soil conditio ner manufac. curing" in recognition of the activities being undertaken.

T he Licence conditio ns owe their o rigins to the maj or Australian regulati on on the subj ect, the NSW EPA Guidelines.

Firstly, the technology must redu ce pathogens to the very low levels associated w ith Grade A stabilizatio n status. All produ cts must be tested to ensure confo rmi ty.

Secondly, co ntaminant levels must be monj tored and assessed as th.is determines the end- use opportuniti es. Application controls ensure that soils are tested befor e applica tion of Bio Verm and that physical location and application details are tracked and recorded in V ermitech 's daca base to ensure an audit trail exists.

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CASE STUDY Tomato Field Trial: McIntosh Farms, Lockyer Valley, QLD

Harvested fruit was professionally collated and graded to Coles Supermarkets standards. Observations showed improvements in both yield and quality of fruit .

BloVerm application

NII

7.5 tjha

Change

Yield (kg)

19.3

23.7

Up 23 .1%

Marketable

15.6

21.2

Up 35.7%

3.6

2.5

Down 30.9%

Yield (No. of fruit)

313

319

Marketable

183

228

Up 24.6%

85.4

93.1

Up 8.9%

Waste

Avg weight (g)

In addition, there was an improvement in the number and frequency of higher grade fruit per 100 harvested cases .

BloVerm application

7.5 tjha

Change

36%

30%

Up 4 .6%

27%

22%

Up 4.1%

Grade C (65-70mm) $20 per case

23%

27%

Up 47.6%

Grade D (70-80mm) $20 per case

14%

21%

Up 74.1%

Grade A (50-60mm) $13 per case Grade B (60-65mm) $17 per case

NII

For every 100 cases of fruit produced under the standard fertiliser programme the standard return based on actual fruits harvested was $1671.10.

For the Bio Verm treated plots the return was an equivalent 130.5 cases in the sa me area. The return w as $2321.45 or a revenue increase of greater than 38%.

Also , du e to greater consistency of ripening, the labour cost in harvesting was reduced.

Frequently Asked Questions Interesting, but does it make economic and commercial sense?

At one level, the Vermitech solution is competitive w ith other Grade A stabilization alternatives for boiosolids. What diffe rentiates this solutio n fr om the rest is the p otential to have a solution that, in time, will be commercially self-sustaining for waste produ cers.

What about pathogen stabilisation?

T h e co mp a n y h as su ccess full y processed m ore than 50,000 tonnes of bi osolids. T he end- pro du ct is tested eve1y 100 DWT fo r a range of pathogens.

In all cases o utputs achieve standards required fo r (N SW EPA) "Gra de A Stabilised" m aterials.

How flexible is the process? What sort of input material qualities will it accept.

Th e R edland facili ty, now in its fourth yea r o f ope rati o n , rece ives substantial quantities of m aterials from a range of was tewater pro cesses . T hese include both digested and undigested inputs fro m conventio nal and BNR processes .

How reliable is it? After all, it's a biological process W orm s are extrem ely robust creatures but like any biological process, they require the correct environment and food source to thrive. Verrnitech has developed codifie d procedures, under the HACCP fram ework, to ensure optimum p rocess performance. The R edlands plant has never been offiine in over 4 years of op erations - nor has any unstabilised produ ct left the site . N o netheless, the company has a comprehensive program in place including contingency stock .

What about odour?

Biosolids fro m the va ri o us sources are immediately mixed w ith de-odou rising material at the required ratio, in a cl osed vessel. This process serves to fix th e most volatile compounds and consequently, odour at processing plants is readily co ntai n ed. T h e verm ic ulture bed s themselves generate extrem ely low odo ur as the material is subj ect to immediate stabilisation and aeration by w om1 activity.

The end- produ ct, Bio Verm, has an pleasant, earthy, humus smell and a consiste ncy similar to top soil.

INNOVATION

What happens to the pollutants in the input biosolids Of concern w h en cons id ering beneficial re-use is the presence and fa te of pollutants (s uch as pesticides and heavy metals) that are carried through the sewage treatment system and collected in the biosolids . Most organic pollutants are readily decomposed by the worms but although worms bio-accumulate small quantities of heavy metals, natural loss of wom1 biomass from the system effectively ensures that overall reduction is negligible.

Therefore metal levels are considered to be unchanged. Consequently, Vermitech undertake testing the end product for pollutant content and ensure that each batch of the Bio Verm m aterial is sold for appli ca tions only as appropriate to Regulations .

What guarantees exist for the reliability and quality of the end-product?

As the material is accepted into the facility it is batched and becomes part of a Quality Assurance System similar to any other manufacturing pro cess. Each completed batch is subject to lO0DWT analytical testing to ensure that no material leaves site without meeting th e necessary EPA standards (for h eavy metals, pathogens, and contaminants) as well as passing Vermitech's own growth potential, product maturity and moisture content criteria. All compliance data is captured in a daily database.

A "cradle to grave" audit m entality means Vermitech is able to track the material from the moment it is delivered through the complete 90 day-plus cycle of feeding, harvesting, testing and storageright down to the actual hillside or fi eld where the treated material is applied. . How long does it take to create a market for the end-product?

With the future of their properties at stake, farmers are naturally cautious abo ut new products. D eveloping demand h as benefited greatly from the employment of a Sales team of tertiaty qualified Agronomists. In addi tion, the suppo rt of industry expert advisors, third-party independent organizations such as Universities and CSIRO and of co urse , word-of-mout h , has taken Bio Verm to the point where after 2 to 3 years demand is now matched to supply.

Product sales to date exceed $1111. Of co urse, much of the hard work is now done with end users, and the question is now "how long before a major fertilizer company picks up this product ?".

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WATER MARCH 2002

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Vermitech has just answered that by signing a major Australian ferti'Jizer distributor in a deal that will see over 4,000 tonnes of bio solids-so urc ed BioVerm incorporated in a new fertilizer product.

What do fruit and vegetable retailers think about crops grown with biosolids materials?

This is a fundamental question posed by many farmers. Coles-Myer (via its Quality Assurance Division) ha ve reviewed the Vermitech process and detailed produ ct analyses and officially tated that it has no objections to farmers using the product on their crops provided that it continues to meet the standards set down by relevant Authorities. This assertio n has given several growers the confidence they n eed to apply the material, secure in the know ledge that their crops are just as marketable as ever before.

Why would anyone be interested in paying for processed biosolids?

T he end result of this process is not just som ething can be applied to ]and because it creates no further hann after processing - the enhanced biological properties of Bio Verm mean that it can ac tively rebuild the soil health , as well as e n co urag e plant growth, ea rlier emergence, and stronger root systems.

Soils have lost much of their natural fertility through continued applications of chemical fertilisers, pesticides and fungicides, and after two hundred yea rs of productivity agricultural land now struggles to sustain crops with each passing season. A few case studies of BioVerm in action are summarised in this article. Bio Verm has the advantage over direct land-use of untreated biosolids in that it is so biologically rich that most

CASE STUDY General Horticultural Case Study Portelli Farm, Maroota, NSW

Following a successful trial with seedlings, Bio Verm was spread at 2.5 tonnes / ha before cultivation. The farmer, with a lifetime of growing crops, can expertly compare the results with previous years. He witnessed an overall increase in the health of his crop, plants were stronger and growing better. The lettuce were heavier and most importantly, Sclerotinia, although still claiming the odd plant, was almost eliminated.

applications are in the 3-5 tonnes per hectare range.

Is the technology applicable to international markets?

The problem of sludge disposal and biosolid management is universal, hence so is the opportunity. A combination of sca le , economics and supportive regulatory frameworks provid e ideal markets for the Ve 1itech solu tion.

The company has conducted significant research into the USA, the UK and the EU, with initial plans being to source contracts in climatic zo nes that closely parallel its domestic experience.

The company is currently investigating the opportunity to partner other water companies in the international market and expect to have several plants operating overseas within the next several years.

Has this Technology been recognised outside of the Water Industry?

The Company was winner of the 1998 Channel 9/ Y ellow Pages Small Business of the Year Award, the 2000 BHP National Prize for Industty, the Australian Museum 2000 EÂľreka Award for Innovation, feat uring as a finalist in the Banksia Foundation Awards as well as winning a Highly Commended status at the Prime Ministers recent Environment Day awards These Awards assist not only in the marketing of this specific technology but, also continue an education process for the public at large of the merits of beneficial re-use.

What do Vermitech hope to achieve in the market place?

Rather than being the sole solution to biosolids treatment, Vermitech view theirs as complementing several other beneficial re-use technologies, designed to provide Water companies with other choices (where both a commercially and environmentally end product is the desired outcome).

How do I learn more?

By contacting Vermitech on 61 2 9261 4045 or emailing sales@vern1itech.com

References Komarowski , S. 2001 VermiCLtlture for Sewage and Water Treatment Sludges. Water 28 39-

43

The Author Jeff McCarthy is Managing Director of V ernutech .

INNOVATION:

WASTEWATER

·

MELBOURNE'S WESTERN TREATMENT PLANT Innovation and cooperation the keys to upgrade B McLean, P Scott Western Treatment Plant is the largest sewage treatment facility in Australia and one of the largest in the world, covering 10,850 hectares. It processes more than . 500 megalitres of sewage a day and was commissioned more than 100 years ago.

This paper outlines the innovative program undertaken by Melbourne Water to significantly reduce the discharge of nitrogen to the enclosed Port Phillip Bay.

Abstract M e lb o urn e Wat er's W es t e rn Treatment Plant is acknowledged as a wo rld leader in environmentally sensitive sewage treatment processes. It is one of the largest sewage treatment fa cilities in the world, and discharges treated sewage into the enclosed Port Phillip Bay, w hich is of vital economic, recreational and environmental importance to M elbourne.

T he Western Treatment Plant, located 35 kilometres south-west of M elbourne, operates in an environmentally sensitive area, declared a W etland of International Imp ortance und e r th e Ram sa r Agreement.

A four-year researc h study on the environmental health of Port Phillip Bay led to the Environment Protection Authority issuing M elbourne W ater with a new wastewater discharge licence for the plant that specified more stringent effluent quality standards. Among other specifications, nitrogen outpu t was to be reduced significantly, in part by D ecember 2001 and in total by 2005.

This pap er o utlines the innova tive program undertaken by Melbourne W ater to ac hieve the desired effluent quality. The highly successful first stage has been delivered on time and under budget, using unique engineering solutions and complying with rigorous environmental standards.

Lagoon treatment: a natural progression of microb iologica l and biologica l treatment processes

the largest in the world, covering 10,850 hectares . It processes more than 500 m egalitres of sewage a day and was commissioned more than 100 years ago.

W es t e rn Treatment Pl a nt h as develop ed from a sewage disposal farm applying all sewage flow to irrigated land to a state-of-th e-a rt lagoon-based treatment facility .

The plant treats abo ut 54 per cent of Melbourne's sewage including the major proportion of the city's industrial was te.

Effluent from the plant is discharged through four outlets into Port Phillip Bay. Treatment methods

Three parallel m ethods of wastewater treatment have been used at W es tern Treatment Plant:

Background W es tern Treatment Plant is the largest sewage treatment facility in Australia and one of 78

WATER MARCH 2002

Aerial view of Western Treatment Plant

• Lagoon treatment - 70 per cent of annual flow • Land filtration (irrigation) - 15 per cent of annual flow • Grass filtration (overland flo w) - 15 per cent of annual flo w .

Lagoon treatment operates all year round. Sewage flo w p asses through se qu e nti al ponds usin g a natural progression of microbiolo gical and biological treatment processes .

Initially, anaerobic pro cesses digest organic material to produce methane gas.

C overs are used to co ntain odo ur and capture gas, which is used for power generation. M echanical aeration is used to create aero bic conditions after the anaerobic reactor in the first pond.

After the first pond ae robic conditions are m aintained by ac tion of the w ind. Aerobic bacteria and algae fe eding on nutrients and trace elem ents develop in these ponds. T he algae and bacteria are grazed by zooplankton and protozoans , w hich are a key food source for wa terbirds. Secondary treated wastewater then flows into the bay .

Land filtration op e rates during the w armer months of O c tob e r to April , when evapo ration is high . T h e process is a repeated threewee k cycle of floodin g paddocks w ith wastewater,

INNOVATION

WASTEWATER

Port Phillip Bay Environment Study

Poten tial add itional water recycling

The Environment Improvement Project will enable up to 50 per cent of Western Treatment Plant's effluent flow to be recycled.

allowing them to dry, then openi ng the paddocks to grazing by sheep and cattle.

The treated wastewater seeps into drains before flowing to Port Phillip Bay. Grass filtration op erates during the cooler m onths of M ay to September.

Water

Wastewater that is treated to remove solids and settleable material is allowed to flow co ntinu o usly over th e soil surface and through the grass. T he treated wastewater flows into drains after five days and then into the bay .

Between 1992 and 1996, M elbourne W ater sponsored Australia 's largest scientifi c re se ar c h ins ti t u tion , th e Commonwealth Scientific and Industrial R esearch Organisation (CSIRO), to manage the $A1 2 million Port Phillip Bay Environment Study.

Although the bay was fo und to be "surprisingly healthy" by world standards, the study identified a danger to its longterm. health if nutrient loads from the Yarra River and its tributaries, storrnwater drains and Western Treatment Plant were to increase . T his wo uld result in high nutrient concentrations causing excessive plant and algal growth and eventu ally eutrophication.

The stu dy recommended a new target fo r ann ual nitrogen load to P ort Phillip Bay that represents a 1000 tonnes per year reduction from levels during the study.

Discharges from the plant contribute some 50 per cent of th e nitrogen load entering the bay, so a target reductio n of 500 tonnes per year was adopted for the plant.

With growth in nitrogen inputs to Western Treatment Plant since the study

Clean-iX Continuous Ion Exchange for Colour, TDS, Ammonia, Heavy Metal Removal & Resource Recovery

Wastewater BioTeQ Systems for BOD, COD & Nitrogen Removal BioAugmentation for "In-Sewer Treatment" of BOD, Grease and Sludge

Web Site: www.cleanteq.com

E-mail: info@cleanteq.com

WATER MARC H 2002

79

INNOVATION

p eriod , this target now amounts to an overall reduction of800 tonnes per yea r.

This nitrogen load obj ective is reflected in the plant's EPA Victoria discharge licence to be achieved by 1 Janua1y 2005, with 400 tonnes per year of the reduction required by D ecemb er 2001. This initial target has been achieved.

A number of other concentratio n targets (ammonia, biochemi cal oxygen demand , total suspended solids and vari o us toxicants) also corn.e into effect in Janua1y 2005.

WASTEWATER

red gums, but is no w part o f the M elbourne W ater sew age treatment lagoon series .

Any upgrades or construction work on the W estern Treatment Plant site co uld therefor e be undertaken only under the strictest environmental guidelines and prac tices.

]~-·

80

WATER MARCH 2002

"

,.,.,.,,.-,

:

The Environment Improvement Project

In 1998 M elbourne W ater developed the Environment Impro ve m ent Proj ect Ramsar Wetland of International for W estern Treatment Plant.

Importance The obj ectives of the proj ect are to: In 1983 the wes tern shores of Port • Red uce nitrogen discharges to Port Phillip Bay we re designated a W etland Phillip Bay of International Importance under the • Substantially reduce odo ur emissio ns R amsar C onvention . This classificatio n from the site, so that no offensive odou r includes th e w hole W estern T reatment Plant site. is detectable beyond the bo undary of the W estern Treatment Plant Many internationally significant species of wa te1fowl and migratory waders are • Eliminate raw sewage treatment on found within the area and occur in large land numbers, including thousands of w aders, • Implement effiu ent reuse on site which fl y in from Siberia to escape the • Maximise future opportuniti es for northern hemisphere winter. Lake Barrie effiu ent recycling and the other sewage treatment lagoo ns • M eet future EPA Victoria perfo1111ance are also recognised as an important standards fo r efflu ent quali ty by 1 January sa n ctu ary and drou ght refu ge fo r 2005 . wa terfow l.

Progressive enhancem ent of W estern Lake Barrie w as originally a small Treatment Plant's lagoon- based treatment sw amp with paperbark trees and a few systems was identified as the most appropriate way to meet these objectives.

The capacity and nitro ge n raw influent removal performanc e of th e (QMUd) lagoons is au gm e nted b y an activated sludge plant. This enables anaerobic pot land filtration and grass filtration to be phased o ut and a m ajor wa ter pond 1 recycling system w ill provide + pond 2 recy cl ed lagoo n efflu e nt for COO feed to (2QMUd) A/S plant summer irrigatio n. + (0.2QMUd) pond3 M e mbran e c o ve rs on all WAS (0.02QMUd) + anaerobic processes contain odour pond 4 and capture m ethane gas, which can be used for power generation.

(0.5QMLJd) al, T he first stage of these works activaled sludge plant bypass has been completed including: new activated • A 190 ML/ day activated sludge sludge plant ' - - - - -- ! - = =-' plant within a major lagoon system . pondS • T wo fo ur- hectare covers on + pond6 ana e robi c r eac t o rs w ith 2 .4 + m egawatts of power ge neration. pond7 • M ajor water recycling infras+ pond8 tru cture with delive1y to 645 hectares of land completed and + pond9 delive1y to an additional 1049 + hectares of land in progress . pond 10 Su ccessful delive ry of these treateci~effkjent proj ects has been achieved through several key innovations including: Adopted SSE Lagoon process schematic

l

t!S:··.-.:.:: ·~·~ ~

Lake Borrie

Alliance contract

An alliance co ntract approac h linked the profi t o f proj ect m anage m ent, enginee ring design and co nstru cti o n companies to time, cost and quality outcomes . This established common incentives for all team m embers und ertaking the upgrade w ork.

T he alliance approac h enco uraged all m embers to fo cus on agreed proj ect obj ectives by encouraging: • Self m anagem ent among all m embers • R esolution of issues without rigid contrac t boundari es • Open book accounting • Shared proj ect scheduling.

Many design and construction innovations we r e d e velop e d through coop eration between team m em bers.

R eviews of design and constru ction within the team w ere a key component of quality control.

WASTEWATER

Process design workshop

T he process design works hop was a key fa ctor in the success of the first lagoon proj ect. D evelopment of nitrogen removal technology on a lagoon system. on the capacity and scale ofWestern Treatment Plant is uniqu e on a wo rld scale.

The workshop concept, developed by GHD, included 33 participants bringing together treatment process experts from Australia, South Africa and the US. It ran for five and a half days at the plant.

Participants brought process concepts to the workshop and through the week, developed , refined, costed and optimised these concepts. A prefelTed process was identified on the final day .

The adopted process strategically positioned an activated sludge process in the fifth pond of the lagoon system to make hest use of the nitrogen removal capability of activated sludge technology and the secondary treatm ent capability of the lagoon. This achi eved a doubling of trea tment ca pacity and trebling in nitrogen removal capability w hile minimising capital and operating costs.

A schematic of the process is shown in the diagram on page 80.

A similar workshop approach was applied later in the design process for Value Engineering and Haza rdous Operatio ns assessn1ents .

"'Where cloes ().11 the 'WC). ter go to?"

55 East Lagoon Project T he first lagoon proj ect, an upgrade of the SSE Lagoon, was completed in March 2001 and full treatment conditions were achieved in July 200 1.

T he immense scale of the SSE Lagoon Project presented uniqu e and difficult challenges. D esign solutions were developed w hich, in many cases, were beyond the limits of conve ntional engineering practices . Engineering solutions applied in the SSE Lagoon will be used in futu re lagoo n augm entations.

Key features of the activated sludge pro cess include: • 195 m egalitres per da y (average), 285 M L/day (peak) capacity • 120 ML basin volume • Two formal anoxic and two ae rated basins • Four 45-metre diameter clarifi ers • 760 ML/day internal recycle • Twenty 132 kW floating surface aerators The key innovations in the design and constru ction included: • M aximising the use of lagoo n treatment to minimise the size of the activated sludge plant • R ecycling of effluent from Pond 4 to Pond 1 to ni.inimise aeration required on Pond 1 • D evelopment of a mooring system for large flo ating m echanical aerators which nunimised cost and risk • Use of high volume low head axial flow pumps with header tanks to ni.inimise hydraulic loss and allow use oflow pressure pipelines • Use of computer modelling to verify low speed submerged mixers, saving capital and operating costs • R ecycling of waste activated sludge which helped remove nitrogen and maximised the potential for sludge reuse • Simple but entirely automated control processes enabled the plant to run unattended.

With all the fun at bathtime , we sometimes take for granted all the practical things that make it possib le. Turn on the tap and water appears ... pull out plug ... and it magically disappears without trace , but where to?

Endress+Hauser have a lifetimes experience in answering some of these questions, balancing the needs of both industry and the environment . So whether it's a question of processing , effluent or water treatment, or accurate measurement in flow, pressure, temperature or analysis, we have most of the answers , al l you need to do is ask.

Call Endress + Hauser Internet: www.au.endress.com

Endress +Hauser The Power of Know How

[nit

~,,.,

Telephone: (02) 8877 7000, Fax (02) 8877 7099 email:

lnfo@au .endress.com

Branches: VIC (03) 9881 9366, QLD (07) 3366 9280, SA (08) 8288 0661 , WA (08) 9457 4469.

WATER MARCH 2002

81

INNOVATION

WASTEWATER

Project outcomes

Water recycling

The SSE Lagoon Project was completed on time and below proj ected cost and to date has exceeded the performance improvem ents specified by EPA Victoria . The project was completed safely and without impact on the valuable environment of the site.

Once fully implemented, the Environment Improvement Project w ill enable up to 50 per cent of the plant's effiuent flo w to be delivered to a point of supply fo r water recycling. About 20 per cent of the effiuent flo w w ill be recycled across Western Treatment Plant with additio nal recycling opportunities being pursued offsite.

Methane capture It also increased the capacity to harness biogas produced by the lagoon process. This is use d to generate electricity, thus significantly red ucing greenhouse gas emissions.

When fu lly i mp l emented, the Environment Improvement Project w ill double the amo unt ofbiogas captured at the site, allowing at least 7.2 MW of power generation to be developed on the site.

This w ill allow the site to be close to energy neutral, and achieve very large reduc tions in greenhouse gas discharges through m ethane capture and alternative electricity generation.

Economic benefits By implementing the Environment Improvement Proj ect to upgrade the plant, Melbourne Water will achieve the desired environmental outco m es w hile maximising use of existing assets and nunimising capital cost.

W itho ut effective managem ent of the enviro nmental impacts on Port Phillip Bay, Melbourne Water would have needed to consider alternative trea tment processes such as a full-scale m echanical treatment plant at a potential cost of up to $750 million. By comparison, the overa ll cos t for th e Env ironme n t Improvement Proj ect, to be finished by 2005, was set at $124 million.

The total capital cost to da te for the SSE Lagoon Project has been $32 million.

This is below the budget figure of $35.6 million.

The capital cos t of SSE Lagoon Project, including the initial capital cost of the lagoo ns, together with the final upgrade cost, has resulted in a substantially lower financial spend than is typical for similar wastewater "'treatment plants.

T he operating cost of the project (a bout S40 per ML) is also well below that of conventional solutions. T his has been ac h ieved b y th e hi g h degree of automation and low energy use of the facility.

The Authors Brad Mclean and Peter Scott are senior managers within Melbourne Water, the Government-owned corporation that owns and operates Western Treatment Plant. Brad M cLean is Team Leader, Western Treatment Plant Planning, and Peter Scott is Group Manager, R esearch and Technology.

HAWK MEASUREMENT SYSTEMS Sludge Interface Monitor The world ' s leading ultrasonic manufacturer, Hawk, has now developed and successfu lly tested a new range of sonar interface uni ts for use in primary and seco ndary clarifiers, IDEL and IDEA pla nts as we ll as DAF pla nts a nd potab le water clarifiers. W e offer con tinuous level measurement of the blanket for pump control as wel l as monitoring the fl uff layer for water q ua lity. Po int density ana log ue for monitoring water density changes and sonar point swi tch devices . We a lso have a portable density ana lyzer that can be calibrated to work in water to sludge density. Al l instruments are 100% A ustra lian made and come with a two year warranty .

82

WATER MARCH 2 00 2

INNOVATION:

WASTEWATER

TREATING ARSENIC MINE WATER USING A HYBRID MEMBRANE PLANT P Macintosh Bendigo Mining NL has contracted Occtech Engineering Pty Ltd of Perth to design and install a sophisticated water treatment system to allow environmental 11se of water extracted from the historic, now newly constructed, 11nderground mine workings. The water has a uniq11ely complex mix of salts, hydrogen wlfide, m etals, arsenic and biological oxygen demand.

Background of the Mine

Historically the mine waters were discharged into the local creek system , a prac tice w hich t o d ay is co n sid e r e d t o t ally unacceptable. For the new mine, num e ro u s o ptions for wa te r disp osal we re considered w ith either treatment of the w ater for release into the local creek system or extension of the existing evaporation ponds being identified as the most viable alternatives. Although space was available fo r evaporation the long-term impact o n local r es id e nt s, r e m e diati o n a nd corporate values made this optio n less attractive . Treatment, at a similar cost, provided a possible beneficial use of the released wa ter and wo uld partly restore a local creek system .

Following the first discovery of View of Bendigo's Pall Mall - circa 1890 gold in 1851, Bendigo became one of the most ac tive and productive unimaginable amount of information. In gold regions in the w orld and resulted in planning BMNL has mapped the historical the birth of the current Bendigo township data as a 3D m odel (Figure 1). in rural Victoria. There we re over a The natural presence of pyritic ores, thousand operating mining companies and high alkalinity and arsenic has created over 5,000 vertical shafts and co untless The Technical Challenge mine w aters difficult to treat for disposal. kilometres of ho rizontal developments In addition, many of the old vertical shafts During the current phase of mine were dug under w hat is no w the township were used fo r rubbish disposal, thus development, 1. 66 ML/day of water proper. Mining ceased in 1954. Even leaching organics in to the mine wa ter. needs to be discharged from the system . today the collapse of old shafts from T he contrac t extends to a throughput of C onsiderations of safety and operability fo rgotten histo ric diggings occurs on in the new mine require the access decline up to 12 ML/ din the next two or three dom estic properties . and adj acent shafts to be continuously years. T h e water contains unacceptable Bendigo Mining NL (BMNL) has the dewatered. levels of dissolved salt (T DS), hydrogen mining rights to the whole of th e sulfid e (rotten egg gas), B endigo Goldfield. The gold arsenic, carbonate alkalinity min e ralisa ti o n zo n es are and other m etals (iron and located o n the numerous Table 1. Key Water Quality Parameters m angan ese) as well as som e anticlines, the peaks of the BOD. T he most challenging Parameter (all as mg/L Mine Recovered Treated Water waves of sedimentary rocks. species is arsenic, particularly unless noted} Water Quality Quallty Targets T he gold is present predomas the traditio nal arsenic 5.0 - 6.0 PH 6.5- 8.5 inantly in rela tively large rem oval pro cess requires pieces, nuggets, distributed in 5 ,100 1000 TDS, mg/I contro lled oxidati o n and the qu artz veins. With the TSS 50 30 adsorption, and this is clearly knowledge of the location of Turbidity, NTU 15 25 difficult du e to the presence the anticlines the historic BOD 15 20 of competing H 2S and BOD. miners sunk shafts to w h ere 15 ND The mine wa ter quality and gold bearing zones might be the target for discharge to Total Hardness, as CaC0 1500 NS 3 exp ected. What they were r ece i v in g w at e r s 1s NS Total Alkalinity , as CaC0 3 1100 unce rtain about was the summarised in T able 1. d~pth of such zones and as a As 5.2 0.05 result success w as variable.

Hg 0.001 Treatment The legacy of the histo ric Zn 0.05 T he treatment fo cus w as min e r s in cl ud es sha ft s Fe 1.33 0.5 to address the removal of the ave raging 300 m etres in ND: None detected H 2S in a controlled fa shion , depth with some in excess of NS: Not specified pr ep ar e th e str ea m for 1400 m etres, and an almost

84

WATER MARCH 2002

INNOVATION:

WASTEWATER

Figure 1. A 3D computer generated image of the historical underground shafts and workings. The new access decline (in grey) and some newly identified gold bearing zones (red).

oxidation of the arsenic and achieve forced-ventilation tower. T he overhead conditions suitable for the adsorption of air flo w is oxidised and de-odourised in a bio-filter. the arse nic in a chemically induced flo e.

T he stream wo uld then be desalinated by • O xidant (hypochlorite) is added to R everse Osmosis (RO) so pre-filtration " mop " up residual H 2S and oxidise the wo uld be needed to attain low levels of arsenite As+3 to arsenate As+5 . The residu al oxidants, suspended solids, process will still have a small residual of sparingly soluble salts, and the fouling C O 2 . Adequate time (+ 20 minutes) is effects of iron and manganese. provided in an oxidation pond to A number of alternative pathways for complete the chlorine oxidation process . treatment were examined with the assisThe process pe1forms best at pH 6.0 - 7.0 tance of the Australian Nuclear Science • As the water flows from the oxidation and Technology Organisation (ANSTO) pond the pH is adjusted to the optimum which has a number of patented processes pH for removal of arsenic by flocculation. for the oxidation of arsenic. Ultimately a Ferric salts are added in a rapid mix zon e new process was selected due to the that over-flows into the mixing pond complications afo rementioned. Arsenic w here iron floe is formed to adso rb the exists as various oxides and unlike most soluble arsenate ion. metal oxides remains reasonably soluble.

• The mix_i_og porn:,! ov~.r.fl9w io !9 .a R~ienj o.,:i of .r.be :m.e.,:ifr spufrs .by RO larger pond to provide residence time for alone wo uld have been ineffective as arse ni c is pr ese nt as an un c h a r ged sp ec i es or a monovalent anion. To address this a combination of process steps was required.

There was potentially a high demand for chemical oxidants, so air stripping of the volatile H 2S provided a significant reduction in operating ch emicals and provided a more consistent fe ed stock prior to oxidation.

The treatment system is as follows: • Acidification fo llowed by H 2 S and CO 2 stripping in a View of Bendigo Gold Fields - New Chum Gully - circa

86

WATER MARCH 2002

the settling of the iron flo e and other suspended solids. Supernatant water is pumped to the filtration plant. Sludge collected in the pond will be periodically removed by sludge pump.

• Four multimedia filters are operated in parallel. They are sized so that three ca n operate at any one time w hile one is in backwas h mode. Backwash is returned to a waste/ overflow collection system to be piped to the existing evaporation ponds.

• A reverse osmosis plant reduces the TDS and furth er redu ces the concentration of arsenic. The permeate design rate from the plant is 1.44 M L/ d.

Blending around the plant w ill increase the disposal capacity to 1. 66 M L/ d. The design recovery is 80%, however, this may be adjusted based on operating exp erience .

• The RO design necessitated a multistage plant with inter-stage boosting.

R ej ect water from the plant is forwarded to the existing evaporation ponds. The permeate is dosed with a low level of ca ustic so da (NaOH) for final pH adjustment. The RO plant is fitted with a data logger w ith remote access to enable monitoring of key operational variables .

The arsenic reduction process is unique in the ch emical difficulty it presents and in the technology applied. A number of process risks were identified. For each of the process risks a mitigation or alternative treatment plan was been identified assuring security of process into the futur e.

C ommissioning is planned for July 2002.

Particular aspects of the treatment process are the subj ects of a Provisional Patent held by Occtech.

The Author Peter Macintosh FIE (Aust) is Director of Occtech Engineering, Perth,

W..A.,. .a Jpt~i<YiH

jn,

mdJ.i.i;J:.r.W byb;:i.Q-

membrane tr ea tm e nt te c hnolo gy, including water treatment and re-use, efflu ent treatment, and zero discharge for a range of industries including mining a nd mineral pro cess in g, chemical and petroch emical manufacture and water and was tewater treatment. The co mp a n y h as s p ecia l ist exp ertise in cyanide, acid , radioac tive and' heavy m etal treatment systems . 288 Stirling Street, Perth, W .A. 6000 , Tel: 61-89228 1522 , Ema il: Peter .Macintosh@ occtech.com.au, W e b site: 1890 www.occtech.com.au

INNOVATION:

WASTEWATER

COCOS {KEELING) ISLANDS WASTEWATER TREATMENT PLANTS C Shinton A wastewater treatment so lution for a sensitive environment, incorporates two Australian developments: The Sinkair Aerator and the Gas Lock Siphon Decanter.

The Cocos or Keeling Islands are two separate atolls in the Indian Ocean, approximately mid-way between Perth and Sri Lanka, comprising 27 coral islets, low lying with a dense cover of vegetation, a total area of 14 sq km, and a m aximum elevation of 5 metres above sea level In the mid 1990's concems were raised about the detrimental impact of the septic tank disposal system on the only fres h water o urces, which comprise shallow lenses over sections of each Island.

Plant under construction

Following a detailed inves tigation it was proposed to replace the existing system with a vac uu m sewerage system and a was tewater treatm ent plant.

Success ,brous" Partn ership

/ Advanced Water Treatment / Biological Nutrient Removal / Plant Auditing & Optimisation / Water Recycling / Infrastructure ~tanning & Modelling / Design & Implementation / Strategic Planning & Developer Charges For informat ion r e garding JWP's project ca pabilit ie s, pleas e co ntact : Selwyn Mcfaul in Brisbane on 07 3244 9600 (s .mcfaul @jwp .com.a u ) Gidi Azar in Sydney on 02 9460 1855 ( g .azar@jwp .com .au)

www.jwp.com.au 88

WATER MARCH 2002

Simon Engineering's Water and Wastewater division successfully tendered to design , construct and commission two was tewater treatment plants, one each on West and Home Island.

The pl a nt s are b ased on th e In termitten tly D eca n ted Exte nd ed Aeration (IDEA) process designed to treat 70 and 100 kl/ day of raw sewage (EP 280 and 420) w ith influent loads of300 mg/ I BOD 5 , 300 m g/ I suspended solids, 70 mg/I nitrogen and 15 mg/I phosphorous.

The process is designed to reduce these constituents to <15 mg/ I BOD 5 , <20 m g/ I susp ended solids and <10 mg/ I nitrogen before disinfection and discharge to an ocean outfall. Early test results have produ ced results of <5 mg/ L for BOD 5 , SS & TN. Each plant comprises an inlet m uncher, Intermitte nt Aeration Tank (IAT), Effiuent Storage Tank (EST), treated effiuent pumping and UV disinfection and Sludge Drying Beds.

R aw sewage is received thro ugh the muncher into the IAT for treatment.

Treated effluent is decanted into the EST before being pumped thro ugh a UV disinfection unit to the ocean outfall.

Waste activa ted sludge is pumped from the IAT to covered slud e drying beds, 9 with filtrate being returned to the IA T. The performance of the IAT as a fill and draw clarifier is one of the most important and innovative aspects of the intermittent process. T he IAT aeration operates intermittently, typically 8 to 15 hours per day, on an ae rate/settle/ decant

INNOVATION

Weather proof motor

Low head highflow pump with screw impeller

Sinktube directs turbu lent column of bubbles to floor of tank

Primary circular mixing caused by

Rising bubble plume

wat er momentum

cycle. In this environment th e utilisation of the biodegradable organic material and nitrification is completed, with denitrification being completed during the settle and decant phase. The IAT can operate on sludge ages typically of 50 days .

The IAT is fitted w ith Simon Engineering's patented Sinkair aerato rs (see insert) that are fitted with mixed flow imp ellers that provide rag-handling

WASTEWATER

capability, so that no screening is r equir ed . A rag catc h er is provided in the IAT to facilitate rag removal. The Sinkair aera tors have been develo ped to provide efficient and cost effecti ve oxygen transfe r by ma x imi sin g air entrapment and diffusion w hile utilising the flo w dynamics of the ae rator to ensure effective tank m1xm g.

D ecan t is ac hi eved usi ng Simon E n gineering's uniqu e patented Gas Locked Syphon D eca nt Mechanism. Carefu l design of the tank and decanting m ec hanism ensures solids-free efllu ent is decanted under all inlet fl ow co nditions, an esse ntial requirem ent w hen the cyclone season rainfall is considered.

The overall design is based on process simplicity, robustness and a low maintenance system suitable for remote location.

At the time of w riting (D ecember 200 1), Home Island plant has achieved stable operation and complian ce testing is underway . The constructio n of West Island plant is approaching prac tical

Automatk vent value

Effluent outlet

Clear effluent in â&#x20AC;˘u â&#x20AC;˘ tube to

trap air

Water level

above manifold

Manifold acts as submerged weir when trapped air

Water level

is vented

short distance

pushes air up vert ical pipes a

completion w ith start up scheduled for January 2002.

The Author Chris Shinton is currently Proj ect Manager w ith Simon Enginee ring Australia and has extensive experience in constru ction and project m anage ment in wastewater and pollution control in large scale processing facilities . Phone (02) 9887 6326, chris.shinton@simcar.com.au

mace= The force In flow.

INNOVATION:

WASTEWATER

IMPROVING THE ENVIRONMENT NATURALLY J Wilkinson Ph ragmites Austra lis has becom e the latest partner with Portland Coast Water in the treatment of wastewater from the Victorian southwest coast town of Portland. Based on CSIRO research, the plants peiform tertiary treatment in the largest reed bed system operating in Australia.

Primary/ si condary treatment is effected in aerated facultative lagoons which occupy approximately two hectare of the overall site . They are four m etres deep w ith a capacity of 28 megalitres and are each fitted with two 11 kilowatt aerators. They can deal w ith 640 kilograms bio ch emical oxygen demand per hectare per day.

The Challenge: the Call for Clean Coasts In recent years, Portland Newly planted reed beds Coast Water has searched for would be utilised on land where practiinnovative ways to treat wastewater at its cable. Phragmites Australis was the answer. main trea tme nt plants at Portland , Heywood and Port Fairy. At Bald Hill, Planning for the Future outside the C ity of Portland , Phragmites D etermined to provide the best, most Australis has proved to be the right answer. cost-effective soluti on to the was tewater Portland has a pop ulation of abo ut treatment problem and seeking the 10,000 and is a major Victorian regional highest standard effiuent for disposal, centre and the third largest port in the Portland Coast Water commissioned State after Melbourne and Geelong.

WSL Consultants Pty Ltd to design a new Alcoa's large aluminium smelter is located wastewater treatment facility on a 25 there ; woodc hips and livestock are hectare site near the Alcoa aluminium shipped from there . It is a tourist destismelter, adjacent to the aged ocean nation and in the summer months the outfall. T he facility was required to cop e populations of Portland and other coastal with an average dry weather was tewater towns swell enormously . fl.ow of 4 ML/ d but capable of handling Up until 1995, all of Portland's 6 ML/din the future. wastewater was discharged untreated to Table 1 summarises the raw sewage the ocean at N elson Bay some five quality, Table 2 the limits imposed by the kilometres from the city. Nelson Bay has Victorian EPA. an attractive stretch of coastline bounded by high cliffs which impede access from the land side.

In the '90s, communities living on the fringe of the continent, along our coastlines, demanded that discharging raw sewerage to the ocean cease.

Victor i a's Environment Protec tion Authority took up the cry and imposed conditions on water bu si n esses servicing Victoria's coastal towns.

For Portland Coas t Water, the challenge was to provide treatment which wou ld b e suitab le for discharge to the ocean in the short term but w hich

Nature Steps In

Constructed reed beds were originally pioneered by the CSIRO and Portland Coast Water obtained a licence from the CSIRO. Twelve reed beds were engineered for tertiary treatment, with six h ectares planted with Phragmites Australis.

T he design of the inlet and outlet piping for the reed beds allows for operation either in parallel or in gro ups of three beds in series. The parallel operating mode is the normal mode of operation but operation in series can provide a higher standard of tertiary trea tment. Uniform distribution of primary effiuent to the reed beds is achieved solely thro ugh a system of weirs in the distribution pits. The variations in the levels of the beds needed to suit the topography of the site, proved a challenge in the distribution hydraulics - a challenge confronted and solved!

Establishing the reed Table 1. Raw Wastewater Quality beds required some 6,000 Unit Parameter Concentration square metres of carefully Five day biochemical oxygen demand (BODs) 160 mg/ L graded aggregate. Scoria, 120 Suspended solids mg/L co mmon in the local region, was used as the Ammonia nitrogen mg/L 120 basis for the beds. It is laid Organic nitrogen mg/ L 15 across the 12 beds to a 10 Total phosphorous mg/L uniform depth of 500 millimetres, using 10 mm Table 2. EPA Discharge Licence Conditions size for the main beds with Parameter Unit Concentration 40 mm size for inlet and 1 outlet zones.

Five day biochemical oxygen demand (BODs) mg/ L 90 perce nt ile<20 The depth of treated Suspended so lids mg/ L 90 percentile<30 effiuent flowin g through org/100ml 90 percentile<400 E.col i bacteria the reed beds is 450 m illi metres 50 Floating matter None millimetres below the top pH pH units >6.0 and <9.0 of the aggregate.

WATER MARCH 2002

91

INNOVATION

WASTEWATER

Table 3. Facility Performance Location

BODs

Reduction

Mg/L

%

160 36 22

n/a

Raw Wastewater Aerated Lagoon Effluent Reed Beds Effluent

84 39

* Effluent quality will improve as the reeds *

Phragmites Australis

To gain th e maximum contribution from the reeds, Phragm ites A ustralis seedlin gs we re planted every 1. 5 m etres over the area of each bed . Planting began in December 1999 and was completed in April 2000.

The facility was commissioned in March 2000 and during final construction, the reed beds were brought on line as soon as they were finished. Portland's reed beds are believed to be the largest of their kind in Australia.

ss

Reduction

mg/L

120 18 6

%

n/ a

93 67

develop

No biosolids are produced

Final cons tru ction costs for th e Portland was tewa ter treatment facility, including the facu ltative lagoo ns and the 12 reed beds, was $3 .5 million. Operating costs for a full yea r are exp ected to be approximately $64,000 for powe r and $3 ,000 for maintenance - low by industry standards.

The reed beds polish the lagoon e fflu e nt by furth e r reducing th e bio c h e mi ca l oxygen d e mand a nd suspended solids, as shown in Table 3.

They also reduce nutrient levels, particularly phosphorous. T he treatment facility has no daily produ ction of bio-solids; is odou rless and noiseless and creates no daily concerns that w ould require a sp ecialist op erator.

So , on from the aerators in the fac ultative lagoons, nature does all the wo rk!

C urrently Portland Coas t Water's wastewater trea tment facility reuse 10 per cent of th e treated efflu ent. In Portland wastewater is used to irrigate seven hectares of tree lots planted with a variety of fast-growing eucalypts and so me cypress . To minimise the potential impact on the marine environment, Portland Coast Water is currently developing a reuse strategy with the aim of significantly increasing the volume of wastewater re used at Portland . This will further reduce discharge of treated w astewater to the ocean.

The Author John Wilkinson is C hief Executive, Portland Coast Water.

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WATER MARCH 2002

INNOVATION:

ENVIRONMENT

DYRESM: DYnamic REservoir Simulation Model J Antenucci, D Horn Predicting water quality problems likely to develop in lakes and reservoirs is one of the keys to preventio n, and ill this regard, the Centre for Water Research (CWR) at The Univers ity of Western A ustralia is at the forefront with its onedimensional hydrodynami c model DYRESM and its compleme11tary aquatic ecologica l model, CAEDYM.

Managing Lakes and Reservoirs Lakes and reservoirs are an important reso urce across the wo rld. They provide fres hwa ter fo r drinking, agriculture and hydroelectri city . They have environmental and ecological valu e, supporting important bio-diversity in aquatic flora an d fa una and sustaining important fisheries . They are vital for populations

Figure 1. Diagram of th e DYRESM process

of migratory birds. Y et lakes are coming under increasing pressure from development . M any lakes are subj ect to d eteriorating wa te r quality du e to increasing nutrient loading from agricultu ral run-off and urban wastewater and

du e to polluta nts rom indu stri al discharges .

The seasonal development of th e tempera ture stra tifica tio n in a lake o r reservoir is of pa1ticular impoitance . M ost lakes and reservoirs are temp erature stratified for at least some period each year and this has significa nt impacts fo r the biological and chemical pro cesses that determine the wa ter qu ality in a lake.

O xyge n d e pri v ati o n in th e c o o l hyp olimnion and the adjacent sediments can result in the dissolution of iron and manganese with the consequent release of ph osph o ru s. Also, potentially to xic cyanobacteria are known to favour stratified conditions in which their buoyancy co ntrol offers th em a comp e titi ve advantage ove r other algae.

or a w ho lly-owned Australian company only founded in 1995, Ecosol hos not token long to become a leading provider of stormwoter filtration systems that is committed to restoring wa terways to the way nature intended. The company is now actively marketing and selling the world' s most effective stormwoter filtration tech nology, the award winning Rapid Stormwater Filtration (RSF).

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'Ecosol's water filtration system a winner for the environment'' Ecosol's stormwoter fil tration systems ore provided to local government, property developers, and commercial site owners. Systems provided include those for at-sourc e roadside stormwoter pits and for end-of-line stormwoter and sewage outfalls to rivers and waterways. Ecosol also offers cleaning and maintenance for all of its water fil tratior systems.

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INNOVATION

E n g in ee r s a nd wa t e r r eso ur ce m a n age r s h ave devised an a1ny of strategies to mitigate these problems and to man age wa t e r qu ality m ethods such as catchment ma n age m e n t, se dim e n t r e m e di a ti o n, se l ec ti ve withdrawal, destratification and hypolimnetic oxygenation .

ENVIRONMENT

DYRESM provides a qu a ntit a ti ve t oo l for predicting the stratificatio n and, w hen combined w ith C A E DYM , th e wa t e r _., quality in lakes and reservoirs and fo r the assessm ent of options fo r their remediDVRESM ation and m anagem ent. It is -10 w idely used by engineers, envir~nmental m anage rs, Modelling reserv oir op e rat o rs and _., scientists fo r managing water An y m an age m e nt to o l ....,,, ...., Jan98 quality in lakes and rese rdesigned to predict wa ter voirs, as well as in the design qu ality must be able to m odel of new dams. It is used in the physics of the system many different applications, correctly if any quantitative 10 from natural lakes and m anassess m e nt of alt e rna ti ve Figure 2. Comparison of measured and simulated m a d e r ese r vo ir s, t o ma n age m ent strategies o n temperature profiles over a four-year period from 1997r e h abilit a t e d op e n- c u t wa ter quality is to be carried 2001 of Lake Kinneret, Israel. mining pits. o ut. R ece nt adva n ces in of entrai nment and mixing and insertio n deskto p computing p ower and o ur As an example, Figure 2 compares at th e depth of neutral bu oya n cy . increased unde rstanding of the hydrodym eas ured and simulated temperature R eservoir w ithdrawals include overflows namic and biogeochemical pro cesses in profiles over a four-year period from and independently scheduled off-takes at lakes has led to the development of 1997-2001 of Lake Kinneret, Israel. various depths. The model also includes increasing sophisticated computer m odels D YR ESM reprodu ces the o bse rve d bubble-plum e destratifier and surface capable of predicting changes in wa ter seasonal stratifica tio n from April to imp e ll e r o pti o n s fo r r ese r v oir quality w hether from increasing pressures D ecember each yea r of the simulation m an age m en t . Imp o rta ntl y, b eca u se fro m development or fro m the impleperiod . Each spring, the increasing solar DYRESM contains explicit descriptio ns m entatio n of m anage m ent strategies radiation heats the ~urface wa ter in the of physical processes, it requires no designed to improve water quality. lake so that the surface temp erature calibration when it is applied to new sites. steadily rises from a winter mixed temperDYRESM (the DYnamic REservoir The concept is illustrated in Figure 1. ature of approximately 15°C to a Simulation M odel) is a computer m odel used to predict the stratification in lakes m aximum of approximately 30°C in late CWR later developed an aquatic and reservoirs over seasonal and decadal summer. As summer turns to autumn, the ec o l o g i ca l mod e l , C A E DYM time scales, making it an important tool smface of the lake cools and the smface (C o mputati o n al A q u ati c E cosys tem layer deepens. Eventually the smface water fo r scientists, engineers and managers. T he Dynamics Model), w hich can be used to t e mp e r a tur e r eac h es th a t o f th e internationally-ac claimed model was simulate wa ter quality problems such as developed at CWR in the 1970 's and is hypolimnio n and the lake mixes. algal blooms and low dissolved oxygen under continual development, with a new co n ce ntr at i o n s and t o eva lu a t e T he strength and duration of seasonal ve rsion due to be released in April 2002. m anagem ent strategies such as destratifistratification is important fo r the w ater ca ti o n, se l ec ti ve w it hd r awa l and The one-dimensional model is based quality in the lake since it determines the catchment m anagem ent options. on an assumption that the variations in the vertical distribution and ve rtical flu xes of ve rtical DIMENSION play a dissolved oxyge n , nutri ents more important role than variaand phytoplankton. Figure 3 DVIU!S M -CA !! DVM S lmu11 110n Llk• Klnntr tl 1987 - 119 tion s in th e hori zo nt al sh o w s th e r es ult s of a direction, so the lake is represimulation of the coupled water 10 sented as a series of horizontal qu ality mod el DYRESM" !. 20 layers that are dynamic in C AED Y M. Th e m o d e l in ~ 30 time . T h e m o del includes successfully reproduces the lack "40 surface them1odynamics, incorof the Peridinium spring bloom po rating the effects of sho rtin 1997 and its reappearance in J ll"IM IA IM iJ I J l• IS ID IN ID I J IFIM IA I M I J IJ IA IS Mon th and long-wave radiation and 1998 - an important ecological sensible and latent heat flu xes. pattern currently under invesSurface m ass flu xes du e to tigation at CWR. rainfall and evaporation are also Lake Diagnostic System 70 included. A surface mixed-layer model parameterises processes DYRESM relies on good 40 such as convec tive mixing, quality data and' for this it calls J lf'IM I A I M IJ IJ IA 18 1 0 IN 10 IJ ll"IM IAIM I J I J IA 19 wind stirring and w ind driven Mo nlh on th e Ce ntr e' s L a k e shear mixing at the base of the Diagnostic System (LDS). The 100 200 ,oo mixed laye r.

LDS is a unique diagnostic OINOF UQ Ct'III /l Inflow dynamics allow fo r system designed to assist in the Figure 3. Results of a simu lation of the coupled water both surface and plunging managem ent oflakes and reserinflows and include the effects quality mode l DYRESM-CAEDYM . voirs and consists of a lake Field

-10

lI ~ ~ ,f (J~lI

t: I

.

20

-

.

-.

.

94

WATER MARCH 2002

30

INNOVATION

station and shore station, which communica te via telemetry. T he lake station meas ures the wa ter column temperature profile and the wind speed at the centre of the lake and transmits this to a shore management station in real time via telem et1y. CWR has successfully deployed these systems in lakes and reservoirs aro und the wo rld including Lake Burragorang (A u strali a) , Brownlee Reservoir (USA), Lake Kinneret (Israel), San Roque Reservoir (Argentina) and Lake Constance (Germany, pictured in Figure 4). These system s are all remotely monitored at CWR in Perth. . The LDS enables the lake to be monitored for stratification and helps to determine the extent to which the lake as a w hole wo uld mix in response to wind forces at any time, using the lake number concept. The temperature and w ind data collected by the LDS is then used to validate DYRESM, w hich can then be used in a predictive mode to forecast the outcomes of propo sed management strategies .

Real time data acquisition, coupled w ith incident response modelling and forecasting, is the future direction oflake

ENVIRONMENT

Figure 4 . Th e Lake Di agnosti c

System (L OS) station and reservoir manage ment. These tools provide the basis for this managem ent system.

Continued Development DYRESM was first developed as a research tool in the late 1970s (Imberger et al. , 1978). During the 1980s, the scien-

tific basis for the model was confim1ed and validated through laboratory and fi eld experiments and further features such as selective withdrawal (Hocking et al., 1988) and bubble p lumes (Patterson and Imberger, 1989) were added.

During the early 1990s, the ability to predict wa ter quality was incorporated into the model (Hamilton and Schladow, 1997; Schladow ~nd .,.H amilton, 1997) .

Improvements were also made to the scientific basis for the model, as new discoveries were made in the field.

The late 1990s saw the commercialisation of the model, with the model structure re- designed so as to incorporate the latest advances in computer scien ce.

Since D ecember 2000, the model has been available as freeware via the World Wide Web and the model can be downloaded from the following web site: http: / /www.cwr. uwa. edu .au/services DYRESM is now truly an international innovation, with more that 300 users in 45 countries . The model is used in de ve lopin g co untri es su c h as Bangladesh and Uganda, in arid environm ents such as Turkey and Chile, tropical environments such as Indonesia and

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WATER MARCH 2002

ENVIRONMENT

Thailand, and in highly developed enviro nments such as Western Europe . The breadth of its application m eans that the model is considered to be a fund amental tool in the management of surface water bodies .

T he model has been used for stu dies of Lake Kinneret (also known at the Sea of Galilee, the Lake of Gennesaret or the Sea ofTiberias) , the 1998 Cryp tosporidh11¡11 alert at Warragamba D am, NSW and the environmental problems in Lake Maracaibo , Venezuela. le is also currently used as a teaching tool at The Uni versity of Western .c Australia, Stanford University (USA) and Penn State University (USA).

The success of DYRESM is due to the sound scientific and engineering principles on w hich it is developed. The model is very rob ust, giving excellent res ults in a va riety of appli cations and enviro nm ents. Importantly, DYRESM has continu ed to evolve over the past 20 years and is currently being developed by an international network of 25 research partners in 16 countri es.

One of the strengths of this development strategy is that for free access to the model source code, these research partners provide two key services. Firstly, they act as beta- testers, reviewing the performance of new releases of the software, assisting in finding and fixing bugs in the code and making suggestions for the codes improve ment. Secondly, each research partner has been chosen on the basis of th eir scientific research abili ty and their potential co contribute to the development of new algorithms for the model.

T hese research partners use the CWR models in their research of new ideas in wa ter quality i'ssues and the results of their work are used in the further development of those models. These key partners are firmly focussed on scientific research ensuring that th e development of the suite of CWR models remains at the forefront of available technology .

Recognition In recognition of its importance to th e water ind ustry, DYRESM has been included in a new Land and Water Australia database that lists top innovations in science and industry over the past 10 yea rs. T he Innovations D atabase is a web-based facility with a powerful search capability covering a range of innovation types: advances in major Natural Reso urce Managem ent (NRM) issues, new technologies, science breakthrou ghs, new NRM concepts, best practice guidelines, managem ent tools and so on.

The extension ofDYRESM to include water qu ality was the reason for Land and Water Australia's involvement in the development of the model.

The Authors Dr Jason Antenucci is an Environmental Engineer and Limnologist at the Centre for Water R esearch with a PhD in environmental fluid dynamics. H e manages the ongoing development of the model DYRESM. Telephone: +61 8 9380 2048; e-mail : ancenucc@cwr. uwa. edu. au. Dr David Horn is a C ivil Engineer w ith a PhD in Environmental Fluid Dynamics. H e is the Manager of the Contract Research Group and responsible for co mmercial proj ects both within Australia and overseas. Telephone: +6 1 8 9380 1684; e-mail: horn@cwr.uwa. edu .a u.

For more information abo ut DYRESM and other models under development at CWR, visit the Centre's website at http: // www.cwr.uwa.edu.au / services

INNOVATION:

ENVIRONMENT

INSTITUTE FOR SUSTAINABLE FUTURES M Jha In Australia and around the w orld, the pressure o n wa ter reso urces is increasing w ith popu lation grow th and urbanisation.

T here is also increasing conflict over water use with demand for irrigation competing w ith demand for residential and no nre~idential use , there is competition between States and nations and a growing aw areness of the need to restore environmental flows to natu ral wa terways .

With corp o ratisation of the w ater service industry, th ere is also a gro wing e mph as is on impro ving e co n o mi c effi ciency and removing cross-subsidies .

T hese fa cto rs together have meant that increasingly, water service providers are seeing valu e in inco rp o rating dem and m an age m e nt and int egrat e d wa t e r manage m ent into their decisio n- m aking framework.

The Institute for Sustainable Futures was established by the Unive rsity of

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T echnology, Sydney, in 1997 to w ork w ith industry, gove rnme nt and the community to develop sustainable futu res thro u gh resea rc h , co n sul tan cy an d training . The Institute has brought expertise in demand manage ment and integrated water management to its w ork w ith wa ter authorities ac ross the country .

R esearchers at the Institute have applied

and extended two impo rtant tools in this fi eld-least cost planning and end use analysis.

Least cost planning for utilities was develop ed in the electricity industry over the las t 30 yea rs. The Institute team has pioneered the application of the least cost planning approac h to wa ter dem and managem ent in Australia. It is based on the principle that p eople do not need energy or wa ter, they n eed the services that these provide, such as sho wers, landscapes and sanitation , w hich ca n be provided by improving efficiency, rather than increasing supply.

By redefinin g the role of utilities as providers of these services, rather than as suppliers of a commo dity, the options available to m eet custom ers' needs increase to include more efficjent equipment, practices and supplies of different services .

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E nd use analysis fo rms the basis for applying least cost planning to develop dem and m anage m ent p rogram s. T h e analysis involves breaking down the total w ater demand in tw o w ays : • b y sec t o r (res id e nti al , ind u stri al , commercial, instituti onal) and • by end- use within each sector (e .g. in the case of residential-indoor end- uses such as toilets, showers, kitchen taps, hand basin taps, and o utdo or end- uses such as car was hing and ga rd en wa tering).

T imes seri es mo dels for the adoption of appliances and fi x tures and their relative effi ciency levels are developed to .forecast dem and and cali brated using customer demand data.

T he Institute's publication, W ise Water Manage men t: A D eman d Ma nagement Ma nual fo r W ater Utilities, is the m aj o r so urcebook in A ustrali a in the fi eld.

In order to develop estimates o f the futur e average demand for wa ter, to determine least cost options to redu ce demand and to sa tisfy Operating Licence conditions to reduce per capita demand for wa ter by 35 per cent by 2001 , relative to the 1991 value, the Institute developed the Sydney W ater Least C ost Planning Model, incorporating a d etailed end use model.

ENVIRONMENT

The wa ter savings that w ill res ult from the , 25 m program include m akin g mo re wa ter available fo r environmental flows, redu ced ave rage dry weather was tewater flows, reduced energy use for p umping and hot wa ter and therefore redu ced greenho use gas emissions.

D emand manage m ent is a co ntinu o us pro cess r e quirin g monit o rin g a nd assess ment of the programs that have been implem ented, to allow program adjustm ents. The Ins titute has ca rried o ut a number of assessm ent proj ects, peLfo rming statistical analysis of wa ter dem and for program participants and co mpari son groups in Sydney, regional NSW and in K algo orlie-Boulder (WA).

An integrated wa ter manage m ent app roac h o ffers more sustainable options of managing wa ter , wastewater and st o rrnw at e r th an th e c onve ntion al approac h of treating each of them as separate entities .

T he Institute for Sustainable Futures has been helping wa ter autho riti es and o ther orga nisations to develop more sustainable solu tions in n ew d evelopme nts and buildings and also in developments w here th e wa ter and sewerage infras tru cture has reached the end of its life cycle and is du e for replacem ent. Solutions such as decen-

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The Author Meenakshi Jha is a R ese arc h Consultant in the Sustainable W ater Team o f the Institute fo r Sustainable Futures, University of T echnology, Sydney.

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tralised water and wastewater systems. Such developments provide a unique oppo rtunity, as they are mo re am enable to integrated wa ter manage m ent approach.

Proj ects that the Institu te has und ertaken in this area include • Co n ce ptu a l D es i g n of W a t e r M anage m en t System fo r the 60L G reen Building for Au stralian Conservation Fo u ndation and Su rrow ee Pty Ltd , M elbo urne. " • Integrated Water M anagem ent SystemK ogarah Tow n Squ are R edevelopment.

• " Yo ur H o rne" - J ointly Funded by C ommonw ea l th G ove rnm e nt a nd B uilding & C onstru ctio n Ind ustri es .

• P roj ects on sustainable urban wa ter use fo r M elbo urne wa ter utilities as part of the M elbourne W ater Strategy R eview .

• Septi c Safe-Evalu ation of On site (wastewater system) options - Hornsby Co u n cil w it h grants receive d from D epartment of Local Governments, NSW. • On-site (wastewa ter system ) T rainingMul wa ree Shire Co uncil.

K2 Corporation Ply Ltd is a Victorian based company, which works throughout.Australia. Formed in 1999 the company is now in its third year with members having over Thirty Years of wastewater lrealmenl, design and construction experience. Project experience ranges from minor projects for neutralization and pH control to major industrial wastewater treatment systems including sludge de-watering.

Projects constructed for the period above have ranged in value from $1,000 la $1.5 million.

K2 Corporation Ply Ltd was incorporated in 1999 and the Managing Director Chris Stanley is active within the Company and has designed and constructed many wastewater treatment plants over the last twenty-five years. Chris is also active in the Australian environment movement.

K2 Corporation Ply Ltd has expertise with chemical/physkal treatment methods. K2 Corp can construct treatment plants for a wide range of industry and process types.

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ENVIRONMENT

MANAGING MANLY BEACH FROM SOURCE TO SEA B McRae Iti an imp ortant tourist beach area, several p ieces of innovative A ustra lian technology f orm part of community action, addressing the management of stormwa ter fro m source to sea.

A uniqu e pilot project is under way at M anly B each , just to the North of the Sydney H arbour entrance . The Manly Co uncil Stormwater Trea tment And R euse (ST AR) Project is unique in that it addresses all aspects of managing an urban stormwa ter catchment - preventing pollution by educa tio n and signage; so phisti cate d str eet swee pin g and screening at catch basins; treatment and reuse of rnnoff; and a monitoring program to assess effectiveness w ith key funding support from a N ational H eritage Trust Grant und e r t h e Co mmon weal th Government's Living Cities progra m

Urban Stormwater Initiative (USI), Manly Co uncil's environment levy, Sydney Water and the B eve ra ge I ndu stry Environm ent Council.

Tourism is the major economy for the Manly Region, known for its high e nvironm en t a l co n sc iou s n ess.

Consequ ently the preservation of M anly's environment, in particular its marine ecosys te m s, is imp o rtant to Manly Co uncil and to Australia's future. T he pilot proj ect, launched in August 2000 by Senator Robert Hill, will serve as a demonstration model for Australian coastal urban areas . Stormwacer corning from the M anly Ocean B each / Pine Street water ca tchment area provides challenges typical of urban beachfront environments: intensive development, high transient pop ulations and substantial

ve hicular traffic and litter. The net effect is urban runoff with "'relatively high levels of pollutant loading.

The STAR Proj ect takes an integrated ca tc hment m an ageme nt ap proac h , combining capital wo rks with so urce control measures. Litter traps fitted on drains screen out gross pollutants not stopped by preve ntative educatio n efforts.

The traps also capture some sediments, with more being removed by a comprehensive street cleaning program chat uses a M cDonald Johnson MADVAC unit and innovative porous paving from Australian firm Roda that is installed one section of road in the catchment.

Roadways constiwte approximately 14% of the catchment in the STAR proj ect area. This large impervious area, combined w ith the roofs .and paved areas

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of building sites, is a diffuse source of pollutants that are readily mobilised into the drainage system and from there to the beac hes . Id eally, direc tl y connected impervious areas should be minimised, but C ouncil's ability to address existing built sites is limited and redevelopment is a pro cess that proceeds slowly .

H owever, immediate benefits can be realised by replacing existing road and gutter systems with permeable surfaces that stretch fro m kerb to kerb . Permeable p aving sys te m s previou sly use d in Au stralia have been n ot been fully suitable for full traffic loads. The Ecoloc® pave rs used in the ST AR proj ect are concrete interlocking pavers that provide drainage voids betv,een the pavers. A base of clean 5mm aggregate is laid beneath the pave rs are in the voids betwee n pavers. This creates a pave m ent with a permeable surface that initially infiltrates over 200 mm/ hr, but has a similar stiffi1ess to a pavem ent constru cted from normal concrete interlocking pavers.

The major issue for successful use of a traffi cable p ermeable surface is a suitable subsurface drainage system undern ea th. Where a suitably p ermeable subgrade exists, the infiltrated stormwater

E N V I R O N M, E N T

The use of interlocking pavers created a permeable surface which reduced the normal runoff from street surfaces.

can be directed into the soil throu gh a p ermeable roadbase . Less permeable subgrades require a combinatio n of p ermeable drainage laye rs and dense roadbase that can direct the infiltrated stormwa ter to a suitable location, fo r example, a subsurface infiltration trench

Accurate Bulk Solids Feedling

adj ace nt to the roadw ay . The STAR Proj ect uses a no-fin es roadbase that enables stormwater to infiltrate throu gh to the sa ndy subgrade below . The roadbase is similar to normal transpo rt authori ty standards except for the lower percentage of mateiial that is less than

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1mm is size. Adjustment to the final roadbase specification to satisfy greater infiltration or loading requirements is possible, dep ending on which is more significant for the fina l design.

A 500- m e tr e pervious sect ion manufactured from recycled plastic by the Australian firm Atlantis, built into the drain, filters the highly polluted run-off from short tenn parking bays along Ocean Beach. It captures polluted stormwater from the corresponding road and carpark catchment. The Atlantis Eco Pavers are a permeable paving system that is strong and durable enough to handle traffic areas but allo w hi gh flow s of polluted stormwater to infiltrate into the next component of the Atlantis system.

After passing through the Eco Pavers the polluted stormwater is treated using Atlantis Ecosoils (Enviro-media). T his is an expanded polymer (again manufactured from recycled plastics) designed with sufficient stru ctural strength to carry normal pavement loadings. Containing naturally occurring microorganisms Enviro-media biologically degra des and remediates toxic chemicals that are the result of daily urban and industrial pollution. Typical contaminants such as hydrocarbons and metals found in road and car park runoff are treated without compromising the structural integriry of the pavement.

The microorganisms in Enviro-media degrade toxic pollutants before the runoff infiltrates into Atlantis Ecological C hannels. From the channels, purified water passes into 100,000 litres of Atlantis Ecological Tanks. No1folk Pines, a major feature of the Manly seascape, are then spray irrigated by use of a pump system.

Excess purified water overflows and percolates through the existing sandy site soils to recharge gro und water.

ENVIRONMENT

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Apart from testing innovative technology, the Manly STAR project has po we rfu l implications for planning regulation, urban design and stormwa ter pollution control. A monitoring program conducted by the Universiry of NSW's Water Research Laboratory and Sydney Water will measure the effectiveness and efficiency of the project. During the ST AR proj ect the Council is reviewing its Residential Development Control Plan to incorporate a focus on ecological su stainable d evelopm ent and total ca tchment management principles.

Council will also be participating in a complementary public ed u cat ion campaign that will emphasise the role that every person, including visitors, can

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play to dispose of litter responsibly and help improve water qualiry.

The Author Brian McRae is the Technical Director for the Au~tralian Water Association and a member of the ST AR Project team. This article was developed with the assistance of project team members: Eric Love (EC Sustainable Cons ultants, elo ve@b igpond.com), Richard Martin (Roda, martinr@ rocla.com.au) and Christian Urriola (Atlantis, christian@atlantiscorp. com.au).

Further information is available from the STAR Proj ec t Manager, Jo ann e Scars bri ck (j oa nne. scars bri ck@ bigpond.com) or by visiting the Urban Stormwater Initi at i ve we b site (www.ea.gov. au / coasts/ pollution/ usi / ).

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INNOVATION:

ENVIRONMENT

HYDRO-ACTIVE LIMESTONE TREATMENT(HALT)SYSTEM J Taylor A novel approach to the treatment of acid waters has been developed by Earth Systems. It uses low cost, locally available limestone aggregate to efficiently produce a hig hly reactive slurry that rapidly neutralises acidic water.

Why was the HALT system developed?

T h e large scale of acidifi ca tion processes such as acid mine drainage, acid rai n and acid sulphate soils often prevents the application of conventional treatment meth ods, largely due to the inordina te cost. T he most desirabl e treatment approach is often to use natural minerals such as li m estone and dolomite in aggregate form . For example, passive treatment techniques such as "limestone drains" and "lim estone w ells" have been in use for some tim e. While such technolo gies can be successful , the armo uring of limes tone gravel w ith neutralisation by-produ cts dramatically redu ces efficiency and cost effective ness .

Efficiency can be significantly improved by utilising powdered lim estone reagent, but costs rise as limestone grain size falls.

In order to provide a truly cost effective option for addressing this serious environmental problem, Earth Systems developed the HALT system to grind limestone aggregate on site and as requi red . The ultra-fine grain size of the limestone sluny makes the HALT system even more effective than typical limestone pow der.

How does the HALT system work?

Limestone gravel is stored in a hopper and automatically fed into a w ater- filled HALT mill. T his d ual chamb er ball mill grinds th e aggregate und er wat e r producing fin e particles at a controlled rate. T he limestone slurry is screened to control grain size then dosed into an acidic water body or stream. T he system can generate 1- 5 tonnes/ day of limestone in slurry form. Outp ut rates can also be controlled by adjusting the sys tem 's operating param eters such as mill rotation rate. T his treatment system is uniqu e in that acid w ater is not neutralised within the mill, but in the affected w ater body as the reactive plume is released.

Advantages of the HALT system For pH control, HALT systems offer numerous benefits over both conventional treatment systems. T hese include: • C ost-effective solu tion to a widespread and difficult environmental problem.

• Suitable for multiple applications (low to very high acid flux neutralisation tasks).

• Limestone is natural, environmentally benign and prevents overdosing.

• Rapidly neutralises most acid waters to pH 6.5-7 .5.

• The use of limestone avoids potential OH&S problems.

• Produces ultra-fin e grained particles for rapid reaction and very high effi ciencies of lim estone use (Table 1).

Table 1. Particle Size Distribution obtained from CSIRO sampling and analysis of limestone slurry produced by a HALT System utilising 250µm screens.

Particle size distribution Finer(%)

Diameter microns (11m)

125.00 63.00 53.00 31.00

100.0

20.00

78.4 74.7

98.0 94.0 84.6

15.60 7.80

62.8 50 .0 41.4 36.5

3.90 2.00 1.00 0.48

33.0

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INNOVATION

ENVIRONMENT

Potential applications HALT systems are usefu l fo r trea ting acid mine drainage fro m acti ve and abando ned me tal and coal mine sites . T hey can also be appli ed to acidified catchments, lakes, ri vers, streams and groundwa ter, impacted by Acid R ain o r drainage from Acid Sulphate Soils (eg. agricultural settings and development sites) . With the ability to rapidly and cost effectively adjust pH, HALT systems could be used for pre-treatmen t in conventional wa ter and was tewater treatment plants.

HALT deployment The HALT System shown in Figure 1 is deployed in N ew South Wal es, to deal w ith acidic discharges fro m agricultu ral land as part of th e Australian Federal Gove rnm e nt 's Coas tal A cid Sulphate Soils Program (CASSP).

T his system is configured to di sp e n se 1.5 tonn es / day of limestone in slurry form thro ugh 250~tm screens from a starting m ateri al of <5 mm limestone grave l. T abl e 1 provid es an analysis of th e particle size distributio n of the output slu rry. The ultra-fin e grained particle size of the limestone slurry generated in the HALT mill is the key to rapid neutralisation and highly effi cient limestone use .

Figure 1. HALT system deployed to treat dra inage from acid sulphate soi ls in New South Wales.

Reference Healy, N ., 1998, A mobile water treatm ent plant fo r small town wa ter suppli es. Journ al of the Australian Wa ter and Wastewa ter Associati on. Water; Vo l. 25 , No. 3, May/Jun e 1998.

The Author Dr Jeff Taylor is a Directo r of E arth Sys te m s w hi ch is an e n v ir o nm e nt a l r esea r c h , consulting and technology development organisation w ith almost 10 years experience in the field of water quality and treatment. It has developed a number of produ cts based on th e patented N eutraMill technology that have been used wo rld- wide for treatment of drinkin g wa ter (H ealy, 1998), w astewater and minesite wa ter ..

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THE NATIONAL WATER QUALITY MANAGEMENT STRATEGY (NWQMSJ. M Martin, C Lewis, N Hardy, P Callan Establishment of the NWQMS

In the early 1990's growing community concern about the condition of the nation 's water bodies and a greater recognition of environmental needs, led to d ema nd s for c h a n ges in the management of wa ter resources .

To address these concens two ministerial co uncils, the Agricultu re and Reso u rce M anagem e nt Co uncil of Au s trali a a nd New Zea l a nd (ARMCANZ) and the Australian and N ew Zea l a nd Env ir onme n t and Conservation Council (ANZECC) agreed in 1992 to establish the N atio nal Water

Q uality M anagement Strategy (NWQMS) to improve wa ter quality (ARM CAN Z an d ANZECC ha ve recen tly b ee n superceded by the Natural Resource Manage m ent Ministerial Co uncil). T he National H ealth and M edical R esearch Council (NHMRC) also became involved in those areas which affect public health such as drinking wate r. T he Council of Australian Governments introduced the Water R eform Framework in 1994 w hich covered a wider range of water resource issues and included support for the NWQMS. T he prime objective of th e NWQMS i s t o protect and enhance the Figure 1. National Water Quality Management Strategy: Documents (http://www.affa .gov.au/nwqms) quality of wa ter resources w hil e m a int a inin g Policies and Process for Water Quality Management econo mi c and soc i al 1 Water Qu ality Management - An Outline of the Policies (ANZECC/ARMCANZ) d eve l opment. This 2 Policies and Principles - A Reference Document (ANZECC/ ARMCANZ) (1994) includ es thr ee m aJ or 3 Implementation Guidelines (ANZECC/ ARMCANZ) (1998) el e m e nt s - poli cies, Water Quality Benchmarks processes and guidelines .

4 Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC/ARMCANZ) The policies encompass (2000) ecologically sustainable 5 Australian Drinking Water Guidelines - Summary (NHMRC / ARMCANZ) (1996) development, integrated 6 Australian Drinking Water Guidelines (N HMRC / ARMCANZ) (1996 amended 2001) catchment manage m ent 7 Australian Guidelines for Water Quality Monitoring & Reporting (ANZECC/ARMCANZ) (2000) and the use of econo mic measures. T he pro cess Groundwater Management covers the government 8 Guidelines for Groundwater Protection in Australia (ANZECC/ARMCANZ) (1995) and community develGuidelines for Diffuse and Point Sources oping and implem enting 9 Rural Land Uses and Water Quality - A Community Resource Document (ANZECC/ARMCANZ) (2000) catchment and water body 10 Australian Guidelines for Urban Stormwater Management (ANZECC/ARMCANZ) (2000 management plans. The 11 Australian Guidelines for Sewerage Systems - Effluent Management (ANZECC/ARMCANZ) (1997) national guidelines (Figure 12 Guidelines for Sewerage Systems - Acceptance of Trade Waste (Indu stria l Waste) 1) for key elements of the (ANZECC/ARMCANZ) (1994) wa ter cycle provide a 13 Guidelines for Sewerage Systems - Biosolids Management (*yet to be completed) co h e re n t approach to 14 Guidelines for Sewerage Systems - Use of Recla imed Water (ANZECC/ARMCANZ/NHMRC) (1999) water quality management 15 Guidelines for Sewerage Systems - Sewerage System Overflows (*yet to be comp leted) w hile allowing flexibility to respond to differing 16a Effluent Management Guidelines for Dairy Sheds (ANZECC/ ARMCANZ) (1999) circ umstances at regional 16b Effluent Management Guidelines for Dairy Processing Plants (ANZECC/ ARMCANZ) (1999) and lo cal levels.

17 Effluent Management Gu idelines for Intensive Piggeries (ANZECC/ ARMCANZ) (1995) The gutdelines in some 18 Effluent Management Guidelines for Aqueous Wool Scouring and Carbonising (ANZECC/ARMCANZ) cases have been revised or (1995) are subj ect to a rolling 19 Effluent Management Guidelines for Tanning and Related Industries (ANZECC/ARMCANZ) (1995) revision to reflect techno20 Effluent Management Guidelines for Australian Wineries and Distilleries (ANZECC/ ARMCANZ) (1998) 1o g i ca l , soc i a l a nd (Copies of the guidelines are available from : The Australian Water Association Ph. (+61) 029413-1288 or manage ment changes and Australian Government Info Shops Ph. (+61) 026295-4422 advances in sc ie ntifi c knowledge. The A ustralian

Protecting and enhancing water quality is essential in m anaging wa ter resources for sustainability in Australia . In Australia significant deterioration has occurred in water bodies since European settlem ent began over 200 years ago. These changes are associated w ith urbanisation and the development of agriculture and industry and have co me abo ut th rough the diversion of water for irrigated agriculture; the clearing of native vegetation for cropping and for grazing animals; and the disposal of industrial and domestic w astes.

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Drinking Water Guidelines and the Australian and New Zea land Guidelines for Fresh and Marine Water Quality are examples of this.

Australian Drinking Water Guidelines [NWQMS Document 6] Framework for Management of Drinking Water Quality: A Preventive Strategy from Catchment to Consumer

As Australia's primary reference on drinking water quality the Australian Drinking Water Guidelines (ADWG) provides guidance for the provision of a safe and high quality drinking water supply, w hich protects public health and meets the needs and expectations of consumers. To ensure the ADWG continues to emphasise preventative quality managem ent from catchment to consumer, a recent initiative has been the development of the Framework fo r Management efDrinking Water Quality (Figure 2).

The draft Framework has been developed by the NHMRC as ¡part of the Australian Drinking Water Guidelines. It has been specifically designed for application by the drinking water indust1y as a flexible risk management approach Its foundation is to promote an understanding of the entire water supply system, the events that can compromise drinking water quality and the operational control necessary for assuring the ongoing reliability and safety of drinking water supplies . It adopts an holistic approach, allowing monitoring to be placed in proper perspective, as a tool that assists in assuring the performance of operational processes and verification of product.

The 12 elements of the Framework (Figure 2) provide guidance on a full range of issues to be considered in managing drinking water quality.

BUSINESS

Figure 2. Framework for Management of Drinking Water Quality 1.

Drinking Water Quality Policy Regulatory and Formal Requirements Engaging Stakeholders 2.

The Authors Michael Martin is NWQMS Coordinator, at AFFA, Charles Lewis and Neal Hardy are with Environment Australia and Philip Callan is with NHMRC, Email Michael.Martin@affa .gov.au

Assessment of the Drinking Water Supply System Water Supply System Analysis Assessment of Water Quality Data Hazard Identification and Risk Assessment

3.

Planning - Preventive Strategies for Drinking Water Quality Management Multiple Barriers Critical Control Points

4.

Implementation - Operational Procedures and Process Control Operational Procedures Operational Monitoring Operational Preventive and Corrective Action Equipment Capability Materials and Chemicals

5.

Verification of Drinking Water Quality Drinking Water Quality Monitoring

The Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000)[NWQMS Doc. 4] and the Australian Guidelines for Water Quality Monitoring and Reporting (2000) [NWQMS Doc. 7]

The Guidelines for Fresh and Marine Water Quality are an extensive revision of the 1992 Guidelines with a different approach. Instead of setting absolute concentrations, the new Guidelines set out a process for determining locally applicable guideline valu es, relying on lo cally obtained data in a risk management fram ework. If there are insufficient local data, the Guidelines sets out default values, based on the best available information.

The Guidelines for Water Quality Monitoring and R eporting set out a systematic framework and checklists for action (accompanied by extensive reference material and worked examples) for establishing a monitoring and assessment program.

Both documents provide a rigorous basis to help implement the NWQMS process for water quality protection. They are expected to play a major role in developing water quality aspects of natural resource management plans under major national programs such as the National Action Plan for Salinity and Water Quality and the Natural Heritage Trust Mk2. This would include identification of environmental valu es of water bodies, developing locally applicable water quality guidelines and targets, deriving water quality objectives, input to onground management works, and monitoring and evaluation.

Both documents are available in hard copy (which includes a CD with purchase of the Water Quality Guidelines) and on the Web at http ://www.ea.gov.au/water/q u ality/ nwqms/index.html.

Commitment to Drinking Water Quality Management

Consumer Satisfaction Short-term Evaluation of Results Corrective Action 6.

Incident and Emergency Management Communication Incident and Emergency Response Protocols

7.

Employee Awareness and Training Employee Awareness and Involvement Employee Training

8.

Community Involvement and Awareness Community Consultation Communication

9.

Research and Development Investigative Studies and Research Monitoring Validation of Processes Design of Equipment

10. Documentation and Reporting Documentation and Records Management Reporting 11. Evaluation and Audit Long-term Evaluation of Results Drinking Water Quality Management Audit 12. Review and Continua! Improvement Senior Executive Review Drinking Water Quality Improvement Plan (For further information on the Framework contact Philip Callan, Health Advisory Section, National Health and Medical Research Council (philip.callan@nhmrc.gov.au)

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REFORMING AUSTRALIA'S WATER INDUSTRY G Samuel Australia's water industry is being transformed. The industry is becoming efficient and sustainable; it is delivering consumers higher quality water w ith grea ter security of supply; and the legitimate needs of the environment for water are being recognised.

Water is now regarded as a produ ct which should be properly priced, supplied by effi cient providers and the rights to which ca n be traded. Attitudes towa rds its use and cons erva tion have changed remarkably and its valu e is better appreciated. And remedies are being introduced for the external impacts of the supply and usage of water, environmental degradation in particular.

The need to have best practice in the provision and use of water is arguably stronger in Australia than in most other countries . Australia is the driest of the continent s and h as a fr ag il e ph ys i ca l environment. High p er capita water consumption has produced pressure on

w ater supply in many areas and environm entally stressed river sys tems. Th e associated falls in wa ter quality and security of supply and environmental degradation over a number of yea rs have led to w idespread support from the community and key stakeholders for water reform.

In recognition of the importance of managing wa ter effectively, all Australian governments - Commonwealth , State and Territory - committed themselves to a package of reforms w hich is pathbreaking in some imp ortant respects . All jurisdi ctions are now moving on a common front to improve Australia's wa ter industry and rem edy environmental damage.

This collective approach towards reform is more likely to succeed than individual, unco ordinated approaches. It is necessary for dea ling w ith waterways flo w ing thro ugh more than one jurisdictio n. T he joint management by fo ur of the Australian States of the water, land and environmental

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Other important adva ntages are the opportunities fo r wa ter authorities and providers from different jurisdi ctions to learn from one another through the exchange of co mmercial and scientific information on issues they face in common and through benchmarking.

T he reforms encompass all aspects of the w ater industry and its environmental impacts . They are ambitious and complex, but their implementation is mostly on track and good results are already being achieved.

For instance: • Proper pricing fo r wate r (including charging according to consumption) has introdu ced an incenti ve fo r effi ciency in water usage and equity bet\;veen consumers of water. Consumption of wa ter in

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INNOVATION Brisbane fell 20 per cent with the introduction of C\¥0-part tariff pricing, and water bills in urban areas nationally fe ll by nearly 9 per cent in 1998 and 1999 beca use of lower consumption and prices.

• Beca use new inves tment needs to be eco nomica ll y viabl e and ec ologically sustainable , the gu aliry , effi ciency and produ ctivity of Australia's water infrastru cture will be enhanced over time.

• Allocations of water for the environment are now recognised in governments' legislation and are being n1.ade, so helping to increase biodiversiry, improve habitats, effect visual improvements to waterways, and enhance tourism and recreational facilities.

On_e of Australia 's most beautiful and iconic rivers - the Snowy - is being rehabilitated through the restoration of water flows.

• The roles of water resource management, standard setting and regulation, and service provision are being separated and unde1taken by different agencies . The resulting clarification of roles and responsibilities allows water providers to fo cus on their business and not face conflicting objectives or unclear goals, and there is better regulation by specialised and professional regulators.

• The effi cient operation of suppliers is leading to lower pri ces than otherwise, better service and more prod uctive use of assets. The cost of urban water supply has

BUSINESS

fallen by 19 per cent over the past six years.

• Rural water users are benefiting from the reforms. T he separation of wa ter ti tle from land title and th e clear specification of title (including through the establishment of registers of water entitlements) will create for farmers a bankable and tradeable asset.

Water trading is increasing agricultural o utput as water enti tlements flow to their highest value uses. Trading gives irrigators more options for their businesses and greater fl exibiliry w ith farming practi ces and crop choice. It also allows new industries to secure the water they need to undertake investment. Trading is increasing and in som e areas up to 17 per cent of allocations are traded o n a tempora1y basis.

• Governments are condu cting public educa tion campaigns. A better informed public on water issues and on the need for and benefits from reform means easier and more co mpl ete implementation of the water reform framework . Governments' consultations with key stakeholders on proposals for reform s are produ cing better and more widely accepted poli cy choices .

A unique feature of the reforms is their holisti c nature . They a re mutu ally reinforcing; fo r instance, allocations of water for the environment ensure sustainable river sys t ems which, in turn , e nh a n ce consumptive ri ghts in the long run, including throu gh better water qu aliry and

improved securiry of supply. The resulting support for rural output contributes to Australia's GDP growth in the long term.

The reforms are part of a broad package of competition-enhancing reforni.s to which Australian governments have committed and which they are actively impl ementing.

In recognition of the reforms' contribution to economic growth, the Commonwealth makes substantial payments each year to the State and Territo1y go~ernments, which may be withhe ld in p art for noncompliance with their commitments.

T he N ational Competition Council' s role is to help and advise Australian governments on the implementation of the National Competition Policy reforms, including those affecting the water indust1y.

Water reform is one of the most demanding of the many reform conu1i.itments accepted

by Australian governments, but also one of the m ost rewarding in terms of economic a nd e nvironm e ntal outcomes from successful implementation. The far reacli.ing nature of the reforms places Australia in the vanguard of the international movement to establish better water industries .

The Author Graeme Samuel is President of the National Competition ouncil.

WATER MARCH 2 00 2

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A REVOLUTION IN PVC PRESSURE PIPE P Chrystie Supermain Oriented Poly Vinyl Chloride (PVC-O) orients the molecular structure in the direction of major operating stress, is twice as strong as PVC and has improved mechanical strength, fracture behaviour and fatigue resistance.

Supermain has been used since the 1980s, but a novel iii-line mamifacturing process has been conceived and established through theoretical and experimental studies at Vinidex sites throughout Australia.

Extensive development work was undertaken throughout the 1980's and 1990's and during 1998 the in-line plant became operational.

PVC ¡ Some History Unplasticised Poly Vinyl Chloride formerly known as uPVC and now abbre-

viated to PVC was first develop ed in the 1930's and came to be used in pressure pipelines from the 1950's, fi rstly in E urope, then the United States with Australia following in the 1960's. The product has now developed to a mature status with kno w n and respected performance history in pipeline applications, due to its many adva ntages including corrosion resistance , light weight and hydraulic effi cien cy .

The ability to enhance the physical and mechanical pro perties of plas tics is evident on many of m odern plastics appli cati ons, a couple o f common examples being the incredibly strong sh opping bags and soft drink bottles.

Prop erty enhancement came to PVC pressure pipe in the form of oriented

p olyvinyl chloride,.. (PVC- O ) in the Vinidex tradename Supermain .

Supermain Oriented Poly Vinyl Chloride (PVC-0) Supermain PVC- O pressure pipe 1s manufac tured to AS 4441 (Int): 1996. An international standard in which Vinidex is a maj or contributor is currently being develop ed .

Sup ermain PVC -O is manufac tured by expanding PVC feedstock pipe in the circumferential and longitudinal directions, thus orienting the m olec ular structure in both the circumferential and longitudinal directions. As the maj or stresses in pressure pip es op erate in the circumferential direction, orientation puts the material strength w here the stresses are. The result is chat Sup ermain PVC-O is approxim~tely twice as strong as PVC enabling a pipe of about half the w all thickness for the same pressure rating.

Initially, in the 1980s, an off-line process for PVC-O had been developed where cut lengths of pipe w ere expanded and then oriented in a mould in a tw o stage process . This method w as slow and inefficient.

Supermain Innovation An in-line manufacturing process for Supermain PVC- O is was conceived and established through theoretical and experimental studies at Vinidex sites throughout Australia. Extensive development work was undertaken throughout the 1980's and 1990' s, during 1998 the in-line plant became operational. The in-line pro cess brings greater effici en cies in materials processing and output. Success in this endeavour h as placed Vinidex as the w orld leader in this area and has revolutionised PVC pipe products.

Vinidex holds six patent families, extending to over eighty patents and patent applications around the world, fo r PVC- O technolo gy, dem ons trating " ownership " of PVC-O development.

Supermain PVC -O pressure pipe is now regarded internationally as the best performing PVC pipeline for pressure appli cations. Vinid ex developmental experts are continually requ ested to

INNOVATION

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Vinidex Profile

deli ve r technical pap ers on PVC-0 technology at international industry fo rums.

With th e global pip eline industry recogn isin g th e advantages of Supermain PVC-0, Vinidex has already developed a strategic alliance w ith the m aj o r European plas tics produ cer Uponor and is now receiving offers for joint ve nture opportunities overseas with the PVC0 technology .

Supermain Advantages Sup ermain has the following advantages compared to other water reticulation pipelines: • Increased flow capacity , • Higher impact strength , • Greater fatigue resistance, • Higher tou ghness, • Greater tolerance to damage, • Corrosion resistance, • M aterial and energy efficient - environm entally more sustainable, • Supermain PVC- 0 virtually retains the same safety factor as traditio nal PVC ,

• R elative lightweight and long lengths provide efficiencies in installation, • Less material requires less energy to m anu fac ture, transport and handle.

Supermain PV C- 0 pipes ha ving already established a record of successful installations in wa ter supply projects throughout Australia, with many water authoriti es m akin g it th eir pip eline m aterial of choice.

Vinidex Pty. Ltd. is a leading m anufacturer and distributor of thermoplastic pipe and fitting systems for the transportation of fluids, energy and data for infrastructure development, agric ulture, mining and building. With a forty year history in Australia, Vinidex has developed a strong ·eputation in the water and related infrastructure industries .

Vinidex has production and distribution plants throughout Australia and a significant m anufa cturing presence in the Asia-Pacific Region.

As a national and international leader in the thermoplastic pipe and fitting industry, Vinidex will continue to develop new produ cts, pro cesses and testing techniqu es that will ensure a continued prominent position on the world stage.

The Author Peter Chrystie is N ational Business D eve lo pm e nt M a n age r / Water for Vinidex. T el 61 2 9604 2422. Email: pchrystie@vinidex.com.au

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A SIMPLE AND COST-EFFECTIVE SPILLWAY DESIGN/REVIEW TOOL FOR FARM DAM OWNERS J D Pisaniello, J M McKay This article reports on atl innovative costeffective spillway design/review proced11re developed for farmers in So11th Eastem A11stralia, but which is traniferrable to any other region worldwide. Dam safety policy models and guidelines for aiding Govemment decision-making are also provided. The procedure is quick and simple to use, yet is based on modem best practice, which is critical for avoiding legal liability. The procedure minimises cost burdens to dam owners, encourages better dam safety management and provides an acceptable level of safety assurance to downstream communities.

Introduction While failures of large dam s are ge nerally more spectac ular than those of smaller dams and receive mu ch more attention, smaJl dam failures, particularly those of privately-owned farm dams, occur far more fr equently. Therefore the total annual cost of small dam failures can be more serious than the rare failures of large dams, especially in relation to governme nt owned infra -s tructure.

Failures of relatively small dams have sometimes had disastrous consequences.

In the United States, for example, a 19111 high earth dam failed in Pennsylvania in

1889 leading to the d estru ction of J ohnstown and killing aro und 3000 people , (Sowers, 1974); the Kelly B arnes Lake dam in Georgia, only 8111 high, failed in 1977 killing a total of 39 peopl e; and th e Lake Lawn dam in Colorado, w hich was also 8111 high and stored only 830 ML, fai led in 1982 drowning 3 people and causing US$31 million in damage despite warnings and evac uation (Hiser & M cDonald, 1989).

Following th e fa ilure of the Kelly Barnes Lake dam Presid ent Ca rte r co1111nissioned an inve ntory of dams on safery issues. Of 68,000 dams surveyed 8,800 we re deem ed to be ' high ' haza rd dams. Of these, 2,900 were rated as unsafe, with 2,370 unsafe because of inadequate spillway capaciry (US D ept. of Interior, 1980).

These past events suggest that without appropriate design , construction and maintenance, poorly managed small dams can cause significant human and properry losses to the community . R esearch has shown that overtopping as a res ult of inadequate spillway capaciry is one of the main causes of dam failure, representing approximately 40% of all recorded failures wo rld-wide. Furthermore, embankment

dams are most vulnerable to failure by overtopping, representing 70% of cases where dam s have fa iled under fl ood (AN COLD , 1995) . This is of parti cular relevan ce to small dams, as the m ajority of th ese dams are embankment-type constru ction .

Australia has a large numb er of relatively small , privately-owned dams (fa rm dams in particular): those which have fa iled number in the thousands. For exa mpl e, Vi ctoria has an estimated 170,000 fa rm dams, 800 of which are large enou gh to ca use seriou s consequences downstream if they failed, while in NSW, a recent study by the Australian National Committee on Large D ams revealed a 23% fa ilure rate for the State's farm dam s (ANC OLD , 1992) . One of the main concerns is that most owners hire earth- mo ving contractors to constru ct their d am s. Thes e contra ctors are, rypically, not properly trained or skilled in the des ign and constru ction of dams.

Also, the majority of dams were built more than 20 years ago, so even " proper" designs could only have been based on information and criteria available and relevant at the time: many aspects have changed ove r time.

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that studies of dams should (1) Mo st pri va t e dam s ar e consider all releva nt aspects so relatively sm all in size, and that obj ective decisions ca n be represent a " Low" hazard to based on real impacts for the their immediate downstrea m overall benefit of the society and inundation area. Unfortunately, (2) present alternatives and ho weve r, when these dams are discuss as early as possible all the considered cumulatively in a positive and negative effects large catchment of, say, a large, with interested parties, including hazardo us public reservoir, they the persons directly effe cted by eac h represe nt a significa nt .c the dam. incre m ental flood hazard as their cumulative failure can Dam safety management Figure 1. A typica l spillway as previ o us ly built, with th e increase signifi cantl y the risk of black out li ne demonstrati ng t he size th at it should be if it in Australia failure (via the " dom.ino effect") was des igned prope rl y.

Althou gh all government of t h e p u bli c r ese r vo ir dams in Australia are adeq uately level of ass urance policy that is 'approdownstrea m. Th e effect of audited, the risks of small privately-owned priate' for va rying circumstances . additional flooding in the connecting river dams persist. systems can also be severe, as was demonPri va te owners tend to neglect the Since 1972 ANC OLD has prepared strated in a recent flood study of the need for reviewin g their dams beca use of guidelines for dam safety legislation, and Kangaroo C reek Dam in th e Torrens the high cost of professional advice and propo se d t h at eac h Stat e sh o ul d instead develop a sense of complacency, catchment of South Australia. implement such legislati on w ith an believing that as the dams have not failed These risks have been recognised by independent control authority. Virtually up to now, then they will never fail. T he Governments; unfortunately, dam safety all of the State Governments have result is that dams are deprived of attempted to act upon these concerns by legislation is often consi dered too necessary upgrading and downstream 'extreme ' and ac tion rarely follows , presenting 'Dam Safety Bills' to their communities are placed at risk. largely because of the significant cost respective parliaments . Unfortuna tely, burdens upon both Government and T he International Water R esources due to a high level of political ambivaAssociation and Third World Centre for pri va te owners. Also, th ere are no lence, attempts to ena ct these Bills have systematic guidelines to determining the Water M anage m ent recently id entified not been successful in all States .

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INNOVATION

To date , only three of the six States and two Territories have been successfu l in establishing sound statuto1y control over dam managem ent, as demonstrated

by P isa niello and McKay (1998a).

H owever, while Queensland and Victoria have incorporated workable dam safety provisions within existing sta tutes, NSW is the only State to implement a specific dam safety A c t und e r w hi c h an independent dam safety enforcement committee is constituted . (Pisaniello & M cKay, 1996) .

BUSINESS

Fundamentally, it is necessa1y to edu cate priva te dam owners to realise their responsibilities and liabilities in acco rdance with the dictates of common law, and also to establish some form of regulato1y control over dam m anagement practices to ensure that owners appropriately manage their dams in line with current standards . Pisaniello and McKay (1998a & 19986) indicate that this can be best achieved w ith the establishment of properly organised, systematic dam safety programs based on dam safety legislation.

At the ve ry least, co nsidering that downstream communities ultimately bear the risks associated w ith darns , they should have the "right to know" the potential dangers they are living under and be provided w ith the opportunity for salvation in the event of failure though appropriate Emergency Preparedness Procedures provided for under legislation.

Three safety assurance policy models have been developed w hich can be implemented in any Country or State: a model of"best practice", one of"average prac tice" and a model of " minimum practice " (see Pisaniello & McKay, 1998a, for a detailed description of these models). T hese models represent "appropriate" practice for the entire range of varying circumstances.

International best practice The dam safety m anagem ent and ass urance practices of a number of co untri es including Australia, U SA, Canada, United Kin gdom, Finland, Portugal, South Africa and N ew Zealand we re reviewed by Pisaniello (1997) and Pisaniello & M cKay (1998a). The schemes used to control dam safety management vary w idely within and between countries. However key components in certain practices can be identified.

These components generally include: (1) federal involve m ent, (2) legislation, (3) administration, (4) staff education and training, (5) registration and classification of the dams, (6) su rve illan ce and inspection, (7) spillway design flood capability standards , (8) community education and preparedness, (9) owner responsibility, (10) punitive enforcement and (11) owner education and guidance.

These components have been analysed to identify examples of" better" practice, which in turn have been used to develop detailed policy models, guidelines and criteria for determining "appropriate" safety assurance policy for any jurisdiction, as discussed below.

Flood capability design/review procedure To encourage private darn owners to review and upgrade their spillways to meet current acceptable standards, a simple and cost-effective flood capability d esign / review proc e d u r e has b ee n develop ed which is applicable in South Eastern Australia, but transferable to any

other region. It is in line with cmTent best practice, thereby promoting consistency and uniform standards. The mechanism uses regionalised relationships based on simple hydrological/hydraulic variables for predicting reservoir flood capability as ei th er 1/ AEP or % PMF: The procedure is applicable to reservoirs on small rural-type catchments (up to around 15 km2), · compatible w ith any design flood standards, and is based on easily derived variables only, (i. e. spillway w id t h an d h e ight , rese rvoir area, catchment area), making it quick to use ye t accurate in the output it provides.

Pisaniello (1997) and Pisaniello et al (1999) provide full details of how to apply the procedure in any other region.

A public information brochure was recently developed in South Australia for promoting the m echanism , and also demonstrates the simple application of the procedure. Figure 1 illustrates the impact of proper design.

The procedure was recently transferred to the Australian States of NSW and Victoria in research projects funded by the Rural Industries Research and D evelopment Corporation (RIRD C), the NSW Department of Land and Water Conservation and the Victorian D epartment of Natural R esources and Environment (Pisaniello & M cKay, 1999).

The m ain benefit of the m echanism is its simplicity w hich dramatically reduces the great effort and resources that are normally required for condu cting a state-of-the-art reservoir flood capability evaluation and/ or design. For example, the consultant fee for undertaking such an evaluation and/ or d esign for an

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embankment dam on a relatively small catchment is nonnally around AU 10,000.

The d evelop ed mechanism h as th e potential for reducing this fee to aro und AU$500.

Conclusion There is a clear need to ensure that owners review and maintain their dams in line with current acceptable practice and take appropriate remedial ac tion where necessary. T he implementation of appropriate policy requires the backing of law-make rs. The policy models and exploration guidelines and cost-effective regionalised procedure reported in this paper should encourage such backing.

A simple and cost-effective regionalised flood capability design/ review mechanism wo uld minimise cost burdens to private owners, provide the basis for quick ye t accurate review and/ or design of private dam spillways, and if in line with modern acceptable practice wo uld be of critical importance in a court of law .

This schem e would complete the water law and policy regulatory scheme in any jurisdiction and promote better water planning, looking at all aspects of the cycle of dams and their role in the community of economic, ecological and social interests .

Acknowledgments The authors acknowledge the Rural Industries R esearch and Development Corporation (R IRDC) , th e NSW Department of Land an d Water

BUSINESS

Conservation (DLWC) and the Victorian Department of N atural Resources and Environment (DNRE) for their cofund ing support of the research project to transfer th e Pisaniello (1997) spillway design/ review procedure to the Australian States of NSW and Victoria. Special thanks to Mr George Wilson (RIRDC), Mr Siraj Perera (DNRE) and Mr Ross Barrie (DLWC) for their interest in the resea rch and valu able contributions.

Thanks also to the Australian Research Council for agreeing to fund further development via a "community partnerships" approach .

References AN OLD 1992. Status of Dam Safety in Australia, Bulletin o .91: 9-29.

ANCOLD 1995. C11idelines on Design Floods for Dams, First Draft only, October 1995. Dam Safety Act 1978 (NSW) Hiser, W . & M cDonald, L. 1989. D am Safety, Water Supply a11d R esources conj. proc., Nov. 1988, Sydney, NSW: 163- 171.

Pisa ni ello, J. D. & M cKay, J. 1996. Legislation Imposition of Adequate Private Dam Safety Assurance, The A 1-1stralia11 Journal of E111ergency i\lla11age /lle11t , Emergency M an age m ent Australia, Vol. 11 , No. 1: 9-12.

Pisa ni ello , J.D. 1997. A nalysis and Modelling of

Private Dam Safety A ssurance Policy and Flood Capability Design/ R eview Procedures, PhD Thesis, University of So uth Australia.

Pisa niello, j.D . & M cKay, J.M. 1998a. Models of Appropriate Practice in Private D am Safety Assurance , Water Policy, World W ater Council Journal, Elsevier Science Ltd, Vol 1, No 5: 525- 550.

Pisaniello, J.D. & M cKay,J.M. 19986. The eed for Private D am Safety Assurance Poli cy - A D emonstrative Case Study, Th e Austra lia11 Joumal of Emergency i\l[a11agement, EMA, Vol. 13, No. 3: 46-49.

Pi sa ni ell o, J.D. & M cKa y, J .M. 1999.

D evelopment of a Cos t-effecti ve Flo od Capability D esign/ R eview Procedure for Small D ams in Vi cto ri a, Technica l R eport for DN RE, U ni SA, R ef No. 0566794-1.

Pisa niello, J.D. , Argue, J.R.. & McKay , J.M .

1999. Flood Capab ility D esign/ Review of D ams on Small Ca tchments - A Simple and Cost-effec ti ve Regionalised Pro cedure, Australian J ournal of l,Vater R esources, lEAust, Vol. 3, No. 2: 177-188.

Sowers, G. F. 1974. 'D am Safety Legislation A Solution or a Problem', Sefety ef S111all Da111s Conference, New H ampshire, 4-9 August, 1974, pp . 65-100.

U S D epartment of Interior 1989. Policy a11d

Procedures for Da111 Safety Modification Decision111aking, B ureau of R eclamation Document, April 1989, Section 3, Part III , pp. 23-60.

The Authors Dr John D. Pisaniello is a R esearch Fellow & Director E ngineering Law Research of the Water Policy and Law Gro up at the School of Internatio nal Business , University of'South Australia , North T ee, Adelaide, SA, 5000 (Email: J ohn.Pisaniello@unisa .edu.a u. Jennifer M. McKay is a Professor of Business Law and also Director of the Water Policy and Law Group, University of South Australia (Email: J ennifer.McKay@ unisa .edu.au , we bsite: www.b usiness. unisa .edu .a u / waterpolicylaw

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ASSET MANAGEMENT OF SYDNEY WATER'S SEWERAGE SYSTEMS

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I Garside, S Hall Since July 1999, SWC and Montgomery Watson Harz a (MWH) have been developing and using innovative p lanning sy stem s and processes to determine solutions and capital expenditure priorities for meeting the long-term f11t11re needs of SWC's sewerage infrastructure. Part of this work was the development of a series of processes that describe how to develop a SCAMP (Sewerage Catchment Asset Management Plan). Underpinning these processes was the collaborative development of integrating software known as OACIS.

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Background Sydney Water C orporation (SWC) provides sewerage services to almost four milli on c u stome rs ac ro ss Sy dn ey, Illawarra, and th e Blu e Mountains maintainin g 27 sewe rage sys te m s consisting of some 22, 000 kilometres of sewe r s ( Fi g 1 ) . An ex t e n s i ve Figure 1. Map of Sydney Metropolitan area En v ironm e nta l I mpa c t Sta t e m e nt program undertaken by SWC during the standardised and semi-automated system late 1990 's estimated that an AUD$2 analysis tool OAC IS bi lli on , 2 0 -ye ar sewe r ove rflo w abatem ent program was required to The SCAMP Process rec tify the problems in SWC's sewerage T here are three stages to th e develsystems. SW C had a numb er of broadopn1ent of each Sewerage C atchment scale decision support tools to measure Asset M anagem ent Plan (Figure 2) : system performance and indicate areas of required remedial activity, h ow ever THE FIRST STAGE consists of there we re no procedu res in place to gathering all existing sewerage catchment allow SW C to expedite the investigation, data, including asset netw ork data (pipes , and to compre h e n sively plan and access ch amb e rs, sewage pumpin g prioritise the sewerage system impro vestations, constru cted ove rflo ws, other ments required to meet licence conditions ancilla1y structures) , individual properties regulated by the N ew South W ales with historical wa ter consumption data, Environment Protection Authority . census populations, trade waste contributors, and op erational " incident" data SWC and MWH have to ge ther including chokes, odours, and m anhole develop ed the Sewerage C atchment Asset M anagem ent Plan (SCAMP) process . To date, the process has been initiated for approximately 70 catchments, serving over 1.2 million customers within SWC 's area of operatio ns, with an ultimate target of 240 catchments, serving 3. 9 million customers in total. Su ch an ambitio u s pro gram w ou ld b e difficult w ithout the effi ciency gains ac hi eve d by u sing th e Figure 2. Stages of SCAMP Process

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from 0AC IS

surcharges . The data is drawn from a series of disparate databases and geolocated into GIS fo rmat for ease of analysis. In addition to the abo ve, rainfall, sewer flo w, depth, and velo city data are collected. All data goes through a series of quality ch ecks and reviews to ensure it is su ffici ently accurate fo r planning purposes .

In order to p ermit the acc urate prediction of existing and future flo w scen ario s, a d etail ed comp ut erise d hydraulic model is then developed and its predictions validated against the collected flo w and rainfall data. The hydraulic model allows the planning engineer to understand exactly the fate of flo w s in the system under both diy and wet w eather conditions, and most importantly can be used to determine the causes of overflo ws from the sew er netw ork w hich cause public health and environm ental concerns. In parallel w ith this, a screening level assessm ent of the environmental and community iss ues withi n the catchment is undertaken. T his exercise seeks to

INNOVATION

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involve all affected stakeholders in up to date information. As with all innovative processes, the the system improvement process at the earliest po sible stage. Th e OACIS tool and SCAMP assessment identifi es all sensitive pro cess i s und ergo in g sites and issues that may be either continuous improvement. direc tl y impa cted by sewage The main outputs from the overflow discharges, or indirectly SCAMP process are reports impa cted by potential system documenting the three main improvement options , th ereby study phases : allowing certain courses of action Data Int egration & to be precluded during the subseInterpretation (Model Build quent options development stage . and Validation) Such issues, if not discovered at an Figure 3.The Components of 0AC IS â&#x20AC;˘ N eeds Assessment early planning stage, have been â&#x20AC;˘ Options Analysis known to manifest later during These reports, including associated draw ings, are produced construction phases to disrupt capital expenditure projects and in a paperless format, accessed through OACIS using Internet cause unnecessary co mmunity disaffe ction. browser technology (Figure 4). Accompanying each report are THE SECOND STAGE involves using the data gathered electronic ve rsions of the procedural documents or guides earlier to determine whether the current and/ or the predicted relevant to the study process. The paperless reporter also displays future pe1formance of the sewer network satisfies SW C's objecthe status of the quality assurance ve rification plan completed tives or the terms of their operating and environment for each individual catchment study . protection licences . Extra flows resulting from future growth are estimated for the 5-year and 20-year planning horizo ns, using population and development projections from State and Local Government planning data. Where there are deficiencies against desired performance objectives, a need for investment or revenue expenditure is identified and quantified. This second stage is undertaken as an integrated exercise involving system planning engineers, operations and maintenance personnel, and environmental and communi ty specialists, ensuring that all internal stakeholders are aware of the identified problems and iss ues, promoting own ership of the problems and issues, facilitating appropriate prioritisation of subsequent improvement works and leading to a balanced approach for the development of holistic Mining ~ solutions.

Construction Sound Meters Conf'med Space Entry THE TH IRD STAGE develops cost-effective sewerage improvement options to alleviate the identified system Long Te1m Logging problems, taking into account any environmental, communi ty, or operational constraints identified ea rlier. Options ma y be developed in conjunction with community working groups to achieve universally acceptable solutions. This final stage results Single Gas Detectors in a report containing fu lly costed ca pital works recommenHeat Stress dations, with summarised versions for external community Noise Dosinietry co nsultation purposes and internal business case approvals.

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What is OACIS? OACIS (O verflow Abatement Co mputer Information System) was developed to provide a tool for effi ciently conducting system planning studies at the detailed level required for comprehensive sewer catchment asset management planning.

The OACIS tool is a so ft wa re platform that integrates and interrogates SWC's numerous data so urces relevant to the SCAMP planning process. OAC IS provides the vehicle for undertaking the planning studies, utilising a paperless syste m of recording data changes, data interpretation and quality checks, ensuring that the SCAMP process is consistentl y adhered to .

Uniqu ely, OACIS provides direct access and links to the base asse t data, flow data, interpretive so ftware, and the hydraulic model engine. This required collaborative wo rk betwee n the suppliers of the major so ftware components to ensure that all the tools and data required to undertake a SCAMP study ca n be accessed through a sin gle interface. Figure 3 provid es a diagrammatic representation of the OACIS components.

OACIS is able to access relevant data for the S AMP studies directly from SWC's live databases allowing access to the most

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INNOVATION

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OACIS use s GIS technology to provide the primary user interface, to permit display of layers of spatial information such as hi s tori ca l in c id e nt s, network asset information, co ntour an d ca d astra l informatio n, and land use info rmation (Figure 4) .

Presentation of data in a spatial manner allows rapid integration of data sets on different layers and provides a usefu l mechanism for the produ c ti on of bot h wo rkin g drawin gs and report figures.

The OAC IS softw are Figure 4. Sewerage Network Di splay in 0ACIS tool and the associated SCAMP processes represent Latest Developments world's best prac tice in advanced asse t The software and associated processes management, wi th elements sourced were initially completed in June 2000, from the UK, USA and mainland Europe. including a six month period to beta test The OACIS tool and processes were the systems on pilot studies, during collaboratively developed in SWC' s w hich time a software programmer was offices to ensure that their purposes were retained as part of the core team to ensure adequately served. that the results were reincorporated into ,i90 ... l ,2S0,050i.

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the OACIS software .

Since then , muc h work has been done to iron out anomalies in t he software and processes and devise more efficient methods.

Studies have been initiated on approxim ately 70 individu al SCAMP areas, out of a total of 240 catchments, wi th up wards of 60 professionals wi thin SWC and ex t e rn a l consultants trained in the system . This has req uired a dedicated fu ll time engineer, to train the users and ensure that the do c um e nt e d q u ality sys tem is effe c tiv ely applied , ensuring that completed wo rk is acceptable and consistent.

OACIS has had a significant impact and is now being used for other purposes within SWC. For example, all 27 broadscale strategic models that were developed

by SWC in th e 1990's have been uploaded into the OACIS format and are undergoing a re-validation and updating process for reporting purposes.

Latest developments involve updating the SCAMP planning process to incorporate a greater degree of community consultation, as well as integration across the organisation's internal stakeholders.

SWC is also planning to upgrade the OACIS software in line with new releases of the hydraulic modelling engine, and to incorporate enhancem ents designed to provide further efficiency gains associated w ith data pro cessing, such as simulation and analysis ofl ong term time series model runs.

Work is c urrently underway to streamline the options development and analysis stage incorporating wo rld's best prac tice whe re applicable, to ensure th e best o utcome for SWC and its customers in tem1S of not only cost, but also environmental and community o utcom es .

MWH acknowledge Sydney W aters' permission to publish this article.

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Steve Hall is Project Manager for MWH's SCAMP projects and was in the OAC IS development team. Co ntact : ian .garside@m w hglobal. com or visit MWH 's we b site at http: // www. mw hglobal. com

INNOVATION:

BUSINESS

LIFE CYCLE ASSESSMENT IN A MAJOR WATER AUTHORITY G Peters Sydney Water is Australia's largest water a11thority serving a pop11la tion of 4 million. It relies on many p lanning tools and performance indicators in its p11rs11it of BSD. Life cycle assessment is being 11sed to co·mpare alternatives for strategic p lanning p11rposes.

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Recent uses in Sydney Water Sydney W ater recognises the valu e of LC A in the strategic planning process, and has adopted it in several recent proj ects. Spoil disposal options for th e N orthsid e Storage Tunnel were assessed using LCA (Sydney Water, 1997) .

This initial public LCA covered energy use and greenhouse gas emissions. Partnership w ith University ofNSW researchers biosolids enabled a subsequ ent LC A of biosolids handling alternatives to ex amin e th ese imp ac t categories and'the potential for effects on human health. This study is summarised in the next section. More recently, alternative m eans of eilluent disinfec tion and the relative m erits of anaerobic and ae robic sludge digestion have been examined in terms of nine different impact categories (B eavis and Lundie, 2002). As part of a review of its long-term strategic infrastructure planning document "WaterPlan 21", Sydney W ater is currently undertaking its largest LCA proj ect to date, assessing its entire business in order to understand w here its most significant environmental issues will be in 202 1, and w here its improvem ent efforts should be fo cussed.

Example: LCA of biosolids options Environmental issues addressed in this LCA were energy consumption, greenhouse gas emissions (global warming potential) and potential toxic effects in humans . (For more detail see P eters and Lundie, 2002). T w o comparisons were draw n : • configurational (the curn; nt decentralised system versus a possible centralised system w ith one plant to treat biosolids fr om Sydney Water's major coas tal plants); and • technological (thermal drying versus lime amendment at North H ead STP).

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INNOVATION

In the configurational comparison, the centralised system would use significantly (47%) more energy than the decentralised system. However, this was a consequence of the choice of drying technology (using petrochemical methane) in the centralised sy stem instead of lime amendment, w hich is used in the current decentralised system . The energy required to pump biosolids to a central plant was relatively insig nifi ca nt. The global wa rming and human toxicity potentials of the different options did not differ significantly, on acco unt of the change in the energy supply 111.ix from electricity to natural gas .

In contrast to that assessme nt, the comparison of technology choices for North H ead STP showed significant differences between the options. The availability of endogeno us biogas in the drying option for the STP allowed a 60% reduction in energy consumpti on and a 34% reduction in green h o u se gas emissions relative to lime amendment (see Figure 1). Selection of this drying option wo uld result in a 20% improvement in human toxicity potential compared wi th lime amendment.

The key issue in improving the e n vironme ntal p rofile of bio solid s handling is the avoidance of coal-sourced electrical energy. R enewable fuels such as biogas, and cleaner fuels, such as natural gas, will improve the environmental performance both by reducing the carbon- intensity of energy use, and the toxicity of emission byproducts . T he next most important goal is reducing the energy required for trucking biosolids by reducing their moisture content and/ or the distance to the delivery site.

Conclusion LCA provid es uniqu e insights in strategic planning fo r Sydney Water because it considers diverse enviromnental impacts related to waste water treatment systems and processes and presents the different contributors to a particular type of environmental problem on a common basis. Available process data , impact models and software are adequate for LCA. Since environmental impacts are taken into account wheth er they occur on or off site, this holistic , strategic approach prevents 'problem shifting', that is, the transfer of environmental problems from one part of the environment or the supply chain to anoth er.

LCA is being used to improve "life cycle thinking " in Sydne y Water's

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Comparison of indicators used by Sydney Water Life cycle costing (LCC)

LCC differs fundamentally from LCA in that the basic units of LCC are financ ial while those in LCA are physical .

Sydney Water has benefited from LCC analysis of parts of its business. Attempts in som e quarters to include environmental effects ("externalities") in financial decision- making (contingency valuation, willingness-to-pay etc) generally run th e risk of blending such subjective measures into otherwise rigoro us processes.

Therefore, LCC does not generally discuss environm ental impacts nor the relative sustainability of the object being analysed, although developments in this direction using physical m easures of greenhouse gas em.issions, which wo uld begin to m erge th e two m ethodologies, are being made (see T ucker et al., 2000) .

Ecological footprint ( EF)

Sydney Water publicly reports on a myriad of different operational environmental p ara meters at different levels of ge n e ralit y, from t h e m ass of 4methylphenol emitted by individual STPs, to the greenhouse gas emissions ca used by the organisation. In an attempt to meaningfully aggregate impacts , Sydney Water is exami ning the EF methodology, w hich gives results w hi ch are easy to visualise and communicate w ith a wide audience (Sydney Water, 2001). However, it is difficult to transfer EF into the design process or to use it to consider emissions to aquatic ecosystems. Therefore, Sydney Water has employed it as a reporting too l rather than a planning tool like LCA .

Value management studies (VMS)

VMS ge n e rall y in vo lves la rg e meetings at w hich views of a wide range of stakehold ers in the community,

strategic planning activities, taking into account the entire lifespan of a plant, and the other processes in its supply chain .

This is essential for proper comparison of the ecological sustainability of developments . It should be expected that LCA will be an important part of the planning pro cess for other water authorities .

The Author Gregory Peters is an environmental engineer with Sydney Water and has a doctorate in environmental chemistry. H e has performed several LC As and is responsible for the LCA ofWaterPlan 21 currently underway.

government and indu stries are aired, often as a preliminary step in the E IA process. VMS o utput is qualitative usuall y including a list of ideas generated, actions and further information to be ga thered.

Environmental risk analysis (ERA)

Sydney Water has been a pioneer of this type of environmental assessment. As a consequence of the Sydney Water Act 1994, the Company cond ucted four regional ERAs on certain chemicals (Schedule 10 of the Act) discharged from its sewage trea tment plants. T his extensive programme of monitoring, expos ure modelling and eva lu ation ena bled SWC to prioritise particular contaminants for pollution redu ction programs. There is much synergistic value to be derived from connecting the ERA process with LCA. This is cun-ently one of the focuses of academic research in LCA m ethodology.

Environmental impact assessment (EIA)

EIA is a well-established methodology for exami ning the env ironmental impacts of new developments. lt incorporates a wide range of environmental issues and involves a high degree of public participatio n. An EIA is usually focussed on the development site, differentiating it from classical LCA, which is more concerned with regional and global environmental issues and in indirect offsite emissions.

A s stated in !SO14042, EIA, ERA and LCA "are not s11bstit11tes for one a11other" but ca11 complement one another. For example, LCA may ide11tify a preferable i11d11strial process 111hich cal! th e11 be checked for site suitability 111ith EIA and ERA. 0

References Beavis P and Lundi e L (2002) Integrated En viro nmental Assessment of T ertiary and R es idu als Tr ea tm e nt - LC A in th e W astewater Indu stry. Proceedi11gs of E1111iro 2002, IWA World Water Co11gress, Melbo11l'lle, 8-1 ¡1 April.

Peters G M and Lundi e S (2002) Li fe -Cycle Assessment ofBiosoli ds Processin g Options, J o11 mal of fod11strial Ecology, 5(2) 103- 121.

Sydney W ater (1997) N orchside Storage Tunnel Spoil Disposal Options Life tycle Assessment.

NSST EIS Appendi ces Volum e 1.

Sydney Water (2001 ) Towards Sustainabi lity 200 1. w ww .sy dn eyw at e r. c om. a u / html/ tsr/i ndex.html accessed Janu a1y 2002 .

Tu cker S N , Mitchell V G, Burn L S (2000) Li fe Cycle Costin g of Urban W ater Systems.

Water, volume 5, pl 2.

INNOVATION:

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DERCETO: AN ONLINE PUMP SCHEDULE OPTIMISATION SYSTEM J Wardle, S Bunn A 12 to 15% red11ction in water p11mping costs is being achieved by a new pump sched11ling optimisation system, developed in New Z ealand, now being applied in Australia, with Beca-Simons having just been appointed for its implementation by one of A ustralia's leading water authorities.

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D erceto supplies w ater from the lowest cost source based on fix ed or m easured chemical and power costs.

Pumping is scheduled to minimise costs. Powe r costs include both 7'Dem netwo rk and energy charges. Three quarters of the pow er costs for the WRC system are for th e W aterl oo bore-field WTP. Energy charges are a two-tariff per day structure w ith diffe rent rates fo r weekends and wee kdays w here the tariffs change eve1y month for each pumping station and WTP. Ifin the future the cost structure is altered, D erceto can handle half- hourly power tariff changes for each point of supply. The low tariff period (night tariff) is from midrught to 8am. For

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Developed by Beca Technologies of NZ, and introdu ced by th e Australian engineering consulting company Beca Simons Pty Ltd, Figure 1 .

DERCETO is creating quite a bit of interest. manual settings, m aking sure for example In N ew Zealand, W ellington R egional that sufficient w ater is transferred into a Council (WRC) has implem ented the rese rvoir befor e a pump station is scheduled off for mainten ance . The soft ware packa ge for online and real- time cost optim.isation in three water treatment graphical screen also provides inforplants and eleven customer reservoirs. The m ation on proj ected versus standard system controls w holesale wa ter distribution to most of the Lower Hutt and half of W ellington City. Its primary aim is to reduce wa ter and pumping costs th ro ugh predicti ve pump scheduling and efficient use of wa ter sources w ith different costs.

T he optimiser, called DER CETO , receives live demand and level data from a SCADA system and uses a combination of Mixed Integer Progranuning, hydraulic m odelling and heuristics to schedule production fo r a 24-hour period. D erceto takes into acco unt power tariffs, fixe d costs and produ ction costs, resource constraints, system constraints and varying demand. It then feeds the optimal schedules di rectly to the control system , starting and stopping pumps and scheduling production fro m treatment plants as required to minimise Phone or fax for sound technical advice energy costs w hile maintaining set operating from experienced personnel. criteria. It updates pump schedules eve1y half- ho ur, allowing it to cope with rapid changes in demand, fo r example due to to sudden weather changes .

T he use of a graphical easy-to-use fr o nt-end D erceto embedded in any QUALITY existing SCADA system , as shown in 319 Parramatta Road ENDORSED Figure 1, has made it simple fo r the COMPANY AUBURN NSW 2144 operators to view the pump schedules, and AS/ ISO 9002 Phone: (02) 9748 2309 allows m an ual adju stme nt of pump STANDARDS sc h edules to fac ilitate m ainten an ce AUSTRALIA Fax: (02) 9648 4887 requirem ents. Individual pumps or water Licence no: Email: trea tment plants can be scheduled o n and 1628 jamescumming@jamescumming.com.au off in half ho ur blocks up to 24 ho urs in adva nce. D erceto optimises aro und these

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WATER MARCH 2002

119

INNOVATION

instance, for the Waterloo WTP night tariffs vary throughout the year from 1 to 3 .Sc/ kWh and day tariffs from 2.7 to 5.Sc/ kWh .

Network charges are a monthly charge based on coincident maximum demand (CMD) and anytime maximum demand (AMD) . The CMD charge is the highest half- hour power consumption for the month between 8 and 10 a.m. and 5.30 and 7 p.m. on any weekday. The AMD charge is the highest half-ho ur power consumption for the month. The target is avoidance of CMD and minimisation of AMD charges.

Super solutions f0r: the water industry Join many of Austra lia's leading util ities already enjoyin g

Benefits At Waterloo WTP, night pumping has increased from approximately 23 percent to 40 percent. Other pumping stations have also show n increases in night pumping of approximately 10 percent co 50 percent.

N etwo rk charges comprise about 40% of the total electricity charges. C MD avoidan ce is more attainable in the winter demand months w hen there is more reservoir storage in relation to demand. The greatest opportunity for C MD savings is at Waterloo WTP w here approximately 80 percent savings have been ac hieved. C MD avoidance is largely dependent on operational requirements (such as system shutdowns, the availability of alternative gravity supply water every day to maintain pressure, pump failures, etc.) and demand.

Derceto also chooses the lowest marginal cost source of water, taking into account chemical, labour and energy costs.

These change during the day, especially for run-of-river plants, w hich can have rapid changes in water quality and h ence ch emical requirements. Derceto has rules to prevent rapid changes to flow set-points as this is detrimental to the production of good quality water. Even taking this into

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acco unt cost savings due to switching production to the lowest cost source of wa ter have been well worth-w hile.

Environmental Benefits The WRC is committed to sustainable environmental management and h as impl eme nt ed a n Environmental M anagem ent System (EMS). The EMS objective of " 4. 2.3: Reduce power use during coincident charge hours" with regard to the environmental policy " R ecognise and

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operate within the natural limits of natural resources, particularly water and conserve nonrenewable resources such as fuels, energy and materials" was achieved with the operation of the optimiser. (See www .derceto. com for further information).

The Authors John Wardle and Simon Bunn are w ith Beca Simons, ba se d in th e M elb ourne office, www.becasimons. com.au

Hatlar Environmental Pty Ltd Environmental Consultants The Hatlar Group of Companies provides Environmental & Project Management Services in the Following Key Areas: • • • • •

Cleaner Production & Waste Minimisation Trade Waste Management Chemical & Waste Management Environmental Site Assessments Treatment Plant Turnkey Operations

For Further Information: 120

WATER MARCH 2002

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enquiries@hatlar.com.au