Fitzgibbon Potable Roofwater
Harvesting (PotaRoo) Scheme
Final Report.
Prepared for the Department of Environment (DoE)
May 2014
Economic Development Queensland
Level 7, 63 George Street Brisbane
GPO Box 2202 Brisbane
Queensland 4001 Australia
Telephone +61 7 3452 7880
Website www.edq.qld.gov.au
ABN 76 590 288 697
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TABLE OF CONTENTS
PROJECT CLEARANCE .................................................................................................................................................. 3
EXECUTIVE SUMMARY .................................................................................................................................................. 4
1.
Introduction ................................................................................................................................................................ 5
2.
The Project ................................................................................................................................................................ 5
2.1 Fitzgibbon Chase ................................................................................................................................................ 5
2.2 Project Overview ................................................................................................................................................. 6
2.3 Roofwater Collection System .............................................................................................................................. 8
2.4 Roofwater Treatment Plant ................................................................................................................................. 8
2.5 Distribution........................................................................................................................................................... 9
2.6 Intended end uses of product .............................................................................................................................. 9
2.7 Objectives and Goals .......................................................................................................................................... 9
3.
Project Methodology ............................................................................................................................................... 10
4.
Project Governance ................................................................................................................................................ 11
4.1 Steering Committee ........................................................................................................................................... 11
4.2 Project Manager ................................................................................................................................................ 11
4.3 Project activities and conduct ............................................................................................................................ 11
5.
Project Activities ...................................................................................................................................................... 12
6.
Project Outcomes .................................................................................................................................................... 13
6.1 Supply Quality and Quantity .............................................................................................................................. 13
6.2 Supply Cost ....................................................................................................................................................... 15
6.3 Economic Outcomes ......................................................................................................................................... 15
6.4 Environmental Outcomes .................................................................................................................................. 16
6.5 OHS Outcomes ................................................................................................................................................. 16
6.6 Community / Social Outcomes .......................................................................................................................... 16
7.
Project Evaluation ................................................................................................................................................... 16
8.
Experience sharing and lessons learnt ................................................................................................................... 17
9.
Scheme Finance ..................................................................................................................................................... 17
10. Conclusions ............................................................................................................................................................. 17
PROJECT CLEARANCE
Function
Position
Name
Prepared by
Senior Development
Manager
Director – Residential
Development
Meg Macaulay
Approved by
Signature
Date
Peter Smith
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EXECUTIVE SUMMARY
The Fitzgibbon Potable Roofwater Harvesting (PotaRoo) scheme has been developed to demonstrate the potential for
harvested roofwater to be treated and used as a source of potable water supply at a local level.
Conceived in 2009 and constructed and commissioned over a three year period, the PotaRoo scheme will harvest
roofwater from approximately 500 houses in Fitzgibbon Chase and will, when fully operational, supply treated water
into the water supply grid for general consumption.
The PotaRoo scheme is yet to go into full operation, however, commissioning testing and ongoing analysis shows that
it will meet the project objectives, i.e. to provide an alternative source of water to reduce potable demand and improve
water supply security, and to not increase greenhouse gas emissions.
The scheme was successfully completed adopting a comprehensive design and assessment process, including water
balance modelling, risk assessment, business case development, baseline water quality monitoring, verification
testing and liaison with water supply and regulatory authorities.
The PotaRoo scheme will supply 44 ML/year of treated stormwater, 20 per cent of potable demand in Fitzgibbon
Chase, at a cost of approximately $2.60 per/kL.
The total cost of the PotaRoo scheme is estimated at $8,085,000 million dollars of which the Australian Government
contributed $4,050,000 million dollars. Nomura Research Institute (NRI), in conjunction with JFE Corporation (JFE)
provided $3,930,500 towards the scheme. Economic Development Queensland provided the balance of the budget at
$104,500.
The final report covers the entire project period and details the conduct, benefits and outcomes of the project as a
whole.
The PotaRoo scheme was developed in conjunction with the Fitzgibbon Stormwater Harvesting (FiSH) Scheme, which
has been developed to supply treated stormwater to residents within Fitzgibbon Chase for non-potable uses, ie toilet
flushing cold water laundry and gardens. Until the PotaRoo scheme is fully operational, treated water from that system
will feed into the FiSH scheme.
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1. Introduction
This report has been prepared as the Final Report to the Australian Government Department of Environment (DoE) as
required under the terms of the funding agreement for the Fitzgibbon Potable Roofwater Harvesting (PotaRoo)
scheme in Fitzgibbon, Brisbane Queensland.
The PotaRoo project received funding under the National Urban Water and Desalination Plan, Stormwater Harvesting
and Reuse Projects program and Japanese Government
Construction and commissioning of the PotaRoo scheme is complete, though it is yet to go into full service. This report
provides an overview of the project, the methodology and processes adopted in developing the scheme, and the key
outcomes from the project to date.
2. The Project
The aim of the Fitzgibbon Potable Roofwater Harvesting (PotaRoo) project is to produce potable water from
communally harvested roofwater. The scheme collects roofwater runoff from houses in the Fitzgibbon Chase
residential development to a central water treatment plant (WTP).
Once the process is proven and there is confidence to move forward, it is intended that the treated water will be
introduced into the water supply grid as a new bulk water supply.
2.1 Fitzgibbon Chase
Within the Fitzgibbon Chase two stormwater Harvesting and reuse schemes were developed.
The PotaRoo scheme was developed as part of the Minister for Economic Development Queensland’s (formally the
Urban Land Development Authority) Fitzgibbon Chase project. Fitzgibbon Chase is a residential subdivision located in
the northern suburbs of Brisbane approximately 12km north of the CBD (refer to Locality Plan Figure 1). The
development has a total area of approximately 114ha. Figure 2 shows the extent of the Fitzgibbon Chase
development.
Figure 1 Locality Plan
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Figure 2 Fitzgibbon Chase Development
2.2 Project Overview
The PotaRoo scheme consists of three main infrastructure sections:
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Collection system – captures roofwater from connected homes and transports it to one of four distributed
storages; captured water is pumped from the storages to the roofwater storage tank at the Water Treatment
Plans (WTP).
Treatment plant – treats captured water to potable standard.
Distribution system – pumps the treated water from the potable water tanks into the potable water distribution
main.
The PotaRoo scheme has been designed in accordance with the Australian Drinking Water Guidelines (NRMMC and
NHMRC 2011) and Queensland State Legislative requirements. Water supply systems in Queensland are subject to
regulation through the Office of the Water Supply Regulator (OWSR) under the provisions of the Water Supply Safety
and Reliability (WSS&R) Act 2008 and related parts of the Public Health Act and Regulations. Under the WSS&R Act
a Service Provider for a potable water supply scheme (i.e. supplying drinking water) is required to have in place an
approved Drinking Water Quality Management Plan (DWQMP) for the scheme.
The PotaRoo scheme is designed to operate alongside, but independently from, the Fitzgibbon Stormwater
Harvesting (FiSH) Project, a non-potable water harvesting and reuse scheme developed by Economic Development
Queensland (EDQ).
The general layout of the PotaRoo is shown in Figure 4. It is also shown schematically in Figure 3 below.
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Potable Water
Supply Network
Backwash
Micro
Filtration
AutoStrainer
Chlorine &
Fluoride
Ion
Exchange
Activated
Carbon
UV
Rainwater Storage Tank
800 kL
Raw Water
Tank 4 kL
Treated Water
Tank 4 kL
Potable Water Tank
100 kL
Drain
Sewer
Overflow
Excess to
Stormwater
Houses
Roof water Collection System
Distributed Underground
Storage Tanks
(4 Tanks, Total 900 kL)
Figure 3 PotaRoo Schematic Diagram
Figure 4 PotaRoo Layout
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2.3 Roofwater Collection System
The PotaRoo treats roofwater collected from the Fitzgibbon Chase development. The collection system consists of:
 House connections,
 Collection network,
 Distributed underground storage tanks (total volume 917 kL),
 Transfer pumps,
 Rising main, and a
 800kL above ground roofwater storage tank.
At each house connection the roofwater is diverted from the downpipes to the collection network. The house
connection also includes an overflow device which allows roofwater to overflow into the stormwater system when the
collection network is at capacity. Leaf boxes installed on the downpipe/gutter system reduce leaf matter entering the
system. Approximately 8ha of roof area will be connected to the collection system when the development is complete.
The collection network is a gravity pipe network that carries water from each of the house connections to the
distributed underground storage tanks. There are 4 separate catchment areas that drain to the distributed
underground storage tanks. The distributed underground storage tanks are Humes Rain Vaults® and range in size
from 100kL to 330kL. Each tank contains a pump well, transfer pump, level sensors and overflow. The transfer pumps
transfer roofwater from the distributed tanks to the roofwater storage tank, via the common rising main. The pumps
are controlled by a pressure switch, level switch and timer functions.
The 800kL roofwater storage tank is located adjacent to the treatment plant and an actuated valve on the inlet pipe
ensures that water with high turbidity cannot be transferred into the tank.
Figure 5 Collection System and Distributed Collection Tanks
2.4 Roofwater Treatment Plant
The key treatment processes adopted for the PotaRoo treatment train are as follows (refer to Figure 3):
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Auto-strainer (removal of coarse particulates),
NaOH dosing for pH correction,
Membrane treatment (microfiltration for removal of pathogens and fine particulates),
Activated carbon treatment (removal of organic contaminants),
Ion exchange treatment (removal of heavy metal contaminants, particularly zinc),
Ultraviolet disinfection (neutralisation of pathogens),
Residual chlorination using sodium hypochlorite, and
Fluoridation.
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Figure 6 Raw Water Tank, Water Treatment Plant and Treated Water Tank
Figure 7 Raw Water Tank and Water Treatment Plan
2.5 Distribution
In the short-term, until the PotaRoo Scheme has satisfied all requirements that it can consistently produce water of
potable quality, treated water will be used for non-potable purposes through the Fitzgibbon Stormwater Harvesting
(FiSH) scheme. Once the treated water is approved as potable standard, it will be injected into the Queensland Urban
Utilities (QUU) trunk water main on Telegraph Road, Fitzgibbon.
2.6 Intended end uses of product
The objective for the PotaRoo Scheme is to produce water meeting all of the requirements for drinking water and
suitable for injection into the water supply grid. Once this occurs, the water will be suitable, and used, for all normal
water uses, including drinking, cooking and washing.
In the short-term, the water will be used for non-potable water uses through the FiSH dual reticulation network, i.e.,
toilet flushing, cold water laundry, external household use (car washing and garden watering), and irrigation of public
open space.
2.7 Objectives and Goals
The over-riding objectives for stormwater harvesting schemes funded under the program are to contribute to:
a. Improving the security of water supplies in Australia, without adding to greenhouse emissions,
b. Reducing demand on potable water supplies, and
c. Helping to reduce the impact of urban runoff on water quality in receiving waters.
The specific objectives adopted for the PotaRoo were to:
a. Use harvested roofwater to offset potable water demands of approximately 44 ML/yr. within the Fitzgibbon
Chase Development Area.
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3. Project Methodology
The project was initiated in 2009 by the Japanese consultancy Nomura Research Institute (NRI), in conjunction with a
large Japanese industrial company JFE Corporation (JFE), as an opportunity to demonstrate and prove Japanese
technology overseas. NRI and JFE were pursuing Japanese government funding provided through its New Energy
and Industrial Technology Organisation (NEDO) aimed at supporting Japanese companies to develop overseas
markets for their products. Fitzgibbon Chase was identified as a suitable location and EDQ (formally Urban Land
Development Authority [ULDA]) was a willing participant. EDQ supported the project as consistent with a broader
objective to enhance the environmental sustainability of its developments.
The mechanisms and processes implemented for the PotaRoo can best be illustrated with a brief history of the project
development, highlighting the key milestones, decision points and activities:
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JFE signed a Memorandum of Understanding in November 2009 with the Queensland Government for
investigation and development of a roofwater harvesting system and a trial stormwater reuse system at a new
residential area within the Fitzgibbon Urban Development Area.
Initial feasibility investigations and a preliminary design were completed by Bligh Tanner Pty Ltd in November
and December 2009 respectively.
A funding application was submitted under the National Urban Water and Desalination Plan Stormwater
Harvesting and Reuse Projects Funding Scheme in February 2010 and funding was confirmed in September
2010.
Design and installation of the roofwater collection system in Fitzgibbon Chase commenced with stage 6 in
July 2011.
Detailed design of the water treatment plant and associated systems was completed by JFE and Bligh Tanner
in November 2009 with expressions of influence called in July 2010.
Detailed design of the distributed storage tanks was completed by Bligh Tanner in December 2011 with
tenders also called in December 2011. The contract was awarded to Pensar Civil Pty Ltd in February 2012.
A detailed Water Quality Risk Management Plan (WQRMP) was developed in conjunction with all key
stakeholders (ULDA, QUU, Queensland Health and the Office of the Water Supply Regulator) to inform the
design process and ensure that all risks had been identified and addressed; this was completed in November
2011.
A Business Case was also developed in November 2011 to consider the cost of operating the system and the
likely cost of water from the system.
In November 2010, a contract was awarded to Pensar Building Pty Ltd, in conjunction with Amiad Filtration
Systems Ltd for water treatment works, to build the PotaRoo treatment plant. Construction of the civil works
reached Practical Completion in September 2011.
Construction and initial commissioning of the water treatment plant was completed in 2013.
In September 2012, JFE undertook the first round of ‘Challenge Tests’ to confirm the plant capacity to remove
pathogens (bacteria, viruses and protozoa); a second round of ‘Challenge Tests’ assessing the removal of
organic chemical pesticides and metals was completed in October 2012.
Between November 2012 and November 2013, JFE temporarily mothballed the water treatment plant to
provide time for the connection of adequate roof area to ensure that water would be available to allow
verification testing to proceed.
In March 2013 development responsibility for Fitzgibbon Chase transferred to Economic Development
Queensland (EDQ), part of the Department of State Development, Infrastructure and Planning (DSDIP).
Since the early stages of the design, EDQ and Bligh Tanner have maintained continual liaison and coordination with the local water utility QUU with respect to the impact of the system on its services and the
potential for QUU to be the ultimate owner and operator of the scheme.
Between November 2013 and January 2014, JFE undertook extensive verification testing to obtain baseline
data on the untreated roofwater in the system and to demonstrate that the plant could reliably produce potable
water.
In April 2014, a draft Drinking Water Quality Management Plan (DWQMP), following the Queensland State
guidelines for preparation of a DWQMP, was completed. This was prepared to ensure that the risk and
requirements for on-going plant operation were well understood and documented and to support the future
scheme operator.
The plant is now fully commissioned and ready to go into service, subject to identifying a suitable operator.
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4. Project Governance
To effectively manage the design and delivery of the PotaRoo scheme the following governance arrangements were
made. These are standard for large projects delivered by the Economic Development Queensland.
4.1 Steering Committee
A steering committee has been created including members at director and management level. The role of the steering
committee was to:
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Provide advice and guidance to Economic Development Queensland’s contractual commitments to its key
funders
Monitor relationships with key stakeholders
Review and approve whole-of-project budget and cash flow
Review and approve the whole-of-project schedule and achievement of milestones
Review and authorise project risks and the project risk assessment.
Steering committee members included the following people periodically over the life of the scheme:
Mr Peter Smith – EDQ
Ms Meg Macaulay – EDQ
Mr Peter Kelly - EDQ
Mr Chris Tanner – Bligh Tanner
Mr Damien Stiler – Bligh Tanner
Mr Yasuto Ando – JFE Engineering
Mr Atsunori Sato – JFE Engineering
Mr Inakoshi Osamu – JFE Engineering
Director – Residential Development
Senior Development Manager
Project Manager
Civil Engineer
Civil Engineer
Commercial Manager
Commercial Manager
Commercial Manager
4.2 Project Manager
The project manager is accountable for the successful delivery of the scheme to meet the time, quality and cost
parameters agreed with key stakeholders including the Department of the Environment. The role encompasses:
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Provide management of the scheme
Prepare Milestone and Status Reports prior to submission to the steering committee
Day-to-day management of budgetary expenditure and schedule
Day-to-day management of designers and contractors
Manage project risks and project risk assessment
Undertake tender process for design activities and construction works
Co-ordinate internal stakeholder engagement
Co-ordinate the works with other activities occurring within the development site
Provide representation to external stakeholders and co-ordination with those stakeholders to achieve required
project outcomes.
4.3 Project activities and conduct
The design and construction project management was conducted in-house by the residential development division of
EDQ. The design for each project was developed through the lead consultant (Bligh Tanner) to tender documentation.
The tender process conformed to Queensland Government standards for public tenders. The successful tenders
where engaged directly to EDQ with supervision of the contracts through external consultants (Blight Tanner, ETS
Engineering and Brown Consulting Group). External expertise was engaged as necessary to ensure the design intent
and building standards were complied with.
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5. Project Activities
Activities Completed to Date
MILESTONE DESCRIPTIONS
Fund Agreement executed .
INITIAL PROJECT PLANNING
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MILESTONE
COMPLETION DATE
12 May 2011
July 2011
Complete project planning, and amend projections as required.
AREA E: STAGE 6
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Complete Collection System design and commence construction.
A.1.2.
WATER TREATMENT PLANT
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Commence Water Treatment Plant work design, tendering and
award of contract.
Complete Water Treatment Plant civil and building works.
DESIGN VALIDATION
 Commence design validation.
AREA E: STAGES 7 AND 8
November 2011
 Complete collection system design for Stages 7 and 8.
 Commence construction to Stage 7.
WATER TREATMENT PLANT
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Complete Water Treatment Plant.
Undertake testing and commission Water Treatment
Plant.
DESIGN VALIDATION
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Continue design validation.
AREA C
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Commence Collection System design.
May 2012
AREA E: STAGES 7 AND 8
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Complete construction to Stage 7.
Commence construction to Stage 8.
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AREA C:
 Complete collection system design.
AREA C
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Commence construction.
November 2012
March 2013
AREA E: STAGE 8
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Complete construction.
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Complete Collection System construction.
Complete commissioning of Collection System (for Area C).
AREA C:
March 2014
AREA E: STAGE 6
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Complete construction.
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Complete commissioning of Collection Systems for Stages 6, 7
and 8.
WATER TREATMENT PLANT
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Commissioning of Water Treatment Plant.
DESIGN VALIDATION
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Complete design validation.
Activities to be completed
MILESTONE DESCRIPTIONS
Final Drinking Water Quality Management Plan (DWQMP)
Tenders called for operation and maintenance of the PotaRoo
ESTIMATED
MILESTONE
COMPLETION DATE
June 2014
June 2014
Confirmation of plant operator and handover
September 2014
PotaRoo goes into operation supplying water into the FiSH
December 2014
PotaRoo commences supply of drinking water into the water supply grid
December 2016
6. Project Outcomes
6.1 Supply Quality and Quantity
As noted above, the PotaRoo is yet to supply water into the water supply grid. However, during commissioning testing,
it successfully demonstrated that water can be harvested and delivered at a water quality meeting all of the
requirements for potable use.
A review of system yield completed in 2013 has confirmed that the system performance will be as follows:
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Total treated roofwater supplied into water supply grid – 44 ML/yr. (average)
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During initial start-up and commissioning it has been demonstrated that the water is successfully collected into the
distributed storages and transferred to the main rainwater storage tank. The verification testing program completed in
2014 has demonstrated that the water treatment plant is effective at treating to the specified quality and at the
required rate of 200kL/day. Over the 3 month verification testing period, the plant treated 2.0 ML of water and
consistently met the design water quality requirements.
The verification testing was supported by the challenge testing undertaken in 2012 demonstrating that the plant as
installed can achieve the contaminant log reductions required under Australian guidelines.
Challenge Test 1 assessed the ability of the treatment train to remove bacteria, viruses and protozoa. High
concentrations of laboratory generated test contaminants were inoculated into the process and water test taken
upstream, downstream and within the plant to test individual unit process removal. The challenge testing
demonstrated that the plant achieves log reductions in excess of guideline performance values and meets minimum
treatment requirements.
Challenge Test 2 assessed the removal of organic pesticides and metals. The WTP successfully removed all
inorganics (metals) below ADWG guideline levels and successfully removed all test organics, with the exception of
Glyphosate. Further testing of Glyphosate was recommended to check the influence on the results of the very high
feed concentrations.
The verification testing program was undertaken by JFE over a 3 month period, with sampling occurring in 3 sets of 3
days at 1 month intervals. JFE adopted a comprehensive test regime; sampling upstream, downstream and through
the treatment train to assess feed water quality, treated water quality and individual unit process performance over a
comprehensive range of test parameters. The treated water quality test results are summarised below.
The system is now fully commissioned and ready to be placed into service.
Table 1 Water Treatment Plant Verification Test Results
Test Parameters
Microbiological
Coliforms
Faecal Coliforms
Escherichia Coli
Enterococci
Parasites (Giardia &
Cryptosporidium)
Viruses (Adenovirus & Rotavirus)
Others (Salmonella, Legionella,
Aeromonas, Clositridium
perfringens, f-RNA coliphage,
Somatic coliphage, Shigella,
Campylobacter
Physical
Units
CFU/100 mL
CFU/100 mL
CFU/100 mL
CFU/100 mL
cysts/10L
oocysts/10L
-
No. of
Samples
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Guideline
Value
Results
Mean
95%ile
<13
62
<1
<1
<1
Not detected
3
<1.0
2
Not detected
3
Not detected
Colour (true)
PCU
9
Hardness (as CaCO3)
mg/L
9
Total Dissolved Solids @180°C
mg/L
9
Aluminium (acid soluble)
mg/L
9
Copper
Lead
Zinc
Iron
mg/L
mg/L
mg/L
mg/L
9
9
9
9
15 HU
(Aesthetic)
200
(Aesthetic)
600
(Aesthetic)
6
9
96
196
303
472
<0.012
0.026
Metals
0.2
(Aesthetic)
2
0.01
3 (Aesthetic)
0.3
<0.001
0.001
<0.001
<0.006
0.011
<0.05
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Units
No. of
Samples
Guideline
Value
mg/L
3
varies
Ammonia
mg/L
9
Nitrate
Nitrite
Inorganics
mg/L
mg/L
9
9
Chloride
mg/L
9
Fluoride
mg/L
9
Sulfide
mg/L
9
Reactive Silica
mg/L
9
Sodium
mg/L
9
Sulfate
mg/L
9
250
(Aesthetic)
1.5
0.05
(Aesthetic)
80 (Aesthetic)
180
(Aesthetic)
500
Others
mg/L
3
varies
Test Parameters
Others
Results
Mean
95%ile
Significantly below
guideline value
Nutrients
0.5
(Aesthetic)
50
3
0.03
0.05
0.28
0.36
<0.01
92
153
<0.1
0.1
<0.01
6.08
10.42
71
99
44
78
Significantly below
guideline value
Organics
Organics
Hydrocarbons
Hydrocarbons
Disinfection By-products
Chlorate
Formaldehyde
N-Nitrosodimethylamine (NDMA)
Trihalomethanes (thMs) (total)
mg/L
mg/L
mg/L
mg/L
3
3
3
1
Others
Algal Toxins
Microcystin LR
Pesticides
Pesticides
varies
Significantly below
guideline value
varies
not detected
0.5
0.0001
0.25
varies
mg/L
<0.005
<0.1
<0.000003
<0.016
<0.029
Significantly below
guideline value
2
1.3
<0.0003
9 (total) Inc.
3 (full suite)
varies
not detected
6.2 Supply Cost
A review of the system yield and operating costs completed in 2014 based on analyses completed and agreed for the
PotaRoo scheme has confirmed that the system performance will be as follows:
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Operating cost of water - $2.60per/kL.
Operating costs include labour, electricity, consumables, on-going verification testing, event management /
monitoring and source management.
6.3 Economic Outcomes
The economic benefits from this and similar schemes arise from the reduction in potable water required and the
demonstrated potential for decentralised schemes to reduce the need for major new water supply capacity.
The direct benefit to the potable water supply system is 44 ML/year of water, valued at $155,000 that will not need to
be supplied. A water supply equivalent to 20per cent of the Fitzgibbon Chase water demand illustrates the potential for
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decentralised water harvesting schemes (or Local Alternative Water Supplies) to make a significant contribution to
regional water supply capacity and significantly reduce and defer requirements for future major water supply
augmentation. This is significant because future increases in regional water supply capacity are likely to be from costly
seawater desalination, as there are only limited opportunities remaining for new surface water storages.
6.4 Environmental Outcomes
The primary environmental outcome from roofwater harvesting is the indirect benefit to the stormwater drainage
system of removing a proportion of total runoff, with its associated contaminants, from the drainage system, thereby
reducing the sediment and nutrient export load and the need for water quality improvement devices. Based on an
evaluation by Bligh Tanner in 2012, the combined benefits of the FiSH and PotaRoo schemes, when compared with
pollutant reduction targets required under the State Planning Policy 4/10 Healthy Waters, was in excess of 50% of the
Suspended Solids removal required and 75% and 90% of the Phosphorus and Nitrogen removal targets respectively.
An assessment of energy consumption by the PotaRoo Scheme suggests that it will use perhaps 15 per cent more
energy per ML of water supplied than the South East Queensland regional water supply system (2,500 cf 2,200 1
MJ/ML) based on the current sources of supply. Future new sources are expected to have significantly higher energy
requirements due to treatment technologies (eg RO) and the distance water has to be pumped to urban centres.
The PotaRoo Scheme will be powered by green energy from the grid to further limit its contribution to greenhouse
emissions.
6.5 OHS Outcomes
Raw water testing has shown that the untreated roofwater is relatively free form contamination. The verification testing
program has confirmed that the plant can produce water meeting all potable water quality requirements. With the
safeguards and water treatment systems provided, the PotaRoo scheme will meet the minimum requirements for
human consumption, ensuring that the community users of the water, and the system operators, are protected from
the risk of waterborne disease or other adverse health effects.
6.6 Community / Social Outcomes
By making available and maintaining their roof drainage systems, householders are contributing to the realisation of
the greater community benefit of roofwater harvesting for water supply. As the treated water will be injected into the
drinking water supply, consumers, whether in Fitzgibbon Chase or outside, will not be aware that they are using
treated roofwater and will not be affected by it.
7. Project Evaluation
While the scheme is yet to supply water to consumers there is confidence that, based on the system that has been
developed, and the analyses undertaken, the schemes objectives will be met:
1. The PotaRoo scheme will produce an alternative supply of water for potable uses that will offset 44ML/year of
potable water demand; this represents approximately 20 per cent of total water demand in Fitzgibbon Chase.
2. By providing that offset, the PotaRoo scheme demonstrates that local alternative water supplies have the
potential to improve the security of regional water supplies in Australia and to reduce and defer the need for
major new source augmentations.
3. As a local system, the PotaRoo is a relatively low energy user compared with alternative sources requiring
pumping over long distances; in addition, power for the scheme will be sourced from green power ensuring
that the overall impact on greenhouse emissions is minimised.
4. By removing 44ML/yr of stormwater runoff, the PotaRoo will significantly reduce pollutant loads from the
catchment and improve the quality of stormwater entering local waterways.
Fitzgibbon Chase is a developing residential estate and is subject to market forces. This may necessitate a slow down or
acceleration of construction. Stages may also be changed or swapped to maintain margins. This may affect the overall program
however at this time completion of the estate is on program.
1
Energy use in the provision and consumption of urban water in Australia: an update, Prepared by CSIRO for the Water Services Association of
Australia, May 2012.
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8. Experience sharing and lessons learnt
The following key learnings have been noted for future projects:
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There are restrictive and expensive requirements for scheme validation, ongoing verification and auditing
presents financial risk to the development of new schemes;
There are no clear models for governance of alternative waters sources, including ownership and operation,
and how they are integrated into the municipal water system generally; this is perhaps the greatest current
challenge to their widespread implementation;
Fitzgibbon Chase is a developing residential estate and is subject to market forces. This may necessitate a
slow down or acceleration of construction. Stages may also be changed or swapped to maintain margins. This
may affect the overall scheme program and agreed funding milestones;
An independent assessment of the proposed design of the scheme can be valuable in cross checking suitable
design, scheme budgets and viability; and
Consistent project management and design/supervision roles is invaluable to ensuring the delivery of the
original objectives.
Benefit of undertaking complementary projects concurrently (FiSH and PotaRoo Schemes) assist with
knowledge sharing and positive project outcomes.
9. Scheme Finance
The original scheme budget was set at $8,100,000. The current budget is set at $8,084,842. This is approximately
$15,158 less than the cost estimate used for the funding submission. The small budget saving can be primarily
attributed to design revisions as the scheme moved from concept to detailed design.
The Australian Government provided $4,050,000 towards the PotaRoo scheme. Nomura Research Institute (NRI), in
conjunction with JFE Corporation (JFE) provided $3,930,464 towards the scheme. Economic Development
Queensland provided the balance of the budget at $104,378.
A detailed cost summary is provided in the Financial Report.
10. Conclusions
Development of the PotaRoo scheme has confirmed that roofwater harvesting for potable supply is technically
feasible, cost effective and could form an important part of the regional water supply strategy, though challenges
remain to confirm its acceptance as a viable source by the water community and to determine the best business
model for delivery:
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The technology required is readily available and well understood.
Adequate guidelines exist to assist with design, though there is a lack of consistency across jurisdictions and
water sources.
Restrictive and expensive requirements for scheme validation, ongoing verification and auditing present a
financial risk to the development of new schemes.
There are no clear models for governance of alternative waters sources, including ownership and operation,
and how they are integrated into the municipal water system generally; this is perhaps the greatest current
challenge to their widespread implementation.
The community has benefitted twice-fold from this project – the use of treated rain water from rooves is
reused into the water supply and the excess water is then fed into Carseldine Drain where it is harvested as
stormwater, treated and used for non potable water supply within the Fitzgibbon Chase Development.
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