...

COOK et al 2009 Definition of Decentralised Systems in the South East Queensland Context

by user

on
Category: Documents
2

views

Report

Comments

Transcript

COOK et al 2009 Definition of Decentralised Systems in the South East Queensland Context
Definition of Decentralised Systems in
the South East Queensland Context
Stephen Cook, Grace Tjandraatmadja, Angel Ho and
Ashok Sharma
May 2009
Urban Water Security Research Alliance
Technical Report No. 12
Urban Water Security Research Alliance Technical Report ISSN 1836-5566 (Online)
Urban Water Security Research Alliance Technical Report ISSN 1836-5558 (Print)
The Urban Water Security Research Alliance (UWSRA) is a $50 million partnership over five years between the
Queensland Government, CSIRO’s Water for a Healthy Country Flagship, Griffith University and The
University of Queensland. The Alliance has been formed to address South-East Queensland's emerging urban
water issues with a focus on water security and recycling. The program will bring new research capacity to
South-East Queensland tailored to tackling existing and anticipated future issues to inform the implementation of
the Water Strategy.
For more information about the:
UWSRA - visit http://www.urbanwateralliance.org.au/
Queensland Government - visit http://www.qld.gov.au/
Water for a Healthy Country Flagship - visit www.csiro.au/org/HealthyCountry.html
The University of Queensland - visit http://www.uq.edu.au/
Griffith University - visit http://www.griffith.edu.au/
Enquiries should be addressed to:
The Urban Water Security Research Alliance
PO Box 15087
CITY EAST QLD 4002
Ph: 07-3247 3005; Fax: 07-3405 3556
Email: [email protected]
Citation: Stephen Cook, Grace Tjandraatmadja, Angel Ho and Ashok Sharma (2009). Definition of
Decentralised Systems in the South East Queensland Context. Urban Water Security Research Alliance
Technical Report No. 12.
Copyright
© 2009 CSIRO To the extent permitted by law, all rights are reserved and no part of this publication covered by
copyright may be reproduced or copied in any form or by any means except with the written permission of
CSIRO.
Disclaimer:
The partners in the UWSRA advise that the information contained in this publication comprises general
statements based on scientific research and does not warrant or represent the accuracy, currency and
completeness of any information or material in this publication. The reader is advised and needs to be aware that
such information may be incomplete or unable to be used in any specific situation. No action shall be made in
reliance on that information without seeking prior expert professional, scientific and technical advice. To the
extent permitted by law, UWSRA (including its Partner’s employees and consultants) excludes all liability to
any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other
compensation, arising directly or indirectly from using this publication (in part or in whole) and any information
or material contained in it.
Cover Photograph:
Location: Mawson Lakes, South Australia (2008).
Photographer: Stephen Cook, Research Scientist CSIRO Highett
© 2008 CSIRO
ACKNOWLEDGEMENTS
CSIRO Land and Water would like to acknowledge the following for their assistance and advice
provided in developing this report:
Project Reference Group
Bill Clarke – University of Queensland
Brian Davis – Qld Department of Natural Resource and Water
Cynthia Mitchell – University of Technology Sydney
David Hamlyn-Harris – Bligh Tanner Pty Ltd
Francis Pamminger – Yarra Valley Water
Jan Warnken – Griffith University
Ted Gardner – Qld Department of Natural Resource and Water
Alliance Management
Don Begbie
Alan Gregory
All the individuals and organisations that have generously given their time to provide information and
discuss their experiences with decentralised systems, particularly members of the following
organisations:
Bligh Tanner Pty Ltd, Brisbane City Council, Central Queensland University, Department of
EPA (QLD), Department of Infrastructure and Planning (QLD), Department of Queensland
Health, Department of Natural Resources and Water (QLD), Econova Pty Ltd, GHD Pty Ltd,
Gold Coast Water, Maunsell Australia Pty Ltd, Toowoomba City Council, Worley Parsons Ltd,
WBM Pty Ltd.
Definition of Decentralised Systems in the South East Queensland Context
Page i
FOREWORD
Water is fundamental to our quality of life, to economic growth and to the environment. With its
booming economy and growing population, Australia's South-East Queensland (SEQ) region faces
increasing pressure on its water resources. These pressures are compounded by the impact of climate
variability and accelerating climate change.
The Urban Water Security Research Alliance, through targeted, multidisciplinary research initiatives,
has been formed to address the region’s emerging urban water issues.
As the largest regionally focused urban water research program in Australia, the Alliance is focused on
water security and recycling, but will align research where appropriate with other water research
programs such as those of other SEQ water agencies, CSIRO’s Water for a Healthy Country National
Research Flagship, Water Quality Research Australia, eWater CRC and the Water Services
Association of Australia (WSAA).
The Alliance is a partnership between the Queensland Government, CSIRO’s Water for a Healthy
Country National Research Flagship, The University of Queensland and Griffith University. It brings
new research capacity to SEQ, tailored to tackling existing and anticipated future risks, assumptions
and uncertainties facing water supply strategy. It is a $50 million partnership over five years.
Alliance research is examining fundamental issues necessary to deliver the region's water needs,
including:




ensuring the reliability and safety of recycled water systems.
advising on infrastructure and technology for the recycling of wastewater and stormwater.
building scientific knowledge into the management of health and safety risks in the water supply
system.
increasing community confidence in the future of water supply.
This report is part of a series summarising the output from the Urban Water Security Research
Alliance.
All reports and additional information about the Alliance can be found at
http://www.urbanwateralliance.org.au/about.html.
Chris Davis
Chair, Urban Water Security Research Alliance
Definition of Decentralised Systems in the South East Queensland Context
Page ii
CONTENTS
Acknowledgements .................................................................................................................i
Foreword .................................................................................................................................ii
Executive Summary................................................................................................................1
1.
Introduction ...................................................................................................................2
2.
Decentralised Systems .................................................................................................3
2.1.
2.2.
Definitions and Applications of Decentralised Wastewater Systems ..................................4
Features of Decentralised Systems.....................................................................................5
2.2.1.
2.2.2.
2.2.3.
2.2.4.
2.2.5.
2.3.
Rainwater Tanks............................................................................................................... 5
Stormwater Systems ........................................................................................................ 6
Greywater Recycling Systems.......................................................................................... 6
Wastewater Recycling Systems ....................................................................................... 6
Demand Management Strategies ..................................................................................... 6
Consultation with Water Professionals in SEQ..................................................................10
2.3.1.
Consultation Results: Aspects of Decentralised Systems ............................................. 11
3.
Scale of Decentralised Systems ................................................................................13
4.
Definition of Decentralised Systems .........................................................................15
5.
Conclusion...................................................................................................................15
References ............................................................................................................................16
LIST OF FIGURES
Figure 1:
Figure 2:
Figure 3:
Figure 4:
Centralised approach versus decentralised approach....................................................................... 3
On-site wastewater system (Source: Sharma et al, 2005)............................................................... 13
Cluster scale reclaimed water reuse system (Source: Sharma et al, 2005) .................................... 14
Development scale decentralised systems...................................................................................... 14
LIST OF TABLES
Table 1:
Table 2:
Queensland developments adopting the integrated urban water cycle management
approach (Tjandraatmadja et al. 2008; <http://www.naiad.net.au>) .................................................. 7
Developments adopting integrated urban water cycle management approach in states other
than Queensland (Tjandraatmadja et al. 2008; www.naiad.net.au)................................................... 8
Definition of Decentralised Systems in the South East Queensland Context
Page iii
EXECUTIVE SUMMARY
Decentralised systems based on integrated urban water management (IUWM) and water sensitive
urban design (WSUD) principles are being planned and implemented for urban developments, either
as separate facilities or in combination with a centralised system. Adoption of decentralised systems in
South East Queensland is primarily being driven by the pressure exerted on existing water resources
and the environment from rapid urban growth and an extended period of below average rainfall.
Water professionals apply the terminology ‘on-site and decentralised systems’ in many ways, thus
there exists some degree of confusion. Aiming to clarify understanding on terminology, this report
explores the definition of decentralised systems, outlines the key aspects of a decentralised approach
to water and wastewater services and investigates the scale of these systems in the specific context of
South East Queensland (SEQ).
The definition was developed using a literature review and consultation with water professionals from
state government departments, water authorities and consultants in SEQ using informal interviews
and/or a questionnaire.
This report discusses identifying characteristics of decentralised systems in terms of technological
options, features and scale. These characteristics were identified through analysis of cases studies in
both SEQ and other regions of Australia.
In summary, the definition of decentralised systems is determined mainly by the process adopted for
their design and implementation. Their characteristics range in technological features, system
configuration and development size from a single lot to 8,500 lots or even higher, but most
importantly are governed by the conditions of the development to which they are applied.
The general definition of decentralised systems recommended for adoption as follows:
Decentralised systems can be defined as systems provided for water, wastewater and
stormwater services at the allotment, cluster and development scale that utilise alternative
water resources, including rainwater, wastewater and stormwater, based on a ‘fit for purpose’
concept. These systems can be managed as stand-alone systems, or integrated with centralised
systems. Wastewater streams are partially or completely utilized at or close to the point of
generation. At cluster and development scale, stormwater is also managed as part of an
integrated approach that aims to control the quality and quantity of runoff at or near the
source to minimise the impact of the development on the natural ecosystem.
Definition of Decentralised Systems in the South East Queensland Context
Page 1
1.
INTRODUCTION
Decentralised systems involve the collection, treatment and use of rainwater, stormwater, groundwater
or wastewater at different spatial scales, from individual homes, clusters of homes, urban
communities, industries, or built facilities, as well as from portions of existing communities either
independent from or as part of a larger system (adapted from Crites and Tchobanoglous, 1998).
In comparison, conventional municipal water supply systems are characterised by the acquisition of
fresh water from protected catchments, purification of raw water and safe distribution in sufficient
quantities. Similarly, conventional wastewater systems can be stereotyped by the collection of sewage
via piped collection systems; transportation out of the urban area; and controlled discharge of treated
wastewater into receiving water bodies, including management of waste sludge (Wilderer, 2001). Such
approaches are commonly defined as centralised water and wastewater management systems.
In such systems, only a small fraction of high quality water supplied is used for drinking and cooking.
A large amount of water is used for toilet flushing and transporting the human waste through sewers to
treatment plants. The discrete collection of freshwater and disposal of wastewater may adversely
impact the water balance of that area. Infiltration into sewers can cause overloading of treatment plants
and exfiltration can contaminate groundwater and surrounding waterways. Centralised systems have
provided considerable benefits to modern society, particularly for the safe and reliable supply of water,
improved public health through removal and treatment of wastewater, and flood mitigation. However,
centralised collection and treatment of wastewater restrict opportunities to harness this potentially
valuable resource that can be used on a fit-for-purpose basis for a range of non-potable applications.
Furthermore, rapid urbanisation, increased pressure on water resources and the need to minimise
contaminant loads to receiving waters has meant that conventional centralised systems are not always
the most appropriate solution for urban development.
Historically, decentralised systems have been provided in semi-urban, rural and remote areas, where
the provision of centralised systems is not technically, economically or environmentally feasible.
Decentralised systems also offer an alternative approach to providing water, wastewater and
stormwater services to urban areas. The concept of integrating water and wastewater systems through
separate collection and treatment of various water and waste streams and recovery of valuable water,
nutrients and energy has been proposed (Wilderer, 2001). This helps to overcome the limitations of the
centralised approach and to move towards more ecologically and economically sound
water/wastewater management systems. Furthermore, innovative decentralised systems are being
planned and implemented for new and future urban developments, either as separate facilities or in
combination with a centralised system (Diaper, Sharma and Tjandraatmadja, 2008).
Mitchell and White (2003) provided some of the guiding strategies to be applied to urban water
systems in order to move towards sustainability. Strategies included: recognising limits to water that
can be extracted from a catchment; ensuring most efficient water use; ensuring adequate flows to local
ecosystems; and maximising efficiency in the use of energy and materials to deliver a service. These
guiding strategies provide a rationale to move towards decentralised systems, which in some cases
may be integrated with a centralised system. Decentralised wastewater systems can also offer the
significant advantage of enabling opportunities for localised water reuse (Gikas and Tchobanoglous,
2009).
There is a degree of confusion among many water professionals in the application of terminology
related to on-site and decentralised systems. This report defines the key aspects of a decentralised
approach to water and wastewater services in order to facilitate a clear definition of decentralised
systems. The methodology used to define decentralised systems was determined by a literature review
and through consultation with water professionals from state government departments, water
authorities and consultants in SEQ using informal interviews and/or a questionnaire.
The objectives of this report are to define decentralised systems and investigate the scale of these
systems in specific context to South East Queensland (SEQ).
Definition of Decentralised Systems in the South East Queensland Context
Page 2
2.
DECENTRALISED SYSTEMS
Decentralised systems are generally understood as being localised wastewater systems or as systems
supplying water resources that are sourced close to the point of use.
Decentralised water supply systems, such as rainwater tanks and groundwater extraction, are prevalent
in servicing remote or small dispersed communities (UNESCO, 2008).
Historically, the literature uses the term ‘decentralised systems’ to refer to on-site, clustered or
development scale decentralised wastewater systems. Figure 1 illustrates the concept of a
decentralised wastewater system in comparison to a conventional centralised system. A decentralised
approach that provides water and wastewater services can involve an amalgam of systems at the onsite (or allotment) scale and those at the cluster or development scale. The following describes the
different scales that decentralised systems can operate at:

Onsite scale. Treatment technologies and/or management systems that provide water and
wastewater services at the scale of an individual lot (Mitchell et al. 2008). Approaches include
rainwater tanks and greywater recycling. These systems are owned by allotment holders.

Cluster or development scale. These systems generally operate under some form of common
ownership model and service two or more dwellings or a whole development, with water
sourced or wastewater treated in proximity to the dwellings (Geisinger and Chartier, 2005).
Approaches include wastewater recycling with third pipe distribution and stormwater
harvesting.

Distributed systems. These systems generally provide services to very large developments and
the services are owned and operated by water utilities.
Decentralised systems may or may not be integrated with a centralised system. Danielson (2008)
referred to distributed wastewater management to describe systems where the management of several
systems is undertaken by a single entity. In many cases where decentralised systems are deployed,
they are integrated with the centralised system. For example, the Payne Road development in
Brisbane’s suburban fringe demonstrates an integrated approach to water services that includes
rainwater harvesting, greywater recycling and demand management. The decentralised systems are
integrated with the centralised system as rainwater tanks receive back-up from the mains supply and
blackwater is discharged off-peak to an adjacent sewer main.
Gikas and Tschobanoglous (2009) introduced the term ‘satellite wastewater systems’. These systems
are usually located in the upper portion of a wastewater system and usually lack solids processing
facilities. These satellite systems can reduce demands on centralised infrastructure, while enabling
opportunities for localised wastewater recycling and reuse.
Figure 1:
Centralised approach versus decentralised approach
Source: Adapted from Geisinger and Chartier (2005).
Definition of Decentralised Systems in the South East Queensland Context
Page 3
2.1.
Definitions and Applications of Decentralised Wastewater
Systems
In this section, definitions of decentralised wastewater systems taken from the literature are
highlighted. Typical features of decentralised systems are then described, followed by a summary of
feedback from a range of water professionals on defining decentralised systems.
Decentralised wastewater systems are well defined in associated government standards and in its code
and guidelines which were developed to provide guidance on wastewater system design, installation
and operations to ensure long-term treatment effectiveness and environmental protection.
Australian/New Zealand Standards 1547:2000 (On-site domestic wastewater management) defines an
on-site domestic wastewater water system as:
A system receives treats and absorbs wastewater within the property boundaries of the site of
generation.
The application of the Standard is limited to wastewater flows up to a maximum of 14 kL per week
from a population equivalent (EP) up to ten persons.
The Queensland Plumbing and Wastewater Code (2007) covering up to 20 EP defines an on-site
wastewater management system as:
A system installed on premises that receives and treats wastewater generated on the premises
and applies the resulting effluent to an approved disposal or re-use system.
This code covers on-site wastewater systems capable of treating not more than 50 kL per day of
wastewater generated on the premises.
The Interim Final Queensland Guidelines for Decentralised Wastewater Systems (2007) (unpublished)
define decentralised wastewater system as:
A wastewater system serving any small to medium-scale development that is an
Environmentally Relevant Activity (ERA) under the Queensland Environmental Protection
Regulations (1998) and which operates independently of a centralised municipal wastewater
collection and treatment system.
These guidelines were developed for systems with capacity from 21 to 1,000 EP in order to be
consistent with the systems defined as an Environmentally Relevant Activity (ERA) under the
Environmental Protection Regulation and required Development Approval from the Environment
Protection Agency (EPA).
Outside of Australia, Geisinger and Chartier (2005) define decentralised wastewater systems in the US
context as:
Decentralised systems: An onsite or cluster wastewater system that is used to treat and dispose
of relatively small volumes of wastewater, generally from individual or groups of dwellings and
businesses that are located relatively close together. Onsite and cluster systems are commonly
used in combination.
The US EPA (2005) document, ‘Decentralised treatment wastewater systems - A Program Strategy’,
defines decentralised wastewater systems as:
Decentralised wastewater systems, often called “septic” or “onsite” systems, derive their name
from their location—they treat wastewater close to the source, typically providing treatment on
the property of individual homes or businesses. Decentralised systems also include systems
serving clusters of individual homes, large capacity septic systems, and small collection and
treatment systems (including package treatment plants). These systems similarly treat
wastewater close to the source, typically using small pipes for collecting small volumes of
domestic wastewater, unlike centralised urban wastewater treatment systems that pipe large
amounts of wastewater many miles through sewers prior to reaching the treatment facility.
A similar definition is used by George Tchobanoglous for ‘decentralised wastewater management’,
which even includes ‘reuse’:
Definition of Decentralised Systems in the South East Queensland Context
Page 4
Decentralised wastewater management may be defined as the collection, treatment, and
disposal/reuse of wastewater from individual homes, clusters of homes, isolated communities,
industries, or institutional facilities, as well as from portions of existing communities at or near
the point of generation (Tchobanoglous, 1995 and Tchobanoglous, 1996 in Crites and
Tchobanoglous, 1998).
This can be contrasted with a definition of centralised systems, also provided by Crites and
Tchobanoglous (1998):
Centralised wastewater management, on the other hand, consists of conventional or alternative
wastewater collection systems (sewers) centralised treatment plants, and disposal/reuse of the
treated effluent, usually far from the point of origin, although the liquid portion and any
residual solids can be transported to a centralised point for further treatment and reuse.
It can be highlighted from the above definitions that decentralised wastewater systems are described as
systems installed and operated to deliver effluent/wastewater services near to the point of generation in
small to medium development areas. Traditionally, the main application of decentralised wastewater
systems is for servicing areas that are difficult to service with centralised sewerage systems due to
technical or economic considerations.
With the increasing awareness of water and energy conservation, decentralised systems are more often
implemented to reduce flows to centralised wastewater treatment systems and to reuse wastewater for
non-potable applications at the property level. An initiative, such as the Green Building Council of
Australia’s Green Star Rating system which allocates points for on-site wastewater treatment and
reuse, is increasing the use of decentralised approaches in commercial buildings.
Historically, the most commonly adopted decentralised wastewater systems involved a septic system
for collection and primary treatment and a leachfield for further treatment and disposal. A range of
advanced wastewater collection and treatment systems and technologies are available for safe
sanitation in small and medium communities. These systems are also applied in infill developments in
urban areas to promote effluent (reclaimed water) reuse on a fit-for-purpose basis. Reviews on these
advanced technologies can be found in Geolink (2005) and Landcom (2004).
Pinkham et al. (2004) highlighted opportunities to apply decentralised wastewater systems beyond the
usual applications to small-town and rural communities. They indicated that the optimal architecture
of wastewater systems should consist of a mixture of different scales of sewerage systems rather than
what is commonly available today.
2.2.
Features of Decentralised Systems
Decentralised systems are generally designed based on Integrated Urban Water Management (IUWM)
and Water Sensitive Urban Design (WSUD) concepts. A number of structural features can be used to
achieve IUWM and WSUD objectives, the selection of which is dependent on a large number of
factors including the type and scale of development, proximity to existing centralised services,
catchment conditions, climate, customer acceptance and allocation of financial resources (Sharma et
al., 2008).
A number of studies (Diaper, 2004; Tjandraatmadja et al. 2008) have described approaches used to
achieve IUWM and WSUD objectives. Typically, these approaches include features which could be
described as decentralised systems; they focus on the delivery of water and wastewater services at a
localised scale separate from centralised systems or in combination with existing centralised facilities
to reduce the load on freshwater resources and receiving environment.
2.2.1.
Rainwater Tanks
Rainwater tanks have been installed at individual dwellings and can also be used as communal tanks in
a small community. Based on regulatory requirements, rainwater can be used in the kitchen and can
also be used for hot water supply, toilet flushing, washing machine and garden irrigation, which can
contribute to significant reticulated water savings.
Definition of Decentralised Systems in the South East Queensland Context
Page 5
2.2.2.
Stormwater Systems
Stormwater is surface runoff. Given appropriate treatment, stormwater can be used as an alternative
water resource at subdivisional scales; however, the use of stormwater is currently still limited by
factors such as the area required for storage. However, methods such as stormwater Aquifer Storage
and Recovery (ASR) offer opportunity to store stormwater and recover it for reuse. Stormwater
systems such as on-site detention tanks, buffers, swales, bioretention devices and ponds are operated
mainly for environmental protection and enhancement.
2.2.3.
Greywater Recycling Systems
Greywater is sourced from the bathroom and laundry, and to a lesser extent, from the kitchen as
kitchen wastewater contains higher concentration of gross contaminants as well as fats, oils and
greases. Reuse of treated greywater can significantly substitute reticulated water for non-potable use.
An additional significant benefit from greywater recycling is the reduction of flow discharged to
sewers. The application of recycled greywater is dictated by the quality of its treatment. There are
many development examples demonstrating that greywater can be collected, treated and reused for
non-potable applications at each household, or collected from multiple dwellings, treated on-site and
reused for irrigation (Tjandraatmadja et al. 2008).
2.2.4.
Wastewater Recycling Systems
Wastewater is the used water from exiting dwellings, including greywater and blackwater carrying
toilet waste. On-site wastewater treatment systems at a small to medium scale have been reviewed
under Section 2.1. Treated effluent can be used in non-potable applications including garden irrigation,
and can also be used for toilet flushing after disinfection and potentially for household supply. The
end-use applications are influenced by the wastewater characteristics and treatment methods used. At
present, safe use of recycled wastewater still faces a greater challenge compared to greywater, due to
the need for more advanced treatment for the high levels of faecal microorganisms and the potential
presence of pathogens, persistent organic pollutants and pharmaceuticals (Tjandraatmadja et al. 2008).
2.2.5.
Demand Management Strategies
Demand management strategies are an important component of achieving water supply/demand
balance for an area. Demand management strategies reduce the total amount of water required to
service a population. Strategies can include design and planting of gardens and public open space to
minimise irrigation requirements, leakage management and encouraging water efficiency through
behavioural change and increased uptake of water efficient appliances. Mitchell and White (2003)
made the point that taking an integrated resource planning approach that considers opportunities for
reducing demand through water efficiency measures offers the lowest cost per unit volume and
provides the most sustainable way to obtain new water to meet population or environmental needs.
Table 1 and Table 2 summarise some of the typical developments, with a mixture of alternative water
features incorporated, that occur across Queensland and other Australian states respectively
(Tjandraatmadja et al. 2008; <<http://www.naiad.net.au>>). The tables illustrate a range of options
used to integrate these features in the management of water systems at small to medium scales. It is
interesting to note that most of the decentralised systems in Queensland (Table 1) are based in
residential developments for water and wastewater servicing, while in the other states, the application
of decentralised systems has also been extended to commercial developments. The provision of
various physical systems and end use of alternative water sources are also listed in Tables 1 and 2.
The decentralised systems and technologies that enable the reuse of alternative water sources such as
rainwater, greywater, wastewater and stormwater can be applied to a single dwelling or a cluster of
dwellings. For example, rainwater tanks are widely used at a residential lot level. The Australian
Bureau of Statistics reported that nearly 20% of Australian households have a rainwater tank installed,
while in Queensland, 22.1% of households reported rainwater tank as a source of water (ABS, 2007).
Permeable paving and reduction of paved areas are common stormwater techniques for source control
at the cluster scale (Argue, 2004). Systems for wastewater treatment may range from on-site septic
tanks to complex treatment trains including secondary treatment, membrane filtration and UV
disinfection (the selection of which will depend on the reuse and disposal conditions).
Definition of Decentralised Systems in the South East Queensland Context
Page 6
Table 1:
Queensland developments adopting the integrated urban water cycle management approach (Tjandraatmadja et al. 2008; <http://www.naiad.net.au>)
More information on these developments, including the drivers for adopting an integrated urban water cycle approach will be available in a concomitant report and can also be found
in Tjandraatmadja et al. 2008.
Development
Location
Type
Size
Physical Features
Beachmere Sands
Retirement Resort
Bribie Island, 45 km
north of Brisbane CBD
Resort
55 lots
Wastewater treated by KEWT system.
Capo di Monte
Mt Tamborine, in
Scenic Rim Regional
Council, 30 km west of
the Gold Coast
Residential
(Leisure village)
46 houses
Reticulated rainwater with bore water top up used for all in house usage except toilet; this system includes
filtration, UV and chlorination.
Onsite treatment of wastewater by immersed membrane bioreactor, UV and chlorination; used for toilet
flushing, garden irrigation and dedicated disposal areas.
Carindale Pines
east of Brisbane
31 Lots
25 kL rainwater tanks topped up with reticulated water for all uses including drinking.
Currumbin
Ecovillage
7 km west of
Currumbin Beach
Residential
144 lots
Rainwater tanks for all in-house usage except toilet.
Reticulated dual pipe sewerage system with recirculating textile filter, microfiltration, UV and chlorine to
provide A+ water for toilet, external use and fire fighting.
Healthy Home
Francis Avenue,
Mermaid Beach, Gold
Coast
Residential
1 house
Rainwater tanks topped up from Council mains, filtration and disinfection before use.
Grey water system for toilet flushing and garden irrigation.
Manly Ecovillage
Manly, Brisbane, 15
km south east of the
CBD
Residential
24 lots
Centralised rainwater tanks and treatment with topping up from council mains.
Centralised wastewater collection and treatment by immersed membrane bioreactor, UV, chlorination and
carbon filtration; the recycled water for toilet and garden.
Stormwater treatment via swales and bioretention basin.
Noosa North
Shore Resort
20 minutes from
Noosa's Hastings
Street Shopping
precinct
Resort
250
residences
Wastewater treated by aerobic membrane bioreactor to produce A+ effluent for toilet flushing, laundry,
garden watering and car washing.
Golf Estate
Bribie Island, 45 km
north of Brisbane CBD
Recreational
43 lots
Rainwater tank at each lot.
Dual pipe for future recycled water supply of toilets and external use such as lots and public open space
irrigation.
25 lakes for stormwater detention, peak flow reduction, nutrient and sediment containment.
Payne Road
Payne Road, the Gap,
Brisbane
Residential
22 lots
Rainwater tank at each lot for all in-house usage plus two centralised rain tanks which are topped up from
Council supply.
Greywater reuse from Biolytix system for subsurface irrigation.
Low infiltration gravity sewer for blackwater to council sewer.
Stormwater treatment via swales and bioretention basin.
PimpamaCoomera
Residential Estate
40km south of
Brisbane
Residential
50,000 lots
Rainwater topped up from Council mains, used for hot water and laundry. Recycled water for toilet
flushing, external household and public open space irrigation. Storm water treated by swales, bioretention,
wetland and basins for nutrient reduction. Wastewater collected using low infiltration gravity sewer treated
for reuse using membrane filtration and disinfection.
Sunrise 1770
10 km from the Town
of 1770, one and a half
hours drive north from
Bundaberg
Residential
172 lots
Rainwater tanks are topped up with potable water from the Reedy Creek Aquifer. All waste water is
reclaimed and treated to provide a secondary water supply for toilet flushing, exterior domestic uses, car
washing and fire fighting.
Definition of Decentralised Systems in the South East Queensland Context
Page 7
Table 2:
Developments adopting integrated urban water cycle management approach in states other than Queensland (Tjandraatmadja et al. 2008; www.naiad.net.au)
Development
Location
Type
Size
Physical Features
Forde development
ACT
Residential
1,100 blocks
Targeting 40% reduction in water usage by suggesting rainwater or greywater reuse.
Stormwater used to irrigate parks.
Brindabella Business
Park
ACT
Commercial
28 ha
Water conservation.
Rouse Hill
Sydney’s north-western
suburbs, 45 kilometres
from Sydney CBD
Residential
36,000 houses
Wastewater is treated in the recycled water treatment plant which involves secondary
aerobic systems with nitrogen removal, followed by tertiary treatment using
flocculation, clarification and sand filtration. The effluent is recycled via dual pipe
systems to households and is disinfected using UV and chlorination for toilet, garden
and car wash. Any excess effluent is chlorinated and then de-chlorinated before
being discharged to the constructed wetland.
Sydney Olympic Park
20 kilometres west of
Sydney CBD
Residential/
commercial
640 ha site (can
serve 20,000
people)
Sewer mining incorporating proven and emerging technologies such as biological
treatment, MF and RO.
Stormwater harvesting for local irrigation.
Mawson Lakes
12 km North of Adelaide
Residential and
commercial
4,000 lots
(650ha)
Recycled water is a combination of highly treated effluent from the Bolivar
wastewater treatment plant and of stormwater harvested in Salisbury. Treatment at
the Bolivar wastewater treatment plant includes biological nutrient removal, dissolved
air floatation and filtration, while stormwater is treated in a series of wetlands. The
combined reclaimed water is then disinfected before being recycled via dual pipe
system for toilet, car washing and garden watering. Surplus stormwater is stored in
the local underground aquifer for future reuses.
Parfitt Square
City of Charles Sturt,
5km North West of
Adelaide
Recreational
(public open
space).
0.6 ha
Stormwater retention for aquifer recharge and irrigation. Stormwater treated using
gross pollutant and sediment traps, infiltration swale, gravel based sub-surface
wetland.
New Haven Estate
18 kilometres northwest of Adelaide CDB
Residential
62 lots
Dual pipe recycling for toilet and irrigation.
Tertiary wastewater treatment with activated sludge, sand filtration and UV.
St Elizabeth Church
Oaklands Park, 10 km
South West of Adelaide
Redevelopment of
car parks and
tennis courts
0.3 ha
Stormwater quality source control, grass-pave for hard standing area and soakways.
Aquifer recharge and reuse in Church landscaped area.
New Brompton Estate
Brompton, 5km North
West of Adelaide
Residential
15 lots
Roof runoff management – collection of roof runoff from 15 cluster houses and
diverted to infiltration trench for aquifer recharge.
Municipality of Brighton
TAS
Stormwater
Harvesting
80 ha catchment
Wastewater collected from households is biologically treated to secondary quality in
the Brighton Wastewater Treatment Lagoon and the Green Point Wastewater
Treatment, before being recycled for agricultural reuse.
Aurora (Epping)
Epping, VIC
Residential
8,500 lots
Rainwater tanks and rain gardens in allotments.
Wastewater collected from households is treated using aerobic biological system plus
sand filtration, ultra-filtration, UV and chlorination to produce Class A recycled water,
prior to reuse through dual pipe for toilet and gardens. Stormwater is treated using
bio-retention trenches and swales.
Definition of Decentralised Systems in the South East Queensland Context
Page 8
Development
Location
Type
Size
Physical Features
Brighton Eco
Townhouses
Brighton, VIC
Residential
2 townhouses
Rainwater usage for toilet and garden. Rainwater from entire roofs, decks and paved
pathways collected.
Docklands Business
Precinct
VIC
Commercial
200 ha
Stormwater harvesting, treatment and reuse for irrigation. Stormwater quality control,
such as bioretention swales and wetlands. Development guidelines encourage
initiatives such as on-site greywater recycling.
60L Building
60 Leicester Street,
Carlton, VIC
Commercial
3,375 m2 area
Use of water efficient fixtures, waterless urinals, low flush volume toilets.
Rainwater use to replace mains water (90% less usage).
Reclaimed water for toilet and roof garden irrigation. Wastewater treatment system of
biofiltration and clarification.
Sharland Oasis
Geelong VIC
Residential
1 house
Rainwater is for all non-potable household uses. Grey water is used for garden
irrigation after being treated in the patent system, namely Biological Peat Cartridge
and Sac System, which basically uses a peat as a biofilm carrier.
Investa Property Group
VIC
Commercial
9 properties
across
Melbourne
Waterless urinals, water flow restrictions to taps, hand basins and showers. 25%
reduction in water consumption.
Council House 2
VIC
Commercial
12,536 m² (floor
area)
Rainwater collected and used to supplement water mains. Sewer mining treated
effluent supplies irrigation, cooling, toilet flushing and other Council water needs, e.g.
equipment for street washing and open spaces. The sewer mining process involved
ultra-filtration, desalination using RO systems and disinfection.
Beachridge Estate
WA
Residential
1,000 lots (2,000
ha)
Stormwater focussed development to maintain predevelopment catchment hydrology.
Application of drainage swales landscaped in road median strips and opportunities
for pollutant reduction. Public open space used as stormwater retention, detention
and infiltration.
Bridgewater South
Estate
WA
Residential
100 lots
The development is mainly stormwater focussed. Structural controls for stormwater
infiltration, retention and detention at source through infiltration swales and vegetated
buffers are provided. The stormwater system also includes soakwells. No direct
storage.
Lakelands Private
Estate
WA
Residential
2,500 lots
The development is devoted to sustain the natural wetlands and thus is stormwater
focussed. The on-site infiltration of stormwater through basins, drains and swales are
integrated with landscape of public open spaces. Bore water for POS.
Definition of Decentralised Systems in the South East Queensland Context
Page 9
Cluster scale options for decentralised water and wastewater services can be a combination of tools
applied either at single household or communal scale, or both. The advantage of larger scale cluster
systems, in comparison to centralised systems, is a greater level of control of the quality and quantity
of water/wastewater entering the systems, which increases the flexibility and simplicity of the
treatment process. Cluster scale systems also offer economies of scale (Naji and Lustig, 2006), as it
will often be more efficient for a number of households to invest in and utilise a decentralised
technology than for each household to own and operate its own system.
In subdivisional scale developments, rainwater tanks and greywater can be used in single household or
clustered homes as the current techniques and technologies are more appropriate to these levels.
Typical models for wastewater servicing at a subdivision scale include collection from individual
homes and transport to a wastewater treatment system within the development area for treatment.
Treated effluent is provided to households for non-potable applications via a dual pipe system.
Subdivision developments, such as Pimpama Coomera and Rouse Hill (Tables 1 and 2), have adopted
a combination of rainwater, greywater and wastewater systems.
2.3.
Consultation with Water Professionals in SEQ
An online questionnaire was developed to elicit information from water professionals familiar with the
SEQ context. Participants were asked their opinions on how to define decentralised systems, including
what physical features should be included, what is unique to decentralised systems in SEQ and what
system scale is appropriate. A semi-structured interview approach was also undertaken for selected
participants. The semi-structured interview enabled the interviewer to collect information on specific
areas, while also allowing the interviewer to take an active role in the process and seek additional
insights when required. The water professionals who participated were not necessarily representative
of the whole industry, but were approached based on their perceived knowledge and involvement in
decentralised systems in the SEQ context. The privacy of individuals was protected through
anonymity, and answers were not attributed to a specific organisation. A thematic analysis of
questionnaire and interview results was undertaken to identify common themes and descriptors used
for decentralised systems.
Professional staff from water authorities were contacted for their comments and views. Authorities
included: Brisbane City Council, Gold Coast City Council, Toowoomba City Council; state
government, including the Department of Infrastructure and Planning, EPA, Natural Resources and
Water and Queensland Health; and consultants in water business based in Queensland, such as Bligh
Tanner, Econova, GHD, Maunsell, WBM, Worley Parsons and Central Queensland University. Their
comments are summarised as follows:

Decentralised systems will need to include both decentralised water and wastewater systems.
Current practitioners consider decentralised systems to be part of an integrated approach
in managing urban water resources that crosses traditional functional boundaries.




Keywords in the definition of decentralised systems should include ‘fit-for-purpose’ and ‘close
to the source(s)’.
System features need to be dictated by the context, local characteristics and each individual
project’s scale and needs. Technologies can range across a diverse suite of measures such as
harvesting and using rainwater, greywater recycling systems and partially or fully on-site
wastewater treatment. Technology selection should be defined by the water/effluent quality
required which implies appropriate robustness, operation and maintenance and risk management
strategies.
The system scale can range from a small development to a relatively large development such as
a small suburb, depending on the characteristics of the development areas. The difficulty in
incorporating scale in the definition of decentralised systems was highlighted during the
discussion.
Many of the descriptors (such as volume, scale and low cost) under the historical definition of
on-site systems are too limiting when applied to today’s understanding of decentralised systems.
These descriptors can be used to describe a part, rather than the whole, of the system, as per
today’s understanding and greater focus is made on tailoring systems to each individual target
area.
Definition of Decentralised Systems in the South East Queensland Context
Page 10

Specific characteristics of decentralised systems in the context to SEQ were not highlighted for
inclusion in its definition.
2.3.1.
Consultation Results: Aspects of Decentralised Systems
Interviewees were asked to define what constitutes a decentralised system. In addition, they were
asked about the relevance of terms which are traditionally alluded to in the definition of decentralised
systems such as, volume of water/wastewater processed by the systems, size of population or area
serviced, economic cost, integrated water management, etc.
The definitions of decentralised systems provided by interviewees highlighted the connections with
broader sustainability objectives such as reduced reliance on imported water and the interactions
between water, wastewater and stormwater services. The definitions adopted by the professionals are
expansive, focusing on the wider water cycle, which is consistent with an integrated urban water
management approach. However, the need for urban water regulatory and management frameworks to
evolve to meet the needs of decentralised systems was not specifically raised during the interview
process.
The definitions adopted by professionals include a range of common concepts: decentralisation of
infrastructure; function; and the roles of scale, sustainability and proximity to source. These and other
aspects mentioned in the definitions provided during the consultation were further explored.
(a)
Infrastructure
One of the most common descriptors used for defining decentralised systems infrastructure was
reduced dependency, or differentiation from the traditional centralised and linear provision of services,
in recognition of a wider range of service models and resources. At the same time, it was recognised
that decentralised systems do not necessarily have to be closed loop or stand-alone in all aspects. In
many cases, decentralised systems are integrated with existing centralised services, which provide
service reliability while addressing sustainability objectives such as reduced demand on imported
potable water. A transition to an integrated urban water management approach, in comparison to a
conventional approach, involves increased linkages and interdependencies between water, wastewater
and stormwater infrastructure. Some of the descriptors of decentralised infrastructure mentioned by
participants included: stand-alone; non-linear; not restricted to a single source or treatment location;
able to utilise multiple sources including large network collection/reticulation; partially or not
centralised, but not necessarily a closed system.
(b)
Function
The responses highlighted that decentralised systems are aimed at fulfilling a function (mainly
provision of water and safe management of waste) and should be designed accordingly. The details of
specific systems will vary with each case, but are typically based on scale, context and required water
quality. As with centralised systems, reliability and public health risk mitigation are essential to the
function of decentralised systems. Respondents did not restrict function discussions to wastewater
management. They extended the concept to include all aspects of the water cycle: water supply and
wastewater management, as well as different streams (greywater, rainwater, stormwater, treated
effluent, etc).
(c)
Recycling and Sustainability
Sustainability was identified as a clear differentiator between centralised and decentralised systems
with a greater emphasis given to the environmental and sustainability function provided by the
systems, e.g. water reuse and reduction of bulk water transfer. Responses indicated a heavy emphasis
on the optimisation of opportunities for recycling and sustainability as a characteristic of decentralised
systems. Recycling and sustainability could refer to the provision of recycled water and reuse
opportunities for meeting water demand. Decentralised systems, as part of an integrated urban water
management approach, consider broader sustainability goals in evaluating options for servicing an
urban area. The inclusion of sustainability aspects in the definition implies that the respondents
recognise that the systems are to be evaluated over their whole life cycle, including operating
expenditure and environmental costs over the total life cycle of the system, such as embodied and
operational energy demands, nutrient discharge and recovery, and material consumption.
Definition of Decentralised Systems in the South East Queensland Context
Page 11
(d)
Proximity to Source
The current definition adopted by interviewees emphasises proximity to source as a major
characteristic. Operation within a restricted system envelope was highlighted among responses, and
was associated with the minimisation of bulk transfer over distance or inter-basin, reuse or treatment at
or near the point of generation with minimisation of the ecological footprint. For example:
“Meeting water demand and managing waste within area of generation”.
“Water supplied in an area to be reused in the same areas”.
“Produces drinking / non-drinking water for local reuse”.
“Minimise energy associated with long distance pumping”.
(e)
Scale
The responses indicated that components of the system will vary based on specific context or scale.
Decentralised systems can encompass a range of scales from allotment (high rise/house) to
neighbourhood, suburb, cluster, etc, with unique characteristics for each project.
(f)
Technology
Decentralised systems imply a certain level of technology and treatment based on the required end-use
and purpose of the system. The responses indicated that such systems could adopt a range of
technological options. These are not restricted to wastewater alone and can include water supply,
treatment of different wastewater streams and control of bulk transfer.
Greater emphasis was placed on the tailoring of a system to the particular needs of a site/catchment
and the design and provision of services based on specific ecological, physical, climatic and
geographical aspects. Some responses also mentioned the role of technology management models in
the definition.
(g)
System reliability
Implicit in the definitions was the need for system reliability in order to provide a minimum level of
service to customers. The design and operation of decentralised systems need to take a risk
management approach that considers the consequences of system failure in terms of public health and
environmental impacts. In cases of where there is a high consequence of failure, connection to
traditional networks may be required as a fall -back position.
Decentralised systems fulfil the same functions as centralised systems in the provision of water
demand and safeguard of public health in the disposal of wastewater. Requirements for reliability and
risk management in the provision of services are also applicable in such systems.
(h)
Independence
Overall, professionals defined decentralised systems as systems with a greater degree of independence
from single sources and centralised water/wastewater provision. The degree of independence can
range from a stand-alone closed loop to a semi-integrated system.
Some of the respondents differentiated between on-site systems and decentralised systems. ‘On-site’
systems generally refer to allotment scale systems, while decentralised systems can encompass a wider
range of scales.
Respondents often defined on-site systems based on the volume of wastewater generated and
occupancy rate as they have traditionally referred to allotment wastewater management. Such
parameters have a lesser impact as the scale increases (medium and larger schemes); yet, as one of the
respondents mentioned:
Some guidance in regards to size might be necessary to assist in the identification of projects
that might be better incorporated in centralised service provision.
Definition of Decentralised Systems in the South East Queensland Context
Page 12
3.
SCALE OF DECENTRALISED SYSTEMS
Decentralised systems can be implemented in a wide range of development scales, including
allotments, a cluster of houses and subdivisions. As described in Section 2.1, the guidelines for
decentralised wastewater systems planning and design in SEQ are available for a single house, a
development, up to a population of 1000. Considering an average household size of 2.6 persons, a
decentralised wastewater system can be provided for a development of approximately 380 dwellings.
The list of existing developments with decentralised systems (listed in Table 1 and Table 2) ranges
from just one house (e.g. Healthy Home in Gold Coast and Sharland Oasis in Geelong) to as large as
50,000 lots in Pimpama-Coomera residential estate (Gold Coast). As listed in Table 1, the
developments with decentralised systems in Queensland vary from single allotment to a maximum of
250 lots, with an average of nearly 80 lots per development. The Pimpama-Coomera residential estate
has not been included in this assessment due to the uncommon nature of the Greenfield development.
Similarly, considering Table 2, the developments in other States vary from single allotments to 8,500
lots (planned Aurora capacity) with an average of nearly 1,700 lots. The Rouse Hill development of
36,000 lots is not considered due to its extensive nature.
Based on the above, developments up to 8,500 lots have been designed with decentralised systems. If
the developments such as Pimpama-Coomera and Rouse Hill are included in scoping the scale of
decentralised systems, the decentralised systems are able to provide services up to any scale. Thus, it
can be concluded that the scale is not a determining issue in providing decentralised services either in
isolation or in combination with centralised systems.
For demonstration purposes, Figure 2 depicts the building scale wastewater reuse and Figure 3, the
cluster scale sewer mining and reuse. Figure 4 highlights development scale water and wastewater
servicing options. Decentralised systems, such as those in Figures 2 and 3, can form part of a satellite
wastewater system as described by Gikas and Tschobanoglous (2009), which generally occurs in the
upper part of a wastewater system and can be used to reduce loads on centralised facilities and offer
local opportunities for reuse.
Figure 2:
On-site wastewater system (Source: Sharma et al, 2005)
Definition of Decentralised Systems in the South East Queensland Context
Page 13
Figure 3:
Cluster scale reclaimed water reuse system (Source: Sharma et al, 2005)
Figure 4:
Development scale decentralised systems
Definition of Decentralised Systems in the South East Queensland Context
Page 14
4.
DEFINITION OF DECENTRALISED SYSTEMS
Based on a review of the literature, the definition of decentralised systems from Crites and
Tchobanoglous (1998) was considered suitable for adaptation, as it incorporates the integration
between different water services and the varying scales that decentralised systems operate at.
Furthermore, it captures the linkages that can occur with an existing centralised system:
Decentralised systems can be defined as the collection, treatment and use of rainwater, stormwater,
groundwater or wastewater at different spatial scales, from individual homes, clusters of homes,
urban communities, industries, or built facilities, as well as from portions of existing communities
either independent from or as part of a larger system.
However, the above definition has been modified to reflect that decentralised systems are provided to
minimise environmental impacts caused by the increase in demand on fresh water resources and
discharge of waste loads to a receiving environment (natural water systems, soil and atmosphere). The
following generalised definition is suggested for adoption:
Decentralised systems can be defined as systems provided for water, wastewater and stormwater
services at the allotment, cluster and development scale that utilise alternative water resources;
including rainwater, wastewater and stormwater; based on a ‘fit for purpose’ concept. These
systems can be managed as standalone systems, or integrated with centralised systems. Wastewater
streams are partially or completely utilised at or close to the point of generation.
At the cluster and development scale:
Stormwater is also managed as part of an integrated approach that aims to control the quality and
quantity of runoff at or near the source to minimise the impact of the development on the natural
ecosystem.
In relation to SEQ, no specific characteristics were identified for inclusion in the definition of
decentralised systems.
Highly variable scales of development with decentralised systems can be noted from the existing
examples; therefore, it is inappropriate to specify any particular scale of development in defining
decentralised systems. The suggested definition is simply based on the concepts of integrated urban
water management applied to developments for the provision of water, wastewater and stormwater
services such that the demands on freshwater sources and wastewater flows to receiving environments
are reduced.
5.
CONCLUSION
Decentralised systems with IUWM and WSUD concepts are being planned and implemented for new
and future urban developments, either as separate facilities or in combination with a centralised
system. This is due to an increase in urbanisation and industrialisation, resulting in unsustainable
pressure on freshwater resources and the wastewater receiving environment.
The following general definition of decentralised systems is recommended for adoption in the SEQ
Decentralised Systems project:
Decentralised systems can be defined as systems provided for water, wastewater and stormwater
services at the allotment, cluster and development scale that utilise alternative water resources;
including rainwater, wastewater and stormwater; based on a ‘fit for purpose’ concept. These
systems can be managed as standalone systems, or integrated with centralised systems. Wastewater
streams are partially or completely utilised at or close to the point of generation. At cluster and
development scale, stormwater is also managed as part of an integrated approach that aims to
control the quality and quantity of runoff at or near the source to minimise the impact of the
development on the natural ecosystem.
An attempt was made to estimate the scale of decentralised systems in terms of development size. It
was concluded from the size of existing developments designed with WSUD, that it varied from a
single lot to 8,500 lots or even higher. In summary, the process rather than the scale governs the
definition of decentralised systems. Furthermore, the systems and technologies for providing
decentralised water, wastewater and stormwater services can vary based on the scale of development
and the conditions of the locality to which they are applied.
Definition of Decentralised Systems in the South East Queensland Context
Page 15
REFERENCES
ABS (2007) 4602.0 – Environmental issues: People’s views and practices, March 2007. Australian Bureau
of Statistics.
Argue J. 9ED.) (2004) Water Sensitive Urban Design: Basic procedures for ‘source control’ of stormwater,
University of South Australia.
AS/NZS 1547:2000 Onsite domestic wastewater management (Standards Australia and New Zealand,
1998).
Crites R.. & Tchobanoglous G.. (1998) Small and Decentralized Wastewater Management Systems,
McGraw-Hill.
Danielson, T. (2008) Distributed wastewater management: A practical, cost-effective and sustainable
approach to solving wastewater problems, Water, Environment and Technology, 20 (2).
Diaper, C., Sharma, A. and Tjandraatmadja, G. (2007). Decentralised water and wastewater systems.
Transitions: Pathways Towards Sustainable Urban Development in Australia, edited by Newton, P.,
CSIRO Australia Publishing and Springer, The Netherlands.
Diaper C., Tjandraatmadja G. and Kenway S. (2007) Sustainable subdivions – review of technologies for
integrated water services. CSIRO Technical Report.
Geisinger, D. and Chartier, G. (2005) Managed onsite/decentralised wastewater systems as long-term
solutions, Clearwaters, 35, pp. 6 – 11.
Geolink (2005) Clunes Wastewater - Assessment of Onsite and Community-Scale Wastewater
Management Options. http://www.geolink.net.au/infocentre/index.html.
Gikas, P. and Tchobanoglous, G. (2009) The role of satellite and decentralised strategies in water resources
management, Journal of Environmental Management 90, pp. 144-152.
Guidelines for the Queensland Plumbing and Wastewater Code (Department of Infrastructure and Planning,
Queensland, 2007).
Interim Final Queensland Guidelines for Decentralised Wastewater Systems (2007), Queensland
Government EPA and Bligh Tanner (unpublished).
Landcom (2006) Wastewater reuse in the Urban Environment: selection of technologies.
Mitchell, C. and White, S. (2003) Forecasting and backcasting for sustainable urban water futures, Water
30 (5), pp. 25 – 30.
Naji, F. and Lustig, T. (2006) On-site recycling: a total water cycle management approach, Desalination
188 (1-3), pp. 195-202.
Pinkham., R.D., Hurley, E., Watkins, K., Lovins, A. B., Magliaro, J., Emier, C. and Nelson, V. (2004).
“Valuing Decentralized Wastewater Technologies - A Catalog of Benefits, Costs, and Economic
Analysis Techniques”, Rocky Mountain Institute, Snowmass CO, USA.
Sharma, A.K., Gray, S., Diaper, C., Howe, C. and Liston, P. (2008). “Assessing Integrated Water
Management Options for Urban Developments – Canberra case Study” 5(2), 147-159, Urban Water
Journal, UK.
Sharma, A., Grant, A., Gray, S. and Mitchell G. (2005). “Yarra Valley Water: Sustainability of alternative
sewerage and water servicing options for Kalkallo and Box Hill developments”.
Tchobanoglous, G (1996) Appropriate technologies for wastewater treatment and reuse, Water, 4
(July/August 1996), pp. 24-27 (referred in Crites and Tchobanoglous, 1998).
Tjandraatmadja G., Cook S., Sharma A., Diaper C., Grant A., Toifl M., Barron O., Burn S. and Gregory A.
(2008) ICON water sensitive urban developments. CSIRO Technical Report.
Unesco (2008), http://www.ihe.nl/Education/Short-courses/Regular-short-courses/Decentralised-WaterSupply-and-Sanitation, last accessed 20/10/2008.
USEPA (2005) Decentralised wastewater treatment systems, A program strategy, publication, document
no. EPA 832-R-05-002, USEPA Publications Clearinghouse, PO Box 42419, Cincinnati, OH 45242.
http://www.epa.gov/owm/septic/pubs/septic_program_strategy.pdf.
Wilderer, P.A. (2001) ‘Decentralised versus centralised wastewater management’ in Decentralised
sanitation and reuse, concepts, systems and implementation edited by Lens, P., Zeeman, G. and
Lettinga, L.
Definition of Decentralised Systems in the South East Queensland Context
Page 16
Urban Water Security Research Alliance
www.urbanwateralliance.org.au
Fly UP