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A Triple Bottom Line (TBL) approach to
decision making
WRRF-14-03 TBL Framework
Dr. Michalis Hadjikakou
Sustainability Assessment Program
Water Research Centre
University of New South Wales, Australia
30 August 2016
Broken Hill, LGNSW Water Management Conference
Water scarcity and need for a framework
Water scarcity already a problem in parts of Australia and the US
Challenge is to ensure sustainable supply augmentation
‘New’ options such as potable reuse added to the mix
Need for a holistic framework for comparing alternative water supply
options (WSOs)
Lake Hume, 2007
(Source: Wikipedia)
Lake Merindee, 2015
(Source: ABC News)
WRRF-14-03 TBL Framework Development
Project funded by the Water Reuse Research
Foundation (WRRF) the AWRCoE
Partnership between Hazen & Sawyer and
UNSW plus 4 partners
Coliban Water
Port Macquarie-Hastings
Tampa Bay Water
Orange County Water
Task 2
TBL Framework
Development
Task 1
State of the
Industry
Assessment
Task 3
Methodology and
model development
Task 4
Deliver Excel tool
and case studies
February 2015 – August 2016Workshops
Industry surveys
LCA data
MCDA
TBL – basic concept and framework
Holistic definition of sustainability
Basic concept is to ensure economic, social
and environmental criteria are optimised
Various methodologies used e.g cost-benefit
analysis, life cycle assessment
No method is perfect but monetizing all
costs and benefits is oversimplification
Need to capture direct and indirect impacts
Avoid bias by separating TBL results from
the multi-criteria decision analysis
WSAA (2008) Sustainability Framework
• Used to guide our project
but also should be used to
guide utilities using our
tool!
• Phases 3 and 4 completed
through workshops and
literature
• Phase 5 represents the core
of our analytical framework
• Iterative and dynamic
process
• MCDA officially starts at the
end of in phase 5
Final framework WSOs and criteria
• Stormwater harvesting
• Extension of existing supplies
• Demand management
• Dual pipe/purple pipe
• Water imports
• Direct Potable Reuse (DPR)
• Indirect Potable Reuse (IPR)
• Desalination
• New dam (reservoir)
• Groundwater pumping
Wo
rksh
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rveys
Water Supply Options
Other considerations – functional unit and scope
• Context-specific criteria
• Quantitative & qualitative data
• Electricity mix
• Chemicals
• MCDA algorithm
• Functional unit ($ or quantity)
• User inputs and data available
• Regional variations
• Conveyance
• Sludge disposal
Wo
rksh
op
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rveys
Key considerations
0 2 4 6 8 10 12 14
No, prefer costs
Indifferent, could do either
Yes, prefer physical/other units
Did not respond
Costs or physical units preference
0 2 4 6 8 10
No, prefer costs
Indifferent, could do either
Yes, prefer physical/other units
Did not respond
Costs or physical units preference
AUS (n=24)
US (n=44)
Goal: Feasible inputs, meaningful outputs
Customised TBL Framework
Hybrid LCA model (input-output modelling +
process-based LCA)
Separate USA and Australia economy and
social, environmental extensions
Includes operation and construction phase
Localised impacts and qualitative criteria are
considered outside hybrid LCA (user-defined)
Scale and scenario flexibility
MCDA with user-defined weightings used to
compare water supply options
2. MATLAB FUNCTION
c. Life cycle and unit cost estimation
d. Carbon emissions from electricity (state-level)
a. Detailed cost breakdown based on unit process cost curves
b. TBL impacts(EE-MRIO & LCIA)
e. Additional conveyance, sludge disposal and on-site energy impacts
1. INITIAL INPUT SCREEN
Enter AUS postcode Select unit processes Specify process size Chemical requirements Set conveyance options Onsite electricity & fuel Repeat for up to 5 WSO
configurations
QUANTITATIVE CRITERIA ESTIMATED
3. PERFORMANCE TABLE
Enter social criteria (semi-quantitative)
Add criteria (optional) Set all quantitative and
qualitative criteria weights
5a. VISUALISATION OF UNWEIGHTED RESULTS
(RADAR CHART)
4.MCDA VBA
FUNCTION
(EVAMIX)
5b. MCDA RESULTS OVERALL WEIGHTED WSO PERFORMANCE
LEGEND
User inputsFunctionsSub-functionsOutputs
FINAL MODEL OVERVIEW
1a. Initial Input Screen
1. INITIAL INPUT SCREEN
Enter postcode
Select unit processes
Specify process size
Chemical requirements
Set conveyance options
Onsite electricity & fuel
Repeat for up to 5 WSO
configurations
User asked to enter postcode and
select unit processes and size
User inters proposed capacity and
can also set different plant flow
rate
1b. Initial Input Screen
1. INITIAL INPUT SCREEN
Enter postcode
Select unit processes
Specify process size
Chemical requirements
Set conveyance
options
Onsite electricity & fuel
Repeat for up to 5
WSO configurations
Extra inputs such as conveyance,
electricity sources and on-site fuel
Detailed list of commonly used
chemicals and also option to enter
own costs
2. Matlab Function – main model
2. MATLAB FUNCTION
c. Life cycle and unit cost estimation
d. Carbon emissions from electricity (state-level)
a. Detailed cost breakdown based on unit process cost curves
b. TBL impacts(EE-MRIO & LCIA)
e. Additional conveyance, sludge disposal and on-site energy impacts
a. Costs essentially the sum of all
unit processes (generalised
formulae)
y = ax3 + bx2 + cxn + dln(x) + e
b. Costs fed into hybrid LCA model
c. Costs adjusted to present day
d. Electricity grid adjustment
e. Additional impacts
Supply chain impacts calculated
QUANTITATIVE CRITERIA ESTIMATED
3. Performance Table
Model results pre-populate the table with calculated values
User enters all other values (yellow cells) and specifies indicators weights
(grey cells) and tool is then ready to run
4. MCDA function
Simple Aggregated Weights (SAW) commonly used is flawed
EVAMIX algorithm used to combine numerical and categorical variables
Choosing weights is an important part of the process – needs to be as
informed as possible
Unweighted results also useful and informative…
5. Results
First output is a radar chart of comparative results for all criteria
Final results provide a recommendation – WSO 1 is better in this example
Tool user can also refer back to the results table
a. Unweighted results b. Final MCDA results
Conclusions – a TBL tool for the future
First attempt at a sophisticated analytical tool to help decision-making
Many possibilities to improve model and tool - ‘BYO’ option?
Decision-making considerations
Important to consider all evidence and re-iterate process frequently
Weighting criteria needs to be an important and transparent aspect of the
decision-making process
TBL tools can be used to shortlist or compare options but is not meant to
provide final answer
THANKS FOR YOUR ATTENTION
If you have any questions or feedback, please email
Dr. Michalis Hadjikakou, at [email protected]
A Triple Bottom Line (TBL) approach to
decision making
WRRF-14-03 TBL Framework
APPENDIX
0 5 10 15 20 25
Reservoir - dam
River impoundent
Reservoir - ASR
Groudwater pumping
Surface water pumping
Desalination (ocean)
Desalination (brackish)
Recycled water
Direct Potabe Reuse
Indirect Potable Reuse
Rainwater tank
Stormwater harvesting
Demand management
Water imports
Number of utilities
Cost data availability for different water supply options (US)
Yes - either total or unit costs No, could not input any cost data
Q.8. When using the TBL tool, would your utility be able to input the total or unit
costs for each WSO currently used or planned to be used?
Q.9 & 10 For the total or unit cost data of WSOs (current or future), into what level of detail would you be able to break down those costs?
These questions are meant to provide an indication of the level of detail the utilities are comfortable working with when it comes to cost data. The results of these questions are crucial when it comes to
designing the user input screen of the tool interface.
0 5 10 15 20 25 30 35 40
Current WSO
Future WSO
Number of utilities
Cost breakdown preference
Breakdown by input/component Breakdown by unit process
Other Did not respond