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

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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

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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 m.hadjikakou@unsw.edu.au

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