Advancing
our journey to net-zero
Acknowledgements
This document is an initiative of the Climate Change Special Interest Group. Matt Findlay of Brian Perry Civil has led the development of the document with input from Catherine Taiapa of Armatec; Kate Parkinson and Alida van Vugt of PDP; Mark Boniface, Sarah Shallcross and Nick Dempsey of Mott MacDonald; Kevin Manalo of Altacon; Jackson MacFarlane of Hynds; Eliza Cowey of Aecom; Yatin Praveen of Wellington Water; and Quintin Prinsloo of CreativeMinds.
Copyright © Water New Zealand
Reproduction, adaptation or issuing of this publication for educational or other non-commercial purposes is authorised without prior permission of Water New Zealand. Reproduction, adaptation or issuing of this publication for resale or other commercial purposes is prohibited without the prior permission of Water New Zealand. Permission can be sought by contacting Water New Zealand at enquiries@waternz.org.nz.
Disclaimer
Water New Zealand and individual contributors make no representations and give no warranties of any kind, whether expressed or implied, concerning the information contained in this document. The document and all information contained in it are provided “as is” and subject to change without notice. Any risk arising out of its use remains with the recipient. Water New Zealand and individual contributors are not responsible for the results of any actions taken on the basis of information in this guideline or any loss, damage, costs or expenses of any kind that may arise in any way out of, or result from, any use of material or information in this guideline.
Published by
Water New Zealand | PO Box 1316, Wellington 6140 | P: +64 4 472 8925 | E:enquiries@waternz.org.nz | W: www.waternz.org.nz
Publication date: February 2025
ISBN: 978-1-0670357-4-7
Image credit: The southern kōura (Paranephrops zealandicus), © John Barkla, inaturalist: https://inaturalist.nz/photos/43476297. This photo is licensed under https://creativecommons.org/licenses/by/4.0/
We chose the kōura, a native New Zealand crayfish, as the motif for this guide because it shares several traits with embodied carbon in our water sector. The kōura, a scavenger that cleans our streams, accumulates materials to grow its shell over time and, like embodied carbon, stays hidden unless carefully tracked.
1. Introduction
The water industry contributes to the sustenance of life by providing essential water, wastewater, and stormwater services. Aligning with aspects of the principle of Kaitiakitanga, our service delivery can assist us to protect and enhance the mauri (life force) of the environment and our communities.
Our industry is on a journey to introduce carbon consideration and reduction to both operational and embodied carbon associated with water services, while maintaining the mauri of water. This document shares information we have gathered in the embodied carbon space to allow us to better incorporate embodied carbon considerations into our infrastructure sustainability and design
This document builds on concepts introduced by Navigating to net zero – Aotearoa’s water sector low-carbon journey (www.waternz.org.nz/navigatingtonetzero) and seeks to advance New Zealand’s progress to align with a thriving climate resilient future.
Navigating to Net Zero reminds us that Aotearoa New Zealand is unique. Local knowledge provides important guidance, values and practical considerations to the water sector in this country and decision makers can evaluate the results of embodied carbon calculations alongside community-based needs and Māori frameworks in a way that upholds Te Tiriti o Waitangi.
Both locally, and around the world, there is a growing body of knowledge and resources to support professionals seeking to reduce the embodied carbon. This document aims to bring together these sources of information, with guidance that is specific to both water and the Aotearoa New Zealand context, to help people and organisations working with or supplying, water, wastewater and stormwater industry in Aotearoa New Zealand to get started in this topic. This document is not designed to be an exhaustive explanation of embodied carbon calculations or actions but rather to stimulate thought and positive activity across the Aotearoa water community.
2. Who is this for?
This guide has been prepared for Water New Zealand members, industry professionals, organisations and interested participants involved across the water industry in Aotearoa New Zealand getting started in understanding embodied carbon. Water New Zealand believes that a common understanding of this knowledge will assist industry participants to align our efforts and accelerate progress. It is to assist those getting started, to encourage those on the journey to continue, and to prompt ideas for areas needing further development.
The key to this continuing journey is engaging our people. As we work together to slow the drivers of climate change, we each need to build a collective response, support each other to see the gaps in our current knowledge and learn new ways of thinking, acting and relating.
We can all act in our own spheres of influence, support others on the journey, and hold the door open for others to get started. Together we can create the real change we require in our organisations, and our ways of working and living.
We hope you can use this document to prompt new relationships, conversations, and consider new approaches to make change. Then share with others to develop our people’s skills, experience and knowledge of this area.
He aha te mea nui? Māku e kii atu, he tāngata, he tāngata, he tāngata.
What is the most important thing in the world? Well, let me tell you, it is people, it is people, it is people.
Whakatauākī - Sir Apirana Ngata
3. Why is it important?
Every person, and every living organism, in every country in every continent will be impacted in some shape or form by climate change. Climate change is caused by human activities and threatens life on earth as we know it. With rising greenhouse gas emissions, climate change is occurring at rates much faster than anticipated. Its impacts can be devastating and include extreme and changing weather patterns and rising sea levels (United Nations, 2024).
Contributing to global efforts to tackle climate change
Around the world governments are setting targets to outline each country’s contributions to limit the most devastating impacts of climate change. Aotearoa New Zealand is a signatory to the Paris Agreement, the global agreement on Climate Change adopted by the United Nations. The key purpose of the Agreement is to keep the global average temperature well below 2°C above pre-industrial levels, while pursuing efforts to limit the temperature increase to 1.5°C. This average was breached for 11 consecutive months in 2023 (Climate Copernicus, 2024).
“The scale and urgency of carbon reduction in the infrastructure and building sectors has not been at the pace needed against the backdrop of the climate crisis.” – PAS 2080:2023
Aotearoa New Zealand contribution to global efforts
In Aotearoa New Zealand, our first Nationally Determined Contribution (NDC1) commits to reducing greenhouse gas emissions by 50 per cent below 2005 levels by 2030. The Climate Change Response (Zero Carbon) Amendment Act sets our requirements under the Paris Agreement into law. Aotearoa New Zealand’s first Emissions Reduction Plan (ERP) requires the Government to reduce emissions across the economy. Emissions budgets were set in 2022 which act as stepping stones to reach 2050 emissions reduction targets.
Our infrastructure has an important opportunity to contribute to greenhouse
gas targets
The Building and Construction Sector Plan (under the ERP) details actions and initiatives to contribute to the emissions reduction targets. One of these actions (Action 12.1.1) is to progress regulatory change to reduce embodied emissions of new buildings. Another action (Action 12.2.2) is to use government purchasing power to drive market change, including an initiative to support the implementation of a procurement guide to reducing carbon emissions in buildings and construction.
The government consulted on the Whole-of-Life Embodied Carbon Reduction Framework in 2020 which outlines how we can achieve reductions of carbon emissions from the Building and Construction Sector. While embodied carbon assessments are currently voluntary, this methodology is intended for use by anyone involved in the design, construction, operation and management of buildings in Aotearoa New Zealand. This guideline provides further detail specific to water to support management of this aspect of carbon reduction, to support the urgent need for change.
Embodied emissions will be increasingly important as the grid decarbonises
As operational emissions reduce over time due to increased efficiency and decreased emissions in our energy grid, embodied emissions can be expected to contribute a greater proportion of the total emissions over the life of an asset, as shown in Figure 1. Embodied emissions must therefore be addressed, if we are to meet our national Climate Change commitments and play our part in crucial global efforts to limit climate change.
(Source:
Figure 1: Expected contributions of operational and embodied emissions over time.
Ministry for Business, Innovation and Employment’s Whole-of-Life Embodied Carbon Emissions Reduction Framework)
4. How does embodied carbon align with broader societal goals?
This guide focuses only on greenhouse gases, which is one parameter of many which should be considered as part of decision-making. Other aspects of the sustainability transition are outlined in Figure 2. To avoid conflicting metrics, siloed thinking or knowledge system dominance we must aim to use embodied carbon calculations in support of wider social considerations and aspirations. It is recommended to always state the limits of your assessments when reporting to prevent “carbon tunnel vision”. For example you might report the embodied emissions associated with new infrastructure alongside an acknowledgement that these emissions are required to provide positive health outcomes through delivering clean water. We must deliver the wider project outcomes required (e.g. to treat wastewater and prevent degradation of water quality), while minimising the carbon emissions. Refer to Figure 2 for broader outcomes to consider alongside embodied carbon emissions.
Figure 2: Carbon tunnel vision (Source: SEI, Jan Konietzko)
Recognising the importance of indigenous perspectives
It can be expected that climate and embodied carbon discussions consider indigenous themes including decolonisation, political and ideological power sharing and the struggles for justice of indigenous peoples. Sustainability experts the world over acknowledge this is part of what is required and therefore can be an important consideration for reduction plans. In planning their broader emissions reduction journey, teams should consider building strong relationships with Māori as traditional custodians of our lands. Upskilling and building of awareness and understanding of mātauranga and Te Ao Māori in team members is an important part of our education alongside topics in courses about carbon accounting, engineering, science or design.
Alignment of embodied carbon with Te Ao Māori concepts
Products with higher embodied carbon may be thought to represent a higher burden on Ranginui, Papatūānukuand all atua associated with the health and wellbeing of te taiao. Mauri is a measure of health and vitality, and it can be considered that high embodied carbon items are likely to lower the mauri of areas the resources are being taken from/manufactured in due to the ‘environmental cost’ the items represent in the carbon footprint.
One major difference with embodied carbon and mauri, is that mauri can be seen, smelt, felt, tasted and heard. Embodied carbon measurement does not have a sensory base as it is drawn from calculations of gases that is converted to carbon dioxide equivalent. It can therefore be harder for people to visualise or conceptualise embodied carbon in comparison to mauri.
Upholding Te Tiriti o Waitangi
Taking an approach that upholds Te Tiriti responsibilities requires acknowledging that embodied carbon is only one aspect to be considered for ensuring wellbeing and future proofing of water sector activities.
Local context is also very important. Areas of significance may need to be cared for in specific ways rather than have generic embodied carbon goals applied. For example in completing carbon reduction projects alignment with Te Mana o te Wai, reuse and recyclability information for zero waste, protecting historical sites or habitats from disruption should be included in project considerations. Low embodied carbon solutions may reduce the general impact from a carbon perspective, however if infrastructure is in the wrong place, or with design insensitive to local context, the mauri may be lowered regardless.
Informing our approach using mātauranga Māori
Embodied carbon and climate change is framed in a western knowledge cultural context. Understanding this is important so that the measuring of embodied carbon does not inadvertently lock out Māori knowledge systems or worldviews.
Western scientific understandings of climate change describing discrete processes based on emissions, do not capture the underlying or totality of the problems or possible solutions. Indigenous peoples have concepts and values that encompass climate and climate change in relational and reciprocal ways.
The paper Climate change and mātauranga Māori – making sense of a western environmental construct (Taiapa. K et al, 2024) demonstrates how mātauranga Māori is a dynamic collective knowledge system. Māori-led initiatives in te taiao are becoming sought after yet remain undervalued and require considerable work of Māori to maintain the practices within mātauranga Māori in working with these western scientific concepts. This knowledge is an important resource to slow the drivers of climate change, promoting paradigmatic powershifts and resisting the system and structures that maintain the current climate trajectory.
There are several existing mātauranga Māori frameworks for monitoring water related projects and impacts, that embodied carbon measurements can draw on, and in turn add information to support this existing work. These include:
• MauriOmeter | Tapuika Iwi Authority – https://www.tapuika.iwi.nz/mauriometer/
• Mauri compass – https://www.mauricompass.com/
• COMAR – Cultural Opportunity Mapping, Assessments and Responses – https://www.comar.co.nz/
• Te Takarangi – https://www.projectmoonshot.city/our-origins
5. What is embodied carbon?
5.1 Embodied Carbon – Capital Carbon –Operational Carbon: What’s the difference?
Capital carbon refers to the emissions associated with the creation of assets or capital works.
Operational carbon focuses on activities of an organisation, to produce the product or service, rather than the product itself e.g. energy, heat, lighting or the use phase.
Embodied carbon is the emissions from the products, transport and maintenance that form the building or infrastructure across the assets life cycle. This is commonly called the carbon footprint of a project.
Once emissions have been identified, the emissions are typically grouped into two types of scopes: direct and indirect emissions
Direct emissions are those controlled by the company (scope 1), while indirect emissions stem from the generation of purchased electricity (scope 2) or from activities in the value chain (scope 3).
Within the supply chain, upstream operational emissions become embodied emissions to organisations downstream. For example. electricity used to create a product upstream supports processing and use of sold products downstream, refer to figure 3 below.
Figure 3: GHG Protocol Emission Scopes (World Resource Institute, 2011)
In the case of a council or government organisation as an example, their scope 1 direct emissions would be the use of their vehicle fleet and recording their fuel and their operational carbon would be their indirect emission from the use of energy scope 2. Should the council build an infrastructure project, they subcontract the works to others and becomes a scope 3 indirect emissions. As a contractor builds the infrastructure project, their operational emissions (fuel) to complete the project adds to the capital (or embodied) carbon footprint of the asset/infrastructure.
It is important to consider a whole-of-life perspective in embodied carbon decision-making. Practitioners using the whole-of-life perspective can identify which stage they are at and tailor their carbon management strategies to minimise their environmental impact, refer section 5.4 whole-of-life embodied carbon.
As shown in Figure 4 below, designs with their carbon emissions/footprint, can be plotted over the asset’s lifecycle, including its replacement and maintenance. Emissions at peak points can be identified and potentially reduced, refer section 7.
Figure 4: Operational and embodied carbon emissions over the project lifecycle.
5.2 The Greenhouse Gases
All greenhouse gas emissions are reported on a carbon dioxide equivalent basis (CO2-e). Table 1 gives an example of the GWPs global warming potential of different gases (with the average warming potential over 100 years). Emissions from other more harmful greenhouse gases such as nitrous oxide, methane, perfluorinated compounds or other F gases such as sulphur hexafluoride are converted to a CO2-e basis using the Global Warming Potential (GWP).
Care should be taken when gases such as Perfluorinated compounds such as sulphur hexafluoride (used in high voltage equipment) and fluorinated ethers (such as R-12 used in refrigerants) are used as the GWP potential of these gases is in the tens of thousands of years.
Table 1: Global Warming Potential of GHG’s (Intergovernmental Panel for Climate Change (IPCC) Fifth Assessment Report (AR6)) based on a 100 year period.
5.3 Embodied carbon production of common water industry materials
Greenhouse gases are produced in the production of all materials. The amount of material produced associated with one tonne of carbon dioxide equivalent gases for common water industry materials is shown in Figure 5. By way of reference, the production of these materials is equivalent to approximaetly the daily travel of 200 cars1
Values provided in the figures are order of magnitude approximations only and are likely to decrease over time. Some are based on individual products. Additionally, timber materials have a stored value of carbon not captured in the figure.
Sources of emissions data that provide carbon dioxide equivalence values for products and materials are available from;
• New Zealand Green Building Council (NZGBC) NZGBC Embodied Carbon Methodology available from https://nzgbc.org.nz/embodied-carbon
• EPD Australasia – https://epd-australasia.com/epd-search/
• BRANZ – https://www.branz.co.nz/environment-zero-carbon-research/framework/
• Ministry for the Environment –https://environment.govt.nz/publications/measuring-emissions-a-guide-for-organisations-2024-detailed-guide/
• Infrastructure Sustainability Council (subscription required) https://www.iscouncil.org/isupply/
1 Based on vehicle emissions prediction mode; 7.0 – Waka Kotahi 2024 and Ministry of Transport Fleet Data 2022
Embodied carbon values for figures were sourced from the EPD Australia, based on individual products as follows, 3: Superlit GRP 2020, 4: Humes 2023, 5: RXP 2022, 6: Iplex 2021.
Sources of embodied carbon values used in the figure are sourced from databases listed in section 5.3.
These are order of magnitude approximations based on the 2024 year only and are likely to decrease over time.
Values will vary based on manufacturing techniques, pressure ratings and strengths. Timber has a stored value of carbon not captured in these figures.
Figure 5: 1 tonne of CO2-e created in the production of water industry materials.
5.4 Categorisation of Greenhouse Gas Emissions
The two most common standards for
Greenhouse Gas Reporting are:
1. The Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard (The GHG Protocol). It is available here: https://ghgprotocol.org/
2. ISO 14064-1:2018 Greenhouse gases – Part 1. Specification with guidance at the organisation level for quantification and reporting of greenhouse gas emissions and removals. It is available here: https://www.iso.org/standard/66453.html
Each of these documents provides guidance on ‘scope’ and boundary setting for an organisation and should be used when establishing carbon measurement as well as during verification.
Under the GHG Protocol, greenhouse gas emissions reporting is considered in three separates scopes, whereas ISO 140641:2018 breaks these scopes down into various ‘categories’ to further distinguish emissions sources. Table 2 demonstrates how these ‘scopes’ and ‘categories’ relate to one another.
Table 2: Scope and Category comparison
Scope 1:
Direct GHG emissions from sources owned or controlled by the company (i.e. within the organisational boundary). For example, emissions from combustion of fuel in vehicles owned or controlled by the organisation.
Scope 2:
Indirect GHG emissions from the generation of purchased energy (in the form of electricity, heat or steam) that the organisation uses.
Scope 3:
Other indirect GHG emissions occurring because of the activities of the organisation but generated from sources that it does not own or control.
Category 1:
Direct GHG emissions and removals that occur from GHG sources or sinks inside the organisational boundaries and that are owned or controlled by the organisation.
Category 2:
Indirect GHG emissions from imported energy due to fuel combustion associated with production of final energy and utilities. It excludes all upstream emissions associated with the activity.
Category 3:
Indirect GHG emissions from transportation (mostly fuel burnt in transport equipment, but if relevant also includes upstream emissions from fuel generation, transportation and distribution or construction of the transport equipment).
Category 4:
Indirect GHG emissions from products used by an organisation including extraction and transport of raw materials, and manufacturing.
Category 5:
Indirect GHG emissions associated with the use of products from the organisation (services and products sold by the organisation).
Category 6:
Indirect GHG emissions from other sources. The purpose of this category is to capture any organisation specific emission or removal that cannot be reported under another category.
When referring to the embodied carbon emissions of a project, these are often the Scope 3 (Category 3 – 6) emissions. This includes emissions associated with the:
• Upstream extraction, production, transport, and manufacturing of a product;
• Construction of an asset using these products/materials;
• Upkeep and maintenance of the asset once built; and
• Any downstream end of life emissions for the product.
This brings us to considering Whole-of-Life Embodied Carbon.
5.5 Whole-of-Life Embodied Carbon
A Life Cycle Assessment (LCA) is typically used to calculate embodied carbon emissions of an infrastructure project. These are typically done by an LCA specialist, or by designers using software and tools to navigate the complexity and requirements in standards. LCA is a growing capability within the water sector.
The principles and framework for life cycle assessment (LCA) and life cycle inventory (LCI) studies are described in ISO 14040:2006 and the requirements themselves are set out in ISO 14044:2006. Of relevance to the water sector, ISO 21930:2017 establishes a core set of requirements to be considered as product category rules (PCR) to develop an Environmental Product Declaration (EPD) for any construction product or service. Using EPDs can accurately inform decision-makers of the total embodied carbon input associated with a component of a project. However, it must be noted that social and economic impacts are not considered in these standards.
6: Module framework for life cycle assessment of an infrastructure project (BS EN 15978) (Source: MBIE, 2020)
Figure
The scope of a Life Cycle Assessment may not include all stages, the following terms are frequently used to describe the extent of an LCA, as shown in Table 3.
The standards for LCA in construction define life cycle stages for the purposes of embodied carbon according to a module framework (refer BS EN 15978), and these are shown in Figure 4. Table 3 describes, with examples, what this may look like for a water infrastructure project.
Table 3: Stages and terms used in product life cycle assessments
Description
Cradle to Gate
Cradle to Practical Completion
Cradle to Grave
Cradle to Cradle
A1-A3
A1-A5
A1-A5 & B1-B5 & C1-C4
Product Stage
Product & Construction Stage
Product, Construction, Use & End of Life Stage
A1-A5 & B1-B5 & C1-C4 & D All Stages
Stage Module Example
Product Stage (A1-A3)
Note: EPDs inform users of A1-A3 product stage emissions
Construction Stage (A4-A5)
Material extraction (A1) Extraction of aggregates and cement ingredients, raw materials for plastics, fibreglass, metal ore etc.
Transport to manufacturer (A2)
Use Stage (B1-B5)
Trucking / shipping the raw materials to the manufacturing facility.
Manufacturing (A3) Facility emissions associated with concrete manufacture and casting of product, manufacturing of resins and moulding products, metal / aluminium crafting, electrical component fabrication, steel pipe welding etc.
Transport to site (A4) Transportation of materials (pipes, manholes, culverts, structures), temporary works, people and plant (excavators, rollers, trucks) to the project site.
Construction (A5) Placing the pipe in the ground with a diesel excavator via open cut excavation or using trenchless technologies such as Horizontal Directional Drilling, Microtunnelling or Pipe Jacking. Installation and commissioning of manufactured system.
Use phase (B1) Concrete carbonation but excluding operational carbon.
Maintenance (B2) CCTV checks of pipe, hydro jetting or routine clearing of debris or build-up from a pipe or culvert. Greasing motors and bearings, fan & pump checks (airflow, pressure etc). Instrument calibrations.
Repair (B3) Repairing of cracks in pipelines, or leaking equipment. Flood recovery.
Refurbishment (B4) Provision of a pump station with new equipment or exterior decorations, adaptions required for changes in flow / climate. Pipe rehabilitation or relining of an existing pipe via slip lining, CIPP, fold and form, spiral wound lining.
Replacement (B5) Replacing a corroded pump with a new pump. Wearing part replacement (e.g. fan belt). Replacement of corroded parts or aged instrumentation / electrics. Replacement of pipes using pipe reaming or pipe bursting.
Operational Carbon (B6-B7)
Operational Energy (B6) and Operational Water (B7).
Table 4: Embodied Carbon Modules with Examples (Excluding Operational Carbon)
Stage Module Example
End of Life Stage (C1-C4)
Deconstruction (C1) Deconstruction of a former stormwater system, digging pipes, catchpits or manholes out of the ground.
Transport to end of life facilities (C2)
Benefits and Loads Stage (D)
Transporting deconstruction waste to local fill or recycling site for disposal.
Waste processing (C3) Processing of materials prior to disposal (separation of metals from concrete).
Disposal (C4) Placement and compaction of materials into the fill, and any long-term associated emissions with fill.
Benefits beyond the system boundary (D): These are to be reported separately to modules A-C
Any re-use, recovery or recycling of materials.
6. When do we apply this?
6.1 Scoping – Where to start
The scale and complexity of measuring embodied carbon can make determining where to start a challenging question. This can be further complicated by the fact that the starting point will depend on the motivation and goals of the project and the knowledge base of the team, which in turn define the project scale and scope. Therefore, the first step in establishing where to apply embodied carbon measurements is by defining the goal and scope of the project. The GHG Protocol Accounting and Reporting Standard, chapter 2 and 3 provide more information on setting goals and organisational and operational boundaries.
The flow chart below gives a simplified guide for moving through the stages from Goal setting to data capture.
Define Goals, Scope and Assumptions
Set Study Boundary
Work Breakdown Structure
Identify Sources and Quantify
Select Calculation Approach
Collect data and choose emission factors
Calculate GHG Emissions
Roll Up data / Reporting
The goals, scope and assumptions must be defined especially if the project is complex. Having a goal will set clearly defined aims and objectives.
The study boundary discussed here is in context of life cycle assessment and the study in product stage A1-A3 (cradle to gate), construction stage A4-A5 (cradle to practical completion).
Knowing and understanding the construction methodology and creating a work breakdown structure would greatly assist in identifying the potential sources of emissions – plant machinery, labour, and materials.
Once the emission sources have been identified, the activities need to be quantified and allocated to an emission type.
The calculation approach is used and the direct measurement approach.
Data from NZ databases or local EPD emission factors will be used if possible.
Emission sources and allocate to emission categories and calculate.
All activities are quantified and calculated and referred to as the carbon footprint and is reported and given to the required stakeholder.
Figure 7: Structured Steps for assessing embodied carbon (K. Manalo (2023)
The table below contains a list of potential motivating factors and questions that can be used to define the goal, scope and level of detail of the project. These are then explored in more detail below.
Table 5: Motivators and questions for scoping embodied carbon project assessments
Potential motivators
Goals of organisation / Stakeholder preferences
CO2
Asset investment decisions
Questions to determine the goal and scope of the project
• What is the focus of your organisation’s sustainability policies?
• Is your organisation focused on global climate change aligned objectives or supporting the needs of local customers objectives?
• What are the stakeholder benefits or positive impacts associated?
• What are different stakeholders of your organisation requesting information about?
• Are new assets or equipment being proposed or does an existing asset need renewal?
• Is there an opportunity to consider an alternative development pathway based on the measurements?
End use of the measurements / Emissions reporting
Alignment with supply chain and market signals / Customer requests & people
• Is the embodied carbon tied to a particular project?
• Is the end use of the embodied carbon measurements to educate change in an existing project or a future project?
• Are the measurements going to be reported externally or used as a base case internally?
• Do your supply chain partners have embodied carbon measurements and resources you can draw on?
• Is your supply chain incentivised or required to provide embodied carbon information?
• Do your customers have a level of detail and scope that is required for their measurements?
• Are customers pulling for this data or is this a proactive project?
• Are weighting factors included in tenders?
Goals of the organisation
CO2
The sustainability goals of your organisation can quickly determine the level of detail required in measuring embodied carbon. For example, if your organisation has mandated the use of the Infrastructure Sustainability Council (ISC) Rating Scheme, Green Star Buildings, PAS 2080 accreditation, or a similar scheme, then the scope and level of detail are predetermined. If, however, your organisation is just starting out and is looking to get a general measure of embodied carbon, then the scope and level of detail can be used in developing an understanding of the process in the first instance and improved / extended later as required.
Asset Investment Decisions
The largest opportunity in reducing embodied carbon is often in the scale of proposed infrastructure. The planning and investment decision phases of projects are therefore critical for considering options relating to “Do Nothing” by reusing or repurposing existing assets or alternative approaches, or “Do Less” through the introduction of advanced process technology for example.
Limiting the scale of new investment may also require behavioural or consumer change. The adoption of low-flow consumer products to reduce water use can extend the life of existing assets and public education programmes have a place in our strategies to reduce embodied carbon. These considerations cannot be applied when a capital delivery project is live, so must be considered at a higher level in your organisation.
Aligning embodied carbon considerations with asset life cycle ensures legacy assets are considered as part of a structured approach.
End use of the Embodied Carbon Measurements / Emissions reporting
The end use of embodied carbon measurements will have an impact on the scope and level of detail required. If the embodied carbon measurements are tied to a particular project, distinguish whether the end use of the measurements is to create changes within the existing project, or to educate to inform future work:
• If the change is intended for the existing project, then the starting point and scope can be limited to the current state of the project and the level of detail that is available in a timely manner.
• If the change is intended for a future project, expand the scope and provide more time to gather a higher level of detail to increase the level of impact and motivate more in-depth measurements.
If reporting externally, it can be useful to align with a recognised embodied carbon reporting system, or scheme, so that parties receiving the data will be able to interpret it easily. This may require a higher initial level of detail. If the embodied carbon measurements are only for internal purposes, then the measurements can be more limited in scope to areas of interest and the level of detail can be refined over time.
Greenwashing and Greenhushing
A common concern at the outset of embodied carbon measurements is a fear of being accused of greenwashing if the scope and level of detail of measurements are not perfect. This can, in turn, lead to avoiding communication, called greenhushing
Measuring embodied carbon is inherently difficult. To combat greenwashing and avoid greenhushing aim for a high degree of transparency, including any retrospective updates for increased accuracy. Whatever scope and level of detail you decide on, it is important to include that information and the decision-making process as part of your reporting so that this can be factored into how the information is used.
Alignment with supply chain and market signals / Customer Requests and People
Your supply chain can have a significant impact on the availability of data and how it will be used. Most organisation’s embodied carbon footprints (excluding primary resource extraction) are dominated by Scope 3 / Category 3-6 supply chain emissions. Investigate whether your suppliers are measuring their carbon emissions and, if appropriate, align your scope and level of detail with their reporting. If your organisation has purchasing power in your industry, consider whether your supply chain can be motivated to generate embodied carbon data and demonstrate reductions through incentives and contractual requirements. End users of your emissions reporting (customers, designers or investors etc) are likely to have data gathering requirements to align with for maximum benefit. Developing these relationships during the calculation process can also lead to innovation opportunities, for example to support reuse, recycling and improved design or processes.
People and collaboration are a vital aspect to the process of reducing embodied carbon. The assessment of numbers and calculations must come alongside the forging of collaborative networks. Networks of motivated people can have a more positive impact than carbon calculations alone. Seek to use the process of understanding embodied carbon as an opportunity for new types of conversations, with different parts of your supply chain, customers, end users or internal team. Support behaviour change by being open for collaboration in new ways and places. Reach out to initiate new relationships and suggest new projects and support other peoples’ initiatives. Contribute to behaviour change in your organisation with upskilling sessions, training, research and sharing reflections. Support messaging about the importance of being on the journey and recognise that innovations and improvement ideas happen at all levels of our organisations.
6.2 Resources for starting out
The same steps outlined to establish the goals and scope of embodied carbon measurements can also help to establish resources for starting your measurements. These resources can include:
• Supply partners that have performed similar measurements;
• Sustainability schemes aligned with your organisation (e.g. IS Rating Scheme and Green Star Buildings, PAS 2080);
• Professionals in your industry whose organisations have performed the same measurements; and
• Case studies from other industries.
To this end the bibliography references resources that may be useful in your journey.
The next section outlines how you might go about undertaking a carbon assessment depending on the scope determined above.
Case Study – Tauranga City Council’s Embodied Emissions Baselining
The keys to success for Tauranga City Council’s (TCC’s) embodied carbon baselining was taking the time at the start of the project to define the scope, decide on the processes and engage key stakeholders. TCC reached out to their supply chain expertise for support, and worked with carbon assessment experts, Mott MacDonald, to develop a method to select key projects that would meet the scope and goals of the baselining work. This involved holding initial internal workshops to get input on the scope and data needed for the project. These workshops gave internal stakeholders an opportunity to be involved in the journey and to align with other internal initiatives for ease of data collection. From these workshops, TCC ended up selecting 40 representative projects from the Long-Term Plan (LTP) to use for the baselining and limiting the scope of embodied carbon emissions to ‘cradle to practical completion’ (modules A1-A5).
Following the development of its baseline, TCC has commissioned a project to understand how to implement Carbon Management into all stages of capital works from initiation at LTP to construction and commissioning.
7. How do we apply this?
7.1 Conducting carbon assessments: How to start
How you assess carbon in your project depends on the delivery stage. Early project stages will involve high-level assessments that are in line with the detail available and later stages will allow more granular assessments (Figure 8). The impact that the client, designer and contractor can have on reducing carbon emissions also changes throughout the project life cycle.
The biggest opportunity to reduce carbon is in the early stages of a project (Figure 9). The first and most decisive steps for carbon reduction is to avoid the need for constructing infrastructure in the first place. This is the Avoid phase where options need to be considered that still meet the need for the project but can be done so in a different, sometimes innovative approach, that requires less intensive infrastructure.
A good mindset to use at this phase is the use of the 5R’s (Refurbish, Reduce, Replace, Reuse, Require).
• Refurbishing: Instead of demolishing and creating a new pump station or a water/wastewater treatment plant, if there is an existing building or infrastructure can it be refurbished?
• Reuse: Can the existing building or infrastructure be re-used or deconstructed?
• Replace: Instead of demolishing whole portions of the facility, are there modules of the building or infrastructure which can be replaced?
• Reduce: Instead of designing a large facility, can the facility function with a small construction footprint (reduction of materials)?
• Require: Consider using new materials which could have lower carbon value than the traditional materials used.
As we move through the design phases of a project, the carbon reduction opportunities move to a Switch approach. The focus in Switch is on switching construction methodologies and material selection for lower carbon alternatives.
The Improve phase, then provides the chance for further reductions, but these are likely to be at a smaller size and scale, and in the construction/operation phase. At this stage it is still possible to Improve the carbon project outcomes, and the focus should be on efficiency.
Figure 8: Carbon assessment influence and accuracy over the stages of infrastructure delivery (Source: PAS 2080: 2023)
It should be noted that the commentary below is a guide and categories are generalisations that can be flexible. Avoid principles are not only contained in the strategy and concept phases but are primarily done at the start of a project, just as Switch principles could be considered earlier or later in the carbon reduction process depending on the project and the designer.
Examples applicable to the water sector are outlined in Appendix I: Example Carbon minimisation considerations in water assets.
7.2 Avoid – Strategy to Concept
At the early stages in the project’s life cycle there is the greatest opportunity to reduce carbon. Building nothing is the optimum way of not producing carbon but may be a challenging solution to unlock. Success with Build Nothing solutions may require significant time to explore alternative options and strong organisational conviction to zero carbon solutions. This approach to infrastructure development is always worth exploring as it may assist in developing creative alternatives to business as usual options.
Strategy Phase
At the strategy stage there is the possibility of challenging the need for high carbon infrastructure solutions by assessing whether there are fundamentally different, and lower carbon ways of meeting the defined goals.
Key design assumptions can be challenged, such as:
• Purpose of the infrastructure – are there other means to achieve this?
• What alternatives have been considered?
Examples and case studies for Avoid:
• Treatment Process optimisation examples;
• Daylighting of streams and removing piped networks – Healthy Waters;
• Change consumer behaviour – LowCO Home;
• Desalinisation plants as infrastructure alternatives.
In Avoid, strategies such as consumers reducing water use can eliminate the need for infrastructure upgrades and the associated embedded emissions. The Fletcher LowCO home has been a recent example of this long-term strategic approach. By minimising the water that is used in our homes, we avoid the need to develop future infrastructure to service them.
Figure 9: Carbon management in buildings and infrastructure (Source: PAS 2080: 2023)
Case Study: Awakeri Stormwater Improvement
The Awakeri Wetlands form part of a greater stormwater servicing scheme for the Takanini south-east area designed to enable the residential development of the area. The scheme enables the comprehensive development of 162 hectares to provide housing for a community of approximately 15,000 people.
The Awakeri Wetlands consist of 2.3 km of open waterway and will convey the 1% AEP flow from the catchment (including allowance for climate change) of 40m3/s. A conventional design would involve a pipe with a dry overland flow path. Post construction, Mott MacDonald evaluated the carbon footprint of the wetlands compared to the conventional approach. The wetland option had a significantly reduced embodied infrastructure carbon footprint. For the conventional design carbon was estimated at 7,400 tCO2e while the open wetlands carbon was estimated at 1,900 tCO2-e, a saving of >70%.
Other benefits of the open wetland system included:
• Provision of an ecological corridor and connections (both terrestrial and aquatic);
• Open space with significant amenity value including pedestrian and cycle linkages;
• Integration of cultural values and history;
• Restoration of the repo (swamp);
• Cultural (rongoā and raranga) planting;
• Community space and opportunities for public and mana whenua art.
Figure 11: Awakeri – Option 2: Wetlands Layout
Figure 10: Awakeri – Option 1: Conventional Pipeline
A carbon assessment at Strategy stage of strategic options will be high level and with an accuracy relative to the project detail available. During this phase the goal of the carbon assessment is not to be 100% accurate but rather to assess options and understand hotspots. When comparing strategic options carbon assessments can be done by:
• Use a Carbon:Cost ratio (if cost is known);
• Benchmarking: Compare the carbon associated with similar projects (if size is known);
• Modelling: Top-down or bottom-up.
A carbon assessment at the end of the strategic review will be considered the baseline for the project. This baseline is a starting point which helps organisations to identify carbon hotspots and prioritise carbon reduction efforts. It also enables carbon reduction targets to be set, and progress to be tracked at both project and programme levels.
Outcomes of Strategy phase are:
• Preferred strategic option to take through to concept design;
• Carbon hotspot assessment;
• Carbon reduction targets based on hotspot assessment.
Case Study: Fletcher Living and Watercare LowCo Home
Fletcher Living took up a challenge in 2021 to pilot the design and build of low carbon homes. The aim was to minimise the carbon emissions associated with the build and operation, from the materials used through to its energy and water use over a 90-year lifetime.
The first Low Carbon LowCO homes are a three-bedroom detached home and three-unit terraced home block built in 2023 at the Waiata Shores development in Auckland. In addition to its carbon credentials, which achieved a seven-fold reduction in carbon emissions compared to a standard home, the pilot has driven domestic-scale water efficiency to meet MBIE’s 2035 potable water use target of 75 litres per person per day. That’s well below the Auckland average of 160 litres per person per day, and with an appropriate emissions factor of 36g/m3 water supply and 50g/m3 for wastewater (Ministry for the Environment, 2023) has a carbon reduction benefit as well. Through a collaborative partnership with Watercare, the design team found new ways to save water – some innovative, some breaking entirely new ground.
• A New Zealand-first install of a Hydraloop greywater recycling system treats bath and shower water and lightly contaminated grey water and recycles it to flush toilets, supply a selected washing machine rinse cycle and to irrigate the vegetable garden.
• On-site water treatment of rainwater involves UV and carbon filters, making recycled water safe for all household consumption purposes.
• A connected array of water storage pods fit under the suspended floor of the house (8,250L) and within the insulated floor slab of the terrace homes (4,500L each).
• Hard and soft landscaping was made more water friendly. Run off was minimised by reducing impermeable surfaces by 75% and creating a meadow.
• Garden hose connections are supplied by harvested greywater or rainwater and drought hardy plants were selected.
• A digital thermostatic mixer is installed in the showers, reducing hot water wastage and water heating costs.
Using demand-side measures to avoid infrastructure development and the resulting embodied carbon is both a cost and carbon-efficient way of meeting future demand.
Further information is available online at: https://www.fletcherliving.co.nz/about-us/sustainability/lowco/
Concept Phase
The Concept Design Phase generally includes the delivery of an options assessment and concept design for cost estimating purposes. This is where carbon optioneering should be undertaken, still with an ‘Avoid’ mindset. Focus should be on the carbon hotspots identified in the Strategy phase.
Key questions to ask are:
• What are the alternatives within the chosen strategic design?
• Is there new technology or processes available that might change the fundamentals of the design?
• What has been done elsewhere (internal or external) for low carbon designs?
• Can we defer the carbon to a later delivery stage?
A carbon assessment during the concept phase will enable more modelling than at the strategic phase due to more details being available. Modelling can use a ‘top-down’ approach or a ‘bottom-up’ approach (as outlined in Figure 7) or a combination of both approaches to assess carbon. Ideally, after the concept phase, there should be an identifiable reduction in the carbon associated with the design.
Outcomes of the Concept Phase:
• Comparison carbon emissions to the baseline created in the Strategy phase;
• Check on progress to reduction targets outlined in Strategy phase.
Case Study: Brick Barrel Wastewater Options
Christchurch City Council (CCC) engaged AECOM to assess the recommended path forward to either renew or rehabilitate approximately 1.5 km of egg-shaped brick barrel pipelines constructed in 1880. These are major wastewater trunk mains servicing the city, which experience significant inflow and infiltration causing groundwater to wash fines out of the carriageway leading to road subsidence.
An optioneering assessment was delivered, including the development of a decision-making framework developed alongside Council, which included consideration of embodied greenhouse gas emissions estimates. From the eight initial options, three were determined to be viable and were compared:
• Relay via trenching;
• Slip-lining using segmental egg-shaped glass reinforced pipe (GRP);
• Cured-in-place pipe liners (CIPP).
A multi-criteria assessment (MCA) was carried out, assessing technical outcomes alongside environmental, social and governance (ESG) impacts including existing trees, community impacts, and embodied carbon.
Using the 3 Waters Emissions Estimations Tool (3WEET), which AECOM developed for CCC, carbon assessments of the shortlisted options supported Council’s decision-making through the MCA. This comprised estimating emissions for the material manufacture, transport to site, and installation (A1 – A5) including dewatering, overpumping, sheet piling, soft-ground trench and manhole foundations, and other bespoke items required for the trenchless install methods.
Undertaking a carbon assessment at this stage informed decision-making to account for the cost and carbon estimates over the asset design life alongside the technical performance. Ultimately the relay option was selected to be taken forward as, in this instance, comparable embodied carbon footprint over a 100-year span was lower, alongside provision of opportunities for asset improvement.
7.3 Switch – Definition and Detailed Design Phase
During the definition and detailed design phase many of the key design parameters have been set. Potentially, a high-level optioneering study relating to carbon has already been completed during the concept phase and now it is time to consider ‘Switch’ carbon questions. During the Switch Phase there are still large carbon reductions to be made. Key elements during the switch phase are construction methodology and material selection.
This phase can significantly benefit from the inclusion of wider project partners using Early Contractor Involvement (ECI) processes to include contractors who understand the possible construction techniques. Equally, suppliers should be considered whose products, technology or innovations, may unlock significant carbon savings. Identifying these opportunities early through collaboration can set a project up for success across a wide number of areas, such as cost, programme and reduced community disruption as well as carbon reduction.
Project specification
Initial Switch considerations with the most impact often focus on construction methodology. Switch, in this case, could mean:
• What sort of foundation piles are being specified, e.g. steel screw-piles vs reinforced concrete;
• What sort of civil earthworks are being considered, e.g. cut and fill vs mudcrete in-situ modification;
• What sort of construction methodology is being specified, e.g. for a pipeline – open cut trenched or trenchless;
• Specification considerations, e.g. appropriately minimise concrete strength / cement content specifications.
Case Study: Healthy Waters Greville Road Stormwater Culvert Upgrade
When Auckland Council’s Healthy Waters Department was reviewing the options for embodied carbon reductions for its Greville Road Stormwater Culvert Upgrade, it engaged collaboratively with the contractor (McConnell Dowell) and pipe supplier (Hynds Pipe Systems) through a joint workshop.
Hynds Pipe Systems was able to present variations in pipe designs and its HyndsLC range of low carbon pipes, with the relevant embodied carbon reductions, demonstrated the impact that joint profile changes would have on jacking forces. McConnell Dowell was able to give construction requirements of the jacking pipe for installation purposes and procurement timeline.
By undertaking this process, the team was able to include the lowest carbon option that met the project requirements for material strength, timeframes, and costs under the contract and resulted in 60 tCO2e savings through pipe selection alone.
Photo credit: Hynds, McConnell Dowell and Healthy Waters
Material selection
At the detailed design stage most key design decisions have been made but there is the potential to examine and define the material choices that have been specified. Material selection should consider both alternative materials (e.g. plastic vs steel) and low carbon alternatives (20MPa concrete vs low carbon 20MPa concrete) or material that incorporates recycled elements.
For most water projects in Aotearoa New Zealand, common embodied carbon material hotspots will be:
• Concrete;
• Steel;
• Aggregate (and other earthwork fill material);
• Aluminium; and
• Plastics.
All these materials have low carbon alternatives, either as a straight swap (for example 20MPa concrete for low carbon 20MPa concrete) or consideration can be given to alternative materials that can do a similar job, such as glass reinforced plastic pipe instead of concrete reinforced pipe. To assess potential carbon savings, and determine how this might relate to cost, the most accurate carbon emission factors available should be used. Sources for obtaining emission factors are provided in section 5.3.
Specifications can be used to introduce requirements for low carbon options to be considered. For concrete the following approaches can be taken:
• Engage with concrete pipe suppliers to find out about their options for low-carbon materials. Different suppliers will have different tools to achieve the same outcome in terms of embodied carbon (e.g. one using less carbon-intensive cement versus another relying on higher reactivity of cement and / or more supplementary cementitious materials, both achieving the same goal in emissions reduction while maintaining concrete performance).
• Specify a target reduction percentage of embodied emissions against a baseline (like the numbers published by the Infrastructure Sustainability Council (ISC) in 2020) or an absolute embodied emissions target per cubic metre of concrete; however, be aware that concrete pipes are hybrid products of various materials (e.g. steel & concrete) and while pipe strength classes are the same across different suppliers, they may use different concrete compressive strength, wall thicknesses, reinforcement design, etc. to achieve the desired pipe performance; early supplier consultation is key in achieving all targeted project outcomes.
• Require the agreement of the concrete mix design with sufficient time to maximise opportunities across the project.
Minimising the use of virgin materials where possible can also minimise emissions as well as driving waste reduction. Examples of where recycled materials can commonly be incorporated into projects include:
• Use of recycled crushed concrete in roading (e.g. Waka Kotahi, AT Specifications);
• Increase supplementary cementitious materials, slag or pozzolans in concrete.
It is important to consider how changes to the nature of the material effect other factors. For example, high quantities of supplementary cementitious materials (SCMs) in concrete may reduce embodied carbon but may increase strength gain timeframes. These impacts have potential to add costs that are above and beyond the difference in the material cost itself. Whole-of-life considerations are also important. If material changes reduce asset life, this has the potential to negate embodied carbon savings over the life of the product. But usually, acid resistance and durability in general are positively affected through the use of supplementary cementitious materials.
Partnership and engagement with the supply chain is therefore highly recommended. Many suppliers are now moving to incorporate low carbon options and for high volume raw materials there are often regionally-based opportunities. Industry organisations are also driving change which project partners can support by focusing investment in areas identified as providing sector-wide benefits.
Case Study: Concrete NZ Decarbonisation Road
Map to Net Zero
In 2023 Concrete NZ launched the Industry Roadmap to Net Zero. This roadmap sets out a plan for how the concrete industry will decarbonise and play a major role in a sustainable future. It describes an achievable pathway for the NZ concrete industry to reduce direct and electricity-related emissions by 44% from 2020 levels by 2030 and to net-zero concrete by 2050.
Specifying concrete with a lower Global Warming Potential (GWP) compared to a New Zealand concrete baseline, such as that of the Infrastructure Sustainability Council (ISC), is both feasible and recommended today. Given the variations in raw material availability, transport distances, and concrete operations infrastructure, it is always prudent to consult with potential suppliers and discuss the project requirements with them.
The roadmap covers both ready-mixed concrete and concrete products and builds on past and current initiatives. It involves the major parties in the concrete value chain, including researchers, government and other stakeholders. To be successful in continuing to reduce our emissions, further R&D, investment and commitment from all of these parties will be crucial.
The roadmap is available at: https://concretenz.org.nz/page/2050_roadmap
Figure 12: Decarbonisation roadmap of cement and concrete in Aotearoa New Zealand
Hierarchy of Carbon Emissions Factors
In using Emission Factors, Pandey et al. (2011) recommends using region-specific emission factors where possible. Regionspecific emission factors are verified to its operation and geographical context. In essence the use of local suppliers, which are region-specific and verified by a third party (BS EN 15804 compliant), provides the best basis for decision making. Figure 12 below documents a hierarchy of information sources based on their quality and reliability. Relevant sources for accessing carbon emission factors are listed in section 5.3.
Figure 12: BRANZ Emission Factor Quality Scale
7.4 Improve – Construction and Supply Chain Collaboration
The Improve phase requires a mindset that seeks better outcomes than current norms. During construction, a positive team culture and approach to reducing carbon emissions can see important reductions achieved through behaviour change. The use of goal setting and monitoring can provide important motivation to teams, and feedback and celebrating success can see small changes being scaled into larger wins.
Investment in new technology by contractors, and the supply chain, has an important role in our journey to reduce construction emissions. Clients play a part in this through providing insight into their works programmes and procurement pipelines so suppliers and contractors can confidently invest in new technologies. These investments can drive changes at scales that impact many projects across a programme, providing significant benefits over time.
Using local supply options, which reduce transport distances, is an important consideration during procurement. Partnership may be necessary with designers at this stage to unlock local supply and enable specifications that support the use of appropriate local material.
Case Study: Silverstream Bridge
In delivery of Whakawhirinaki: The Silverstream Water Bridge collaboration and Early Contractor Involvement combined with target setting yielded some great results. Whakawhirinaki provides a walking path and water bridge, carrying around 40% of the water for the Wellington region across Te Awa Kairangi, the Hutt River. The project is part of a multi-year programme to ensure that the Wellington region is well equipped to respond in the event of a major earthquake.
In delivering Whakawhirinaki the client, designer and contractors combined efforts to redesign this important pipe-bridge asset with carbon reduction as a focus. Through changing the structure form and key materials the team was able to save an impressive 62% of the original structure’s embodied carbon. The fundamental changes were a shift from concrete to a steel bridge structure. This unlocked a reduction in the piled foundations and the embedded carbon in both the super structure and sub structure
Photo credit: Wellington Water Limited & Mark Tantrum Photography
Examples of ways to reduce construction emissions:
• Reduce transport emissions through use of local suppliers and utilise return loading;
• Using digital tools for fleet, site management optimisation and virtual inspections, for example;
• Integration between construction projects across asset owners i.e. resource sharing through working together;Use of geosynthetics to reduce removing low strength material;Reduce fuel-burning plant machinery;
• Driver efficiency training;
• Intelligent compaction and real-time monitoring;
• Off-site construction / prefabrication;
• Trenchless pipe installation;
• Reducing removal of spoil from site, for example encapsulating contaminated soil;
• Early contractor and supply chain involvement to develop efficient construction methodologies.
7.5 Reporting and Verification
Organisations are increasingly determining their carbon emissions and having these verified for reporting purposes. Some organisations undertake such reporting to demonstrate their sustainability commitments and provide market differentiation and others to identify hot spots for improvements in their activities. Increasingly carbon reporting and verification is being driven by mandatory reporting initiatives, such as The Financial Sector (Climate-related Disclosures and Other Matters) Amendment Act 2021
To date, most emissions reporting has focused on organisations operational emissions. Guidance, emissions and supporting resources for these types of emissions factors are provided by the Ministry for the Environment in, Measuring emissions: A guide for organisations, (Ministry for the Environment, 2023). Further emissions on accounting for water services emissions is provided in Navigating to Net Zero: Aotearoa’s water sector low-carbon journey, (Water New Zealand, 2021) and the Carbon Accounting Guidelines for Wastewater Treatment: CH4 and N2O. Links to these resources are available in the bibliography.
Depending on their carbon maturity some organisations may elect to be carbon zero or be climate positive.
Carbon Zero – Is a certification process where an entity (asset owner / business / company) has made efforts to reduce their carbon emissions as far as possible and have quantified or rolled up their emission. They would then elect to offset their residual emissions by purchasing carbon credits. The balance of having an entity’s overall carbon emissions reduced by carbon offsetting is carbon zero (Total Emission – Offset = Carbon Zero).
Climate Positive – this process is like Carbon Zero but takes it one step further. An entity has achieved carbon zero but elects to go beyond by offsetting more emissions than they produce (essentially being net positive).
Increasingly, organisations are seeking to expand their emissions reporting scope to include capital carbon, and emissions along their supply chain. An asset owner may require their supply chain (designers, constructors, suppliers) to report on their carbon contributions to projects. Table 6 provides examples of how typical products and construction methods used in the water sector align with greenhouse gas reporting protocols.
Reporting carbon emissions may be as easy as quantifying an activity and multiplying its emission factor or quantifying multiple activities and applying its applicable emission factor. This process is typically a bottom-up approach. A step-by-step guide is outlined in the Carbon Footprint Of Open Cut Pipelines (NZ Context) paper provided in the bibliography.
8. What are our Roles and Responsibilities?
Reducing embodied carbon in infrastructure is the collective responsibility of all participants in the water sector. Each stakeholder in the lifecycles process – clients, designers, contractors, and the supply chain – plays a significant role in achieving this goal. Some of the roles and responsibilities for each are outlined here.
Key principle: Collaboration is essential with all involved and in all Project phases.
• Owner
• Set sustainability goals, requirements and budgets for projects.
• Encourage the selection of low-carbon materials and construction methods.
• Consider life-cycle assessments and carbon accounting in decision-making processes.
• Provide incentives for contractors and designers to prioritise carbon reduction and ensure tendered commitments are enacted.
• Establish a contractual framework between participating partners that maximises outcomes.
• Provide opportunities and tools to share low carbon solutions across the supply chain to drive down emissions.
• Designers
• Incorporate sustainable design principles to minimise embodied carbon.
• Optimise material selection and design specifications for reduced carbon footprint.
• Utilise software and tools for carbon analysis and modelling during the design phase.
• Explore unlocking reductions through Early Contractor Involvement and specification changes to include construction techniques and local, low carbon materials.
• Explore innovative design strategies such as modular construction and adaptive reuse to minimise embodied carbon.
• Contractors
• Implement construction practices that minimise waste and energy consumption.
• Collaborate closely with designers and suppliers to ensure adherence to low-carbon specifications.
• Promote the use of recycled and low-carbon materials in construction.
• Invest in training and education for staff on sustainable construction techniques.
• Supply chain
• Provide access to low-carbon materials and products.
• Develop sustainable sourcing practices to reduce carbon emissions associated with material extraction and transportation.
• Invest in research and development of new materials and technologies with lower embodied carbon.
• Collaborate with clients, designers, and contractors to offer sustainable solutions and support carbon reduction initiatives.
• Iwi, hapū and whānau
• As tāngata whenua and mana whenua, iwi, hapū and whānau have intergenerational responsibilities to their whenua, moana, taonga and people.
• Have knowledge of local areas, cultural practices and histories that can assist with ensuring development occurs in appropriate areas and is protective of sites of cultural significance.
• Have, or begin working on, water related strategies, and locally appropriate measures of wellbeing to protect te mana o te wai, reflected in projects.
• Work with intergenerational long-term planning, that provides projects with long-term views.
• Verifiers and independent industry bodies
• Independent verifiers can cross pollinate lessons learnt across projects.
• Assist industry and organisations in celebrating success.
• Hold organisations to account in ensuring a carbon focus through the project’s lifecycle.
• Ensure early-stage processes and commitments are commenced to capture important early-stage wins.
• Funding partners and provider
• Provide important capital for importing new technology.
• Support organisations to invest.
• Support important cultures of entrepreneurship.
• Provide goals and requirements to incentivise low carbon delivery.
• Local community
• Provide local solutions and knowledge.
• Support sustainability initiatives and provide feedback on community impact.
• Help celebrate success and recognition for great performance.
9. Where can you go from here?
When setting out to reduce embodied carbon emissions, it is important that any path taken aligns with the goals of your organisation, supply chain and stakeholders. In setting the initial scope, consideration should be given to the end goal of identifying areas of high emissions and implementable pathways for emission reductions. There are some general principals to consider as you proceed.
Scoping of emissions
Scoping of emissions for carbon reduction provides a high-level assessment of where the main sources of embodied carbon for a project lie. This can be broken down into phases of a project or types of emissions sources but should always cover both materials and processes. The materials and processes are often tracked by other groups within a project, such as quantity surveyors or procurement teams, and existing data should always be sought before starting from scratch. Turning use and procurement data into emissions can be achieved by utilising emission factor databases or direct supplier data.
Ease of reductions
Within the same groupings of emissions used for the scoping exercise, ease of embodied carbon reductions should be assessed. This should factor in availability of lower emissions alternatives, costs of these alternatives and possible efficiency improvements in the design. Engagement with subject-matter experts within the project and supply chain will be necessary to accurately gauge these factors. A distinction must be made between what is theoretically possible and what is practically possible within the bounds of the project (namely, timeline and cost).
Starting points for emissions reductions
Using the scoping of emissions and assessment of reduction opportunities, the best starting points for embodied carbon emissions reductions are where there are a high proportion of emissions and available emissions reduction opportunities. This approach will achieve the greatest impact with the resources available. An additional weighting factor can be applied to consider the cultural or social impact of emissions sources (e.g. domestic versus imported sources of emissions).
Investment and celebrating success
Moving forward, our water infrastructure programmes need rigorous consideration to minimise embodied carbon. Investment can bring new low carbon process engineering and construction techniques into our toolkit. These opportunities and innovations are often unlocked through partnership and collaboration. The celebration of successes can help take one-off wins into the mainstream, so opportunities and sharing of both challenges and achievements should continuously be sought.
Bibliography
Building Research Association of New Zealand (2024) Low Carbon Design Resource Roadmap
Has developed a low carbon design resource map in conjunction with the Structural Engineering Society of New Zealand, that connects to resources related to emissions reduction in infrastructure.
https://www.sesoc.org.nz/wp-content/uploads/2024/06/SESOC-BRANZ-Resource-Map-Interactive-v2.pdf
BS EN 15978:2011 Sustainability of construction works. Assessment of environmental performance of buildings. Calculation method
This European Standard specifies the calculation method, based on Life Cycle Assessment (LCA) and other quantified environmental information, to assess the environmental performance of a building, and gives the means for the reporting and communication of the outcome of the assessment. The standard applies to new and existing buildings and refurbishment projects, however life cycle stages can also be used to help frame stages of works required for water infrastructure assessments.
https://knowledge.bsigroup.com/products/sustainability-of-construction-works-assessment-of-environmental-performance-of-buildings-calculation-method?version=standard
Climate Connect Aotearoa – Connect people, build partnerships and deliver practical solutions to accelerate the transition to a climate resilient and low carbon Tāmaki Makaurau Auckland – and beyond. https://climateconnectnz.com/
Climate Health Aotearoa – Multi-institutional national research organization that works to generate novel policy-relevant findings at the intersection of climate change and public health. http://www.climatehealthaotearoa.org.nz/
Climate Change Commission – Independent Crown entity, He Pou a Rangi Climate Change Commission provides the Government of the day with advice, monitoring and reporting that supports Aotearoa New Zealand’s transition to a climateresilient, low emissions future. He Pou a Rangi » Climate Change Commission (climatecommission.govt.nz)
Divya Pandey, Madhoolika Agrawal & Jai Shanker Pandey (2010) Carbon footprint: current methods of estimation
This review describes the prevailing carbon footprinting methods and raises the related issues. https://link.springer.com/article/10.1007/s10661-010-1678-y
Engineering New Zealand
Has a summary of various tools, resources and guidance documents available for embodied carbon understanding and reduction. https://www.engineeringnz.org/programmes/engineering-climate-action/sector-specific-resources/buildings/
EPD Australasia
EPD Australasia registers and publishes Environmental Product Declarations (EPDs) and Climate Declarations for businesses in Australia and New Zealand. https://epd-australasia.com/
Infrastructure Sustainability Council (ISC)
ISC provide notes on low embodied carbon materials. These are available at: https://www.iscouncil.org/wp-content/uploads/2022/07/IS-Impact-Notes-Low-embodied-materials.pdf
Kevin Manalo (2024) Carbon Footprint Of Open Cut Pipelines (NZ Context)
This paper outlines outcomes of a study that aims to provide a practical method for contractors to capture their carbon footprint for open-cut excavation and installation of stormwater, water, and wastewater pipelines using actual data. The methodology will encourage contractors to review their work breakdown structures and identify emission sources. The data gathered will then be used to create their own emission inventory, record their carbon baseline emissions, and plan their emission targets. A procedure or guideline will be created to aid in this process.
https://www.waternz.org.nz/Article?Action=View&Article_id=2736
Ministry for the Environment (2023) Measuring emissions: A guide for organisations
This suite of seven documents and tools is for New Zealand-based organisations wishing to voluntarily measure and report their greenhouse gas emissions. The guide includes:
• How to produce an inventory;
• The latest emissions factors for common sources of emissions in New Zealand;
• Help for organisations to easily calculate their emissions through an interactive spreadsheet;
• Examples to show what a greenhouse gas inventory and greenhouse gas report look like.
Measuring emissions: A guide for organisations: 2023 detailed guide | Ministry for the Environment https://environment.govt.nz/publications/measuring-emissions-a-guide-for-organisations-2023-detailed-guide/
Ministry of Business, Innovation and Employment (MBIE)
Through the Building for Climate Change Programme, has developed three emissions mitigation frameworks. These have a focus on the building sector:
• The Whole-of-Life Embodied Carbon Emissions Framework (August 2020). This is available at: https://www.mbie.govt.nz/dmsdocument/11794-whole-of-life-embodied-carbon-emissions-reduction-framework
• Whole-of-Life Embodied Carbon Assessment: Technical Methodology (February 2022). This is available at: https://www.building.govt.nz/assets/Uploads/getting-started/building-for-climate-change/whole-of-life-embodied-carbonassessment-technical-methodology.pdf
• Operational Efficiency Assessment: Technical Methodology (July 2023). This is available at: https://www.building.govt.nz/assets/Uploads/getting-started/building-for-climate-change/operational-efficiencyassessment-technical-methodology.pdf
• The Transforming Operational Efficiency (August 2020). This is available at: https://www.mbie.govt.nz/dmsdocument/11793-transforming-operational-efficiency
• Which Analytical Tools are suited for Transformative Change? (June 2023). This is available at: https://www.mbie.govt.nz/assets/Analytical-tools-suited-to-transformative-change-report.pdf
PAS 2080:2023 Carbon Management in Buildings and Infrastructure
This Publicly Accessible Standard (PAS) specifies the requirements for the management of whole-of-life carbon in infrastructure, including both new assets and renewals.
The standard is available for purchase from standards institutes, but the UK Institute of Civil Engineers has issued a free guidance document on how to apply the standard that provides useful, practical direction: 2023-03-29-pas_2080_guidance_ document_april_2023.pdf (www.ice.org.uk/media/vm0nwehp/2023-03-29-pas_2080_guidance_document_april_2023.pdf)
Structural Engineering Society New Zealand (2024) SESOC Top Tips for Low Carbon Design
This guide has been produced in conjunction with BRANZ and Engineering New Zealand to help inform and assist structural engineers in their efforts to decarbonise their designs, specifically for the Aotearoa New Zealand context. https://www.sesoc.org.nz/wp-content/uploads/2024/05/SESOC-Top-Tips_-V1-2024.pdf
Taiapa, K., Moewaka Barnes, H., & Wright, S. (2024) Climate change and mātauranga Māori – making sense of a western environmental construct.
This research paper follows the work needed for Māori to reconcile their holistic and integrated knowledge systems of te taiao with the concept of climate change. The histories of what caused climate change (colonial, capitalist systems) and the current situation (responses are driven by these same vested interests and ways of thinking) is explained. The paper provides participant voice on the processes Māori experts in te taiao have used to reconcile te ao Māori approaches and actions when engaging with the concept of climate change. Considering the experiences and contexts described in this article can assist the reader to understand that, while important, addressing embodied carbon is not a panacea and that doing so should not be in isolation of other relational approaches.
Kōtuitui: New Zealand Journal of Social Sciences Online, 1–12. https://doi.org/10.1080/1177083X.2024.2350195
Water New Zealand (2021) Carbon Accounting Guidelines for Wastewater Treatment: CH4 and NZO
This document provides guidelines for accounting for methane (CH4) and nitrous oxide (CN2O) emissions from municipal wastewater treatment, discharge and sludge processing in New Zealand. Emissions from on-site septic tanks are also covered. Available from: https://www.waternz.org.nz/technicaldocuments
Water New Zealand (2021) Navigating to Net Zero, Aotearoa’s low carbon journey
A guide to support the water services sector to reduce emissions from operations and capital works, that provides an overarching framework for emissions reduction.
Navigating to Net Zero: Aotearoa’s water sector low-carbon journey : Water New Zealand (https://www.waternz.org.nz/climatechange)
Water Services Association of Australia (2024) Guide to Scope 3 emissions management for the water sector
This guide aims to build understanding of the importance of Scope 3 emissions and facilitate increased consistency and credibility to Scope 3 emissions management across the water sector. It supports utilities to understand how to evaluate their Scope 3 emissions profile, provide agreed principles to help define their Scope 3 emission boundary, and understand complexities and assumptions associated with different reporting methods and tools with the key aim to ultimately reduce material emission sources from value chains.
WSAA Guide to Scope 3 Emissions management for the water sector https://wsaa.asn.au/Web/Web/News-and-Resources/ Resources/Guide-to-Scope-3-emissions-management-for-the-water-sector.aspx
• Consider low carbon products available in the market to substitute traditional products (pipes, manholes, backfill, concrete).
• Consider locally sourced materials to minimise transport emissions.
• Consider hybrid, electric or hydrogen equipment where possible.
• Recycle spoil instead of disposal to landfill (e.g. recover aggregate for use in concrete).
• Create circular economies with supply chains and drive waste to resource opportunities.
• Compare pipe materials , including changes permissible to trench dimensions .
• Consider existing assets that can be reused or life-extended.
• Invest in metering to reduce water use and postpone network upgrades.
Network (Pipelines & Pump Stations)
• Compare manhole materials including corrosion protection.
• Compare asset rehabilitation options (CIPP, spiral-wound, slip-lining) versus renewal .
• Incentivise water reuse / recycling.
• Optimise pipe class / rating in conjunction with trench design.
• Consider recycled backfill materials including proximity to site (recycled crushed concrete, glass).
• Compare trenchless (HDD, pipebursting, micro-tunnelling) versus open-cut
• Incentivise water use reduction devices.
• Reduce potable water use through rainwater harvesting onsite.
• Consider recyclability of materials at end of life to facilitate circular economy contribution.
• Maximise gravity solutions where feasible.
• Invest in storage and smart, staged conveyance operation to reduce peak flows.
• Provide for CH4 & N2O monitoring devices to support operational emissions management.
• Check biogas energy systems minimise fugitive emissions during commissioning.
• Specify material procurement to meet a target emissions reduction against standards or design benchmarks (e.g. for concrete refer base reference mix in NZS 3104, 2.13.3.3).
• Consider sites of significance, te mana o te wai.
• Utilise nature-based solutions for stormwater management.
• Review redundant assets for repurposing.
• Invest in reducing inflow and infiltration.
Treatment
• Align with Iwi & hapu water strategies.
• Consider the impact of concrete: pre-cast versus cast in-situ
• Consider energy efficiency in selection of aerators and pumps, such as variable speed drives.
• Model viable treatment process types to compare operational emissions estimates, and the ability to mitigate them.
• Consider alternative strategies to infrastructure solutions.
• Compare estimated process unit sizes to inform a relative comparison of embodied emissions.
• Consider load shedding and battery storage options to support renewable energy integration.
• Actively protect mahinga kai, te mana o te wai.
Glossary
Term Definition
Anthropogenic emissions
Biogenic emissions
Capital carbon
Carbon dioxide (CO2)
Climate change
Climate target
CO2 equivalent (CO2-eq) emission
Cost-effectiveness
Decarbonisation
Downstream emissions
Embodied carbon
Environmental Product Declaration (EPD)
Global warming
Governance
Greenhouse gas (GHG)
Greenwashing
Green hushing
Kaitiakitanga
Mātauranga Māori
Mauri
Mitigation
Net zero CO2 emissions
Operational emissions
The Paris Agreement
Total carbon budget
Upstream emissions
1 Māori Dictionary.co.nz
Greenhouse gas emissions associated with human activities.
Greenhouse gas emissions resulting from combustion or decomposition of organic material. Fast cycle between plants and atmosphere.
The emissions associated with capital works. The embodied carbon of a project.
A naturally occurring gas, CO2 is also a by-product of burning fossil fuels (such as oil, gas and coal), of burning biomass, of land use changes (LUC), and of industrial processes (e.g., cement production).
Refers to a change in the state of the climate that can be identified by changes in the mean and/or variability of its properties and that persists for an extended period.
Refers to a temperature limit, concentration level, or emissions reduction goal with the aim of avoiding dangerous anthropogenic interference with the climate system.
The amount of carbon dioxide (CO2) emission that would cause the same integrated radiative forcing or temperature change as a specific greenhouse gas (GHG) or a mixture of GHGs.
A measure of the cost at which policy goals or outcomes are achieved. The lower the cost, the greater the cost-effectiveness.
The process by which countries, individuals, or entities aim to achieve zero fossil carbon existence, typically through reduction of emissions in electricity, industry, and transport.
Result from the use or disposal of a business’s products or services.
Also known as embedded carbon emissions or capital carbon, it refers to the greenhouse gas emissions generated during the production and transportation of goods and infrastructure.
An independently verified and registered document that communicates transparent and comparable data on the life-cycle environmental impact of a product.
An increase in global mean surface temperature (GMST) averaged over a 30-year period relative to 1850-1900 unless otherwise specified.
A comprehensive and inclusive concept of the full range of means for deciding, managing, implementing, and monitoring policies and measures.
Gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation, causing the greenhouse effect, which changes the climate.
The purposeful act of misleading or misinforming people about the environmental impact of products or activities.
Purposefully keeping quiet about sustainability goals, even if they are well-intentioned or plausible, for fear of being labelled as greenwashing.
The responsibility of guardianship, stewardship, trusteeship, or trustee1
A dynamic collective of knowledge, systems, and experiences from the Māori worldview.
Life principle, life force, vital essence, special nature, a material symbol of life principle, source of emotions, or essential quality and vitality of a being or entity.
A human intervention to reduce emissions or enhance the sinks of greenhouse gases.
Condition in which anthropogenic carbon dioxide (CO2) emissions are balanced by anthropogenic CO2 removals over a specified period.
The emissions associated with energy used in the operation of infrastructure or an entity.
The global agreement on Climate Change adopted by Parties under the UNFCCC on 12 December 2015, which entered into force on 4 November 2016.
Refers to carbon cycle sources and sinks globally, accounting for fossil fuel emissions, land use, ocean sinks, and atmospheric CO2 changes.
Emissions occurring during the production of goods or services that a business purchases or uses.