Implementing Sustainability in the Geotechnical Industry

Introduction
Sustainability encompasses three broad areas: social, environment, and economics. As geotechnical engineers and contractors that work in a for-profit industry, it can feel overwhelming to try to figure out how we fit in with the sustainability movement that is gaining steam across the world, across the country, and even in our local jurisdictions. A great place to begin the sustainability journey is with the United Nation’s Sustainable Development Goals, known as the SDGs. These 17 goals, which are presented in Figure 1, break sustainability down into smaller and easier to understand areas. As companies or individuals, we can select a subset of the SDGs where we can begin to focus our efforts to do our part to promote development in a way that aligns with our own goals and values. This article will focus on how companies in the geotechnical industry can use the SDGs to begin or amplify their sustainability journey and impacts, and how the legislative and regulatory landscape is changing in a way that encourages us to incorporate these goals.

Figure 1. 17 UN Sustainable Development Goals

Social Sustainability
For geotechnical engineers and contractors, SDG 3 “Good Health and Well-Being” is a goal that we can identify with because safety is central to everything we do. The benefit of expanding our safety culture to the more encompassing idea of good health and well-being, is that we can begin to look beyond just the physical safety of employees and colleagues and address concepts like mental health, burnout, work-life balance, and inclusive offices and worksites. This improves the workplace for everyone. Culture of Care (buildculture.org) is an organization that provides guidance for companies looking to do more in this area. This organization provides a great starting point for improving office and worksite cultures, and they can also provide connections with consultants to help your company take even bigger steps forward.

SDG 4 “Quality Education” and SDG 8 “Decent Work and Economic Growth” are places where our industry excels. With strong professional organizations, like the American Society of Civil Engineers, it is easy for our employees to continue to grow their careers with new knowledge and improved practices, ultimately leading to personal and corporate economic growth.

SDG 5 “Gender Equality” and SDG 10 “Reduced Inequities” are places where our industry is striving to do better. Actively participating in groups like ASCE Geo-Institute’s Outreach and Engagement Committee or the Deep Foundations Institute’s Women in Deep Foundations Committee, encourages all types of people to enter our industry, helping to better align our demographics with those of the communities we serve. Looking outward, it is vital as organizations that we reach out to our communities to introduce young people, particularly those from underrepresented groups to civil engineering. Our industry has incredible career opportunities, but most people simply do not know what we do. Again, many of our professional organizations provide opportunities to get involved in our communities and beyond, such as with local universities and colleges or with your alma mater.

Environmental Sustainability
When we look to reduce our environmental footprint, carbon is a great place to start. Carbon emissions touch on SDGs 12 “Responsible Consumption and Production” and 13 “Climate Action.” To better understand the impact that lowering our carbon can have on SDG 12, we can define how carbon emissions are categorized by using the scope method outlined by the Greenhouse Gas Protocol as shown in Figure 2. Scope 1 includes direct emissions from burning fuel, e.g., diesel, gasoline, natural gas, and heating oil. Scope 1 carbon is emitted at the point of use. Scope 2 are emissions from the use of electricity. In most cases, where the energy is used is not where the emissions from that energy is released, but similar to Scope 1, a company has direct control over how many resources are used to provide fuel and energy to its operations.

Figure 2. Scope emissions graphic (courtesy of Erica F. Russell)

Scope 3 emissions cover everything else. This includes operational emissions like business travel, e.g., flights, fuel burned in rental cars, and transport of materials and waste. It also includes the embodied carbon of the materials we use to build our foundations, structures, and infrastructure. These are the carbon emissions associated with manufacturing those materials before they arrive on our sites. For our clients that are the owners of the project and for those of us that perform construction, Scope 3 emissions are our largest emissions. This is mostly due to the large environmental impact of materials like Portland cement and steel, which are the two main building materials of our industry.

Why carbon emissions and SDG 12 are inextricably linked, is that when we reduce our consumption of concrete and steel, we also reduce our carbon emissions. This also helps us mitigate the worst effects of climate change and addresses SDG 13. How we reduce our carbon emissions depends on what part of the industry we serve. For example, if a company performs site investigations, then their own impact can be reduced by using lower carbon site investigation tools, e.g., geophysics versus boreholes. However, their influence on site selection may be more impactful because a proper site location can lead to a much smaller scope for earthworks and foundations. If a company designs foundation systems, then their own emissions may be small as they are only associated with working in an office, but their efforts can be focused on reducing the Scope 3 emissions for their clients. This can be through correctly selecting certain soil design parameters and requesting load tests to verify capacities and reduce factors of safety. We are bound to design safely, but we should also be bound to design correctly and without excess conservatism in order to reduce the environmental impacts of our designs. If we are a contractor, then we can work to reduce the waste materials on site, use more efficient and modern equipment to reduce fuel consumption, change to electric or hybrid equipment when possible, and also use alternative materials if we can. By bringing all parts of the geotechnical design to the table, we can work together to find the lowest carbon solutions for our projects.

In order to find a lower carbon solution, we need to be able to calculate the emissions of our project. There are various tools available online, but we recommend using the free Carbon Calculator spreadsheet that was built specifically for the geotechnical industry by the European Federation of Foundation Contractors (EFFC) and the Deep Foundations Institute (DFI). This calculator can be downloaded from geotechnicalcarboncalculator.com. This tool is simple to use, yet is certified to ISO, GHG Protocol, and PAS, meaning that it is a useful way to compare carbon calculations across companies. However, the calculations made using this tool are not certified. Those would have to be verified by a third party if the carbon calculations need to be made to that level.

To demonstrate how this carbon calculator can be used in practice, carbon emissions were calculated for both the base bid and value-engineered ground improvement designs to be installed beneath a proposed school building in Massachusetts. The base bid required installation of a rigid inclusion ground improvement solution, whereas the value-engineered design replaced a portion of those rigid inclusions with aggregate pier ground improvement. A comparison of these carbon calculations as well as the distribution of emissions by source are shown in Figure 3. The value-engineered design generates approximately half of the emissions of the base bid design. For reference, the 1,300 tons of carbon emissions from the base bid design is the equivalent of emissions from 260 US cars running for one year and would require a forest the size of 835 football fields to absorb it all.

Figure 3. Carbon emissions comparison of the base bid (Original) 
and value-engineered option (VE) ground improvement designs for a 
project in Massachusetts. These carbon emissions were estimated using 
the EFFC-DFI Carbon Calculator, are for use during the bid process and 
have not been certified by a third party.

As with most ground improvement and foundation construction, the carbon emissions of a project are largely determined by its Scope 3 emissions, the embodied carbon of the materials used. In this case study, emissions from cement account for 74% and 78% of the total emissions for the base bid design and value-engineered design, respectively. While the value-engineered design also includes benefits such as fewer working days and decreasing the diesel fuel consumption by approximately half, the reduction in cement usage by a third and steel by 90% is driving the reduction in carbon emissions.

Carbon calculations can also be used to identify typical sources of carbon emissions for various types of projects and have the potential to guide innovation and the usage of green building materials. For example, if all the steel used in the ground improvement or deep foundation solution was 100% reused or made of secondary steel, emissions associated with steel would be reduced to zero. 

There are many considerations that project teams and client must account for during design and construction.  Keller is leading the industry by including sustainability and focusing on the carbon calculations to help designers and owners make these decisions.  As our companies and clients set goals to achieve net zero emissions in the not-so-distant future, utilizing the carbon calculator now can lead to innovative designs and competitive bids and get us into the mindset of lower carbon design before it is mandated.

Federal and State Climate Legislation
In the past two years, there has been significant movement around climate legislation at both the federal and state levels. Highlights of some of the actions at the federal level as well as those specific to the State of Massachusetts are below.

Inflation Reduction Act (August 16, 2022)

• Extends the Investment Tax Credit and Production Tax Credits for geothermal projects beginning construction before January 1, 2035, and January 1, 2025, respectively.
• FHWA reimburse/incentivize use of low-embodied carbon transportation materials on its projects.
• $100 million for EPA to develop program to identify and label low-embodied carbon materials.

Proposed SEC Climate disclosure rules, “The Enhancement and Standardization of Climate-Related Disclosures for Investors” (March 21, 2022)

• This proposal, if adopted, would mandate climate-risk disclosures by public companies as early as fiscal year 2023 in order for investors to better evaluate the impact of climate related matters on those companies.
• Quantitative disclosures include items such as greenhouse gas emissions for Scopes 1, 2 and 3.

Massachusetts Executive Order No. 594: Leading By Example: Decarbonizing and Minimizing Environmental Impacts of State Government (April 22, 2021)

• Establishes a goal of net zero greenhouse gas emissions by 2050 for state facilities and operations, with an interim goal to reduce emissions to 45% of 2010 levels by 2030.
• Targets include reducing the embodied carbon in building materials and building electrification that involve technologies such as ground-source heat pumps and thermal renewable energy.

In the geotechnical and civil engineering sector, we are not typically the owners of the projects on which we work, which means many of these actions will not directly apply to our companies. However, because these laws and initiatives at the state and federal levels will impact our clients, we should expect to see the requirements flow down into what we engineer and build. This may include reporting our Scope 1, 2, and 3 emissions and making net-zero commitments for our companies and our projects. We also expect legislation and regulatory requirements to venture into areas of social sustainability, like reporting on the diversity of our companies and project teams and articulating how we engage with and support our local communities. 

Conclusion
As our governments and clients become more strategic in tying legislation and funding to sustainability, this momentum requires a reassessment of our industry’s current practices and creates opportunities for innovation to address these new demands. With tools like the EFFC-DFI Carbon Calculator, we can begin to offer solutions that directly consider emissions in the design process. By using the framework of the UN SDGs, as geotechnical engineers and contractors we can address sustainability in a more holistic way, and better serve the communities in which we work.

If you want to learn more about how sustainability in geotechnical design and construction, please contact Kimberly at kimberly.martin@keller-na.com.