This good practice is linked to the following European Green Leaf Award indicators:
- Biodiversity, green areas, and sustainable land use
- Waste and circular economy
Purpose
When new construction and development take place, excavated soil is often removed, and new raw materials are brought in from far away. The transport and the need for new raw materials are costly, stressful for the climate and constitute to a significant drain on scarce resources. Therefore, new paths are now being considered, where the excavated soil is stabilized on site and reused either in the same project or in the immediate area.
Helsingør Municipality does not have the authority to decide what should happen with the excess soil from construction projects, but when inquiries are made, the municipality suggests locations where the soil, which is no longer needed, can be moved to. For example, for terrain regulation in land zone areas. It has been like this for many years. Soil has recently been recognized as a highly valuable resource, and moving it has a significant CO2 impact. With thorough and timely planning, you can reduce a building's CO2 footprint by many, many tons. Therefore, Helsingør Municipality works strategically with sustainable land management and tries to spread the message e.g., to the local construction industry.
Initiative description
In 2019, Helsingør Municipality created a forecast for the next 12 years and saw that a very large amount of soil was expected to need relocation. The amount was greater than could easily be accommodated, making it necessary to think in different ways. This helped lay the foundation for viewing soil as a resource rather than waste and for spreading this mindset throughout the construction industry. There are significant savings in both money and CO2 by using excavated soil in other projects instead of transporting it away and later adding new soil.
70% of the soil that is dug up and driven around on the Danish roads is clean, uncontaminated soil. In most cases, the remaining 30%, which is contaminated soil, can either be cleaned or used in other ways, such as for noise barriers along highways.
To learn more about the area, a partnership started in 2021/2022 between the Capital Region, municipalities, Gate 21 and NIRAS called "Partnership for circular Earth and Resource Management". Here, both municipalities and utility companies participate in workshops, theme days, etc. to exchange experiences and share knowledge. There is indeed a great deal to learn. As it stands now, the work with sustainable land management can be divided into three hierarchical scenarios:
- The best option is to avoid disturbing the soil altogether by, if possible, foregoing basements, underground parking garages, and similar features.
- The next best thing is that the surplus soil generated in the project is reused in the same project in one way or another. For example, in an outdoor area around the building. In the case of pipeline work, for example, the soil can also be upgraded and stabilized on resource sites (area dedicated to storing and processing excavated soil) to be subsequently placed in the same hole again.
- If the soil cannot be avoided from being disposed of it is recommended to find local alternatives as close to the construction site as possible to minimize transportation. For example, by having projects within the municipal boundary that can accommodate large amounts of soil.
To succeed with point number 2, it often requires some effort. The excavated soil can rarely be reused exactly as it is; it typically needs to be processed in some way, depending on the soil's quality and consistency. For example, wet and clayey soil can be mixed with burnt lime, which improves its load-bearing capacity. If successful, this will result in soil with enhanced geotechnical properties, thus avoiding the need to purchase new gravel, which is a virgin raw material resource.
Challenges
However, there are several significant challenges that make the implementation of sustainable soil management difficult. First and foremost, a cultural and normative change is needed in the construction and civil engineering industry. Sustainable soil management must be considered very early in the initial planning processes, which can be challenging because it is much easier “to do things the way they have always been done.”
Additionally, the legislation in this area is extremely convoluted. For example, it is unclear when soil is classified as waste and when it is not. If there is excess soil from one project, but a prior agreement has been made with another project to take the soil, this helps avoid the classification of the soil as waste. Once soil is categorized as waste, specific legal requirements come into effect.
Stakeholders
Locally in Helsingør, the stakeholders in this area are the same as those across the country. In Helsingør, this involves the municipality, Forsyning Helsingør, and the entire construction industry, including contractors. Helsingør Municipality finds that there is significant interest in managing soil sustainably from many sectors of the industry.
Conversely, Helsingør Municipality also experiences interest from transporters, who express their interest because their work of transporting soil around the country is likely to be reduced in the coming years. Therefore, it is essential for their business to stay informed.
Results and benefits (Goals)
The benefits of sustainable soil management are significant and clear when measured in both CO2 emissions and financial savings. If soil is handled locally, substantial savings can be achieved in both areas. Additionally, if fewer quantities of soil are transported across the country in large trucks, wear and tear on the roads from heavy vehicles will also be reduced, improving traffic safety. Reusing soil in the local area will further conserve raw material extraction, which is a climate burden.
Lessons and recommendations
In addition to the Capital Region of Denmark, of which Helsingør Municipality is a part, the Central Denmark Region also has a similar partnership, and there is significant experience exchange and knowledge sharing between the two regions, benefiting development in the field.
However, sustainable management remains voluntary and without legal obligation, which means that progress in implementation is slow. The municipality's only authority at present is to refer to this management but cannot enforce it, which is why the transition still needs to be integrated as a cultural change.