What happens to excavated soil? Grondbank as a good example

06/09/2023

We don't always think about it, but soil is an important part of our biodiversity, water management and construction process. That is why it is important to keep an eye on it. In Flanders, Grondbank does just that, and so well that the system is a forerunner in Europe (and the world).

As a contractor, you are faced with a new project. You are going to start building on a building plot and start excavating a building pit. How can you reuse the excess soil in other projects? And suppose the soil is contaminated, what should you do to dispose of it according to the rules?

Grondbank vzw has been a valued partner supporting contractors to manage the use of surplus soil for 20 years. This recognised soil management organisation developed a procedure to guarantee an almost completely circular process of soil processing. If soil is excavated, the building contractor must first have a technical report drawn up to determine the possibilities for use. Fortunately, there is a good chance that the soil is not contaminated, as this is the case for about 60% of Flemish soil. The building owner must then have this technical report certified by a recognised soil management organisation. With a declaration of conformity, Grondbank vzw indicates that the technical report was drawn up in accordance with the rules of the art. Once the report is approved, the contractor has a clear view of the possibilities for use, thanks to the three-part code assigned to the soil. This gives the contractor on site exactly the information he needs: is the soil contaminated or in good condition? What can all this soil be used for? Anyone still wondering afterwards where the soil has gone can also find this out perfectly, as all soil is traced. 

A win for contractors

With this, Grondbank has a complete process where everyone wins. Certainly including the contractors, who know perfectly well what kind of soil they are dealing with and what to do with it. Moreover, they are also insured against their objective liability for environmental damage if they follow this procedure correctly. The introduction of the soil amendment scheme therefore ended the chaos between 1995 and 2004, when contractors without much, or mostly no, environmental information about the soil to be excavated had to find an application in accordance with the new environmental standards anyway. This was the result of the soil decontamination decree that introduced strict standards for new pollution.

Grondbank vzw was set up in 1996 to manage this better and collaborated on the soil disposal regulation that saw the light of day in 2004. This brought a lot of positive changes: from now on, there was insurance for risks in reuse and the traceability procedure provided an ideal basis for fair competition. After a review of these regulations in 2008, the traceability procedure, tasks and responsibilities were anchored in the legislation. Thus, a good basis for soil management. 

With results

And it is paying off. During the first ten years, the use of soil as an alternative to primary minerals doubled. Today, more than 90% (!) of construction waste and excavated soil are recycled or reused. However, this circular story would not be complete without Tracimat. This organisation monitors construction waste management. Like Grondbank, it is an independent non-profit organisation. Flemish legislation does not consider soil as waste, which ensures that its follow-up is not identical. Of course, Tracimat could count on a lot of knowledge from Grondbank when they were established in 2018. Together, they set an example for many countries in Europe (and own country: Wallonia also started a soil management organisation). For instance, the UK has Cl:aire, also a non-profit organisation with soil as its focus. For now, the UK still considers soil as waste, but Cl:aire is working on proper regulations and procedures to enable circular management. France, Portugal and Canada, among others, also knocked on Grondbank's door for clarification.