Every time we build something – new places to live, bridges and better roads, data centers and storage facilities – we have to dig to make room for the new. What we dig up becomes surplus masses.
When we were kids, digging channels in the sand for the seawater to run through, the surplus masses became valuable building material for sandcastles.
This is (almost) the case with the surplus masses from major construction projects as well: the many tonnes of stone, soil, clay and sand can become valuable resources for others. Smart use of these masses could deliver both environmental and climate benefits, as well as being economically profitable. That’s why circular use of surplus masses is also a key measure in the Norwegian government’s action plan for the circular economy.
Mapping mass management and climate benefits in Indre Østfold
As part of this, Indre Østfold, Rakkestad, Skiptvet and Marker municipalities – collectively known as the Indre Østfold region – are working to build a stronger knowledge base on the handling and future circular use of surplus masses in the region.
NORSUS has been commissioned by the municipalities to survey the current mass "Klimagassreduserende tiltak i masseforvaltningen i Indre Østfold” (Greenhouse gas-reducing measures in mass management in Indre Østfold)..
The researchers find significant potential for sorting and reusing surplus masses: “Information from the region’s mass reception facilities shows that today, the clean masses received are to a very limited extent sorted and reused”, the researchers write in the report.
Gap between future mass flows and reception capacity
Over the next ten years, based on land use plans, construction work in the Indre Østfold region is estimated to generate an annual mass flow of nearly 2 million tonnes. At the same time, reception capacity of the facility is estimated to be far lower, at 300,000 tonnes annually.
Increasing the circular use of these masses could help close this gap, and the NORSUS researchers point to four key measures for circular success: more collaboration, a stronger knowledge base, local intermediate storage sites and more systematic follow-up of these mass flows.
.“The results show both a significant gap in capacity, a considerable potential for better utilisation of the resources and a need for a more systematic collaboration between public actors, contractors and reception facilities to provide a better data foundation,” the researchers write.
Transport and disposal account for most greenhouse gas emissions
Better resource use is economically profitable and reduces pressure on virgin masses – which are in short supply. In addition, the report shows that increased sorting and reuse of masses might deliver significant emission reductions. At the same time, the report is clear on the fact that local and regional collaboration is key for achieving the greatest possible climate benefits.
“The climate accounting shows that transport and disposal account for the main part of greenhouse gas emissions, while the excavation itself has relatively little impact. This makes the location of reception facilities, transport distances and logistics decisive factors in reducing the climate impact”, the researchers write.
Recommended measures for a more climate-friendly and circular mass management
- Sorting, reuse and resale of clean masses
- Requirement for a mass management plan at the zoning/outline planning application stage
- Award criteria for reuse and reduced transport distances in tenders
- Extended assessments of contaminated masses
- Reuse of masses between projects
Larger investments:
- Intermediate storage in the region to enable the use of clean masses across excavation and construction projects
- Treatment facilities for contaminated masses and sorting
- Treatment solutions for invasive species