It asks questions about the draft model procedure and preliminary sustainability assessment as well as a series of more open questions about the scale of the opportunity, any barriers and what recommendations should be made. There are 15 questions in total.
In the linear economy that has been dominant since the Industrial Revolution, materials move from cradle (initial extraction from the environment) through use, to their grave (disposal when a product reaches the end of its life). This approach is now seen as a unacceptable waste of resources. In a circular economy the environmental costs of economic activities are reduced by re-using products or their components at the end of use. In this cradle to cradle (C2C) approach products or their components re-enter the economy after their use, rather than leaving it as waste. In March 2020 the European Commission adopted A new Circular Economy Action Plan For a cleaner and more competitive Europe).
While the public focus has tended to be on a circular economy for consumer products, the size of waste streams from construction and redevelopment dwarf these. An EU protocol for construction and demolition was published in 2016 partly to promote a more circular use of materials. However, excavated soils are excluded from this protocol, despite being also a very large amount of material. Indeed, the amount of excavated rock and soil entering the waste stream in Europe is enormous, >400 million tonnes in 20203.
The available statistics on excavated soils re-use are variable. Media reporting suggests the amount of waste from soil excavated on construction sites is estimated to be five times larger than of household waste produced across Europe, and of this the majority (perhaps as much as 80%) goes straight to its “grave”. However, statistics reported in the EU Soil Strategy (see below) are more optimistic, suggesting “two thirds” of excavated soils were somehow re-used. A 2024 assessment of construction and demolition waste management3 estimated that 35% of “soil waste” was somehow recycled, 40% “backfilled” and 25% landfilled in 2020. However, the data used included large uncertainties. This same study concluded that “100% recycling” is feasible.
In parallel, there are multiple demands for soil and aggregate including: infilling materials, land-raising, engineering such as embankments, ecological engineering (for example for flood management), horticulture and landscaping, both domestically and commercially. Although there are no detailed statistics for the scale of demand and sources of supply, it is a clear that a large proportion of this demand is met from primary resources leading to land take and environmental impacts of excavation. Substitution by creating a more circular economy that better re-uses excavated soil and rock and dredged materials has been tentatively estimated to have the potential to reduce greenhouse gas emissions by 3.6 million tonnes CO2 equivalent each year, and generate annual economic savings in excess of €12 billion.
An obstacle to creating a circular economy for soil is the legal status of excavated soil consequent to the Waste Framework Directive. Case law following the Directive has generally found that excavated soil is assumed to be a waste unless the following conditions prevail:
- It is clean naturally occurring soil that will be reused on its site of origin
- It is demonstrably a byproduct
- It is a recyclate, which meets suitable end-of-waste criteria
- It can be demonstrated that there was never intention to discard the soil (as the definition of waste turns on the intention to discard.
In addition, the Waste Framework Directive sets out some key principles for waste management. It requires that waste be managed:
- Without endangering human health and harming the environment
- Without risk to water, air, soil, plants or animals
- Without causing a nuisance through noise or odours
- And without adversely affecting the countryside or places of special interest.
These have important impacts on soil re-use, for example that the re-use of soils should not lead to net deterioration of the receiving environment, including that they should not exceed background trace element levels at the receiving site.
Revisions to the Directive are under consideration, but these basic conditions and principles will remain.
Member State regulatory interpretations tend to follow an assumption that there is always an intention to discard simply as a direct result of the act of excavation, consequently – except for the emption for on-site use - the excavated soil is inevitably a waste and not a serviceable resource or even byproduct. Moreover, excavated soil management does not always seem to be deeply considered in the developing debate on soil priorities, for example with just a single mention in a recent review of soil priorities by JRC and EC authors. Moreover, statistical information on waste generation and fate is limited because excavated soils and dredging spoils are usually excluded because they do not count towards the recovery rate estimations imposed by the Waste Framework Directive.
Several schemes in Europe (especially Belgium, the Netherlands and the UK) have been set up. Their goal is to facilitate the management and re-use of excavated soils and so encourage a more circular economy approach to soil. Broadly speaking, they formalise the management of excavated soil in a way that is traceable and transparent to regulators that excavated soil is a resource (no intention to discard), a byproduct and / or has achieved end-of-waste.
These re-use schemes tend to centre on excavated materials from urban and development projects and encompass a wide range of materials, and not only “A” and “B” horizon soils, but variously, other naturally occurring subsurface materials such as geological strata, including from tunnelling projects; in-ground demolition materials such as crushed concrete and aggregate; sediments, depending on the particular scheme.
