Earthbanks - Proof-of-Concept Research and Demonstration of Soil Storage and Reuse, Depots, and Soil Treatment / Fabrication Facilities
In 2022, soils comprised 58% of landfill waste (by volume) (Defra Environmental Improvement Plan, 2023). This is not sustainable and demonstrates poor stewardship of soil and natural resources. Acknowledging this Defra is committed to i) publishing a revised Code of Practice for the sustainable use of soil on construction sites, which will help to reduce the amount of soil sent to landfill, and ii) beginning development of a soil storage and reuse depot scheme to help prevent soil that would otherwise be classified as waste going to landfill, and encourage remediation and reuse of soil; and will start piloting this by 2026.
To support these aspirations the Earthbanks initiative will lay important groundwork to scope blockers to the operation of high-quality soil storage and reuse depots, soil treatment centres and soil fabrication facilities, and will identify practicable measures to remove these blockers.
The lack of local reuse sites or misaligned development phases is often the biggest blocker to soil reuse. Providing a repository / space to hold and maintain soil significantly increases the probability of finding a reuse site and avoids valuable soil resources being disposed of at landfill.
Some Soil Treatment Facilities (STFs) currently operate in England & Wales. Few operate using the CL:AIRE Definition of Waste: Code of Practice (DoW CoP) e.g., to release soil back to the market. Typically, such sites provide a feedstock for large recovery or disposal operations (e.g. for use as daily cover at a disposal site). As such they are considered less sustainable. Current customers of existing facilities should be interested in an improved system, especially where this provides a higher quality product, and a more transparent and efficient system.
An Earthbanks soil depot system would involve high quality facilities for the testing and management of excess soil and ground forming materials including but not limited to:
- advanced digital material tracking systems,
- a comprehensive testing laboratory, and
- a range of management services for soil.
These 'Earthbanks' would play a key role in promoting the sustainable management and reuse of soil in the construction industry, while also protecting the environment and public health. They would allow for further research and demonstration of the sustainability gains of high-quality soil management and manufacture.
Soil depots, as outlined in the Defra Environment Improvement Plan 2023 and under the expected Defra Sustainable Soils Strategy (previously referred to as SHAPE) and associated guidance, will be sites where valued material is “banked”, stored, and protected to enable onward use at third party sites. Such uses could include:
- landscaping soils,
- engineering fill,
- clay materials for lining/capping/flood defence works, and
- inputs into manufactured topsoil and subsoil when certainty of use arises.
This onward use can already be controlled by the CL:AIRE DoW CoP system. Such Earthbanks would be most beneficial where they can be located at multimodal hub locations. Some could make use of mineral extraction sites requiring restoration or habitat creation schemes.