Bottom ash forms top layer

The former landfill site 't Rikkerink in Ambt Delden is to be turned into a solar park. The landfill is covered with a bottom ash top layer in order to ensure a solid subsurface. A residual material from our waste incineration process is thereby used as a building material.

Bodemas afdeklaag Rikkerink Twence

Bottom ash as a building material

At the former landfill site 't Rikkerink in Ambt Delden, bottom ash is used as an ingredient for the top layer. Together with screened sand and cement, among other materials, it is processed into a certified secondary building material. Three of these top layers are deposited on the landfill mass. The hardened top layer serves as a foundation layer (firm subsurface) for the 28,458 solar panels that will be installed on the 16-hectare site. In March 2021, the top layer was completed and the installation of the solar park started in April. The 't Rikkerink solar park will be operational in September 2021.

Contributing to the circular economy

The recycling of waste products, such as bottom ash, is in line with our ambition to contribute to the circular economy. Under controlled conditions, bottom ash can be used as a substitute for scarce raw materials such as sand and gravel. Bottom ash has already been used in the production of cement clinkers and the laying of a railway viaduct near Deurningen. It has also been used in the circular cycling path between the towns of Denekamp and Nordhorn.

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Remediation through top layer

At 't Rikkerink, the bottom ash top layer has an additional function. The groundwater under the landfill has become polluted over time as a result of rainfall. The solid cement-like top layer ensures that rainwater can no longer seep through the bulk of the waste heap. As a consequence, hardly any, if any, polluted rainwater ends up in the groundwater and in ditches and streams. As such, the top layer is at the same time also a remedial measure (groundwater remediation). Incidentally, Twence is undertaking this groundwater remediation on a voluntarily basis. There is no legal obligation to clean up the groundwater.

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How do you make use of bottom ash?

Bottom ash is what remains after incinerating non-reusable residual waste. This ash lies at the bottom of the incinerator, hence the name bottom ash. In the bottom ash recycling plant, we extract practically all of the metals. Bottom ash can be used as a building material under controlled conditions.

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This is how we made the bottom ash top layer

Zo maakten we de deklaag van bodemas


Circulaire economie
Recycling residual materials
After incinerating residual waste and recovering valuable materials, the bottom ash produced by Twence can be reused as a raw material.
Nieuwe grondstoffen
Less sand and gravel
Thanks to the use of bottom ash as a certified building material, less new sand and gravel will be needed to seal the landfill site.
Bottom ash is not only suitable as a building material for roads, but can also be used in other products such as cement clinkers.
Twence 27 5 217667 Rolf Nijboer thumb

"With a sealing layer of bottom ash and the establishment of a solar park on 't Rikkerink, we are showing that we really are producers of raw materials and energy!"

Rolf Nijboer, project manager Twence

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