In 2025, Tritech Solutions B.V. carried out the first phase of sealing the former Doonweg landfill in Eerbeek. The project covers a total area of ​​approximately 36,000 m² and involves installing a sustainable sealing system over the existing mound of steel slag.

From steel slag to sustainable sealing

Steel slag is a by-product of steel production; at the Doonweg site, it had been used as a temporary top seal and as a foundation layer for a solar park. However, the steel slag failed to provide the sealing performance originally intended, necessitating a new sealing solution.

Trisoplast as the new sealing layer

The application of Trisoplast creates a reliable mineral sealing layer that significantly limits rainwater infiltration into the underlying steel slag. Consequently, the new sealing system contributes to better management of water runoff from the landfill.

Unique setting

The landfill is situated in a wooded area on the edge of Eerbeek, directly adjacent to a campsite. This required special attention to the surrounding area, logistics, and the minimization of nuisance during execution.

Phased execution

The work is being carried out in phases. The first phase, covering approximately 36,000 m², was completed in 2025, marking a significant step toward permanently improving the sealing and environmental management of the former landfill.​