Landfill Techniques

Capping of a goethite pond for Nyrstar (fka Umicore, Balen, Belgium)

During zinc production by the company Nyrstar formerly known as Umicore), a residual product 'goethite' is released in sediment form.

This goethite sediment is stored in basins at the premises in Balen. One of the basins with a surface area of 20 hectares was filled in 2003 and had to be sealed in accordance with environmental regulations.

Our job consisted of:

• Design, stability calculations, concept for capping work;
• Consolidation work;
• Processing filler materials in accordance with the remediation work at the site;
• The supply and construction of a full capping system and drainage system with separate drainage of surface water and consolidation water;
• Dyke reinforcement work.

The sealing consisted of 200,000 m² of bentonite mats and 200,000 m² HDPE membrane. In total, 700,000 m³, earthmoving was performed and 50,000 m³ of dewatered dredged sediments was used as rooting layer on the banks.