Balen and Overpelt are situated in the northeast of Belgium and are only 18 km apart.
The sites operations are complementary and highly integrated. Balen is a zinc smelter and Overpelt is a casting and oxide washing plant.
More than 100 years of industrial activities have resulted in soil and groundwater contamination, both on-site and in the nearby surrounding areas. In 2004, Umicore signed an agreement with the local waste authorities The Public Flemish Waste Company (OVAM ) and the Flemish Minister of Environment in order to remediate the historical pollution at its Flemish sites and some surrounding areas. Nyrstar, which took ownership of Balen and Overpelt in 2007, continues the clean-up commitment.
Contaminated soil and fill material from across both plants has been excavated and the removed materials used as part of the covering of two old goethite ponds. To date this work is about 80% complete. Cleared areas of the sites have been revegetated and grassed and operational areas have been sealed. In the residential areas nearby, Overpelt-Fabriek, Balen-Wezel and Mol-Wezel, affected soil and zinc ashes which had previously been used in the construction of residential driveways have been removed.
More on-site remediation will be progressed once additional landfill capacity is made available. It is anticipated that a new landfill will be constructed on top of the old and covered goethite landfill in Balen. The new landfill will be financed by Nyrstar and used by Nyrstar and OVAM for on and off-site soil remediation works.
Plans to address contaminated groundwater at both Balen and Overpelt have been developed and works will commence once regulatory approvals have been received. The proposed plan at both sites is a hydrogeological containment/pump and treat approach. Part of the contaminated groundwater is expected to be used as process water after treatment, replacing currently extracted clean groundwater; the remainder of the contaminated groundwater will be treated in the wastewater treatment plants before being discharged to surface water in compliance with site discharge licences.
