BeNeKempen

From the mid-19th century to the mid-seventies, zinc and lead were being refined in the Campine region (northern region of Flanders) by heating up ores and coal extracted from the area. For the refining of zinc and lead, ores and coal were heated to 1400° C inside tubular muffles. Metal vapours were condensed inside a condenser, collected and transferred into casting moulds. The residues (ashes, slag and muffles) from this pyro-metallurgic process were used in the hardening of roads and industrial terrains. Volatile metals not captured inside the condenser, condensed on dust particles and subsequently were expelled through the smoke stacks. As a result of these emissions, a widespread area became polluted through the deposit of dust contaminated by lead, zinc, arsenic, and cadmium. The discharge of the waste water from this industrial operation into the surface water has led to the contamination of several layers of groundwater.

Currently, a great deal of attention is being paid to this contamination. In the Netherlands, the project agency 'Actief Bodembeheer de Kempen' (AbdK or Campine Active Soil Management ) has since 1998 been involved in the development of a socially responsible management program of soils contaminated with heavy metals in and around the Dutch Campine regions. In 1997, a covenant was signed between the Flemish government, Umicore NV and the OVAM to implement remedial measures to deal with the contamination on existing and former Umicore sites and their immediate vicinity. In 2004, the same parties signed an addendum to this covenant for remedial measures across a broad area.
In view of the cross-border character of the pollution, the then Flemish minister of the Environment and Agriculture and his Dutch colleague agreed on 22 November 2002 to form a partnership to find solutions to this problem. To substantiate this agreement, the parties drew up a joint project proposal for the cross-border remediation and/or management of the heavy metal problem in the Campine region.
As a consequence, at the end of 2004 a start was made with the Interreg project BeNeKempen, this with support from the European Communities. Flanders and the Netherlands are combining forces to implement a cross-border solution and/or to manage the soil and water pollution by heavy metals caused by the former thermal zinc industry in the Campine region.

The spread of the pollutants and the effects of such pollution on people and the environment have been examined since the beginning of the eighties and most of the spread has been mapped. Currently, it is known that in the Flemish provinces of Antwerp and Limburg 490 km of roadways have been constructed with materials containing residues of zinc and/or lead distributed over the former industrial terrains. In the Netherlands, 833 km have been registered. The spread of ashes, slag, and muffles used in the construction of public roads, bicycle paths, and hardening of plots of land, the spreading of dust and the depositing of sludge during flooding or the dredging of rivers and streams have led to widespread distribution of the metals and the contamination of some 700 km2 with zinc, lead, cadmium and arsenic deposits. The heavy metals have seeped deeper into the groundwater. Taking the involved communities as a yardstick, a project area has been delineated covering some 5.000 km2. For what concerns effects on health, it is known that aside from Pb, the Cd content will bring risks even in relatively low concentrations.

The information gathered by the Netherlands and Flanders over the past 25 years by several authorities has never been assimilated. The first stage of the Interreg project therefore involved the consolidation of the existing data in Flanders and the Netherlands. This existing knowledge has been used to develop feasible solutions that are widely supported.

The activities within the scope of BeNeKempen were being divided amongst study groups. These study groups consisted of various administrations (on regional, provincial and municipal levels) and knowledge centres. The study groups were complemented by other interest groups depending on their topic: zinc ashes, risk evaluation, agriculture, water and natur.

The study group focusing on zinc ashes developed methods for the removal and the safe reuse of zinc ashes. Given the massive use of zinc ashes in Flanders alone for the hardening of roads, squares and ramps, a complete removal of these ashes appears unlikely, even in the long term. Thus more efforts were devoted to optimizing the reuse of the zinc ashes in existing roadways containing such ashes so as to minimize the risk of recontamination.

The study group on agriculture dealt with problems related to the contamination of farmlands and the increased absorption of metals by plants and vegetation. An important task is the definition of cultivation recommendations by which the exceeding of the norm for crops can be avoided. In addition, alternative cultivation of the soil and alternative crops such as energy plants were considered.

The study group on water gained a clear insight into the flows of water and the spread of the pollution around the whole region. Ultimately, a method needed to be worked out to decontaminate and/or manage rivers and streams in the region, taking into account the input and output of the pollution.

The study group involved in risk evaluation has worked on establishing the harmonisation of risk evaluation in the Netherlands and Flanders and offers support to the various other study groups. Risk evaluation is of paramount importance during a later weighing of actions, taking into account the remediation costs or the management expense.

The project ended in November 2008.