ABSTRACT
ABSTRACT: Industrialisation at the end of the 19th century brought to Flanders increased prosperity but also triggered environmental problems, mainly through ignorance and in some cases due to the absence of regulations. Two examples with impact on the groundwater are given. Former pyrite roasting and production of fertiliser caused an arsenic plume in the groundwater and at least two salt plumes. The source, cause and location of these contaminations vary as well as the effect and the resulting plumes in the groundwater. They present a far different risk for the population and a different appreciation of the need for remediation. Their behaviour, especially the spreading of the pollutants, differs also. The Tessenderlo Group evaluated the risk, took preventive action and started remediation based on a sound analysis of the problem. This was started some 5 years before the official Flemish Soil Remediation Decree became law, regulating a modus operandi similar to the one carried out but with a different definition of terms and governed by strict administrative rules. The remediation proves to be successful but needs to be continued and expanded. Further studies are needed to extend the operation to the deeper part of the aquifer.
