Drinking water extraction sites where old contaminants have been identified as (potential) problem substances

This map shows which extractions old contaminants have been found as potential or current problem substances. The map is based on information from the area files for drinking water extraction. In 40 of the 215 extracts considered, substances are found in the extracted water that can be related to the presence of old soil contaminants in cross-standard concentrations. In 54 extractions there are substances in the extracted water that can be related to old contaminants in concentrations of 75 percent of the standard. 22 of these 54 extracts present both parameters that constitute a problem substance and parameters that constitute a potential problem substance. The presence of these substances is often linked to the occurrence of urban areas or (former) industrial activities or landfills in the relocation area. It concerns extractions spread throughout the country. This means that for 72 extracts substances related to “old” contaminants pose a problem or risk. This concerns 57 groundwater extractions and 15 surface and shorewater extractions. For the category of surface water and shorewater extractions, it should be noted that this category of substances occurs mainly in the case of riparian groundwater extractions and only once in surface water extractions. This often involves exceeding the alert values in the Drinking Water Decree (Annex A, Table IIIc) of various hydrocarbon compounds, as well as exceeding standards in the Drinking Water Decree (Annex A, Table II) such as Polycyclic Aromatic Hydrocarbons (PAHs), benzene and benzo(a)pyrene. The inventory does not show that certain substances are much more common than others. The approach to soil contamination takes place under the Soil Protection Act. The standards and signaling values applicable to drinking water sources are generally lower than the intervention values set by the Soil Protection Act (Anonymous, 1986). In practice, this difference in standards leads to discussion about the need to tackle these contaminants. Therefore, the Circular Soil Remediation (Ministry of Infrastructure and the Environment, 2012) offers parties the possibility to also remediate at concentrations lower than the intervention values, but in practice this possibility is not (yet) used.