What does a soil pollution study cover?
Historical study: collection and analysis of documentation relating to a site (environmental permits, operating permits, etc.)
The aim of the historical study is to gather all the relevant information related to potentially polluting activities that have taken place on a site. During this stage, our design office will ask the municipality relating to the site to obtain the old environmental permits, the old operating authorizations as well as any other relevant document.
This request will also be made to the Department of Permits and Authorizations (DPA), which is responsible for issuing environmental permits in the Walloon Region. The Department of Soil Sanitation (DAS), which manages and controls soil studies in the Walloon Region, will also be called upon during our research.
Depending on the case, the State Archives, Infrabel, or even the War Damages Fund can be consulted. We make every effort to find all the relevant information that will make it possible to specify the investigations to be carried out.
Maps and aerial photos are often useful, for example in the context of an old landfill. This means that we can find extended landfill areas or areas of embankments through the use of old topographic maps or aerial photos available from the National Geographic Institute (IGN). Belgium has had aerial photos since the 1950s that make it possible to find, for example, the traces of ancient sand pits or quarries filled with waste.
The drilling campaign: analysis of ground pollution
At the end of the historical study, we draw up an investigation plan based on all the information relating to former polluting activities, such as hydrocarbon storages, industrial process areas, service stations, mechanical workshops, mechanical workshops, machine and equipment maintenance workshops...
In order to determine the number of drilling operations, ABV Development refers in particular to the Walloon Code of Good Practices, which defines the number of surveys to be carried out according to the characteristics of the so-called “at risk” areas.
Under the supervision of an engineer from our design office, soil samples will be taken by us and analyzed in a laboratory approved by the Walloon Region. In the presence of a shallow groundwater table, groundwater samples are also collected and analyzed.
The drafting of a detailed technical report and recommendations for the remediation of the land
The last step consists in writing the technical report, which includes, in particular, a description of the environmental context, the interpretation of the results of soil and, where applicable, groundwater analyses, for the various pollutants. The approved laboratory provides an analysis certificate presenting the concentrations of heavy metals, mineral oils, chlorinated solvents, and other specific pollutants. These results are examined and compared to the standards of the Walloon Region. These standards are defined according to land use and the sector plan.
There are 5 types of standards in the Walloon Region, called threshold values:
- Type 1: natural area
- Type 2: agricultural zone
- Type 3: residential area
- Type 4: recreation/commercial area
- Type 5: industrial zone
Soil pollution standards will necessarily be more stringent when it comes to land in a natural or agricultural area, than for land located in an industrial zone.
The interpretation of the results makes it possible to determine whether there is pollution in accordance with the standards of the Soil Decree and to integrate this information into a report called the “orientation study”. The orientation study includes the elements of the historical study as well as the environmental context (geology, pedology, presence of groundwater, etc.). The aim is therefore to present the environmental context in its entirety with the description of the survey campaigns, the interpretation of the analysis results and a first recommendation which consists in determining whether a characterization study is necessary in the event of soil contamination.
In the event that the site does not have pollution, we draw up a soil control certificate, integrated into the Orientation Study. This certificate will show the compatibility of the plot with a particular activity, as well as the security and monitoring measures that may be applied to the plot.
Need a soil pollution expert approved by the Walloon Region?
Contact us