FGU – Determination of normal background concentrations in urban and peri-urban soils in France
Since 2010 in France, the ADEME and the BRGM have studied the conditions for defining normal background values in the soils of urban and peri-urban areas. The FGU project aims at providing information about the usual chemical quality of soils at the city scale, to meet the challenges of contaminated sites management. The national methodology is based on the comparison of concentrations measured in contaminated sites to values representative of the natural state of local soils – possibly influenced by a diffuse pollution – in order to define the remediation actions. These background values are also used to assess if excavated soils may be deposited in a plot, without any risk of degrading the chemical quality of soils in the plot. The project includes the design of the BdSolU database devoted to collection of the background analyses measured over the whole french territory during the contaminated sites studies, the leading of a working group that involves private and public stakeholders, and the writing of a methodological guide to describe the workflow, the tools and the methods advised to determine background values.
eOde is involved in the project to establish the statistical and geostatistical treatment applied to data saved in BdSolU. The aim is to provide distributions of background values for target chemical components at the scale of homogeneous geographic entities in soil layers. It is also planned to map the chemical components concentrations using geostatistical methods. Results will be delivered to the public through a web service.
eOde was consulted to write the chapter of the guide about the statistical and geostatistical data analysis and to take part in the meetings of the working group. Various real data sets are also under study to define a systematic and automatic process of data analysis.