Monitoring the movement of diesel fuel in the multi-metric pilot of PRIME, BRGM's experimental platform dedicated to the remediation of polluted soil and groundwater.
© BRGM - Didier Depoorter
BRGM mobilised to maintain or restore soil services
As the European directive adopted at the end of 2025 points out, “soil is crucial for the economy, the environment and society in general”, because of the many ecosystem services it provides. The directive is part of a protective strategy aimed at guaranteeing healthy soils that can have positive effects on human beings, nature and the climate. BRGM contributes through the dissemination of information on urban soils, its public policy support missions and research projects for their protection, regeneration or refunctionalisation.
As well as providing food, maintaining biodiversity and preserving our natural and cultural heritage, the functions of soil – infiltration of water, storage of organic matter and carbon, filtering of pollutants, supply of nutrients – contribute to climate regulation, water quality, and flood and landslide prevention, as well as providing materials and support for infrastructures and human activities.
At the same time, there are a number of threats to the soil. Their functions can be degraded by artificialisation, compaction, erosion, loss of organic matter and biodiversity, nutrient imbalances, acidification, salinisation and anthropogenic pollution, including that caused by war. A thesis by a BRGM employee highlights the persistent environmental contamination caused by modern conflicts.
“Yet the soil renews itself very slowly”, 'explains Dominique Guyonnet, Head of Anthropogenic Risks and Post-Mining. “This renewal occurs through the gradual weathering of the parent rock under the action of the climate – rain, frost, wind, heat – vegetation and other living organisms.” It thus corresponds to the layer between the surface and the parent rock – aquifers included –, which makes up the interface between the atmosphere and the subsurface and interacts with them. This is an area in which BRGM is active, particularly in urban and/or polluted areas.
Towards healthy soil by 2050
The European Soil Strategy for 2030 aims to ensure that all the Union's soils are in good health by 2050. Through the Soil Monitoring Directive, which is its first operational implementation, it is contributing to the achievement of shared objectives: climate neutrality by 2050 and resilience to climate change, the establishment of a clean and circular economy, reversing the decline in biodiversity, protecting human health, halting desertification and reversing the process of land degradation.
Treatability tests on PFASs (perfluoro alkylated and polyfluoroalkylated) at BRGM's experimental pilot plant (Orléans, 2022).
© BRGM
Reference values
In this context, BRGM is a key partner of the Ministry of Ecological Transition in the implementation of this European directive. It has been tasked with three main areas of activity, starting with information on soil quality. Via the BDSolU database, it collects the results of urban soil analyses and distributes geochemical background values that serve as references. As Dominique Guyonnet hopes, “the strengthening of soil monitoring provided for in the directive should increase contributions to BDSolU, which could also incorporate PFAS measurements in soils, of which there are still few.” This is, moreover, one of the characteristics of environmental data, which is by nature incomplete, imprecise and poorly distributed. BRGM is working to overcome this by developing innovative spatial interpolation methods, as in the ISLANDR project.
The institution's information on the geochemical quality of urban soils is invaluable to local public actors: by improving knowledge of their regions, it supports sustainable development based on risk assessment. “This approach is relevant and in line with the national methodology for managing polluted sites and soils drawn up in 2017 by BRGM and the Ministry in charge of the Environment,” says Dominique Guyonnet. “The aim is to determine whether the concentrations measured in the soil present a health risk, given the intended use: housing, education, agriculture, etc.” BRGM therefore intends to offer local authorities a new decision-making tool in the form of local pedogeochemical background maps.
A circular economy strategy
Its support for public policy is also reflected in its active participation in the inter-ministerial plan on PFASs, the plan to accelerate the development of geothermal energy and the study of the prospects for geological storage of CO2.
Finally, BRGM is a major actor in soil research. For example, the European PHISHES project aims to facilitate their preservation, while the PROMISCES project has resulted in an innovative technique for decontaminating soil contaminated by PFASs. “Above all, we have developed genuine expertise in soil reconstruction, with a circular economy approach, by acting on its structure and composition,” emphasises Dominique Guyonnet. In particular, it is working on converting into fertile soil the 8 million tonnes of molasse that will be extracted to create the European Council for Nuclear Research's future underground collider. It is also studying the potential for producing neosols from reprocessed mine tailings. These are just some of the innovative projects designed to preserve the soil and its functions.
Key figures about soil quality
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25.00%of the planet's biodiversity is found in the soil
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60 to70.00%of soils in the European Union are in poor condition
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50.00M€per year: this is the estimated cost of soil degradation to the European Union
BRGM mag no.2: How can we save our soils?
© BRGM
BRGM mag no.2: How can we save our soils?
The second issue of BRGM mag continues to pursue the magazine's ambition: to share knowledge, enlighten and engage in dialogue and to make the Earth sciences accessible to as many people as possible. For beneath our feet lie some of the solutions for meeting today's environmental, energy and sovereignty challenges.
Soils play an essential role for the economy, the environment and society: they support biodiversity, regulate the climate, filter pollutants and store carbon and water. However, these functions are now being degraded by multiple pressures, through artificialization, pollution, erosion and loss of organic matter.
Studying soils, particularly urban and industrial soils, or phenomena such as erosion and pollution, is one of BRGM's missions. The main article in the second issue of BRGM mag is devoted to this major subject.
