Pollutec 2025

Waste Forum, Tuesday 7 October 2025, 13:10 pm - 13:55 pm

In operation since the AGEC Act of 2020 to identify and map hazardous waste flows, Trackdéchets has been recording declarations of non-hazardous waste, as well as excavated earth and sediments, since 2025.

Trackdéchets is therefore also an invaluable reservoir of data that can be exploited to promote the circular economy and secure waste streams to ensure transparency and environmental guarantees.

What have we learned so far? What progress can be made to ensure that our waste is managed more sensibly and more virtuously?

Forum organised by BRGM

Water Forum, Tuesday 7 October 2025, 14:05-14:50

Against a backdrop of increasing demand on resources, drinking water operators are faced with the risk of crises over the availability of resources. The innovative PrédiNappe service, co-developed by BRGM and VEOLIA scientific teams, is a digital service for monitoring and predicting changes in aquifer levels.

Developed from BRGM's public MétéEAU Nappes tool, and based on modelling of the entire water cycle, PrédiNappe has functions that meet the needs of drinking water suppliers, to help them anticipate the risks of crises and the groundwater volumes available.

PrédiNappe forecasts in real time the level of resources and the evolution of aquifers for up to 6 months ahead, taking into account climatic and abstraction scenarios. It can incorporate new observation points to enhance the national piezometric network, on which models forecasting changes in aquifer levels are based, while taking into account climate scenarios on different scales for monthly, fortnightly or weekly forecasts. Options for archiving old forecasts mean that it is possible to go back to previous dry years by replaying the forecast and, with feedback, to find out what groundwater levels would have been observed with lower abstraction levels in order to circumvent the risk of a crisis. The tool can also be used to visualise deviations from the average of piezometric measurements (by displaying the standardised piezometric indicator curves) or to approximate the volumes available to comply with the exploitation thresholds of interest defined by the Préfets de département or by the operator.

Feedback on exploited sites is provided in various hydrogeological contexts:

• In the Pyrénées Orientales département, in the Roussillon Plio-quaternary aquifer near the coast,
• In the Bourgogne Franche Comté region, in the Plio-quaternary deep lacustrine gravels and limestones from Vignoles to Beaune,
• In the Hérault département, in the Miocene aquifer of the Castries basin and in the Jurassic limestone aquifer of the Pli Est de Montpellier.

The service offers new ways of dealing with crisis risks to groundwater resources, by means of specific operational and practical functions:

• replaying past situations to anticipate crisis management and future situations;
• infra-monthly monitoring refines the availability of volumes that can be abstracted, taking into account scenarios of higher or lower abstractions and current climate scenarios, and makes it easier to deal with the risk of a crisis;
• the real-time digital service offers a dialogue service with the local authority and the prefectural authorities responsible for coordinating the measures to be taken to deal with the risk of a crisis, such as drought-restriction orders;
• this service identifies the declared volumes accounted for and estimates the difference with the total volumes actually withdrawn from aquifers, facilitating the work of identifying and raising awareness of withdrawals, in order to monitor them more effectively.

Moreover, and this is a key innovation in the context of climate change, with alternating periods of heavy rainfall and periods of drought, the service is a prediction based on a global hydrological model with 10 to 15 years of data, recalibrated over time to incorporate new intense phenomena (which a forecasting system based on learning from past events over a short period does not do).

Finally, a new, modernised version of the web application went online in June 2025, with optimised interface controls that are more intuitive and fluid, easy to use and accessible to all.

Forum organised by BRGM

Circular Economy Forum, Tuesday 7 October 2025, 15:00-15:45

The European Commission's CRM Act Regulation sets very ambitious targets for the recycling of critical metals in Europe. Achieving these objectives requires the monitoring of measurable indicators. The characterisation of urban mining waste, which is dynamic by nature, is a key issue. For waste from end-of-life products, such as Waste from Electrical and Electronic Equipment (WEEE), which contains a wide range of metals with highly variable concentrations and in various forms, eco-organisations concerned with ecosystems or ecology and research centres such as BRGM are involved in sampling and characterising them. Knowing the content of recoverable metals, as well as their location in the various components, is essential for the development of downstream waste dismantling and recycling processes. Digitalisation, the introduction of product passports and the potential of data science could be additional means for responding to the problem of sampling and characterising urban mines.

The expectations of public authorities concern the multi-year planning of the critical metals recycling sector, in a highly unstable geopolitical context. It is crucial to know the potential resource of products at the end of their life or in use, and to understand how it may evolve over time. What is the size of the urban mine deposit and how should the appropriate collection, treatment and recycling sectors be sized?

Lastly, the forum will consider ways of estimating the environmental impact of these sectors, a subject on which eco-organisations are also working.

Forum organised by BRGM

Sites and Soils Village, Tuesday 7 October 2025, 15:55-16:40

Since 2019, the Fiches Techniques Innovantes [innovative technical sheets] project initiated by BRGM on behalf of the Ministry of the environment and in collaboration with INERIS and ADEME, has been publishing new innovative technical fact sheets every year to publicise emerging solutions in the field of polluted sites and soils (SSP - Sites et Sols Pollués). Since 2019, these fact sheets, which have been widely circulated, have introduced around twenty promising new approaches to actors in the field.

From this year onwards, the project will enter a new phase: in addition to innovative techniques, a new series of fact sheets will be devoted to proven techniques that have already been tested and applied on sites for several decades, but are still not widely used. Why such a paradox? Some of the techniques suffer from a bad reputation due to inappropriate use, or more generally to a lack of understanding of the contexts in which they are applied. The new fact sheets, to be published at the end of 2025, aim to overcome these obstacles by providing a contextualised and educational presentation of the techniques, backed up by practical feedback, performance data and recommendations for use. The aim is to rehabilitate these effective solutions and encourage their informed adoption by players in the SSP sector.

This forum will be an opportunity to preview the new fact sheets, discuss their content, and reflect collectively on how best to integrate these tools into operational practices.

Forum organised by UPDS

Sites and Soils Forum, Wednesday 8 October 2025, 10:25-11:10

The aim of the forum is to introduce you to background values: what they are, what they are used for and how to use them. But also what they do not allow and the frequent errors of interpretation. The methodological guidelines for developing these background values were drawn up by a work group in 2018, and have been reviewed since 2023. Their content and developments will be summarised for you on this occasion. Finally, the BDSolU urban soil database, which was launched in 2024, will be presented. How can you contribute data, in what format and how can it be incorporated? But also what results can it provide to help you with your studies? An example of how background values can be developed and used in a city will be presented, along with information on current financial assistance from ADEME.

Forum organised by UPDS

Water Forum, Wednesday 8 October 2025, 11:20-12:05

Rising temperatures and evapotranspiration, less precipitation in summer and more in winter. How do these climate changes affect river flows and aquifer recharging? Are these future changes to the water cycle and the corresponding natural risks the same throughout France? Are hydro-climatic changes affecting water quality? What are the consequences of hydrological extremes on the aggravation of polluted runoff from agricultural sources? The speakers will answer these questions based on the latest scientific findings.

Forum organised by BRGM

Risks Forum, Wednesday 8 October 2025, 14:05-14:50

Storm Chido on 14 December 2024 devastated Mayotte with gusts of up to 226 km/h. There was extreme damage to infrastructures. Likewise, storm Garance, on 27 and 28 February 2025, caused intensive precipitation and run-off which led to natural hazards related to the type of terrain of La Réunion.

From a human and health point of view, Mayotte had many victims. Its hospital found itself in great difficulty, with an increased risk of epidemics. National aid and emergency services were mobilised, including the setting-up of an air and sea bridge and, in particular, rotations of military aircraft between mainland France, Réunion and Mayotte.

From an institutional point of view, a number of decisions were taken:

• the opening of a solidarity fund,
• a curfew,
• a state of emergency in the French overseas territories,
• and the passing of the reconstruction programme Act.

The economic impact is estimated at between around €650 M and €800 M in losses for Mayotte because of Chido and between €160 M and €250 M for La Réunion due to Garance (including the agricultural sector).

In addition to the full support of its regional and national teams, BRGM moved into gear very quickly after the two events and was able to carry out its public service missions, intervening in all areas of geoscience and in particular in support of seismo-volcanic monitoring via REVOSIMA with regular bulletins (this since 2018, the latest to date being issued in May 2025).

Among the lessons to be learnt, particularly with regard to Mayotte, is the importance of instilling a risk culture in the population, and also of maintaining this culture, bearing in mind that language barriers can make it difficult to heed warnings, as well as studying solutions to alleviate the vulnerability of substandard housing.

We need to consider strengthening the system to make it resilient. This will be essential if we are to cope with the vagaries of the climate, which are likely to worsen in the future and are likely to add to economic insecurity.

It is essential to consider an integrated approach, responding to the need for a comprehensive plan ranging from immediate relief to structural prevention (energy management, coastal protection, appropriate urban planning).

Cooperation is essential between all levels of public administration, with coordination between the State, local authorities and insurance companies, and the introduction of sustainable cyclone resilience policies, particularly in the French overseas départements.

Forum organised by BRGM

Energy Forum, Wednesday 8 October 2025, 15:00-15:45

Against a backdrop of accelerated energy transition, and at a time when heat accounts for almost fifty per cent of primary energy in France, geothermal heat is emerging as a strategic solution for decarbonising regions and industrial activities.

BRGM, the leading public authority in subsurface knowledge, and its subsidiary CFG Géothermal, which has been specialising in the design and implementation of geothermal projects for 40 years, will be presenting an up-to-date overview of geothermal potential in France and the opportunities for implementing it. After a presentation of the different types of geothermal energy, their uses and implementation methods (costs, lead times, feasibility) based on actual projects carried out across the country, the focus will be on the opportunities offered by the National Geothermal Energy Plan, undertaken in 2023, particularly for the production of heat and cooling, and on the introduction of appropriate funding mechanisms.

We will also be highlighting the importance for manufacturers of relying on de-risking tools that have been developed to secure investment. Finally, the need for greater cooperation between local authorities, manufacturers and industry players to build a robust, competitive and resilient ecosystem capable of meeting local climate and energy challenges, will be highlighted.

Forum organised by BRGM

Risks Forum, Thursday 9 October 2025, 10:25-11:10

Industrial companies, faced with climate change, wanting to secure your facilities, and needing support in choosing the best locations for your future sites...find out how GéoRisques, the multi-risk assessment system, can help you!

Although specific data on the cost of industrial claims related to climate change in France is limited, it is clear that this sector is exposed to increasing risks and it is essential for industrial companies to integrate these risks into their management and prevention strategies in order to minimise the potential impact on their activities.

GeoRisk's open and reusable data, combined with your expert tools and digital twins, can help you secure your business and/or plan your future locations or relocations.

Forum organised by BRGM

Sites and Soils Village, Thursday 9 October 2025, 11:20-12:05

Since 2011, sargassum has been washing up en masse on the coasts of Guadeloupe and Martinique. Although these algae are a resource for biodiversity when they are at sea, they cause a host of problems when they reach the coast: 

• Environmental
  • Asphyxiation of ecosystems
  • Various types of pollution
  • Beach erosion
• Sanitary
  • Release of toxic gases
  • Presence of arsenic
  • Risks associated with possible pathogens
• Economic
  • Impact on tourism
  • Disruption to fishing activities

At present, sargassum is collected and deposited on land with little or no development, due to the lack of sustainable solutions for managing or recycling it. Deposited on the ground in this way, their storage leads to pollution of all environmental compartments: air, soil and water. When sargassum decomposes, it produces leachate containing arsenic (highly toxic), salt (chlorides) and a large number of organic compounds. These leachates infiltrate the soil, contaminating it and the groundwater. Maturation also leads to the production of toxic gases such as hydrogen sulphide and ammonia.

Collecting seaweed also poses a specific problem in that a large amount of sand is collected at the same time. This has two major consequences:

• environmentally, because it accelerates beach erosion;
• in practical terms, because the accumulation of sand in storage sites quickly leads to their saturation.

In this context, BRGM provides support to local managers. Its activities include:

• the search for suitable new storage sites,
• assessing the impact of storage on existing ground,
• the development of recovery processes for the sand collected, with the aim of being able to redeposit it on beaches.

Forum organised by BRGM

Sustainable cities and regions forum – Thursday 9 October, 15:00-15:45

Faced with the challenges of urban densification, the subsurface has a strategic role in the development of sustainable cities. This will cover both investigation methods for the subsurface, the production of 3D models incorporating its properties (geological, geomechanical, thermal, hydraulic, etc.) and its potential, taking account of existing or future infrastructures, and digital twins, which are essential for managing changes in urban and peri-urban environments. The forum will discuss development needs and new prospects for supporting local players faced with the challenges of planning, developing subsurface resources, the circular economy and resilience to climate change.

Forum organised by BRGM