In a few decades, we have moved from soil remediation to the concept of rehabilitating brownfield sites according to the future uses of the site. Brownfield rehabilitation is a major issue for land use planning: it is part of the objective of controlling urban sprawl (we talk about “rebuilding the city on the city”). From this point of view, a brownfield site will not be treated in the same way if it is used to build a crèche or to install solar panels. This is “depollution according to use”. Two categories of uses are distinguished: ‘classic uses’ for urban renewal (i.e. housing, economic activities, public facilities) and ‘alternative uses’ which include the production of renewable energy, the creation of warehouses or renaturation operations (green spaces).
At the same time, soil is increasingly seen as a resource to be preserved in the same way as water or energy. With this in mind, new developments are focusing on soil reconstruction with a few players taking up positions. At the same time, the sector linked to the recovery of excavated land is tending to become more structured.
Soil decontamination techniques have undergone many changes. After the physical or chemical methods that have long predominated, 'thermal desorption' techniques (at over 650°C), biological techniques (phytoremediation) and, more recently, advanced oxidation techniques have appeared. Whether it is a question of off-site techniques (excavation of the soil for treatment in speci...