Depollution – Factory – Lannemezan (65)


Soil remediation work, undertaken by VALGO, has made it possible to treat soil contaminated by PCB leaks on the ground of a former electrical substation in the Hautes-Pyrénées department.

The thermal desorption on site, the technique used on this pollutant, was a first in France, on such an important soil matrix by an on-site process.

Depollution - Factory - Lannemezan (65)

Key aspects of the project:

On this site, the pollution was spread over two zones: a tank zone on which the pollution was concentrated in a few locations but up to 3 meters deep and a surface pollution.

After a laboratory study to determine the conditions (temperature and duration) necessary for the desorption of the pollutant, pilot tests were carried out on a sample before the installation of a secure, semi-automated system, assisted by daily human monitoring to make the most of the installation.

Depollution - Factory - Lannemezan (65)

Key figures:

  • 3000 m3 of soil contaminated with PCBs
  • 5000 tons of impacted land
  • Device divided into two lines for heating and treating vapors


Types of pollutants: PCB and HCI
Treatment: thermal desorption in situ
Duration of the works: 48 months
Location: Hautes-Pyrénées


Technique de désorption thermique de sols pollués sur le chantier de l'usine de Lamnezan