In-depth rehabilitation of a hydrocarbon-impacted site

22/12/2023 - Global Services
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Ortec-Soléo is rehabilitating a brownfield site in Villeneuve-le-Roi in preparation for its conversion to other industrial activities. Earthwork and soil removal operations are necessary and will be part of an extensive measures program to further control nuisances.

Since 2022, Ortec-Soléo, the Ortec Group’s pollution control subsidiary, has been carrying out rehabilitation work on a brownfield site in Villeneuve-le-Roi (Val-de-Marne), which is to be used for new activities. On-site work is scheduled for completion in 2024.

The originality of the project, carried out for TotalEnergies on a former oil and lubricant storage site, lies in its size: 70,000 m3 of soil have been excavated to a depth of 6 metres, including one metre below the water table.

A shielding system to reduce nuisances

Prior to the excavation work, a study phase was necessary to identify areas where soil was likely to cause odour nuisance. This is an important issue, given that the site is located in an urban environment.

To this end, most of the work is carried out under a ventilated containment tent. The aim is to ensure aeraulic confinement to control gas emissions (organic compounds and odours) during earthworks. Equipped with air extraction systems (135,000 m3/h), the tent treats the air with activated carbon before discharge.

To ensure that the excavation work under the tent would be carried out as tightly as possible and to keep nuisance levels under control, Ortec-Soléo implemented a slide rail shoring at the base of the tent, in place of the more conventional embankments required by the geotechnical study. As a result, 8,000 m3 more soil could be excavated with the shoring than with the embankment, all under contained conditions.

Soil transport by river

Polluted soil from the site was evacuated to the Valorterre Ile-de-France soil treatment and recovery platform in Saint-Ouen-l’Aumône. This deposit is estimated at around 50,000 tonnes. Some of it was transported by river. After being transferred by tarpaulin-covered trucks from the site to the port of Villeneuve-Saint-Georges (3 km away), the soil was loaded onto 1,500-tonne barges, and then received at the Valorterre site equipped with a special quay. This transport solution is more environmentally friendly as it limits the number of trucks on the road, and the associated GHG emissions.

The project involved the continuous mobilization of some ten Ortec-Soléo employees. Brunet and Ortec Industrie Ile-de-France provided electrical and oily water pumping services.

The client was very satisfied with the progress of operations and the control of nuisances. “Zero accidents” observed also demonstrate the importance given to personal safety issues.

Key Figures:

  • 70,000 m³. Volume of soil treated on site
  • 6 meters. Level of the deepest impacts measured
  • 115 x 40 m. Size of one of the two tents installed. The second one measuring 110 x 40 m
  • 135,000 m³/h. Hourly volume of air extraction from the tents
  • 2 years. Duration of works
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