Our Execution of works

Ensuring safety

Making a site safe meets not only environmental objectives, through the preservation of common resources (groundwater, soil, biodiversity, etc.), but also health objectives to protect site users.

COLAS Environnement implements a wide range of actions to make sites safe. They may consist of:

  • Managing/identifying and screening hazardous waste into approved channels;
  • Cutting off transfer routes into the groundwater, soil and air;
  • Eliminating concentrated sources of pollution;
  • Protecting a drinking water supply;
  • Reaching the thresholds set by the Residual Risk Analysis.

Interventions designed on a case-by-case basis thanks to mastered methods and technologies: in-situ treatments, under-slab depressurization, hydraulic pumping barrier, reactive permeable barrier, diaphragm wall and hazardous waste management.

A constantly evolving work methodology based on the know-how and experience built up by Colas Environnement over the past forty years.


Brownfield conversion

We are committed to working with you to combat the artificialization of land through the rehabilitation of brownfield sites. We put our expertise into practice during the rehabilitation of polluted sites to make it compatible with future uses.

Our teams thus give new life to degraded land by carrying out rehabilitation work in all environments:

  • Off-site treatment: sheltered excavations, screening, removal of soil and hazardous waste for treatment, removal of tanks, etc.
  • On-site treatment: ventilated screening, biopiling, landfarming, ground clean-up, water and/or soil gas treatment, etc.
  • In-situ treatment: pumping & treatment, vacuum extraction, venting-sparging, thermal desorption, pilot tests, etc.

By enabling the reuse and recycling of brownfield sites, Colas Environnement is contributing to the French national objective of “Zero Net Artificialization”!


Water treatment

At a time when water resources are becoming increasingly scarce and restricted, Colas Environnement’s expertise in soil and groundwater pollution remediation means that it can offer modular water filtration solutions.

Our treatment processes are customized and capable of treating all types of pollution using fully mastered technologies:

  •  physicochemical treatment,
  • aerobic and/or anaerobic biological treatment,
  • biofilter, filtration through filtering media (ion exchange resins, activated carbon , iron oxide, sand, etc.),
  •  skimming NAPL phase, etc.

Numerous clients and partners trust us to manage their water treatment problems, such as lowering the water table in the context of earthworks, construction and development work, sensitive and vulnerable polluted groundwater, industrial processes or storage basins before discharge into the natural environment.
Thanks to its know-how and the projects we carry out, Colas Environnement helps to preserve this resource, which is not inexhaustible.