Carrières-sur-Seine (78)
GPS coordinates :
48.915089, 2.162452
Securing a dangerous site and revitalizing a market garden
Types of layout
Agricultural vocation
Backfilling and securing quarries
Issues :
Farm rehabilitation
Securing the site
Status:
In project
Project presentation
In partnership with the Saint-Germain Boucles de Seine Urban Community and Grand Paris Aménagement, the City of Carrières-sur-Seine has embarked on an ambitious 84-hectare ZAC project. Located near the Montesson market garden area, the sector—situated on former unfilled limestone quarries—poses serious and proven hazards. Securing the site is a complex priority for the City and the public authorities involved, both in terms of implementation and financing.
The collaborative project, led and implemented by ECT, provides a solution to the financing constraints involved in securing the quarries and rehabilitating part of the site for vegetable farming. By reusing inert construction and demolition waste from the local area, the project enables the following to be achieved and financed at no cost to the community or public finances:
- The securing of 16.5 hectares of hazardous land.
- The restoration of 2.4 hectares of farmland and 2.5 hectares set aside for biodiversity
Key figures
Phase 1
- Securing by backfilling
- 17 months of work
- 440,600 m³ of reclaimed inert soil
Phase 2
- Creation of a new market garden plateau
- 185,400 m³ of reclaimed inert soil
hectares
secure underground quarries
hectares
requalified for market gardening
hectares
ecological restoration
trees and shrubs planted
Partners
Project life
Revitalizing a market-gardening area
Following the securing of the quarries, the project calls for the creation of a vegetable garden and the restoration of the area on part of the site:
- Landscape transformation, improvement of the site’s agricultural and ecological quality.
- Land elevation, remediation of degraded sites, and containment of contaminated soil, using inert fill material sourced from local construction sites.
- Traceability and inspection of inert materials brought to the site.
- Evacuation of encampments and demolition of temporary structures.
- Disposal of illegally dumped surface waste through appropriate and approved channels (estimated cost: €495,000)
These operations will create a fertile substrate produced on-site, suitable for market gardening and the resumption of agricultural activity on remediated soils.
The project will include the creation of wetlands and the development of vegetated slopes with diverse plantings (groves, shrubs, and sainfoin grass). These developments will help structure the landscape while promoting biodiversity by creating habitats conducive to birds, pollinators, and small wildlife.
Securing the basement
ECT serves as the project manager for the backfilling of former quarries.
- Securing the site and eliminating the risk of collapse, both above and below ground, by backfilling the tunnels in 75% of the underground area.
- Traceability and quality control of inert soil from local construction sites, used for backfilling.
- Disposal of waste from tunnels through appropriate and approved channels (estimated cost: €534,000)
