In the wake of the COVID pandemic, SNF, the flagship of France’s chemical industry, reviewed its economic approach to polymer production.
It turned to greener production, geared towards cardboard manufacturers, with new water-soluble polymers which help to reduce raw material needs.
Extension works were thus carried out to its plant in Dunkirk port, with the building of a first production unit for these new polymers.
The Hauts-de-France RD (Dunkirk Agency) laid the underground networks on the site, which, given the constraint of the water table, consisted in:
- 45,600m³ of excavation works
- Laying of more than 4km of stormwater network (315mm-diameter PVC CR8 up to DN 2 000 135A concrete) with 34 special junction facilities
- Laying of an industrial water residue network in GRP (400mm-diameter DN200) along 90m
- Laying of industrial networks for purge water (800m of DN 315 CR16 PVC)
- Laying of a discharge network in HDPE (570m of 110mm-diameter DN 63)
- Laying of industrial and water supply networks
- Laying of electrical (316 priming pipes) and lighting networks
- Building of a stormwater outfall in reinforced concrete, poured on site
- Building of specific facilities such as flushing units, Venturi flumes and valve chambers
As part of a parallel pipeline order, another SADE team created the wastewater drainage network joining the Gravelines WWTP. This project was executed off the port site.
Worksite specificities
- A new plant on a greenfield site, with no pre-existing facilities
- Terracing (for excavations) and shoring at 5.2m deep under the water table
- D1 type sand, containing low amounts of waste and thus reusable in situ
