The management of dredging sediments and their valorization are a major challenge for HAROPA - Port of Rouen.
HAROPA - Port of Rouen has been developing partnerships for many years with quarries and construction companies with which it develops innovative projects such as the backfilling of gravel pits with dredging sediments in order to redevelop natural environments and the use of sediments in the construction sector to replace alluvial aggregates to save resources.
Since 2006, HAROPA - Port of Rouen has been involved in a dredging sediment recovery process as part of its dredging sediment management and recovery plan. The Port has thus undertaken not to create any new sediment disposal sites on land, by reusing existing sites on the banks of the Seine. The dredging sediments are thus sorted according to their nature and composition:
- silty materials, the finest ones are directed to gravel pits for landscape reclamation;
- sandy and coarse materials are directed to 5 transit facilities along the river for recycling in the construction sector.
Backfilling of gravel pits
This innovative management method, trialled at the beginning of the 2000s, is of interest to the various partners and stakeholders in the region: it provides an outlet for the port's dredging sediments, it provides quarries with materials to redevelop their water bodies and thus continue their operations, and it allows the recreation of wet ecosystems, thus contributing to the landscape reclamation of the Anneville loop, in accordance with the charter of the Boucles de la Seine Normande Regional Natural Park.
Valorization in the construction sector
HAROPA - Port of Rouen has transformed 5 former storage chambers into transit facilities. The sediments are thus deposited in storage bins for settling and drying and are then taken back by trucks by the construction and quarry companies for direct recovery or in mixture within their installations.
The approach to enhance the value of the project to improve maritime access to the Port of Rouen
As part of the project to improve maritime access to the Port of Rouen and given the large volume of dredging sediments to be managed on land, HAROPA - Port of Rouen launched a call for partnerships in 2008 with construction professionals and quarry operators to find solutions for the total disposal of dredged sediments deposited on land.
The process continued with a call for a contract for the sale of sand and gravel in order to contract with quarries and construction companies and ensure that the Port has an outlet for the project's sediments. The call for a sales contract resulted in four partners being selected.
Between 2012 and 2018, 1.4 million m3of coarse sediments from the maritime access improvement project were recovered in the construction sector and 1.6 million m3 of finer sediments were recovered for gravel pit redevelopment.
Research and development
HAROPA - Port of Rouen is pursuing its sediment valorisation approach by developing research and development projects in order to find new channels for dredging sediment.
Thus, the Port is participating in the SEDIBRICK project in conjunction with HAROPA - Port of Le Havre with the objective of developing port dredging sediments in the terracotta industry. This work, aimed at setting up a pre-industrial pilot, mobilizes the skills of university partners (Le Havre Normandie University, Caen Normandie University, Mines Paris Tech).
In addition, HAROPA - Port of Rouen is working to find ways of recycling dredged sediments from the lower estuary in order to find alternatives, for part of the sediments, to dumping. The Port of Rouen has thus embarked on a new project, called "SEDINNOVE" in collaboration with the consultant NEO-ECO, the Ecole des Mines de Douai and the TOXEM laboratory.