SURICATES - Sediment Uses as Resources In Circular And Territorial EconomieS

Suricates project aim is to increase sediment reuse for erosion and flood protection. Currently, of the 100–200 million m³ a year (i.e. 40–80 mln. tonnes dry weight a year) of dredged sediments in Europe 99% is dumped at sea and/or managed as waste. Zooming in on North West Europe (Netherlands, Germany, France, Flanders) the yearly dredged amount of sediment is 30–50 mln. m³ a year (or roughly 12–20 mln. tonnes dry weight a year).

Suricates project has delivered, tested and operated:

1 Pilot application in the Netherlands:

• Objective: The yearly dredged volumes of sediments fluctuate between 2 and 4 mln. tonnes of dry weight at for Port of Rotterdam. In this pilot application the objective is to reallocate 200,000 tonnes of dry weight sediment which is approximatively 5-10% of the yearly dredging volume for the port. This beneficial use case represents an increase of sediment reuse with a factor 5-10 as compared to the ‘business as usual’ scenario.
• Final delivery: 1 eco-innovative solution saving 219,514.00 tonnes of raw material, with proven upscaling potential to other sites. This is adding 27.5% of current annual sediment amount reused within the EU.

3 innovative processes in Scotland:

• Objective: Scottish Canals is innovating in beneficial use of dredged sediment with the implementation of three applications of a target value of 20,000 tonnes of dry weight sediment including: 1 concrete and sediment application, 2 bio-engineering of top soils with sediments and 3 pozzolanic application.
• Final delivery: 1 concrete application (4 tonnes) for coastal defence against marine erosion at Bowling river pilot site, 1 bio-engineering application (880 tonnes) for topsoil production at Bowling river trial site, 1 pozzolanic application (2 tonnes) for river bank restoration at Stockingfields (Glasgow) and 1 concrete and sediment application (15,480 tonnes) at Lagan. The initial tonnage objective of 20,000 was not reach (i.e. 16,366 tonnes) by the end of the project due to a combination of sediment properties / availability within the dredging campaigns and for the duration of the Suricates project. Nevertheless, all innovative processes were implemented and tested successfully.

1 Circular economy application in Brittany:

• Objective: Improving the La Hisse dehydration site (Rance Estuary, Brittany, France) to increase circular economy activity with sediment and local stakeholders with a target value of 7,000 tonnes dry weight sediment.
• Final delivery: 5 topsoil applications of La Hisse processing dredged sediments have been operated for a total of 46,441 tonnes for agricultural beneficial use against crop field erosion at Plouër-sur-Rance, Saint-Hélen, Pleudihen-sur-Rance , Lanvallay and Corseul (Brittany France). 1 sand application from dehydrated dredged sediment has been use for a dyke trial and a dry-stone wall trial at Lahisse site (Saint-Samson-sur-Rance, Brittany, France) for a total of 28.35 tonnes. 1 topsoil application for a dyke trial and a agricultural soil trial operated at Lahisse site (Saint-Samson-sur-Rance, Brittany, France) for a total of 41 tonnes.

1 dehydration mobile equipment:

• Objective : This pilot equipment has been designed to be tested on site in Scotland following dredging operations to speed up sediment dehydration in order to make it available for reuse applications just after dredging campaigns. Considering (i) sand, silt and clay contents may vary widely and locally, irrespective of the canal, (ii) particle size is a key criterion for cement applications, (iii) organic matter contents are key to select optimal application, the main requirement to provide material from sediment is to separate fine fraction (silt and clay enriched in organic matter), sand and gravel fractions (mainly mineral matter).
• Result: The Dehydration mobile equipment has been built and operated in Falkirk (Scotland) in June 2022 and previously in France (Voies Navigables de France).

1 3-dimensional method for local economic and social acceptability:

• Objective: Development of an integrated tools linking direct and global cost/benefits based on the PRISMA project output for direct cost optimisation and on the CEAMaS (previous Interreg NWE project) for global cost/benefits. Tools tested and used for new project cost evaluation.
• Results: The integrated tools allow an overview of the different potential impacts of specific sediment management approaches in a site-specific context and allow, as appropriate, comparison of the ‘Business as Usual’ scenario with one or more ‘Beneficial Reuse Options’. The integrated tools allow the user to assess different stages of the sediment management decision making process individually or together as a continuous process from designing and optimising the sediment mix to a wider economic impact assessment. The tools have been validated on a number of real projects across all partner countries using real project data. SedEcon validation results were satisfactory, given the complexity of the projects which included, in addition to dredging, beneficial use management options as complex as land reclamation and breakwater construction. The validation of the USAR model was also carried out through the simulation of real projects. The application of this suite of direct cost and economic benefit tools provides valuable new insights into the analysis of the potential benefits of sediment reuse projects at a local and a regional scale in the context of the circular economy and also provides the stakeholder community and the overall decision-making process with the potential capacity to assess sediment management strategies and projects using multi-criteria analyses.