Sediment tank

Work description

The tank has a total surface area of 270,000 sq. m. and a volume capacity of 1,300,000 m3, with a filling level of +3.00 m above sea level and about 1,415,000 m3, with maximum filling height of +3.00 m above sea level.
In order to realize the tank, plans are to build a Dyke with a cliff long 770 m which shall partially “close” the inlet between Belleli brim (c.d. ex Yard Belleli) and Punta Rondinella.
The cliff-dyke, which surrounds the sediment tank on the sea side, will be created with a trapezoid jetty long about 610 m, with a hight of +3.00 m above sea level and with the protection cliff on the sea front having a hight of +3.50 m above sea level, with a total width on top of 19.00 m above sea level and slopes of 2/3 at the sea bottom.

The protection cliff will form filter given by natural rocks having a weight of 50-1000 kg and by a cape made by 1-3 t rocks, both positioned on a foundation bench of rocks having a weigh ranging from 5 to 50 kg.
The waterproofing will be guaranteed, on the sea front, by metallic piling with a top width of +3.50 m above sea level, which will be fixed so to reach the beginning of the clay level and inserted for at least one meter depth. The metallic piling is therefore the main waterproofing element of the dyke on the entire sea front and is the the containment element of the sediment tank. The piling junctions will also be waterproofed.
For the entire shore front, a plastic membrane with appropriate dimensions will be instead created.

Final environmental solutions

The remodeling of the backfilling, aims to prepare the areas for a subsequent environmental remediation and will be implemented by piling part of the waste material produced during the dredging activities of the Port’s 4th dock.
The remodeling activities will follow the replenishment activities of the area, which will be at +3.5 m above sea level, as specified in the project.

As previously explained, such dispositions are necessary for environmental goals and will involve the landscape appearance, by partially camouflaging the overall visual perception of the area from the sea and from the new Dock Road as well.
According to the project, a total of 410,000 m3 of material will be deposited in two different activity phases: a first phase (phase 1) of approximately 24 months, in which the clay material will be temporally stocked and a second phase (Phase 2) in which the material will be partially reused to recreate the final landscape of the area.