Banking up of a polluted coastal zone at the port of Thessaloniki
Topic of the practice
The practice concerns the reclamation of a contaminated seabed port area towards achieving port development, adding of a new high value area and upgrading the surrounding area.
Good Practice Information
The project concerned the banking up of a port coastal zone in order to create new land for port operations and also to sanitise a heavily polluted seabed, being a mixture of polluted clay and mud. The whole work was financed by port's own funds.
The seabed depth of the work area varied from +0.0 m. to –4.0 m. under the sea level. The solution mainly comprised:
- the coverage of the existing seabed with a layer of geotextile
- the gradual banking up with a good quality material
- the installation of a dense grid of vertical drains and the reclamation of the new created land
The work was to a great extent original and required the developing of a new know-how, to meet all the technical requirements. Towards this, the contractors made some patent equipment, like the sea-bulldozers.
It should be noted that the first evaluated solution of the project proposed the excavation of the seabed material (1,000,000 m3), its sea disposal and the replacement by a good quality material, taken from dredging sites of the gulf (2,000,000 m3, sand and gravel).
The evaluation criteria applied during the solution proposed and works execution were a) the environmental effectiveness and the compliance with the legislation, b) the pressure and expectations by the local community and the public authorities and c) the total cost of the works.
The methodology applied by the Thessaloniki Port Authority S.A. is still innovative and can be used by other ports as a good practice concerning the reclamation of a polluted port coastal zone.
Evidence of success
The solution was of great environmental effectiveness, as overcame the problems of the polluted seabed and the dredging & dredged material disposal activities.
Furthermore, it improved the quality of the port landscape and met the expectations of both port administration and the residents (new port land, visual amenity).
The total cost of the work was far cheaper than the dredging and waste disposal solution firstly proposed.
The particular environmental concern shown by the port administration has increased the confidence of the port’s stakeholders, promoted the possitive public image of the port authority to the local community and gave, in addition to, other significant benefits and marketing advantages.
Contact details to obtain further information on the practice
Aristotle University of Thessaloniki
Annex completed on: 12-13-2011