Bijela Shipyard remediation -Montenegro

Description :

In June 2018, VALGO signed a contract with the government of Montenegro for the project of the remediation of the Shipyard Bijela. The work includes also: export of sandblasting grit (hazardous and not hazardous) and contaminated soil.

The site of this shipyard presents risks of pollution of the soil and sea. Health risk for people who are in direct contact with the material or near the shipyard were also identified in case of inhalation of the dusts (but only if swallowing or inhaling). As part of a rehabilitation of the site in new shipyard for yachts, VALGO intervenes for the depollution of the site.

Types of pollutants  :

• Asbestos presence: the presence of fragments of materials containing asbestos is confirmed. No information is available on the presence of free asbestos fibers in the grit.
• The presence of TBT (tributyltin): Ecio-Toxic compound found normally in this type of waste and marine sediments has been identified, but only a maximum concentration (194 mg/kg MS) has been mentioned.
• All heavy Metals are also found in this blasting sand apart from Mercury
• HC products (mainly heavy fuel, used motor oil and Diesel) are also present in blasting sand and in floating phase on more than two hectares and up to 40cm.

Techniques :

Blasting sand cannot be treated in the Balkans and are not suitable to be re-used into thin horizon between surface and ground water (2m maximum)

Evacuation must be done by ship as the site is a port.

No on site treatment is possible in the short time available.

As the ground is really permeable:

• Soil flushing by pumping water in downstream trench and re injecting in upstream trench,
• skim the floating HC in the downstream trench,
• excavate clean soil between surface and floating HC horizon and store on site,
• Excavate and dewater contaminated soil,
• Evacuate by ship,
• Pump and treat groundwater and backfill ground

Détails :

Duration of the works: 21 months
Soil and waste tonnage: 145 000 T  –  Worksite extension: 18 Ha Site
Location: Bijela, Monténégro