IADC presents Safety Award 2009 to DEME

The Board of the International Association of Dredging Contractors (IADC) has presented the Safety Award 2009 to DEME Environmental Contractors (DEC), for its safety performance its project titled “Remediation of the Acid Tar Lagoons in Rieme, Belgium”.

Each year IADC honours one member company which has shown an achievement in the area of safety.

The operation that DEC performed in the remediation of the toxic and acid tar lagoons in Rieme demonstrated that the expertise the company had developed could be applied in the most challenging circumstances.

DEME and its environmental subsidiary DEC are both ISO 9001 and ISO 14001 certified companies.

The Acid Tar Lagoons project in Rieme

On its premises in Rieme, TOTAL Belgium has three old lagoons containing acid tar, a residual product from the former production method of white oils. In total, about 200,000 tonnes of lagoon material was present.

DEC was awarded the design and build contract for the remediation of the acid tar lagoons.

There are not many available solutions for the treatment of acid tar and Total wanted to be certain that the proposed techniques would work. DEC proposed a treatment technique in which the acid tar is stabilised, using CalDEC (a neutralising additive developed by DEC) and then disposed on site in an engineered cell.

A problem which occurred was the emission of sulphur dioxide and the accompanying odour nuisance. DEC developed an alternative excavation technique to eliminate the nuisance for all those on and near the site.

Odour sensors were installed around the site that immediately sound an alarm when

sulphur dioxide is detected. For the entire operation, a specific plant was constructed on the TOTAL premises. It was made completely air-tight so that harmful odours could not escape.

The odours were neutralised after being collected via a vacuum system. The plant was constructed and made operational after three months.

The premises were heavily bombarded during World War II (after the construction of the acid tar lagoons). As a result, unexploded bombs (UXO) were found and were taken care of during the work.

DEC developed preliminary bomb detection methods and established contacts with the civil defence organisation.

Finally, a large scale water purification system was also designed, constructed and tested for the treatment of the contaminated groundwater and process water that is discharged during production.
 

Source: Baird Maritime