Remediation of TOTAL acid tar lagoons in Ertvelde

Remediation of TOTAL acid tar lagoons in Ertvelde


At its site in Ertvelde, TOTAL Belgium had three old lagoons containing acid tar, a residual product from the former production method of white oils, which needed to be remediated.

DEC was awarded the design & build contract for the remediation because it has vast experience of many different techniques, as well as the ability to develop innovative solutions.

TOTAL wanted to be absolutely certain that the proposed techniques would work because there are are not many solutions for the treatment of acid tar available.

An additional problem was the emission of sulphur dioxide and the accompanying odour nuisance.

There was also the real danger of finding unexploded bombs during the work because the premises were heavily bombarded during World War Two.

Our solution

DEC proposed a treatment technique in which the acid tar is stabilised using CalDEC (a neutralising additive developed by DEC) and then disposed of on site in an engineered cell.

To solve the emissions problem, DEC developed an alternative excavation technique to eliminate the emissions and odour meters were installed around the site that immediately sounded an alarm if sulphur dioxide was detected.

For the entire operation, a dedicated plant was constructed on the TOTAL premises. It was made completely airtight so that harmful odours could not escape and the odours were neutralised after being collected via a vacuum system. The plant was constructed and operational in a record speed of just three months!

To deal with the threat of potential bombs, DEC deployed a highly advanced preliminary bomb detection system and also established good contacts with the civil defense 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.

Prestigious Safety Award

It is worth noting that DEC was awarded the prestigious IADC Safety Award for this project in 2009. Each year IADC honours one of its member companies that has shown outstanding achievement in safety. The IADC Safety Award is intended to encourage the development of safety skills on the job and to reward those people and companies demonstrating special diligence in safety awareness in the performance of their profession.



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