The sediments in Valdemarsviken fjord in Sweden were contaminated with chromium from the discharge of untreated wastewater from tannery operations decades ago. The contaminated sediments were dredged, dewatered, solidified and placed as a engineered fill in a nearshore area.
Removing sediments with high dioxin concentrations requires extra care, with modern surveying and tracking techniques from beginning to end, from dredging to a high-tech dewatering process to the final disposal.
Remediation projects are becoming more frequent: Here’s a snapshot of the current state of the industry, including which countries at present have a regulatory framework and/or technical framework in place (and which do not), and what technologies are actively being used.
At the request of the Tunisian Government, a consortium of five dredging contractors has regenerated one of the most eutrophic lagoons in the world into a living lake.
In an extensive pilot study, contaminated sediment dredged from an industrial channel in Venice has been mechanically treated by dehydration at a purpose-built plant near the harbour.
Emissions of Porewater Compounds and Gases from the Subaquatic Sediment Disposal Site “Rodewischhafe”
The 1997 IADC Award was given to this paper which was presented at the International Conference on Contaminated Sediment in Rotterdam, in September.