DOP Submersible dredge pumps

The DOP200 is used to pump contaminated sediments to a dewatering plant


Location: Oskarhamn, Sweden
Period : Q1-Q2, 2018
Product type : DOP200 with sand mining head
Contractor : ENVISAN (subsidiary of Jan De Nul Group)

Environmental remediation projects require the highest possible sediment concentration

At Oskarshamn, South East Sweden, the harbour basin had been badly contaminated by a nearby battery factory. As the industrial activity had included the discharge of contaminated waste water over decades, the entire harbour basin – covering some 500.000 m2 – was involved. The contamination included PCBs, dioxin and heavy metals, which slowly spread to the surroundings due to passing traffic.

The hopper dredger 'PINTA' carefully covered the entire area where contaminated sediments were found

The city council awarded the job to remediate the Oskarshamn harbour to Envisan, a company specialized in environmental remediation. Envisan constructed a complete treatment facility on site for treating the contaminated dredged sediments. A filter press was used to dewater the dredged sediments: The dry material was ultimately transported to a landfill nearby, and the process water was treated before discharge.

The hopper dredger in the Oskarshamn harbour

Some 400.000 m3 of contaminated sediments were dredged using a hopper dredger. The dredger passed the area slowly creating minimal turbulence. The hopper hold of the dredger was emptied by means of the DOP200. The submersible dredge pump was lowered into the hopper, where it pumped a mixture of the highest possible concentration to the dewatering plant.

As such, the DOP200 was a small cog in the entire remediation plant set-up.

DOP Submersible Dredge Pump