Husum is a German seaport, well known for its tourism, exhibitions, wind industry and shipyard. The shipyard bottom was polluted with TBT (antifouling). This was an extraordinary challenge because Husum is a seaport with strong tidal currents, up to more than 4,00 metres.
The ‘Husumer Locks’ protects the inner city from flooding during spring tides and extreme weather conditions. During our dredging operations, the locks were closed to ensure a stable water level in the harbour. Due to this, 2 powerful water pumps (with a capacity of 15,000 m3 per hour) were installed to discharge the current of two small rivers into the harbour.
All dredged sediment was pumped and stored into geotextile dewatering containers. Two computerised high output Polymer Units were operational to inject dry polymer (flocculates) into the dewatering containers to optimise the dewatering process.
Huge amounts of silt was dewatered on the storage site. Finally, more than 45,000 m3 of contaminated silt was dewatered and stored.