We secure contaminated dredged material on land

All sediments that we dredge from the Tidal Elbe in Hamburg are analysed in detail by us. If they are clean enough, i.e. if all legal requirements are met, we return them to the water as an important natural component elsewhere. Today, we can return over 95% of the dredged material to the Elbe or the North Sea. This is not only much more cost-effective and state of the art internationally, but also makes ecological sense.

However, if the analyses by certified laboratories show that the dredged material is too contaminated, we responsibly bring it ashore, where we treat it and place it safely in our landfills.

Since 1993, processing has been carried out in our METHA, an innovative industrial plant that separates the dredged material into clean sand and contaminated fine-grained material, known as METHA material. The clean sand can be used as a building material without restriction. The very dense, clay-like METHA material is either deposited safely in our dredged material landfills or used there as certified sealing material. We are also pursuing other possible uses, for example as a substitute building material in the ceramics industry or instead of clay in dyke construction.

Every year, we remove around 200,000 tonnes of highly contaminated sediment from the tidal waters in Hamburg, making the Elbe and North Sea a little cleaner each time. These are almost always old sediments with industrial pollution from the Elbe catchment area upstream of Hamburg.

The purpose of a landfill is to accommodate contaminated material in such a way that it no longer comes into contact with the environment in the long term. We achieve this at our dredged material landfills by encapsulating the contaminated METHA material on all sides with a seal to prevent rainwater from penetrating or leachate from entering the groundwater. We also use specially prepared METHA material as a seal, which, like loam or clay, allows almost no water to pass through. The little water that does escape is completely drained off via coarse-grained layers, so-called drainage, and cleaned in our SARA wastewater treatment plant. It is then so clean that it can be safely channelled back into the Elbe.

We operate two dredged material landfills in Hamburg: The Francop landfill in the fruit-growing area of Süderelbmarsch - where our METHA is also located - and one in the east of Hamburg, the Feldhofe landfill. The older Francop landfill has now been completely filled and is being secured and landscaped. The final design, e.g. as a public green space or for other uses, is still being discussed. The Feldhofe landfill, on the other hand, still has capacity for many years to come, so that the needs-based disposal of contaminated dredged material will continue to be ensured.

Even if we can continue to safely accommodate contaminated dredged material, our goal is that the sediments of the Elbe will one day be so clean that they can remain in the Elbe without restriction. After all, they are an important natural resource - not least for coastal protection, so that forelands, salt marshes and mudflats can grow in line with rising sea levels.

We will therefore continue to campaign for the greatest possible reduction in pollution through targeted remediation measures in the entire Elbe region up to the Czech Republic. This is because it is fundamentally more efficient to tackle pollution at source than to remove it from the water in the tidal Elbe, where it has already mixed with clean sediments.