Exterior view of the METHA large-scale dredged material treatment plant showing conveyor belts and mounds of dried mud
Above water

METHA - the washing machine of the Port of Hamburg

What happens if the sediment that needs to be dredged from the harbour is too heavily contaminated? It is taken to the METHA – a huge facility that processes, separates and dewaters the material from the Elbe riverbed. The treated sediment is then reused or safely disposed of at our dredged material disposal sites.

Interior view of the large-scale dredged material treatment plant METHA shows two hydrocyclones made of red pipes with people in work clothes next to them
Hydrocyclones: These centrifugal systems are the centrepiece of the METHA.
Interior view of the METHA large-scale dredged material treatment plant shows a hydrocyclone made of red pipes
Centrifugal force separates the fine-grained mud from the coarse-grained sand.

From the mouth of the Elbe to the Port of Hamburg, several million tonnes of sediment are dredged every year to keep the port accessible for ships. Where we take the dredged material depends on the quality of the sediments. That's why we regularly take samples of it and analyse them very closely. Today, over 95 per cent of dredged material is contaminated to such a low level that it can be safely relocated in the Elbe or transported to the North Sea. However, if the contamination is too high, especially in the case of old deposits, we bring the dredged material ashore to the METHA - the harbour's washing machine. The abbreviation stands for "mechanical separation of harbour sediments". We have been treating Elbe sediments in this plant since 1993, making the tidal Elbe ever cleaner.

In the first step, the dredged material is sorted and classified. This is done, for example, in huge centrifugal systems, the hydrocyclones: The centrifuging process separates the coarse material from the fine material - the result is sand, fine sand and, after drying in huge presses, so-called METHA material. The latter consists of particles that are even smaller than fine sand.

Exterior view of the METHA large-scale dredged material treatment plant showing conveyor belts and walkways
80 kilometres of pipelines and 1,500 kilometres of cable are laid on the METHA site.
Interior view of the large-scale METHA dredged material treatment plant shows a large screening drum for separating coarse foreign matter
Wood, stones, scrap metal - the trommel screen sorts all the large components out of the mud.

In a sand washing plant, the sand is thoroughly cleaned and leaves, branches or pieces of wood are removed. The form of processing in the METHA makes ecological sense and opens up new areas of application: both the clean sand and the fine sand can be utilised as earthworks materials. The silt or METHA material is either used as a sealing material in silt landfills or is stored in an environmentally friendly manner - for example in the Feldhofe landfill in the Moorfleet district. It can also be used for dyke construction or the production of lightweight concrete, for example. 

Our METHA was the first large-scale plant of its kind in the world and can process up to 230,000 tonnes of dredged material per year. It provides continuous basic cleaning of the Elbe river.
 

Video contributions to our METHA:


Port is what we do video: The Port of Hamburg's washing machine - how the METHA works

Our harbour TV report explains the individual processing steps

The Sat1 editorial team visits our METHA

 

Aerial view of the METHA dredged material treatment plant in the middle of the green Elbe marsh near Finkenwerder

FAQ about METHA - the washing machine of the Port of Hamburg

The most important questions and answers at a glance.

 

The METHA is a specialised large-scale plant for the treatment of contaminated dredged material from the Port of Hamburg. Sediments are mechanically separated, cleaned and dewatered there.

 

 

In order for the harbour to remain permanently usable for ships, sediments must be removed regularly on a regular basis. In the case of higher levels of pollutants, removal from the water and treatment on land is necessary. Only then can the material be reused or disposed of.

 

 

No, the sediments are not actually cleaned in the METHA. However, by treating and separating the clean sand from the contaminated fine material, the amount is reduced and can then be safely deposited or used.

 

 

Whenever investigations show that the contamination of the sediments does not permit relocation in the Elbe or into the North Sea.

 

 

The material is sorted in several steps. The central elements are so-called hydrocyclones, which use centrifugal forces to separate fine and coarse components. The fine material is then thickened and dewatered in large presses. The sand can be used directly as a building material.

 

 

The dredged material is separated into sand and fine material (silt and clay). The clean sand can be used directly. The fine material is pressed and dewatered and then labelled as METHA material.

 

 

Large components are sorted out at an early stage using screening systems and disposed of separately.

 

 

Cleaner sand fractions are used in the earthworks and construction industry, mostly at the HPA's own dredged material landfills. Finer components can be used, for example, in landfill sealing, dyke construction or in special building materials. However, the majority of fine material contaminated with pollutants is disposed of safely.

 

 

Yes, the plant helps to remove pollutants from the sediment in a targeted manner and keep the Elbe and North Sea cleaner in the long term. It is also powered by green electricity and all wastewater is reused or treated very cleanly

 

 

The plant has been in operation since the early 1990s and was the only one of its kind in the world when it was commissioned.

 

 

Several hundred thousand tonnes of harbour sediment can be processed there every year.

 

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One hand holds a sample jar of mud up to the camera. A label from the Hamburg Port Authority (HPA) with the inscription "Ref 14-3_20" and the sample date "16/17/08/2014" can be seen on the jar. The Elbe can be seen in the background.
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