Dredging sludge generated in the Netherlands in 2002-2011
Development in the generation of dredging sludge in 2002-2011.
The total amount of dredging sludge generated in the period 2002-2011 will be almost 400 million m3. Approximately half is freshwater sludge; the other half is saltwater sludge.
Approximately 75 million m3 - almost 40% - of the freshwater sludge is severely contaminated (categories 3 and 4). Twelve million m3 of the saltwater sludge is severely contaminated (5%); most of it by far is mildly contaminated.
The amounts of sludge generated vary widely depending on the province. The largest amounts come from the west, centre and north of the country: broadly speaking, the parts of the Netherlands located in the river basins of the Rhine and the Maas and the fen peat areas.
Developments in the supply of dredging sludge in recent years
Approximately 30 to 35 million m3 of sludge a year has been dredged for the maintenance of Dutch waters in recent years. Roughly 75% comes from salt waters, namely seaports and fairways leading to these ports. The remaining 25% comes from fresh waters, mainly the regionally managed waters.
Dredging sludge quality categories.
| Type of dredging sludge | Concentration level | Processing |
| Category 0 | Concentration < target value | Free distribution (if distribution possible) |
| Category 1 | Concentration < limit value | Free distribution (if distribution possible) |
| Category 2 | Concentration < test value | Free distribution (if distribution possible) |
| Category 3 | Concentration < intervention value | Processing or landfill |
| Category 4 | Concentration > intervention value | Processing or landfill |
Policy
The table above sets out the policy for dealing with dredging sludge. Mildly contaminated dredging sludge (categories 0 - 2) may be freely distributed (if distribution is possible); severely contaminated dredging sludge (categories 3 and 4) must be processed or sent to landfill. The objective is to process, or where possible recover, at least 20% of the sludge that does not qualify for distribution.
References
- AKWA and Provinciale Werkgroepen (2001). Basisdocument Tienjarenscenario Waterbodems. Bagger in Beeld. Advies en Kenniscentrum Waterbodems, AKWA report no. 01.014, Utrecht.
- CIW (2002). Water in beeld 2002. Voortgangsrapportage over het Waterbeheer in Nederland. Commissie Integraal Waterbeheer, The Hague.
- V&W (1999). Fourth Water Management Policy Document. Ministry of Transport and Public Works, The Hague.
