Management and handling of contaminated sediments in the Netherlands
Type:
Presented during:
WODCON XVII: "Dredging in a Sensitive Environment" - 2004, Hamburg, Germany
Authors:
H. P. Laboyrie, A.L. Hakstege
Abstract: In order to maintain shipping routes and water discharge, large volumes of sediments have to be dredged from the Dutch waterways each year. Dredging is also done for environmental reasons (remediation). Each year approximately 30 million m3 of dredged material has to be removed. The main cause of the problem of dredged material is its contamination.
Following the Dutch environmental policy the order of preference of destinations for dredged material is: relocation, direct reuse, and treatment for beneficial use and at the end disposal. The main part of the dredged material is clean or lightly polluted and can be relocated at sea and on land. However, less than half of the dredged fresh-water material can be relocated because of higher contamination levels and lack of space along the banks of the waterways.
There are two options for dredged material that is too contaminated for relocation: treatment for beneficial use or disposal. Until now dredged material has been treated and re-used on a small scale only, because of higher costs of treatment compared to disposal and the lack of markets for the products of treatment. Dutch policy now aims at enlarging the amount of contaminated dredged material to be treated and re-used in order to reduce disposal and to produce construction materials.
Treatment of all contaminated dredged material is not feasible, which means that confined disposal will remain an important solution. In order to have sufficient disposal capacity for the future new sub-aquatic confined disposal sites in combination with treatment facilities are in preparation.
This paper gives an overview of the management and handling of contaminated sediments in the Netherlands. It describes the present situation and developments in policy, legislation, remediation, confined disposal and treatment. Reference is made to other congress papers for more detailed information on these issues.
Keywords: contaminated sediments, dredged material management, remediation, confined disposal, treatment, relocation