The situation in Norway concerning sediments/dredging Tore Lundestad, Port of Borg, Norway

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The situation in Norway concerning sediments/dredging

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Sediment Remediation in Norway - summary

  • Background.

  • Several fjords and harbors in Norway have suffered extensive contamination of trace metals as well as organic pollutants due to a long history of industrial activities. As a consequence fish and shellfish at a large number of sites contain levels of contaminants above what is considered recommendable for human consumption. To-day, the most important primary sources of pollutants have been cut and the remaining problem is contaminated soil and sediments.

  • Actions taken.

  • The Department of the Environment has launched a national remediation plan for contaminated marine sediments. A National Board was established in November 2003 to give advices to the Norwegian EPA regarding decision making, need of documentation, monitoring of effects, identification of gaps of knowledge, choice of remedial techniques etc.

  • Contaminated sediments.

  • Due to a low rate of natural sediment input to fjords and harbours in Norway, the bottom sediments contain high levels of trace metals and organic components in places where industrial and urban discharges of effluents took place . The primary constituents of concern are dioxins, PCBs, PAHs, TBT, brominated flame retardants and mercury, cadmium and lead. Experimental work has been performed to assess the mobility and bioavailability of contaminants in sediments (special volume in Mar. Pollut. Bull., vol.33, 1-6, 1996).

Sediment Remediation in Norway - summary

  • Sediment management.

  • During the last 10 years, mapping and monitoring of sediments along the Norwegian coastline have been executed. The levels measured have been compared with a set of national sediment quality criteria and in hot spot areas the levels of contaminants have also been measured in fish and shellfish. In areas where no local, primary point sources exist, and the level of contaminants in organisms exceed recommended levels with respect to human consumptions, actions plans are made to reduce or eliminate non-point sources (contaminated soil on land or contaminated bottom sediments). Each county is responsible for local action plans, but the work is coordinated by the Norwegian EPA.

  • Sediment remediation.

  • In Norway to-day few sediment remediation projects have been carried out. We are still in the planning stage. There is one full scale capping project carried out near a zinc plant (Odda) in 1992 and a few minor capping projects. Monitoring results suggest that the capping has been successful.

  • Our present recommendation is to avoid dredging and in stead use in situ capping with clean, sandy material. In areas where sediment removal is necessary, like in harbours and navigation channels, we have been considering dredging and underwater disposal in anoxic fjord basins, followed by capping. Experimental work clearly indicates that capping of dredged material in anoxic basins is environmentally acceptable and economically feasible.

The situation in Norway concerning sediments/dredging

Information about the Norwegian coast

  • The Norwegian coastline is about 2600 km

  • There are about 750 fishing ports in Norway

  • There are 56 commercial ports

  • There are more than 100 private port facilities related to industry activities

  • Lot of industry activities are located both in harbours and Fjords

  • Typical for a Fjord is the threshold in the entrance

Dredging works in Norway

  • The main dredging in Norway has been capital dredging.

  • The capital dredging is mainly rock blasting and solid sediments

  • There is very little sedimentation in fjords and harbours.

  • Due to that the environmental problems are huge.

What has been done in Norway the last years on investigations

  • Between 1992 and 1998 there has been carried out lot of investigations about sediments in ports and fjords.

  • More than 80 locations have been pointed out as priority areas

  • Most of the commercial ports have contaminations in the sediments. The main reason is the location in middle of the “city centre”

  • There is lot of contaminations in the fjords in areas with industry activities

  • The contaminations are result of 100 years of industrial activity

  • Most of the industry are gone

  • Port Authorities are sitting back with a huge problem created by others

  • The Norwegian EPA will in phase 1 give 13 Norwegian Port Authorities the responsibility for the remediation in their own harbour

Investigated areas along the coast

Who are going to pay for the remediation?

  • “The Polluter Pay” is the basic principal in these issues

  • Exciting industries are responsible for the sediment remediation related to their own activity

  • Lot of industries are not able to take the bill from the sediment remediation

  • The cost estimate is about 300 million Euro for the harbour basins and between 1 and 4 Billion Euro for the “rest”

  • The State have to take most of the cost if they want the sediment remediation to be done

  • As a result of the huge problem – The Department of Environment has established a National Board to give advices to the Norwegian EPA regarding decision making, need of documentation, monitoring of effects, identifications of gaps of knowledge, choice of remedial techniques etc.

The national action plan for sediment remediation in Norway

  • The National Board has started up following works:

    • Development of a tool for risk assessments
    • Development of a tool for cost/benefit analysis
    • Establishing goals for the remediation on a local, regional and national level
    • Effect of long distance transportation of contaminations by water and air compared with local and regional contaminations
    • A strategic plan to getting all involved to join the “remediation project”
    • Who are going to be the “owner” of these projects?

The national action plan for sediment remediation in Norway

  • The National Board has started up following works:

    • What is the gaps of knowledge and what is the critical knowledge of starting the remediation?
    • 5 pilot projects
      • Degradation of TBT
      • Using different geosystems as tubes, bags etc.
      • Sand capping
      • Cement stabilisation
      • Effect of strong current and tide water for transport of sediments

The national action plan

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