Pre-study of ship wreck risk assessment and remediation

Report, 2007

In the Skagerrak there are 261 ship wrecks which have been identifi ed as potentially polluting wrecks. Twenty of these are located close to the Swedish coast, within the Västra Götaland County. The majority of the potentially polluting wrecks originate from the Second World War, hence many are heavily corroded and some are already leaking oil. In Sweden this problem has been discussed now and then since the mid seventies, yet there is no legislation regulating the liability for preventive actions to avoid future oil spills from the actual wrecks. This pre-study highlights potentially polluting wrecks in the Skagerrak, but the problem is present along the rest of the Swedish coastline. Therefore, there is a need for the establishment of a national database over recognized potentially polluting wrecks. Present salvage technology allows for offl oading the oil onboard the wrecks, but the remediation operation can be very expensive (about 20-250 million SEK per wreck). This cost has to be compared to the socioeconomic consequences occurring in case of a sudden leak of the corresponding amount of oil along the coast. To ensure that the environmental benefi ts of a remediation are economically justifi ed, it is of great importance to initially conduct a detailed wreck assessment which in addition to verifi cation of the amount and type of oil onboard, also ascertains that wreck stability will allow remediation. The cost of such an assessment ranges from 0.5-2 million SEK per ship wreck. To fi nance both ship wreck assessment and remediation of wrecks where no owner can be held responsible, establishment of a fund similar to that intended for remediation of contaminated land sites could be used. Additionally, the formation of a national competence centre to support the fund, gather knowledge in the fi eld of ship wreck assessment and remediation and coordinate actions is recommended.