Vurdering av PCB-forurensning ved ubåtbunkeren i Laksevåg

Abstract

FFI has on assignment from Forsvarsbygg MIKU performed investigations to identify possible leakage of PCB from the old demolished docks at the submarine pen in Laksevåg, Bergen. The focus on this study has been to evaluate if there is any leakage of PCB to the marine environment, which can cause an environmental risk. Water from groundwater wells and seawater were sampled with the high volume water sampler developed by FFI. In addition SPMD were deployed in seawater just outside the demolished docks. To assess diffuse sources of PCB, samples of mud from sand traps and a culvert were analysed. It has not been possible to detect any leakage of PCB from the demolished docks. The probability is therefore very small for a leakage of PCB, which will cause a risk for the marine environment. FFI consider it therefore not necessary to initiate preventive measures at the old demolished docks. The concentration of PCB in mud from sand traps and the culvert was high. It is therefore recommended to remove the contaminated mud and establish procedures for routine removal of mud in order to reduce the risk for transport of contaminated mud to the marine environment. It is also recommended to evaluate if it is possible to investigate if there still are any local sources of PCB above ground at the submarine pen. The City of Bergen has to document any transport of PCB with surface water to the marine environment outside the submarine pen in Laksevåg.