Sammendrag
NIVA has conducted operational monitoring of the Hemnefjord on behalf of Wacker Chemicals Norway AS. The monitoring programme was prepared in accordance with the Water Frame Directive and approved by the Norwegian Environmental Agency. The programme was designed based on the company’s discharges of contaminants to the Hemnefjord. Levels of polycyclic aromatic hydrocarbons (PAH), and metals were analysed in blue mussels from four stations and sediment samples from six stations. Four sediment samples were taken close to the smelting plant, and two sediment sample were taken outside Grøtvågen.
The concentrations of metals and PAHs in blue mussel were low, and no concentrations exceeded the EQS’s for the priority substances The blue mussel stations are therefore in “good chemical status”. One sediment station outside the landfill area was in “not good chemical status” because of because of a slight exceedance of EQS-value for one of the PAH-compounds. The sediment station outside the quay area is classified to “not good chemical status” due to concentrations of four PAH compounds exceeding the EQS-values. It was shown that the sediment in Grøtvågen is somewhat contaminated by PAH compounds. The sediment from two stations at Grøtvågen was classified to “moderate” and “poor” condition, according to the Norwegian Environmental Agency’s classification system. It cannot be ruled out that the sediment in Grøtvågen may be a source of PAH contamination, and might explain the PAH levels detected at station S1 in the monitoring in 2015.
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