Operational monitoring of the Husebybukta at Lista in 2019. Monitoring on behalf of Alcoa Lista.
- Year of publication
- 2020
- Contributors
- Sigurd Øxnevad, Dag Øystein Hjermann
Sigurd Øxnevad
Dag Øystein Hjermann
Summary
NIVA has conducted operational monitoring of Husebybukta on behalf of Alcoa Lista. 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 Husebybukta. Levels of polycyclic aromatic hydrocarbons (PAH), arsenic, lead, cadmium, copper, chromium, mercury, nickel and zinc were analysed in common limpets from five stations. Water samples were taken monthly in Husebybukta and analysed for lead and cadmium. Common limpets from Tjuvholmen and Haugestranda had concentrations of benzo(a)pyrene and fluoranthene (priority substances) that exceeded the EQS’s. Common limpets from Einarsneset also had concentration of fluoranthene that exceeded the EQS. Chemical status of these three stations is therefore classified as “not good”. For the other two stations there were no exceedances of EQS for any of the priority substances. Chemical status for stations Havik and Østhassel is therefore classified as “good”. Concentrations of lead and cadmium in seawater in Husebybukta exceeded AA-EQS (annual average EQS). Chemical status for this station is therefore classified as “not good”. The concentration of cadmium was lower than in 2018. Higher concentrations of lead and cadmium in water samples from Haugestranda than in the outlet water from Alcoa Lista indicate that another source is polluting the area with heavy metals. A significant upward trend was found for mercury in cod caught near Skågskjera at Lista. The concentration of mercury exceeded EQS for this priority substance. Low concentrations of other heavy metals were also found, but increasing concentrations are seen for the last 10 years. Concentration of PAH metabolites in cod bile was above the background assessment criterion. This is an indication of PAH exposure. A significant downward long-term trend was found for OH-pyrene in cod bile.