Monitoring of heavy metal contamination at the Norwegian Armed Forces demolition facility for munitions in Lærdal municipality – results from 2021

In accordance with an agreement with the Norwegian Defence Logistics Organization (FLO), the Norwegian Defence Research Establishment (FFI) carries out chemical analysis and assessment of soil and water samples taken at the Armed Forces demolition facility for munitions in Lærdal municipality. An annual monitoring is done in order to document the degree of metal pollution in the two areas where demolition are carried out. In this report, the results from the monitoring of heavy metal pollution in 2021 are presented. This work supports the Norwegian Defense Sector's climate and environmental strategy’s goal of having an overview of sources of pollution and ensuring that pollution of water and soil is monitored and minimized. In Øyradalen southeast of Lærdal center, the Norwegian Armed Forces has a demolition facility where munitions are demolished by open-air detonation. In addition to the facility in Øyradalen, a destruction facility for small arms munitions and propellant is localized in Tønjumdalen. The destruction of such munitions takes place in an incinerator connected to a treatment plant. In 2008 FFI recommended that this area should be included in the monitoring program. The concentrations of copper in the demolition area in Øyradalen were higher than at the reference station in the valley. The mean concentration of copper in the demolition area was 575 mg/kg in 2021. This concentration was a slightly higher than the concentration measured in 2020 (461 mg/kg). Zinc and lead levels were also above background levels, while the concentrations of other heavy metals were equivalent to background levels. It is unlikely that the grazing animals at the demolition area is at risk for poisoning, but due to locally high copper concentrations, it cannot be excluded. In the river Nivla, which runs through the demolition area, the concentration of copper and lead did not exceed the limit values for toxic effects (7.8 μg Cu/L and 1.2 μg Pb/L) in any of the sampling points. Based on measured concentrations in Nivla in 2021, effects on aquatic organisms is negligible. The concentrations of lead in soil near the destruction facility in Tønjumdalen were above background levels, while the concentrations of other heavy metals were comparable with the background levels. The lead concentration in the soil in 2021 was on the same level as previous years. Still, the contamination level in Tønjumdalen was within the national limits for recreational areas, and no risk for health or grazing animals is expected. The concentration of lead in the river Kuvella in Tønjumdalen were above the limit for toxic effects of aquatic organisms in freshwater (AA-EQS) in one sample, and effects on aquatic organisms cannot be excluded. Based on the occurrence of metals in soil and water samples from Øyradalen and Tønjumdalen in Lærdal, the risk to humans and local fauna is low, but cannot be excluded. FFI therefore recommends that the areas are not actively used as grazing areas for animals and that the areas are still monitored.