Undersøkelse av ammunisjonsrelatert forurensing i Hengsvann skyte- og øvingsfelt

Hengsvann firing range consists of an area of 34 km2 and is located in Kongsberg and Notodden municipality. The range is used all year around and is a popular range for training. The range is used both for small arms ammunition and large caliber ammunition. The large caliber ammunition used is mainly mortar ammunition, but armor-piercing ammunition is also used to a significant extent. The range has been in active use since the late 1950's. The Norwegian Defence Research Establishment (FFI) has in collaboration with the Norwegian Defence Estates Agency (Forsvarsbygg) carried out an assessment of munitions-related contamination in the range. The assessment was focused on clarifying the contamination of white phosphorus in the target areas for smoke ammunition, and whether it can be traced residues of explosives and heavy metals in fish caught in Hengsvannet. Sediment and water in Hengsvannet is also sampled for determination of munitions-related contamination. Based on the results of the assessment the risk for human and environment is evaluated. The study is a follow-up of the investigations made in 2009 by Akvaplan-niva on assignment from Forsvarsbygg. The investigations of the extent and distribution of munitions-related contamination in Hengsvann firing range, has shown that there are traces of munitions-related contaminants in water, sediment and fish. The levels are however so low that they are considered insignificant in terms of risk to humans. The Assessment includes risk as a result of ingestion of soil, sediment, water and fish. It was not possible to find craters from phosphorus grenades in the target area. The condition index for fish is normal, and no abnormal conditions were observed during the dissection of the fish.