DUMPING ON STOCKHOLMARNA A GEOCHEMICAL, HYDROGEOLOGICAL, SEDIMENTOLOGICAL AND HISTORICAL EXAMINATION OF A MID-1900S DUMPSITE

Abstract

This study examines an early 1900s dumpsite in the estuary of the Nordre Älv river, which is currently located within a nature reserve. It investigates several factors, including the degree of contamination of the dumped masses, to what extent the surrounding estuary is contaminated by the dumpsite, and which measures might be taken to reduce the risk of future damage to the estuary. PXRF analysis of fine material extracted from sediment samples is used to determine comparative contaminant concentrations in said samples. The investigated contaminants are the heavy metals chromium, copper, zinc, lead, mercury and arsenic. The study attempts to substanitate oral records of the active years of the dumpsite through basic historical and archaeological research, and broadly agrees with the 1925 – 1942 active dates proposed by previous researchers. These dates have been refined, with a definite end in October 1941. The study finds that the dumpsite is significantly contaminated in heavy metals, with regards to both its soil and groundwater. The river sediment surrounding the dumpsite is found to be contaminated by it, but not symmetrically, with the majority of contamination seemingly occurring through mechanical erosion of the dumpsite into the bay to the southwest. Erosion control of the bank facing this bay is therefore suggested as a means of significantly limiting further contamination. The dumpsite is known to be used for intermittent sheep farming and has been used in the past for potato cultivation. Based on the heavy metal concentrations in the soil and groundwater of the dumpsite, neither of these activities are deemed suitable, and I strongly suggest that all agriculture and animal husbandry on the dumpsite cease immediately. Among livestock, sheep are especially prone to consuming soil along with vegetation, and it is my opinion that any products of the sheep raised on the dumpsite should be treated as suspect. At minimum, an investigation into the heavy metal contents of meat, bone, leather and milk is suggested prior to human consumption.