The potential environmental impact of acidifying or toxic elements in the bedrock has become a major concern for handling aggregates within construction projects.
A general lack of knowledge about the mineral chemistry of the bedrock, and its reactivity when exposed to water and air, challenge exploitation of the bedrock and effective recycling of rock masses in the circular economy. As a first step to reduce this lack of knowledge this study has investigated where, and in what minerals, elements hazardous to health and the environment occur in an arsenic rich bedrock in the Arlanda-Rosersberg area, north of Stockholm with the aim to find a time- and cost-efficient methodology for identification of potentially contaminating rock materials in construction projects to be applied early in the planning process.
One of the findings is that a close correlation between enrichments of arsenic in the bedrock and arsenic contamination of the groundwater confirm that the geochemistry of the groundwater can be a powerful predictive tool for the recognition of high-arsenic bedrock domains. In addition, handheld X-Ray fluorescence measurements at outcrops in the field turned out to be an effective tool for reconnaissance mapping of arsenic enrichments in the bedrock.
The main participants in the study were Per Nysten and Mattias Göransson (SGU), Jenny Andersson (SGU and NRM), Paul Evins (WSP), and Iwona Klonowska and Daniel Buczko (Uppsala University); also a master’s thesis (Skoog 2022) and a bachelor’s thesis (Nilsson 2024), both at Uppsala University, were carried out in connection with the study.
The study and the associated investigations were funded by BeFo, the Swedish Environmental Protection Agency, the Geological Survey of Sweden (SGU), and the Swedish Museum of Natural History (NRM). The engagement from a reference group consisting of 18 actors, including representatives from the academia, government expert authorities, supervisory authorities, consultants, and industry is acknowledged.
Stockholm
Patrik Vidstrand
