Challenges of old mining cities in the application of the proposed EU Soil Monitoring Law – Outokumpu, Finland, as an example

The city of Outokumpu in Eastern Finland occupies a Cu-Co-Zn mining region.  Mining and metallurgical activities began already in 1913. This area falls within a zone with naturally high concentrations of Ni, Cu, Co, and Zn in soil and bedrock. In addition, mining waste has been used in earthworks, especially in the construction of the city's streets.

In the summer of 2023, the European Parliament and Council proposed a Soil Monitoring Law, comparable to the earlier regulations established to protect air and water. The proposal mandates member states to address soil contamination. The European Union funded Horizon Europe project ISLANDR ‘Information-based Strategies for Land Remediation’ will provide data, tools, and methods to support the initiative. ISLANDR is a cross-disciplinary and multi-actor project and aims to promote the delivery of Green Deal objectives.

To provide real-world research context for different land use, climate and vegetation, seven test areas across Europe were chosen for a more detailed survey. Test areas were selected to characterize both point and diffuse sources of pollution, as well as by different soil pollution types.

The test area representing the brownfield mining areas is Outokumpu. Extractive wastes rich in sulphur, nickel, copper, zinc, cobalt, chromium, and other 'potentially toxic elements' (PTEs) were stored according to regulation which earlier was not as advanced as today. These wastes were also used for construction purposes, causing additional acidity and PTE load for the environment. Locally, elevated concentrations of PTEs have been observed in soil, groundwater, and surface waters.

Recommendations for regulation and remediation methods are compiled. Financial challenges, proposed solutions to improve the environmental status of the region, and opportunities for reusing or decontaminating degraded soils are discussed. Lessons learned in the historical Freiberg mining area in Germany will be utilized (Loukola-Ruskeeniemi et al., 2022: J. Haz. Mat. 424, 127677). The results from Outokumpu and Freiberg will be compared, for example, with the results of the EU MIREU project (Mining and Metallurgy Regions of EU MIREU GTK).