Environmental impact assessment for Siilinjärvi mine expansion

Yara is planning to expand operations in Siilinjärvi, Finland, which is the location of the only phosphate mine in the EU – a recognised critical raw material. Expansion would enable continued operations beyond 2035, when the current permit period ends. The proposed expansion would allow mining activities to continue into the 2060s, providing both access to new ore reserves and additional capacity for waste rock and tailings disposal.

Ramboll supported this process by delivering a comprehensive environmental impact assessment (EIA), including the EIA programme and the final assessment report. Our work evaluated four implementation options, including the so-called zero option, assessing the consequences if the proposed project was not implemented. This provided a structured basis for decision-making and future permitting.

Supporting informed decision-making and stakeholder engagement

The EIA process generated a detailed understanding of environmental and social impacts, supporting both regulatory requirements and wider stakeholder dialogue. Ramboll combined technical studies, impact modelling, and nature assessments with stakeholder surveys, authority engagement, and community consultation, to ensure a robust and transparent process.

Comprehensive nature surveys were carried out across all expansion options, including habitat type and vegetation surveys as well as surveys of breeding and migratory birds, flying squirrel, moor frog, bats, and dragonflies. The findings provided important input to the impact assessment and have subsequently been supplemented to support further project planning.

As part of the EIA, Ramboll also prepared a conceptual mine closure plan for each expansion option. This assessed the effectiveness of potential closure measures, identified environmental risks, and highlighted further studies required to support future decision-making and permitting.

Visualisations from multiple viewpoints were also developed to assess potential landscape impacts and help stakeholders understand how the mine expansion could appear in the future. Building on these visualisations, Ramboll created an interactive 360° virtual tour, allowing users to explore the project from different viewpoints.

To further enhance accessibility, we used Ramboll’s Digi-EIA service to summarise complex assessment results and communicate them clearly to the public. The findings were presented at public events and shared with authorities, the project monitoring group, and the Siilinjärvi municipal council.

Enabling future planning and long-term value

The results of the EIA provide a strong foundation for the next stages of the project, including detailed planning and the upcoming permitting processes. Following the conclusion of the EIA procedure, further project development is expected to continue, with the permitting process anticipated to start between 2025 and 2028.

Beyond regulatory compliance, the project has broader regional and strategic significance. Continued mining operations will help sustain local employment and tax revenues, while supporting the long-term attractiveness of the area by preserving a large employer for years to come. In addition, the Siilinjärvi mine plays a key role in Europe’s security of supply, as it is the only phosphate mine in the EU and a source of a recognised critical raw material.