image: 464 hydrology-related pages of the Aclara Penco EIA, scored 0-3 per assessment stage.
Credit: Utrecht University Applied Data Science master's thesis (2026)
This June 2026, Chile’s first rare-earth mining project was unanimously approved by the Environmental Evaluation Commission (COEVA), despite ongoing community discontent and a 2022 vote that led to a 99% rejection of the mining plans. Two Utrecht University master's theses analyzed the roughly 8,900-page Environmental Impact Assessment (EIA) of the Aclara Resources (REE Uno SPA) mining project, including three rounds of public consultation. Both studies find the same structural pattern: the documents are strong on description, but thin where impacts on water should be identified, evaluated, and mitigated. Moreover, the public consultation process entirely omits or only superficially addresses 74-80% of raised concerns. This raises questions about the validity of approving a water-intense mining project in a water-stressed region.
The mining operation is planned in Penco-Lirquén, Biobío region, in a water-stressed region near a densely populated area and presents strong sustainability claims: no tailings, native tree-species reforestation, ‘harvesting’ instead of ‘extracting’ rare-earths, and no water drawn from local water bodies. On the other hand, community concerns range from radioactive contamination to biodiversity loss and reduction of freshwater discharge (groundwater) to a local estuary. The UU Applied Data Science master's theses used natural language processing — topic modelling combined with large language model (LLM) scoring — to examine, for the complete EIA documentation, how the assessment and the company's responses handled hydrology issues and community concerns.
The first study scored the 464 hydrology-related pages of the EIA against the seven standard, mandatory stages of a water impact assessment and found that significant evaluation — the stage that judges how serious an impact would be — is heavily underrepresented, only 4% of pages. Consideration of alternatives and mitigation represents only 2%. Where impacts are identified or mitigated, the content is mostly rated "present but vague": mentioned without data, units, or site-specific detail (Figure 1). The gap is starkest for individual topics (Figure 2). Water use and demand — the heart of the project's recirculation claim — receives 133 pages of description, more than any other topic, but not a single page identifying or evaluating impacts. Groundwater receives a detailed, high-quality baseline study but almost no evaluation.
The second study examined the consultation dialogue: three rounds in which citizens and agencies submitted 713 consolidated concerns (‘Icsara’) and the mining company responses (‘Adenda’). Across all three rounds, coverage was robustly stable: about 7% of concerns were not addressed at all, roughly two thirds were only partially addressed, and merely 20–26% were fully addressed (Figure 3). The scoring measures whether a concern was substantively engaged with, not whether the answer was correct.
Both studies are explicit about what the findings do and do not show. The patterns in the EIA are consistent with selective disclosure and attention deflection — two standard mechanisms described in the greenwashing literature (Marquis & Toffel, 2012). Neither study makes claims about whether environmental harm will occur, but what the analyses do provide is a reproducible, page-level map of where the EIA's evaluative coverage of water is thin or absent, and of which public concerns went unresolved — at a scale no manual review could match. As public scrutiny of the project continues in Chile, that map shows precisely where the assessment describes rather than evaluates.
"The race is on"
This is of concern to the European Union if it aims to uphold its commitments to safeguard justice and sustainability practices in strategic partnership with countries such as Chile. As the EU is increasingly targeting alternative rare-earth deposits to challenge Chinese market-dominance, it seeks to secure supplies of these materials for net-zero, defense, digitalization and aerospace industries. “The race is on” as EU-president Ursula von der Leyen famously recalled on various occasions. While policies like the Critical Raw Materials Act, aim so secure supplies of these materials and frame safeguards as ‘barriers’ to the swift implementation of extractive projects (Lagunas et al., forthcoming), this ongoing study demonstrates that key regulatory frameworks like EIAs should be bolstered to safeguard just and sustainable practices and ensure less irresponsible mining.
Notes for editors
The two studies are master's theses completed in 2026 in Utrecht University's Applied Data Science programme, supervised by Dr Lisa Bylinina and co-supervised by Prof. dr Maarten Kleinhans and Darko Lagunas: (1) "EIA Quality Assessment: A Computational Analysis of Hydrological Representation in the Aclara Penco EIA" and (2) "Rare earth mining in the Biobío region, Chile: How well were public concerns addressed?". Both analyzed the publicly available EIA record in Chile's Servicio de Evaluación Ambiental (SEIA) system. Code and materials are available on request. Figures redrawn from the theses. The research results are being prepared for peer-reviewed publication.