Impacts of Nuclear Waste on Fish

Impacts of the NWMO Nuclear Waste Repository on Fish and Aquatic Ecosystems

This report provides a forensic analysis of the potential impacts of the Nuclear Waste Management Organization (NWMO) Deep Geological Repository (DGR) on fish and aquatic ecosystems in the Revell Site area. The analysis is based on proponent submissions, public registry comments, and internal technical reviews.

Executive Summary

The proposed DGR project poses significant, long-term risks to fish and aquatic habitats in the Revell Lake and Wabigoon River watersheds. While the proponent asserts that mitigation measures will keep risks 'low,' the lack of site-specific, multi-year baseline data and the potential for cumulative industrial stressors suggest that the project could lead to localized extirpations or long-term degradation of aquatic health. The primary concerns involve groundwater-surface water interactions, the mobilization of existing contaminants, and the physical disruption of spawning and nursery habitats.

Detailed Analysis

The Revell Site is situated within a complex hydrological network. Our internal technical review [Analysis: 14.6] indicates that the proponent's reliance on 'inferred' fracture zones and limited borehole data (only five deep samples) creates a high degree of uncertainty regarding how groundwater—and potential contaminants—might migrate into the Mennin and Wabigoon river systems. The proponent's own baseline data [Ref: 14.8.1] acknowledges the presence of 55 fish species and critical spawning areas, yet the project description lacks a robust, site-specific impact model for these populations.

Evidence from Public Registry

Community members have expressed profound concern regarding the protection of the English River and Winnipeg River watersheds [Ref: 623, 607]. Commenters highlight that the project's location at the headwaters of major river systems poses a 'significant risk' to Canada's freshwater resources [Ref: 435]. Indigenous Nations, including the Grand Council Treaty #3, have emphasized that water is sacred and that the project fails to harmonize with traditional laws regarding land and water management [Ref: 705, 660].

Technical Deficiencies & Gaps

Our internal review identified several critical gaps in the proponent's environmental assessment:

• Inadequate Baseline: The reliance on eDNA metabarcoding without physical ground-truthing (netting/trapping) for species like the American Eel is scientifically insufficient [Analysis: 14.8.2].
• Contaminant Mobilization: The proponent claims the rock is 'non-acid generating' but fails to model how physical blasting and sediment disturbance might mobilize existing mercury and heavy metals already present in the watershed [Analysis: 14.4.1].
• Hydrological Uncertainty: The 'low groundwater flow' assumption is based on limited data, failing to account for the potential for fracture-controlled flow paths that could bypass engineered barriers [Analysis: 14.6.1].

Recommendations & Mandates

We strongly recommend that the proponent conduct a multi-year, site-specific field validation program for all fish and aquatic SAR identified in the baseline. This must include physical sampling to verify eDNA results. Furthermore, we strongly recommend the establishment of a 'Joint Environmental Oversight Committee' with the Wabigoon Lake Ojibway Nation (WLON) to co-develop water quality thresholds. This committee must have the authority to trigger 'stop-work' orders if monitoring detects deviations from the baseline that threaten aquatic health.

Finally, the proponent strongly recommends the development of a 'Cumulative Effects Management Plan' that explicitly models the interaction between repository construction and existing industrial stressors (forestry/mining) in the region to ensure the project does not become the 'tipping point' for regional aquatic biodiversity loss.

Conclusion

The risk to fish and aquatic ecosystems is currently underestimated due to data gaps and the proponent's reliance on generic mitigation strategies. A precautionary approach, characterized by independent monitoring and site-specific validation, is the only path forward to ensure the protection of these vital natural resources.