- July 21, 2026
How Permafrost Degradation Impacts Water Quality
Permafrost degradation is the thawing of ground previously frozen below 0 °C for more than two consecutive years (permafrost). Due to its potential to alter baseline groundwater conditions, influence contaminant mobility, and complicate environmental management and regulatory compliance, permafrost degradation is emerging as a critical challenge for mine operations located in subarctic and Arctic regions.
Recently, a research article by Skierszkan et al. (2026) highlighted that stream chemistry and ecosystem function are being impacted by rapid sulfide-mineral oxidation in permafrost-underlain headwater catchments of two large (sub)Arctic rivers in North America. In this month’s Conversation on Closure, we’re diving deeper into the impacts of thawing permafrost to site-wide water quality and what mine sites located in permafrost-extent regions can do to address potential risks for acid mobilization and minimize potential water quality impacts.
What are the Impacts of Permafrost Degradation?
Permafrost acts as a natural barrier that restricts groundwater flow and limits water–rock interaction. As it thaws, this permafrost barrier weakens, allowing increased groundwater circulation through previously frozen sediments.
For mine operations, these evolving flow regimes may complicate predictions of groundwater movement, affecting pit dewatering strategies, tailings storage design, background contributions from permafrost degradation, and long-term water management plans.
A key concern associated with permafrost degradation is the mobilization of naturally occurring metal(loid)s, including uranium (U), arsenic (As), cobalt (Co), and nickel (Ni). Elevated concentrations of these metal(loid)s and similar elements can complicate the differentiation between baseline conditions and operational impacts. This complexity stems from potential changes in groundwater hydrology, increasing interactions between surface and subsurface systems, and enabling new pathways for solute transport.
As a result, environmental baseline studies conducted before mine development may no longer be representative over the life of a project. Climate-driven changes can shift groundwater chemistry independently of mining activity. The potential impacts of permafrost degradation include:
- Baseline variability: Natural rises in contaminant levels could be misinterpreted as mining-related impacts.
- Regulatory risk: Compliance frameworks may need to account for evolving natural conditions.
- Monitoring requirements: More frequent and adaptive monitoring programs may be required to capture evolving trends.
Addressing the Geochemistry
Figure 1 shows a global map of permafrost extent. The typical classification of permafrost zones includes continuous permafrost (occurring beneath 90-100% of the landscape), discontinuous permafrost (50-90%), sporadic permafrost (10-50%), isolated permafrost (>10%), and subsea permafrost (International Permafrost Association, 2021; Way, 2018).
Figure 1. Global map of permafrost extent. Adapted from “Circum-Arctic Map of Permafrost and Ground-Ice Conditions,” by Brown, J., O. Ferrians, J. A. Heginbottom, and E. Melnikov, 2002, NASA National Snow and Ice Data Center Distributed Active Archive Center.
In a study of natural acid and metalliferous drainage (AMD) in Yukon’s continuous permafrost zone, seepage from the base of a thaw slump exhibited significantly poor water quality, exceeding Canada’s aquatic-life water guidelines (Skierszkan et al., 2025). Unexpected deterioration in water quality – whether resulting from natural AMD due to permafrost degradation or from mining activities – can become a substantial liability for mine sites operating in permafrost zones.
For example, permafrost degradation at a northern zinc mine site released natural AMD into downstream waters, requiring a costly diversion of treated wastewater to the site’s main pit in order to maintain compliance with discharge permits. This situation highlights the challenges associated with managing AMD on a mine site under thawing permafrost conditions (Skierszkan et al., 2025).
Identifying and addressing AMD risks from thawing permafrost requires mining companies to consider:
- expanding hydrogeological and geochemical monitoring networks to detect early changes to water quality;
- designing flexible water management systems capable of managing variable contaminant loads; and
- collaborating with subject matter experts to improve understanding of thaw-driven processes and contaminant release mechanisms.
Integrating models of groundwater flow, geochemical evolution, and permafrost probability can help inform the hydrogeological impacts of permafrost degradation (Jin et al., 2022; Skierszkan et al., 2025). Regional- and local-scale permafrost probability models, in particular, can help identify catchment-scale vulnerability to hydrological and (bio)geochemical changes associated with thaw, especially in discontinuous and sporadic permafrost zones where distribution is heterogeneous and thaw rates are fast (Skierszkan et al., 2025).
Geotechnical Considerations for Permafrost Conditions
As soil temperature in permafrost rises, the soil begins to lose resistance due to an increasing volume of meltwater (Dourado et al., 2024). The release of meltwater can weaken the bond between silt and clay, lead to ground settlement from soil compaction, and increase porewater pressure, contributing to potential slope instability (Memis et al., 2025; Liew et al., 2022).
Reduced soil-bearing capacity and geotechnical shear strength from permafrost degradation can affect the integrity of existing and planned mine infrastructure, including any deep foundations, roads, railway embankments, and water management systems (Dourado et al., 2024; Liew et al., 2022). In impacted regions, mine site operators need to consider permafrost degradation as a credible failure mechanism and consider geotechnical designs and construction methods to support higher loads capable of withstanding frost action forces (Dourado et al., 2024).
Reduced soil-bearing capacity and geotechnical shear strength from permafrost degradation can affect the integrity of existing and planned mine infrastructure, including any deep foundations, roads, railway embankments, and water management systems (Dourado et al., 2024). In impacted regions, mine site operators need to consider permafrost degradation as a credible failure mechanism and consider geotechnical designs and construction methods to support higher loads capable of withstanding frost action forces (Dourado et al., 2024).
Mine infrastructure designs for permafrost regions should account for evolving climatic conditions, changing soil temperatures, and potential impacts on the effective strength of permafrost soils, rather than assuming that frozen grounds will remain stable throughout the life of mine (Dourado et al., 2024). Integrating climate change risk studies and identifying credible failure mechanisms related to settlement and stability into mine and tailings designs can help sites evaluate how landform designs are expected to perform under freeze-thaw cycles and over the long term.
Okane’s Approach
At Okane, we have specialized experience in designing, testing, and monitoring mine waste and closure systems in Arctic and sub-Arctic climates. We are lead authors of the Mine Environment Neutral Drainage (MEND) Cold Regions Cover System Design Technical Guidance Document and work with a range of clients operating in permafrost regions. Our interdisciplinary, risk-based approach integrates geochemical, geotechnical, and mine water quality considerations to support practical, informed design and construction decisions across the mine lifecycle.
Okane develops site-specific climate change databases using statistically downscaled General Circulation Model data and leverages our knowledge in Shared Socio-economic Pathways to evaluate climate model outputs (both probability and consequence) at the regional and site-specific level. We also align both historical and site-specific climate change data to determine how landforms will perform and how site and landform water balances are influenced under changing climatic scenarios.
We can also conduct kinetic tests, including Advanced Customizable Leach Columns (ACLCs), to evaluate how permafrost materials behave under thaw conditions. These results can be integrated into numerical modelling tools to generate source terms and site-wide water quality models, quantifying total contaminant load from permafrost into the surface water.
For example, in Yukon, Canada, Okane helped one of our clients better understand closure risks related to permafrost. Our team conducted a comprehensive review of existing field data and developed inputs for one-dimensional thermal modelling. We applied two climate change scenarios to evaluate thermal response across several one-dimensional profiles, representing disturbed, remediated, and undisturbed conditions. We also completed two targeted sensitivity analyses to evaluate surface ponding and vegetation influence. The modelling results provided an enhanced understanding of thaw trends associated with a changing climate, as well as the influence of existing permafrost conditions and material properties on degradation with time. Our client subsequently coupled our permafrost modelling results with their groundwater flow model to assess project risks and inform remediation strategies as part of the regulatory assessment process.
Our team also plans and conducts field investigations and instrumentation and monitoring programs to support design development and performance management. Field investigations can include test pitting and/or drilling (e.g., auger, coring, or sonic) to assess foundation conditions in support of landform designs. Installing instrumentation such as slope inclinometers and vibrating wire piezometers, supported by visual inspections, is used to assess conditions in structures that are already constructed.
Our integrated approach supports practical, tailored mine and closure designs that identify risks and manage the potential impacts of permafrost degradation. Connect with us at info@okaneconsultants.com to learn more.
References
Dourado, J., Deng, L., Chen, Y., & Chui, Y.-H. (2024). Foundations in permafrost of northern Canada: Review of geotechnical considerations in current practice and design examples. Geotechnics, 4(1), 285–308. https://doi.org/10.3390/geotechnics4010015
Indigenous Peoples Atlas of Canada. (n.d.). Tundra and permafrost. https://indigenouspeoplesatlasofcanada.ca/article/tundra-and-permafrost/
Jin, H., Huang, Y., Bense, V. F., Ma, Q., Marchenko, S. S., Shepelev, V. V., Hu, Y., Liang, S., Spektor, V. V., & Li, X. (2022). Permafrost degradation and its hydrogeological impacts. Water, 14(3), 372. https://doi.org/10.3390/w14030372
Liew, M., Ji, X., Xiao, M., Farquharson, L., Nicolsky, D., Romanovsky, V., Bray, M., Zhang, X., & McComb, C. (2022). Synthesis of physical processes of permafrost degradation and geophysical and geomechanical properties of permafrost. Cold Regions Science and Technology, 198. https://www.sciencedirect.com/science/article/pii/S0165232X22000416
Memiş, M., Keskin, I., Demir, S., & Memiş, S. (2025). Machine learning-based prediction of permafrost degradation and its implications on geotechnical infrastructure: A comprehensive review. AI in Civil Engineering, 4(28). https://doi.org/10.1007/s43503-025-00080-8
Skierszkan, E. K., Dockrey, J. W., & Lindsay, M. B. J. (2025). Metal mobilization from thawing permafrost is an emergent risk to water resources. ACS ES&T Water, 5(1), 20–32. https://doi.org/10.1021/acsestwater.4c00789
Skierszkan, E. K., Szeitz, A. J., Lindsay, M. B. J., & Carey, S. K. (2026). Abrupt stream acidification and metal mobilization from permafrost degradation. Science, 392(6800), 863–867. https://doi.org/10.1126/science.aea2898
The Permafrost Association. (n.d.). What is permafrost? https://www.permafrost.org/what-is-permafrost/