 | Tuesday, November 4 Enhancing Pump and Treat Operations at Hanford: Performance-Based Management Strategies and Remedy OptimizationPump-and-treat (P&T) systems are among the most commonly used groundwater remedies for hydraulic containment and treatment of contaminated groundwater. While P&T operations are highly effective for initial bulk containment and treatment, maintaining their performance throughout the lifetime of the remedy has been identified as a challenge at many sites. This case study focuses on the Hanford Site’s 200 West P&T remedy, which has been operating since 2012, and the Central Plateau groundwater remedy challenges. This case study presents a range of efforts for optimizing the system with respect to groundwater plumes and remedy performance, facility and field operations, and long-term planning to achieve cleanup goals. |
 | Wednesday, November 5 International Approaches to Discrete Aquifer Zone CharacterizationMany complex sites have a complicated geologic setting consisting of multiple aquifer and aquitard layers with varying hydrologic and geochemical properties and contaminant distributions. Adequate characterization of these conditions is critical to developing accurate and robust conceptual site models, supporting remedy design and the ability to monitor changing conditions and remedy effectiveness, including post-closure validation monitoring. Groundwater wells installed to characterize and/or monitor the hydraulic head and spatial distribution of contamination in aquifers can be grossly divided into two types: (1) wells that are open to the entire aquifer sequence or a significant portion of it, including long-screened wells or, in bedrock aquifers, open boreholes, and (2) wells that use multilevel sampling or completion technologies (e.g., packer systems, well liners, and/or multilevel well completions) to vertically isolate targeted portions of the aquifer including aquitard layers, if appropriate. These options present tradeoffs in terms of cost, data resolution, and technical constraints, and the benefits of each approach need to be considered in terms of the site geology, monitoring objectives, and site conceptualization. Through a series of international examples, alongside input from site operators and regulators, this case study will examine different approaches to discrete aquifer zone characterization. Collectively, these examples will help provide the basis for future guidance on identifying appropriate groundwater characterization and monitoring approaches in the context of site conditions, remediation objectives, and business case considerations (e.g., cost/benefit analyses, infrastructure requirements, safety considerations, etc.). |
 | Thursday, November 6 Remediation, Sustainability, and Reconciliation: The Port Hope Area Initiative as a Framework for Long-Term Environmental StewardshipThe Port Hope Area Initiative (PHAI), situated in the Municipality of Port Hope, Ontario, represents Canada’s largest low-level radioactive waste environmental remediation project. As a result of radium and uranium refining operations dating back to the 1930s, this site contains widespread contamination in residential, industrial, and municipal lands. While the cleanup was initiated at the request of the community to address the historical legacy and associated stigma of nuclear industry operations, community perspectives have evolved to now emphasize finding a balance between the removal of legacy waste and maintaining the environmental and socioeconomic integrity of the community. This case study examines the PHAI as a model for integrated environmental stewardship, with a specific focus on three interrelated dimensions: effective remediation of legacy waste, long-term sustainability planning, and meaningful engagement with Indigenous nations and local stakeholders. Key areas of focus include stakeholder consultation practices, environmental monitoring and risk management strategies, and the incorporation of Indigenous perspectives in governance and planning processes. Special attention is given to how the PHAI balances regulatory compliance with broader goals of reconciliation, transparency, and public trust. |