Environment – posters

Presentations are:

Flushed and Frustrated: The Uphill Battle of Sediment Discharge at Hydropower Dams, presented by Kyle Gustafson, Anchor QEA

Innovating for Sustainability: Chelan County PUD’s Oil-Free Journey, presented by John Sagerser and George Velazquez, Chelan County PUD

Details about each presentation and the speakers are below:

Flushed and Frustrated: The Uphill Battle of Sediment Discharge at Hydropower Dams
Presented by Kyle Gustafson, Anchor QEA

Sediment Flushing at Hydropower Installations-Why It Matters:
Reservoir sedimentation reduces storage capacity, affects energy production, and degrades infrastructure. While flushing is a viable and cost-effective sediment management strategy, it faces complex hurdles, particularly concerning downstream water quality, habitat impacts, and regulatory approvals.

Regional Differences:
Permitting requirements for sediment flushing vary across States and USACE districts, with differing interpretations of the Clean Water Act and other pivotal regulations. Some regions have approved flushing under maintenance exemptions, while others require full environmental reviews. Differences in sediment classification—whether seen as a pollutant or a resource—also affect approval timelines.

Regulatory Considerations and Hurdles:
Permitting challenges include environmental reviews, water quality standards, endangered species protections, and stakeholder opposition. Turbidity limits often conflict with the reality of flushing events, requiring adaptive strategies such as controlled releases and sediment trapping. Regulatory agencies may demand mitigation plans to offset potential impacts.

Lessons from Past Flushing Events:
This presentation will include several case studies where sediment flushing was performed, including a discussion of what was required for regulatory approvals, as well as for projects that have hit major regulatory roadblocks.

Navigating the Process:
Early regulator engagement and coordination, as well as construction pre-design investigation, and phased pilot programs improve the chances of successful permitting. Collaboration with stakeholders—including state and federal agencies and local environmental groups—can help to proactively mitigate project opposition.

Key Takeaways:
Sediment flushing can provide a cost-effective sediment management strategy, but obtaining regulatory approval can be challenging and daunting and can lead to significant project delays when improperly managed. Success depends on proactive planning, data-driven decision-making, and stakeholder engagement to balance operational needs with environmental compliance.

Innovating for Sustainability: Chelan County PUD’s Oil-Free Journey
Presented by John Sagerser and George Velazquez, Chelan County PUD

1. Financial / Environmental Justification – Routine trunnion seal leaks were undetectable leaving oil sheens in the tailrace at both Rocky Reach and Rock Island. This is not consistent with Chelan County PUD value of Stewardship.
2. Design and Implementation Considerations – “New” technology in North America with design life less than traditional oil-filled hubs lead to collaborative contracting and design processes. Multiple innovative solutions minimize risk of premature failure, dependence one technology, and is consistent with our value of Operational Excellence.
3. Potential Impacts to Operations and Maintenance – New systems, products, monitoring regimes and other challenges in implementing the new technology.
4. Operational Results to Date – Testing, commissioning, and operational results for three (3) oil-free hub units put in service in Q2, Q3, and Q4 2025.

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