Replacement Guide for Boundary Wall
The Perimeter Wall Replacement at the Wyckoff/Eagle Harbor Site is an active construction project, aimed at addressing site contamination and improving containment. This project, which began in early 2025, includes debris excavation, sorting, and the installation of a new perimeter wall designed to control contaminated materials and protect the surrounding environment.
Timeline and Current Status
As of August 11, 2025, debris excavation and sorting activities are anticipated to be completed within two weeks, indicating that the project is well advanced in its early phases. Construction of the perimeter wall commenced earlier in the year, with continuous progress expected throughout 2025.
Construction Methods
The project employs advanced construction techniques, although specific methods for the Wyckoff site perimeter wall are not exhaustively detailed. However, similar projects have used environmental permits for in-water work, deep drilled shafts, and testing methods like Sonic Integrity Testing and Thermal Integrity Profiling to ensure structural soundness. The perimeter wall likely incorporates steel and concrete elements designed to halt the migration of contaminants and includes in-situ solidification/stabilization (ISS) to immobilize hazardous waste in the soil.
ISS (In-Situ Solidification/Stabilization)
ISS is a remediation technology that mixes binding agents with contaminated soil to chemically stabilize or solidify pollutants, reducing their mobility and hazard. This process is common in Superfund cleanups to manage heavy metals or persistent toxic compounds safely onsite. While not explicitly detailed in the current data for Wyckoff/Eagle Harbor, ISS is frequently part of the remedy at sites with similar contamination profiles and likely plays a significant role in the perimeter wall construction and soil treatment at this site.
Community Impact
EPA oversight emphasizes safeguarding community health by controlling exposure risks and preventing contaminant migration via engineered barriers like the perimeter wall. The community reuse vision supported by past grants suggests redevelopment aspirations aligning with cleanup efforts, giving a positive framework for long-term community benefits. Construction has some nearby community impacts such as traffic disruption and odors from site disturbance, but these are managed under EPA supervision.
Additional Information
- A printable version of the fact sheet is available: Perimeter Wall Replacement at Wyckoff/Eagle Harbor Superfund Site (pdf) - February 2025.
- Noise: Construction will generally adhere to City of Bainbridge Island noise regulations, with contractors taking steps to reduce overall noise and the EPA performing daily perimeter noise monitoring.
- Roadways: The Creosote Place NE roadway and parking lot will be closed beginning in March 2025 due to an increased number of construction vehicles.
- Beach access: Portions of the beaches will be closed during certain stages of construction, with barricades preventing access to construction zones.
- Some construction activities may cause odors, and the EPA will perform daily perimeter air quality monitoring.
- An exterior marine-grade concrete armor wall will be constructed to protect the new wall from weathering.
- The existing sheet pile wall will be cut and removed once the new wall is complete.
- The construction is expected to take two years.
- ISS reduces the rate at which groundwater can move through the solidified contaminated soil, slowing the rate of leaching and limiting groundwater exposure to contaminated soil.
- EPA, the Army Corps of Engineers, and their contractors will take steps to minimize impacts during construction.
- Debris excavation will be conducted to remove old bulkheads during the construction.
- This basic chemical treatment with cement limits the ability of the creosote to migrate into the groundwater and marine environment.
- The Perimeter Wall Construction Closure Fact Sheet was originally published in February 2025.
- The innovative construction techniques used in the project, such as ISS (In-Situ Solidification/Stabilization), aim to halt the migration of contaminants, not only in water but also in land and soil.
- The Perimeter Wall, designed to control contaminated materials, not only protects the surrounding environment on land but also in air and water, particularly in marine environments.
- ISS, a common remediation technology in Superfund cleanups, is likely to be employed in the Perimeter Wall Replacement project, given the similarity in the contamination profiles at the Wyckoff/Eagle Harbor Site.
- The community around the site may experience temporary impacts like traffic disruptions, odors, and beach access restrictions during the construction period, but these impacts will be managed under EPA supervision.
