Project: Sports Fields
Integrated Cleanup & Redevelopment
Sports Fields & Office Building
CRETE principals led the investigation and cleanup of this brownfield redevelopment project at a former wood-treating site on Lake Washington. CRETE principals completed the RI/FS, Cleanup Action Plan, Consent Decree, Engineering Design Report, and design plans and specification for cleanup of the property. Remediation on the property consisted of:
- In situ soil mixing of source area soil and NAPLs with cement and bentonite
- Sediment removal from a cove and restoration of a forested wetland
- Soil capping that was fully integrated with site redevelopment
CRETE principals also worked with the design team to:
- Relocate a Class 2 salmon-bearing stream
- Develop a site-wide stormwater management program
CRETE principals provided construction oversight, and permitted and oversaw construction stormwater management that included carbon dioxide and chitosan treatment.
Work Performed
- Property transaction due diligence
- Regulatory negotiations - MTCA
- Upland and sediment RI/FS
- Permitting - in-water cleanup, wetlands, stream relocation, construction stormwater, Metro discharge
- Sediment cleanup
- Wetland restoration
- Shoreline site cleanup and development coordination
- Methane mitigation systems
- Construction plans and specifications
- Construction stormwater treatment
- Construction oversight
- Stormwater system design
Value Added
- Negotiated that RCRA F-waste listings did not apply to soil and groundwater
- Used physical criteria to minimize the volume of K001 listed waste
- Negotiated a flexible cleanup schedule to allow coordination with development
- Created a menu of environmental cap designs to allow multiple site development scenarios
- Developed the CAP to allow grading and reuse of contaminated soil on site
- Designed in situ soil mixing of source soil and NAPLs to contain source material due to geotechnical constraints
- Designed the in situ soil mix to provide a final mix strength similar to that of soil to maximize flexibility in the use of foundation piles for various redevelopment scenarios
- Integrated enhanced stormwater treatment features, including sand filters and pretreatment, within the environmental caps to maximize the development footprint