How the project was accomplished
The southern-most Fox River Cleanup Operating Unit One (OU1) is the Little Lake Butte des Morts area where this website's information captures work completed in May 2009.
The scope of this project was significant in size. Removal of PCB-contaminated lake sediment began in 2004, and the in-water portion of the project was completed in May 2009. Over the course of the six-year project, more than 370,000 cubic yards of PCB- impacted sediment was removed and approximately 260 acres of lake bottom with low-concentrations of PCBs were remediated with sand cover or armored caps. Restoration of the staging areas was completed following completion of in-water remediation.
How this project was accomplished is described in the sections below and using the links.
Dredging Activities: Sediment Dredging
PCB-contaminated sediment was removed from the lake bottom using hydraulic dredging methods.
Staging Areas: Staging Areas
Staging areas on either side of the lake were established to 1) house equipment for the operations of sediment dewatering, water treatment, and landfill transportation preparation, and 2) clean sand/gravel storage.
Landfill Disposal of Sediment: Landfill Disposal
Once the sediment was dewatered, trucks hauled the sediment for disposal at the Hickory Meadows Landfill.
Sand Cover & Armored Caps: Sand Cover & Armored Caps
As part of an optimized remedy, sand covers and armored caps were installed to isolate the low PCB-concentrated sediment in place.
Dredging Activities: Sediment Dredging
PCB-contaminated sediment was removed from the lake bottom using hydraulic dredging methods.
Staging Areas: Staging Areas
Staging areas on either side of the lake were established to 1) house equipment for the operations of sediment dewatering, water treatment, and landfill transportation preparation, and 2) clean sand/gravel storage.
Landfill Disposal of Sediment: Landfill Disposal
Once the sediment was dewatered, trucks hauled the sediment for disposal at the Hickory Meadows Landfill.
Sand Cover & Armored Caps: Sand Cover & Armored Caps
As part of an optimized remedy, sand covers and armored caps were installed to isolate the low PCB-concentrated sediment in place.