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Scope of Work:
Excavation and off-site disposal of PCB contaminated soil located at a former automotive junkyard
¨ General site preparation included clearing and grubbing, removal of junkyard debris, installation of a full perimeter security fence, and installation of the temporary scale, scalehouse, and related project offices.
¨ Excavation of over 41,000 CY of PCB contaminated soil was performed in 50’ x 50’ plan grids with typical excavation depths of 2-4’ below grade. Approximately 80% of the site had PCBs below 50 ppm with the balance of the site having TSCA regulated levels.
¨ Contaminated soil was excavated in accordance with the grid plan and then loaded out for off-site disposal. Two non-hazardous landfills were utilized for the 59,300 tons of non-TSCA regulated impacted soil. Over 16,000 tons of TSCA regulated soil was also shipped to a TSCA permitted landfill.
¨ In addition to the soil and debris, several stockpiles of PCB impacted tires were accumulated throughout the project. Due to the presence of PCB soil residue throughout the stockpiles, the tires were sheared in half and shipped as non-TSCA, PCB impacted debris under a special profile.
¨ Specialty excavations were performed in several areas. Two residential properties and three commercial properties were located within the project limits and several excavations were performed in their yards and lots. Special measures included hand digging around sensitive plantings or structures, and the removal and replacement of fences, driveways, pools, septic tanks, and other features. Temporary access to homes and businesses had to be maintained throughout the project, requiring excavation and restoration to be performed in subdivided sections throughout the properties.
¨ Wetland excavation and restoration was also required in a ~1 acre parcel in order to remove 600 CY of impacted sediment. DAC accessed this area using a wood chip haul road and low ground pressure equipment. Restoration of the wetlands included placement of high organic wetland soil and approximately 300 tree and shrub plantings. Work in this area was complicated by the presence of ‘floating islands’ of vegetation and the presence of junkyard debris in the fill areas.
¨ Construction water was managed on-site with a 100-gpm trailer mounted water treatment system. Treatment train components included 40,000 gallons of storage capacity, particulate filters, organoclay and activated carbon treatment vessels. All water was treated in accordance with state requirements for discharged to an on-site pond.
¨ Health and safety was a top priority on the project with high scrutiny in the community protection component. Neighboring properties were extremely sensitive to the risks posed by dust or chemical migration during remedial construction. A perimeter air monitoring system was employed with additional documentation samples performed as neighbor’s request to document that PCB dust migration was not a problem on the project.
¨ Final restoration of the site included removal of all temporary facilities, topsoil and seeding over 17 acres. Additional trees and shrubs were planted in various areas throughout the residential and commercial properties.
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