Construction of the Confined Disposal Facility (CDF) Photos
Approximately 20-ft tall clay dikes hold the dredged material, and a 14-ft high center dike aids sediment and water management. The center dike separates the two CDF cells. This photo shows the construction of the center dike using a timber core fill. [Source: USACE]Placing clay for the dikes around the CDF. [Source: USACE]A low permeability soil-bentonite slurry wall was installed around the perimeter of the site to prevent the outward migration of groundwater. This slurry wall was constructed on the north, east, and west perimeter of the site. This photo shows the excavation of the slurry wall. [Source: USACE]Tar encountered at the ECI site during excavation of the slurry wall. [Source: USACE]Digging the trench for the slurry wall installation. [Source: USACE]Underground structures were left when the site was razed by previous owners. These obstructions were removed as needed to build the CDF. This photo shows the excavation of an obstruction while digging the trench for the cutoff wall. [Source: USACE]A sealed sheet pile cutoff wall at the canal on the south side of the CDF hydraulically isolates the groundwater at the site from the Lake George Branch of the Indiana Harbor and Canal. This photo shows the construction of the sealed sheet pile cutoff wall. [Source: USACE]The sealed sheet pile cutoff wall utilizes a low hydraulic-conductivity sealant to prevent the outward migration of groundwater. [Source: USACE]The gradient control system pumps groundwater from the CDF to an onsite water treatment plant. The system consists of 96 vertical extraction wells that help to prevent offsite migration of contaminated groundwater from the CDF. This photo shows the installation of one of the groundwater extraction wells. [Source: USACE]
