NuStar’s Blue Island marine oil terminal is located on the north shore of the Calumet-Sag Channel, 20 mi south of Chicago. The existing wharf structure consists of two river barges sunk in-place in the mid-1950s. The steel barges are filled with gravel and concrete ballast and topped with a concrete slab to provide an even walking and driving surface. In the early 2000s, steel H-piles were driven along the waterside to prevent the barges from drifting into the channel. SGH performed an initial condition assessment of the existing steel and concrete wharf structures and designed repairs and upgrades.