Sources: CDM Smith Inc., Boston; U.S. Environmental Protection Agency; CP staff
On the heels of an accelerated February-May excavation schedule averaging 1,500 tons of contaminated soil per day, the CDM Smith – Mott MacDonald Joint Venture has shifted to the 18-month concrete phase of an 8-million-gallon combined sewer overflow (CSO) storage tank in the Gowanus neighborhood of Brooklyn, N.Y. The 156- x 425- x 50-ft. structure anchors a pollution control plan for the 1.8-mile Gowanus Canal, whose decades of exposure to industrial operations led to an Environmental Protection Agency Superfund site listing in 2010.
Cast-in-place wall, column and roof work will proceed in parallel with construction of ancillary influent and outfall structures, which will connect the tank to the existing New York City Department of Environmental Protection’s Gowanus Pump Station. The conveyance infrastructure and tank will intercept and—pending available wastewater treatment plant capacity—store combined storm and sanitary sewage that would otherwise overflow into the Gowanus Canal.
