The Top 10 Biggest Wastewater Treatment Plants
10. Blue Plains Advanced Wastewater Treatment Plant — Washington, D.C., USA. Capacity: 370 million gallons per day. Owner: DC Water. The plant began operating in 1938 as a primary treatment facility. In 1959 it was upgraded to accommodate secondary treatment, and it’s capacity expanded to 240 mgd to handle wastewater from four adjoining suburban counties in Maryland and Virginia. An ambitious improvement program is currently under way. One component is a project to reduce nitrogen from about 5 mg/l to under 4 mg/l by 2015, to meet new federal standards. Eight new reactor tanks with a capacity of 40 mil gal will be added, along with a 890 mgd pump station, post-aeration facilities, new channels and conveyance structures. The program manager for this $950 million project is AECOM, and the design engineer is CH2M Hill. PC Construction Co. is doing the site preparation and some of the tankage, while Ulliman Schutte Construction will be performing the mechanical and electrical work. Because of the 153-acre site’s proximity to the Potomac River, a 50-ft deep slurry wall “bathtub” will be built around the new denitrification tanks to avoid groundwater intrusion. Another major initiative, called the Clean Rivers Project, will reduce combined sewer overflows by digging a 4 mile-long, 23-ft dia tunnel and building a large pumping station. Traylor Skanska Jaydee Joint Venture is currently excavating a 120-ft-deep, 132-ft dia shaft, prior to beginning the tunneling in 2013. The most innovative upgrade is the Cambi thermal hydrolysis process, which will “cook” sludge material under high pressure and steam to generate a better class of biosolids as well as generating 13 MW of power. Blue Plains will be the first plant in North America to use the process, which is already installed at 15 plants across Europe. Camp, Dresser & McKee (CDM) is the project manager and design engineer on the biosolids project, and the CDM Constructors Inc./PC Construction Co. joint venture will build the main process train and supporting infrastructure. The combined cost of the three projects is $4 billion.
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