Today DC Water unveiled its $470M waste-to-energy project that is producing a net 10 megawatts (MW) of electricity from the wastewater treatment process, providing clean, renewable energy to power about one-third of the Blue Plains plants energy needs. DC Water CEO and General Manager George S. Hawkins was joined by District of Columbia Mayor Muriel Bowser, Congresswoman Eleanor Holmes Norton, EPA Acting Deputy Administrator Stan Meiburg, US Department of Energy Deputy Assistant Secretary Kathleen Hogan and local elected and appointed officials to commission the project.
The facilities include a dewatering building, 32 sleek thermal hydrolysis vessels, four concrete 80-foot high anaerobic digesters that hold 3.8 million gallons of solids each and three turbines the size of jet engines.
The project, which broke ground in 2011, was only viable through the use of innovative technology never before used in North America. DC Water brought the CAMBI® thermal hydrolysis process to the continent; in addition, Blue Plains is now the largest thermal hydrolysis installation in the world. Thermal hydrolysis uses high heat and pressure to "pressure cook" the solids left over at the end of the wastewater treatment process. This weakens the solids cell walls and the structure between cells to make the energy easily accessible to the organisms in the next stage of the process--anaerobic digestion. The methane these organisms produce is captured and fed to three large turbines to produce electricity. Steam is also captured and directed back into the process.
Finally, the solids at the end of the process are a cleaner Class A biosolids product that DC Water uses as a compost-like material. Biosolids products are currently being used around the District for urban gardens and green infrastructure projects. DC Water is also working to bring a compost-like product to market.
"This is yet another example of the District leading the nation in the adoption and implementation of sustainable practices," said District of Columbia Mayor Muriel Bowser. "DC Waters Blue Plains facility is converting waste to clean water and a nutrient-rich soil byproduct, producing energy and helping to put the District on the path towards a zero waste future."
DC Water CEO and General Manager George S. Hawkins, said "This project embodies a shift from treating used water as waste to leveraging it as a resource. We are proud to be the first to bring this innovation to North America for the benefit of our ratepayers, the industry and the environment."
Added Matthew Brown, DC Water Board Chair, "The Board of Directors approved this voluntary investment to create a better class of biosolids and generate 10 MW of power to cut the electricity bill at the Blue Plains plant, which is the single largest consumer of electricity in the District. Additionally, the cleaner biosolids can be applied locally, saving millions of dollars in hauling costs."
DC Water conducted more than a decade of research before bringing these facilities online. DC Waters world-renowned wastewater research program includes dozens of researchers conducting their Ph.D. and masters theses on DC Water projects.
The project received the 2012 Grand Prize in Planning Award from the American Academy of Environmental Engineers & Scientists, the 2012 Global Honour Award in Planning from the International Water Association, as well as one of two WERF Excellence in Innovation Awards, first presented at WEFTEC 2011.
The ceremony included the unveiling of a plaque to dedicate the facilities to Walter F. Bailey, who retired last month after serving the organization for 43 years. Mr. Bailey was the Assistant General Manager for Wastewater Treatment and an industry leader in performance and innovation, with several patents and dozens of awards to his credit.
The distinguished guests joined Mr. Hawkins to plant a potted tree with the Class A biosolids.
For more information, visit www.dcwater.com/digesterdedication
SOURCE: DC Water