WALNUT CREEK, CA, Nov. 12, 2015 -- The American Public Works Association's (APWA) Oregon Chapter recently announced that it has selected the City of Gresham as winner of the Public Works Project of the Year Award in the Environmental category (including Water, Wastewater and Stormwater).
The Gresham Wastewater Treatment Plant (WWTP) was recognized for its Cogeneration (Cogen) Expansion Project, which allowed the plant to attain the status of net-zero energy (NZE) (see: "OR wastewater treatment plant first in Northwest to achieve net-zero-energy status").
With the completion of the Cogen Expansion Project, the Gresham WWTP has achieved its seven-year-old goal of achieving NZE. Using the biogas byproduct from anaerobic digesters to fuel cogeneration engines, the plant now generates more electricity than it uses on an annual basis and has turned the city's biggest energy user into its leading energy producer.
Carollo Engineers served as the primary consultant on the project. Jeff McCormick, associate vice president and principal engineer of Carollo, said, "We believe that the Gresham WWTP is a shining example of a new way to look at wastewater treatment, and it's blazing a trail to be emulated nation-wide. It's not just about treating waste, it's about recovering resources -- in this case, generating renewable energy worth over $500,000 annually."
As the Pacific Northwest's first NZE WWTP and one of only a few in the United States, the Gresham WTTP is gaining national and international attention -- helping to promote the use of this reproducible technology. It is estimated that only 8 percent of WWTPs in the U.S. with anaerobic digestion generate electricity or hot water as a renewable energy resource.
With the completion of the Cogen Expansion Project, all months since February 2015 have been NZE months. With the expansion, a second 400-kW CAT cogen unit was installed, which enabled the WWTP to generate all the energy needed to operate the plant. The WWTP's first NZE day was February 12, 2015, and trends indicate that 2015, and all future years, will be NZE for the plant.
The expansion also provides a boost to the community. By adopting this technology and becoming more energy efficient, Gresham is saving approximately $500,00 per year on electricity. The project will also help the city to meet two key goals of its sustainability policy implemented in 2009: to have an 80-percent reduction in city greenhouse gas emission by 2050 and to use 100-percent renewable energy for city facilities by 2030.
See also:
"WERF Sponsors Research on Net-Zero Energy Solutions"
"Carollo earns AWPA Public Works Project of the Year Award for water storage efforts"
About Carollo Engineers
For more than 80 years, Carollo Engineers has provided a full range of innovative planning, design and construction management services to meet the water and wastewater needs of municipalities, public agencies, private developers and industrial firms. To learn more, visit www.carollo.com.
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