Gresham, Oregon, wastewater plant achieves energy net zero status

By City of Gresham, Oregon | April 22, 2015

On Earth Day, the City of Gresham celebrated the ingenuity and collaborative spirit that made possible an environmental achievement – engineering the Pacific Northwest’s first energy net zero wastewater treatment plant. Achieving net zero status means that the plant makes about the same amount of electricity as it consumes in a year, saving tax dollars and protecting the environment.

Gresham’s plant is one of only a handful in the United States to achieve net zero status.

Gresham elected officials, city employees, community leaders, project supporters including Energy Trust of Oregon, and fourth-graders from Wilkes Elementary School studying energy in the Reynolds School District attended the Earth Day celebration at the plant, which is located at 20015 N.E. Sandy Blvd. on Gresham’s northwest side. The plant serves 114,000 customers in Gresham, Fairview and Wood Village and treats approximately 13 million gallons of wastewater each day before releasing it into the nearby Columbia River.

Organic matter from wastewater now fuels 92 percent of the Gresham plant’s power – right on site – using a process that turns this sludge into biogas. The City has nearly doubled its biogas production since 2012, when haulers started trucking in wastewater filled with fats, oils and grease from Portland-area restaurants and food service establishments. All this biogas is fed into two powerful engines that convert it to heat and electricity, which is used at the plant, with excess electricity sent out to the Portland General Electric grid. At the end of each year, any electricity not used by the plant is used to help families that receive energy assistance from PGE.

The remaining 8 percent of the power the plant produces comes from a 1,902-panel ground-mounted solar array.

By adopting these clean energy technologies, and making the plant more energy-efficient, Gresham is estimated to save $500,000 a year in electrical costs. The plant also makes money, bringing in around $250,000 a year in fees for accepting fats, oils and grease from regional food establishments.

We’ve turned our biggest energy user into our biggest energy producer,” Mayor Bemis said. “We protect our environment and our taxpayers. Now that’s green.”

Bemis, chair of the U.S. Conference of Mayor’s Energy Committee, continued, “Major achievements require bold leadership, and I thank former and current City Council members for their courage and vision. I thank the City staff, who embrace a spirit of innovation, despite a limited budget. And I thank our project partners. At a time when all of our resources are stretched, we must work together to take on grand challenges and succeed.”

The net zero achievement is the result of a decade of leadership, planning and persistence. Faced with rising utility bills and limited City funds, Alan Johnston, a senior engineer with Gresham’s Department of Environmental Services, began crafting a long-term plan and formed an energy management team to get the plant to cut energy usage and produce its own power.

Johnston partnered with the non-profit Energy Trust of Oregon, the Oregon Department of Energy, and Veolia, the international water, waste and energy management company, to fund and implement energy-saving solutions.

In 2005, Gresham purchased its first modern co-generator, the industrial engine that burns biogas to produce electricity and heat. In 2010, the City added the solar array. In 2012, it started trucking in fats, oils and grease, which nearly doubled biogas production. In 2014, it tripled storage capacity for fats, oils and grease. In January 2015, it added its second co-generator – which pushed the plant into net zero status.

Over the past decade, Gresham cut power usage by 17 percent by making the plant more energy efficient by purchasing energy-saving equipment and improving operations.

In all, Energy Trust provided more than $1.3 million in cash incentives to the city for energy production and energy-efficiency investments at the plant, as well as technical assistance and project development support. Energy Trust won the 2014 State Leadership in Clean Energy Award from the Clean Energy States Alliance for its long-term work with Gresham.

“The Gresham wastewater treatment plant’s comprehensive approach to cutting energy costs and using waste products and solar power to generate renewable electricity is a shining example for plants in Oregon and across the nation,” said Debbie Kitchin, board of directors president, Energy Trust. “We are pleased to have worked with the city’s dedicated energy management team, and look to apply lessons learned from this experience to help other wastewater treatment plants in Oregon achieve their energy goals.”

The Oregon Department of Energy provided almost $2.2 million in transferable tax credits.

“As remarkable as the Gresham facility is, the most exciting part is that we have the potential to replicate net zero projects like this across the state,” Michael Kaplan, Oregon Department of Energy director said. “ODOE is committed to helping partners in Oregon communities learn from, and build on, the success we see here at Gresham with tools and resources to move innovative projects forward.”

Veolia operates and maintains the plant with the City in an award-winning public-private partnership, and brings critical technical expertise to the operation. William J. DiCroce, president and COO of Veolia North America’s Municipal & Commercial Business, said Gresham is a model of sustainability for cities around the world.

“Veolia can help replicate Gresham’s success for any city that wants to help build a better future while cutting costs,” DiCroce said. “Many of our environmental problems are solvable if we set a big vision and go after it – together.”

At the celebration, Mayor Bemis announced a community partnership that will keep spirit of collaboration and innovation behind the net zero achievement alive long past Earth Day.

In partnership with the Reynolds School District, Pamplin Media Group and MetroEast Community Media, the City will produce classroom materials that elementary school students can use to understand the energy-producing processes at work at the plant – a favorite field trip destination. Reynolds teachers will provide educational guidance, Pamplin will print a booklet, and MetroEast will produce a video. All these services are provided for free, and materials will be available to all student groups visiting the plant.