The Gresham (Oregon) Wastewater Treatment Plant produces enough sustainable energy to cut what used to be a $500,000 annual electricity bill to zero.

That and other accomplishments deserve recognition from the community. “That was our biggest challenge,” says Elizabeth Coffey, the city’s communications manager. “We put in all this work and got a terrific result, but we weren’t done. It was up to us to explain to our community why this was so important, and why and how wastewater treatment plays a key role in everyone’s lives.”

In line with that, the city held an Earth Day event last April and has continued to keep the plant’s accomplishments front and center.

Creating energy

The Gresham plant turns biogas from digestion of biosolids and fats, oils and grease (FOG) into electricity and heat. Add a solar energy array and it’s enough to power the entire plant, which serves 114,000 residents and is operated and maintained in cooperation with Veolia in a public-private partnership. Gresham is among a handful of plants in the United States that have reached net zero status.

In early 2015, project leaders decided that Earth Day made the most sense for a public announcement. The April 22 celebration included elected officials, employees, community leaders, project supporters including the Energy Trust of Oregon, and 80 fourth-grade students from Wilkes Elementary School.

“The kids are the ones who will carry sustainable practices forward,” says Coffey. “That’s why it was so important that this celebration be shared with students. Our focus on Earth Day and our outreach since then has urged kids to be ‘net zero heroes.’”

As part of the celebration, Mayor Shane Bemis declared, “We’ve turned our biggest energy user into our biggest energy producer. We protect our environment and our taxpayers. Now that’s green.”

After his proclamation, Bemis counted down as the Wilkes students formed a giant zero on the lawn of the plant. The event created a great photo opportunity for the news media and allowed plant personnel a chance to spotlight their achievements. “We got a lot of media coverage around the event, which was a great way for us to spread our message,” says Coffey. 

Further outreach

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

With the Reynolds School District, Pamplin Media Group and MetroEast Community Media, the city has produced classroom materials that elementary school students can use to understand the energy-producing processes at work at the plant, which is a favorite field trip destination for all ages.

Reynolds teachers provided educational guidance, Pamplin printed an interactive booklet, and MetroEast produced a video posted on the city’s website and available on YouTube. Besides outlining the energy process, the booklet celebrates the vision and drive of the project’s mastermind, engineer Alan Johnston.

“Our outreach materials are presented in a way that is very understandable to young students,” says Coffey. “They all focus on the process of turning wastewater and FOG into renewable energy. It’s information that is specific to our process, but the idea can be carried to any community looking into becoming more sustainable.”

Coffey points out that the program wouldn’t be possible without the city’s community partners coming to the table. She suggests identifying viable partners as the first step toward any successful wastewater treatment outreach program.

“You have to find partners who are passionate about the environment and getting the word out to kids, and who offer resources that you may not have at your disposal,” she says. “Kids have that wonder and excitement. It’s so important to tap into that.”

Sustainable history

The city installed its first biogas-fueled generator in 2005 and added a solar array five years later. In January 2015, the city installed a second generator that created enough power to bring the plant to net zero status. The 10-year development cost $9.1 million, of which the city paid $5.6 million. The rest came from government sustainability and infrastructure grants and tax incentives.

Organic matter from wastewater now produces 92 percent of the plant’s power. Heat from the engines is used for plant processes, and surplus electricity is sent to the Portland General Electric grid. The remaining 8 percent of the plant’s power production comes from a 1,902-panel ground-mounted solar array.

In 2012, the city started feeding FOG from restaurants into the digesters. Now the city charges restaurants for taking the material. “We collect about $250,000 annually in FOG fees,” says Coffey. “It helps us put a positive value on sustainability.”