In Duluth, Minnesota, millions of gallons of warm, treated wastewater are discharged into the Saint Louis River each day.

Slick: “Right now, the effluent temperature coming out of the end of the process is about 90 degrees … so there’s a huge amount of waste heat there.”

Jodi Slick is with Ecolibrium3, a nonprofit based in Lincoln Park, the largely low-income neighborhood where the wastewater plant is located.

Her group, along with the city and other partners, is working on a plan to harness that waste heat and use it as a source of energy. They’ve received a $700,000 federal grant to design the project.

The system would use pumps to distribute heat from the wastewater through a network of underground pipes — providing the main heat source for hundreds of homes in the neighborhood.

A few similar systems are already in use in Finland, Denmark, and China.

Slick says she’s excited about using the approach in the U.S., where wastewater treatment plants are often located in low-income communities that are exposed to a disproportionate number of environmental hazards.

Slick: “We have the possibility of opening up a brand new energy source that turns what has often been considered an environmental justice burden into a benefit for these neighborhoods.”

Reporting credit: Sarah Kennedy / ChavoBart Digital Media