Minnesota bill proposes study of wastewater heat recovery potential

A new bill in the Minnesota House aims to explore how wastewater could serve as a renewable heating source for buildings, positioning the state to expand use of a technology already deployed in parts of Europe and North America.

Sponsored by Rep. Larry Kraft, HF2317 would allocate $3 million from the state’s Renewable Development Account to the Minnesota Pollution Control Agency to study wastewater treatment facilities where heat recovery could be implemented. The proposal also includes funding for engineering review and design of two pilot projects—one in the Twin Cities metropolitan area and another in Greater Minnesota.

The concept centers on capturing thermal energy from treated wastewater before it is discharged, using it to supply district heating systems for residential and commercial buildings.

“Many wastewater facilities already recover some of their wastewater heat for use internally in their own processes,” Kraft said in a press release. “What this bill targets is different: the thermal energy in the treated wastewater itself, which is currently being discharged into our rivers and waterways. This is energy communities have already paid to generate and, right now, we’re not using it.”

Kraft added that prior studies in St. Paul and Duluth identified significant untapped potential. “Recent studies conducted in St. Paul and Duluth in conjunction with federal grant opportunities identified enough recoverable thermal energy at wastewater treatment facilities to serve as the primary energy source for the district heating networks serving approximately 40 million square feet of building space,” he said.

The bill was recently laid over for possible inclusion in a larger omnibus energy package.

Supporters say the initiative aligns with the Renewable Development Account’s mission to fund non-fossil-fuel energy projects. The account is financed through fees paid by Xcel Energy for storing nuclear waste at its Prairie Island and Monticello facilities.

Utilities and district energy providers are already exploring similar concepts. In St. Paul, Ever-Green Energy is working with local partners on an initiative to integrate wastewater heat into its district energy system.

“The technology is proven, deployed at scale in Europe since the 1980s, with several smaller projects in operation across North America,” said Luke Gaalswyk, president and CEO of Ever-Green Energy, in a press release.

If advanced, the study and pilot projects could help determine the feasibility of scaling wastewater heat recovery across Minnesota, offering a potential pathway to reduce emissions while maximizing the value of existing water infrastructure.