Hennepin County planning anaerobic digestion facility

Hennepin County Minnesota has set a goal of recycling 75 percent of its waste and sending zero waste to landfills by 2030.

Part of that plan is building an anaerobic digestion (AD) facility in Brooklyn Park near the county’s transfer station at 9401 83^rd Avenue.

The Hennepin County Anaerobic Digestion Facility and Eco-Center will be capable of processing 25,000 tons per year of organics, according to the county's website.

Hennepin County Waste Reduction and Recycling Supervisor Ben Knudson says the county hopes to award a contract for the design and construction of the AD facility later this year or in early 2023.

Although there are plans germinating in other counties to establish an AD facility serving residents and businesses, Knudson says the Brooklyn Park facility could be a first.

“I think there are maybe a few [AD facilities] in Minnesota that are more agriculture-based, but as far as diverting organics and food waste from residential streams, this would be unique in the area,” he says. “Ramsey and Washington counties—they’re actually moving forward with plans for anaerobic digestion facilities, too.”

The AD facility should lighten the load of two nearby composting facilities, as well as landfills which the state of Minnesota indicates require an additional 6 million tons of capacity over the next seven years, he says.

“The two compost sites are bumping up against their capacity, too,” Knudson says. “If we step back and look at the metro area, there’s a lot of pressure on existing options, and it would be nice to add some capacity to the system.”

To divert as much as possible from landfill, Knudson says the county has been working with area businesses and residents to separate recyclable and compostable material from waste in the residential and commercial markets.

“The county board adopted a climate action plan in 2021,” he says. “Hennepin County is in the process of developing a zero waste plan, and we see anaerobic digestion as something that can help us make progress toward our climate action goals and our zero waste goals.”

Facility details

Fueling the need for an AD facility are 77,000 residents and businesses that participate in an organics recycling program, according to an overview of the process and facility. Currently, organics comprise about 30 percent of the county’s waste.

The facility will produce biogas that can be used as an energy source in a variety of areas and digestate, a soil amendment.

In addition to diverting waste from landfills and the two area composting facilities that are nearing capacity, the AD facility will also cut transportation costs and greenhouse gas emissions because the composting facilities require 40- to 50-mile drives, the county says.

The Hennepin County Anaerobic Digestion Facility and Eco-Center also will provide educational experiences, house a green jobs learning center, include an on-site urban farm and greenhouses and deliver healthy food to the county's hunger relief partners.