A semi truck filled with pallets of energy drinks pulls up outside the Fremont Regional Digester, about a half hour from Muskegon.
The cargo joins several semiloads that have already been delivered and await digestion. Stacks of drinks line the delivery bay and twist around the corner of the facility.
“It would all just be stuck in a landfill and not used,” said Leon Scott, the facility manager at Fremont Regional Digester.
That might soon be the case. This is one of the last deliveries the Fremont digester will receive. It’s shutting down after a years-long argument with state regulators.
The ultimate outcome of that disagreement could have implications for clean water and clean energy in Michigan.
How it works
Digesters are a growing industry in Michigan. They take organic matter — like food waste or manure — and break it down in an oxygen-free environment. The gases that process emits are burned to generate electricity.
The Fremont facility does that mostly with manufacturing food waste – milk jugs, energy drinks, baby food, jellies and juices that are too close to expiration date to sell.
Those products, which often come in containers, are shredded. Then the contents are shuttled into a waiting tank before heading to three giant tanks full of specialized bacteria, which break down the food and excrete biogas — a combination of methane, carbon dioxide and a few other gases.
In Fremont, that gas is burned onsite to generate electricity and then sold to the grid. That process is a point of pride for Scott.
“That engine — you hear that? That’s the generator running,” he said. “That’s putting power into the grid right now. So, that’s a good sound. That’s a green sound.”
Falling silent
Fremont Regional Digester operators say it processes over 100,000 tons of food waste each year, diverting it from landfills and powering about 3,500 local homes.
Now, the facility is shutting down. The issue isn’t with the food waste or the energy, it’s with digestate — the liquid, nutrient-rich byproduct left over from converting food into biogas.
Generate Upcycle, the San Francisco-based company that owns the digester, can’t agree with Michigan’s Department of Environment, Great Lakes, and Energy on which permit it should operate under.
Since Generate Upcycle acquired the digester in 2017, it has operated under an agricultural use authorization though the state’s solid waste program. That’s allowed the company to spread the nutrient-rich digestate on nearby farm fields.
But in 2021, EGLE notified the company that its permit had to be renewed as a groundwater discharge permit within its Water Resources Division. The consistency of the digestate was fluid enough to be considered liquid waste, EGLE said, so spreading it needed to be more carefully regulated.
That decision has been an ongoing problem for Generate Upcycle.
“Fundamentally, our material, our process, our product, is not something that the water resources group has permitted before,” said Dan Meccariello, the vice president of operations at the company. “We are very much a square peg in a sea of round holes.”
Digestate contains nutrients, minerals and metals that can be good for the land and for crop growth, but if it’s applied wrong or if there’s too much of it, it can harm water quality and cause many of the same problems as fertilizer runoff.
For more than two years now, Generate Upcycle has received extensions on its current permit from EGLE.
But late last year, the company announced its decision to idle the Fremont digester. Company officials say that with the financial burdens created by the new permit requirements, it no longer makes sense to continue operating the facility.
In a statement, EGLE said it’s “supportive of anaerobic digestion and the energy it produces,” as well as the fact that it reduces food waste. But officials said the department “is also statutorily mandated to ensure that environmental and public health is protected when facilities land apply digestate on farm fields.”
EGLE says it wants to mitigate the risks that misapplying liquid digestate poses to surface and groundwater. Those risks include the development of harmful algal blooms, excess aquatic plant growth and the potential for other materials in the digestate to contaminate farm fields and food production.
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Categories: Michigan, Energy