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Sappi, farmers work together to save money (and the world)

Lime mud is loaded into a spreader for use on farmers’ fields to increase the soil pH to levels best suited for their crops. Special to the Pine Journal1 / 2
An aerial shot of the Cloquet Sappi mill shows the mill and the landfill on the far side. Thanks to efforts to reduce waste, the landfill, originally expected to be full by 2012, is now has a life expectancy of 25 years. Special to the Pine Journal2 / 2

Is the Cloquet Sappi mill the greenest in the world?

While there hasn't been an official trophy awarded by pulp and paper mills worldwide, Cloquet Sappi manager Mike Schultz is quite certain we have a winner here.

It always amazes local people when they find out the Cloquet mill is considered the most environmentally friendly mill in the world.

"Right here in little old Cloquet, Minnesota," he said with a satisfied smile.

Gone are the days when people used to talk about the "smell" of the paper mill that permeated the air in town — that ended when the new, more efficient pulp mill was constructed some 20 years ago, Schultz said, pointing out that the Cloquet pulp mill (which also now makes chemical cellulose) is still the newest pulp mill in North America.

What began years ago as an effort to prolong the life of the on-site landfill, the Cloquet mill has turned into one of the environmental success stories of the millennium. It's been a war fought on many fronts, most of them involving reusing waste that used to end up in the landfill or the sewer, along with a shifting focus to using renewable energy as much as possible.

It all began with a wake-up call.

In 2004, at the rate the mill was putting material into its on-site landfill, officials calculated they had eight years of life left. The landfill was going to be full by 2012.

"To get a new permit for a landfill in Minnesota is an act of God," Schultz said. "The expense of landfilling off-site would have been incredible."

They started making a concerted effort to reduce their waste, Schultz said, and went from 126,000 cubic yards of material down to 95,000 the following year.

"We just kept going," he said. "51 (tons), 45, 43 ..."

They got as low as around 18,000 tons of waste being landfilled in the early years of this decade before the transition to chemical cellulose brought that number back up to around 30,000 in 2014. Now they're back down to around 20,000.

"Now, after 2016, we have 25 years of life yet (in the landfill), instead of being closed six years ago," Schultz said.

The program that has literally made the biggest difference is the mill's "beneficial use" program, which began around 2005. Local Sappi officials work with Troy Salzer of the Carlton County Extension Agency and local farmers to take the mill's byproducts — lime mud and boiler ash — and put these materials on the farmers' fields to increase the soil pH to levels best suited for growing the kinds of crops they're trying to grow.

Environmental Manager Rob Schilling compared it to watching his grandmother take the ash from her fireplace and dump it in her garden when he was a little boy.

"I always thought that was the craziest thing," he said, "but we're doing the exact same thing. Our boilers are like big fireplaces. We're burning virtually all wood and the ashes at the bottom of our boiler are like the ashes at the bottom of my grandma's fireplace. And it's a really important nutrient for agriculture."

Salzer acts as the go-between for the mill and the farmers and the state agencies that permit the programs. The lime mud is distributed through the Minnesota Department of Agriculture's ag-lime program. The boiler ash program is overseen by the Minnesota Pollution Control Agency.

"I help the farmers to better understand exactly what the product is, how it is produced and how it will benefit them," Salzer said. "Once they decide (to enroll), I test the soil and use GIS to identify the location. I determine the application rate based on the soil test."

Salzer estimated about 100 farmers a year participate in the program, which helps make "the nutrients in the soil more available to the plants." Most farmers generally mix the two products, because the lime gets into the soil faster, while the ash has a more sustained release over time, Salzer said, adding that the farmers are mostly growing alfalfa, grass and hay.

"It's been a fantastic program to be part of. I've seen yields go from three-fourths a ton per acre up to five or six tons per acre," Salzer said. "In terms of bales, that is like going from two bales to 11 or 12 bales per acre.

"We deliver the material, we spread the material and the farmers see the benefits," Schilling said, "almost overnight."

It's certainly been helpful to Wrenshall-area dairy farmer Peter Laveau, who first started working with Minnesota Power and Light when MP&L began a similar program in 1991, then with Sappi when the mill began to make similar products available. Schilling said both products serve a very similar purpose in raising the pH of soil. The boiler ash has the added benefit of having micronutrients that are also important for crop growth and yield. It's almost like a multivitamin for dirt, he said.

"The lime and potassium really helps with developing a good stand of alfalfa," said Laveau, noting that he had purchased commercial fertilizers before. "But with the milk prices, sometimes I didn't have money to buy it and then I didn't have a good stand of alfalfa."

Sappi doesn't charge the farmers for the wood ash or lime, and only recently started charging them a portion of the costs of transporting the byproducts to their farms and spreading it on the fields.

Salzer said that's OK.

"It's always been a win-win," he said. "And I think the transition to partial payment last fall has helped the farmers value it even more. Otherwise they'd be paying for commercial fertilizer ... or going without. And Sappi would be landfilling. That would be such a waste. The soil needs it."

"I'm glad Sappi is doing it," Laveau said. "I hope they keep doing it. It's beneficial for us and for them I think."

Although the program started small, it has grown every year.

"Last year, I believe we distributed 85,000 tons of ash and lime through those programs," Schilling said. "That's 85,000 tons that would go into the landfill, but instead it went out to the local community and our local farmers to support them."

The mill has also implemented other changes to become more environmentally friendly and save money and landfill space. They quit burning gas and oil (and a little coal) and switched to renewables (the bark and connective "glue" of trees that isn't used for making paper). They stopped landfilling the paper sludge produced in the waste treatment plant and now they burn it to make renewable energy.

Schilling explains that the sludge produced by the mill is mostly fiber.

"We dewater it, dry it, put it in the boilers and produce steam," he said. "We burn 35,000 tons of that sludge material per year rather than landfilling it."

A graph in the Sappi North America Sustainability Report (which Schilling worked on) shows how the Cloquet Sappi mill measures up to the United States in terms of its energy profile, and to U.S. pulp and paper mills. The average amount of renewable energy in the U.S. is 10 percent, versus 54.5 percent for pulp and paper mills, versus 80.4 percent for the Sappi mill.

"We have the highest percentage of renewable energy of any mill we know of," Schultz said. "Over 80 percent of the manufacturing produced is all from renewable sources ... on site here in Cloquet."

Schultz said the goal is to make the landfill last even longer than the currently predicted 25 years, to keep increasing that life span by decreasing waste.

Schilling takes it one step further.

"We used to joke that we wanted to get the landfill past Mike's retirement date, then we joked that we wanted to get past my retirement date. Now my goal is really to get this to be a zero-waste facility and make the landfill last forever," Schilling said. "I don't know if we can be there tomorrow, but I think we can get there."