GREEN BAY - Will Kress wanted Wisconsin's first new mill in 30 years to be more than just a modern paper plant.

He wanted Green Bay Packaging to "operate the most environmentally friendly mill system in the United States."

That quest was validated this week when, one year after the mill opened, UL certified it as a net-zero water user that returns as much or more water of the same quality to the Great Lakes as it draws. The mill accomplishes this via a one-of-a-kind partnership with NEW Water, the Green Bay area wastewater utility, that allows it to recycle waste water and supplement it with partially treated wastewater from the utility.

"It took an awful lot of cooperation and creative thinking by Green Bay Packaging, NEW Water, the (Wisconsin) DNR, the city of Green Bay and Brown County," NEW Water Executive Director Thomas Sigmund said. "They took some very unique situations and created wins for everybody, including the environment."    

Green Bay Packaging executives hailed the independent validation of its claims as a new standard for sustainable operations in the paper industry — traditionally a heavy user of energy, wood and water. They note the $500 million mill project retained and created jobs, produces more paper and reduces the company's environmental footprint.

Lisa Bauer-Lotto, Green Bay Packaging's corporate director for environment and sustainability, said investments in the new mill specifically sought to reduce greenhouse gas emissions, use more recycled material in production, and be a net-zero water user. 

"This is good for the paper industry," Bauer-Lotto said. "We're making more paper while using less energy, emitting less greenhouse gas, using less water and all while meeting consumer and customer growth."

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UL, which stands for Underwriters’ Laboratories, examined the company's claim, verified it, and on Jan. 27 published the first industrial global standard for evaluating net-zero water use. UL's evaluation included months of water meter data and factored in things like evaporation and the moisture in the containerboard the mill produces, Lotto said. 

Green Bay Packaging expects the designation will meet growing demand for sustainably-sourced packaging in the food service, home goods, and appliance industries.

Bauer-Lotto said the company's customers regularly ask about sustainability measures and increasingly request independent verification. Since this is "on the cusp of what's possible," she said, the company wanted to document it. 

"Third party validation is the direction you see for many things. It's becoming an expectation at some junctures," Bauer-Lotto said.  

The company recycles and re-uses water to achieve its net-zero status, but the paper-making process does require some fresh water. It's important to note the company hasn't turned off the spigot.

In fact, the Green Bay Water Utility's 2020 annual report indicates Green Bay Packaging used 277 million gallons of water in 2020, making it the utility's seventh largest customer. Bauer-Lotto said the company will continue to look for ways to reduce the volume of water it buys from the water utility. 

"Water is the lifeblood of paper-making," said Bob Mihalski, Green Bay Packaging's director of mill sales, trades, and continuous improvement, during a tour of the mill. 

The paper machine stretches the length of 2.5 football fields and the mill can store as much as 3 million gallons of water, which the company repeatedly reuses to make containerboard. 

Green Bay Packaging has installed systems in the new mill to reclaim and reuse as much water as possible from each stage of the paper-making process. Eventually, though, the reclaimed water becomes too laden with organic materials to be used to make paper.  

That’s where the water-treatment partnership with NEW Water comes in.

Water from the mill has more solid and organic material in it than the municipal wastewater treatment plant can handle, so Green Bay Packaging built a pre-treatment facility on site that removes as much as 90% of the solids before piping the water over to NEW Water for additional treatment.

NEW Water then mixes the mill's water with wastewater it receives from across the Green Bay region and treats it again to further reduce organic matter and solids.

IT then pumps a larger volume of treated water to Green Bay Packaging than it receives from the mill. Green Bay Packaging further treats the water on-site before putting it back to work in the paper production process. 

The company, in order to meet the net-zero criteria, needs the additional water to offset the moisture that remains in the paper as well as steam escaping from the mill. 

Matthew A. Szymanski, vice president of mill operations, said company leaders initially thought, while planning the new mill, that the reclaimed water system was a "blue-sky," pipe dream sort of idea. The partnership with the public utility was an essential piece of reaching net-zero water use that turned it into a "we can make this thing happen" idea, he said.

"The partnership we’ve been able to form with the county and city and NEW Water is really critical on this coming together. There was a lot of effort. It was a pretty special thing that happened," Szymanski said.

Sigmund said the arrangement benefits NEW Water and the region because the system puts the utility's wastewater to work rather than requiring the extensive level of treatment that’s needed before it can be discharged into the bay. 

Some of Green Bay Packaging's wastewater is mixed with NEW Water's wastewater and treated to meet quality standards for discharge into the bay. But the system sends a large volume of reclaimed wastewater, currently about 1.3 million gallons per day, to Green Bay Packaging. 

That also reduces the amount of water that the mill needs from the Green Bay Water Utility.

The result is a net benefit to the environment, Sigmund said. 

"This one took a village. Every party in it needed to keep their eye on the desired end result as we worked through the details. And there were a ton of details," Sigmund said. "They didn’t get hung up on any one little thing that could have derailed it. It’s a testament to all the parties involved."

Inside the mill, the company takes recycled paper products on a journey from 99% water to the components of containerboard.

The process starts by using a hydropulper to combine boxes, packaging materials and office-type paper with water to break down fibers into a slurry with an oatmeal-like consistency. The slurry then goes through screening systems to remove  adhesives, plastic, metal, styrofoam and other material that can't be turned into paper. 

The mix is further refined before it is sprayed out in a sheet that's still about 99 parts water and one part fiber. The sheet, called a ply, is a more than 300-inch wide strip of the raw material to make corrugating medium and linerboard, the two components of corrugated packaging material. Two plys are pressed into a combined sheet and sent through a press to further squeeze moisture out.  

The sheet then goes through dryers to further reduce moisture content, resulting in a finished product with about 7% moisture.

The finished paper is spun onto a massive roll that can hold 65 tons of linerboard or corrugating medium. Sandwich a piece of wavy corrugating medium between two pieces of linerboard and you have the raw materials of a box. 

The company trumpeted the new mill’s sustainability features from the moment it announced the project in fall 2018. 

The project included a switch from coal-fired boilers to natural gas, which cut sulfur dioxide and nitrogen oxide emissions by more than 90%. The mill now produces more paper with lower emissions, resulting in a significant reduction in greenhouse gas emissions per ton of paper produced.

Bauer-Lotto said the company is pursuing additional third-party certification of its sustainability practices. She said a firm is in the final stages of evaluating whether the company's corrugating operations operate on net-zero waste standards. She said the company already recycles and re-uses 95% of the waste that its corrugating operations generate. 

The company also owns and maintains 240,000 acres of forest lands in accordance with Sustainable Forestry Initiative standards and posts its forestry policy online.

Green Bay Packaging also has kept sustainability in mind as it expands its operations in other states.

On Jan. 6, the company announced it would start construction of a 600,000-square-foot corrugating "Super Plant" in Fort Worth, Texas, that is expected to begin operation in the second quarter of 2023. The company has also turned on a 550,000-square-foot box plant in Tulsa, Oklahoma, and it installed high-speed converting lines at facilities across the U.S.

"We look at ways to recycle water, use natural light, improve energy efficiency," Bauer-Lotto said. 

At Green Bay Packaging, the focus on water dates back at least 60 years, Szymanski, the vice president of mill operations, said. In 1963, Green Bay Packaging took its first steps to reduce water consumption. It identified operational ways to reduce consumption and for ways to collect and re-use water. Between the 1970s and 1990s, the company further closed its water loop, introducing a precursor to the new mill's water re-use system. Those investments in the 1990s enabled Green Bay Packaging to end its draws and discharges directly from the Fox River. 

The new mill takes the closed loop system of water use a step further by incorporating extensive, on-site water treatment and wastewater from NEW Water into the process.  

The company  has incorporated recycled mixed paper, such as office paper or newsprint, into production of its boxes. Mixed paper demand has usually been low, meaning some of it could end up in landfills.

"Environmental stewardship has always been in Green Bay Packaging’s DNA. Every generation, we continue to add into our recipe of environmental stewardship," Szymanski, the mill operations vice president, said.

Contact Jeff Bollier at (920) 431-8387 or jbollier@gannett.com. Follow him on Twitter at @JeffBollier.