Super-sized diversion

During last year’s Super Bowl between the Philadelphia Eagles and the Kansas City Chiefs, more than 100 tons of food waste were generated at game-related events, according to the city of Phoenix. To handle the increased organic waste produced by the influx of visitors, the city enlisted the help of Russellville, Arkansas-based Denali Water Solutions.

The partnership between the Phoenix Public Works Department and Denali was part of a larger mission to make the event zero waste, with the goal of diverting 90 percent of waste away from landfills.

While diversion efforts were focused on the city of Phoenix rather than inside State Farm Stadium, where the game took place, the National Football League worked with the stadium to minimize single-use plastic and to ensure discarded food was used for animal feed.

Following the Super Bowl, the city’s Public Works Department reported that it surpassed its diversion goal, with a final diversion rate of 92.6 percent—qualifying it as a zero-waste event.

According to a statement released by the city, 81 tons of material were recycled, while nearly 12 tons of food waste were composted.

The last time Arizona hosted the Super Bowl in 2015, Phoenix set a goal to divert 80 percent of waste from the landfill but ultimately achieved a rate of 73 percent. In 2023, however, the city had the advantage of more robust resources at a Phoenix compost facility operated by Denali.

With the help of a new depackaging machine, the facility can process 15 tons of waste per hour and separate about 95 percent to 97 percent of all trash and food waste.

“The Super Bowl was an interesting test in that we knew the waste stream was going to have a lot of solid waste in it, a lot of single-use containers, and also because we were serving a lot of the parties the city was putting on,” says Samuel Liebl, director of communications for Denali Water Solutions.

“I’m pleased to say that our process and our team did really well. And we proved to ourselves and the city that we were able to process a stream like that and successfully compost it.”

To compost the city’s food waste, Denali’s Compost Facility mixes food waste with green waste and breaks down the materials through aerobic respiration, a microorganic process that takes 40 to 60 days.

Customized approach

The Super Bowl success story is just one example of Denali’s work with large event spaces, such as convention centers, sports venues and concert venues.

Working with some of the largest music venues in the Southwest, the company collects and processes both pre- and postconsumer food waste, which can be challenging. Oftentimes, space constraints can be the biggest challenge, Liebl says.

“One of the biggest challenges that these kinds of spaces have is that their space is limited, so they often do not have the facility space to segregate this material,” he says. “It’s really important for us to be able to work in these complex, compact spaces.”

For a majority of its partnerships, the company works with concession stand kitchens and other food generators.

“We often are doing both pre-consumer and postconsumer food waste,” Liebl says, “working with crews in kitchens to take care of their food scraps and unsold food, as well as food scraps that might be in single-use containers that folks toss after watching a sports game or being at a concert.”

Managing logistics for each operation also is a tricky piece, Liebl says, adding that consistent service and data are two key components of Denali’s service.

“Food waste is often collected in bins at these venues, so it’s key for us to have reliable, consistent service in picking up those bins,” he says. “And when we pick them up, we also clean them; our trucks are equipped with scales, so we are capturing that weight data that we’re able to provide back; and we’re often building off of our experience serving thousands of grocery stores across the country.”

For a large concert venue in the Phoenix area, Liebl says Denali deploys 10 64-gallon bins around the venue’s concession stands. But because each venue is different, consumer behavior and expected tonnages can vary greatly.

To gauge these factors, Denali often will perform pilot projects with customers before entering long-term service agreements. During the pilots, the company will host waste services for a handful of games or shows to find specific pain points, expected waste streams and the best end markets for that waste, such as animal feed or compost.

Growing end markets

Operating 36 composting facilities across the U.S. and with plans to expand its depackaging services to 40 more cities over the next year and a half, Denali aims to divert as much waste as it can.

The company’s use of depackaging technology has been at the center of these efforts, Liebl says, describing the machines as a “game-changer” for the management of organics. According to the company’s website, the depackaging machines use a system of augers, drums, grinders and screens to separate plastic, cardboard and other forms of packaging from their organic contents.

Liebl says Denali sources its machines from several different brands, and the company has found each has its strong suits.

“Some are better at handling wetter material; some are better at handling drier material. And we’ve gotten really good at operating them, so they work quite well,” he says.

In Phoenix, the company runs its depackaging machines nearly every hour of the day, Liebl adds. Prior to employing the depackaging technology, he says, “things were labor-intensive to separate and, therefore, prohibitively expensive to recycle.”

“Now, that’s not a barrier, and we find food waste is a great feedstock for making compost,” he adds. “In some cases, it can go to anaerobic digesters. If it is a stream where it does not include animal products, then it’s often a great source for animal feed.”

In states such as Texas, Arizona and California, Denali processes products from bakeries, which can be blended with other agricultural byproducts to create high-value animal feed often used by dairies.

The company also prioritizes local circularity, with most finished compost remaining in the city in which its components were generated.

“The circularity is exciting,” Liebl says. “What’s kind of cool is if you’re in Phoenix, for instance, and you go to the store and you buy a bag of compost or high-nutrient soil products, there’s a good chance the compost contains nutrients from a sports event or concert you might have gone to.”

The author is associate editor of Waste Today and can be reached at hrischar@gie.net.