Target Field, looking to bolster its claim to the title of greenest ballpark in America, has swapped out most of its disposable food containers for compostable products that can be turned into dirt.

Large venues like sports stadiums are notorious for the volume of trash produced by its hungry and thirsty fans. In an effort to reduce waste, the Minnesota Twins this season became the second major league baseball team to partner with Eco-Products, a Boulder, Colo., company that makes alternative options to paper and plastic packages.

The main ingredient, called Ingeo, is a resin-based product made by Minnetonka-based NatureWorks, which is 50 percent owned by Cargill.

"We had had a number of discussions on the topic for a number of years," said Laura Day, executive vice president of business development for the Twins. "We were a bit concerned because most initiatives of this magnitude are really an effort of changing consumer behaviors."

Bottles and cans were already recycled at Target Field. But introducing compostable containers, the Twins organization hopes to improve its waste diversion rate from last year's 73 percent to its ultimate goal of 90 percent.

NatureWorks got its start in the 1990s as a Cargill R&D project looking to turn cornstarch sugars into something useful and marketable. The result was Ingeo, a material made by fermenting the sugars. Once liquefied, the substance is formed into hard pellets that are sold to a variety of manufacturers, including food-service packaging companies like Eco-Products. These firms then turn the pellets into consumer products ranging from diapers to mobile phone cases — some of which are compostable.

The three-year partnership will supply Target Field with hundreds of thousands of cups, plates, trays, eating utensils and straws. And because they are made from organic substances, these disposable products can mix with food scraps and other organic waste.

In fact, the more food scraps the better, says Wendell Simonson, vice president of marketing at Eco-Products. That goopy nacho cheese and leftover hot dog bun actually aids in the product's breakdown process.

"Then it's easier for the fan because everything except bottles and cans go in the same bin," and the fans don't have to clean the product, said Simonson.

Early results suggest the fans are adapting to the process. All compostable products are disposed in a large bin with picture and word labels. When the bins are emptied, the contents are taken to the basement of Target Field where people hired to sort the trash check to make sure non-compostable plastics haven't been thrown in.

"The streams have been very clean," said Day. "Based on that, I think our fans are indeed adapting."

These pure streams are then taken to an off-site composting facility that offers the two things needed to help breakdown the wares — water and moderate heat.

This final step is key, says Steve Davies, director of public affairs for NatureWorks. If thrown into a landfill, composting products are as useless as plastic bags.

"Landfills are designed to be inert, to basically be tombs," Davies said. "Things that would naturally degrade won't in a landfill, and that's why people are trying to stop things from going to landfills."

Ballparks can be ranked by a variety of green initiatives that offer bragging fodder for different venues. For instance, the St. Paul Saints point to solar panels and rainwater reuse at CHS Field in its claim to greenest ballpark honors while the Minnesota Twins tout Target Field's LEED certification. Both stadiums are now using recyclables and organic composting.

Kristen Leigh Painter • 612-673-4767