Last year, Ben & Jerry’s acknowledged that its sourcing practices weren’t perfect. “As we have been evaluating our current dairy supply chain, and while we have worked diligently over the past 7 years to improve farm practices, we fully acknowledge that it is not where we would want it to be,” the company said in a statement addressing the dairy industry’s range of deleterious effects. It said it was “actively exploring ways” to stop “operating in the same broken system.”

But the OCA takes issue with the brand’s continued use of environmentally friendly imagery. In its lawsuit, the group said that lab tests it commissioned show some Ben & Jerry’s flavors, including favorites such as Phish Food and Chocolate Fudge Brownie, contain low levels of glyphosate, a widely used pesticide. Ben & Jerry’s has said it was “concerned, but not totally surprised” that the pesticide was there, and committed to “no more ingredients using glyphosate-dried crops” and creating a new line made with 100 percent organic dairy.

The “big picture goal is for Ben & Jerry’s to do the right thing.”

Colby said he has been lobbying Ben & Jerry’s for decades to change its sourcing practices, even taking them on drive-by tours of various Vermont dairy farms to show barrels of pesticide, manure pits, dilapidated migrant labor housing and green foamy, cyanobacteria-infected water in Lake Carmi. He goes out of his way not to blame local farmers, though, arguing that they are forced to cut corners to keep afloat.

Nevertheless, OCA’s lawsuit faces an uphill battle, according to Brent Johnson, a class action defense lawyer. At the center of the complaint is the argument that Ben & Jerry’s isn’t living up to its promises of environmental stewardship and humane animal husbandry. The problem, he said, is that these promises are nebulous.

“It’s unspecific, and that is probably what will cause the biggest problem for the plaintiff in this case,” said Johnson, a partner at the law firm Holland & Hart.

The presence of glyphosate, he adds, doesn’t necessarily prove that Ben & Jerry’s isn’t environmentally responsible. “I think that’s a real stretch, based on the omnipresence [of the chemical] in our food supply chain,” he said.

The plaintiffs do have at least one important fact on their side, he said: “If it’s true that St. Albans’ mixes milk production, and some don’t qualify as a Caring Dairy under the standards articulated by Ben & Jerry’s, that’s to me the plaintiffs’ best case.”

Katherine Paul, of the OCA, said the “big picture goal is for Ben & Jerry’s to do the right thing.”

“Imagine if they took some money and instead of using it for misleading advertising, helped Vermont dairy farmers transition away from conventional farming,” she said. But “short of that,” she said, we want them to “stop misleading consumers.”