Minnesota pollution regulators will allow a mega-dairy operation in Winona County to expand without a rigorous study of the greenhouse gases generated by 3,000 additional cows.

The decision last Friday pleased the owners of Daley Farms of Lewiston but disappointed environmentalists, who say the 34,000 tons of greenhouse gases expected to waft out of the dairy are enough to warrant an environmental impact statement (EIS).

Instead, the Minnesota Pollution Control Agency (MPCA) has decided a briefer environmental review will suffice.

Its decision on Daley Farms is the first test of the state's new court-ordered protocols for calculating greenhouse gases emitted by large livestock farms as part of the agency's review of their effects on the environment.

In an interview, farm co-owner Ben Daley said the family feels vindicated. Two MPCA commissioners have now ruled in their favor, Daley said: "We kind of feel like it's just a lot more justification now of our environmental stewardship."

Environmental advocates condemned the agency's decision.

"The MPCA missed an opportunity to help farmers benefit from policies to reduce greenhouse gas pollution," said Aaron Klemz, spokesman for the Minnesota Center for Environmental Advocacy.

The Land Stewardship Project, a group opposed to large-scale farms, said that the MPCA "has ignored sound environmental science and policy."

Barb Sogn-Frank, an organizer with the Land Stewardship Project, said the group has met with MPCA Commissioner Laura Bishop to urge changes in reviewing large livestock farms. It has asked Bishop to direct staff to use their legal authority to require an environmental impact statement.

The expanded Daley Farms operation would produce about 46 million tons of manure a year.

"That's a tremendous amount of manure, and if you're not going to require an EIS for that much manure, why do you even have the regulation?" said Eugene Hansen, a dairy farmer in Winona County.

It's the second time the MPCA decided the Daley Farms expansion doesn't require an EIS.

The first time came last year when the agency issued the water quality permit, but it was challenged and ended up at the Minnesota Court of Appeals. The appellate court kicked the matter back to the MPCA, saying the agency failed to consider the effect of greenhouse gas emissions from the milk operation.

That led to significant changes, and the MPCA has now started to inventory greenhouse gas emissions when it permits large livestock operations that require an environmental review. The state does not require large livestock operations to get air pollution permits.

Leading up to its decision, the MPCA received more than 500 comments, many expressing concern about impacts of the greenhouse gas emissions and urging the agency to do the extensive environmental study. The emissions, mostly methane and nitrous oxide, come from manure and from the guts of cows.

Many commenters also expressed concern about nitrate from the 46 million gallons of manure the expanded operation would produce. Nitrate leaches through the porous karst rock underlying southeast Minnesota, polluting the groundwater. The region's water already has some of the state's highest nitrate levels.

In an interview, Melissa Kuskie, the MPCA's manager of the certification, environmental review and rules section, said that when the agency revisited the environmental review for the expanded Daley Farms, it decided the level of greenhouse gas emissions wasn't enough to warrant an environmental impact statement.

The analysis was "challenging," she said, because there are no state or national air quality standards or guidance for greenhouse gases the agency can use to determine significance. State rules require only the briefer environmental assessment worksheet (EAW) for projects that produce 100,000 or more tons of greenhouse gases per year.

"It's a reasonable conclusion that if they wouldn't trigger an EAW on their own, then they wouldn't warrant an EIS on their own," Kuskie said.

Kuskie said large livestock farms aren't required to get air permits because permitting rules focus on stationary sources like a power plant stack, and not moving animals.

At 34,000 tons of the global-warming gases per year, Daley Farms would be on par with industrial facilities such as Gerdau Ameristeel US Inc.'s mill in St. Paul and Northern Natural Gas Co. in Faribault, according to MPCA emissions data on facilities with air permits. It's the equivalent greenhouse gas pollution from 6,000 cars.

The largest industrial facilities, however, emit far more. Xcel Energy's Sherburne Generating Plant pumps out 14 million tons.

The MPCA's latest decision is not the final word on the Daley Farms project. The agency still has to issue the feedlot's water pollution permit, something expected shortly.

Meanwhile, the Daleys remain locked in a court fight with Winona County over its refusal to lift a cap on the number of cows allowed on farms.

And now, the COVID-19 pandemic has thrown the country's food markets into disarray, with dairy farmers in other states dumping milk.

Daley said the proposed expansion will likely get back on track once the economy regains strength.

"We're just taking this one step at a time," Daley said. "Right now our major focus is on the lawsuit with Winona County."

Correction: Previous versions of this article misstated the amount of manure that the facility is expected to produce.