Under protests from a major pork producer, state regulators are reconsidering a promise they made to a group of determined Goodhue County residents last year to test for excessive odorous fumes around a hog farm — the first time the state had agreed to conduct such monitoring since 2009.

It's a new escalation in the ongoing conflict between Minnesota's growing hog industry and rural neighbors who find themselves living next door to massive new livestock feedlots. This time, the citizens group took matters into its own hands by conducting air measurements, submitting them to state regulators and meeting with Gov. Mark Dayton's staff to present their case that the facility is violating air standards.

"This is their job," said Kristi Rosenquist, one of the frustrated residents in Zumbrota township who have been fighting expansion of Kohlnhofer Farms in Goodhue County.

But in late April, the owners of the hog farm pushed back on the Minnesota Pollution Control Agency (MPCA), saying the state can't conduct the air monitoring because it wouldn't be following its own rules.

"This is a complete game-changer when we have 20 years of protocol," said Jack Perry, the attorney for Kohlnhofer.

Officials from the MPCA declined to address what they said were legal questions related to the dispute, saying that the matter is still under review by state attorneys.

But e-mails, letters and other documents provided to the citizens group show that state regulators have struggled among themselves over how to enforce a complex set of air quality regulations — and that, although Minnesota has some of the most stringent feedlot rules in the country, its program for monitoring air contaminants such as hydrogen sulfide has fallen into some disarray.

Until Rosenquist and her neighbors complained, for example, a critical piece of equipment the MPCA uses to monitor air quality had not been used often enough to remain in working condition. It has since been replaced, and the equipment is now being tested.

The dispute has also created a bit of a rift between two branches of the agency — one that manages feedlots and one that monitors air quality — over how to respond to questions raised by the governor's office.

"The focus is on air monitoring and not on our broader feedlots oversight system," said Frank Kohlasch, manager of the state's air monitoring division in an e-mail to his superiors at the MPCA. "The agency has explicitly not placed significant focus on air monitoring at feedlots due to the special treatment for this constituency of facility owner/operators."

4,700 hogs on giant feedlot

Agency spokesman Ralph Pribble said Kohlasch and other agency managers were unavailable to discuss the e-mails or the dispute. He said, however, that Kohlasch was likely referring to statutory protections created by the Legislature for the livestock industry.

The dispute began in 2016 when the Kohlnhofer petitioned Goodhue County to build a 4,700-hog facility in Zumbrota Township, one of several large feedlots they operate in southeast Minnesota.

During public hearings, Rosenquist said, state pollution officials assured residents that they would enforce Minnesota's standards for air pollution from hydrogen sulfide, one of the components that creates the stench from manure, which is often stored in huge quantities under a feedlot's barns. In addition to polluting the air, hydrogen sulfide can also be a human health hazard, and the state has another limit for that reason: the air concentrations cannot exceed an average of 7 parts per billion over a 13-week period.

But the neighbors were doubtful of the company's emission control predictions and last summer joined up with the Land Stewardship Project, a sustainable farming advocacy group, to monitor the air around Kohlnhofer's other operations.

What they said they found were possible violations of both of the state's hydrogen sulfide standards, so they asked the state to step in. In early December, MPCA Commissioner John Linc Stine wrote to them and said the agency's short-term monitoring had not found any likely violations of the air quality standard, but it did find levels that could exceed the health risk limit. A definitive ruling would be determined by long-term monitoring — 24 hours a day over several months with more sophisticated equipment.

That, Stine said, would be done in the spring. But so far no monitoring has been done.

In letters and meetings, Perry, Kohlnhofer's attorney and a lobbyist for the state's pork industry, objected to the agency's plan. He said it doesn't comply with the protocols laid out in state rules, policies and past practice. Perry said long-term monitoring of a facility is permitted only if short-term tests show hydrogen sulfide levels exceed air quality standards — which wasn't the case at the Kohlnhofer facilities. And measurements for the health standard have to be taken at a complainant's home, not the property line of the hog facility, which is where they were taken at Kohlnhofer Farms. Finally, he questioned whether the state even has the authority to enforce the health standard.

"It's really, really important to the industry," he said in an interview. "If you change the rules midstream, everyone is a loser."

Rosenquist, however, said that for her and other rural residents, the more important question is whether the state even tries to enforce the standards that are designed to protect them and their way of life.

Because it's clear to her, she said, that for the last 10 years the state hasn't.