MORRIS, MINN. – The Fehr family thinks big. Members have built their Riverview Farms LLP into the largest single milk producer in Minnesota, with five massive dairy operations that house more than 34,500 cows.

But when they proposed a new $55 million dairy feedlot last year, a panel of citizen regulators balked because of environmental concerns, and now their standoff has rural Minnesota asking: How big is too big?

“We used to be concerned about 1,000 head in one location,’’ said James Riddle, a member of the Citizens’ Board of the Minnesota Pollution Control Agency. “Now it’s 10,000 head.’’

The jolt didn’t stop the Fehrs, who quickly secured two other sites for major expansions. But it angered some of Minnesota’s most powerful farm organizations and ended a decade of relative calm in the battle over large-scale confinement of farm animals.

In southwestern Minnesota, the town of Hendricks has sued to stop a 4,000-cow dairy operation proposed just across the border in South Dakota. In Dodge County, citizens are challenging the proliferation of huge swine barns. At the Capitol, feedlot operators are asking for an exemption from state law on neighbors’ nuisance claims.

Common to all the battles is a concern that the huge feedlots will deplete local groundwater, spill manure into waterways and produce gassy odors that spoil rural living. Neighbors and conservationists also believe that outsized livestock operations are squeezing out smaller, more diversified farms that they say are healthier for the land.

22 hours a day

At a typical Riverview dairy, multiple milk trucks park at loading doors around the clock, accepting instantly chilled milk as it’s pumped from the cows.

The milking parlors run 22 hours a day — including 80-stall, rotary units that circle just slowly enough for cows to walk into the stanchions, get milked, and back themselves out in one spin.

The raw milk is trucked to commercial cheese plants in Minnesota and North Dakota — more than 56 semi-loads of milk per week from Riverview’s biggest plants.