Environmental groups and several residents sued Texas-based Natural Prairie Dairy and the Army Corps of Engineers in 2019, accusing Natural Prairie Dairy of violating the Clean Water Act when it installed drainage tiles and filled ditches during the Newton County farm’s construction.

The Hoosier Environmental Council and the Indiana Audubon Society said Natural Prairie Dairy did not contact the Army Corps to determine if the land and ditches were subject to federal regulation until nearly two years after the work was completed.

Kim Ferraro, senior staff attorney for the Hoosier Environmental Council, said the Army Corps “summarily concluded that the land is not a wetland, and the ditches were not jurisdictional waters — effectively legitimizing Natural Prairie’s activities after-the-fact and eliminating the need for Natural Prairie to obtain a federal permit to build” the concentrated animal-feeding operation.

In last week’s ruling, U.S. District Judge Damon Leichty in South Bend found that the Army Corps’ administrative jurisdictional determination was “arbitrary and capricious,” because it was not supported by facts in the administrative record.

He sent back the decision to the Army Corps for further consideration, The (Northwest Indiana) Times reported.

The dairy farm, which includes 4,350 cows and a 9-acre waste lagoon, was built in the Kankakee River basin in “one of the most ecologically sensitive and historically significant areas in the state,” the environmental groups said.

That area was part of the Grand Kankakee Marsh, which once stretched nearly a million acres across parts of northern Indiana and Illinois before it was drained for agriculture. The vanished wetland is often referred to as the “Everglades of the North.”