Iowa landowners have filed a lawsuit against the Iowa Utilities Board over eminent domain use to authorize an oil pipeline that has caused major conflict in the state. 

The landowners — a group of nine — filed the suit with the Northwest Iowa Landowners Association against the board at the Polk County District Court on Friday. William Hanigan, of the Des Moines-based Davis Brown Law Firm, is the attorney representing the landowners.

The lawsuit, Richard Lamb et al v. the Iowa Utilities Board, comes after the Iowa Utilities Board voted 3-0 March 10 to approve construction of the Bakken Pipeline, which would cross through 18 counties in the state.

The lawsuit claims that Dakota Access, LLC, which will construct the pipeline, used eminent domain in a way that violates the Constitution’s Fifth Amendment. Eminent domain is the action of government taking private property for public use, with compensation given in return to the property owners.

The plaintiffs also claim the Iowa board’s actions were in violation of Article I, Section 18 of the Iowa Constitution, which limits the exercise of eminent domain, the Des Moines Register reported.