Iowa regulators have rejected a request by two environmental groups to revoke a state permit and shut down oil shipments on the $3.8 billion Dakota Access pipeline.

The Iowa Utilities Board said Friday it was clear a federal court has not withdrawn the pipeline's authority to operate and the groups' motion was based on an incorrect premise. The decision was signed by Chairwoman Geri Huser and board member Nick Wagner.

The Sierra Club of Iowa and the Science and Environmental Health Network had claimed that a recent ruling by U.S. District Judge James Boasberg in Washington, D.C., invalidates the company's Iowa permit. They noted that the Iowa permit was conditioned on Dakota Access obtaining all necessary state and federal authorizations for the project.

The pipeline began transporting crude oil on June 1 from North Dakota's Bakken oil patch to a distribution hub at Patoka, Ill. It crosses diagonally through 18 Iowa counties and has a capacity to ship about 520,000 barrels of oil daily.

Lawyers representing the Dakota Access had filed a resistance with the state board that accused attorneys for the anti-pipeline groups of making statements so "shockingly dishonest" that the board should consider whether it can sanction attorneys who misrepresent facts to state regulators.

The Iowa Utilities Board sided Friday with Dakota Access' lawyers. "The board will deny the motion to revoke. The D.C. court order is clear that the permit has not been revoked at this time," the regulators said.

Boasberg's 91-page decision concluded the U.S. Army Corps of Engineers complied with some, but not all, requirements of the National Environmental Policy Act before it issued a permit allowing the pipeline to run under the Missouri River in North Dakota. But the judge did not order Dakota Access to immediately stop transporting oil, saying that was a separate question he would consider after further legal arguments.

Wally Taylor of Cedar Rapids, a lawyer for the Sierra Club, and Carolyn Raffensperger of Ames, a lawyer and executive director of the Science and Environmental Health Network, both said Friday they were disappointed but not surprised by the state board's decision.

"They just don't seem to want to admit their mistake," said Taylor, whose organization has mounted a challenge the board's previous approval of the pipeline project before the

The Iowa Supreme Court is also weighing an appeal by a group of landowners over the Iowa Utilities Board's decision to authorize the use of eminent domain to obtain access to their farmland for the pipeline route.