Standing Rock Sioux Tribe files new lawsuit over DAPL

Tribe says case against Army Corps triggered in part by new engineering report on water crossing

The Standing Rock Sioux Tribe on Monday filed a new lawsuit against the U.S. Army Corps of Engineers arguing that the Dakota Access Pipeline is operating illegally and must be shut down.

The tribe has long opposed the pipeline, also referred to as DAPL, due to concerns that it violates the tribe’s sovereignty, endangers sacred cultural sites and threatens to pollute the tribe’s water supply.

The Army Corps of Engineers has jurisdiction over the section of the pipeline that passes under Lake Oahe — a reservoir on the Missouri River — roughly a half-mile upstream from the Standing Rock Reservation.

The tribe in a 34-page complaint filed in U.S. District Court for the District of Columbia argues the Army Corps flouted federal regulations by allowing the pipeline to operate without an easement, sufficient study of possible environmental impacts or the necessary emergency spill response plans, among other alleged violations.

“We are fighting for our rights and the water that is life for Oceti Sakowin tribes,” Standing Rock Sioux Tribe Chairwoman Janet Alkire said during a news conference the afternoon of Indigenous Peoples Day.

The Army Corps of Engineers did not immediately respond to a request for comment.

The more than 1,000-mile-long pipeline carries crude oil from the Bakken oil fields of northwest North Dakota to Illinois, and has been operating since 2017. Its pathway includes unceded land recognized as belonging to the Sioux Nation under an 1851 treaty with the U.S. government.

The lawsuit was triggered in part by a 2024 engineering report that raised questions about the construction of the pipeline crossing below Lake Oahe, representatives of the tribe said Monday.

The report calculated that up to 1.4 million gallons of bentonite clay-based drilling mud used in the horizontal directional drilling process was not fully accounted for in construction records. The report notes that there is no clear indication where the fluid migrated, but that it could have seeped into the surrounding soil.

“The Corps has failed to act and failed to protect the tribe,” Alkire said of the report’s findings. 

The report was prepared by engineering consulting firm Exponent for environmental advocacy group Greenpeace as part of an ongoing lawsuit brought by pipeline developer Energy Transfer. Greenpeace commissioned the report to defend itself against Energy Transfer’s allegations that Greenpeace defamed the pipeline during its involvement in protests against DAPL in 2016 and 2017.

Energy Transfer has requested that the report be tossed from the case, arguing that the evidence is not reliable. The company did not immediately respond to a request for comment late Monday.

A regulator at the North Dakota Department of Environmental Quality confirmed some drilling mud breached containment during construction, but said the substance never reached the lake bed and is not toxic.

“Bentonite’s not a contaminant of concern,” Bill Suess, who manages the Department of Environmental Quality’s Spill Investigation, told the North Dakota Monitor. He noted that the clay is native to the soil. The agency didn’t feel the need to formally investigate the matter, Suess said.

“This is something we see happening virtually on every horizontal boring we see,” Suess said. “It happens. It’s not a major issue.”

The pipeline is about 95-115 feet below the bottom of the riverbed at the Lake Oahe crossing, Energy Transfer has said.

A public affairs official with the Army Corps of Engineers Omaha District last week told the North Dakota Monitor that it was not aware of such an incident.

Construction inspection reports filed with the North Dakota Public Service Commission identified no deficiencies at the Lake Oahe drilling site on Jan. 20, 2017, or Feb. 23, 2017.

Standing Rock’s complaint also emphasizes that the Dakota Access Pipeline has still been allowed to operate despite that it no longer has an easement authorizing it to cross under Lake Oahe.

The Army Corps approved the easement in 2017, but a federal judge later revoked it in 2020, finding that the Corps violated environmental law by granting it without properly researching the possible environmental impacts of the pipeline.

U.S. District Court Judge James Boasberg instructed the Army Corps of Engineers to complete a more thorough environmental impact study, which is still in the works. (Boasberg also ordered the pipeline to stop operating, though that demand was ultimately overturned by an appellate court.)

A draft version of the environmental impact study released by the federal agency last year acknowledges that the construction method used to bore DAPL’s pathway under Lake Oahe — horizontal directional drilling — is vulnerable to drilling fluid unintentionally migrating to the surface or seeping into other locations.

The document notes the drilling fluid is “benign” but can cause some environmental impacts.

The draft said no such incidents were observed during DAPL’s construction.

Energy Transfer claims on its website that, in accordance with federal law, it always has response plans in place to properly handle any drilling mud displacement.

“If at any time during the drilling process an inadvertent return is suspected, the construction team immediately works to contain and remove any drilling mud that is released during (horizontal directional drilling) activities,” the website says.

Regardless, Standing Rock representatives said Monday that enforcement actions taken against Energy Transfer related to other pipeline projects are enough reason to shut down DAPL.

The Environmental Protection Agency in 2022 proposed a ban on Energy Transfer entering into any future contracts with the federal government, the tribe noted.

Energy Transfer is not qualified to have an easement if it is debarred from federal contracts, Standing Rock argues in the complaint.

The ban was related to a criminal pollution case against Energy Transfer for two pipelines in Pennsylvania. Violations alleged in the criminal case included that Energy Transfer had used unapproved additives in the drilling fluid used to construct one of the pipelines. The company was convicted of environmental crimes under Pennsylvania law.

For this reason, Standing Rock wonders whether the drilling fluid used to bore under Lake Oahe truly contained no toxins.

“That’s a question the tribe has — what was in the drilling fluid?” Don Holstrom, an environmental consultant for Standing Rock, said Monday.

Standing Rock has ground and surface water testing programs, but it lacks adequate funding for consistent, real-time water monitoring, said Peter Capossela, an attorney representing Standing Rock in the suit.

“In a sense, DAPL is an unfunded mandate on the tribal government,” Capossela said during the conference.

Standing Rock also accuses the Army Corps of illegally allowing the pipeline to operate despite evidence that construction of the pipeline led to damage to Native burial sites near Standing Rock in 2016.

Energy Transfer has denied causing any damage to burial or other cultural sites, and maintains that it complied with all relevant regulations.

Additionally, the complaint accuses the Army Corps of neglecting to require Energy Transfer to share its emergency response plans with Standing Rock in the case of a spill under Lake Oahe.

Standing Rock claims that Energy Transfer has only provided redacted versions of the documents.