A U.S. appeals court on Friday denied Dakota Access LLC"s petition for a rehearing of a court decision that canceled a key permit for its oil pipeline and ordered an environmental review, court documents show. The decision by the United States Court of Appeals for the District of Columbia means the Dakota Access Pipeline (DAPL) technically is still trespassing on federal land because it does not have a permit to cross under the Dakotas" Lake Oahe. The line is currently operating indefinitely but will be reassessed once the environmental review of the line is completed in March 2022. The 570,000 barrel-per-day DAPL began operating in mid-2017 but drew controversy during construction as Native American tribes and activists protested its route under Oahe, a critical drinking water source for the tribes. Last summer, a U.S. district court judge threw out a federal permit for the line to operate under the lake and ordered an environmental review for that section of the pipeline. A three-judge panel at the circuit court in January upheld the lower court"s decision to vacate the permit and require the review. The pipeline"s operators wanted the circuit court to reconsider the panel"s decision, but the court unanimously denied the request. The decision leaves only the U.S. Supreme Court for Dakota Access to oppose the environmental review and permit denial, but it"s not certain the nation"s highest court will take up the case. "This is a pretty definitive statement that the legal issues in this case do not warrant attention from the Supreme Court," said Earthjustice attorney Jan Hasselman, who represents the Standing Rock Sioux in the case. "Here, not only didn"t we see dissents, not a single judge called for a vote." A spokeswoman for Energy Transfer LP (ET.N), DAPL"s majority owner, declined to comment on current or pending legal matters. DAPL is the largest pipeline out of the Bakken region, which produces about 1 million barrels of crude per day in North Dakota and Montana. If the pipeline were forced to close, the state of North Dakota estimates production could fall by 400,000 bpd temporarily. Once the U.S. Army Corps of Engineers completes its environmental review, a decision will be made on whether to issue a new permit for the pipeline. On Friday, the Native American tribes that brought the lawsuit argued to the District Court that Dakota Access pipeline"s operators exaggerated the economic impact from shutting down the pipeline and the pipeline’s safety has never been evaluated as the law requires. read moreThe operators of the Dakota Access oil pipeline (DAPL) argued to a federal court on Monday that the system"s shutdown would be even more harmful than previously anticipated, in their final plea to keep the line open after a key permit was scrapped. The operators, led by Energy Transfer (ET.N), told the U.S. District Court of the District of Columbia that an "immediate economic shock" would occur if the line were shut during a court-ordered environmental review. The company"s revenue losses while closed would be 10% higher than previously projected, at between $3.44 million and $4.28 million per day, they said. The 570,000 barrel-per-day (bpd) DAPL pipeline began operating in 2017 but has been locked in legal battles with Native American tribes and activists since before the line started construction. Last year, the D.C. Court canceled a permit allowing DAPL to operate below the Lake Oahe waterway in North and South Dakota. DAPL is the biggest system carrying oil from the Bakken shale basin of North Dakota and Montana. The Court also ordered the U.S. Army Corps of Engineers to conduct an environmental review, expected to be completed in March 2022, that will determine whether the line remains permanently open. The current filing is hoping to sway Judge James Boasberg to keep DAPL open during that process. The tribes argue that DAPL endangers their water supply from Lake Oahe. Dakota Access says the line meets the energy needs of the Midwest and Gulf Coast and provides for the economies of North Dakota and other states. The Corps of Engineers has not sought to shut the line. The tribes must tell the court by April 23 whether they will respond to DAPL"s filing. A decision on the tribes" request for thThe U.S. Army Corps of Engineers on Friday said it will allow Energy Transfer LP’s (ET.N) Dakota Access oil pipeline to keep running without a federal permit, frustrating activists who wanted the line shut after a key environmental permit was scrapped last year. The pipeline has been the flashpoint for a years-long legal battle between Energy Transfer and several Native American tribes who say it could contaminate drinking water supplies. Native tribes led by the Standing Rock Sioux won a victory last year when Judge James Boasberg of the U.S. District Court of the District of Columbia vacated a federal permit allowing the line to run under Lake Oahe and ordered a new environmental review. The Corps could have shut DAPL during its review process, but instead deferred to the courton Friday. Boasberg gave the pipeline"s operator until April 19 to make its case for keeping the line flowing before he issues a ruling. Environmental activists and tribal representatives decried what they called the latest in a series of decisions that violate the rights of Native Americans. "It"s the continuation of a terrible history that we believed was going to change," Earthjustice lawyer Jan Hasselman, who represents the Standing Rock Sioux, told the court. "So we are really disappointed to hear this news from the Army Corps." Hasselman said at a press conference following the hearing that he and the Standing Rock Sioux would continue to appeal to the Army Corps and the court to order the line shut while an environmental impact statement (EIS) is produced. He expected a decision by the court on the tribes" request for a shutdown order sometime in May. The Army Corps is expected to produce an EIS by March of 2022, said Corps attorney Ben Schifman. "The Corps is proceeding with the EIS process ... but at this time has not taken any additional action," Schifman said. DAPL is the biggest pipeline transporting crude out of North Dakota, shipping up to 570,000 barrels of North Dakota"s crude production daily. Dakota Access proponents say a shutdown would increase reliance on crowded rail lines and smaller pipelines and hamper transport of crude from the Bakken region, where more than 1 million barrels are produced daily. "Its continued operation is essential to the American economy, as well as our energy security and our national security interests," Craig Stevens, spokesman for pipeline advocates GAIN Coalition, said in a statement. Energy Transfer shares closed up 2% on Friday. The company was not immediately available for comment. The Army Corps decision to let the Dakota Access Pipeline (DAPL) continue to run came despite mounting pressure on the White House, led by environmental and Native American advocates, to close the line during the environmental review.