The Supreme Court ruled unanimously on April 22, 2026, that a lawsuit over Michigan’s attempt to shut down the Line 5 pipeline must stay in state court. The 18-page decision was written by Justice Sonia Sotomayor. The case was sent back to Michigan state court after the justices agreed that pipeline company Enbridge had missed a key legal deadline.
Line 5 is a 70-year-old oil pipeline with a capacity of approximately 540,000 barrels of crude oil per day. It runs from Wisconsin to Ontario, Canada, crossing four miles beneath the Straits of Mackinac under the Great Lakes.
The legal fight started when Michigan Governor Gretchen Whitmer signed an order in 2020 revoking the easement that allowed the pipeline to cross under the straits. The Michigan Department of Natural Resources backed that move. The state then filed a lawsuit to shut down the underwater section of the pipeline.
Enbridge tried to move the case from state court to federal court. But there’s a strict rule that says companies must file a removal notice within 30 days. Enbridge waited 887 days before filing. That’s nearly two and a half years past the deadline. Despite that delay, Enbridge initially won in federal court. The Sixth Circuit Court of Appeals reversed that decision and ordered the case back to state court. The Supreme Court’s ruling backed up the appeals court.
Enbridge had argued that federal law should control the case. The company pointed to a 1977 treaty between the U.S. and Canada that prevents states from stopping the flow of hydrocarbons across the border. Enbridge said that made the dispute a federal matter. The Supreme Court didn’t buy that argument, at least not as a reason to allow the late filing.
The ruling’s a win for Michigan officials and groups that want the pipeline shut down. It keeps the case under state jurisdiction. Enbridge’s effort to have a federal judge handle the conflict with the state order has now failed. The legal battle is expected to continue in Michigan state courts. Michigan Attorney General Dana Nessel, who filed suit in 2019, argued that the pipeline posed a risk of a catastrophic spill into the Great Lakes and that Enbridge had violated the terms of its state lease. The pipeline itself stretches 645 miles between Wisconsin and Ontario, Canada, making it a critical cross-border energy corridor. The outcome carries broader implications amid ongoing debates over pipeline safety regulations under the Trump administration.
References
- https://www.morningstar.com/news/dow-jones/2026042211281/supreme-court-rules-against-enbridge-in-michigan-effort-to-close-line-5-pipeline-opis
- https://www.eenews.net/articles/enbridge-loses-supreme-court-bid-to-transfer-michigan-pipeline-fight/
- https://www.youtube.com/watch?v=dIAxl_6Vj8s
- https://fox11online.com/news/state/enbridge-line-5-lawsuit-united-state-supreme-court-michigan-energy-crude-oil-natural-gas-superior-wisconsin-sarnia-ontario-great-lakes
- https://www.michiganlcv.org/supreme-court-decision-keeps-line-5-legal-battle-in-michigan-courts/
