The U.S. State Department must halt plans to expand an oil sands pipeline route from Canada to Wisconsin until possible environmental harm has been closely studied, several green groups said in a lawsuit filed on Wednesday. An Enbridge Inc proposal for its Line 3 pipeline from Alberta to Wisconsin is part of a $7.5 billion upgrade on its system that would help oil sands producers in Western Canada reach refineries in the Gulf Coast and elsewhere. Such cross-border projects typically require State Department approval, but officials told the company in June that the most thorough review is not needed in the case of this expansion plan. A federal court should halt the project until there has been “a review of the pipeline’s environmental impacts,” according to the suit, which was filed in federal court in Minneapolis by eight activists groups, including Sierra Club and Center for Biological Diversity. Green groups want a thorough review akin to the ongoing, years-long State Department examination of the Keystone XL pipeline proposal - a project that would carry as much as 830,000 barrels per day of oil sands crude per day and which has become a political lightning rod. “Enbridge believes that the State Department has acted lawfully,” said a representative for Enbridge, Canada’s largest pipeline operator.