Nebraska regulators have approved the controversial Keystone XL pipeline, dealing a blow to the nearly decade-long battle to stop the project. On Monday, regulators rejected TransCanada’s preferred route but approved an alternative path for the pipeline, which would link up with an existing network to carry oil from Canada’s tar sands region in Alberta to refineries as far away as the Gulf of Mexico. Opponents say the Keystone XL pipeline threatens to pollute Nebraska’s Ogallala Aquifer while accelerating greenhouse gas emissions from oil extracted in Canada’s tar sands region. Monday’s approval comes only days after, in South Dakota, TransCanada was forced to shut part of its Keystone 1 pipeline after a massive rupture spilled 210,000 gallons of oil into a nearby field.