Keystone pipeline's southern section to open

The construction of the Keystone XL, a pipeline intended to bring hundreds of thousands of barrels a day of oil from Canada’s controversial oil sands to the United States, has been mired in delays as regulators assess its environmental impact, and activists and landowners protest what they see as one of the nation’s largest environmental threats. But the attention surrounding the Keystone XL has mainly focused on its northern component, leaving its shorter southern stretch — which starts operating on Wednesday — and several other pipeline projects out of the limelight.