Over 400,000 gallons according to a federal investigation of the spill in South Dakota farmland.
Officials did not consider last week’s spill in their decision on $8 billion project
It comes just days before an effort to halt the Keystone XL expansion.
The Trump administration has issued a presidential permit for construction to begin.
The new president also reportedly placed a freeze on all new contracts and the agency's current work assignments.
Donald Trump signed two executive orders advancing two controversial oil pipelines, the Dakota Access and Keystone XL.
Bitumen from the oilsands could impact marine ecosystems in 15 ways, scientists say.
The 60,000 Inuit people living in 53 communities throughout the Arctic are already seeing immediate concerns.
Trudeau’s digging in his heels on his environmental policies, but his opponents have been given some powerful ammunition by Trump’s election to the White House.
Facing protests over the environment, Obama killed the Keystone XL pipeline. Now it could be back.
A Motherboard report card.
Standing Rock's Sioux Tribe, the Union of BC Chiefs, and many more Indigenous leaders signed a treaty to prevent expansion of the tar sands.