Oil Sands and the Keystone XL Pipeline: Background and Selected Environmental Issues [February 21, 2013] [open pdf - 1MB]
"If constructed, the Keystone XL pipeline would transport crude oil (e.g., synthetic crude oil or diluted bitumen) derived from oil sands in Alberta, Canada to destinations in the United States. Because the pipeline crosses an international border, it requires a Presidential Permit that is issued by the Department of State (DOS). The permit decision rests on a 'national interest' determination, a term not defined in the authorizing Executive Orders. DOS states that it has 'significant discretion' in the factors it examines in this determination. […] Although some groups have opposed previous oil pipeline permits, opposition to the Keystone XL proposal has generated substantially more interest among environmental stakeholders. Pipeline opponents are not a monolithic group: some raise concerns about potential local impacts, such as oil spills or extraction impacts in Canada; some argue the pipeline would have national energy and climate change policy implications."
CRS Report for Congress, R42611