17 percent Keystone XL Pipeline map 830,000 barrels Keystone XL pipeline http://www.npr.org/2014/11/17/364727163/... pipeline NPR pipeline traditional oil drilling presidential permit Keystone XL pipeline Keystone XL greenhouse gas NPR Overview pipeline designed to carry 830,000 barrels Keystone XL pipeline NPR Overview pipeline failed $75 per barrel Keystone XL pipeline pipeline report three years ago 17 percent npr.org 830,000 bpd 830,000 barrels of crude XL pipeline $75 per barrel