"Building the Keystone XL pipeline would lead to more manmade light and noise in sparsely populated regions, which may harm natural resources, wildlife and visitors to national parks, the U.S. Interior Department said."
"In comments the agency submitted to the State Department as part of an environmental review of the project, Interior warned that TransCanada Corp., the project’s builder, isn’t adequately dealing with risks to 'cultural soundscapes' and 'high quality night skies.'
'The cumulative effects of the project could adversely impact the quality of the night skies and the overall photic environment,' Willie R. Taylor, director of the office of environmental policy at Interior, wrote in a letter on April 29. The State Department posted the letter on its website this week as it releases 1.2 million comments received about the project."