Don't worry, if the bridge is denied and the facility built anyways (doubtful on economics), the government would be glad to require refrigeration outside the buried line, as a couple sections of the Trans-Alaskan Pipeline had to due in areas where it had to be buried due to Avalanches, but still in permafrost.
http://www.alyeska-pipe.com/PipelineFacts/pipelineengineering.html
See Milepost sections 645 and 649.
Permafrost is overrated. ;)