— by Michael Riordan for Sightline

This article is part of the series “The Risk of Northwest Oil Spills”

Every week another barge or tanker traverses the narrow straits through the San Juan Islands north of Seattle, bearing a cargo of tar-sands crude or other heavy oils from Canada, headed for refineries in Washington and California. But the Kinder Morgan Trans Mountain Pipeline Expansion Project approved in late 2016 by the government of Canadian Prime Minister Justin Trudeau threatens to make such transits daily occurrences, thus increasing many-fold the chances of a major oil spill in the Salish Sea and other Pacific Northwest waters.

The $7.4 billion Kinder Morgan project would add another pipeline alongside one that already extends from Edmonton, Alberta, to the Westridge Terminal in Burnaby, near Vancouver, British Columbia. It would increase the system’s capacity from 300,000 to 890,000 barrels per day. Most of the additional oil would be tar-sands crude that would be loaded onto another 348 tankers plying the Salish Sea every year.

In order to flow through pipelines, the viscous, tarry bitumen mined in Alberta must be diluted with light hydrocarbons like benzene or naphtha—and is thus called diluted bitumen, or “dilbit” for short. If the dilbit were to be spilled from a tanker into the Northwest’s inland sea, a portion of it might be corralled and removed by prompt action of the Canadian or US Coast Guard and other responders.

But not all of it. (To read the full article, go to https://www.sightline.org/2017/05/22/the-tar-sands-threat-to-northwest-waters/ )