Even harder if it were dilbit. The problem lies partly in bitumen’s stickiness — in air, it dries like varnish on rocks and other surfaces — and partly in its weight. Conventional crude is lighter than water; it mostly floats to the surface, where it can evaporate and be skimmed. Straight bitumen is denser; it sinks to the bottom and penetrates sediments and substrates. Diluted bitumen has about the same density as water, which makes it hang in the water column.

The industry maintains that dilbit is so thoroughly homogenized, the bitumen and diluents can’t separate. That may be true when it's contained, but it didn’t hold in July 2010 when an Enbridge pipe carrying dilbit ruptured near Marshall, Michigan, causing the costliest pipeline spill in U.S. history.

As at Burnaby Inlet, the pipeline operators didn’t heed initial warning alarms, nor calls from fume-shocked residents — for 17 hours. An estimated 840,000-plus gallons of dilbit spilled into a marsh and drained into a tributary creek and, a few days later, the Kalamazoo River. In the water, the heavy bitumen and light diluents separated and, respectively, sank and evaporated. The result is a cleanup nightmare from which the Michigan waterways and their human neighbors still haven’t recovered; $700 million later, Enbridge and various agencies still haven’t gotten the stuff off the bottom.  

Alarming as the Michigan spill was, a tanker spill in Haro Strait, with its fast currents, ever-busier vessel traffic, and rich biota, could be much bigger and nastier. But Kinder Morgan can simply say “not our problem” to crossborder marine concerns; once the oil leaves its tanks, it’s the shipper’s responsibility. The U.S. government, Washington state and island and peninsula counties have no say over the permitting or construction of the pipeline.

Kinder Morgan has spent the fall and winter conducting "information sessions" (described by critics as “focus groups,” “dog and pony shows” and “opposition research") in 31 Canadian communities along the pipeline and tanker routes. It’s declined to visit their counterparts across the international border: “We need to get through [the B.C. tour] before we’re sure what’s next,” explains Davies.

State and federal authorities here are scrambling to figure that out — and to determine whether their spill prevention and cleanup resources could come anywhere near handling a quintupling of Canadian tanker shipments. Sen. Maria Cantwell attached a provision to the Coast Guard funding reauthorization bill passed last month that directs the Coasties to perform risk and cost-benefit analyses of the tar-sand oil shipments, a comparison of pertinent U.S. and Canadian regulations, and recommendations for preventing and cleaning spills. It’s due in June, at the same time as the National Academy study of dilbit and pipeline corrosion.

“Everybody is waiting for the NAS study,” says Carl Weimer, executive director of the Bellingham-based Pipeline Safety Trust, a national watchdog group founded in the wake of a deadly gasoline pipeline explosion there in 1999. “But some even question the group that got appointed to do that — three or four are current or former industry members.” Thomas Menzies, the NAS panel’s staff director, confirms that two of its 12 members are indeed former pipeline operators, for a reason: “Operational experience is essential to fulfilling the charge.”

Federal regulators do seem to have a lot of catching up to do. So far they’re been tiptoeing around dilbit questions: The National Transportation Safety Board’s review of the Michigan spill scourges Enbridge for various safety, maintenance, and response shortcomings, recommends corrections — and does not consider dilbit as a factor in the debacle. “I met with PHMSA [Pipeline and Hazardous Materials Safety Administration] regulators,” recounts Weimer. “I thought they’d know all the answers to these [dilbit] questions. But they didn’t.”

There’s one worrisome question that no one other than veteran marine advocate Fred Felleman even seems to be asking: Will this surge of new tar-sand oil be lightered — transferred — onto larger tankers for the Pacific crossing, and what new spill hazards would such transfers present?

Under the federal Magnuson Act, no tankers larger than 125,000 tons deadweight can ply the straits east of Port Angeles. In the past, shippers would park supertankers there and lighter onto them. That practice is still perfectly legal but dormant.

When Felleman raises the prospect of it reviving, he gets blank stares. But the economics suggest it’s not so farfetched. The 120,000-ton Aframax-class tankers that currently take Burnaby’s oil are mainly used on routes involving tight turns and moderate transits, as in the Mediterranean. They’re fine for the run to California, where 90 percent of current shipments from Burnaby currently go. And Trans Mountain’s Davies says they’re a “viable” vehicle for reaching high-priced Asian markets. But they’re hardly the most cost-effective one, especially since the shallow passage at Burnaby means even Aframax tankers can’t fill up completely there.

Lightering at Port Angeles would present one more chance for something to go wrong, notes Felleman — perhaps disastrously, what with the high pressure needed to pump heavy crudes such as dilbit.

Whatever findings emerge, both sides in the bitumen battle are likely to keep fighting. The stakes are too high to quit. The pipeline and tanker issues are real, but to environmentalists they’re also surrogates for a much bigger threat: Atmospheric carbon dioxide levels and the outsized contribution that Canada’s vast, dirty, inefficient oilsand resources can make to them. The outspoken NASA atmospheric scientist and climate campaigner James Hansen has famously predicted that if the tar sands get exploited, it’s “game over” for arresting global warming.

Canada’s business and government establishments likewise see bitumen exports as a make-or-break business. As long as those exports remain landlocked, Canada remains a captive supplier to the United States. That’s what candidate Mitt Romney hinted at when he defined the “energy independence” he promised as relying on “North American” fuels. And it’s a diminishing economic prospect as more U.S. fuel resources also come on line. The domestic price for the benchmark U.S. crude West Texas Intermediate currently lags the international price for Brent crude by about 16 percent; the gap between Brent and Western Canadian Select crude is twice that. Lack of access to overseas oil markets costs Canada an estimated $13 billion a year.

Like Russia seeking a warmwater port, the Canadian energy industry is looking in several directions. President Obama is set to weigh in again on the Keystone XL Pipeline, which would pump Albertan oil to Louisiana and which his administration blocked last year. Northern Gateway looks ever more doubtful, not just because of Enbridge’s knack for making enemies but because it must cross unabrogated First Nations lands whose holders have already announced their opposition. Trans Mountain also has anxious First Nation neighbors, the Tsleil-Wauthuth on Burrard Inlet, who oppose its expansion. But they don’t control the corridor, though it terminates in their traditional homeland.

Some U.S. critics suggest that if Canada’s so eager to get its oil to sea, it should build a pipeline to its own Atlantic ports, where it currently imports foreign oil. But that’s a much longer, costlier transit, with many more local interests to placate or overcome.