A few years from now, when our best-known marine life — endangered Southern Resident Killer Whales, threatened Puget Sound chinook salmon, or the Fraser River sockeye that have always made up the bulk of the Puget Sound commercial harvest — swim north to the Queen Charlotte Islands and beyond, they may encounter some new swimming companions: 1000-foot-long tankers known as Very Large Crude Carriers.  Each ship would be carrying up to 2 million barrels of dilute bitumen from the Alberta tar sands to foreign refineries, probably in China.

Enbridge Northern Gateway Pipelines Ltd. wants to build twin 730-mile pipelines from Alberta to a new oil port at Kitimat, B.C. One pipeline would take some 30 million tons of dilute bitumen a year to the coast. The other would carry inland the condensate used to dilute the bitumen.

Up to 250 chartered foreign-flag tankers a year would haul the bitumen away. If a tanker were bound for Asia, it would negotiate Dixon Entrance, between B.C. and southeast Alaska. If it were instead bound for California and its refinery capacity, it might head south, reaching the open ocean through the Strait of Juan de Fuca. The recent "Northern Gateway Project TERMPOL Review Process Report" by three Canadian government ministries, the Canadian Coast Guard and the Pacific Pilotage Authority explains that "[o]f these 250 vessels, up to 60 would have a deadweight of 320,000 tonnes. While there are currently large commercial vessels operating to and from Kitimat Harbour, the oil tankers used for the Northern Gateway Project would be larger."

The Northern Gateway project "would introduce some of the world's largest supertankers in an area that has never seen oil," says Katie Terhune, energy campaign manager of the Living Oceans Society. "No other tanker routes in the world are nearly this challenging." The big ships — which require several miles to stop — would "have to make five nearly 90-degree turns, [and] the channel's narrow."

Enbridge spokesperson Todd Nogier says that the waters of the B.C. coast aren't that different from those of Scotland or Norway, where the offshore oil industry has been operating for years. All else being equal, the more large vessels share space along the rocky B.C. coast, the greater the risk of something bad happening there. But, Nogier says, although the Northern Gateway project would increase vessel traffic through those waters — where much smaller ships already haul condensate to Kitimat — the company would install radar and other navigational aids that would make the waters safer for everyone.

Many environmental groups on both sides of the border would like to see the whole Alberta tar sands enterprise shut down. Tar sands development is eating into the boreal forest. Processing the bitumen requires huge amounts of water and energy. Putting billions of barrels of new petroleum onto the market just renews our commitment to the fossil-fuel-based energy system that helps drive global climate change.

But critics also raise specific objections to the Northern Gateway proposal. A lot of environmental groups and First Nations communities point to the environmental risks of both pipelines and tankers.

Number one, of course is the risk of a spill from the pipeline, which will cross two major tributaries of the Fraser, or from one of the ships, which will pass through the ocean migration routes of salmon from all the major B.C. coastal rivers, as well as Puget Sound, and pass through Alaskan waters, too. (The 320,000-deadweight-ton tankers occupy the upper limit of Very Large Crude Carriers, although they're smaller than Ultra Large Crude Carriers. By comarison, the ill-fated Exxon Valdez occupied the bottom of the VLCC range at a tad over 200,000 deadweight tons and a capacity a tad less than 1.5 million barrels.)

Critics cite the 2010 spill of dilute bitumen from a 30-inch Enbridge pipeline into a tributary of Michigan's Kalamazoo River as a cautionary tale. That spill dumped 819,000 gallons — or roughly 20,000 barrels — into the water. The oil spread downstream and out into the floodplain. The bitumen quickly sank. Crews are still cleaning it up.

Researchers are still assessing the environmental impact but the bill has already reached $700 million. "Not many people in the pipeline industry would have thought that a 20,000-barrel spill would be costing $700 million," says policy analyst Nathan Lemphers of Canada's Pembina Institute. The bitumen is "heavier than water, so it sinks after several days," he says. It also has a considerable heavy metal content. He worries about what would happen if it spilled in the deep, often rough water off the B.C. coast. "Even if it were to be conventional oil," he says, "a lot of [clean-up] technologies only work on calm water."

The company doesn't explain the Kalamazoo River spill away. Indeed, pending the results of the current research, the company doesn't explain it at all. "We have done everything that we can to learn everything that we can" from the incident, Nogier says. "It is an incident that is very humbling to this company."

Even if there were to be no major oil spill in the Northwest, critics worry about the ways in which the sound of many large ships might affect killer whales and other cetaceans.

"Killer whales (Orcinus orca) use sound for echolocation, social communication, and passive listening," explains a report done for NOAA in 2008. "Ambient noise, including that from natural and anthropogenic sources, has the potential to interfere with the reception and use of these important biological sounds. Significant sources of anthropogenic sounds that contribute to ambient background noise in critical habitats of SRKWs [southern resident killer whales] include sonar, acoustic harassment devices, vessel traffic, and construction noise." The Living Oceans Society's Terhune says, "There's a worry that these whale populations might leave."

But not everyone is convinced that bringing hundreds of big tankers into coastal waters would cause major problems. Indeed, the TERMPOL report — issued Feb. 23 by, among others, Environment Canada and Fisheries and Oceans Canada — found that it would not. The report cited the company's plans to require any ballasted tanker to be accompanied by a close escort tug, any laden tanker in a channel to be accompanied by two tugs, and a "requirement for tankers to modify their speed to reduce harm to marine mammals." (Ships hit whales. Why don't the whales stay out of the way? No one knows. But "whale strikes" happen.)

This report hardly gives Enbridge a green light, but it may make a green light more likely. "Though the review was voluntary," wrote Nathan Vanderklippe in the Toronto Globe and Mail, "it bears the imprimatur of the federal government, which is likely to carry substantial heft with the three-person Joint Review Panel examining the project. From that perspective, it is an important vote of confidence for Enbridge, which has long argued that it can safely move oil across the B.C. coast."

Critics argue that in any case, the risks of the pipeline and tankers aren't worth the rewards. The "Northern Gateway pipeline is not worth the risk for the communities, rivers and Pacific coastline of British Columbia," said Nathan Lemphers in a press release accompanying a November report on "Pipeline and Tanker Trouble." Economically, "there's very little economic gain for British Columbians," Terhune argues. "B.C. is just the doormat."