While observing that the "risk of large spills is generally low in Canada," the 256-page study finds that small spills "can also cause significant damage and are likely to happen much more frequently than larger spills."
Getting Canadian crude oil to tidewater for export has been a major preoccupation of the Conservative government in Ottawa, and the findings will add to the debate over several pipeline proposals — including two in B.C. that the report says will substantially increase marine risks.
The study, delivered this month to Transport Canada, looks at the risks associated with marine oil spills south of the 60th parallel under current shipping volumes.
It identifies the southern tip of Vancouver Island, the Cabot Strait off Newfoundland, the eastern coast of Cape Breton Island and the Gulf of St. Lawrence as the most probable areas for a major oil spill.
"These results demonstrate the need for Canada to tailor its preparedness efforts for each sector of the country, as the risks across the country are demonstrably different," says the study by WSP Canada Inc.
On Thursday, Natural Resources Minister Joe Oliver will introduce legislation dealing with offshore energy safety in an effort to get ahead of environmental concerns over Canada's oil boom. He's also expected to dramatically beef up nuclear industry liabilities.
The study for Transport Canada offers a mixed review for future risks.
It's not a picture likely to mollify concerns in B.C.
The report assessed the potential impact of four proposed pipeline projects, including the Northern Gateway pipeline to Kitimat and Kinder Morgan's plan to almost triple its Trans Mountain line into Vancouver.
The report says the Kinder Morgan proposal "would essentially double the volume of oil passing through" an already vulnerable marine environment, the area south of Vancouver Island where Washington-bound oil tankers are common.
"Doubling the volume of oil passing through Pacific sub-sector 5 would likely increase the spill risks to 'very high' for all zones (nearshore, intermediate and deep sea) for 10,000 square meter spill volume and greater," says the report.
The Northern Gateway marine route through the Douglas Channel out of Kitimat, meanwhile, would "raise the near-shore risk from 'very low' to 'very high' as observed in the Vancouver region (sub-sector 5)," states the report.
And risks for the largest spills in the deep sea sectors off the B.C. coast would rise from low to medium "due to the increase in traffic of very large volumes from sub-sector 2 to Asia or California."
All pipeline proposals do not raise the risk of marine spills, however.
The study found that reversing Enbridge's Line 9 to carry Western Canadian crude to refineries in Montreal and Quebec City would actually lower marine spill risks, as it would reduce oil imports through the sensitive Gulf of St. Lawrence.
And the study found that the proposed Energy East Pipeline to St. John, N.B., would likely be a wash, reducing shipping imports but increasing oil exports to leave the overall marine risk about where it is now.
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