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Oil pipeline rupture by quake remains a worry

No known active faults but Kinder Morgan to fund more study of seismic risk near Trans Mountain terminal
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The collapse of the north face of Burnaby Mountain thousands of years ago may have been triggered by seismic movement along a suspected underlying fault.

Kinder Morgan is expected to carry out more research on the potential seismic risk of a quake rupturing its Trans Mountain pipeline and spilling oil into Burrard Inlet.

Belcarra Mayor Ralph Drew says a just-completed review of area geologic faults funded by Kinder Morgan is a good start but more work is needed to answer outstanding questions about the danger.

Some geologists in the past have suggested a fault triggered the historic slump of the north face of Burnaby Mountain an estimated 15,000 years ago.

Drew's nightmare scenario is for some similarly violent seismic event to strike today near the pipeline Kinder Morgan intends to twin and close to the Westridge Marine Terminal, where large amounts of oil is stored in tanks on a hill above the inlet.

"It doesn't take much land movement to result in a fracture to a hard object like a metal pipe," Drew said.

Geotechnical consulting firm BGC Engineering reviewed older research and concluded there are no known active faults in the Lower Mainland.

But BGC's report stresses that doesn't mean they don't exist – active faults might merely be undiscovered.

The U.S. has done more to search for seismic trouble spots and surveys there in recent years have revealed active faults within five kilometres of the border.

"It is possible that given comparable research, active faults could be found north of the border," the report says.

Studies in the 1970s and 1980s flagged several possible faults across Burnaby Mountain as well as around downtown Vancouver and Coal Harbour.

One also suggested an earthquake in 1859 may have turned Stanley Park, previously described as an island, into a peninsula.

BGC found insufficient evidence to determine if the possible faults around Burnaby Mountain are real or active, but it said modern imaging techniques and other geotechnical methods could shed more light.

Kinder Morgan is expected to finance more work as part of its proposed Trans Mountain pipeline twinning project, which would nearly triple pipeline capacity to 890,000 barrels per day.

Drew said the findings are important to determine if additional spill safeguards are needed in the area close to Burrard Inlet, including additional automated pipeline shutoff valves that reduce the amount of oil lost in a breach.

He said he finds it "a little bit odd" that in the 60 years the pipeline has operated its owners apparently never investigated potential geologic faults near the terminal that might put it at risk.

The BGC work was conducted after Drew and others first raised questions about seismic risks last fall, in response to the twinning plans.

"The good news is they're now on the case and investigating," Drew said.

Kinder Morgan officials said they do take seismic risks into consideration on an ongoing basis and the proposed pipeline twinning will include a thorough geotechnical assessment.

Spokesperson Lisa Clement said additional seismic studies by Kinder Morgan are ongoing and will be filed as part of the Trans Mountain expansion application to the National Energy Board, while additional investigation of risks around Burnaby Mountain will be done during the detailed design phase.

She noted in the 1990s a Lower Mainland geotechnical study prompted the drilling of a new crossing under the Fraser River between Surrey and Coquitlam to protect the pipeline from damage during an earthquake.

Drew is also pushing Kinder Morgan to conduct detailed baseline studies of the aquatic life and habitat found in Burrard Inlet that could be at risk in a spill – a request that has been endorsed by other local councils and Metro Vancouver.

Kinder Morgan oil storage tanks near Westridge Marine Terminal in north Burnaby.