The ability to detect leaks along the proposed Northern Gateway pipeline won't be known until the pipeline is built and pumping oil through the remote wilderness of northern B.C., a lawyer for the province noted at a hearing deciding the pipeline's fate.

Chris Jones grilled a panel of company experts on the design of the 1,100-kilometre pipeline that would deliver oil from the Alberta oilsands to a tanker port on the B.C. coast.

"So is what you're telling me that the actual sensitivity of a pipeline – perhaps this pipeline, along with other ones – can only be determined when it's actually been constructed and you're able to test that actual pipeline in operation?" Jones asked on the second day of environmental assessment hearings in Prince George, B.C.

'Whatever industrial activity you have, it has some element of risk.'—Enbridge Northern Gateway Pipelines president John Carruthers,

"We have a quite an operating history.... It's not an issue of ‘Trust us, wait 'til construction,’" answered Barry Callele, director of pipeline control systems and leak detection for Enbridge Pipelines Inc.

Testing is and has been under way, Callele said, and test results show the estimates provided in the project proposal are conservative.

5 detection systems

Callele said there would be five overlapping leak detection systems on the twin pipelines that would carry diluted bitumen to the tanker port in Kitimat, B.C., and condensate from Kitimat back to Bruderheim, Alta., including aerial surveillance, foot patrols, and 132 monitored pressure valves along the route.

"We will have one of the best instrumented pipeline systems not only in North America, but probably the world," Callele told the panel.

Jones pointed out that according to U.S. data, there were 31 leaks from Enbridge pipelines in that country since 2002, and six of the 10 largest spills by volume in that time were from Enbridge pipelines. Of those six, none were detected by Enbridge leak detection systems, Jones said.

B.C. Environment Minister Terry Lake issued a statement late Wednesday saying the government is "extremely concerned" about the answers heard at the hearings.

"The responses from Enbridge/Northern Gateway to cross-examination by our legal counsel are too often incomplete and lacking in commitment," Lake said. "Their answers suggest that the company is not taking the very real concerns of British Columbians seriously."

John Carruthers, president of Enbridge Northern Gateway Pipelines, said outside the hearings that people have concerns about whether the pipeline can be built and operated safely, and the questions being raised in the hearing room are "very legitimate."

'Some element of risk'

But Northern Gateway is a state-of-the-art system, he said.

"Whatever industrial activity you have, it has some element of risk," Carruthers told reporters.

"The real key is to try and get that as low as possible. In our case, we're trying to get that to zero. So that's the direction you're going and you try and do the best you can with processes, with people and with technology."

His sentiments were echoed 800 kilometres away at a conference on pipeline safety organized by the B.C. Chamber of Commerce in Vancouver.

Ziad Saad, a vice-president of the Canadian Energy Pipeline Association, said data collected from members shows there's been about three spills annually for the past decade.

That's better than a decade ago, he said, although zero is the goal.

"We don't pretend that we are here today at zero incidents and we don't pretend that we're going to be there next year," he said. "But that remains the goal. Period. We're always going to strive to have zero incidents of releases or leaks."

'Pinhole' leak detectable

Janet Holder, executive vice-president of western access for Enbridge, told the Vancouver meeting the technology to detect leaks has continued to evolve, especially over the last five years.

"There are new technologies we're testing actually as we speak that will find a tiny pinhole leak in a pipeline that could not possibly be found before," she said.

The conference also heard that tanker traffic off B.C.'s coast will increase dramatically if Northern Gateway and a proposed Kinder Morgan pipeline expansion go ahead.

The number of tankers plying the coast would rise from 100 at present to 550, said Jonathan Whitworth, CEO of Seaspan and representative of Canadian companies involved in coastal marine transportation, ship escorts and ship repair.

Whitworth said Seaspan has safely moved some 20,000 ships through the narrow passage under Vancouver's Lions Gate Bridge, a much more difficult trip than the one through the channel that would be used by the Northern Gateway's tankers.

"It’s a factor of about eight times wider than what we what we successfully do, well, about 20,000 times over," Whitworth said.

With files from the CBC's Chris Brown