Enbridge analyzes spill potential into Stuart Lake

Enbridge responds to information requested during the Joint Review process on potential impacts on sensitive areas.

A response provided by Enbridge for the potential for oil to end up in Stuart Lake did not satisfy a local man.

An inquiry into how a pipeline rupture could impact Pitka Creek and the downstream Stuart Lake came up short for Kelly Izzard, when the map indicating the potential spill area cut off right at the boundary of Stuart Lake, leaving the large lake out of the equation.

“It was patently obvious that the map they provided the [Joint Review Panel] cut off the result at the boundary of the map,” said Izzard.

Enbridge initially said their modelling did not show a spill near Pitka Creek reaching the lake.

So Izzard insisted they revisit their analysis when the company came to the community for a public meeting in December of 2011.

Recently, after another email from Izzard, the company responded, saying they did revisit their analysis for modelling the possibility for a break in the pipeline in the vicinity of Pitka Creek.

In their subsequent analysis, bitumen from the pipeline could end up in Stuart Lake in the case of the complete rupture of the pipeline, depending on flow rate and time of year.

But the analysis will change again, according to Paul Stanway, spokesperson for Enbridge. “This is a work in progress,” said Stanway. He said the maps for the Pitka Creek area will continue to change over time and the company will be integrating mitigating measures into their design.

Some specific measures would not be determined until after the project received approval, however, as the more exact engineering does not get done until then.

“When you get down to the detailed engineering … it gets very expensive,” said Stanway.

The analysis to create the latest map used annual mean flow rates and a complex physics formula taking into consideration stream flow rate and the flow rate of the bitumen from the pipe while also factoring in an estimate of how long it would take a control room operator in Edmonton, where the pipeline would be monitored from, to detect the rupture and shut down the pipeline.

Their original response to Izzard indicated the company did not expect a rupture above Pitka Creek to enter into Stuart Lake, but their second response indicated they had improved some of their modelling of a potential spill and the company had increased the possible response time for a control room operator in Edmonton to detect the leak and shut down the line from five minutes to 13 minutes.

“The reality is that in the event of a full-bore rupture, we expect the control centre operator to very quickly receive data from a number of sensors along the pipeline and respond very quickly to isolate the pipeline,” said Ray Doering, Enbridge engineering manager for Northern Gateway, in his response to Izzard. “We have taken a very conservative approach by using a 13 minute isolation time in this latest spill trajectory modelling and mapping.”

The company did experience a much longer response time after a break in a pipeline in Kalamazoo, Michigan, which spilled into the Kalamazoo River. But Stanway points out the pipeline there was much older and he said improvements have been made concerning control rooms in Edmonton, where personnel are supposed to be picking up those leaks and ruptures.

“The reality is that would not happen,” said Stanway. He said the company has learned a lot since the Kalamazoo, Michigan spill, and typically a pipeline built now would have a lot more shutoff valves.

While the response shows to Izzard Enbridge is working to identify potential impacts on areas of consequence along the pipeline route, he said he does still have some reservations about how the engineers are modelling the risk using an annualized approach to the flow of the creek to calculate the potential impact.

“When they develop their protocols and strategies for addressing a potential spill in Pitka Creek, it has to be focussed on when the hazard is greatest and that is during peak flow and then their response times have to be commensurate with that,” said Izzard. “If they can’t do it then they have to come up with some other mitigating approach, something which reduces the likelihood of a spill ever occurring.”

Izzard was interested in the impacts on Stuart Lake because he said wants people in the area to be aware of the risks of the proposed development so they can make informed decisions about whether or not they see the risks outweighing the benefits or vice versa.

“Ultimately, what I want to see is, a debate about the project,’ said Izzard. “It’s merits, its risks, at all levels, whether it be globally, federally, provincially and in some cases, most importantly, locally – in these areas of consequence where people’s lives potentially are effected directly.”

Public concerns over pipelines increased last week when a Pace Oil and Gas pipeline in northern Alberta ruptured and a spill of oil and water estimated at 22,000 barrels leaked onto the Alberta muskeg. The spill reportedly went undetected for days and was eventually discovered after another company’s airplane flew over the area and spotted it from the air.

Previous stories on Enbridge’s Northern Gateway Project proposal:

Enbridge talks to Chamber of Commerce in Fort St. James

Local group looking for answers takes on the daunting role of intervenors

Comments on Northern Gateway draw fire

Landowner group forms