A wildfire in west-central Alberta that was sparked by a gas pipeline rupture is under control, but an investigation into what caused the pipeline to break could take months or even years.

As of Wednesday morning, there was very little fire activity left in Yellowhead County, where a 10-hectare fire burned on Tuesday about 40 kilometres northwest of Edson, The Canadian Press reports. Edson is about 200 kilometres west of Edmonton and about 160 kilometres northeast of the British Columbia-Alberta border.

“For it to be considered extinguished, we’re going to have to hot spot,” said Caroline Charbonneau, area information coordinator with Alberta Forestry and Parks.

“That means we’ll have to dig into the ground, look and feel for hot spots, and then douse it with water. And that could take several days.”

The fire on Tuesday, which occurred as much of Alberta is dealing with extremely dry early spring conditions, was sparked when the pipeline owned by Calgary-based TC Energy Corporation ruptured. With 50 wildfires already burning across the province, the majority of them under control, CBC says Alberta is bracing for a long wildfire season fuelled by a persistent drought that already has a water regulator restricting water access for oil and gas fracking operations.

There were no injuries in the TC Energy rupture, and the fire was never a threat to any surrounding communities, CP writes. The affected pipeline segment was isolated and shut in and there is no more gas leaking from the pipeline.

The Canada Energy Regulator (CER) had inspectors onsite Wednesday to monitor the company’s response and the federal Transportation Safety Board is investigating the incident.

According to the CER, there have been 12 natural gas pipeline ruptures in Canada since 2008, and Tuesday’s incident near Edson was the first on that particular pipeline within that time period.

The 36-inch diameter pipe that ruptured is part of TC Energy’s Nova Gas Transmission Line (NGTL) pipeline system, which transports natural gas from Alberta and northeastern B.C. to domestic and export markets. The system spans 24,631 kilometres and connects with TC Energy’s Canadian Mainline system, Foothills system, and other third-party pipelines.

The NGTL pipeline system is like a web made up of different lines that have been developed in stages.

In 2022, there was a rupture on a separate part of the system that resulted in an explosion and fire near Fox Creek, Alberta. There were no injuries.

A TSB investigation into that incident took more than 14 months, and concluded that the pipeline ruptured due to reduced pipe wall strength caused by external corrosion.

While the primary risk of a crude oil pipeline leak is an oil spill that harms the local ecosystem, natural gas pipeline ruptures can and do result in fires or explosions, said Bill Caram, executive director of the Pipeline Safety Trust, a U.S.-based non-profit.

In 2017, an interactive map published by Greenpeace USA identified TC Energy’s predecessor, TransCanada Pipeline, as one of three companies that that had averaged one oil pipeline spill per week since 2010, based on data from the U.S. Pipeline and Hazardous Materials Safety Administration. But Caram told CP that gas pipelines are generally safe.

“The chances are extremely high that a molecule of natural gas that enters a pipeline will go through that pipeline without a failure. Pipelines are quite safe, and when you look at incident rates compared to other modes of transportation like rail or truck, they are much less likely to have a failure,” he said.

“But what you don’t get a sense of by looking at the risks of pipelines in that way is how catastrophic a failure can be when it does happen.”

According to the TSB, there were 19 recorded incidences of fires related to pipelines in Canada between 2012 and 2022.

The TSB’s most recent report on pipeline transportation safety in Canada states that in 2022 there were 100 companies transporting oil, gas, or both in the federally-regulated pipeline system, which includes approximately 19,950 kilometres of oil pipelines and approximately 48,700 kilometres of gas pipelines.

That year, there were 67 pipeline transportation accidents and incidents on federally regulated pipeline systems, the report said.

That number was well below the 10-year average of 112 occurrences, and was also the lowest count since 2019, when the TSB recorded 52 pipeline accidents or incidents.

The TSB defines a pipeline “accident” as an incident that results in a person being injured or killed, a fire or explosion, or significant damage to the pipeline affecting its operation.

Less severe pipeline events that involve the uncontrolled release of a commodity or a precautionary or emergency shutdown are classified by the TSB as “incidents.”

There have been no fatal accidents directly resulting from the operation of a federally-regulated pipeline system since the inception of the TSB in 1990.

This report by The Canadian Press was first published April 17, 2024.