Report into rupture of Manitoba Hydro pipeline released

The Transportation Safety Board has released its final report into the rupture of a natural gas pipeline owned by Manitoba Hydro in 2021.

According to the report, released Thursday morning, a section of the Minell Pipeline was hit by a farm tractor working in a field near McAuley, located roughly 141 kilometres northeast of Brandon, on Oct. 5.

A map shows the location of the pipeline rupture.

The tractor was scraping the ground when its blade hit the pipe. When the pipe ruptured, approximately 84,000 cubic metres of natural gas was released. No injuries were reported, no evacuations were required and the gas did not ignite.

“As a result of this occurrence, the pipeline was shut down for approximately three days,” the report reads. “The shutdown disrupted the supply of natural gas to the downstream distribution systems, extending to the town of Dauphin. Large commercial clients were asked to cut back operations to conserve the gas remaining in the pipeline. No residential customers lost gas service during the outage.”

A photo shows the path a tractor pulling a blade took before it struck a section of pipeline in McAuley, Man. on Oct. 5, 2021. (Image source: TSB)

The investigation from the TSB revealed that the depth of soil covering the pipeline was insufficient, and weed and silt removal from a drainage ditch had gradually reduced the ground cover over time.

“The depth of cover over the pipe where the blade made contact was determined to be less than 0.12 (metres),” the report reads.

The minimum depth of cover needed on the pipeline at the time was 0.60 metres. The TSB said the depth of cover near where the rupture happened was last measured in 2009 at 0.88 metres.

Manitoba Hydro, which operates the pipeline, completes surveys on the entire length every 15 years. In 2024, it would be transitioning to every 10 years.

“The activity of removing weeds and silt inherently removes some amount of soil, including some of the cover over the pipeline. However, Manitoba Hydro’s damage prevention program did not identify the removal of small amounts of cover over time as a hazard,” the TSB said.

As a response to the rupture, Canada’s Energy Regulator ordered Manitoba Hydro to survey the entire pipeline, where 10 locations with insufficient cover were found. Agriculture work, vehicle crossings and other ground disturbing activities were banned in those areas.

In a prepared statement, a Manitoba Hydro spokesperson said safety remains a top priority for the organization.

“Manitoba Hydro has already taken steps to complete a depth of cover survey for the entire Minell Pipeline and meet with affected landowners, as well as committed to taking the steps necessary to prevent such occurrences from happening in the future,” the statement reads.