TSB releases investigation report into 2021 natural gas pipeline rupture in Manitoba
Gatineau, Quebec, 16 March 2023 — Today, the Transportation Safety Board of Canada (TSB) released its investigation report (P21H0143) into a natural gas pipeline rupture that occurred near McAuley, Manitoba in 2021.
On 05 October 2021, the Minell Pipeline, a 6-inch natural gas pipeline operated by Manitoba Hydro, was struck by the blade of a farm tractor as it was scraping the ground in an agricultural field near McAuley, Manitoba. The pipeline ruptured and released approximately 84 000 m³ of natural gas. The released gas did not ignite and no evacuation was required. No one was injured.
The investigation found that the depth of ground cover over the pipeline at the occurrence location was insufficient to prevent the ground-scraping blade from contacting the pipeline. Over time, the removal of weeds and silt from the drainage ditch gradually reduced the depth of cover over the pipeline. This was not identified by Manitoba Hydro’s damage prevention program, and, as a result, the pipeline kept operating with reduced ground cover.
The investigation analyzed the response time from when the rupture took place until the ruptured section of the pipeline was isolated. The rupture occurred near TC Energy’s Moosomin compressor station, which supplies the Minell pipeline. However, Manitoba Hydro’s procedures at the time of the occurrence did not identify TC Energy as a possible resource in the response to an occurrence, and the flow of gas continued into the ruptured section of pipeline until Manitoba Hydro was able to isolate it, 106 minutes after the rupture was suspected.
Following the occurrence, the TSB issued Pipeline Safety Advisory Letter 01/22 to Manitoba Hydro and indicated that pipeline operators need to be aware of the depth of cover over their pipelines to ensure they are adequately protected against normal agricultural activities that do not require explicit authorization. Manitoba Hydro completed a depth of cover survey for its entire Minell Pipeline, in response to an order issued by the Canada Energy Regulator with respect to the occurrence. Ten locations were found to have cover less than 0.65m, and these were staked and/or barricaded. The company also met with the affected landowners and provided written notifications in November 2021 prohibiting agricultural work, vehicle crossings and other ground disturbance activities in these locations.
See the investigation page for more information.
The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.
For more information, contact:
Transportation Safety Board of Canada