Investigation report on the 2024 NOVA Gas Transmission Ltd. Grande Prairie Mainline pipeline rupture is now live

October 9, 2025

The Transportation Safety Board of Canada (TSB) has released its final investigation report on the 2024 NOVA Gas Transmission Ltd. (NGTL) Grande Prairie Mainline pipeline rupture. On April 16, 2024, the 36-inch natural gas pipeline ruptured near Edson, AB, causing a small fire on Crown land. The TSB has found that the cause of the pipeline rupture was axially oriented Near-Neutral pH Stress Corrosion Cracking.

CER-regulated companies are required to follow the requirements outlined in the CER’s Onshore Pipeline Regulations and associated technical standards such as CSA Z662. This includes having an Integrity Management Program to identify hazards and mitigate risks related to pipeline integrity.

The CER will share learnings from the NGTL Grande Prairie Mainline pipeline rupture with its regulated companies to help prevent a similar incident.
Associated links

• News release: Canada Energy Regulator responds to pipeline rupture on NOVA Gas Transmission Ltd. Grande Prairie Mainline.
• Pipeline Profiles: NGTL