The Transportation Safety Board says external corrosion led to a natural gas pipeline rupture that caused an explosion near a small northern Alberta community. Transportation Safety Board of Canada signage is pictured outside TSB offices in Ottawa on Monday, May 1, 2023. THE CANADIAN PRESS/Sean Kilpatrick

The Transportation Safety Board says external corrosion led to a natural gas pipeline rupture that caused an explosion near a small northwestern Alberta community.

In a statement on the results of its investigation into the April 2022 blast near Fox Creek, Alta., the agency says it found the corrosion had weakened the pipeline wall, leading to the rupture.

It says the escaped gas ignited, causing a fire that “self-extinguished” after the manual closing of valves upstream and downstream of the break.

No injuries or evacuations resulted from the explosion.

The board says the investigation found the cathodic protection system meant to prevent corrosion wasn’t working as intended, and the external coating of the pipeline had degraded over time, exposing its surface to the environment.

It says factors that quickened the corrosion included proximity to another pipeline with a different operator, the characteristics of the soil, the degraded coating and an incomplete electrical bond in the cathodic protection system.

The board says the effectiveness of such systems, which use electrical currents to transfer corrosion away from the surface, may be compromised if pipeline operators aren’t aware of similar infrastructure operated by others nearby, adding there is no centralized system for that information in Canada.

In the case of the rupture near Fox Creek, the Transportation Safety Board says the operator of the pipeline, NOVA Gas Transmission Ltd., replaced the damaged sections and took steps to permanently shut down the pipeline.

This report by The Canadian Press was first published Jan. 9, 2024.

News from © The Canadian Press, 2023. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • 0079 Ministry of Energy Business_incentive PO
    0079 Ministry of Energy Business_incentive PO
  • 0078 LHOS 2024
    0078 LHOS 2024
  • 0077 Caprice Resources Stand Up For Free Speech
    0077 Caprice Resources Stand Up For Free Speech
  • 0053 Kingston Midstream Westspur Alameda
    0053 Kingston Midstream Westspur Alameda
  • 0076 Latus only
    0076 Latus only
  • 0073 SaskWorks-Pipeline Online
    0073 SaskWorks-Pipeline Online
  • 0063 Turnbull Excavating hiring crusher
    0063 Turnbull Excavating hiring crusher
  • 0061 SIMSA 2024 For Sask Buy Sask
    0061 SIMSA 2024 For Sask Buy Sask
  • 0058 Royal Helium Steveville opens anonymous rocket
    0058 Royal Helium Steveville opens anonymous rocket
  • 0055 Smart Power Be Smart with your Power office
    0055 Smart Power Be Smart with your Power office
  • 0051 JML Hiring Pumpjack assembly
    0051 JML Hiring Pumpjack assembly
  • 0049 Scotsburn Dental soft guitar
    0049 Scotsburn Dental soft guitar
  • 0046 City of Estevan This is Estevan
    0046 City of Estevan This is Estevan
  • 0041 DEEP Since 2018 now we are going to build
    0041 DEEP Since 2018 now we are going to build
  • 0032 IWS Summer hiring rock trailer music
  • 0022 Grimes winter hiring
  • 0021 OSY Rentals S8 Promo
  • 0018 IWS Hiring Royal Summer
  • 0013 Panther Drilling PO ad 03 top drive rigs
  • 0011
  • 0006 JK Junior
  • 0002 gilliss casing services
    0002 gilliss casing services
  • 9002 Pipeline Online 30 sec EBEX
    9002 Pipeline Online 30 sec EBEX
  • 9001