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BC Hydro Completes Investigation into Vault Fire, Taking Immediate Action

June 27, 2023
Leaking gasket and delayed equipment replacement contributed to fire and explosion, prompting BC Hydro’s immediate safety measures.

BC Hydro has concluded its investigation into the fire and explosion that took place in an underground electrical vault on Burrard Street in Vancouver in February. The investigation determined that the fire and explosion were caused by a buildup of flammable gases resulting from a leaking gasket in the lid of an oil-filled switch. The leak occurred because incompatible materials were used during the repair and maintenance of the gasket over time.

Furthermore, the investigation revealed that BC Hydro had previously identified significant risks associated with the vault. In 2016, BC Hydro assessed underground street vaults and classified 14 of them, including the one on Burrard Street, as high-risk in the event of a failure. The assessment warned that inadequate maintenance or replacement of the vaults could result in severe injury or death. It recommended replacing the equipment in the Burrard Street vault by 2018.

However, BC Hydro did not replace the equipment in the Burrard Street vault until after the fire and explosion occurred. This decision was made because the vault was excluded from the immediate project scope in favor of replacing the equipment in another vault in Gastown. It was expected that the Burrard Street vault would undergo maintenance, but the crews faced difficulties due to a lack of proper information, instructions, and the correct materials needed to complete the work.

In response to this incident and the findings of the investigation, BC Hydro is taking several immediate actions:

  • Decommissioning underground vaults with oil-filled equipment that were identified as risks in 2016, ensuring they no longer pose a threat.
  • Conducting a program review of other distribution street vault equipment, involving an independent third-party expert. The first phase of the review will be completed by the end of summer, and the second phase by March 2024
  • Engaging fully and transparently with regulators such as WorkSafeBC and the British Columbia Utilities Commission, and sharing the lessons learned with other utilities.

BC Hydro has invested approximately $195 million over the past decade to enhance the downtown Vancouver electrical infrastructure. These investments have included the installation of new feeders, voltage conversions, and the replacement of aging equipment.

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