Compliance Verification Activity Report: CV2223-307 - Trans Mountain Pipeline ULC


Compliance verification activity type: Field Inspection

Activity #: CV2223-307
Start date: 2023-02-01
End date: 2023-02-02


Regulated company: Trans Mountain Pipeline ULC

Operating company: Trans Mountain Pipeline ULC

Province(s) / Territory(s):


Related events:

Rationale and scope:

Inspection of INC2023-020 Railway Creek incident site. On 31 January 2023 the CER was notified that subsidence related to the trenchless crossing of Railway Creek (BC-646) for the Trans Mountain Expansion Project, spread 5B, KP 1030.79, caused temporary flow disruption to the creek. A portion of the bed and south bank of Railway Creek subsided and stream flow went subsurface. A temporary flume was installed to re-instate flow and remains in place. This inspection will look at effects to Railway Creek and potential effects to the Coquihalla River, located approximately 100 m downstream of the crossing.

Compliance tool(s) used:

Facility details


Regulatory requirements

Regulatory requirements that apply to this activity:

Regulatory instrument number(s):

Observations (no outstanding follow-up required)

Observation 1 - Railway Creek BC-646

Date & time of visit: 2023-02-02 10:00

Discipline: Environmental Protection




On 28 January 2023, during the execution of the trenchless (auger bore) crossing of Railway Creek (BC-646 Class S2-Fish Bearing), a portion of the bed and the south bank of Railway Creek subsided. The stream flow went subsurface at the point of subsidence. A temporary flume was installed to re-instate flow. CER Inspection Officers observed the site on 2 Feb 2023 and observed the Site Specific Contractor Execution Plan for Railway Creek.
During the inspection Trans Mountain representatives stated:

CER Inspection Officers requested the following documents:

Compliance tool used: No compliance tool used

Observations (company follow-up required)

Identified non-compliances to company plans or procedures are non-compliances either to:

- the condition of an authorization document that requires the implementation of that plan or procedure; or

- the relevant section of the regulations that requires implementation of that plan or procedure including those sections that require implementation of plans or procedures as a part of a Program