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

Overview

Compliance verification activity type: Field Inspection

Team:

• Inspector 2850
• Inspector 2194

Regulated company: Trans Mountain Pipeline ULC

Operating company: Trans Mountain Pipeline ULC

Province(s) / Territory(s):

• British Columbia

Discipline(s):

• Environmental Protection
• Indigenous Monitoring

Related events:

• INC2023-020

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:

• None

Facility details

Facilities:

• TRANS MOUNTAIN EXPANSION PROJECT

Facility Types

• Pipeline
• Pipeline right of way (ROW)

Life-cycle Phases

• Construction

Regulatory requirements

Regulatory requirements that apply to this activity:

• Canadian Energy Regulator Act (CERA)
• Canadian Energy Regulator Act (CERA)
• Plans And Procedures
• Project-specific Environmental Protection Plan (EPP)
• Pipeline Environmental Protection Plan for the Trans Mountain Pipeline ULC Trans Mountain Expansion Project dated July 2022
• Standards
• CSA Z662-19 - Oil and Gas Pipeline Systems

Regulatory instrument number(s):

• OC-065

Observations (no outstanding follow-up required)

Observation 1 - Railway Creek BC-646

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

Discipline: Environmental Protection

Categories:

• Water Bodies - Fish-bearing
• Disturbance

Facility:

• TRANS MOUNTAIN EXPANSION PROJECT (Pipeline)

Observations:

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:

• The area was highly impacted during the 2021 flood event and at the time the creek was naturally diverted down the Enbridge pipeline right-of-way.  Ministry of Transportation and Infrastructure (MOTI) reclaimed and reconstructed the bed and banks of the creek. The creek is currently lined with geotextile and rip rap.
• Flow immediately went into the bore pit but soon after found a different subsurface path.  
  Water remained subsurface for approximately one hour while crews re-established flow through a flume. Screened pumps and a flume were on site when the event happened.
• From the crossing location the creek flows under Highway 5 and through a hanging culvert and enters the Coquihalla River approximately 100 meters downstream. The Resource Specialist on site stated it would be unlikely or difficult for fish to reach the crossing because of the height of the culvert and the gradient of the slope.
• A Trans Mountain Environmental Inspector was immediately on site and inspected the dewatered creek for evidence of fish being stranded or killed. No fish were observed from the sinkhole to the highway.  Railway Creek on the east side of the highway was not inspected.
• Turbidity levels were collected one hour after the flume was installed recording 0.08 NTU upstream of the sinkhole and 3.94 NTU downstream. After 2.5 hours turbidity levels were 0.34 NTU downstream. Turbidity levels were not collected at the Coquihalla River.
• The auger bore was 4 meters under the thalweg of the creek.
• Flow was directed through the flume using poly and sandbags.
• DFO, TSB, CER, and EMBC were notified of the event.
• A new Site Specific Contractor Execution and Restoration Plan would be developed and approved by Trans Mountain prior to any reclamation work being done on the crossing. The creek will be fully isolated for any instream activities.
• Current flow rates could be maintained by using one 6” pump but 3 additional 6” pumps with hoses will be onsite for back up.
• Trans Mountain will discuss the site with Ministry of Forests, Lands and Natural Resource Operations (FLNRORD) prior to instream work.
• There are two additional auger bore crossings remaining to be completed on spread 5B including Dewdney Creek (BC-632) and Ladner Creek (BC-629).

• Site Specific Reclamation Plan once developed.
• Geotechnical Assessment if available.
• Triton Assessment (Daily Field Report).
• Water Quality Monitoring results completed by EI post subsidence event.
• EI assessment summary (excerpt from daily report).
• Outcome of conversation with FLNRORD.  (Notification of planned in-stream emergency work to be provided to FLNRORD).
• Outcome of conversation with TMEP Engineering regarding why the subsidence occurred, and if a similar event is likely to occur during the Dewdney Creek and Ladner Creek trenchless crossing.

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: