Trans-Northern Pipelines Inc. Application dated 17 July 2025 to vary Order AO-001-SO-T217-03-2010 to remove the NPS 10 Toronto Airport Lateral from Schedule B and change the approved maximum operating pressure

Trans-Northern Pipelines Inc. Application dated 17 July 2025 to vary Order AO-001-SO-T217-03-2010 to remove the NPS 10 Toronto Airport Lateral from Schedule B and change the approved maximum operating pressure [PDF 199 KB]

File 4668651
21 November 2025

Lee Nanos
Trans-Northern Pipelines Inc.
310 – 45 Vogell Road
Richmond Hill, ON L4B 3P6

Dear Lee Nanos:

On 17 July 2025, the Canada Energy Regulator (CER) received an application from Trans-Northern Pipelines Inc. (TNPI) pursuant to section 69 of the Canadian Energy Regulator Act (CER Act), requesting that the Commission of the CER:

• vary Order OPLO-2-16-71 to change the maximum operating pressure (MOP) of the NPS 10 Toronto Airport Lateral (Line B10)^{Footnote 1} from 8 894 kPa to 4 275 kPa;
• vary Order AO-001-SO-T217-03-2010 to remove Line B10 effective 29 September 2025; and
• grant such further and other relief as TNPI may request and the Commission may consider appropriate.

On 27 August 2025 and 3 September 2025, TNPI submitted responses to CER requests for additional information about the application.

The Commission denies TNPI’s application but grants TNPI relief from filing the yearly engineering assessment for Line B10 required by Condition 2.c of Order AO-001-SO-T217-03-2010 for the 2025 calendar year. The Commission has also decided to temporarily vary Schedule B of Order AO-001-SO-T217-03-2010, pursuant to subsection 69(1) and paragraph 67(1)(b) of the CER Act, to change the reduced MOP at which TNPI can operate Line B10, from 6 226 kPa to 2 413 kPa.

Test for applications to review and vary previous decisions or orders

Subsection 69(1) of the CER Act provides that the Commission may review, vary, or rescind any decision or order it makes. Section 44 of the National Energy Board Rules of Practice and Procedure, 1995 sets out the required content of an application for this type of relief.

There is no automatic right of review. Rather, the Commission has a discretionary power to review its decisions, which it must exercise sparingly and with caution.^{Footnote 2}

The Commission considers applications for review through a two-step process.^{Footnote 3} In step 1, the Commission considers whether the applicant has raised a doubt as to the correctness of the decision. The Commission will consider any ground that raises a doubt, including an error of law or of jurisdiction, changed circumstances or new facts that have arisen since the close of the original proceeding, or facts that were not placed in evidence in the original proceeding and that were then not discoverable by reasonable diligence. A review application must also include the nature of the prejudice or damage that has resulted or will result from the decision or order. If the Commission finds that the applicant has met step 1, then it will proceed to step 2 and determine whether the decision should be confirmed, amended, or overturned.

Application to vary Order OPLO–2–16–71 to change the approved MOP for Line B10 to 4 275 kPa

The Commission denies TNPI’s request to vary Order OPLO–2–16–71 to change the approved MOP from 8 894 kPa to 4 275 kPa because TNPI did not demonstrate that it is safe to operate Line B10 at an MOP of 4 275 kPa.

TNPI met step 1 of the test for a review and variance. TNPI submitted in its application that the throughput requirements of Line B10 have changed since Order OPLO–2–16–71 was issued and, as a result, TNPI will operate Line B10 at or below 4 275 kPa. The Commission finds that this change in operating pressure requirement is a change of circumstances.

TNPI did not meet step 2 of the test for a review and variance because TNPI did not demonstrate that it is safe to operate Line B10 at an MOP of 4 275 kPa. TNPI stated in the application that its 2024 annual engineering assessment of Line B10, which TNPI relied on to demonstrate that Line B10 is fit for service at 4 275 kPa, did not identify any crack anomalies as actionable. The Commission notes, however, that TNPI’s assessment does not comply with clause 10.10.1.1 of CSA Z662 Oil and Gas Pipeline Systems. Clause 10.10.1.1 requires, as part of an assessment of the acceptability of imperfections detected using in-line inspection, consideration of the growth rate of imperfections compared to the reassessment interval and tool uncertainties. TNPI’s 2024 annual engineering assessment estimated crack failure pressures based on the dimensions determined by the crack in-line inspection conducted six years earlier, in 2018. On 27 August 2025, in response to a request to recalculate the present-day failure pressures for six unrepaired crack imperfections, TNPI confirmed that the six cracks have not been addressed and that some presently have estimated failure pressures approaching the requested MOP of 4 275 kPa.

TNPI subsequently submitted, on 3 September 2025, that it is currently operating Line B10 under a capped pressure of 2 413 kPa, and it will continue to do so at least until it completes in-line inspections scheduled for Q4 2025, and pending assessment of the results.

Based on TNPI’s submissions, the Commission finds that TNPI did not demonstrate that Line B10 is safe to operate at an MOP of 4 275 kPa. As a result, the Commission denies TNPI’s request to vary Order OPLO–2–16–71 to change the approved MOP from 8 894 kPa to 4 275 kPa.

Application to vary Order AO–001–SO–T217–03–2010 to remove Line B10 from Schedule B effective 29 September 2025

The Commission denies TNPI’s request to remove Line B10 from Schedule B of Order AO–001–SO–T217–03–2010. TNPI submitted in its application that the throughput requirements of Line B10 have changed since Order OPLO–2–16–71 was issued and, as a result, TNPI will operate Line B10 at or below 4 275 kPa. However, the Commission denied TNPI’s request to change the approved MOP for Line B10 from 8 894 kPa to 4 275 kPa on the basis that TNPI did not demonstrate that it is safe to operate Line B10 at an MOP of 4 275 kPa. As a result, the approved MOP for Line B10 has not changed as requested, and TNPI did not meet step 1 of the test for the Commission to review and vary Order AO–001–SO–T217–03–2010.

Commission decision to temporarily vary Order AO–001–SO–T217–03–2010 to reduce the MOP of Line B10

The Commission has decided to temporarily vary Order AO–001–SO–T217–03–2010 to change the reduced MOP at which TNPI can operate Line B10, to 2 413 kPa. Order AO–001–SO–T217–03–2010 restricts the MOP at which TNPI can operate Line B10 to 70 per cent of its authorized MOP. The authorized MOP for Line B10 is 8 894 kPa, such that the reduced MOP at which TNPI can currently operate it is 6 226 kPa.

The Commission found, above, that TNPI failed to demonstrate that it is safe to operate Line B10 at an MOP of 4 275 kPa, which is lower than the reduced MOP of 6 226 kPa at which TNPI is currently authorized to operate Line B10. As a result, the Commission finds that it is necessary to reduce the MOP at which TNPI can operate Line B10 to below 4 275 kPa, until TNPI files an engineering assessment that demonstrates that Line B10 is safe to operate at a different MOP. As noted earlier in this decision letter, TNPI submitted that it is currently operating Line B10 under a capped pressure of 2 413 kPa, and it will continue to do so at least until it completes in-line inspections scheduled for Q4 2025, and pending assessment of the results. The Commission finds that TNPI demonstrated in its submissions that it is safe to continue to operate Line B10 at an MOP of 2 413 kPa.

Accordingly, the Commission is temporarily varying Order AO-001-SO-T217-03-2010, pursuant to subsection 69(1) and paragraph 67(1)(b) of the CER Act, to change the reduced MOP at which TNPI can operate Line B10 from 6 226 kPa to 2 413 kPa, until TNPI files an engineering assessment in accordance with CSA Z662 Clause 10.1 Engineering assessments of existing pipelines. The engineering assessment should integrate the latest in-line inspection information for Line B10 and demonstrate either that it is safe to continue to operate Line B10 at an MOP of 2 413 kPa or that it is safe to operate it at a different MOP.

Commission decision to grant temporary relief from Condition 2.c of
Order AO–001–SO–T217–03–2010 for Line B10

The Commission found above that TNPI demonstrated that it is safe to operate Line B10 at a maximum pressure of 2 413 kPa. TNPI submitted that it plans to collect further information on the integrity status of Line B10 through in-line inspections scheduled for Q4 2025, and to analyze the results. The Commission therefore grants TNPI relief from the requirement to file an annual engineering assessment for Line B10, under Condition 2.c of Order AO–001–SO–T217–03–2010, for the 2025 calendar year. TNPI will be required to resume its annual filing of engineering assessments for Line B10 under Condition 2.c of Order AO–001–SO–T217–03–2010 in 2026.

Yours sincerely,

Ramona Sladic
Secretary of the Commission

c.c. Jane Keast, TNPI
Gail Sharko, TNPI

Date modified:

2026-02-10