ARCHIVED - Letter and Order AO-001-SO-E102-002-2011 to Enbridge Pipelines (NW) Inc.

Letter and Order AO-001-SO-E102-002-2011 to Enbridge Pipelines (NW) Inc. [PDF 72 KB]

File OF-Surv-Inc-2011 74 01
8 March 2013

Ms. Abby Dorval
Senior Manager, Regulatory Affairs
Enbridge Pipelines Inc.
30^th Floor
425 - 1^st Street S.W.
Calgary, AB  T2P 3L8
Facsimile 403-767-3863

Dear Ms. Dorval:

Enbridge Pipeline (NW) Inc. (Enbridge) filings dated 20 December 2012 pursuant to Paragraph 3 of NEB Order SO-E102-002-2011

Subsequent to the crude oil release that occurred on 9 May 2011, the National Energy Board (Board) issued Order SO-E102-002-2011 (Order) to Enbridge on 9 June 2011, imposing a pressure restriction on the Norman Wells to Zama Pipeline (Line 21).

Paragraph 3 of the Order directs Enbridge, in the event that it does not apply for leave to remove the pressure restriction on Line 21, to provide by 31 December 2012 an engineering assessment that indicates that the pipeline remains fit for its intended service at the reduced pressure.

On 20 December 2012, Enbridge submitted the engineering assessment pursuant to Paragraph 3 of the Order. The Board has reviewed the engineering assessment filed by Enbridge. The Board notes that Enbridge has implemented several measures in detecting and mitigating cracking features on Line 21 by conducting in-line inspections and selected excavation programs. The Board further notes that Enbridge has made progress in its investigation into the cause of the defect at KP 380.46 and expects Enbridge to submit an up to date engineering assessment when it completes its investigation.

The Board recognizes Enbridge’s efforts in demonstrating that Line 21 remains fit for its intended service at the reduced pressure. The Board further recognizes the voluntary additional pressure restriction for Mackenzie to Zama segment of Line 21. The Board is of the view that the additional pressure restriction should remain in place until such time as Enbridge has demonstrated that Line 21 is fit for service at the maximum operating pressure.

Accordingly, the Board has issued Amending Order AO-001-SO-E102-002-2011 which requires Enbridge to seek leave of the Board prior to lifting the additional pressure restriction on Line 21.

Yours truly,

Sheri Young
Secretary of the Board

Attachment

BEFORE the Board on 8 March 2013.

WHEREAS on 9 June 2011, the Board issued Order SO-E102-002-2011 (Order) to Enbridge Pipelines (NW) Inc. (Enbridge), pursuant to sections 12 and 48 of the Act, the effect of which was to impose a pressure restriction on the Norman Wells to Zama Pipeline (Line 21).

AND WHEREAS Enbridge operates Line 21;

AND WHEREAS Enbridge has filed an engineering assessment in compliance with Paragraph 3 of the Order;

AND WHEREAS the Board is of the view that Enbridge has implemented several measures in detecting and mitigating cracking features on Line 21;

AND WHEREAS Enbridge will continue to conduct weekly aerial patrols of Line 21 to monitor for leaks;

AND WHEREAS Enbridge has initiated and will continue to conduct quarterly high-resolution in-line leak detection inspections of Line 21;

AND WHEREAS Enbridge has initiated and will complete axial crack in-line inspections of Line 21 and has initiated and will complete the investigation into the cause of the defect;

AND WHEREAS the Board is of the view that interim precautionary measures are necessary for public safety and protection of the environment;

IT IS ORDERED THAT, pursuant to sections 12 and 48 of the NEB Act, the Board hereby amends Order SO-E102-002-2011 by replacing Paragraphs 1-3 with the following:

1. Enbridge will maintain the following pressure restrictions on Line 21
   

   Segment and temporary maximum operating pressure

   Segment	Temporary Maximum Operating Pressure (kPa)
   Norman Wells to Wrigley	7735
   Wrigley to Mackenzie Highway	5723
   Mackenzie Highway to Zama	4744

2. Enbridge shall, at least 30 days prior to increasing the operating pressure of any portion of Line 21 above the pressure restrictions set out in Paragraph 1 of this Amending Order, submit a written request to the Board seeking approval to lift the pressure restriction. The application shall include: an engineering assessment that indicates that the pipeline is fit for its intended service at the higher pressure. The engineering assessment shall include supporting rationale and documentation such as the results of any crack in-line inspection; the conclusions of Enbridge’s investigation into the cause of the defect at KP 380.46; and a plan to mitigate any other similar defects or anomalies on Line 21.
3. In the event that Enbridge does not apply for leave to remove the pressure restriction on Line 21, Enbridge shall, by 31 December 2013 provide an engineering assessment that indicates that the pipeline remains fit for its intended service at the reduced pressure taking into account factors such as the results of all crack in-line inspections performed on Line 21 to date, the conclusions of Enbridge’s investigation into the cause of the defect at KP 380.46 and a plan to mitigate any similar defects or anomalies on Line 21.

The Board further amends Order SO-E102-002-2011 by inserting the following as Paragraph 5:

5. Enbridge will report to the Board any release of crude oil of any volume on Line 21, in addition to the current reporting requirements to the Transportation Safety Board (TSB).

NATIONAL ENERGY BOARD

Sheri Young
Secretary of the Board

AO-001-SO-E102-002-2011

Date modified:

2020-09-29