Line 5 inspections

Regular examinations of the pipe, both inside and out.

Prevention is a key component of safety at Enbridge. Our proactive inspection program allows us to monitor the fitness of our pipelines from both the inside and the outside.

We take extra precautions on the Line 5 Straits of Mackinac crossing, with regular inspections that make this crossing the most inspected segment of pipe in our entire North American network. These measures include:

  • Thoroughly evaluating the pipe’s interior every five years, using our in-line inspection tools. These tools provide a level of detail similar to MRIs in the medical industry, allow us to examine the interior walls of our pipes inch by inch, and alert us to features that may require a closer look (click here to learn more about the results of our in-line inspections);

  • Regular visual inspections of the exterior of the pipe, using expert divers and/or remote operated vehicle (ROV), every two years (twice as often as federal regulations require). These external inspections provide a thorough, detailed look at the exterior of the pipe and its immediate environment (click here to find out more about our span management program);

  • In 2014, we retained GEI Consultants Inc., an independent firm founded by Harvard and MIT geotechnical engineers, to assess the mussels found along our Line 5 Straits crossing. GEI examined several factors, including mussel weight and mussel secretions, and determined that mussels accumulated on Line 5 in the Straits of Mackinac have no impact on the pipeline (click here to read the mussel study).

  • In 2016, we filed our Line 5 Biota Investigation Work Plan with the U.S. Environmental Protection Agency, Department of Justice and the Coast Guard, detailing our plan to ensure ongoing pipeline integrity as related to the Straits of Mackinac sections of Line 5.

    The draft plan proposes to look at how aquatic organisms in the Great Lakes may or may not be impacting the twin pipelines that comprise Line 5 as it crosses the Straits of Mackinac. It’s important to note that this is still a draft plan and is still under revision; the plan has not been approved by the U.S. EPA and the proposed tests have not yet occurred.

    We continue to work closely with the EPA, DOJ and the Coast Guard to finalize the plan.


Line 5 Operational Reliability Report

The safety and operational reliability of our pipelines is the very foundation for our business and is recognized as critical to assuring the Company’s ongoing success.

Safeguarding the Great Lakes

We take special precautions to protect the Great Lakes.