How We Prevent Incidents

For Enbridge, our primary duty is to protect the safety of people and the environment while safely delivering the energy we all count on. That means anticipating and addressing potential problems to prevent incidents long before they occur. This approach guides every one of our decisions, actions and interactions as we plan and build new projects, and as we operate and maintain our systems, every day.

Case Study

Making a safe pipeline safer

For 65 years Enbridge’s Line 5, running from Superior, Wisconsin to Sarnia, Ontario, has safely supplied crude oil and natural gas liquids to the markets it serves.

When the pipeline was built in 1953, the 4.6-mile crossing on the lakebed beneath the Straits of Mackinac in water up to 220 feet deep was considered an engineering marvel. Since then Enbridge has carefully operated and maintained this vital energy link, protecting the safety of our neighbours and the environment while ensuring reliable delivery of the energy our society counts on.

In December 2018, Enbridge reached an agreement with the Mackinac Straits Corridor Authority to make this safe pipeline even safer, replacing our Line 5 Straits of Mackinac crossing with the pipeline secured in a larger tunnel, bored through rock deep beneath the lakebed.

Our 65-year track record of safety with the Straits of Mackinac crossing has been exemplary, driven by continuous monitoring, conservative operation and diligent maintenance, as well as regular inline inspections and external inspections by expert divers and remotely operated vehicles.

Further, in keeping with our existing commitment to safety, we have established enhanced inspection and operations protocols to ensure that the current Line 5 dual pipelines will continue to be operated safely while the tunnel is built.

Even so, we understood that routing Line 5 through a tunnel well below the Straits would add additional layers of safety. Built with a 1-foot-thick reinforced concrete liner and bored at a depth of as much as 100 feet beneath the lakebed, the tunnel reduces the chances of a leak into the Great Lakes to virtually zero and eliminates the possibility of accidental anchor strikes from shipping in the Straits. What’s more, the tunnel may provide access for Enbridge crews for ongoing inspection and maintenance of the pipeline.

“This major infrastructure project is an investment in Michigan,” says Brad Shamla, Enbridge’s Vice President of U.S. Liquids Pipelines operations. “It will deliver long-term environmental protection, as well as energy security, jobs and opportunities for the people of Michigan.”

“Line 5 is an important part of Michigan’s energy infrastructure,” Brad adds. “And placing a new tunnel under the Straits will eliminate potential risks—while ensuring a reliable and affordable energy supply to both the Upper and Lower Peninsulas.”

Find out more about our approach to ensure safety in the Straits.


Click on the image above to see animation video of the Line 5 tunnel project.


Adding Real-Time Radiography to the pipeline integrity tool box

Enbridge is pioneering a new approach to analysing and ensuring the quality of girth welds—where the ends to two pipes are welded together—with a digital update on X-ray technology.

Called real-time radiography (RTR), the novel tool is part of a wide group of techniques called non-destructive testing (NDT) that allow experts in a variety of industries—including aviation, automotive, construction, transportation and energy—to evaluate the condition and properties of a material without causing damage. Other types of NDT include ultrasound and magnetic flux leakage.

And while the preferred inspection method for welds on new pipeline projects is Automated Ultrasonic Testing, RTR is proving to be a useful complement, helping to prevent problems before they occur by providing Enbridge teams with another way to test and confirm the quality of pipeline girth welds.

“I look at NDT as a tool box,” says Axel Aulin, Enbridge’s senior NDT specialist. “In there, you’re going to have a crescent wrench. You’re going to have a hammer. You’re going to have a screwdriver. You can’t do the job with just a wrench or a hammer. You need different applications at different times.”

Starting with the Norlite pipeline project, which entered service in 2017, Enbridge has successfully tested and implemented the use of RTR to inspect field girth welds—a significant advancement from traditional film-based radiographic testing.

RTR is beneficial for inspecting welds with unique characteristics—including those that join pipe segments with different thicknesses, or temporary welds.

The technique is performed in one continuous scan, and offers fewer hazards for workers, a faster digital image with no associated film processing errors, extra film costs, film storage requirements, or film degradation.

There’s also the added benefit of immediate remote auditing—a vast improvement over film-based radiography.

“With RTR, the field crews can e-mail the weld image to our RT assessor or auditor, so it can be examined immediately,” says Aulin. “As a result, we’ve been able to reduce the amount of unnecessary rework due to non-compliant radiographic film images.”

“In Canada, we’re the first operator (in the Canadian Energy Pipelines Association) to implement RTR and address it in our specifications,” says Aulin.

“Automated Ultrasonic Testing has seen great progress, worldwide, but in my opinion there may always be a need for RTR.”

Creating a 'digital twin' of our pipeline systems to visualize and assess their health

Enbridge has a long history of driving innovation to prevent incidents and enhance our safety performance. From advanced inline inspection tools and cutting-edge monitoring and control systems to new technologies, we’re always looking for new ways to make our operations safer, protecting our neighbors, communities, employees and the environment from harm.

Over the last few years that effort has gone virtual, literally.

Enbridge partnered with Microsoft and Finger Food Studios to find a way to take the millions of individual data points—collected and reported by in-line inspection (ILI) toolsstrain gauge sensors, and other remote sensing systems that help us monitor the health of our pipelines—and translate them into an accurate and detailed digital 3D model.

“Enbridge is quite diligent about using overlapping inspection and prevention techniques to diagnose pipeline fitness. But the challenge lies in the fact that there is no way of quickly and effectively visualizing all of the data that’s collected,” notes Tony Khoo, manager of Enbridge’s advanced analytics team.

“Much of the information exists as Excel files, and becomes a struggle for our pipeline engineers to visualize multiple data sets—and understand the underlying data relationships to one another.”

Enter our partnership with Microsoft and Finger Food Studios, taking the vital first step towards creating a “digital twin” of Enbridge’s vast pipeline network. That meant taking 132 separate sets of pipeline data, as well as terrain information, to create a mixed reality environment depicting a 2.25-square-kilometer area in northern Alberta encompassing an Enbridge pipeline right-of-way.

This augmented/mixed reality setting provides a 3D rendering of pipeline sections—demonstrating the ability to process vast quantities of data and present the information in three dimensions. As a result, users can better pinpoint potential hazards in the pipe—including small dents, cracks, areas of corrosion, and pipeline strain caused by incremental ground movement.

Wearing Microsoft’s HoloLens glasses, users would be able to rotate, zoom and expand on the virtual image of the pipeline. Heat maps can be used to depict areas of concern along the pipelines, with users able to view the various measurements, such as geological forces, and see changes as they occur over time.

“Such an application simply doesn’t exist in the pipeline industry,” notes Khoo. “If we are able to fully develop this solution, we would consider offering this to the pipeline industry in the interest of improving overall safety.”


Focusing on our failures to make us safer

It might be human nature to try to forget one’s failures or put them in the past, but at Enbridge we regard every incident and near miss as a lesson to be learned and a story to be told and retold.

Our incident investigations drive down to root causes and guide our implementation of effective measures to prevent them from recurring.

And because we want to ensure that we share and remember the hard lessons we learned, we also strive to keep the emotional connection to safety front and center.

To foster a strong culture and ensure that every employee and contractor understands their duty to be safe we regularly take time to stop and engage the team on safety.

This includes daily safety moments and tailgate talks, as well as safety observation programs to promote vigilance on and off the job.

Each year we develop case studies based on recent incidents, focusing on the human factors and failed safety barriers that contributed to them and prompting team discussion.

In addition, each year we pause, as an organization, and take a close look at significant safety failures from our history through our Foundational Safety Stories. The anniversaries of these incidents present an opportunity to remind every member of the team of the human, community and environmental toll of incidents and to reinforce our belief that every incident can be prevented.

By the Numbers


In 2018, we spent more than C$1.1 billion on programs that help us to maintain the fitness of our systems across our operations in Canada and the U.S.

$12.6 M

Last year we invested more than $12 million on advanced leak detection systems to boost our ability to identify small leaks early and respond more quickly and effectively.


In 2018, we carried out 358 inline inspections of our crude oil and natural gas transmission and distribution systems, using sophisticated tools that travel within our pipelines to assess their health, millimeter by millimeter, from the inside out.


Last year Enbridge completed nearly 2,500 preventive maintenance digs across our liquids and natural gas systems, excavating our pipelines to take a closer look, confirm their health and make any repairs, if required.

29,348 and 745,781

In 2018, Enbridge Gas Distribution and Union Gas conducted leak surveys on more than 29,000 kilometers (18,200 miles) of distribution mains in Ontario and Quebec and surveyed more than 745,000 lines used to carry gas from the mains to customers’ residences.