Straits pipeline report raises fears of disaster; Enbridge says oil, gas lines supported Previously undisclosed 2003 inspection found long stretches of underwater pipeline lost span supports

Keith Matheny | Detroit Free Press

Show Caption Hide Caption Did improper mooring damage Straits oil pipeline? Sixteen sections of underwater oil and gas pipelines in the Straits of Mackinac were found unsupported on the Great Lakes bottom during 2003 inspections — spans of 140 feet or longer, well beyond state requirements for mooring the pipe.

Sixteen sections of underwater oil and gas pipelines in the Straits of Mackinac were found unsupported on the Great Lakes bottom during 2003 inspections — spans of 140 feet or longer, well beyond state requirements for mooring the pipe.

That revelation was made in an October 2016 report by a contracted engineer for the pipeline's owner, Canadian oil-transport giant Enbridge. It means the 64-year-old pipes were jostled by powerful, shifting currents, without support, for an unknown period of time, possibly years, subjecting the pipes to stresses the supports are designed to help alleviate as the pipes flexed back and forth.

The Free Press reviewed a copy of the 2016 report that previously had not been made public.

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The pipeline, known as Line 5, carries up to 23 million gallons per day of crude oil and liquid natural gas through the Upper Peninsula before splitting at the Straits into twin, 20-inch, underwater pipes for the 5-mile stretch between the Upper and Lower Peninsulas. It then reunites into a single transmission line to move the products south through the state before reaching a hub in Sarnia, Ontario, in Canada.

Enbridge's original 1953 easement with the State of Michigan allowing the underwater pipelines required span supports spaced no greater than 75 feet apart. The largest unsupported span discovered during 2003 underwater inspections was 286 feet, the report by Kiefner and Associates for Enbridge states.

"It’s so far outside anything that I contemplated, or anything that was known. ... It’s just incredibly negligent of Enbridge to have let that happen," said Edward Timm, a retired Dow Chemical engineer. He has studied the Straits pipeline and its safety concerns over the past three years in conjunction with the nonprofit environmental group For Love of Water, or FLOW.

"The pipe has taken a hell of a beating, and we don't know how much of a beating."

The supports, which in some instances are simply stacked sacks of grout on which the pipes rest, were presumably washed away by underwater currents.

Enbridge spokesman Ryan Duffy on Thursday emphasized that discovered problems were corrected, and that the Straits pipelines "are in full compliance with our easement agreement with the state."

"Data from our inspections shows that the longer span lengths did not affect the integrity of the twin pipelines," he said, adding that a review by the federal Pipeline and Hazardous Material Safety Administration of 20 years of Line 5 data "confirmed that Line 5 is in good condition."

Duffy did not respond to questions about how long the unsupported spans may have existed or whether state officials were informed about them, either at the time they were discovered and corrected or during the state Attorney General's Office's recent inquiries about the Straits pipelines.

Environmentalists concerned

The findings in the report set off alarms for those concerned that an oil spill from the pipelines in the area where Lakes Michigan and Huron join — and currents often flow east and west in the same day — would be a disaster for the lakes and shoreline communities dependent on them.

A 2016 University of Michigan study found that more than 700 miles of Great Lakes shoreline, from Saginaw Bay in Lake Huron to near Traverse City on the Lake Michigan side, could be exposed to oil from a Line 5 spill in the Straits, depending on the amount of oil spilled and how currents were flowing.

The revelation of long, unsupported pipeline spans for possibly years "really raises serious questions — not just about the integrity of the pipeline, but Enbridge’s failure to honor its agreement with the state to maintain the pipeline," said Michigan Sierra Club Chairman David Holtz.

The information in the reports underscore that the pipeline is a high risk to Michigan and Great Lakes communities, said Beth Wallace, a pipeline safety specialist with the nonprofit National Wildlife Federation's Great Lakes Regional Center.

"Enbridge continues to not disclose critical information until their hand is forced — they should have notified the state immediately after discovering this major violation of the easement," she said.

A state Pipeline Safety Advisory Board commissioned by Gov. Rick Snyder is awaiting commissioned studies of potential worst-case-scenario impacts from a Line 5 spill and possible routes, other than through the Straits, to deliver the oil and gas.

Was fixing problem enough?

The Kiefner report states Enbridge conducted underwater surveys of Line 5's condition in 2001 and 2003, conducted by Onyx Superior Special Services. They included side-scan and multibeam sonar imaging, followed by a video examination using a remotely operated vehicle.

"The sonar imaging revealed the free lengths of exposed spans on the Straits bottom," the report states. "The 2003 survey identified seven spans longer than 140 feet in the east leg, with the longest being 224 feet, and nine spans longer than 140 feet in the west leg, with the longest being 286 feet (due to a failed grout bag support)."

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The report adds that all spans exceeding 140 feet were corrected by Enbridge using screw anchor supports.

The report notes that the original design specifications for Line 5 called for spans not to exceed 140 feet, with the 75-foot agreement with the state being a matter of "additional conservatism in order to allow for unanticipated conditions or changes in conditions during operation."

American Society of Mechanical Engineers standards for offshore liquid pipelines call for limiting longitudinal stresses on a pipe to 80% of "specified minimum yield strength," an indication of the minimum stress a pipe may experience before permanent deformation may be caused. The Kiefner report found that limit on the underwater portions of Line 5 "is achieved at a span length of 155 feet," meaning a number of the unsupported spans in 2003 were exposed to stresses that went beyond the accepted standard at which permanent pipe deformation can occur.

The Kiefner report, however, seemed to downplay the concerns of any possible weakening of the underwater pipelines.

"The conclusion that longer spans can remain safe is logically supported by recognition that longer spans have historically occurred with no apparent distress to the pipeline, although Enbridge prudently took steps to correct spans in those instances," the report states.

Lawmakers seek change

Problems with washed-away pipeline supports have continued. Enbridge in July 2016 requested permission from the state to install 22 additional supports on Line 5, including four required to bring the pipes back into compliance with 75-foot support spacing requirements. State officials in October 2016 approved installing the four supports but rejected installation of the other 18, citing a desire to await the findings of the studies commissioned by the Pipeline Safety Advisory Board that might clarify the future of the Straits pipeline.

Michigan's U.S. Democratic Sens. Gary Peters and Debbie Stabenow, who were touring the Soo Locks in Sault Ste. Marie on Thursday, expressed concern over the 2003 Line 5 support problems.

"The amount of water that goes through the Straits is equal to 10 times that of Niagara Falls," Peters said. "So there’s tremendous pressure going through the Straits, and that’s why a pipeline needs to be secured, and supports have to be properly positioned. And as a pipeline gets older — and this pipeline is in excess of 60 years old — having it not secured properly increases the potential for a catastrophe."

A bill sponsored by Peters in the Senate became law in 2016, making the Great Lakes designated as a high consequence and unusually sensitive area subject to higher standards for operating pipelines safely. The law also requires pipeline operators to better lay out plans for how to address an oil spill during periods of ice cover, and adds requirements of reviews of pipelines for age and integrity.

Peters and Stabenow also cosponsored a bill last week that would raise liability caps for Great Lakes pipeline operators, expand and clarify the U.S. Secretary of Transportation’s authority to suspend or shut down unsafe oil pipelines, strengthen federal review and increase transparency surrounding oil spill response and cleanup plans and create a Center for Expertise in the Great Lakes region to study freshwater oil spills.

"We are doing everything we possibly can to tighten up the pipeline safety laws," Stabenow said. "As somebody who loves the Great Lakes, like we all do, it is not acceptable for this pipeline to be there and not be 1,000% secured and safe."

Contact Keith Matheny: 313-222-5021 or kmatheny@freepress.com. Staff writer Kathleen Gray contributed to this report.