Enbridge: Under pressure

It began with an alarm. Enbridge's control room in Edmonton is the nerve centre of the world's most extensive pipeline system, receiving real-time data on pressure, temperature and volume of numerous batches of crude oil and other hydrocarbons from across North America. It's the nexus of a sophisticated system known as a Supervisory Control and Data Acquisition (SCADA), and it generates so many complex charts and other data that workers there often sit in front of six or more LCD displays. High-pitched klaxons warn operators of anomalies in the line thousands of kilometres away, allowing them to stop pumps and seal off valves if necessary. And at 3:58 p.m. local time on July 25, one of them sounded insistently.

At that very moment, Enbridge was taking a tributary of its vast network, a 500-kilometre segment of aging 30-inch pipe known as Line 6B, offline for 10 hours. It carries various grades of crude oil from Griffith, Ind., to Sarnia, Ont, supplying refineries along its length. The alarm signalled an abrupt pressure drop at one of 6B's pumping stations, in Marshall, Mich., triggering an automatic shutdown. Another alarm sounded five minutes later, indicating a discrepancy between the volume of oil entering 6B at Griffith and that detected downstream in Marshall.

Crudely put, leak detection works on the principle that what goes in must come out. After studying the SCADA data, Enbridge employees concluded a vapour cavity had formed inside 6B. Known as "column separation" or "slack line" in industry jargon, it occurs when pressure inside the line drops below the pressure at which the liquid evaporates. The resulting gas bubble can impede the flow of oil. They figured the problem would persist until restart.

They'd just made the biggest mistake of their careers. Line 6B had in fact ruptured and was oozing tens of thousands of barrels of tarsands crude into a creek. It was a critical moment in a year of awful mishaps, which included a 6,100-barrel spill in Romeoville, Ill., and 3,000 barrels near Neche, N.D. Now politicians and regulators are on the warpath. Perhaps the only solace is that the worst recent incident belonged to someone else: the fatal Sept. 9 explosion of a Pacific Gas & Electric Co. natural gas transmission line in San Bruno, Calif. "I don't think anyone can look at what has happened in Michigan or California and conclude that our pipeline safety laws are working as intended," said Henry Waxman, chairman of the Committee on Energy and Commerce, at a hearing in September.

All this might complicate Enbridge's ambitions. Its liquids network links Alberta's tarsands with American refineries and consumers; it delivers well over half of Western Canada's crude to market and satisfies 12% of America's insatiable demand for imported oil -- more than either Saudi Arabia or Venezuela. And Enbridge is investing billions on the biggest construction binge in its history. In a rush to lay new pipes, did Enbridge neglect its old ones?

Though it's easy to forget in times like this, pipelines are the safest and cheapest method of transporting crude. They've eclipsed oil tankers, rail and tanker trucks to become the dominant method of meeting America's ravenous demand. And over the decades, they've shown steady safety improvements, reducing both the number of incidents and the volumes spilled, even as more pipeline was laid. Enbridge deems itself better than most. "Our level of spills is about 40% of the industry average," CEO Patrick Daniel told a hearing into the Michigan and Illinois incidents in September. "Based on the miles of pipeline we operate, our line break rate is roughly half of the industry average."

Nevertheless, pipelines are constantly threatened. Although disgruntled individuals can and do blow up pipelines, in North America the primary hazard is a bonehead with a backhoe. And since virtually all pipelines are made of steel, operators must be watchful for corrosion. Lines are inspected regularly. "Smart pigs," articulated caterpillar-like devices that travel inside pipelines, sometimes include magnetic-flux leakage tools that help find corrosion and pitting by magnetizing the steel and looking for telltale "leaks" in the magnetic field. Pigs can also find cracks by emitting ultrasonic signals and analysing the returning echoes.

According to regulatory documents, in 2007 Enbridge conducted magflux inspections on 6B, which identified 140 corrosion defects. Regulations presented two choices: fix them within 180 days, or increase the margin of safety by reducing pressure on the line. In June 2009, another inspection (this one using ultrasonic technology) found 250 more defects. (As for the site of the subsequent rupture, Enbridge says it found only minor metal loss, well within regulatory tolerances.)

In both instances the company fixed just a handful, opting instead to reduce pressure. As a result, by this summer Line 6B contained 329 known defects. Partly, this backlog developed as Enbridge pondered whether it should fix them or replace large sections of pipe instead. There was little urgency: by the company's reckoning, it would take more than a decade for any of these defects to grow into a leak. On July 15 the company asked the Pipeline and Hazardous Materials Safety Administration (an arm of the U.S. Department of Transportation) for permission to maintain reduced pressure on 6B until late 2012. Events 10 days later cast this request in a dark light.

What exactly happened in Marshall during the evening of July 25 is still being sorted out. But it seems that at some point that day, Line 6B ruptured little more than a kilometre south of town. Hours after it was first taken offline, the Calhoun County Dispatch Center received two 911 calls complaining of strong odours. One caller described smelling something like natural gas.

Oblivious, a new shift in Enbridge's Edmonton control room attempted to restart the line on schedule at 2 a.m. the following morning. Its members still thought they were dealing with column separation. One way to overcome that is by "packing the line" with more oil. They fired up pumps in Griffith, Ind. Eight minutes later, an alarm sounded, indicating a flow imbalance between there and the Marshall station. "Filling a slack line renders most pipeline leak detection systems nearly useless," observes Tom Miesner, an industry veteran and author of Oil and Gas Pipelines in Nontechnical Language who served as president of Conoco Pipeline for six years. "As with a leak, less is coming out the end than is going in." Enbridge's employees faced conflicting information -- at one point, a slight pressure increase within the line suggested the separation was being overcome. But pressure continued falling further downstream. Unable to overcome their imaginary foe, they shut down 6B for the final time at 5:55 a.m.

Hours later, the control centre dispatched a local technician to the Marshall station in search of leaks. He walked around the perimeter, found nothing, and departed. He was less than two kilometres from a gruesome discovery: Tarsands crude saturated about two hectares of land, leached through the soil, drained into a culvert and into a local watercourse called Talmadge Creek. (Line 6B spilled an estimated 19,500 barrels of something called "Cold Lake Blend." It's tarsands bitumen originating from ExxonMobil's production field in Cold Lake, Alta., about 300 km northeast of Edmonton, mixed with diluent to improve flow.) By then, locals 15 km away smelled it. Beset by complaints, the local natural gas utility sent its own technician who found oil in Talmadge Creek. The utility called Edmonton and relayed the news. Enbridge's nightmare had begun.

The smell hit Jeff Kimble about a mile away from Talmadge Creek. An on-scene co-ordinator with the U.S. Environmental Protection Agency, he drove his truck to Marshall to join the emergency response. His windows were up, but there "was a pretty good odour threshold -- you could smell the oil," he says. Kimble drove to Division Street, which crosses over the creek. It was fouled from bank to bank. "All I could see was oil," he recalls. Nearby, local fire departments busily deployed booms across the river to contain the oil, and desperately searched for a vacuum truck to collect it.

Nature worked against them. Heavy rainfall caused flooding of a magnitude witnessed less than once every quarter century. Waters moved high and fast, carrying crude down Talmadge Creek into the Kalamazoo River. Normally it might have stopped at an old hydroelectric facility called Ceresco Dam, but not under these conditions. Kimble phoned colleague Mark Durno, deputy incident commander with the EPA. "This is the biggest spill I've ever seen," he told Durno. "We're going to need a lot of responders." Later, he likened its magnitude to other crises the EPA has worked on over the past decade: 9/11, Hurricane Katrina, BP's Gulf of Mexico spill and the space shuttle Columbia crash.

Other agencies rushed to the scene. Enbridge had called in the spill to the National Response Center, which in turn notified 16 other federal, state and local agencies. The National Transportation Safety Board dispatched four investigators to Marshall, another to Edmonton, to begin a formal probe. The National Guard and Coast Guard sent personnel, as did the U.S. Fish & Wildlife Service. Kimble got on the blower to find out how many people Enbridge was sending -- and then ordered it to send more. Soon Marshall crawled with more than 2,000 government officials, Enbridge employees and contractors from as far away as Edmonton and Houston, more than doubling the town's population. Among them was Patrick Daniel, Enbridge's CEO, who stayed more than two months and boldly promised "to clean up anything and everything that the oil touched along the way."

Organizations that previously had little or no contact with one another had to learn to work together, and quickly. Booms eventually halted the crude's progress about 50 km down the Kalamazoo River. Within a week, most of it had been contained and removed, leaving a multi-hued sheen, similar to that on a parking lot after rain. Wildlife was cleaned and released -- most of it survived. Air quality improved dramatically. The spill site was excavated, and the emergency ended within a few weeks.

Then came the cleanup. The floodwaters receded, leaving oil-coated floodplains and bathtub-like rings of oily scum on trees and river banks. Seen from above, fouled islands trailed large plumes downstream -- the remainder of the oil took months to clean. Some remains, but the EPA hopes it will biodegrade naturally, and the cleanup is now nearly complete. Grasses were planted to stabilize the creek shoreline, and submerged oil removed. The EPA describes Enbridge's cleanup performance as "solid."

It took nine weeks, though, to restart 6B. Every day of outage is costly, and not just in terms of lost tolls. With a major oil artery between Canada and the U.S. blocked, oil piled up in Canada. Major producers such as Imperial Oil and Cenovus faced a glut; prices dropped. Meanwhile, U.S. refineries starved for crude. Enbridge promptly filed a restart plan with PHMSA, but that was rebuked as inadequate. It was able to shift some capacity to other lines, and persuaded PHMSA to allow 6B's restart in late September, albeit at even lower pressures than before. But local congressman Mark Schauer opposed the move, saying he had "no confidence" Enbridge could operate the line safely.

Enbridge must foot the up-front bill for its spill. In its most recent quarterly report, though, the company disclosed that the Michigan and Illinois spills may cost only $85 million. Much of that will be covered by third-party liability insurance. Meanwhile, the company's ambitions remain undimmed. Speaking on a conference call from Battle Creek, Mich., just days after the spill, CEO Patrick Daniel declared: "We expect to continue to aggressively expand and grow" in the U.S.

Might recent spills complicate those plans? That may depend on what's happening in Ashburn, Va. The ruptured segment from Line 6B now lies in a hangar-like facility there, along with undamaged adjoining segments. (A 12-foot segment from the 6A Romeoville spill also went there.) Metallurgists, mechanical engineers and materials scientists are studying them with optical and electron microscopes and other tools, in hopes of reverse-engineering the six-foot-long gash. "There are certain features that we look for in a fracture surface that indicate the direction in which the crack originated from," explains Joseph Kolly, director of NTSB's research and engineering office. "You work backwards from those features until you find where the origin location is." They'll torture the pipe until it confesses.

That's just one part of a multi-faceted investigation not dissimilar to NTSB's more prominent inquiries into jet liner crashes, which also includes poring over Enbridge's SCADA data. "The SCADA system is analogous to the black box on an airplane," says Robert Trainor, chief of NTSB's pipeline and hazardous materials investigations. Many questions remain unanswered. Why, for instance, did the Edmonton control centre misdiagnose the alarms? Inadequate training, fatigue and shortcomings in how SCADA data are displayed has contributed to previous spills. "We have no reason to believe there weren't column separations," says Trainor, "but we also want to know if there were other indications that suggested something else was happening."

Are Enbridge's pipes simply getting too old? 6B was built in 1969; other segments that failed recently dated from the '50s. The industry emphasizes that properly maintained pipelines last indefinitely, but regulators are beginning to wonder. Corrine Brown, chair of the Subcommittee on Railroads, Pipelines, and Hazardous Materials, recently testified that "much like the sewer and water infrastructure in this country, much of the pipeline infrastructure is reaching the end of its useful life." If that view prevails, Enbridge may soon find itself replacing large segments of old pipe instead of laying new lines.

Coming just days before a catastrophic failure, the company's request for a 2-1/2-year grace period to fix 6B looks bad. It also seems unusual: according to PHMSA's Office of Pipeline Safety, most operators of hazardous liquid pipelines do better. In a study published in 2006, it studied 409 "integrity threats" found on hazardous liquid pipelines and found that 98% of the necessary repairs were completed within regulatory time frames. "Enbridge knew about hundreds of defects in the line," fumed James Oberstar, chairman of the Committee on Transportation and Infrastructure, at a hearing. "PHMSA was made aware of them and failed to do anything to address Enbridge's inaction. That is not a culture of safety."

ProPublica, an investigative journalism outfit, recently accused BP of fostering a culture of austerity that included cheaping out on pipeline maintenance, resulting in spills and explosions. Some evidence, however, suggests Enbridge did not go down that path. According to annual reports the company filed with the Federal Energy Regulatory Commission, Enbridge's spending on operating and maintaining its lines grew steadily during the past five years -- not only in nominal terms, but also in relation to its growing line mileage and volumes transmitted. For his part, Daniel recently claimed Enbridge has always "focused on safely operating the assets that we've got." And his handling of the Michigan spill contrasts strikingly with former BP CEO Tony Hayward's response to the Gulf disaster.

NTSB's final report is likely at least a year off. But besieged by accusations PHMSA went soft on Enbridge, its overlords at the U.S. Department of Transportation are already talking tough. "I am deeply troubled by Enbridge's detection of and response to this oil spill," said John Porcari, the deputy secretary of transportation, at a hearing in September. PHMSA forcefully rejected Enbridge's request for a 2-1/2-year extension to fix 6B's outstanding anomalies, and the company finds itself in a sort of regulatory purgatory -- hardly an ideal position from which to pursue new project approvals.

Beyond the regulatory maelstrom, though, pipelines remain the favoured pack mule of America's petroleum transportation system. America's crude oil production has fallen steadily since 1970, so new pipes from the tarsands provide welcome supply. Recently, U.S. Secretary of State Hillary Clinton indicated the Obama administration is "inclined" to approve TransCanada's proposed Keystone XL pipeline, which would span from Alberta to Texas. "We're either going to be dependent on dirty oil from the Gulf or dirty oil from Canada," she said. The secrets coughed up by 6B's burst segment may have great bearing on how Enbridge's future proposals are received.