Explain oil spill, Exxon is urged

Still no reply to water utility

FILE — Exxon Mobil Pipeline workers inspect a split in a section of the Pegasus pipeline in Mayflower on April 15, 2013.
FILE — Exxon Mobil Pipeline workers inspect a split in a section of the Pegasus pipeline in Mayflower on April 15, 2013.

Central Arkansas Water has asked Exxon Mobil if the oil giant knows what caused the Pegasus pipeline to rupture in a Mayflower subdivision almost a year ago and, if so, whether a similar scenario could happen in the Lake Maumelle watershed.

So far, the utility, which oversees the drinking-water supply for about 400,000 central Arkansans, hasn’t received the answers from Exxon Mobil representatives.

“Whether they’re still investigating the cause of the Mayflower [accident] or whether they know and are not sharing, I don’t know and cannot really speculate on that,” Central Arkansas Water spokesman John Tynan said.

Exxon Mobil’s pending proposal to restart the pipeline’s 211-mile southernmost section in Texas raised questions about the Mayflower investigation and about “what process did they go through to rule” out that similar problems existed in that portion, Tynan said. “Of those two questions, we’re more interested in the first.”

During a Feb. 11 conference call, Tynan and John Hart, the utility’s technical services officer, posed those and other questions to Exxon Mobil representatives.

“They said it’s something we can continue to talk about in the future, but [we] didn’t get a timeline,” Tynan said.

“The bottom line is that we still don’t have enough information to know what caused [the rupture in] Mayflower, and we still don’t have enough information to rule out an event similar to Mayflower in the watershed,” Tynan said. “We need to know all the causal factors of Mayflower so that then we can request the appropriate information, as well as tests, to rule out” such an event in the watershed.

The Pegasus, extending about 850 miles from Illinois to the Texas Gulf Coast, has been shut down since shortly after it ruptured March 29 in Mayflower’s Northwoods subdivision and spilled an estimated 210,000 gallons of heavy crude oil into the neighborhood, drainage ditches and a cove of Lake Conway.

On Feb. 6, Exxon Mobil spokesman Aaron Stryk told the Arkansas Democrat-Gazette that the company had filed a request Jan. 31, seeking federal approval to restart the newer, southernmost section of the pipeline at a reduced pressure. The company hopes for a March restart, he said.

The pipeline’s southern section consists of a 205-mile portion between Corsicana and Beaumont, Texas, and a 6-mile segment between Beaumont and Nederland, Texas. Until 2006, those segments operated independently from the rest of the pipeline

Stryk also said Feb. 6 that Exxon Mobil had mostly completed its investigation of what caused the Mayflower accident and that this information would be included in a remedial work plan due April 7 at the federal Pipeline and Hazardous Materials Safety Administration.

In an email interview Feb. 7, Stryk was asked if Exxon Mobil was confident the problems that contributed to the Mayflower accident did not exist in the Texas section and, if they did, if they had been repaired.

Stryk replied, “This is why we are submitting the [restart] request now: because we wanted to complete the investigation and understand what may have contributed to failure in the northern section before restarting the Texas segment. Additionally, we used the time to complete additional external inspections and prepare the Texas segment for restart.”

Late last week, after the Feb. 11 conference call, the Democrat-Gazette asked Exxon Mobil if completion of the investigation meant the company had determined all of the accident’s causes and whether those same problems are present in the Lake Maumelle watershed.

Stryk replied, “All I can say at this time is that we are currently developing the work plan for the northern segment and will address those issues accordingly.”

Neither the federal government nor Exxon Mobil has released copies of the restart plan.

Despite a confidentiality agreement reached in September with Exxon Mobil on sharing pipeline documents, all that Central Arkansas Water has on that restart plan is a one-page fact sheet that Tynan said he got about 4:30 p.m. Feb. 6, roughly the same time Exxon Mobil told the Democrat-Gazette about the plan.

Tynan said, “If the same process were to occur with the northern section [in Arkansas], we would have great concerns. But given that the southern section has not been a focus of ours, we’re not tracking the restart of that as closely as we are” the 13-mile-portion that runs through the watershed.

Still, Tynan said the utility does not believe that the restart plan for the southern section would be an “appropriate model” for the northern section.

“We can’t comment on if that’s appropriate for the southern section,” he said. “But from what we know, that type of plan would not address … the section through here. Much more would need to be done if they plan to restart” the northern segment.

For one thing, Tynan said reduced pressure alone would not suffice in the northern section. The Mayflower pipe segment cracked open at “well below operating pressure” - not only below the pipe’s supposed maximum pressure but also below Exxon Mobil’s self-imposed limit, Tynan noted.

The only other key part of the Texas restart plan that Tynan said he knew of was the oil company’s intention to do in-line inspections, which take place only when a carrier is operating.

Some, including the pipeline administration, have raised questions about how reliably those tools detect cracks.

Stryk has said Exxon Mobil does not plan a hydrostatic, or water-pressure, test on the Texas segment. A pipeline must be shut down when that test takes place.

Tynan said Exxon Mobil has neither committed to nor ruled out a water-pressure test before it restarts the northern section. And it’s unclear to the utility whether Exxon Mobil should perform such a test on the northern part.

“We have been asking questions to determine how accurately and reliably” the in-line tools that Exxon Mobil has been using can identify cracks because cracks were part of what led to the Mayflower rupture, Tynan said.

In July, a laboratory hired by Exxon Mobil to examine the broken pipe segment from Mayflower found manufacturing defects - cracking that the laboratory said likely occurred shortly after the pipe was made in 1947-48 and worsened over time. The industry has known for decades that low-frequency electric resistance welded seams were a problem in some pre-1970s pipe, such as that used throughout most of the Pegasus pipeline but not in the sections proposed for restart.

Richard Kuprewicz, a pipeline safety consultant who is advising Central Arkansas Water, said Monday that “if the inline inspection tools are not really adequate to determine certain crack threats, and that’s kind of what’s coming out here, the hydrotest is the way” to check for them.

Kuprewicz, who is on a technical advisory committee for the federal pipeline agency, said “the real issue is” whether the in-line tools can accurately identify crack threats. “If they can, they need to demonstrate that,” he said of Exxon Mobil officials. “If they can’t, they probably should have a hydrotest,” which he called “a very good judge of cracks” when it’s performed properly.

Kuprewicz said, “There may be a concern that the line would not pass a hydrotest,” however.

Kuprewicz said he would not be too worried about a hydrostatic test failure in a single pipe section. But he said, “If they get multiple hydrotest failures,” that would suggest “a systematic problem in the pipeline.”

Exxon Mobil last hydrotested the Pegasus in 2005-06. A May 10 letter from the pipeline administration to Exxon Mobil Pipeline Co., an Exxon Mobil Corp. subsidiary, said the 2005-06 test found 11 seam failures in the line’s northern section, compared with a 205-mile segment of the southern section, which had just one seam failure during a more stressful pressure test in 1991.

Further, the northern section has “12 confirmed seam cracks identified during an in-line seam assessment in 2010,” while the southern section “did not have any weld cracks or preferential seam corrosion identified by an in-line inspection in 2003-2004,” the letter added.

An administration official also had “noted there was uncertainty with regard to the in-line assessments which had previously missed identifying anomalies or potential threats at the locations of the seam failures,” the letter said. According to the letter, Exxon Mobil reported that the 2010 inspection found “no significant anomalies in the area of [the] failure site” in Mayflower.

Front Section, Pages 1 on 02/18/2014

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