Millennium Pipeline has been given the go-ahead to return to full service, company officials said, after a natural gas leak led to a government investigation that uncovered missing weld inspection records. While the records weren’t located, new weld inspections were conducted to verify the integrity of four “suspect” welds that raised the ire of federal officials for inadequate paperwork.
“Our integrity confirmations revealed that no additional anomalies were found, no weld defects of any kind were found. Our digs didn’t reveal anything out of the ordinary or unusual to be of concern.”
State and federal officials launched an investigation into the pipeline after a weld, located near the Broome-Tioga county border, sprung a leak on Jan. 11. The leak released an estimated 1.3 million cubic of feet of natural gas — enough to heat an average home in the Northeast for 18 years — before repairs were completed five days later.
The results of that investigation were released in a U.S. Pipeline and Hazardous Materials Safety Administration document in July, which pointed to the three other welds in a 93-mile section of the Millennium system that were considered “suspect” because of missing inspection documents.
Between the leak and the recordkeeping deficiencies, the July PHMSA document expressed concerns about the integrity of the pipeline as a whole.
“Similar defects may also develop leaks and potentially lead to a rupture of the pipeline,” the federal document said.
Following the report, Millennium reduced pressure on the pipeline — which can reach a maximum of 1,200 pounds per square inch, but is normally lower — by 20 percent until the integrity of the welds could be verified.
On Sept. 21, Millennium and PHMSA reached a consent agreement, in which they agreed to conduct new testing to allay concerns about the welds by Dec. 31.
The consent agreement document identifies the “suspect” welds with approximate locations that would place all four in either western Tioga or eastern Broome counties.
Gibbon said the work was completed recently, and Millennium was given the green light to return to normal pressure in mid-October.
An estimated $500,000 to $600,000 in “pig testing” — a process in which camera equipment is shuttled through the pipeline to collect data from the inside — in addition to nine investigative digs provided information that was missing in the records.
The welds turned out to be OK, according to Gibbon.
“There were different places along the pipeline where they asked if we would please go through and get a visual to make sure that everything is okay, and it was” she said. “We submitted our findings back to PHMSA … and we’ve returned to normal pressures.”
‘Not a perfect system’
Richard Kuprewicz, a Bellingham, Wash.-based pipeline safety expert, said situations such as this are “not unusual.”
Pipeline operators are not required to conduct an X-ray inspection of every weld on a pipeline, even though it’s the best way to ensure the integrity of a weld.
On top of that, government agencies don’t typically look over the shoulder of pipeline operators during construction to make sure every single weld has an inspection record.
“Everyone thinks, especially during the construction, that there’s safety inspectors looking at this every step of the way,” he said. “They can’t be checking every weld or every record. There’s only a certain number of people.”
Case in point: Although the Millennium Pipeline gained government approval prior to going online in December 2008, PHMSA became aware of recordkeeping deficiencies only after the January leak.
“It’s not like it’s your car being built and there are quality controls,” Kuprewicz said. “It’s not a perfect system.”
Gibbon said Millennium takes “full responsibility” for the missing records, and has both revised its recordkeeping system and launched its own internal investigation.
“Even though we have modernized our system going forward, we’re going back and doing a very careful examination of where something could have slipped through the cracks,” she said.
PHMSA did not respond on Monday to questions about the agency’s records on inspection policies.