A small volume of liquid natural gas seeped into the atmosphere this month from a "pinhole" opening in an Enbridge Energy Partners LP pipeline in the Upper Peninsula, officials said Tuesday.
The Dec. 8 leak near Manistique was from a pipe known as Line 5, Enbridge spokesman Jason Manshum told The Associated Press. Company workers discovered the leak while performing scheduled maintenance. The opening could not be seen with the naked eye but workers noticed a "wet spot" the size of a dime on a weld where gas had escaped, he said.
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Only a "minuscule" trace was released and immediately vaporized, so there was no environmental damage and no cleanup required, Manshum said.
Line 5 runs from North Dakota to Sarnia, Ontario, and carries both liquid gas and crude oil. It has been targeted by environmental groups because a 4.5-mile segment runs beneath the Straits of Mackinac, where Lakes Huron and Michigan converge. The segment was laid in 1953 and activists contend it's unsafe, which the company denies.
"This small leak is a wake-up call that demands immediate action by our federal and state land management and environmental agencies to publicly disclose the full extent of potential environmental threats posed by this pipeline," said David Holtz, chairman of the Sierra Club's Michigan chapter.
Manshum said Enbridge's handling of the pinhole leak shows the company's maintenance and integrity program is working. He said the leak, which happened about 90 miles west of the Straits area, was fixed and the line is operating normally.
The leak was disclosed Monday to a state task force on pipeline safety. In a statement, Attorney General Bill Schuette and Dan Wyant, director of the Department of Environmental Quality, said the group would "keep a close watch on the status of this incident" and "implement every possible safety precaution to protect the ecology and the economy of the Great Lakes."
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