Natural gas liquids can flow again through Sunoco Pipeline L.P.’s Mariner East 1 pipeline, the Pennsylvania Public Utility Commission said Thursday, concluding the line is safe to use after sinkholes related to the construction of parallel pipelines threatened to destabilize it.
The five utility commissioners voted unanimously to lift their emergency shutdown order on the same day that the state Department of Environmental Protection fined Sunoco $355,000 for violations at its associated Mariner East 2 pipeline construction project.
Mariner East 1 has been shut down since March 7, when subsided ground in West Whiteland, Chester County, exposed the active pipeline, creating a safety threat in a residential neighborhood.
The utility commission’s investigation bureau recommended last Friday that Sunoco be allowed to resume service on the line because inspectors were “satisfied that the integrity of that active pipeline had not been compromised by the recent subsidence events.”
The investigation included tests of the pipeline and the surrounding geology. The enforcement plan calls for ongoing monitoring at the site for six months after construction is finished.
An 87-year-old former petroleum products pipeline, Mariner East 1 was repurposed and reversed in 2014 to bring ethane and propane from Marcellus and Utica shale wells to the East Coast.
The sinkholes emerged during construction of Sunoco’s sister pipelines, Mariner East 2 and 2X, which have also muddied protected waterways and disrupted drinking water supplies along their route.
The DEP fine Thursday addresses different violations than those covered by a $12.6 million fine the department levied against the company in February.
The new penalty is for drilling fluid spills to wetlands, wild trout streams, and high-quality waterways in Allegheny, Blair, Cambria, Cumberland, Dauphin, Huntingdon, Indiana, Lancaster and Washington counties over the last year, DEP said.
The nearly two-month shutdown of Mariner East 1 forced Western Pennsylvania gas producers to find other outlets for their ethane, by blending more of it into their natural gas pipelines or shipping it through pipelines to other regions.
Companies that use the pipeline’s products — including regional propane suppliers and Dominion Energy’s Cove Point natural gas liquefaction and export terminal in Maryland — had urged the PUC to allow Sunoco to restart operations.
West Whiteland, local homeowners, environmental groups and state Sen. Andrew Dinniman, D-Chester, opposed allowing Sunoco to resume flows on the line, at least until the underlying studies were released and could be independently reviewed.
The subsidences spurred Sunoco to temporarily relocate several affected families during the investigation.
Lisa Dillinger, spokeswoman for Sunoco Pipeline owner Energy Transfer Partners, said procedures to restart service on Mariner East 1 will begin immediately.
Laura Legere: llegere@post-gazette.com.
First Published: May 3, 2018, 4:12 p.m.
