EXPLAINER | Mariner East: A pipeline project plagued by mishaps and delays
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Mariner East: A pipeline project plagued by mishaps and delays

Jon Hurdle / StateImpact PA

A Mariner East 2 construction site in rural Pennsylvania. The Public Utility Commission lifted a ban on construction of a valve, removing one obstacle to completion of the troubled project.

Sunoco Logistics Mariner East pipeline project includes three lines — the Mariner East 1, the Mariner East 2, and the Mariner East 2X, all of which carry or will soon carry natural gas liquids (NGLs) from the Marcellus and Utica Shale plays in eastern Ohio and western Pennsylvania across the state to a processing and export terminal in Marcus Hook, Delaware County.

In 2014, Sunoco completed its conversion of a gasoline pipeline originally built in the 1930’s to ship gas from Philadelphia area refineries to rural Pennsylvania. Reversing the flow of the 8-inch line, Sunoco’s Mariner East 1 now carries NGLs across Pennsylvania to its suburban Philadelphia facility where it is shipped overseas to manufacture plastics.

The Mariner East 2 would expand capacity to 345,000 barrels of NGLs a day. The 20-inch diameter high pressure pipeline tunnels beneath 17 counties, cuts through 2,700 properties with a 50-foot right-of-way, and crosses more than 1,200 streams or wetlands. The company used eminent domain procedings to secure right-of-ways from reluctant landowners, including one family in Huntingdon County that sat in their trees to protest the pipeline construction. Dozens of landowners are still tied up in litigation with the company and the state Supreme Court could decide to hear the cases.

Construction on the $2.5 billion project began in February 2017, after the Department of Environmental Protection identified hundreds of deficiencies in its water-crossing and earth-moving permits. Since then the DEP has issued more than 60 violations to the company for polluting wetlands, waterways, and destroying about a dozen private water wells. In the summer of 2017, DEP, along with several environmental groups, agreed to a consent decree with Sunoco after dozens of drilling mud spills led to the pollution of high value wetlands and trout streams, and the loss of drinking water for residents of a Chester County community.

In April, 2017 Sunoco Logistics merged with Energy Transfer Partners, the builder of the controversial Dakota Access line. Completion of the line is now about 18 months behind its original schedule. The Mariner East 2X is a 16-inch NGL line that will run parallel to the ME2.

In March 2018 Pennsylvania’s Public Utility Commission ordered a temporary shutdown of the Mariner East 1, saying it could have a “catastrophic” effect on public safety if it leaks. The commission said the pipeline had been exposed by the appearance of sinkholes near the construction of the two other Mariner pipelines. On May 3, 2018 the PUC allowed NGLs to flow through the pipeline after their inspectors reported the sinkholes did not pose a threat to public safety.

In mid-December 2018, Chester County’s district attorney opened a criminal investigation into the pipeline project, saying the sinkholes at Lisa Drive show that the project has endangered life and property. As part of the probe, he impaneled a grand jury. Sunoco called the allegations “baseless” and said it is “confident that we have not acted to violate any criminal laws in the Commonwealth of Pennsylvania.”

A hybrid Mariner East 2 line went into service at the end of December 2018. It was planned as a 20-inch cross-state pipeline. But because the full length of the 20-inch line will not be finished until 2020, Energy Transfer has said, the company will join three different pipelines to create a line through which natural gas liquids will flow temporarily.

In March 2019, the Delaware County district attorney and the state attorney general’s office began a criminal investigation of the pipeline project. Sunoco once again said there is no basis for an investigation.

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Energy Transfer, the parent company of Mariner East 2 pipeline builder, Sunoco, works at Snitz Creek in West Cornwall Township, Lebanon County after a drilling mud spill during the summer.
Updated: June 15, 2019 | 4:24 pm

PUC launches review of safety regulations on hazardous liquids pipelines 

The commission didn’t name specific projects. But it has come under criticism from people who say it hasn’t done enough to ensure the safety of the Mariner East project, which is transporting highly volatile natural gas liquids across the state.

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A sinkhole that opened up in January was surrounded by orange plastic fencing outside a suburban home at Lisa Drive in West Whiteland Township, Chester County.
Updated: May 2, 2019 | 5:40 pm

Chester County state representative faces backlash for bringing Nazis into pipeline debate

Danielle Friel Otten said she wasn’t comparing pipeline workers to Nazis. Many others say that’s what she did. She apologized on Thursday.

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In this file photo, Mariner East 2 pipeline construction crews work in the backyards of homes on Lisa Drive in West Whiteland Township, Chester County, on May 2, 2018 after sinkholes opened in the area. That caused one of the ME2 project's many delays.
Updated: April 30, 2019 | 11:48 am

Sunoco buys two homes at Chester County site of Mariner East 2-related sinkhole

State and county documents show company paid $400,000 each for properties
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A Mariner East pipeline construction clearing in Delaware County.

Suburban Philadelphia state senators seek answers from DEP chief over Mariner East pipeline

The lawmakers say Patrick McDonnell's re-appointment should be delayed until pipeline investigations are complete
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Crews work at the site of a sinkhole along the Mariner East pipeline route near the Pennsylvania State Police barracks on Route 1 in Delaware County on Thursday, April 25, 2019. Pipeline builder said there were no leaks and no pipelines were exposed.
Updated: April 25, 2019 | 2:54 pm

Sinkhole opens up along ME2 route in Delaware County; no leaks or injuries

Sunoco says hole has been filled and pipeline operations continue
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Mariner East 2 pipeline construction in Lebanon County August 24, 2018

Energy Transfer is under criminal investigation for Mariner East pipelines, and now a prominent GOP legislator is criticizing the company

State Sen. Gene Yaw, a staunch supporter of Pennsylvania’s gas industry, said Energy Transfer is damaging the reputations of more responsible pipeline operators.

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Mariner East 2 pipeline construction in Delaware County. The project spans multiple counties, including neighboring Chester and Berks.
Updated: April 4, 2019 | 2:59 pm

Sunoco agrees to settlement, including more safety inspections, with PUC investigators after Mariner East 1 leak

If approved, company will pay $200,000 fine and step up safety inspections of ageing pipeline
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Mariner East 2 pipeline construction crews work in the backyards of homes on Lisa Drive in West Whiteland Township, Chester County, on May 2. Sinkholes that opened in the area prompted the state's Public Utility Commission to order that an existing pipeline nearby, the Mariner East 1, be shut down until it could be determined that the sinkholes didn't threaten its safety. PUC on May 3 approved a re-start of Mariner East 1.

Chester County plaintiffs settle class-action suit with Sunoco over Mariner East

Company denied claims of negligence during pipeline construction at Lisa Drive
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Sunoco's Mariner East 2 pipeline construction on Pennell Road in Middletown Township. (Emma Lee/WHYY)

Higher operating pressure prompts new safety concerns over Sunoco’s Mariner East 2X pipeline

Documents indicate Sunoco has a new maximum operating pressure for the line, which is under construction. An engineer who conducted a risk assessment of the Mariner East project said a higher pressure increases risk.

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Tree-clearing in Delaware County to prepare for the construction of the Mariner East 2 pipeline project. The builder, Sunoco Logistics, rejected an attempt by a township in neighboring Chester County to block the installation of a valve along the line.

State attorney general, Delaware County district attorney launch criminal investigation into Sunoco, Energy Transfer

Chester County’s district attorney is already investigating the Mariner East pipeline project. The company said it will “aggressively” defend itself.

By Susan Phillips
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