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 NGL’s to flow through the pipeline after their inspectors reported the sink holes did not pose a threat to public safety.

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Construction on the Mariner East 2 pipeline has faced myriad problems, including damaged water supplies and sinkholes in a residential neighborhood in Chester County.

DEP fines Sunoco for damaging drinking water in Berks, Chester and Lebanon counties in 2017

Construction of the Mariner East 2 pipeline resulted in cloudy water for some; others lost use of their wells
By Susan Phillips

Ellen Gerhart has been battling with Sunoco Logistics over the construction of the Mariner East 2 pipeline on their property in Huntingdon County, Pennsylvania.

Mariner East 2 pipeline opponent jailed, fined for violating court order

Pipeline opponent Ellen Gerhart must pay $2,000 fine, and spend two-six months in jail.

By Marie Cusick

Sunoco's Mariner East 2 pipeline construction on Pennell Road in Middletown Township. (Emma Lee/WHYY)

PUC allows restart of Mariner East 2 construction in parts of Chester County

The agency agreed to have Sunoco continue construction at eight of 12 locations, where a judge halted work due to public safety and environmental concerns.

By Susan Phillips

Construction on the Mariner East 2 pipeline has faced myriad problems, including damaged water supplies and sinkholes in a residential neighborhood in Chester County.

DEP reaches settlement with environmental groups over Mariner East 2 pipeline

The agency is agreeing to do more to enhance public participation around pipeline projects
By Marie Cusick

The Mariner East 1 natural gas liquids pipeline has been exposed in a creek near a housing development in Uwchlan Township, Chester County.
Updated: July 20, 2018 | 1:48 pm

Sunoco: Exposed pipe in Uwchlan Township is inactive, not Mariner East 1

A township supervisor said Thursday that a township engineer had confirmed the line was part of Mariner East 1. But Sunoco said today that the line was taken out of service in 2015.

By Jon Hurdle

Mariner East 2 pipeline construction in Chester County
Updated: July 20, 2018 | 11:15 am

New Mariner East troubles: Spill in western Pa., exposed pipeline outside Philadelphia

The state’s Public Utility Commission said people are not in “imminent danger” from the exposed pipe. But a township supervisor said she’s concerned and wants the situation treated with urgency.

By Jon Hurdle

A sign marks the path of the Mariner East 1 pipeline through Chester County.
Updated: July 17, 2018 | 4:13 pm

Independent study examining public safety risks of Mariner East pipelines

Community group commissions ‘quantitative risk analysis’ after county council deadlocks on proposal
By Jon Hurdle

In the distance, construction of the Mariner East 2 pipeline at Raystown Lake Recreation Area in Huntingdon County, Pennsylvania.

Mariner East 2 pipeline spill prompting underwater inspection, ‘no wake zone’ at Raystown Lake

Sunoco spilled 25-30 gallons of drilling fluid into Raystown Lake in December, and divers are now assessing impacts to the lake bottom.

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An environmental cleanup crew works to remove fuel from a spill in Darby Creek in Tinicum Township, Pennsylvania, near the Philadelphia International Airport.

Sunoco’s stand-in ME2 line leaked gasoline at Darby Creek, pipeline map indicates

Mapping data and Sunoco’s statements point to a 12-inch pipeline that would allow the company to fulfill customers’ orders for natural gas liquids while construction of the long-delayed Mariner East 2 pipeline is being completed.

By Jon Hurdle

In the distance, construction of the Mariner East 2 pipeline at Raystown Lake Recreation Area in Huntingdon County, Pennsylvania.
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