Sunoco Pipeline has obtained approval for Pennsylvania service via a pipeline placed into service in 1936. Repair and replacement work on that Mariner East 1 pipeline is ongoing. Sunoco pipeline has also obtained federal approval to construct an interstate Mariner East 2 pipeline to transport propane and ethane. Sunoco Pipeline has not obtained eminent domain power for this pipeline, although the company regularly asserts that is has that power via state law. The state of Pennsylvania has no jurisdiction, or power, to provide eminent domain power for the interstate pipeline known as Mariner East 2. Sunoco has now disclosed a plan for a third pipeline, as discussed below.

Mariner East 2 (+1): Sunoco eyes second Pa pipeline

Written by: Nick Malawskey |

Photo above: Sunoco Logistics’ Mechanicsburg facility, where work is currently underway related to the Mariner East I pipeline. (Nick Malawskey,

Sunoco Logistics said Thursday it is considering doubling-down on its Mariner East II project, potentially adding a second pipeline as part of the overall project.

The Philadelphia-based company said it is still acquiring right-of-way for the Mariner East II project, which it is expecting to go live by the end of next year. On Thursday company spokesman Jeffrey Shields said that based on interest in the project, Sunoco is now considering building two parallel lines as part of Mariner East II.

The 350-mile long pipeline will run from Ohio to Marcus Hook near Philadelphia, and will transport natural gas liquids for local and international markets.

It will roughly parallel the company’s existing Mariner East pipeline, which has been retrofitted to carry propane from western Pennsylvania to Marcus Hook. Mariner East formerly carried oil and oil-related projects from the coast west.

Shields said whether or not the company doubles-down on Mariner East II will largely depend on how successfully the company can sell capacity. If there is enough interest, Sunoco could hold an “open season” – in which gas providers contract for capacity, later this year.

“It’s not a done deal, we’re still gaging the interest,” he said.

Building both pipelines at the same time, Shields said, would limit construction impacts on local landowners and communities.

Earlier this year Sunoco Logistics withdrew its petition to the Pennsylvania Public Utilities Commission to be exempted from local zoning rules along the pipeline route. The company can still use eminent domain to build the pipeline, but will have to comply with local rules when building pump stations or other structures.

When completed, Mariner East 2 could carry between 250,000 and 675,000 barrels per day across the state.