Sunoco Logistics Partners LP is considering constructing a third pipeline to deliver Appalachian natural gas liquids (NGL) to its Marcus Hook Industrial Complex on the Delaware River south of Philadelphia, a company spokesman confirmed Thursday.

If the company goes forward with another pipeline, it would likely follow the 300-mile path of the company’s existing Mariner East 1, which runs from western Pennsylvania to Marcus Hook and could be built at about the same time as Mariner East 2, said spokesman Jeff Shields. He added, however, that the company does not have many details to share because there are currently no plans for an open season or construction.

Sunoco has already extended Mariner East 1, a former oil pipeline, by 50 miles between Delmont, PA, and Houston, PA. Propane deliveries began on the line in December, and the company is ramping up for both propane and ethane deliveries to start by the third quarter.  Plans for Mariner East 2 call for constructing 350 miles of pipeline along the same path to transport ethane, butane and propane from processing and fractionation complexes in eastern Ohio, western Pennsylvania and West Virginia to Marcus Hook — a former oil refinery that’s being repurposed for NGL storage, processing and distribution to local, domestic and international markets (see Shale Daily, Dec. 5, 2013).

A successful open season for Mariner East 2 was completed last November (see Daily GPI, Nov. 6, 2014). Shields said the company is working along the pipeline’s proposed path to secure easements and permits. Construction is expected to begin in 2016, he said, and NGL deliveries should begin by the end of the year. Those two projects combined have a capacity of 345,000 b/d and represent a $3 billion investment.

Shields said that although it depends on business interest, a third Mariner East pipeline could have up to 225,000 b/d of capacity. If Mariner East 2 is eventually expanded, the new pipelines would provide 675,000 b/d of additional NGL capacity to Marcus Hook, Shields.

Sunoco’s consideration of another pipeline is representative of the anticipated demand for Appalachian NGLs, but landowners along the Mariner East route have also said they would rather have a third pipeline built at the same time as the second to reduce the impacts of long-term development.