Energy Transfer Partners, L.P. (NYSE: ETP) is a master limited partnership that owns and operates one of the largest and most diversified portfolios of energy assets in the United States. On April 28, 2017, Energy Transfer Partners (ETP) and Sunoco Logistics Partners (SXL) closed on their previously announced merger. For more details on the ETP and SXL merger, please click (here).

Strategically positioned in all of the major U.S. production basins, ETP owns and operates a geographically diverse portfolio of complementary natural gas midstream, intrastate and interstate transportation and storage assets; crude oil, natural gas liquids (NGL) and refined product transportation and terminalling assets; NGL fractionation; and various acquisition and marketing assets.

Project Description

Our Mariner East project transports NGLs from the Marcellus and Utica Shales areas in Western Pennsylvania, West Virginia and Eastern Ohio to destinations in Pennsylvania, including our Marcus Hook Industrial Complex on the Delaware River, where they are processed, stored and distributed to local, domestic and waterborne markets.


The first phase of the project, referred to as Mariner East 1, consisted of interstate and intrastate propane and ethane service and commenced operations in the fourth quarter of 2014 and the first quarter of 2016, respectively. The second phase of the project, referred to as Mariner East 2, will expand the total takeaway capacity to 345 thousand barrels per day for interstate and intrastate propane, ethane and butane service. Sunoco Pipeline has begun construction of Mariner East 2 across Pennsylvania, West Virginia and Ohio. The 20-inch pipeline is scheduled to be in service by the end of 2018. The 16-inch pipeline is scheduled to be finished in 2019.

End Markets

The Mariner East projects are designed to provide needed pipeline infrastructure to transport ethane, propane, and other petroleum products from the Marcellus Shale to markets in Pennsylvania and elsewhere. Additionally, the Mariner projects will play a major contributing role in repurposing of the Marcus Hook Industrial Complex as the Northeast hub for distribution of natural gas liquids to commercial markets domestically and globally.

Economic Impact

To date, Mariner East Phase I has created jobs and economic development opportunities throughout Pennsylvania, and the potential for additional job creation and economic development via Mariner East Phase II will be recognized in Ohio, West Virginia, Pennsylvania and Delaware. Read more about the economic impact of the Mariner East projects.