Mariner East 2
Project Modification
HDD 280 Upper Uwchlan Township, Chester County

Sunoco Pipeline, a subsidiary of Energy Transfer, received approval from the Pennsylvania Department of Environmental Protection to change the installation method for a portion of the 16- and 20-inch pipelines located at the Pennsylvania Turnpike in Upper Uwchlan Township, Chester County.

The company will change from a horizontal directional drill (HDD) to a combination of an open cut and conventional bore on a section of the route spanning approximately 3,450 feet, mainly underneath or parallel to Meadow Creek Lane in Upper Uwchlan Township. See below for a map of the route.

The change includes the following components:

  • Conventional bore underneath Styer Road
  • Open cut installation to the north and east of the Pennsylvania Turnpike, underneath or parallel to Meadow Creek Lane in Upper Uwchlan Township

The change in construction method will shorten the time that construction is inconveniencing the local community to an estimated four months — excluding site preparation and restoration — versus the general estimated time frame of more than one year for HDD installation. The new plan directs the work further away from Marsh Creek and minimizes the potential for inadvertent returns of the water and clay drilling fluid.

NOTE: Construction methods, completion times and exact locations are subject to change due to the inherent fluidity of the construction process and outside factors.


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Our goal is safe, time-efficient pipeline installation

The approved change to the construction method caters to the local geology, maximizing safety and efficiency for the installation of the Mariner East 2 and 2X pipelines. The end result is the completion of active construction in a fraction of the original time frame. By using the most advanced safety technology and monitoring systems, as well as teams of experienced contractors, construction can be performed safely with less disruption to your community.

In order to proceed with the new construction methods — which will maximize safety and efficiency — the Pennsylvania Department of Environmental Protection (DEP) approved major modifications to the existing permits.

What Is a Major Modification?

This is classified as “major modifications,” which is a change to an existing environmental permit issued for pipeline construction that exceeds a minor revision. It could be a change in the construction method, the specific pipeline route or the workspace within the right-of-way. In the case of Mariner East 2, such environmental permits are issued by the Pennsylvania DEP.

Installation Methods

The requested major modifications will be a change from Horizontal Directional Drill (HDD) to a combination of open cut, conventional bore and/or direct pipe installation methods.

Open cut installation is a straightforward and traditional method, where workspace is available. Open cut is commonly used for construction, repair and replacement of various utilities, such as pipelines and sewer and water lines. The pipeline is lowered into a dug trench, followed by backfilling of the subsoil and separated subsoil, where applicable.

Conventional bore installation involves minimal surface disturbance for long-distance installation. A boring machine at the bottom of the bore pit tunnels forward through a bore tube. The pipeline is installed through the bored hole and welded to the adjacent pipeline.

For additional information, please check out our fact sheet