Mariner East 2
HDD 620 Middletown Township, Delaware 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 20-inch pipeline and portions of the 16-inch pipeline in the Glen Riddle section of Middletown Township, Delaware County.
The company will switch from a horizontal directional drill (HDD) to a combination of direct pipe, conventional bore and open cut installation methods on a section of the route spanning 3,500 feet in the area of Glen Riddle Road in Middletown Township. See below for a map of the route as well as diagrams and descriptions of the construction methods..
The modification includes the following components:
- Conventional bore under Glen Riddle Road, near the intersection of Glen Riddle Road and Pennell Road
- Direct pipe bore under Riddlewood Drive, between Pennell Road and War Trophy Lane
- Direct pipe bore under the SEPTA railroad track that runs between and parallel to Riddlewood Drive and Glen Riddle Road
- Open cut installation limited to portions of the parking lots at Tunbridge Apartments and Glen Riddle Station Apartments adjacent to Glen Riddle Road, as well as section tie-ins
The modification in construction method will minimize the potential for inadvertent returns of water and clay drilling fluid or other effects and 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.
NOTE: Construction methods, completion times and exact locations are subject to change due to the inherent fluidity of the construction process and outside factors.
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.
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.
Direct pipe installation is a combination of HDD and tunneling for all soil conditions. A thruster and a steerable microtunneling machine install steel pipes in one continuous pass. The direct pipe bore method uses significantly less bentonite than other trenchless methods, dramatically reducing the possibility of inadvertent fluid returns.