Going above and beyond


The safe operation of all our assets, including our Mariner East pipeline system, is our first priority. We strive for excellence and apply the highest standards when constructing and operating our energy infrastructure. We recognize the responsibility that comes from moving energy safely and are proud of the role we play in Americans’ daily lives. In Pennsylvania, we own and operate more than 3,000 miles of pipeline, two major storage facilities and many other related assets. We believe no other company in any industry has invested the amount of capital in Pennsylvania that we have.

Building and operating new energy infrastructure is a complex topic — that’s why we set our standards high and often exceed the strict federal rules for pipeline safety. Safety — the safety of our people, the safety of our communities and the safety of the environment — is our highest priority.

At Energy Transfer, we pledge to the communities we cross and the customers we serve that we will operate our pipeline with the highest level of safety at all times. The Mariner East pipeline system is built and operated in accordance with all state and federal laws, rules and regulations, while employing the industry’s best practices and advanced technology to protect Pennsylvania’s valuable lands.

Safety Across the Board

A report on the Mariner East pipeline system from pipeline safety consultant Accufacts found that Energy Transfer has incorporated safety processes in excess of minimum federal regulations in several areas

Integrity Testing

Pipe Welding

Pump Station Design

Pipeline Monitoring

Release Detection

Emergency Notification

  • It starts in the pipe mill, where inspectors oversee the manufacture of the pipe to strict standards. The pipe is inspected again when it arrives on the construction site.
  • Before and after the pipeline is buried, and ongoing once it is in operation, we put our pipelines through rigorous testing above and beyond what is required by federal safety regulations. Then we monitor them 24/7, 365 days a year, from our central monitoring facility.
  • We employ heavier pipe-wall thickness than required by the U.S. Department of Transportation. The higher quality of pipe reduces the risk of damage from sources such as excavating equipment and ground movement.
  • We bury the pipeline deeper underground than required in most cases — at least 4 feet and up to 200 feet.
  • We inspect 100% of the pipeline’s mainline girth welds by X-ray, rather than the 10% required.
  • We patrol our Mariner East pipelines — by ground and air — more frequently than required.
  • We team with local emergency responders along the route to provide information and training on emergency pipeline response. Since 2014, we have trained more than 2,000 emergency responders and public officials.
  • State and federal regulators spent more than 100 inspection days during 2017 on the Mariner East project, which are more inspection days than on any other pipeline in Pennsylvania.
  • In some locations, we have elected to install casing in order to minimize the potential for adverse environmental impacts during construction in this area. After discussions with the Pennsylvania Public Utility Commission (PUC) about ways to proactively mitigate the potential for subsidence and inadvertent returns, we determined that installing casing was the appropriate measure in certain geologies. State and federal regulators understand that casing installation is an industry best practice option. These proactive safety measures are to the benefit of the surrounding environment and communities.


Energy Transfer monitors more than 85,000 miles of pipeline via a computerized supervisory control and data acquisition (SCADA) system on an around-the-clock basis, 365 days of the year, from our control centers. Our centers are staffed by highly trained pipeline controllers who have qualified as operators as required by the U.S. Department of Transportation.

The SCADA system tracks pressure, flow, temperature and other operating data via a series of field instruments to ensure that all operations are normal. Our pipeline controllers maintain communications with field and terminal operations so that all involved employees are kept abreast of current and future pipeline operations.


  • High-tensile-strength steel.
  • Protective coating.
  • Pressure-tested at the mill.
  • Pipe design regulations require additional safety factor in higher risk areas such as road crossings, river crossings and high population areas.
  • All welds 100% X-rayed or NDE inspected.
  • Pressure-tested at a minimum of 125% of maximum operating pressure.

In-Line Inspection Tools

  • Various tool technologies that may be used to identify and measure metal loss from corrosion and gouges, identify dents and other deformations, and detect longitudinal cracks and crack-like defects.

Warning Signs

  • Pipeline markers and warning signs indicate approximate location of the pipeline.
  • Located at frequent intervals along the pipeline right-of-way.
  • List product, name of the pipeline operator and operator’s telephone number in case of an emergency.
  • Display 811 “Call Before You Dig” notification phone number.


  • Chain-link security fencing.
  • Security camera and monitoring.


  • Both automated and manual valves are strategically placed along the pipeline.
  • Can be used to stop flow along a certain section of pipe.
  • Inspected periodically in accordance with regulations.
  • A variety of valves are used both above and below ground.

Cathodic Protection

  • Inhibits corrosion by application of electrical current with anode bed.
  • Effective protection requires very low DC voltage.
  • Entire pipeline is protected below ground Inspected and tested annually, rectifier inspected every other month.
  • Test stations approximately 1 mile apart.

Aerial Patrol

  • Visual inspection along the right-of-way for: pipeline leaks (dead vegetation, discoloration, etc.), sunken backfill, exposed pipe, land erosion and unauthorized excavation.

Ground Patrol

  • Visual inspections and surveillance of the pipeline along the right-of-way.
  • Maintenance and inspections of equipment and valves.

Supervisory Control and Data Acquisition (SCADA) Systems

  • Control system that uses computers and networked data.
  • Sends critical information to pipeline operations teams.
  • Automates data logging and processing.

Control Center

  • Centralized control center to immediately and easily adjust flow rates in the pipeline.
  • Pipeline engineers know exactly what is happening along the pipeline at all times.
  • Can quickly react to equipment malfunctions, leaks or any other unusual activity along the pipeline.