Mariner East Pipeline Safety - PA | Energy Transfer

Going above and beyond


Project uses industry best practices, advanced technology to ensure safety

The safe operation of all our assets in the state is our first priority, including our Mariner East system. 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. Learn more about our Mariner East Pipeline System in the Lisa Drive Area.

Building 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 is our priority — the safety of our people, the safety of our communities and the safety of the environment.

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 2 expansion project from pipeline safety consultant Accufacts found that Energy Transfer has Incorporated safety processes in excess of minimum federal regulations in several areas:

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Integrity Testing

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Pipe Welding

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Pump Station Design

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Pipeline Monitoring

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Release Detection

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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.
  • We inspect 100 percent of the pipeline’s mainline girth welds by X-ray, rather than the 10 percent 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, more inspection days than on any other pipeline in Pennsylvania.


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

There are 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 one 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