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Press Release

Update Regarding PUC Investigation Involving Mariner East 1 Pipeline

Published on 1/21/2019

Filed under: Gas

HARRISBURG – The Pennsylvania Public Utility Commission’s (PUC’s) independent Bureau of Investigation and Enforcement (I&E) – which includes the PUC’s Pipeline Safety Division – issued the following update today regarding the active and ongoing safety investigation regarding the Mariner East 1 (ME1) pipeline:

On January 20, 2019, at approximately 4:40 p.m., the PUC’s Pipeline Safety Division was notified by Sunoco Pipeline LP, a/k/a Energy Transfer Partners (SPLP), that a new subsidence feature had formed near Lisa Drive, in Chester County, exposing the ME1 pipeline.

I&E immediately dispatched a safety engineer to the site. I&E’s geophysical consultant, ARM, was also asked to send a representative to the site.

To ensure public safety, at approximately 6:30 pm on January 20, 2019, I&E proposed to SPLP that this section of the ME1 pipeline be shut down pending further investigation. At approximately 7:30 p.m. on January 20, 2019, SPLP initiated the stoppage of product transportation through this section of ME1. 

The shutdown was completed at approximately 12:06 a.m. on January 21, 2019. As a result of this shutdown, there is no product flowing through an approximately 7-mile long section of pipeline, between valves located at Boot and Exton, both in Chester County.

I&E has remained engaged in this matter and in constant contact with SPLP personnel since first being notified of the incident.

In order to move forward with its investigation and remediation of this recent incident, I&E has engaged in numerous discussions and has directed SPLP to take the following action:

  • SPLP has “shut down” this section of ME1, meaning no product is flowing in this portion of the line;
  • SPLP will introduce flowable fill into the subsidence feature as an immediate and temporary fix to assist in the stability of the pipeline;
  • SPLP will purge the product from the shutdown portion of ME1 and it will remain purged of product for the duration of I&E’s investigation of this incident;
  • SPLP will perform geophysical testing in the vicinity of this subsidence feature in cooperation with I&E’s safety engineers and I&E’s geophysical consultant; and,
  • SPLP will not resume the transportation of product through this section of ME1 until approval is received from I&E. 

As the independent investigation and enforcement bureau of the PUC, I&E has the authority to bring enforcement action, seek emergency orders from the Commission or take other steps to ensure public safety, should circumstances change or based on the finding of the investigation.

The Pennsylvania Public Utility Commission balances the needs of consumers and utilities; ensures safe and reliable utility service at reasonable rates; protects the public interest; educates consumers to make independent and informed utility choices; furthers economic development; and fosters new technologies and competitive markets in an environmentally sound manner.

For recent news releases and video of select Commission proceedings or more information about the PUC, visit our website at Follow the PUC on Twitter – @PA_PUC for all things utility. “Like” PA Public Utility Commission” on Facebook for easy access to information on electric shopping.

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