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PUC Clarifies Mariner East 1 ‘Remaining Life’ Settlement and Public Reporting

The Pennsylvania Public Utility Commission last week clarified sections of a March tentative order that requires Sunoco to conduct a “remaining life study” of its aging Mariner East 1 natural gas liquids pipeline.


The settlement, which also includes a $200,000 Sunoco penalty, came after an investigation into a 2017 leak in eastern Pennsylvania of about 840 gallons of ethane and propane.

Sunoco and the PUC Bureau of Investigation and Enforcement (I&E) had 10 days after the tentative order was issued to file comments on areas of concern. As a result of those comments, several clarifications to the March order were made as part of the PUC’s Second Tentative Order and Opinion.


The original order provides for an independent expert to undertake a study of the Mariner East 1’s remaining life, provide a schedule of replacement and repair work over the next five years, and conduct monitoring. The independent expert is to be chosen by the PUC from three candidates submitted by Sunoco.


The pipeline was built in the 1930s and was originally used to transport fuel and heating oil to Western Pennsylvania. Sunoco purchased the pipeline, and in 2014 converted it to carry NGLs from the Marcellus and Utica plays in Western Pennsylvania to Marcus Hook.

Sunoco is also building two additional pipelines, Mariner East 2, along the same path to carry gas products to the market. The project has been fraught with construction problems and environmental violations and drawn opposition from many residents along the path in eastern Pennsylvania. The company has paid more than $13 million in penalties.


The latest order clarifies that the independent expert may communicate with both the PUC and Sunoco while it is performing the study “for the purpose of verifying underlying factual data or methods of analysis to ensure accuracy in the study. We expressly note that all communication between the independent expert, I&E, and Sunoco should be conducted jointly, in the interest of preserving transparency and objectivity of the independent expert’s final form study and public summary,” the latest order states.


It also sets out the procedure for the submission of the final study and the public summary. Sunoco argued that it should first be given access to the final report and public summary to make sure that it does not contain any confidential proprietary or security information. The administrative law judge disagreed.


“We do not agree with Sunoco’s suggestion that the only means to protect Sunoco’s (confidential security information) from public disclosure is by granting Sunoco the right to review the independent expert’s final form study and public summary of the study and that Sunoco should control their submission to I&E and the Commission. To do so would unnecessarily call into question the independence and objectivity” of the report.


The judge said that since the final report will not be made public, confidentiality is less of a concern. However, the judge determined that the public summary should be provided to both the PUC and Sunoco before release, giving the parties 10 days to raise confidentiality claims before it is released.


The latest order also provides a 10-day window for comments by interested parties and a period during which they may consider withdrawing. If there are no comments, the order requiring the remaining life study will be final.

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