Another sinkhole in Chester County materialized on Sunday, leaving a 5-foot stretch of the Mariner East 1 liquids pipeline bare and prompting Sunoco to suspend transport on the line.
The Pennsylvania Public Utility Commission has sent “pipeline engineers, geologists and other experts to investigate this incident,” said PUC spokesman Nils Hagen-Frederiksen.
What they find will guide the agency’s future actions, he said.
Sunoco, a division of Texas-based Energy Transfer LP, said on its website that “there is no impact to the line” and that it is working with regulators and consultants to stabilize the area.
“It’s too early to know additional details at this time,” the company wrote on Monday.
The majority of Mariner East 1, which stretches across southern Pennsylvania, was built in the 1930s. The 8-inch diameter line was originally designed to carry gasoline to the western part of the state. It was reserved and filled with natural gas liquids when the Marcellus and Utica shales were found to have a bounty of these valuable products. The line is now used to deliver the liquids to processing facilities in the Philadelphia area and to ports for export.
This particular area of Chester County in West Whiteland Township has caused problems for residents and for the company before.
Last March, the Mariner East 1 pipeline was shut down for nearly two months after a series of sinkholes occurred on the same street as the current event. At the time, the subsidence was related to the construction of two parallel lines, the Mariner East 2 project, that were being developed in the area last year.
After inspecting the line and being satisfied that Sunoco had taken steps to stabilize the ground, regulators allowed it to restart.
Mariner East 1 was ordered shut down again later that month by an administrative law judge in response to a petition from state Sen. Andrew Dinniman, D-Chester. But the PUC returned it to service.
Anya Litvak: alitvak@post-gazette.com or 412-263-1455.
First Published: January 21, 2019, 9:26 p.m.