News reports indicate the Pennsylvania Public Utility Commission (PUC) granted an emergency order Wednesday to stop the flow of natural gas liquids (NGLs) on Sunoco Logistics' Mariner East 1 (ME1) pipeline.

According to the reports, the PUC said Sunoco’s construction of two sister pipelines, Mariner East 2 (ME2) and 2X, were creating sinkholes in pipeline construction areas, and that keeping the ME1 pipeline active while builder Sunoco and regulators assess its integrity creates a public safety hazard.

Sunoco will be required to perform a series of tests on a two-mile portion of the line and submit the results to the PUC. The pipeline is expected to stay off-line for up to two weeks,...