The grand jury came to light after Phil Heron, editor of the Delaware County Daily Times, was called in for jury duty last week, where he discovered it was to be a grand jury investigating Mariner East, Sunoco and parent company Energy Transfer Partners.
Heron said Chester County Judge Jeff Sommer outlined how a grand jury worked.
"All of a sudden he starts talking about the Mariner East Pipeline, and I almost fell out of my chair," Heron recalled. "That's when it really clicked — and this goes back a few weeks ago when Chester County District Attorney Tom Hogan announced that he was, in fact, launching a criminal investigation into Mariner East."
Heron was rejected for the panel.
Sam Bernhardt, the Pennsylvania advocate for Food and Water Watch, said it appears the Chester County district attorney is serious about seeing an investigation through on the pipeline and numerous safety and health questions that have been raised surrounding the project.
"This grand jury, one can surmise, would be working toward affirming indictments into this situation," he added.
He said prosecutors only impanel grand juries when they have investigations that show potential for serious wrongdoing.
A number of lawsuits have already been filed against Sunoco and Energy Transfer over the risks of the pipeline. Construction has been stopped across the state while legal action moves forward, along with investigations at the state level.
Energy Transfer did not respond to an email for comment.