The Delaware County District Attorney’s (DA) office in southeast Pennsylvania said it has opened a second criminal investigation into the construction and operation of the Mariner East (ME) 1, 2 and 2X projects.

DA Katayoun Copeland said her office had also requested and is receiving assistance from Pennsylvania Attorney General (AG) Josh Shapiro’s office. Authorities are investigating alleged criminal misconduct by Energy Transfer LP, subsidiary Sunoco Pipeline LP and the related corporate entities behind the ME project.

“There is no question that the pipeline poses certain concerns and risks to our residents, and as district attorney, I am working to do everything possible within my power to ensure the safety of residents,” Copeland said Monday in announcing the investigation.

The DA is currently reviewing evidence with the AG’s office and seeking action within the county’s jurisdiction.

“Due to the fact that the pipeline spans over 17 different counties in Pennsylvania, we sought assistance from our partners in law enforcement, the Pennsylvania’s attorney general’s office,” Copeland said. “As this remains an open and active investigation, the details available for disclosure are very limited, as is the case in any investigation.”

The announcement follows another in neighboring Chester County, where DA Tom Hogan in December launched a criminal investigation into construction of the ME system. Calling the allegations in that case “baseless,” Energy Transfer has denied wrongdoing and said it was confident that no criminal laws have been violated.

The project has repeatedly confronted legal and regulatory issues related to fouled well water, sinkholes that have formed near the right-of-way, historic fines for construction violations and leaks, many of which have occured in the southeast part of the state, where residents have demanded more action from public officials.

ME 1, an old refined products pipeline built in the 1930s, was converted in 2013 to move 70,000 b/d of ethane and propane. It remains offline after a sinkhole formed near it in January. Partial service started on ME 2 in 2018 after roughly two years of delays using another older refined products pipeline to bypass areas where construction remains on hold due to regulatory issues. ME 2X also remains under construction.

ME 2 and 2X would run parallel for about 350 miles alongside part of ME 1 to move ethane, butane and propane from processing facilities in Ohio, Pennsylvania and West Virginia to the Marcus Hook Industrial Complex near Philadelphia.