The Federal Bureau of Investigation (FBI) is said to be investigating how Pennsylvania Gov. Tom Wolf’s administration issued permits to construct the controversial Mariner East (ME) pipeline system, according to news media reports.

The Associated Press first reported on the investigation Tuesday, citing three anonymous sources. The FBI is reportedly examining whether the administration forced the state Department of Environmental Protection (DEP) to approve permits for the project despite possible shortcomings in the applications.

News of the probe comes after district attorneys (DA) in Chester and Delaware counties launched separate criminal investigations into the project, which is owned by Energy Transfer LP and operated by Sunoco Pipeline LP. The Delaware County DA is also receiving assistance from Pennsylvania Attorney General Josh Shapiro.

The ME system, which consists of three pipelines in various stages of development and service, has faced constant regulatory and legal challenges that have led to delays and operational problems. Sinkholes have repeatedly opened up along the right-of-way, at times stopping service on ME 1, while construction problems on the broader system have fouled water in populated areas, stoking public outrage.

Most project opposition has come from southeast Pennsylvania, including Chester and Delaware counties, where the project’s issues have primarily been and where shale development does not occur.

Energy Transfer spokesperson Lisa Coleman told NGI’s Shale Daily that “we are not aware of any investigation,” adding that the company has not been contacted by the FBI, which has neither confirmed nor denied the probe, according to reports. 

The ME system started operations in 2014 after ME 1, a former refined products line that was converted to move natural gas liquids, entered service. Sunoco launched an open season for ME 2 in 2013, which was initially slated for in-service in late 2016. But the timeline was pushed back in order to obtain all necessary permits, which didn’t occur until 2017. 

Prior to receipt of the key permits, DEP said because of the complexity of the project, it would enhance and extend public participation in the permitting process. Part of the regulatory review included revisions to the original permit applications submitted by Sunoco. The agency did notify the company of technical deficiencies in its applications, which were eventually resolved. DEP issued all key water and erosion permits in February 2017, clearing the way for construction to start.

But the project has been plagued since then. ME 2 has yet to enter full service, while a third pipeline, ME 2X, isn’t expected to come online until next year. The DEP has issued dozens of violations and fined the project more than $13 million as a result.

Project opponents welcomed news of the investigation.

“From the very beginning and many times along the way, we have raised serious questions about the permitting process of the Mariner East project,” said state Sen. Andrew Dinniman (D-Chester County), who has battled the pipeline system. “I hope that this development sheds a bright light on those questions and more.”

The Clean Air Council, which challenged the state’s permits for ME 2, but later dropped the appeal in favor of a settlement with state regulators, said Tuesday it has cautioned “from the beginning that these permits were being rushed and the consequences have been disastrous.”