Construction permits issued in Pennsylvania for a controversial cross-state natural gas pipeline have been suspended by the state Department of Environmental Protection.

Under an order, employees of Sunoco Pipeline LP, a subsidiary of Energy Transfer Partners, must cease construction of the Mariner East 2 pipeline, which will stretch from beyond the state’s western border to a Delaware County processing facility.

The suspension is a result of Sunoco employees’ failure to meet certain provisions established by DEP construction permits, according to the Wednesday announcement.

“Until Sunoco can demonstrate that the permit conditions can and will be followed, DEP has no alternative but to suspend the permits,” DEP Secretary Patrick McDonnell said in a statement. “We are living up to our promise to hold this project accountable to the strong protections in the permits.”

The suspension order, submitted Wednesday and signed by DEP Acting Executive Deputy Secretary Ramez Ziadeh, alleges that work to construct the Mariner East 2 has violated rules established in both the state Clean Streams Law and Title 25 of the Pennsylvania Code.

The 300-plus-mile pipeline will pass through Blair, Cambria and Huntingdon counties.

Sites in Blair County’s Woodbury Township and Huntingdon County’s Tell Township are referenced in Wednesday’s suspension order.

The 24-page order cites a number of violations including the discharge of industrial waste into state waters without a permit and a failure by Sunoco officials to secure authorization before drilling at several sites, including in Blair County.

That failure to obtain permits “constitutes unlawful conduct,” according to the order, which cites the state Dam Safety and Encroachments Act and Clean Streams Law.

Mariner East 2 construction occasionally requires horizontal drilling to create a pathway. Workers use drilling equipment lubricated by a combination of water and bentonite clay under pressure.

Typically, that lubricant and removed materials flow out through a borehole, but at times, fractures in rocks and other geological variations allow the liquid to leak elsewhere. Those leaks are known as inadvertent returns.

Wednesday’s order stipulates that construction will not be allowed to resume until Sunoco officials meet a new set of stipulations.

Those stipulations include, among other rules, a requirement that officials must “submit a detailed operations plan outlining additional measures and controls to minimize inadvertent returns.”

In a Wednesday afternoon email, Jeff Shields, a Sunoco spokesman, responded to questions about the suspension and acknowledged that company officials had received notice of the order from DEP.

Construction will remain suspended until pipeline developers submit a number of reports “related to current and future construction activities,” Shields said.

“We intend to expeditiously submit these reports, and we are confident that we will be reauthorized to commence work on this project promptly,” Shields said. “We also reiterate our commitment to the highest levels of construction expertise and our dedication to preserving and protecting the environment in which we conduct our work.”

While construction is suspended, Sunoco employees will be permitted to work on erosion controls and “limited” maintenance of horizontal directional drilling equipment.

This is not the first time that work on the pipeline has been halted.

In July, a state environmental hearing board judge ordered that drilling had to stop at 55 locations along the pipeline route after dozens of drilling lubricant leaks, including in Blair and Huntingdon counties, were revealed by DEP.

In mid-August, it was announced that drilling would resume after a settlement was reached between Sunoco and a number of environmental groups, which challenged DEP permits related to Mariner East 2 construction.

Drilling was allowed to resume, but the settlement set up more stringent oversight and reporting guidelines for pipeline developers.

Wednesday’s order also claims that Sunoco employees have ignored the settled-upon reporting guidelines on a number of occasions.

Locally and across the state, the Mariner East 2 has faced opposition from protesters, who claim it is a risk to the environment, while others have supported the pipeline for its expected economic benefits. On Wednesday, both sides commented on the suspension order.

“Today’s order … ultimately represents DEP’s understanding that Sunoco shamelessly broke a number of terms and conditions that Delaware Riverkeeper Network and others helped secure through … a settlement agreement,” Maya van Rossum, leader of the Delaware Riverkeeper Network, said in a statement. “This order provides further evidence that the project should never have been authorized by DEP in the first place.”

In a separate statement, Kurt Knaus, a spokesman with the Pennsylvania Energy Infrastructure Alliance, continued to tout the project’s financial benefits.

“This project remains critically important for our commonwealth,” he said. “Sunoco and DEP should work expeditiously to resolve this matter so safe construction can resume and this vital project can get back on track.”

Sunoco officials can appeal the DEP suspension to the state Environmental Hearing Board, DEP spokesman Neil Shader said.

Mirror Staff Writer Sean Sauro is at 946-7535.