Chester County residents will have an opportunity to comment on proposed changes to the process being used to build the Mariner East pipeline, the Pennsylvania Department of Environmental Protection (DEP) announced Friday. A virtual hearing is set for June 16.

“The Pennsylvania Department of Environmental Protection (DEP) announced today it will receive public comments and host a virtual public hearing regarding major permit amendment requests from Sunoco Pipeline LP (SPLP) for work near Marsh Creek Lake, Upper Uwchlan Township, Chester County,” the DEP said in a statement.

“DEP remains committed to fulfilling its responsibility to provide opportunities for the public to engage in these important permitting decisions, whether through written remarks or delivered orally at a virtual hearing,” said DEP Southeast Regional Director Pat Patterson. “We have taken several steps to ensure the public has access to this process, from making documents available online to having multiple avenues to provide testimony.”

Energy Transfer/Sunoco submitted a request for “major modification” to the DEP in April, changing its method of construction from horizontal directional drilling (HDD) to open cut, along with a shift in the pipeline route. These modifications, once implemented, will likely be the last major change in the nearly-completed, $5 billion pipeline project.

“The proposed change to the Mariner East 2 pipeline installation method adapts to the local geology and maximizes public and environmental safety,” according to a statement on the Mariner 2 East pipeline webpage. “This change would eliminate the potential for inadvertent returns of water and clay drilling fluid. Once work begins, installation will take approximately 5 to 10 weeks.

“This is one of the last sections of the 20-inch Mariner East 2 pipeline to complete in Chester County; the 16-inch Mariner East 2X pipeline has already been installed in this area,” the company stated.

Because the remainder of the project involves trench digging rather than boring beneath the ground, the proposed new path would shift the pipeline away from the front of some homes in Upper Uwchlan Township. It will also mean temporarily damming three streams that feed Marsh Creek Lake rather than drilling beneath them.

The HDD process is less disruptive to the environment, according to experts like Samuel Ariaratnam, an engineering professor at Arizona State University, who has compared the underground drilling process to angioplasty. However, it creates other potential problems, such as leaks of drilling mud known as “inadvertent returns.” Switching to the open trench method will largely take those concerns off the table for the remainder of the project.

It won’t, however, take the pipeline out of the crosshairs of opponents who’ve attempted to block it in the name of the debate over fossil fuels and climate change.

They are expected to turn out in full force for the public comment process.

“Opponents most likely will use this opportunity to call for shutting down the entire Mariner East network, a legally permitted project, just as they always do,” said Kurt Knaus, spokesman for the Pennsylvania Energy Infrastructure Alliance (PEIA). “But that’s not what this comment period is about. This is about ensuring construction is done in a safe, environmentally responsible manner, with minimal disruption to the community, so that work along this small section of line can finally finish and our commonwealth can finally realize the full benefits of this important infrastructure project.”

The pipeline company recently entered a consent decree with the Chester County D.A.’s office that resolved previous disputes and allowed construction to proceed.

‘We are not stopping the pipeline, nor do we want to,” Seth Weber, a special prosecutor with the Chester County District Attorney’s Office, told Delaware Valley Journal.

In a recent earnings call, ET said it expects the next significant phase of the Mariner East projects to be in service in the second quarter of 2021, with the final phase of the pipeline completed in the third quarter of this year.