The firm will further assess, investigate Chester County Marsh Creek Lake spill and restore impacted resources


Sunoco will assess the rerouting of the 20-in pipeline. (Credit: PublicDomainPictures from Pixabay)

Sunoco Pipeline, a unit of Energy Transfer LP, has been ordered by the Pennsylvania Department of Environmental Protection (DEP) to reroute the planned Mariner East II natural gas liquids (NGL) pipeline in the US.

The firm has also been ordered to undertake further assessment and investigation, and restore resources affected following spilling of drilling fluid, an industrial waste, during the construction of the Mariner East II NGL pipeline in Upper Uwchlan Township, Chester County in August 2020.

The horizontal directional drilling (HDD) site, which is referred to as HDD 290, that caused the impacts comprises the installation of two pipes a 16-inch pipe and a 20-inch line.

About 8,000 gallons of drilling fluid spilled, creating deep subsidence

As a result of Sunoco’s ‘potential inadvertent return at HDD 290’, over 8,000 gallons of drilling fluid has been spilt, creating deep subsidence and adversely affecting wetlands, two tributaries to Marsh Creek Lake, and the lake itself, in Marsh Creek State.

DEP Secretary Patrick McDonnell said: “These incidents are yet another instance where Sunoco has blatantly disregarded the citizens and resources of Chester County with careless actions while installing the Mariner East II Pipeline.

“We will not stand for more of the same. An alternate route must be used. The department is holding Sunoco responsible for its unlawful actions and demanding a proper cleanup.

“To the fullest extent possible under our laws and regulations, we will continue to hold this company accountable for their actions, impacts, and behavior.”

Sunoco will assess rerouting the 20-in pipeline away from Marsh Creek Lake and also provide plans to address the impacts of the drilling fluid spill and subsidence events.

Moreover, the firm will undertake corrective actions including impact assessments and restoration as well as required remediation as a result of the spill.