Sunoco To Shut Down Work At Sinkhole Near Exton Library

WEST WHITELAND TOWNSHIP, PA — Multiple sinkholes that have developed around the Valley Creek Sunoco drilling site near Chester County Library Exton over the summer have shut down operations there, after an action from the Department of Environmental Protection.

The PA DEP said, "Due to multiple unanticipated impacts at the Valley Creek/Wetland B-71 bore site in West Whiteland Township, DEP has asked, and Sunoco has agreed, to voluntarily shut down operations at the site."

The "multiple unanticipated impacts" at Wetland B-71 started up on June 3 when turbid water from Sunoco's groundwater treatment system for the drilling bore there was being discharged into Ship Road Run — a tributary to Valley Creek near the Chester County Library, Exton.

After residents alerted the Pennsylvania Department of Environmental Protection of the situation and the sediment discharges, a Notice of Violation was issued citing Sunoco for discharging water with excessive "suspended solids" in it.

Resident group West Whiteland Residents for Pipeline Safety on June 3 posted a video of sediment-laden water pouring from the worksite into the wetland that leads to Valley Creek. The video can be viewed here.

DEP said it has asked Sunoco to halt operations and prepare a plan that will outline the steps that will be taken to mitigate or prevent future subsidences at this drill location. "Subsistences" refers to sinkholes.

"Dewatering operations issued under a separate DEP authorization will continue," the DEP said Tuesday.

"Sunoco will submit a plan that discusses the previous grouting operations which were conducted to address the recent subsidences, and also outline the required restoration for those sites and submit a plan to prevent future subsidences from occurring on-site during the completion of the pipeline installation," DEP Press Secretary Jamar Thrasher said.

Seven sinkholes along Sunoco's drilling sites have been reported over the last year, and DEP said two of those occurred at least partially in wetlands. Another sinkhole formed after a spill by Sunoco of drilling fluid into Marsh Creek Lake wetlands in August 2020.

"DEP has been in coordination with PUC, which regulates pipeline safety issues, and has responded to these events accordingly," Thrasher said.

But DEP anticipates the work will continue. Sunoco is currently 244 feet into a 370-foot bore at the Wetland B-71 site, Thrasher explained. He said the remaining work to be done will involve crossing Valley Creek. "DEP will continue to work with Sunoco to ensure that permit conditions are met and the environment is protected," he added.

An on-site field meeting with DEP, Sunoco, and PUC is scheduled to take place early next week to discuss the activities that are being proposed, according to Thrasher.

The Pennsylvania Public Utility Commission this week also received a letter from Chester County Commissioners on Monday requesting that two Mariner East pipelines be ordered to cease operations while further investigations examine the impact on public safety from a recent outbreak of construction-induced sinkholes near the lines.

With at least seven sinkhole formations documented this year, the Commissioners urged PUC to take swift action to protect residents' safety.

Read a recent related story here.

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