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Marsh Creek Lake – (HDD 290)

This page was last updated on April 7, 2022

Marsh Creek Lake, located in Chester County, is approximately 535 acres and located in Marsh Creek State Park. As it relates to Sunoco’s Mariner East 2 project, this location is often referred to as HDD 290.

On August 10, 2020, Sunoco spilled approximately 8,000 gallons of drilling fluid that impacted a wetland, two tributaries, and Marsh Creek Lake. On August 11, 2020, Sunoco experienced a subsidence at this same location. These two incidents resulted in the Pennsylvania Department of Environmental Protection (DEP), as well as other state and local agencies who responded to the incident, taking compliance and enforcement actions, and requiring Sunoco to mitigate, remediate, and restore the area.

This webpage has been created to collect and share the associated documents, reports, and submissions regarding this site. It will continue to be updated as new documents are submitted to DEP for review.

Spring 2022 Update – Major Amendment Approval
On January 19, 2022, Sunoco submitted a major amendment application for its Ch. 102 (Erosion and Sediment Control) permit as required under the terms of the Consent Order and Agreement (COA) entered into between the DEP, DCNR, and Sunoco dated December 6, 2021. As outlined in the COA, Sunoco is required to dredge portions of the lake to remove drilling mud and sediment present as a result of the spill. This major amendment was requested to support the dewatering of sediment dredged from Marsh Creek Lake. Sunoco requested a 4.06 acre increase to the limit of disturbance to conduct these activities. Upon completion of the project, all areas will be restored.

DEP reviewed the submission and determined that the applications contained all necessary information to meet the requirements of DEP’s regulations and was therefore approved on April 7, 2022.

DEP additionally issued Sunoco a Temporary Discharge Authorization associated with the dredging and dewatering activities which will allow Sunoco to return water to the lake after it has been dredged and processed.

Permit documents can be found in the “DEP Issued Permits and Approvals” section below.

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Currently Under Review

There is nothing currently under review for this site.

DEP Issued Permits and Approvals

Compliance and Enforcement

Remediation, Assessment, and Restoration



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