Marsh Creek State Park once again the site of cleanup due to Mariner East pipeline construction

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Workers for Mariner East pipeline builder Energy Transfer are back at the area in and around Marsh Creek State Park to contain a new leak of what appears to be bentonite clay, a material used in horizontal drilling as part of the underground pipe laying process. A resident reported seeing the whitish material in a tributary of Marsh Creek on Feb. 15, two years after the company completed construction of the 350-mile-long cross-state natural gas liquids pipelines, and three-and-a-half years after construction at the same site caused between 21,000 and 28,000 gallons of drilling mud to enter Marsh Creek Lake.

Energy Transfer paid more than $4 million dollars in penalties for the August 2020 incident. While the company cleaned it up from the lake and surrounding wetlands, some of the clay likely seeped below the surface into the soil or underground aquifer. Pipeline construction in that area of Chester County wreaked havoc throughout the project, causing sinkholes and polluting wetlands through “inadvertent returns” of drilling mud as the company bored through karst, or limestone, a porous and unstable rock.

A Pennsylvania Department of Environmental Protection employee wrote in an inspection report on Feb. 16 that they saw the material flowing out of a wetland at the site of a previous sinkhole, the very same location of the August 2020 incident.

“It is possible that the remaining bentonite in the soil column at this previous inadvertent return location has been pushed to the surface by the rising water table,” wrote the inspector. The substance is currently being tested.

Photos attached to the report show a small stream and wetland clogged with a muddy clay-like substance. Samples were collected and sent out for testing.

Nearby resident Chris “P.K.” DiGiulio, who has documented the construction through photos and drone footage, followed the tributary up to the wetland near private property and said she saw a “whitish, somewhat slimy clay-like substance.”

“We tracked it up until we found where it stopped and it looked like a mud pot, to be honest,” said DiGiulio. “It was all over the place, and [there was] a sign saying that it’s a protected wetland.”

DiGiulio says she’s worried about the impact on her own well water, the overall health of the ecosystem and safety.

While bentonite clay is not poisonous, it can smother the tiny macroinvertebrates that feed larger fish and aquatic life.

“We’re coming up on spring and all the little critters, the macroinvertebrates, the things that are so essential to the health of an exceptional value wetland, for example, are being impacted and suffocated because that’s exactly what bentonite does,” she said.

DiGiulio said she wants to know more about the geological stability of that area. Energy Transfer remediated the area by pouring grout or cement into the sinkholes.

“There are two active, highly volatile hazardous liquid pipelines that are in that area and it was considered stable because of the grouting,” she said. “But [the clay is] escaping again and I’d like to know that it’s safe for the residents and for my community.”

If a pipeline becomes unstable it could crack, leading to a leak and a potential explosion.

The Mariner East project consists of three pipelines carrying highly volatile ethane, propane, and butane: the 8-inch Mariner East 1 line; the 20-inch Mariner East 2 line; and the 16-inch Mariner East 2x. The lines carry Marcellus Shale gas from western Pennsylvania to the Energy Transfer’s  800-acre terminal in Marcus Hook, Delaware County, where the bulk of the product is shipped to Scotland to make plastics.

The project, completed in 2022, took five years to construct. Two years behind schedule, the last section was delayed because of the 2020 spill into Marsh Creek Lake. The Attorney General’s Office, led at the time by current Gov. Josh Shapiro, filed 48 criminal charges against the Texas-based company. The DEP has issued more than 120 notices of violations to Energy Transfer, which has paid more than $20 million in fines and assessments since construction began in February 2017. The state Public Utility Commission temporarily shut down the operation of the Mariner East 1 pipeline in 2018 over safety concerns.

Construction mishaps and resulting safety issues regarding the pipeline led the PUC to revise existing rules for the state’s hazardous liquid pipelines, with the final rules published on Thursday. The PUC’s new rules would change requirements for annual reports, accident reporting, notification of new construction and conversion, spacing, analysis of horizontal directional drilling, identification of nearby water supplies and notification to owners, coordination with emergency responders and schools, public education, corrosion requirements and standards for land agents who seek right-of-way from landowners.

Energy Transfer says none of the substance entered Marsh Creek Lake and it is working with DEP on restoring the area. The Department of Environmental Protection said the release of the material has halted, and the agency continues to investigate the cause.

Updated with a response from DEP.