A new federal pipeline safety order issued after a September oil spill in Michigan is raising fresh questions about the integrity of the Twin Oaks petroleum pipeline, which runs through Hopewell Township, more than a year and a half after a leak in Pennsylvania contaminated drinking water wells and surrounding soil.
The Sept. 21 order from the Pipeline and Hazardous Materials Safety Administration (PHMSA) identifies similarities between failures involving repair sleeves on the two pipelines and raises concerns that comparable problems could exist elsewhere across Energy Transfer’s pipeline network.
Built in 1958, the Twin Oaks pipeline carries gasoline, diesel and jet fuel along a 105.5-mile route from Aston, Pennsylvania, to Newark, New Jersey. After crossing the Delaware River near Jacobs Creek, the 14-inch pipeline passes through Hopewell Township near Capital Health Medical Center, Route 31 and Denow Road, continuing through established neighborhoods and the site of the Venue at Hopewell development along Nursery and Scotch roads.
Federal regulators are requiring Energy Transfer to inventory and evaluate repair sleeves throughout its hazardous-liquid pipeline system, including Twin Oaks, and develop plans to address potential problems.
The findings have prompted Delaware Riverkeeper Network to renew its call for Twin Oaks to be shut down pending further investigation, while pressing New Jersey environmental officials for answers about inspections, potential environmental risks and oversight.
PHMSA has not ordered Twin Oaks shut down, and the September order does not identify a new leak in New Jersey.
Two failures, broader concerns
The latest federal action stems from a Sept. 18 failure along Energy Transfer’s Marysville-Toledo Crude pipeline in Sterling Heights, Michigan, where crude oil escaped from a section of pipe repaired with a steel sleeve. Federal investigators found holes in a weld on the sleeve, installed in 2010.
The Michigan failure bore similarities to the Jan. 31, 2025, leak along Twin Oaks in Upper Makefield Township, Pennsylvania, where petroleum escaped beneath a repair sleeve and contaminated nearby soil and groundwater.
Although the failures involved different types of sleeves, federal investigators identified broader concerns about the company’s ability to document, inspect and establish the integrity of such repairs.
According to the order, 45 Type A repair sleeves were installed along Twin Oaks between 1987 and 1999. Energy Transfer lacked original repair records for five, including the one involved in the Pennsylvania failure. In Michigan, records were missing for the failed sleeve and 11 others.
The order also identified missing original repair documentation for hundreds of additional sleeves across Energy Transfer’s hazardous-liquid pipeline network.
PHMSA warned that steel sleeves can interfere with internal inspection technologies, potentially concealing corrosion or other defects. Regulators concluded that conditions associated with the two failures could remain elsewhere in the company’s system and result in additional failures if not addressed.
The order requires Energy Transfer to inventory its steel repair sleeves, review previous inspection results and develop plans to evaluate and address potential defects. Sleeves whose integrity cannot reasonably be assured must be removed.
The requirements apply across Energy Transfer’s hazardous-liquid pipeline network. The order also directs the company to keep an approximately 16-mile section of the Michigan pipeline shut down and imposes a 20% operating-pressure reduction on the broader Marysville-Toledo line.
No comparable shutdown or new pressure restriction was imposed on Twin Oaks.
The September order builds on concerns identified after the Pennsylvania leak. Under a May 2025 consent agreement, PHMSA required Sunoco to investigate repair sleeves along Twin Oaks, including at least 10 with configurations and potential corrosion risks similar to the failed sleeve.
Federal officials also said the Pennsylvania leak was discovered after residents reported fuel odors, rather than through the company’s internal leak detection equipment.
Riverkeeper calls for shutdown
For Delaware Riverkeeper Network, the latest findings provide new reasons to question whether Twin Oaks should continue operating while the condition of its repairs is evaluated.
“I think it widened it, and it made it a much bigger deal,” Tracy Carluccio, deputy director of Delaware Riverkeeper Network, said in an interview with MercerMe about the September order.
Carluccio pointed to missing repair records and the challenges of inspecting pipe beneath steel sleeves. She questioned whether the company could ultimately demonstrate that all existing sleeves can safely remain in place.
Riverkeeper renewed its shutdown demand in an Oct. 21 letter to New Jersey Department of Environmental Protection Commissioner Ed Potosnak. The organization also urged Pennsylvania environmental officials to press PHMSA for a shutdown while investigations and corrective measures continue.
“Once it leaks, it’s your problem, and it could be leaking right now, and you’re just sitting on the sidelines,” Carluccio said.
The January 2025 Twin Oaks failure in Upper Makefield Township prompted an extensive investigation into contaminated groundwater and drinking water supplies. Carluccio said Riverkeeper remains concerned that the full extent of the contamination has not been established.
“My understanding is that they have not what they call ‘fully delineated’ the pollution plume,” she said.
According to Carluccio, much of the initial testing and response has been concentrated within 500 feet of the leak site. Riverkeeper wants testing expanded, particularly toward the Delaware River, citing concerns about groundwater movement.
Questions about New Jersey oversight
Riverkeeper has repeatedly sought information from NJDEP about pipeline inspections, environmental monitoring and coordination with federal regulators.
In a Sept. 24 letter, the organization outlined correspondence dating to July 2025, followed by additional inquiries in September 2025 and January and March 2026. Riverkeeper said it had not received substantive answers about what investigation, if any, was occurring along the New Jersey section.
The letter also cited a 2025 PHMSA warning after Sunoco did not allow federal inspectors to photograph contractors’ field notes during Twin Oaks remediation work. PHMSA identified a probable violation but did not pursue additional enforcement or penalties at that time.
Carluccio said NJDEP recently acknowledged Riverkeeper’s correspondence and indicated that it had been assigned to a team for review.
Questions about the state’s involvement are not new. In July 2025, NJDEP confirmed to MercerMe that it was not participating in monitoring Twin Oaks. At the time, PHMSA officials said there was no indication of a release on the New Jersey side and therefore no reason for NJDEP to become involved.
MercerMe contacted NJDEP again Oct. 23, asking whether it had conducted any investigation or environmental monitoring, communicated with PHMSA, received information about repair sleeves in New Jersey or considered Riverkeeper’s shutdown request.
The department responded with one sentence: “Regulatory jurisdiction for pipeline safety falls under FERC.”
PHMSA, part of the U.S. Department of Transportation, regulates interstate hazardous-liquid pipeline safety. The Federal Energy Regulatory Commission, or FERC, has a separate role involving economic regulation of interstate oil pipelines.
NJDEP did not address questions about its environmental responsibilities, monitoring activities or coordination with federal regulators, leaving unclear whether its involvement has changed since 2025.
Carluccio said Riverkeeper is not asking NJDEP to assume PHMSA’s responsibilities but wants state environmental officials to advocate for protective measures and help make information available to the public.
The organization has also called for public meetings where residents could hear directly from regulators and the pipeline operator about inspections, repairs and the investigations.
The federal order requires Energy Transfer to review previous inspection results within 30 days, prepare a systemwide sleeve inventory within 90 days and develop plans to evaluate and address sleeves within 120 days of receiving the order.
The company must also submit quarterly progress reports to PHMSA, with the first due Nov. 1.
PHMSA told MercerMe that its investigations of the Pennsylvania and Michigan failures remain ongoing and that additional corrective measures could be imposed.
Pipeline concerns reach local planners
The pipeline’s condition has also been a recurring concern in Hopewell Township’s land-use discussions.
During hearings on the proposed 600-unit Venue at Hopewell development along Nursery and Scotch roads in 2025, residents repeatedly questioned the safety of building around Twin Oaks, which runs through the property along an established easement.
At a December Planning Board hearing, residents raised concerns about the aging pipeline, previous repairs, groundwater contamination and whether construction activity could affect the line. The board subsequently approved the development’s site plan.
Those concerns resurfaced this month when Riverkeeper sent an Oct. 21 letter to the Mercer County Planning Commission highlighting the pipeline’s route through the Venue property and requesting a comprehensive environmental impact study before the county takes action on the project.
The letter urged county officials to consider the latest federal pipeline findings in their review.
The correspondence was copied to the Hopewell Township Planning Board, which acknowledged it during the correspondence portion of its Oct. 22 meeting. Members briefly discussed the information but did not identify a specific action for the board to take.
The discussion brought the new federal findings into a local land-use issue that had already generated substantial public concern.
For residents along the Twin Oaks route, the September order raises questions about the condition of a pipeline that has operated for nearly seven decades and what the new federal review will reveal about repairs along its New Jersey route.
