Natural Gas
Federal Court Nullifies New Jersey Approval for $1B Gas Pipeline to New York City
Appeals court finds monitoring requirements unresolved for Northeast Supply Enhancement line before Raritan Bay dredging could begin
A federal appeals court has vacated New Jersey's water-quality certification for Williams Cos.' more-than-$1-billion Northeast Supply Enhancement natural gas pipeline, finding state regulators left critical monitoring requirements unresolved and inadequately explained how Raritan Bay dredging would meet state standards.
The U.S. Court of Appeals in Philadelphia on Sept. 8 sent the Clean Water Act Section 401 certification back to the New Jersey Dept. of Environmental Protection for further proceedings.
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Court of Appeals —
Natural Resources Def. Council v. N.J. Dept. of Environmental Protection
The decision comes less than three weeks after a separate federal appeals court upheld New York's water-quality certification for the same project. ENR reported Aug. 24 that state approval requires review of compliance plans before applicable construction can begin, as well as an independent third-party monitor with stop-work authority and specified pollutant limits. The court cited those safeguards in distinguishing New York's approval from New Jersey's.
Williams' Northeast Supply Enhancement project would add 400,000 dekatherms per day of pipeline capacity into a Northeast gas market supplied by multiple regions, storage, local production and LNG.
Graphic courtesy AOGR
The pipeline would add roughly 37 miles of line capacity and related facilities to Williams subsidiary Transcontinental Gas Pipe Line Co.'s system, increasing it by 400,000 dekatherms per day to serve National Grid customers in New York City and Long Island. Williams continues to target fourth-quarter 2027 service.
Williams spokesperson Cherice Corley told Reuters by email that the company is working with state regulators to address the court's findings and remains committed to advancing the project.
"At this time, we do not expect the decision to adversely affect project construction or the anticipated in-service timeline," she said.
Ben Dziobek, executive director of Climate Revolution Action Network, called the decision a win for communities along Raritan Bay. "No fossil fuel company—no matter how much political support it has in Washington—gets to cut corners on the protections our communities are entitled to," he said. A coalition of environmental groups filed suit last November against the decision.
In New Jersey, work includes a new compressor station in Somerset County, the 3.4-mile Madison Loop in Middlesex County and about six miles of offshore pipeline in Raritan Bay. Installation of the underwater segment requires dredging a trench, placing the pipe and backfilling it.
The court said sediment along the route contains contaminants including arsenic, manganese, mercury, polychlorinated biphenyls and 4,4'-DDE, a breakdown product of DDT.
Monitoring Requirements Left Unresolved
New Jersey Dept. of Environmental Protection and New York regulators issued their Section 401 certifications on Nov. 7, 2025.
The New Jersey certification required Transco to submit water-quality monitoring and adaptive-management plans but did not make agency approval of those plans a prerequisite to dredging. Material questions remained unresolved, the court said, including thresholds that would trigger mitigation measures, how quickly exceedances must be reported and whether dredging would stop if corrective measures failed.
The NESE project's Raritan Bay Loop crosses New Jersey and New York waters, where planned underwater pipeline construction requires dredging and backfilling along the route. Click to enlarge.
Map courtesy Williams Cos.
"No prescribed NJDEP approval stands between the unfinished plans and dredging," the court said.
Transco's modeling predicted concentrations of 4,4'-DDE at two sampling locations 500 ft from dredging that exceeded New Jersey's human-health criterion. At one location, the modeled concentration was more than 13 times the criterion. The final certification reduced the allowable dredging rate and required work during slack tide in that area, but the court said DDE concentrations were not recalculated under those operating conditions.
New Jersey Dept. of Environmental Protection also required monitoring for turbidity but not the toxic contaminants themselves. The court said the agency had not explained why monitoring water cloudiness would assure compliance with standards governing DDE, PCBs, mercury and other contaminants.
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Judges also found the department attributed to state marine experts a prediction that affected surf-clam populations would recover within one to three years when the prediction actually came from Transco.
The court found that unresolved compliance measures and inadequately explained technical findings made the certification arbitrary and capricious. Because those defects required vacatur, judges did not decide environmental groups' separate claims concerning the public-comment process.
New Jersey Dept. of Environmental Protection is not required to reject the project on remand. The court said the agency may supplement its explanation, require additional submissions or analyses, issue a new or revised certification or reach a different result.