DEC Statement on Water Quality Certification for Proposed Northeast Supply Enhancement Pipeline Project

The New York State Department of Environmental Conservation (DEC) today announced the agency's approval of required permits, including a Clean Water Act Section 401 Water Quality Certification, for the proposed Northeast Supply Enhancement (NESE) pipeline project. The full decision is outlined in a letter issued today to Transcontinental Gas Pipe Line Company, LLC.

DEC subjects all applications for environmental permits to an extensive and transparent review process to ensure the protection of public health and the environment. DEC's review process for interstate natural gas pipeline applications is project-specific, varying by the type and scope of the application, and is guided by stringent State and federal environmental laws and regulations.

Reviews are limited to the scope of the State's regulatory authority. They include any applicable federal requirements, which in the case of NESE, includes changes since 2020, such as the 2023 U.S. Environmental Protection Agency Clean Water Act rulemaking and guidance executed after DEC's 2020 review of the NESE Water Quality Certification application; all public comments; availability of project-specific conditions consistent with State requirements to avoid or significantly minimize potential project impacts; other recently constructed projects that required in-water construction activities; and substantive revisions to ecological considerations, such as a correction to the hard clam density that was considered in the 2020 application.

DEC's comprehensive review of the May 2025 NESE application materials also included supporting materials provided by the applicant, an extended public comment period, and more than 17,000 new public comments received on the project.

The letter, responsiveness summary to public comments, information about the Water Quality Certification, and other supporting materials are available on DEC's Northeast Supply Enhancement Project (NESE) webpage.

DEC is requiring a range of environmentally protective conditions in the NESE Water Quality Certification that include:  

• comprehensive oversight: DEC is requiring on-site, independent, third-party monitors that will directly oversee project implementation to ensure compliance. All reporting and monitoring will be conducted in accordance with DEC-approved plans; 
• minimizing and mitigating impacts to critical resources, including Atlantic and shortnose sturgeon, winter flounder, and hard clams; construction work windows to avoid sediment disturbance during critical times of year to protect the life cycles of hard clams and minimize impacts to aquatic species; requiring the project developer to implement mitigation for all unavoidable impacts, which is estimated to cost approximately $23.5 million, pending DEC's ongoing assessment; and 
• preventing contaminants from contravening water quality in the Raritan and Lower New York bays: the project developer must implement a Dredge Management Plan that limits contaminants from being suspended in the water column and details adaptive management techniques. 

DEC is committed to closely monitoring the project's construction and adherence to all permit conditions to ensure the full protection of New York's waterways.

In addition, the Constitution Pipeline Company, LLC today withdrew its application for permits, including the required Clean Water Act Section 401 Water Quality Certification, for the proposed Constitution pipeline project. The withdrawal follows DEC's legally required comprehensive evaluation of the application materials and DEC's issuance of three Notices of Incomplete Application for insufficient information. Constitution also failed to take action on the federal level at the Federal Energy Regulatory Commission, the lead agency for interstate pipelines. DEC's July 2, August 26, and September 30, 2025, notices detailed the requirements necessary to meet the State's thresholds for an application to be determined complete for public review and comment. The Constitution Pipeline Company did not fulfill these repeated information requests and, on November 7, 2025, formally withdrew the application from further consideration. View the withdrawal notice (PDF).