SH2DF Project Filed an Application with the NYSDPS

PSEG Long Island, on behalf of the Long Island Power Authority (LIPA), filed an Application for a Certificate of Environmental Compatibility and Public Need (CECPN) with the New York State Public Service Commission (PSC), Friday, February 16, 2024 (Case 24-T-0113).

Public Information Session held 12/6

Members of the PSEG Long Island public outreach teams and their contractors held a Public Information Session on Wednesday December 6th, 2023 at the Rogers Memorial Library. All information shared at the event are available on the website.

Permitting the Southampton to Deerfield Project

See "About the Project" to learn more about the need for the Southampton to Deerfield Project, and the New York State Public Service Commission process.

Construction Process

Read about how the construction process for a new underground transmission line happens.

News & Events

  • 2024
  • 2023

Project Application Filed for CECPN with the NYSPSC

PSEG Long Island, on behalf of the Long Island Power Authority (LIPA), filed an Application for a Certificate of Environmental Compatibility and Public Need (CECPN) with the New York State Public Service Commission (PSC) today, Friday, February 16, 2024, for a new 138kV underground electric transmission project in the Town and Village of Southampton called the "Southampton to Deerfield Transmission Project," or "SHDF"(Case 24-T-0113). The project is to provide further reliability and resiliency to the South Fork electric grid for years to come. 
Please read the important documents below for more information on this project, or contact us directly at 631-237-7196 or via email at for questions.

Article VII Pre-Filing abutting landowner notifications

Letters have been mailed to abutting landowners alerting them that the Project intends to file the Article VII application on or about February 16, 2024. /assets/document-library/SHDF Article VII Pre-Filing Abutting landowner letter.pdf

Public Information Session held 12/6/23

December 6, 2023 Public Information Session

PSEG Long Island held a Public Information Session on Wednesday December 6, 2023 at the Rogers Memorial Library in Southampton. The event welcomed community members to meet with the project team and learn about the project.  Questions were answered and input was taken from visitors.  All materials from the event are available on the website under the Open House tab. 

December 2023 Public Information Session Materials

Fact Sheets

Southampton to Deerfield Transmission Project - Fact Sheet - 10/16/2023 - 406 KB
Proyecto de transmission de Southampton a Deerfield - 10/16/2023 - 463 KB
Article VII Fact Sheet - 11/15/2023 - 261 KB

Aerial Views

Aerial of Deerfield Substation - 11/15/2023 - 13.48 MB
Aerial of Southampton Substation - 11/15/2023 - 12.63 MB


Overview of Southampton to Deerfield Routing Options - 11/15/2023 - 45.04 MB
Proposed Route Map - 11/15/2023 - 59.26 MB

Open House Exhibits

Construction Boards - 12/06/2023 - 1.33 MB
Project Description - 12/06/2023 - 198 KB
Routing Methodology - 12/06/2023 - 191 KB

About the Project

Project Overview and Benefits

PSEG Long Island, as the agent of LIPA, is proposing a new underground electric transmission project to increase the load capacity and reliability of the electric transmission system on Long Island. Called the Southampton to Deerfield Transmission Project ("SHDF Project" or "Project"), its principal component is the installation of a new underground 138 kilovolt (kV) transmission line between the existing Southampton Substation (located in the Village of Southampton at the intersection of North Sea Road and West Prospect Street) and the existing Deerfield Substation (located in the Hamlet of Watermill on Water Mill Towd Road) primarily along roadways and existing municipal rights-of-way. The SHDF Project is the most cost-effective solution to meet the South Fork's increasing electrical demand and need for reliable electrical service while minimizing disruptions to the community. The Project also is consistent with and furthers the goals of the New York's Climate Leadership and Community Protection Act by supporting the transmission of wind energy on Long Island.

Benefits Include:

The new 138kV electric transmission cable will help ensure continued reliable service to the East End of Long Island. With the South Fork load continually growing, the proposed 138kV supply circuit from the Southampton Substation to the Deerfield Substation will enhance reliability and add redundancy to the existing transmission system.

The new 138kV cable will be located entirely underground except for certain above-ground electrical equipment within the existing substations.

The Project will be located primarily under roads and other public rights-of-way.

Construction of the Project will occur with the least amount of impact to residents and travelers in the area. Throughout construction, access to businesses and residences along the Project route will be maintained. 

New York State Public Service Commission Article VII and EM&CP Information

The Project's Public Service Law Article VII application and related documents in this case (Case XXX) can be accessed from the PSC's website ( Click "Commission File" and then "'File Search” to go to the Search page, then fill in the "Search by Case Number” box with the number for this case (XXX). This will bring up the main Document and Matter Management ("DMM”) page(s) for this case, where the materials are located. 

In addition, interested persons who wish to participate as parties in this case may file for party status. On the DMM page for this case, the prospective party should click the button at the upper right labeled "Request for Party Status” to see a PSC web page with instructions for the procedures to follow to become a party.

Permitting & Consultation Process

To construct the Project, PSEG Long Island will need, in addition to other necessary permits:

  • The New York State Public Service Commission's issuance of an Article VII Certificate of Environmental Compatibility and Public Need and approval of an Environment Management & Construction Plan (EM&CP).
  • Approval from or consultation with the New York Department of Environmental Conservation, New York State DOT, and New York State Office of Parks, Recreation & Historic Preservation.
  • Consultation with Suffolk County, Town of Southampton, and Village of Southampton.

Document Library

Construction Process

Underground Transmission Construction Process Overview

Construction of the Project will occur primarily along North Sea Road, Willow Street, North Main Street, North Sea Mecox Road, David Whites Lane, Edge of Woods Road, and Water Mill Towd Road in the Town of Southampton, thus minimizing impacts to residents and travelers to the area.

Underground Construction Involves Five Key Phases

Splice Vaults Installation

Underground vaults will be installed at intervals along the route to splice together underground cable.

Conduit Installation

During the installation process, crews will route the new conduits to the new splice vaults. 


After completing the installation of the vaults, any excavated and disturbed areas will be restored.

Cable Installation

Underground cable arrives on trucks specifically designed for their installation. Crews will pull cable from one vault to another along the project route.

Cable Splicing

Crews will set up a climate-controlled environment at each vault location to splice the underground cables together. This activity is continuous for approximately one week for each vault.


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