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Iroquois Gas Transmission System

The Iroquois Gas Transmission System (Iroquois) maintains key market connections into New York City and serves regional local distribution companies and power plants in the Northeast.  


Iroquois compressor facility


Iroquois map

Asset information

TCP Ownership

0.7% held by a subsidiary of TC Energy
50% owned by affiliates of Dominion Energy, Inc.

Began operations



416 miles


1.5 Bcf/d

Compressor stations


Primary supply source

Iroquois/Waddington interconnect

Originates near:

Waddington, New York

Terminates near

Hunts Point, Bronx, New York

Primary markets served

Iroquois Zone 2 interconnect, New York/Long Island and Connecticut

Organic growth projects

Iroquois is developing and permitting upgrades to its compression facilities in response to increasing demand for cleaner energy from fuel switching and economic growth. If successful, the Enhancement by Compression (ExC) project has the potential to optimize the Iroquois system to meet current and future gas supply needs of utility customers while minimizing environmental impact through compressor enhancements at existing compressor stations along the pipeline. The project’s total capacity is expected to be approximately 125,000 Dth/day with an estimated in-service date in November 2023.  This project is underpinned by contracts for 20-year terms with local distribution companies.

Documents and Maps

For more information, visit the Iroquois Gas Transmission Website

ExC Project