The Islander East Pipeline was a proposed interstate natural gas pipeline that could supply natural gas in Connecticut, New York City, and Long Island, N.Y. Spectra Energy and KeySpan Energy were to co-own the pipeline.

The pipeline would have extended from North Haven, Conn., across Long Island Sound to the vicinity of Yaphank, N.Y. The Islander East facilities would have consisted of 50 miles of new 24-inch diameter pipeline with initial capacity of 260,000 dekatherms of natural gas per day.

The project entailed performing certain upgrades to an existing pipeline system in Connecticut that would have interconnected with Islander East pipeline. Approximately 13.7 miles of existing parallel pipelines were slated for upgrades and a new compressor was to be built in Cheshire, Conn. The plans called for 22 miles of underwater pipe that would enter Long Island Sound in Branford, Conn., near the Thimble Islands and cross the floor of the Sound.

Approximately one mile of the pipeline route was in dispute because it passed through the environmentally sensitive Thimble Islands region south of the Connecticut coastline. In February 2009, Connecticut's governor and attorney general -- both opponents of the project -- declared the project "dead" because Spectra had withdrawn its appeal to the U.S. Department of Commerce to overturn the state's denial of permits for the project. Previously, the U.S. Supreme Court let stand the state's refusal is issue a water quality permit.