Williams Transco Pipeline Our Fight Against the Williams Transco Pipeline About the Proposed Pipeline Williams Transco has proposed a 23.4-mile, 26-inch diameter pipeline project to expand its existing Transco transmission system to transport natural gas from the Marcellus Shale region through Raritan Bay to New York. Construction of the pipeline poses a threat to air and water quality and 14,000 acres of habitat for clams, horseshoe crabs, fish and other marine animals. This is a step backwards both for energy policy and the environment by committing the region to more fossil fuel infrastructure projects that may be unnecessary or make it more difficult for renewables to enter the market.