When Williams develops a pipeline project, we work hard to balance environmental concerns, landowner considerations, and the engineering requirements for safely constructing a transmission pipeline

Selecting facility locations

Sophisticated computer modeling is used to identify what new pipeline facilities will be required to create the necessary capacity requested by the project customers. Increasing natural gas deliveries can be accomplished through one or a combination of the following:

  • Increasing horsepower at pipeline compressor stations or building new compressor stations
  • Replacing existing pipeline with larger pipeline
  • Building new pipeline, either next to existing pipes or in an area where pipelines don’t currently exist (sometimes referred to as “greenfield” pipelines).

All three of these approaches are being used for the Atlantic Sunrise project.

Further Evaluations

Williams also evaluates a number of environmental factors, including potential impacts on:

  • residents
  • threatened and endangered species
  • wetlands
  • waterways
  • groundwater
  • vegetation
  • fish
  • wildlife
  • cultural resources
  • geology
  • land use
  • air and noise quality

Williams strongly considers routes along existing corridors, such as pipeline rights of way, roadways, utility corridors, railroad corridors and other easements. After analyzing maps, aerial photos, environmental reports and other data, pipeline engineers establish a preliminary route or location for the new facilities, as well as location alternatives.

Facilities Locations Under Review

  • A 57.39‑mile, 30-inch greenfield pipeline on Transco’s Leidy Line in Columbia County, Pa., to the proposed Zick Meter Station in Susquehanna County, Pa. (“Central Penn Line North”)
  • A 126.31‑mile, 42-inch greenfield pipeline on Transco’s mainline in Lancaster County, Pa., to Transco’s Leidy Line in Columbia County, Pa. (“Central Penn Line South”)
  • 2.92 miles of 36-inch diameter pipeline loop on Transco’s Leidy Line in Clinton County, Pa. (“Chapman Loop”)
  • 8.56 miles of 42-inch diameter pipeline loop on Transco’s Leidy Line in Lycoming County, Pa. (“Unity Loop”)
  • Replacement of 2.52 miles of 30‑inch diameter pipeline in various non-contiguous segments in Prince William County, Va. (“Mainline A & B Replacements”)
  • A 30,000 horsepower electric motor-driven greenfield compressor station on the Central Penn Line North, in Wyoming County, Pa. (“Compressor Station 605”)
  • A 40,000 horsepower electric motor-driven greenfield compressor station on the Central Penn Line South, in Columbia County, Pa. (“Compressor Station 610”)
  • The addition of 62,000 (ISO) turbine driven horsepower at three of Transco’s existing compressor stations in Pennsylvania and Maryland.
  • Two new meter stations and three new regulator stations with interconnecting piping in Pennsylvania.
  • Modifications at existing compressor stations in Maryland, Virginia, and North Carolina to enable compression for bi-directional flow.
  • Related appurtenant underground and aboveground facilities.

More detailed maps are available for viewing in the Certificate Application filed with FERC.