Leidy Southeast

Historically low natural gas prices and the public’s desire for cleaner energy have fueled the growing popularity of natural gas. Clean-burning natural gas currently produces one-third of all electric generation and heats about half of all U.S. homes – and those numbers continue to climb.

transco simple mapWilliams, a leading energy infrastructure company, is expanding its existing Transco natural gas transmission pipeline to serve the growing needs of local gas distribution companies along the Atlantic Seaboard by the 2015 winter heating season. The Transco pipeline is a major transporter of natural gas in the southeast and northeastern United States.

The Leidy Southeast Expansion Project will increase the Transco pipeline’s capacity by 525,000 dekatherms of natural gas per day (enough natural gas to serve about 2 million homes). The project will involve the construction of approximately 30 miles of additional pipe segments, called loops, in Pennsylvania and New Jersey, in addition to modifying some existing pipeline facilities.


As part of the Leidy Southeast Expansion, Williams is constructing four new pipe sections (loops), as well as making modifications to various existing compressor stations and valve sites. The pipeline loops vary in length and will parallel the existing Transco pipeline, either completely within or adjacent to the existing utility corridor. By maximizing the use of our existing transmission corridor, our goal is to minimize the impact on property owners and the environment.

Major Facility Modifications
State County Scope
PA Luzerne 5.31 miles of 42-inch pipe (Dorrance Loop)
PA Luzerne / Monroe 11.47 miles of 42-inch pipe (Franklin Loop)
PA Luzerne Existing compressor facility modifications
PA Lycoming Existing compressor facility modifications
PA Columbia Existing compressor facility modifications
NJ Somerset / Hunterdon 6.92 miles of 42-inch pipe (Pleasant Run Loop)
NJ Somerset / Mercer 6.18 miles of 42-inch pipe (Skillman Loop)
NJ Mercer Existing compressor facility modifications


Selecting Facility Locations

In developing the pipeline project, engineers attempted to balance environmental and landowner considerations with the engineering requirements for safely constructing a transmission pipeline. These factors include geography, environmental concerns, collocation with other linear development and constructability.

Sophisticated computer modeling is used to identify what new pipeline facilities will be required to create the necessary pipeline 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).

The pipeline company must evaluate a number of environmental factors, including potential impacts on residents, threatened and endangered species, wetlands, water bodies, groundwater, fish, vegetation, wildlife, cultural resources, geology, soils, land use, air and noise quality.

Pipeline companies are strongly encouraged by federal regulators to consider 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 available data, pipeline engineers establish a preliminary route or location for the new facilities, as well as location alternatives.

Permitting Process


In January 2013 Williams requested that the Federal Energy Regulatory Commisison initiate a pre-filing environmental review of the proposed pipeline project. The project was assigned pre-filing docket number PF13-5. All pre-filing documentation can be accessed at the FERC website by referencing the pre-filing docket number.

The FERC pre-filing process is intended to solicit early input from citizens, governmental entities and other interested parties to identify and address issues with potential facility locations. The company hosted a series of public open houses during the spring of 2013 in the affected areas to formally introduce the proposal to the public and solicit feedback. Public input is important to the project and can shape the final project footprint.

Filing of 7(c) Applicaiton
Williams filed an application with FERC on Sept. 30, 2013, seeking approval to construct the Leidy Southeast project. The Commission approved the project on Dec. 18, 2014.

The Certificate Application is a comprehensive document that describes the proposed project, its need and potential environmental impacts. The project was assigned Docket Number CP13-551. All documents and correspondence submitted to or issued by FERC regarding the project can be accessed by referencing the Docket Number on the FERC website located at http://elibrary.ferc.gov/idmws/search/fercgensearch.asp.


  • January 2013 – Detailed civil surveys began and are ongoing
  • January 2013 – Pre-filing process began
  • April 2013 – Open houses and informational meetings
  • Summer 2013 – FERC scoping hearings
  • Summer 2013 – Submit draft environmental reports to FERC
  • September 2013 – Submit 7(c) application to FERC
  • Fall 2014 – Proposed compressor station construction start
  • December 2014 — FERC approval
  • Spring 2015 – Pipeline construction start
  • December 2015 – Target in-service

Our Commitment

Williams is committed to working with landowners, as well as local, state and federal agencies, to design and construct the project in a manner that minimizes environmental and landowner impacts. The company is committed to extensive public outreach in advance of submitting our application to the FERC. Our goals are to:

  • Generate a broad awareness of the project, its purposes and value to the region’s economy and to meeting the future energy needs of the state and region.
  • Ensure that community residents and a broad range of stakeholders have ample opportunity to understand the process and their rights, ask questions, voice concerns and present ideas about the project.
  • Create an atmosphere of openness, disclosure and public dialogue in which we can respond to questions, concerns and suggestions presented by the community and other stakeholders.

Contact Us

If you have any questions, feel free to contact us anytime.

Toll-free hotline: 866-455-9103
Email: PipelineExpansion@williams.com

You may also call or write our land office:

95 Highland Ave, Suite 150
Bethlehem, Pa. 18017