Leidy South

What’s inside of a FERC application?

Staff Reports

Williams is currently working to develop a Certificate Application for the Leidy South project that will be filed with the Federal Energy Regulatory Commission (FERC) later this summer.

The Leidy South Project is a proposed expansion of Williams’ existing Pennsylvania energy infrastructure in time for the 2021-22 winter heating season.

FERC regulates the siting and construction of interstate natural gas pipelines. An integral component to FERC’s review of a proposed project is the Application for a Certificate of Public Convenience and Necessity (Certificate Application). The Certificate Application is a comprehensive document that describes the proposed project, its need and potential environmental impacts.

We are often asked about the contents of a formal Certificate Application. Here is a brief summary of the major components that you can expect the Certificate Application to contain:

Description of Proposed Facilities

A description of the new facilities and an overview of their location and cost.

Market Support

Identification of the customers who have executed contracts to be part of the project, as well as the gas volumes that they have requested.


Description of the proposed rates that project customers will pay for the gas service.

Public Convenience and Necessity

Included is a description of the company’s efforts to minimize or eliminate potential adverse effects, including impacts to customers, landowners and the environment. This section also demonstrates how the public benefits of the project outweigh potential adverse effects.

Timing for Approval

The estimated in-service date, as well as a request for the date in which the company would like to receive approval of the application.

Other Exhibits

Included in the Certificate Application are many exhibits that support the proposal, such as detailed maps, market and cost data, as well as comprehensive environmental “Resource Reports.” These reports detail the various studies and analyses which have been conducted to determine what effect construction and operation could potentially have on the environment and community and how those effects can be effectively minimized or eliminated.

Environmental Resource Reports include an analysis of route and facility alternatives, as well as an analysis of potential impacts to water resources including wetlands and groundwater, vegetation and wildlife including threatened and endangered species, cultural resources, socioeconomics, soils, geology, land use including proposed developments and, noise and air quality, alternatives, and safety.

When the Certificate Application is filed and a Certificate Proceeding (CP) docket number is assigned, a copy of the entire application will be made available for viewing at public libraries, as well as via the FERC website by referencing the project’s docket number.

Please note that the application will contain detailed drawings and schematics of facilities that are considered Critical Energy Infrastructure Information (CEII). Those materials are not available electronically.

We anticipate that once the Certificate Application is filed, the FERC will require an additional 12 to 14 months to make a final decision on whether to issue a Certificate Order authorizing construction of the Leidy South project. If authorized, the Certificate Order will detail the conditions of the approval, including the final route that FERC has authorized, and construction and mitigation measures that we must follow.