Hillabee Expansion

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 pipeline

Transco pipeline

Williams, a leading energy infrastructure company, has developed an expansion of its existing Transco pipeline to serve the growing need for natural gas by local utilities, industries and power generators in the southeastern United States.   The Hillabee Expansion Project is designed to expand the existing Transco pipeline’s capacity in Alabama beginning in the second quarter of 2017, supplying gas to the proposed Sabal Trail pipeline.

The Hillabee Expansion is designed to be constructed in three phases, adding a total of approximately 1,131,000 dekatherms per day (dt/d) of pipeline capacity to the Transco system by 2021 (enough natural gas to meet the needs of over 4 million American homes annually).

  2017 2020 2021
Looping 20.1 miles 10.6 miles 12.8 miles
Compression 68,500 hp 19,500 hp 0 hp
Capacity 818 Mdt/d 206 Mdt/d 106 Mdt/d


The proposal would involve the construction of approximately 43 miles of additional pipe segments (called loops) in Alabama, in addition to modifying some existing pipeline facilities.

Hillabee thumb

Project location map

As part of the Hillabee Expansion, Williams is proposing the construction of eight new pipe sections (loops),  a new compressor facility in Choctaw County, Ala., as well as making modifications to other existing compressor stations and valve sites. The pipeline loops vary in length and are expected to parallel the existing Transco pipeline, 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.

Proposed major facility modifications:

Phase I (2017 In-Service)
State County Scope
AL Choctaw New 32,000 hp compressor facility
AL Dallas Existing compressor facility modifications
AL Autauga / Chilton 4.6 miles of 48-inch pipe
AL Coosa 5.3 miles of 42-inch pipe
AL Coosa 2.55 miles of 42-inch pipe
AL Coosa Existing compressor facility modifications
AL Tallapoosa 7.6 miles of 42-inch pipe


Phase II (2020 In-Service)
State County Scope
AL Choctaw 6.73 miles of 42-inch pipe
AL Dallas Existing compressor facility modifications
AL Chilton Existing compressor facility modifications
AL Chilton 3.92 miles of 42-inch pipe


Phase III (2021 In-Service)
State County Scope
AL Choctaw 5.48 miles of 42-inch pipe
AL Chilton Existing compressor facility modifications
AL Chilton / Autauga 7.48 miles of 42-inch pipe
Selecting Facility Locations

DSC00747In developing the pipeline project, engineers attempt 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.

Ground Surveys

1Survey3Ground surveys are a pre­liminary first step in gathering critical information that can be used in devel­oping the pipeline proposal.  Initial ground surveys (environmental, cultural and civil surveys) for the Hillabee Expansion project began in November 2013.  After receiving permission from the landowner, each property is visited by various specialists in land, engineering and environmental sciences. These may or may not be con­current visits but should not last longer than one or two days each. Some prop­erties may need to be revisited to obtain additional data. All information col­lected will be used to help determine the best location of the proposed pipeline facilities.

Permitting Process

Before any new pipeline facilities can be constructed, Williams must first obtain a federal Certificate of Public Convenience and Necessity from the Federal Energy Regulatory Commission (FERC), in addition to various state and local permits. In November 2014 Williams submitted its 7c Certificate Application to FERC (CP15-16). The project was approved by the FERC in February 2016. All project documentation can be accessed at the FERC website by referencing the docket number.

  • November 2013 – Pre-filing process began
  • November 2013 – Detailed civil surveys began and are ongoing
  • January 2014 – Open houses and informational meetings
  • First quarter 2014 – FERC scoping hearings
  • November 2014 – Submit 7(c) application to FERC
  • February 2016 — FERC approval
  • Second Quarter 2017 – Phase I in-service
  • Second Quarter 2020 – Phase II in-service
  • Second Quarter 2021 – Phase III 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.

Phone: 713-215-2264
Email: PipelineExpansion@williams.com

You may also call or write our land office:

1600 Executive Dr South
Suite 200
Duluth, GA  30096