Project CP23-3-000

The staff of the Federal Energy Regulatory Commission (FERC or Commission) has prepared an environmental assessment (EA) for the Tres Palacios Cavern 4 Expansion Project, proposed by Tres Palacios Gas Storage LLC (Tres Palacios) in the above-referenced docket. Tres Palacios requests authorization to expand its certificated natural gas storage capacity at its existing natural gas storage facility (the Storage Facility) in Matagorda County, Texas.

The EA assesses the potential environmental effects of the construction and operation of the Tres Palacios Cavern 4 Expansion Project in accordance with the requirements of the National Environmental Policy Act (NEPA). The FERC staff concludes that approval of the proposed project, with appropriate mitigating measures, would not constitute a major federal action significantly affecting the quality of the human environment.

The proposed Tres Palacios Cavern 4 Expansion Project includes the following facilities and activities:

  • conversion of an existing third-party brine production well (Trull 11) into a natural gas storage cavern (Cavern 4);
  • development of the Trull 11 well pad site for Cavern 4 (Cavern 4 Well Pad);
  • construction of a 0.6-mile-long, 16-inch-diameter pipeline (new Cavern 4 Pipeline) including cathodic protection along the proposed pipeline, connecting Cavern 4 to the certificated facilities at the existing Storage Facility;
  • abandonment in place of a 15,300 horsepower (HP) electric-motor driven centrifugal compressor unit;
  • installation of a new 5,500 HP electric-motor driven reciprocating compressor unit;
  • addition of a new 2.5 million British thermal units per hour dehydration unit;
  • construction of various related facilities, including a new permanent access road for the Cavern 4 Well Pad; and
  • non-jurisdictional facilities consisting of a new electric service line to the Cavern 4 Well Pad and a new fiber optic line from the Cavern 4 Well Pad to the Storage Facility.

The Commission mailed a copy of the Notice of Availability of the EA to federal, state, and local government representatives and agencies; elected officials; environmental and public interest groups; Native American tribes; potentially affected landowners and other interested individuals and groups; and newspapers and a library in the project area. The EA is only available in electronic format. It may be viewed and downloaded from the FERC’s website (, on the natural gas environmental documents page ( In addition, the EA may be accessed by using the eLibrary link on the FERC’s website. Click on the eLibrary link (, select “General Search” and enter the docket number in the “Docket Number” field, excluding the last three digits (i.e., CP23-3). Be sure you have selected an appropriate date range. For assistance, please contact FERC Online Support at or toll free at (866) 208-3676, or for TTY, contact (202) 502-8659.

The EA is not a decision document. It presents Commission staff’s independent analysis of the environmental issues for the Commission to consider when addressing the merits of all issues in this proceeding. Any person wishing to comment on the EA may do so. Your comments should focus on the EA’s disclosure and discussion of potential environmental effects, reasonable alternatives, and measures to avoid or lessen environmental impacts. The more specific your comments, the more useful they will be. To ensure that the Commission has the opportunity to consider your comments prior to making its decision on this project, it is important that we receive your comments in Washington, DC on or before 5:00 pm Eastern Time on June 12, 2023.

For your convenience, there are three methods you can use to file your comments to the Commission. The Commission encourages electronic filing of comments and has staff available to assist you at (866) 208-3676 or Please carefully follow these instructions so that your comments are properly recorded.

  1. You can file your comments electronically using the eComment feature on the Commission’s website ( under the link to FERC Online. This is an easy method for submitting brief, text-only comments on a project;
  2. You can also file your comments electronically using the eFiling feature on the Commission’s website ( under the link to FERC Online. With eFiling, you can provide comments in a variety of formats by attaching them as a file with your submission. New eFiling users must first create an account by clicking on “eRegister.” You must select the type of filing you are making. If you are filing a comment on a particular project, please select “Comment on a Filing”; or
  3. You can file a paper copy of your comments by mailing them to the Commission. Be sure to reference the project docket number (CP23-3-000) on your letter. Submissions sent via the U.S. Postal Service must be addressed to: Kimberly D. Bose, Secretary, Federal Energy Regulatory Commission, 888 First Street NE, Room 1A, Washington, DC 20426. Submissions sent via any other carrier must be addressed to: Kimberly D. Bose, Secretary, Federal Energy Regulatory Commission, 12225 Wilkins Avenue, Rockville, MD 20852.

Filing environmental comments will not give you intervenor status, but you do not need intervenor status to have your comments considered. Only intervenors have the right to seek rehearing or judicial review of the Commission’s decision. At this point in this proceeding, the timeframe for filing timely intervention requests has expired. Any person seeking to become a party to the proceeding must file a motion to intervene out-of-time pursuant to Rule 214(b)(3) and (d) of the Commission’s Rules of Practice and Procedures (18 CFR 385.214(b)(3) and (d)) and show good cause why the time limitation should be waived. Motions to intervene are more fully described at

Additional information about the project is available from the Commission’s Office of External Affairs, at (866) 208-FERC, or on the FERC website ( using the eLibrary link. The eLibrary link also provides access to the texts of all formal documents issued by the Commission, such as orders, notices, and rulemakings.

In addition, the Commission offers a free service called eSubscription which allows you to keep track of all formal issuances and submittals in specific dockets. This can reduce the amount of time you spend researching proceedings by automatically providing you with notification of these filings, document summaries, and direct links to the documents. Go to to register for eSubscription.

Documents & Docket Numbers

Contact Information

This page was last updated on May 12, 2023