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Notice

Gexcon U.S., Inc.'s Petition for EFFECTS Version 12.2.0 as an Alternative Model for Calculating the Vapor-Gas Dispersion Exclusion Zone

A Notice by the Pipeline and Hazardous Materials Safety Administration on 09/09/2026

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Published Document: 2026-18346 (91 FR 57446)

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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Department of Transportation
Pipeline and Hazardous Materials Safety Administration
  1. [Docket No. PHMSA-2024-0164]

AGENCY:

Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT).

ACTION:

Notice.

SUMMARY:

PHMSA is publishing this notice and a draft letter of decision to solicit public comment on a petition for approval that would authorize the use of an alternate flammable vapor-gas dispersion model in connection with the siting of liquefied natural gas (LNG) facilities.

DATES:

Submit any comments regarding the petition by October 9, 2026.

ADDRESSES:

Comments should reference the docket number for the petition request and may be submitted in one of the following ways:

  • E-Gov Web: www.regulations.gov. This site allows the public to enter comments on any Federal Register Notice issued by any agency. Follow the online instructions for submitting comments.
  • Mail: Docket Management System: U.S. Department of Transportation, 1200 New Jersey Avenue SE, West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
  • Hand Delivery: DOT Docket Management System: West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, between 9:00 a.m. and 5:00 p.m. EST, Monday through Friday, except Federal holidays.
  • Fax: 202-493-2251.
  • Instructions: You should identify the docket number for the petition request you are commenting on at the beginning of your comments. If you submit your comments by mail, please submit two copies. To receive confirmation that PHMSA has received your comments, please include a self-addressed stamped postcard. Internet users may submit comments at www.regulations.gov.
  • Note: There is a privacy statement published; to review the statement, go to www.regulations.gov, scroll down to the bottom left to click “Privacy & Security Notice.” Comments, including any personal information provided, are posted without changes or edits to www.regulations.gov.
  • Confidential Business Information: Confidential Business Information (CBI) is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (5 U.S. Code 552), CBI is exempt from public disclosure. If your comments in response to this notice contain commercial or financial information that is customarily treated as private, which you actually treat as private, and that is relevant or responsive to this notice, it is important that you clearly designate the submitted comments as CBI. Pursuant to 49 CFR 190.343, you may ask PHMSA to provide confidential treatment to information you give to the agency by taking the following steps: (1) mark each page of the original document submission containing CBI as “Confidential”; (2) send PHMSA a copy of the original document with the CBI deleted along with the original, unaltered document; and (3) explain why the information you are submitting is CBI. Submissions containing CBI should be sent to Mr. Lee Cooper, 1200 New Jersey Avenue SE, DOT: PHMSA-PHP-80, Washington, DC 20590-0001. Any commentary PHMSA receives that is not specifically designated as CBI will be placed in the public docket.
  • Privacy Act: DOT may solicit comments from the public regarding certain general notices. DOT posts these comments, without edits, including any personal information the commenter provides, to www.regulations.gov, as described in the system of records notice (DOT/ALL-14 FDMS), which can be reviewed at www.dot.gov/​privacy.
  • Docket: For access to the docket to read background documents or comments received, go to www.regulations.gov. Follow the online instructions for accessing the dockets. Alternatively, you may review the documents in person at the street address listed above.

FOR FURTHER INFORMATION CONTACT:

General: Mr. Lee Cooper by phone at 202-913-3171 or by email at .

Technical: Mr. Thach Nguyen by phone at 909-262-4464 or by email at .

SUPPLEMENTARY INFORMATION:

PHMSA is evaluating a petition from Gexcon U.S., Inc. (Gexcon) requesting approval, pursuant to 49 CFR 190.9, authorizing use of its EFFECTS v12.2.0 (EFFECTS v12.2) software as an alternate model for calculating, pursuant to 49 CFR 193.2059, the flammable vapor-gas dispersion exclusion zones for 49 CFR part 193-regulated LNG facilities. ( printed page 57447)

PHMSA's safety standards for the siting of LNG facilities are found in subpart B of 49 CFR part 193. Section 193.2059 requires that each LNG container and LNG transfer system must have a flammable vapor-gas dispersion exclusion zone, defined as the area surrounding an LNG facility in which an operator or government agency legally controls all activities. The exclusion zone is intended to protect the public from the flammable vapor gas and direct exposure to the flame in the event of a release or ignition, respectively. In accordance with 49 CFR 193.2059(a), an LNG operator must calculate vapor-gas dispersion exclusion zones using either the DEGADIS 2.1 Dense Gas Dispersion model or FEM3A model. Section 193.2059 also states that the Administrator (or his delegate) may, pursuant to the procedures set forth in 49 CFR 190.9, approve the use of alternative vapor-gas dispersion models that take into account the same physical factors as those considered in the development of the DEGADIS 2.1 and FEM3A models, and which have been validated by experimental test data.

On December 11, 2023, Gexcon petitioned PHMSA for approval of its EFFECTS v12.2 software as an alternate model for calculating the LNG flammable vapor-gas dispersion exclusion zones. The petition and draft letter of decision for EFFECTS v12.2 are available for review and public comment in Docket No. PHMSA-2024-0164.

Before issuing a final decision on Gexcon's petition, PHMSA will evaluate all comments received on or before the comment closing date. Comments received after the closing date will be evaluated if it is possible to do so without incurring additional expenses or delay. PHMSA will consider each relevant comment we receive in making our final decision to grant or deny this request.

Issued in Washington, DC, under authority delegated in 49 CFR 1.97.

Thomas Correll,

Associate Administrator for Pipeline Safety.

[FR Doc. 2026-18346 Filed 9-8-26; 8:45 am]

BILLING CODE 4910-60-P

Published Document: 2026-18346 (91 FR 57446)