Intermountain Gas Rexburg LNG Incident Follow- up IPUC Form 1

Idaho PUC Pipeline Safety Inspection Summary
Inspector(s): I Perkins(4.5)/Brooks(2.0) I Date(s): 8/13/2024
Company/Owner: (IGC) Intermountain Gas Company Unit/OPID: Rexburg/816
Inspection Type &Time (1 day, 0.5 day) Total Inspection Days:1 6.5
Standard:F1 Construction:F-] Training: D (T)(D)Integrity Management: a Incident: El
M/M: F1 Follow-up: F-1 OQ: F-1 Damage Prevention: D&A:
Inspection Summary
Follow-up incident/investigation of the 16 July 2024, IGC LNG plant Emergency Shutdown and
8900 gallon spill from transfer trailer in Rexburg, Idaho. Federal reportable incident NRC#
1404942/1405150.
17-18 July 2024: (2.0 Inspection/investigation, 1.0 Travel)
A follow-up incident/investigation was conducted by the Idaho Public Utilities Commission's Pipeline
Safety Division on Intermountain Gas Companies (IGC) LNG Plant in Rexburg following an Emergency
Shutdown. The incident/investigation has determined that the cause of the incident is operator
error/failure to follow procedures, resulting in the loss of approximately 8900 gallons of LNG.
30 July/12/13 August 2024: (3.5 Typed Report/Compliance follow-up)
Reference documents:
49 CFR §193.2503 Operating Procedures, 49 CFR §193.2513 Transfer Procedures, IGC-Rexburg LNG
Transfer Operations Procedure 4565, Rexburg LNG Truck Off Loading Operations Checklist, NFPA
59A Standard for the Production, Storage, and Handling of Liquified Natural Gas (LNG) 2001 Edition.
Observations:
1. Vaporization Tech(Vap. Tech) did not Verify LNG trailer vent valve and fill valve are closed before
connecting/disconnecting hoses.
2. Carrier/driver did not verify valves were in the proper position for operations.
3. Vap. Tech did not accurately complete items on Rexburg LNG Truck Off Loading Operations
Checklist prior to beginning transfer operations. Items #1, #3, #8.
4. Vap. Techs were unfamiliar and did not know the locations of ESV (Emergency Shutdown Valves)
(per carrier/driver) on trailer, prior to the LNG spill incident.
5. Vap. Tech at the off-loading skid did not have Procedure 4565 located/present for cargo transfer.
6. Vap. Tech did not ensure Carrier completed requirements in IGC-Rexburg LNG Transfer Operations
Procedure 4565.
7. Personnel involved in LNG transfer operations, were not familiar with the correct positions of the
valves on LNG trailer, prior to commencing off-load operations.
8. ESV valve on LNG trailer malfunctioned and did not close completely when activated.
IPUC Form 1

Idaho PUC Pipeline Safety Inspection Summary
Contributing Factors:
Vap. Techs did not follow procedures 49 CFR §193.2513 Transfer Procedures, NFPA 59A Standard for
the Production, Storage, and Handling of Liquified Natural Gas (LNG) 2001 Edition, IGC-Rexburg
LNG Transfer Operations Procedure 4565, did not have a copy of Procedure 4565 at offloading skid, or
accurately complete the Rexburg LNG Truck Off Loading Operations Checklist prior to transfer
operations.
Reccomendations:
IGC LNG Techs and all personnel involved in LNG operations need to comply with 49 CFR §193.2503
Operating Procedures as required.
Change Rexburg LNG Transfer Operations Checklist, to ensure carrier/driver completes tasks as
required in IGC-Rexburg LNG Transfer Operations Procedure 4565.
Attachments:
IGC Form 23001 MDUG Incident or Hazardous Condition Report
IGC Follow up letter to Rexburg LNG Incident July 16 ,2024, dated Aug 1, 2024
IRC Event Log(22106)
AID Correspondance
Misc. photos
Corrective Action Required: Follow-up Required: Yes X No
Yes X NoF X NOPV 1202408 by(date):
Inspector(Lead): Date:
Reviewer: Date:
IPUC Form 1