SOUTHWEST GAS CORP — Integrity Assurance Notification

RMV OPERATIONAL DELAYPursuant to 49 CFR §192.634(a) and the notification procedures in §192.18, Southwest Gas Corporation (Southwest Gas) hereby submits this letter to formally request an extension of time to make the associated rupture mitigation valves (RMVs) operational for the Lamb Tap Project located in North Las Vegas, NV. This new pressure limiting station and RMVs are scheduled to be placed into service September 23, 2026. An overview map of the project has been attached for your reference. As acknowledged by PHMSA in the Notice of Proposed Rulemaking titled “Pipeline Safety: Timeframe to Make RMVs Operational” (FR Doc. 2026-08076, published April 24, 2026), the currently required 14-day timeframe can be impracticable due to real-world construction, commissioning, and integration challenges. PHMSA specifically recognized that operators may require additional time due to synchronizing RMVs into Supervisory Control and Data Acquisition (SCADA) systems. Our request is consistent with these considerations and reflects circumstances that are operationally and technically infeasible to resolve within the prescribed timeframe despite diligent planning and execution. While the valves will be mechanically functional, additional time is necessary to complete final testing, remote operability verification, and system synchronization to ensure full compliance and safe operation. Safety remains our highest priority. During the requested extension period, the pipeline segment will continue to be monitored using existing control measures and procedures, and manual valve operation remains available if needed.#