GREAT BASIN GAS TRANSMISSION COMPANY — Integrity Assurance Notification

CROSSOVER RMV ALTERNATIVE TECHNOLOGYGreat Basin Gas Transmission Company (Great Basin), a wholly-owned subsidiary of Southwest Gas Corporation, will be upsizing approximately 2.88 miles of their existing 10” Carson Lateral Pipeline (the light blue line in Exhibit A), as well as installing seven new Rupture Mitigation Valves (RMV). Additionally, two valves that are normally closed will be locked out and tagged out per 49 CFR Part 192.634(b)(4). Great Basin is requesting PHMSA’s permission to lock these valves into the closed position in lieu of a Rupture Mitigation Valve per that regulation. Installing new RMVs where valves currently exist and can be locked in the closed position is unpractical and not operationally necessary. Each of these valves are essential valves and are inspected and maintained annually, not to exceed 15 months.#