SOUTHWEST GAS CORP

Incident Narrative

A HAZARDOUS GRADE 1 LEAK WAS DISCOVERED BY CONTRACTOR PERSONNEL (HEATH CONSULTANTS, INC.). THE LEAK WAS DISCOVERED WHILE PERFORMING LEAK SURVEYING WORK IN EXCESS OF THE MINIMUM REQUIREMENTS OF 49 CFR PART 192. THE FLOW OF GAS TO THE SECTION OF PIPE WAS TAKEN OUT OF SERVICE WHILE REPAIRS WERE COMPLETED, WHICH RESULTED IN A SERVICE OUTAGE OF 2092 CUSTOMERS. PART A, 6: SOUTHWEST GAS NOTIFIED THE NATIONAL RESPONSE CENTER (NRC) TELEPHONICALLY OF THE INCIDENT ON SEPTEMBER 27, 2017 AT 11:34 AM PDT. THE NRC ISSUED REPORT NUMBER 1191661 FOR THE INCIDENT. SOUTHWEST GAS PROVIDED A 48-HOUR UPDATE TELEPHONICALLY TO THE NRC ON SEPTEMBER 28, 2017 AT 4:29 PM PDT. THE NRC ISSUED REPORT NUMBER 1191822 FOR THE UPDATED REPORT. PART A, 16: FOUR OCCUPANTS WERE EVACUATED FROM TWO STRUCTURES AS A RESULT OF THE INCIDENT. PART G, 25: A CONTRIBUTING FACTOR WAS POOR SHADING (I.E., MATERIAL PLACED BETWEEN THE PIPE AND THE FIRST LAYER OF BACKFILL) WHICH WAS NOTED ADJACENT TO THE LEAK, WITH BACKFILL MATERIAL CONSISTING OF A MIXTURE OF SAND AND ROCK. SUPPLEMENTAL: BASED ON COMMUNICATIONS THE PUBLIC UTILITIES COMMISSION OF NEVADA'S REGULATORY OPERATIONS STAFF (""STAFF"") HAD WITH THE PIPELINE AND HAZARDOUS MATERIAL SAFETY ADMINISTRATION'S ACCIDENT INVESTIGATION DIVISION REGARDING THE INCIDENT REPORT - GAS DISTRIBUTION SYSTEMS FILED BY SOUTHWEST GAS CORPORATION FOR THE SEPTEMBER 27, 2017, FEDERAL REPORTABLE INCIDENT AT WIGWAM PARKWAY AND JESSUP ROAD; STAFF REQUESTED THAT SOUTHWEST GAS CORPORATION SUPPLEMENT THE REPORT TO UPDATE PART A- LINE 4 ""LOCAL TIME AND DATE OF THE INCIDENT."" PART A, 4: INCIDENT REPORTING TIME HAS BEEN CHANGED FROM 11:19 TO 08:04. THE TIME REPORTED IN PART A, 4 (08:04) REFLECTS THE TIME OUR CONTRACTOR PERSONNEL (HEATH CONSULTANTS, INC.) IDENTIFIED AND REPORTED A GRADE 1 LEAK ON THE PIPELINE. AT THAT TIME, NO REPORTING CRITERIA HAD BEEN MET. THE SHUTDOWN TIME REPORTED IN PART A, 13A (11:19) IS THE EARLIEST DATE AND TIME A REPORTING CRITERIA WAS MET. DUE TO THE SHUTDOWN OF THE PIPELINE, THE INCIDENT WAS ESTIMATED TO REACH PROPERTY DAMAGE OF $50,000 OR MORE. TELEPHONIC NOTIFICATION WAS MADE WITHIN ONE HOUR OF THE SHUTDOWN TIME. SUPPLEMENTAL 2: PART D, 2C: ESTIMATED COST OF OPERATOR'S EMERGENCY RESPONSE HAS BEEN UPDATED FROM $140,298 TO $110,025