HAWAI`IGAS — Gas distribution — incident on 2015-06-15

Gas distribution incident in HONOLULU, HONOLULU County, HI. Reported cause: EXCAVATION DAMAGE. Reported consequences: 0 fatalities, 1 injuries, 160 SYNTHETIC GAS released, $100,000 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20150070.

Operator ID: 6243.

Reported incident date: 6/15/2015 21:30.

Location detail: 645 KAPAHULU AVE

Cause detail: EXCAVATION DAMAGE BY THIRD PARTY

Cause detail: EXCAVATION ISSUE

Cause detail: IMPROPER EXCAVATION PRACTICE NOT LISTED ABOVE

Cause detail: INCIDENT SUMMARY ON 06/15/2015, ROAD BUILDERS ("RB") WAS COLD PLANING A PORTION OF KAPAHULU AVENUE IN HONOLULU WITH AN ASPHALT MILLING MACHINE. BETWEEN 2115 AND 2130, THE MACHINE STRUCK A HAWAII GAS ("HG") UNDERGROUND MAIN LINE, CAUSING AN APPROXIMATELY 9.5-INCH TEAR IN THE MAIN. THE DAMAGED SEGMENT WAS 4-INCH STEEL PIPE COATED WITH XTC ("SUBJECT SEGMENT"). THE SUBJECT SEGMENT BEGAN TO LEAK GAS AND AT AN UNVERIFIED TIME, THE GAS IGNITED AROUND THE MACHINE. TWO RB EMPLOYEES WERE INJURED IN CONNECTION WITH THE FIRE AND ONE REQUIRED INPATIENT HOSPITALIZATION. THE HONOLULU FIRE DEPARTMENT ("HFD") RESPONDED AND DIRECTED WATER AT THE MACHINE TO PREVENT ITS FUEL TANKS FROM OVERHEATING. HG STOPPED THE FLOW OF GAS TO THE SUBJECT SEGMENT AT APPROXIMATELY 0253 ON 06/16/2015, THE FIRE DISSIPATED SHORTLY THEREAFTER AND HFD ANNOUNCED AN "ALL CLEAR" AT APPROXIMATELY 0300. HG PRE-INCIDENT ACTIVITY HG INSTALLED THE SUBJECT SEGMENT IN 1977. ON 02/09/2015, RB SUBMITTED ONE CALL TICKET 15001196 (THE "TICKET") TO THE HAWAII ONE CALL CENTER STATING THAT RB WOULD BE EXCAVATING AN AREA OF KAPAHULU AVENUE (THE "EXCAVATION AREA"), INCLUDING THE SUBJECT SEGMENT. HG RESPONDED TO THE TICKET BY REVIEWING EXCAVATION AREA MAPS AND DETERMINING THAT AN UNDERGROUND MAIN WAS LOCATED THEREIN. ON 02/19/2015, HG PERFORMED CONDUCTIVE AND INDUCTIVE TONING IN THE EXCAVATION AREA AND MARKED THE APPROXIMATE LOCATION OF THE MAIN LINE ON THE ROADWAY SURFACE WITH YELLOW PAINT. HG RESPONSE TO INCIDENT HG WAS ALERTED TO THE INCIDENT IN TWO WAYS: 1) THE HG SYNTHETIC NATURAL GAS PLANT RECORDED A PRESSURE IRREGULARITY IN THE GAS PIPELINE AND NOTIFIED HG DISPATCH AT APPROXIMATELY 2130; AND 2) HFD NOTIFIED HG DISPATCH AT APPROXIMATELY 2138. AN HG OPERATIONS SUPERINTENDENT ARRIVED AT THE SCENE AT APPROXIMATELY 2200. OTHER HG PERSONNEL WERE NOTIFIED BETWEEN 2145 AND 2215, AND BEGAN ARRIVING AT THE HG KAMAKEE BASEYARD BETWEEN 2215 AND 2300. THE HG SUPERVISORY TEAM CONCLUDED THAT THE MAIN LINE WOULD NEED TO BE EXCAVATED AND STOPPED AT THREE LOCATIONS: NORTH, SOUTH AND WEST OF THE INCIDENT. HG PERSONNEL INSTALLED LINE STOPPERS AT THE NORTH AND SOUTH SITES AND PINCHED THE LINE AT THE WEST SITE. GAS FLOW TO THE SUBJECT SEGMENT WAS STOPPED AT APPROXIMATELY 0253 ON 06/16/15. STATUTORY AND REGULATORY CONTEXT (1) HAWAII ONE CALL STATUTE THE HAWAII ONE CALL STATUTE REQUIRES AN EXCAVATOR TO PROVIDE EXCAVATION LOCATION TO THE ONE CALL CENTER PRIOR TO EXCAVATING, AND THE CENTER NOTIFIES UTILITY OPERATORS ABOUT THE PROPOSED EXCAVATION. THE OPERATOR LOCATES AND MARKS ON THE ROADWAY THE APPROXIMATE LOCATION OF INSTALLATIONS THAT MAY BE AFFECTED BY THE EXCAVATION, BUT IS NOT REQUIRED TO MARK DEPTH UNDER THE STATUTE. THE EXCAVATOR MUST THEN USE HAND TOOLS TO DETERMINE THE EXACT LOCATION OF THE INSTALLATION. HERE, HG RESPONDED TO THE TICKET BY REVIEWING MAPS, PERFORMING TONING AND MARKING THE ALIGNMENT--BUT NOT DEPTH--OF THE GAS MAIN IN THE EXCAVATION AREA WITH YELLOW PAINT. HG WAS IN FULL COMPLIANCE WITH THE ONE CALL STATUTE. RB DOES NOT APPEAR TO HAVE HAND EXCAVATED AND LOCATED THE SUBJECT SEGMENT IN COMPLIANCE WITH THE STATUTE. (2) SUBJECT SEGMENT DEPTH FEDERAL REGULATIONS IN 1977 REQUIRED 24-INCH COVER FOR A MAIN LINE. A MAIN LINE CAN BE INSTALLED WITH LESS THAN 24-INCH COVER IF AN UNDERGROUND STRUCTURE PREVENTS SUCH INSTALLATION AND THE LINE IS PROVIDED WITH ADDITIONAL PROTECTION. ON 06/16/2015, THE SUBJECT SEGMENT WAS MEASURED AT APPROXIMATELY 8 INCHES BELOW THE ROADWAY SURFACE. IF THE SUBJECT SEGMENT WAS INSTALLED WITH LESS THAN 24-INCH COVER IN 1977, THE ABOVE EXCEPTION APPLIES. CITY RECORDS INDICATE THAT A CONDUIT STRUCTURE RUNS DIRECTLY BELOW THE SUBJECT SEGMENT, PREVENTING INSTALLATION OF THE SUBJECT SEGMENT AT 24-INCH DEPTH. THE SUBJECT SEGMENT WAS ENCASED IN CONCRETE, PROVIDING THE ADDITIONAL PROTECTION REQUIRED FOR MAINS INSTALLED WITH LESS THAN 24-INCH COVER. PLEASE CONTACT HG FOR ADDITIONAL NARRATIVE DETAIL IN PDF FORMAT.

PHMSA trend classification: significant incident, serious incident, not fire-first.

PHMSA standardized cause: EXCAVATION DAMAGE — THIRD PARTY EXCAVATION DAMAGE.

PHMSA indexed costs: $613,900 reported total cost, $309,632.961 in 1984 dollars, $758,065.248 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.