LINDE — Gas transmission and gathering — incident on 2019-05-05

Gas transmission and gathering incident in BAYTOWN, HARRIS County, TX. Reported cause: NATURAL FORCE DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 65.4 HYDROGEN GAS released, $400,000 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: 20190063.

Operator ID: 20044.

Reported incident date: 5/5/2019 17:30.

Location detail: 105+72.74

Cause detail: LIGHTNING

Cause detail: AT 1730 ON 5 MAY 2019, PRAXAIR WAS NOTIFIED BY A THIRD PARTY THAT THERE WAS A POSSIBLE LEAK ON ITS HYDROGEN PIPELINE, AS IDENTIFIED BY SOUND. PRAXAIR PERSONNEL ARRIVED ON THE SITE AT 1830 AND CONFIRMED THAT HYDROGEN WAS PRESENT IN THE AREA. THE LOCATION WAS IN AN ISOLATED AREA. MANUAL ISOLATION VALVES WERE SHUT TO CLOSE IN THE SEGMENT AND IT WAS MANUALLY BLOWN DOWN. AT 0852 ON 6 MAY 2019, PRAXAIR DETERMINED THAT THE INCIDENT MET REPORTABLE CRITERIA AND CALLED THE NATIONAL RESPONSE CENTER AT 0922. BLOWDOWN OF THE ISOLATED SEGMENT WAS COMPLETED AT 1230 ON 6 MAY 2019. THERE WAS NO IMMEDIATELY RECOGNIZABLE CAUSE OF THE INCIDENT. NO EXCAVATORS WERE OPERATING IN THE AREA, AND CP TESTING SHOWED NO ABNORMALITIES. THE SUSPECTED AREA OF THE LEAK WAS EXCAVATED, BUT THE PIPE WAS SHOWN TO BE IN EXCELLENT CONDITION. UPON FURTHER INVESTIGATION, IT WAS DETERMINED THAT THE LEAK WAS MOST LIKELY LOCATED UNDERNEATH A SMALL NON-NAVIGABLE DRAINAGE CANAL. UNABLE TO EXCAVATE UNDER THE WATER, A NEW SEGMENT OF PIPE WAS INSTALLED, REROUTING AROUND THE LEAK. THE PIPELINE WAS PUT BACK INTO SERVICE ON 12 MAY 2019 AT 0930. IN JUNE 2019, THE INACTIVE SEGMENT OF PIPE WAS FURTHER INVESTIGATED WITH A TETHERED INLINE INSPECTION (ILI) TOOL IN ORDER TO FURTHER INVESTIGATE THE CAUSE OF THE LEAK. RESULTS SHOWED AN ANOMALY IN THE VICINITY OF A GROUNDING ROD FOR A NEARBY ELECTRICAL TRANSMISSION TOWER. AN ADDITIONAL DCVG INSPECTION SHOWED A SIMILAR ANOMALY, CORRELATING THE RESULTS OF THE ILI. IT IS THEREFORE SUSPECTED THAT LIGHTNING STRUCK THE TOWER DURING A STORM, CREATING A SURGE OF ENERGY THAT RELEASED INTO THE GROUND THROUGH THE GROUNDING ROD. THIS ELECTRICAL ENERGY CREATED THE ANOMALY ON THE PIPE WHICH EVENTUALLY LED TO THE SMALL LEAK. THE NEWLY INSTALLED SEGMENT OF PIPE IS NOT LOCATED IN THE VICINITY OF THE GROUNDING ROD. AN EXTERNAL INSPECTION COMPANY WAS HIRED TO REVIEW PIPELINE LOCATIONS WITH SIMILAR ENVIRONMENTS THROUGHOUT THE PIPELINE SYSTEM. NO OTHER ANOMALIES WERE DISCOVERED AND A SIMILAR INCIDENT IS NOT SUSPECTED TO OCCUR AGAIN.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: NATURAL FORCE DAMAGE — LIGHTNING.

PHMSA indexed costs: $500,948 reported total cost, $235,259.145 in 1984 dollars, $578,157.221 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.