TRANSCONTINENTAL GAS PIPE LINE COMPANY — Gas transmission and gathering — incident on 2018-06-29

Gas transmission and gathering incident. Reported cause: CORROSION FAILURE. Reported consequences: 0 fatalities, 0 injuries, 48 NATURAL GAS released, $1,933,000 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: 20180079.

Operator ID: 19570.

Reported incident date: 6/29/2018 15:15.

Cause detail: INTERNAL CORROSION

Cause detail: ON 06/29/2018 A THIRD PARTY HELICOPTER SPOTTED THE BUBBLES AND REPORTED THEM TO WGP PIPELINE CONTROL. PIPELINE CONTROL NOTIFIED WGP OPERATIONS. OPERATIONS FLEW OUT TO VERIFY COORDINATES. THE BUBBLES WERE IN THE VICINITY OF A WGP 16" PIPELINE. THE WGP SECURITY OPERATIONS CENTER WAS NOTIFIED OF THE POTENTIAL LEAK. AT 16:30 ON 6/29/18 WILLIAMS OPERATOR ARRIVED AND REPORTED THAT THERE WAS 606PSI ON THE PREVIOUSLY ISOLATED SECTION OF PIPELINE. DUE TO A LEAKING ISOLATION VALVE AND A BLEED VALVE THAT HAD BEEN CLOSED, THE PRESSURE ON THE LINE WAS CAUSED DUE TO THERMAL EXPANSION. HE THE STARTED BLOWING DOWN THE LINE DUE TO THE FINDINGS AND LEAK LOCATION. ON 6/30/2018 AT 16:30 THE BUBBLES STOPPED. AT 17:20 ON 6/30/2018 THE LINE WAS AT ZERO AND NOTIFICATIONS WERE MADE. THE LINE REMAINS OUT OF SERVICE AT THIS TIME. AWAITING ABANDONMENT PLAN. 12/25/18 LINE REMAINS OUT OF SERVICE. ABANDONMENT EXPECTED 2019/2020. 2/11/2019 PLEASE EXPLAIN HOW 606 PSI WAS ON THE PREVIOUSLY ISOLATED SECTION OF PIPE? THERE WAS A LEAKING ISOLATION VALVE AND A BLEED VALVE HAD BEEN CLOSED. DUE TO THE THERMAL EXPANSION, THIS CAUSED THE PRESSURE ON THIS ISOLATED SEGMENT OF PIPE. IS THE ENTIRE LINE BEING ABANDONED OR ARE THERE OTHER SECTIONS THAT MAY BE SUSCEPTIBLE? THE ENTIRE LINE IS PLANNED FOR ABANDONMENT. IS THE ENTIRE SECTION THAT WILL BE ABANDONED ISOLATED? YES, AND VENTED. WILL THERE BE ANY CHANGES TO THE INTERNAL CORROSION CONTROL PROGRAM? OPERATIONS HAS CHANGED THE TYPE OF CORROSION INHIBITOR USED PER REQUEST BY THE PIPELINE INTEGRITY GROUP. THEY ARE NOT SURE IF IT WOULD HAVE HELPED THIS SECTION, DUE IT TO NOT BEING PIGGABLE. 5/9/2021 UPDATE A PROJECT OF THIS SIZE REQUIRED TRANSCO TO OBTAIN A FERC PRIOR NOTICE APPLICATION BEFORE STARTING ANY WORK WHICH IS A 60 DAY PROCESS AFTER ALL PERMITS ARE IN HAND. BEFORE SUBMITTING THE FERC PERMIT, TRANSCO NEEDED TO FIRST OBTAIN THE BSEE PERMITS TO RELINQUISH THE ROW(S). ON OCTOBER 28TH, 2019, TRANSCO REQUESTED PERMITS TO BSEE TO RELINQUISH OUR ROW FOR THE FOUR (4) PIPELINES WHICH MAKE UP THE SYSTEM ABANDONMENT AND WERE ORIGINALLY EXPECTING THEM BACK IN Q1 OR AT THE LATEST Q2 OF 2020 TO ENSURE ENOUGH TIME TO SUBMIT OUR FERC APPLICATION. TRANSCO HAD RECEIVED THE TOTAL 4 BSEE PERMITS IN LATE AUGUST/EARLY SEPTEMBER OF 2020. FERC NOTICE TO PROCEED WAS NOT ISSUED UNTIL NOVEMBER. BECAUSE NOVEMBER IS OUTSIDE THE TYPICAL OFFSHORE WORKING SEASON, THE SCHEDULE TO ABANDON THESE PIPELINES WAS SHIFTED TO THE 2021 WORK SEASON TO ENSURE WE DO NOT PLACE PERSONNEL AND ANY CONTRACTORS AT AN INCREASED RISK OF INJURY. ABANDONMENT WORK IS SET TO BEGIN AT THE END OF THIS MONTH, MAY 2021. PIPELINE WAS DISCONNECTED AND DECOMMISSIONED IN JULY 2021.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: CORROSION — INTERNAL.

PHMSA indexed costs: $1,941,653 reported total cost, $928,169.209 in 1984 dollars, $2,284,119.642 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.